v0.1.0 - CYD firmware v0.0.2: algorithm-based API upgrade (all verbs, all algorithms), vendored Keccak/SHAKE + PSA ed25519/x25519 for IDF v5.4, Web Serial test page, CYD docs, Teensy 4.1 port plan (1TB SDXC OTP pad), brainstorming READMEs for BLE/IR/NFC/FPGA signer concepts

.test_mnemonic_otp_roundtrip.tmp

@@ -0,0 +1,13 @@
+alarm impact educate burden vague honey horn buyer sight vocal age render
+
+index 0
+
+{
+  "index": 0,
+  "nsec": "nsec1z2lrfamae2dzax7dmnlhv497uuxe4mw0m3w694upx5x54q6dgttqvzrrwl",
+  "npub": "npub1j7d7yf47w8k2kseknqjr3045jvm00u0wnt3433kk6vu67d2zamcs8ynuw4",
+  "npubHex": "979be226be71ecab4336982438beb49336f7f1ee9ae358c6d6d339af3542eef1",
+  "nsecHex": "12be34f77dca9a2e9bcddcff7654bee70d9aedcfdc5da2d781350d4a834d42d6",
+  "fipsIpv6": "fd55:b7c6:536e:26ee:a79:6e25:6f05:a85f",
+  "strDerivationPath": "m/44'/1237'/0'/0/0"
+}

Dockerfile.alpine-musl

@@ -55,6 +55,7 @@ RUN if [ "$(uname -m)" = "aarch64" ] && ! command -v aarch64-linux-gnu-gcc >/dev
 
 # Copy source files
 COPY src/ /build/src/
+COPY libotppad/ /build/libotppad/
 COPY resources/tui_continuous/ /build/resources/tui_continuous/
 COPY resources/pqclean/ /build/resources/pqclean/
 
@@ -76,6 +77,7 @@ RUN ARCH="$(uname -m)"; \
       -I/build/resources/pqclean/crypto_sign/ml-dsa-65 \
       -I/build/resources/pqclean/crypto_sign/slh-dsa-128s \
       -I/build/resources/pqclean/crypto_kem/ml-kem-768 \
+      -I/build/libotppad \
       /build/src/main.c \
       /build/src/secure_mem.c \
       /build/src/mnemonic.c \
@@ -92,6 +94,9 @@ RUN ARCH="$(uname -m)"; \
       /build/src/miner.c \
       /build/src/pq_crypto.c \
       /build/src/pq_drbg.c \
+      /build/src/otp_pad.c \
+      /build/src/http_listener.c \
+      /build/libotppad/libotppad.c \
       /build/resources/pqclean/crypto_sign/ml-dsa-65/sign.c \
       /build/resources/pqclean/crypto_sign/ml-dsa-65/poly.c \
       /build/resources/pqclean/crypto_sign/ml-dsa-65/ntt.c \

Makefile

@@ -1,5 +1,5 @@
 CC := gcc
-CFLAGS := -Wall -Wextra -std=c99 -Os -ffunction-sections -fdata-sections -DNOSTR_ENABLE_NSIGNER_CLIENT=1 -D_GNU_SOURCE -Isrc -Iresources/nostr_core_lib -Iresources/nostr_core_lib/nostr_core -Iresources/nostr_core_lib/cjson -Iresources/tui_continuous -Iresources/pqclean -Iresources/pqclean/crypto_sign/ml-dsa-65 -Iresources/pqclean/crypto_sign/slh-dsa-128s -Iresources/pqclean/crypto_kem/ml-kem-768 -Iresources/pqclean/common
+CFLAGS := -Wall -Wextra -std=c99 -Os -ffunction-sections -fdata-sections -DNOSTR_ENABLE_NSIGNER_CLIENT=1 -D_GNU_SOURCE -Isrc -Ilibotppad -Iresources/nostr_core_lib -Iresources/nostr_core_lib/nostr_core -Iresources/nostr_core_lib/cjson -Iresources/tui_continuous -Iresources/pqclean -Iresources/pqclean/crypto_sign/ml-dsa-65 -Iresources/pqclean/crypto_sign/slh-dsa-128s -Iresources/pqclean/crypto_kem/ml-kem-768 -Iresources/pqclean/common
 LDFLAGS := -Wl,--gc-sections resources/nostr_core_lib/libnostr_core_x64.a -lz -ldl -lpthread -lm -lssl -lcrypto -lcurl -lsecp256k1
 
 SRC_DIR := src
@@ -52,6 +52,9 @@ SOURCES := \
 	$(SRC_DIR)/miner.c \
 	$(SRC_DIR)/pq_crypto.c \
 	$(SRC_DIR)/pq_drbg.c \
+	$(SRC_DIR)/otp_pad.c \
+	$(SRC_DIR)/http_listener.c \
+	libotppad/libotppad.c \
 	$(PQCLEAN_SOURCES) \
 	resources/tui_continuous/tui_continuous.c
 
@@ -179,7 +182,7 @@ examples: $(EXAMPLE_GET_PUBLIC_KEY_TARGET) $(EXAMPLE_SIGN_EVENT_TARGET) $(EXAMPL
 
 $(TEST_MNEMONIC_TARGET): $(TEST_DIR)/test_mnemonic.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_mnemonic.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_MNEMONIC_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_mnemonic.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_MNEMONIC_TARGET) $(LDFLAGS)
 
 $(TEST_MNEMONIC_INPUT_TARGET): $(TEST_DIR)/test_mnemonic_input.c
 	@mkdir -p $(BUILD_DIR)
@@ -199,7 +202,7 @@ $(TEST_ENFORCEMENT_TARGET): $(TEST_DIR)/test_enforcement.c $(SRC_DIR)/enforcemen
 
 $(TEST_DISPATCHER_TARGET): $(TEST_DIR)/test_dispatcher.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/key_store.c $(SRC_DIR)/miner.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_dispatcher.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/key_store.c $(SRC_DIR)/miner.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_DISPATCHER_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_dispatcher.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/key_store.c $(SRC_DIR)/miner.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_DISPATCHER_TARGET) $(LDFLAGS)
 
 $(TEST_POLICY_TARGET): $(TEST_DIR)/test_policy.c $(SRC_DIR)/policy.c
 	@mkdir -p $(BUILD_DIR)
@@ -223,7 +226,7 @@ $(TEST_QREXEC_AUTH_TARGET): $(TEST_DIR)/test_qrexec_auth.c $(SRC_DIR)/auth_envel
 
 $(TEST_MINE_EVENT_TARGET): $(TEST_DIR)/test_mine_event.c $(SRC_DIR)/miner.c $(SRC_DIR)/key_store.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/dispatcher.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_mine_event.c $(SRC_DIR)/miner.c $(SRC_DIR)/key_store.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/dispatcher.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_MINE_EVENT_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_mine_event.c $(SRC_DIR)/miner.c $(SRC_DIR)/key_store.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/dispatcher.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_MINE_EVENT_TARGET) $(LDFLAGS)
 
 $(TEST_PQ_CRYPTO_TARGET): $(TEST_DIR)/test_pq_crypto.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/role_table.c
 	@mkdir -p $(BUILD_DIR)
@@ -231,27 +234,27 @@ $(TEST_PQ_CRYPTO_TARGET): $(TEST_DIR)/test_pq_crypto.c $(SRC_DIR)/pq_crypto.c $(
 
 $(TEST_ED25519_X25519_TARGET): $(TEST_DIR)/test_ed25519_x25519.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_ed25519_x25519.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_ED25519_X25519_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_ed25519_x25519.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_ED25519_X25519_TARGET) $(LDFLAGS)
 
 $(TEST_ML_DSA_65_TARGET): $(TEST_DIR)/test_ml_dsa_65.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_ml_dsa_65.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_ML_DSA_65_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_ml_dsa_65.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_ML_DSA_65_TARGET) $(LDFLAGS)
 
 $(TEST_SLH_DSA_128S_TARGET): $(TEST_DIR)/test_slh_dsa_128s.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_slh_dsa_128s.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_SLH_DSA_128S_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_slh_dsa_128s.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_SLH_DSA_128S_TARGET) $(LDFLAGS)
 
 $(TEST_ML_KEM_768_TARGET): $(TEST_DIR)/test_ml_kem_768.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_ml_kem_768.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_ML_KEM_768_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_ml_kem_768.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_ML_KEM_768_TARGET) $(LDFLAGS)
 
 $(TEST_PUBKEY_FORMAT_TARGET): $(TEST_DIR)/test_pubkey_format.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_pubkey_format.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c -o $(TEST_PUBKEY_FORMAT_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_pubkey_format.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_PUBKEY_FORMAT_TARGET) $(LDFLAGS)
 
-$(TEST_ALGORITHM_API_TARGET): $(TEST_DIR)/test_algorithm_api.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/policy.c
+$(TEST_ALGORITHM_API_TARGET): $(TEST_DIR)/test_algorithm_api.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/policy.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c
 	@mkdir -p $(BUILD_DIR)
-	$(CC) $(CFLAGS) $(TEST_DIR)/test_algorithm_api.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/policy.c -o $(TEST_ALGORITHM_API_TARGET) $(LDFLAGS)
+	$(CC) $(CFLAGS) $(TEST_DIR)/test_algorithm_api.c $(SRC_DIR)/pq_crypto.c $(SRC_DIR)/pq_drbg.c $(PQCLEAN_SOURCES) $(SRC_DIR)/key_store.c $(SRC_DIR)/dispatcher.c $(SRC_DIR)/miner.c $(SRC_DIR)/selector.c $(SRC_DIR)/enforcement.c $(SRC_DIR)/role_table.c $(SRC_DIR)/mnemonic.c $(SRC_DIR)/secure_mem.c $(SRC_DIR)/policy.c $(SRC_DIR)/otp_pad.c libotppad/libotppad.c -o $(TEST_ALGORITHM_API_TARGET) $(LDFLAGS)
 
 $(EXAMPLE_GET_PUBLIC_KEY_TARGET): $(EXAMPLES_DIR)/get_public_key_client.c
 	@mkdir -p $(BUILD_DIR)

api.md

@@ -0,0 +1,15 @@
+# n_signer API
+
+The complete, authoritative API reference is now in [`README.md`](README.md) §4 (API).
+
+It covers:
+
+- **§4.1 Request format** — JSON-RPC 2.0-style request shape.
+- **§4.2 Response format** — success/error shapes and the full error-code table.
+- **§4.3 Verbs** — the verb table (positional params + options), the `scheme` option for secp256k1, and the enforcement matrix.
+- **§4.4 Algorithms** — the algorithm table (secp256k1, ed25519, x25519, ml-dsa-65, slh-dsa-128s, ml-kem-768, otp), derivation paths, key sizes, and the OTP one-time-pad model.
+- **§4.5 Examples** — worked request/response examples for every verb.
+- **§4.6 Role-based selectors** — `nostr_index` / `role` / `role_path` for the `nostr_*` verbs.
+- **§4.7 Pre-approval** — `--preapprove` syntax for algorithm-based and Nostr verbs.
+
+For the security model, transports, and operational behavior, see [`README.md`](README.md) §1–§3 and §5–§8. For the migration plan from the legacy verb names, see [`plans/legacy_verb_aliases.md`](plans/legacy_verb_aliases.md).

client/README.md

@@ -22,8 +22,8 @@ for the full integration contract.
 |---|---|
 | `nsigner_client_t` (stack) | `nsigner_client_t*` (heap) or `nostr_signer_t*` |
 | `nsigner_client_init` / `connect_unix` / `close` | `nsigner_transport_open_unix` + `nsigner_client_new` / `nsigner_client_free` |
-| `nsigner_client_get_public_key` | `nostr_signer_get_public_key` or `nsigner_client_call(..., "get_public_key", ...)` |
-| `nsigner_client_sign_event` | `nostr_signer_sign_event` or `nsigner_client_call(..., "sign_event", ...)` |
+| `nsigner_client_get_public_key` | `nostr_signer_get_public_key` or `nsigner_client_call(..., "nostr_get_public_key", ...)` |
+| `nsigner_client_sign_event` | `nostr_signer_sign_event` or `nsigner_client_call(..., "nostr_sign_event", ...)` |
 | `nsigner_client_set_auth` | `nsigner_client_set_auth` or `nostr_signer_nsigner_set_auth` |
 | `nsigner_client_request` / `request_raw` | `nsigner_client_call` (returns parsed cJSON result) |
 
@@ -42,51 +42,47 @@ n_signer supports six algorithms: `secp256k1` (Nostr), `ed25519` (SSH),
 `x25519` (age/ECDH), `ml-dsa-65` (PQ signatures, FIPS 204), `slh-dsa-128s`
 (PQ hash-based signatures, FIPS 205), and `ml-kem-768` (PQ KEM, FIPS 203).
 
-Use `nsigner_client_call(client, "<verb>", params, &result)` with these verbs:
-
-| Verb | Algorithms | Description |
-|---|---|---|
-| `get_public_key` | all | Returns the role's public key (see format below) |
-| `sign_event` | secp256k1 | Sign a Nostr event (existing) |
-| `nip44_encrypt` / `nip44_decrypt` | secp256k1 | NIP-44 (existing) |
-| `nip04_encrypt` / `nip04_decrypt` | secp256k1 | NIP-04 (existing) |
-| `mine_event` | secp256k1 | NIP-13 PoW mining + sign (existing) |
-| `sign_data` | ed25519, ml-dsa-65, slh-dsa-128s | Sign arbitrary bytes (hex) |
-| `verify_signature` | ed25519, ml-dsa-65, slh-dsa-128s | Verify a signature against the role's pubkey |
-| `ssh_sign` | ed25519 | Sign an SSH authentication challenge |
-| `kem_encapsulate` | ml-kem-768 | Encapsulate with a peer's ML-KEM public key |
-| `kem_decapsulate` | ml-kem-768 | Decapsulate a ciphertext with the role's ML-KEM private key |
-
-### Algorithm-based API (new)
-
-In addition to the role-based verbs above, the signer supports algorithm-based verbs where the caller specifies `algorithm` and `index` directly, without needing a role:
+The API has two verb families (see [`README.md`](../README.md#4-api) §4 for the full spec):
+
+**Algorithm-based verbs** — the caller specifies `algorithm` and `index` in the
+options object. No role table entry is needed.
 
 | Verb | Algorithms | Description |
 |---|---|---|
+| `get_public_key` | all key-deriving algorithms | Returns the derived public key (structured) |
 | `sign` | secp256k1, ed25519, ml-dsa-65, slh-dsa-128s | Sign arbitrary bytes (hex) |
 | `verify` | secp256k1, ed25519, ml-dsa-65, slh-dsa-128s | Verify a signature |
 | `encapsulate` | ml-kem-768 | KEM encapsulation with peer's public key |
 | `decapsulate` | ml-kem-768 | KEM decapsulation with derived private key |
 | `derive_shared_secret` | x25519 | ECDH key agreement |
-| `get_public_key` (with `algorithm`) | all | Get public key for a derived key |
+| `derive` | secp256k1 | `HMAC-SHA256(privkey, data)` — key-derived MAC for opaque identifiers (`index` required) |
+| `encrypt` / `decrypt` | otp | One-time pad encrypt/decrypt (`algorithm:"otp"`) |
+
+**Nostr protocol verbs** — select a secp256k1 NIP-06 key via `nostr_index` (or
+`role`/`role_path`). These are role-based.
+
+| Verb | Description |
+|---|---|
+| `nostr_get_public_key` | Returns the role's secp256k1 public key |
+| `nostr_sign_event` | Sign a Nostr event |
+| `nostr_mine_event` | NIP-13 PoW mining + sign |
+| `nostr_nip44_encrypt` / `nostr_nip44_decrypt` | NIP-44 encrypt/decrypt |
+| `nostr_nip04_encrypt` / `nostr_nip04_decrypt` | NIP-04 encrypt/decrypt |
 
 Example: `nsigner_client_call(client, "sign", "[\"68656c6c6f\",{\"algorithm\":\"ed25519\",\"index\":0}]", &result)`
 
 For secp256k1, the optional `scheme` parameter selects `"schnorr"` (default) or `"ecdsa"`.
 
-Old verbs (`sign_data`, `ssh_sign`, `verify_signature`, `kem_encapsulate`, `kem_decapsulate`) also accept the `algorithm` parameter and map to the new verbs. Without `algorithm`, they use the role-based path (backward compatible).
-
 ### `get_public_key` response format
 
-- **secp256k1 (backward compatible):** `result` is a plain hex string
-  (`cJSON_IsString(result)` is true, 64 hex chars).
-- **secp256k1 with `{"format":"structured"}` option:** `result` is a JSON
-  string containing `{"algorithm":"secp256k1","public_key":"<hex>","key_id":"<16 hex>"}`.
-- **All other algorithms:** `result` is always a JSON string containing
-  `{"algorithm":"<alg>","public_key":"<hex>","key_id":"<16 hex>"}`.
+The algorithm-based `get_public_key` always returns a structured JSON string:
+`{"algorithm":"<alg>","public_key":"<hex>","key_id":"<16 hex>"}`.
+
+The role-based `nostr_get_public_key` returns a plain 64-hex-char secp256k1
+public key by default, or the structured form with `{"format":"structured"}`.
 
 Clients should parse the `result` string with `cJSON_Parse` to extract the
-`algorithm`, `public_key`, and `key_id` fields for non-secp256k1 algorithms.
+`algorithm`, `public_key`, and `key_id` fields when the result is a JSON object.
 
 ### Key sizes
 

client/demo_c99.c

@@ -3,12 +3,12 @@
  * via Qubes qrexec and performing all three core operations:
  *
  *   1. get_public_key  — retrieve a Nostr public key by nostr_index
- *   2. sign_event      — sign a Nostr event (kind 1 text note)
- *   3. nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
+ *   2. nostr_sign_event      — sign a Nostr event (kind 1 text note)
+ *   3. nostr_nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
  *
- * Note: mine_event (NIP-13 PoW) is also available via the JSON-RPC interface.
- * See demo_javascript.js and demo_python.py for mine_event usage examples.
- * The high-level nostr_signer API does not yet wrap mine_event.
+ * Note: nostr_mine_event (NIP-13 PoW) is also available via the JSON-RPC interface.
+ * See demo_javascript.js and demo_python.py for nostr_mine_event usage examples.
+ * The high-level nostr_signer API does not yet wrap nostr_mine_event.
  *
  * This uses the high-level nostr_signer API from nostr_core_lib:
  *   - nostr_signer_nsigner_qrexec()     — qrexec transport (no network)
@@ -132,7 +132,7 @@ static int demo_sign_event(nostr_signer_t *signer, const char *pubkey_hex) {
     char *signed_json = NULL;
     int rc;
 
-    printf("\n=== Demo 2: sign_event (kind 1 text note) ===\n");
+    printf("\n=== Demo 2: nostr_sign_event (kind 1 text note) ===\n");
 
     /* Build an unsigned Nostr event (kind 1 text note) */
     unsigned_event = cJSON_CreateObject();
@@ -163,7 +163,7 @@ static int demo_sign_event(nostr_signer_t *signer, const char *pubkey_hex) {
     /* Sign it */
     rc = nostr_signer_sign_event(signer, unsigned_event, &signed_event);
     if (rc != NOSTR_SUCCESS) {
-        print_error("sign_event", rc);
+        print_error("nostr_nostr_sign_event", rc);
         cJSON_Delete(unsigned_event);
         return rc;
     }
@@ -204,14 +204,14 @@ static int demo_nip44(nostr_signer_t *signer, const char *pubkey_hex) {
     char *decrypted = NULL;
     int rc;
 
-    printf("\n=== Demo 3: nip44_encrypt / nip44_decrypt ===\n");
+    printf("\n=== Demo 3: nostr_nip44_encrypt / nostr_nip44_decrypt ===\n");
     printf("  plaintext:  \"%s\"\n", plaintext);
     printf("  peer pubkey: %s (self)\n", pubkey_hex);
 
     /* Encrypt */
     rc = nostr_signer_nip44_encrypt(signer, pubkey_hex, plaintext, &ciphertext);
     if (rc != NOSTR_SUCCESS) {
-        print_error("nip44_encrypt", rc);
+        print_error("nostr_nostr_nip44_encrypt", rc);
         return rc;
     }
 
@@ -220,7 +220,7 @@ static int demo_nip44(nostr_signer_t *signer, const char *pubkey_hex) {
     /* Decrypt (using our own pubkey as the sender) */
     rc = nostr_signer_nip44_decrypt(signer, pubkey_hex, ciphertext, &decrypted);
     if (rc != NOSTR_SUCCESS) {
-        print_error("nip44_decrypt", rc);
+        print_error("nostr_nostr_nip44_decrypt", rc);
         free(ciphertext);
         return rc;
     }

client/demo_javascript.js

@@ -4,8 +4,8 @@
  * running n_signer via Qubes qrexec and performing all three core operations:
  *
  *   1. get_public_key  — retrieve a Nostr public key by nostr_index
- *   2. sign_event      — sign a Nostr event (kind 1 text note)
- *   3. nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
+ *   2. nostr_sign_event      — sign a Nostr event (kind 1 text note)
+ *   3. nostr_nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
  *
  * Uses qrexec-client-vm (Qubes OS inter-qube IPC). No auth envelope needed —
  * identity comes from QREXEC_REMOTE_DOMAIN on the server side.
@@ -120,7 +120,7 @@ async function demoGetPublicKey(targetQube, nostrIndex) {
  * Demo 2: Sign a Nostr event (kind 1 text note).
  */
 async function demoSignEvent(targetQube, nostrIndex, pubkeyHex) {
-  console.log("\n=== Demo 2: sign_event (kind 1 text note) ===");
+  console.log("\n=== Demo 2: nostr_sign_event (kind 1 text note) ===");
 
   const unsignedEvent = {
     kind: 1,
@@ -135,12 +135,12 @@ async function demoSignEvent(targetQube, nostrIndex, pubkeyHex) {
 
   const response = await callNsigner(targetQube, {
     id: "2",
-    method: "sign_event",
+    method: "nostr_nostr_sign_event",
     params: [JSON.stringify(unsignedEvent), { nostr_index: nostrIndex }],
   });
 
   if (response.error) {
-    throw new Error(`sign_event failed: ${JSON.stringify(response.error)}`);
+    throw new Error(`nostr_sign_event failed: ${JSON.stringify(response.error)}`);
   }
 
   const signedEvent = JSON.parse(response.result);
@@ -159,19 +159,19 @@ async function demoSignEvent(targetQube, nostrIndex, pubkeyHex) {
 async function demoNip44(targetQube, nostrIndex, pubkeyHex) {
   const plaintext = "Secret message from n_signer JavaScript demo!";
 
-  console.log("\n=== Demo 3: nip44_encrypt / nip44_decrypt ===");
+  console.log("\n=== Demo 3: nostr_nip44_encrypt / nostr_nip44_decrypt ===");
   console.log(`  plaintext:  "${plaintext}"`);
   console.log(`  peer pubkey: ${pubkeyHex} (self)`);
 
   // Encrypt
   const encResponse = await callNsigner(targetQube, {
     id: "3",
-    method: "nip44_encrypt",
+    method: "nostr_nostr_nip44_encrypt",
     params: [pubkeyHex, plaintext, { nostr_index: nostrIndex }],
   });
 
   if (encResponse.error) {
-    throw new Error(`nip44_encrypt failed: ${JSON.stringify(encResponse.error)}`);
+    throw new Error(`nostr_nip44_encrypt failed: ${JSON.stringify(encResponse.error)}`);
   }
 
   const ciphertext = encResponse.result;
@@ -180,12 +180,12 @@ async function demoNip44(targetQube, nostrIndex, pubkeyHex) {
   // Decrypt
   const decResponse = await callNsigner(targetQube, {
     id: "4",
-    method: "nip44_decrypt",
+    method: "nostr_nostr_nip44_decrypt",
     params: [pubkeyHex, ciphertext, { nostr_index: nostrIndex }],
   });
 
   if (decResponse.error) {
-    throw new Error(`nip44_decrypt failed: ${JSON.stringify(decResponse.error)}`);
+    throw new Error(`nostr_nip44_decrypt failed: ${JSON.stringify(decResponse.error)}`);
   }
 
   const decrypted = decResponse.result;
@@ -199,7 +199,7 @@ async function demoNip44(targetQube, nostrIndex, pubkeyHex) {
 }
 
 async function demoMineEvent(targetQube, nostrIndex) {
-  console.log("\n--- Demo 4: mine_event (NIP-13 Proof-of-Work) ---");
+  console.log("\n--- Demo 4: nostr_mine_event (NIP-13 Proof-of-Work) ---");
 
   const event = {
     kind: 1,
@@ -210,7 +210,7 @@ async function demoMineEvent(targetQube, nostrIndex) {
   console.log("  Mining with difficulty=4, threads=4, timeout_sec=30...");
   const response = await callNsigner(targetQube, {
     id: "5",
-    method: "mine_event",
+    method: "nostr_nostr_mine_event",
     params: [JSON.stringify(event), {
       difficulty: 4,
       threads: 4,
@@ -220,7 +220,7 @@ async function demoMineEvent(targetQube, nostrIndex) {
   });
 
   if (response.error) {
-    throw new Error(`mine_event failed: ${JSON.stringify(response.error)}`);
+    throw new Error(`nostr_mine_event failed: ${JSON.stringify(response.error)}`);
   }
 
   const result = JSON.parse(response.result);

client/demo_python.py

@@ -4,8 +4,8 @@ demo_python.py — comprehensive Python demo for connecting to a running n_signe
 via Qubes qrexec and performing all three core operations:
 
   1. get_public_key  — retrieve a Nostr public key by nostr_index
-  2. sign_event      — sign a Nostr event (kind 1 text note)
-  3. nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
+  2. nostr_sign_event      — sign a Nostr event (kind 1 text note)
+  3. nostr_nip44_encrypt   — encrypt a message to a peer (and decrypt it back)
 
 Uses qrexec-client-vm (Qubes OS inter-qube IPC). No auth envelope needed —
 identity comes from QREXEC_REMOTE_DOMAIN on the server side.
@@ -148,7 +148,7 @@ def demo_get_public_key(target_qube, nostr_index):
 
 def demo_sign_event(target_qube, nostr_index, pubkey_hex):
     """Demo 2: Sign a Nostr event (kind 1 text note)."""
-    print("\n=== Demo 2: sign_event (kind 1 text note) ===")
+    print("\n=== Demo 2: nostr_sign_event (kind 1 text note) ===")
 
     unsigned_event = {
         "kind": 1,
@@ -165,13 +165,13 @@ def demo_sign_event(target_qube, nostr_index, pubkey_hex):
         target_qube,
         {
             "id": "2",
-            "method": "sign_event",
+            "method": "nostr_nostr_sign_event",
             "params": [json.dumps(unsigned_event, separators=(",", ":")), {"nostr_index": nostr_index}],
         },
     )
 
     if "error" in response:
-        raise RuntimeError(f"sign_event failed: {json.dumps(response['error'])}")
+        raise RuntimeError(f"nostr_sign_event failed: {json.dumps(response['error'])}")
 
     signed_event = json.loads(response["result"])
     print("  Signed event:")
@@ -185,7 +185,7 @@ def demo_nip44(target_qube, nostr_index, pubkey_hex):
     """Demo 3: NIP-44 encrypt and decrypt."""
     plaintext = "Secret message from n_signer Python demo!"
 
-    print("\n=== Demo 3: nip44_encrypt / nip44_decrypt ===")
+    print("\n=== Demo 3: nostr_nip44_encrypt / nostr_nip44_decrypt ===")
     print(f'  plaintext:  "{plaintext}"')
     print(f"  peer pubkey: {pubkey_hex} (self)")
 
@@ -194,13 +194,13 @@ def demo_nip44(target_qube, nostr_index, pubkey_hex):
         target_qube,
         {
             "id": "3",
-            "method": "nip44_encrypt",
+            "method": "nostr_nostr_nip44_encrypt",
             "params": [pubkey_hex, plaintext, {"nostr_index": nostr_index}],
         },
     )
 
     if "error" in enc_response:
-        raise RuntimeError(f"nip44_encrypt failed: {json.dumps(enc_response['error'])}")
+        raise RuntimeError(f"nostr_nip44_encrypt failed: {json.dumps(enc_response['error'])}")
 
     ciphertext = enc_response["result"]
     print(f"  ciphertext: {ciphertext}")
@@ -210,13 +210,13 @@ def demo_nip44(target_qube, nostr_index, pubkey_hex):
         target_qube,
         {
             "id": "4",
-            "method": "nip44_decrypt",
+            "method": "nostr_nostr_nip44_decrypt",
             "params": [pubkey_hex, ciphertext, {"nostr_index": nostr_index}],
         },
     )
 
     if "error" in dec_response:
-        raise RuntimeError(f"nip44_decrypt failed: {json.dumps(dec_response['error'])}")
+        raise RuntimeError(f"nostr_nip44_decrypt failed: {json.dumps(dec_response['error'])}")
 
     decrypted = dec_response["result"]
     print(f'  decrypted:  "{decrypted}"')
@@ -227,8 +227,8 @@ def demo_nip44(target_qube, nostr_index, pubkey_hex):
         raise RuntimeError("Round-trip FAILED: plaintext does not match decrypted")
 
 
-def demo_mine_event(target_qube, nostr_index):
-    print("\n--- Demo 4: mine_event (NIP-13 Proof-of-Work) ---")
+def demo_nostr_mine_event(target_qube, nostr_index):
+    print("\n--- Demo 4: nostr_mine_event (NIP-13 Proof-of-Work) ---")
 
     event = {"kind": 1, "content": "Hello Nostr with PoW!", "tags": []}
 
@@ -237,7 +237,7 @@ def demo_mine_event(target_qube, nostr_index):
         target_qube,
         {
             "id": "5",
-            "method": "mine_event",
+            "method": "nostr_nostr_mine_event",
             "params": [json.dumps(event), {
                 "difficulty": 4,
                 "threads": 4,
@@ -248,7 +248,7 @@ def demo_mine_event(target_qube, nostr_index):
     )
 
     if "error" in response:
-        raise RuntimeError(f"mine_event failed: {json.dumps(response['error'])}")
+        raise RuntimeError(f"nostr_mine_event failed: {json.dumps(response['error'])}")
 
     result = json.loads(response["result"])
     print(f"  achieved_difficulty: {result['achieved_difficulty']}")
@@ -282,7 +282,7 @@ def main():
         pubkey_hex = demo_get_public_key(target_qube, nostr_index)
         demo_sign_event(target_qube, nostr_index, pubkey_hex)
         demo_nip44(target_qube, nostr_index, pubkey_hex)
-        demo_mine_event(target_qube, nostr_index)
+        demo_nostr_mine_event(target_qube, nostr_index)
 
         print("\n=== Summary ===")
         print("All demos completed successfully.")

documents/CLIENT_IMPLEMENTATION.md

@@ -136,6 +136,7 @@ In addition to the role-based verbs above, the signer supports algorithm-based v
 - `encapsulate` — KEM encapsulation (params: `[peer_pubkey_hex, {algorithm}]`)
 - `decapsulate` — KEM decapsulation (params: `[ciphertext_hex, {algorithm, index}]`)
 - `derive_shared_secret` — ECDH key agreement (params: `[peer_pubkey_hex, {algorithm, index}]`)
+- `derive` — `HMAC-SHA256(privkey, data)` key-derived MAC (params: `[data, {algorithm:"secp256k1", index}]`; `index` required). Returns `{algorithm, key_id, digest}` where `digest` is 64 hex chars. Use for deterministic opaque identifiers (e.g. NIP-33 `d` tags) keyed by the derived private key.
 - `get_public_key` with `algorithm` parameter — returns structured JSON
 
 Algorithm names: `secp256k1`, `ed25519`, `ml-dsa-65`, `slh-dsa-128s`, `x25519`, `ml-kem-768`

documents/FIPS_DEPLOYMENT.md

@@ -61,13 +61,13 @@ Operational assumptions:
 Run `nsigner` in TCP listen mode:
 
 ```bash
-./build/nsigner --listen tcp:[::]:8080
+./build/nsigner --listen tcp:[::]:11111
 ```
 
 Or bind to a specific FIPS ULA address:
 
 ```bash
-./build/nsigner --listen tcp:[fd00::1234]:8080
+./build/nsigner --listen tcp:[fd00::1234]:11111
 ```
 
 Behavior notes:

examples/cyd_webserial_demo.html

@@ -0,0 +1,535 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+  <title>n_signer CYD Web Serial Demo</title>
+  <style>
+    :root {
+      --bg: #0b0f14;
+      --panel: #121821;
+      --panel-2: #182231;
+      --text: #e6edf3;
+      --muted: #9fb0c3;
+      --accent: #58a6ff;
+      --good: #3fb950;
+      --bad: #f85149;
+      --border: #263448;
+    }
+    * { box-sizing: border-box; }
+    body {
+      margin: 0;
+      font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
+      background: var(--bg);
+      color: var(--text);
+      line-height: 1.35;
+    }
+    .wrap { max-width: 980px; margin: 20px auto; padding: 0 14px 24px; }
+    h1 { margin: 0 0 8px; font-size: 1.45rem; }
+    p.note { margin: 0 0 14px; color: var(--muted); }
+    .row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
+    .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 12px; margin-top: 12px; }
+    .card { background: linear-gradient(180deg, var(--panel), var(--panel-2)); border: 1px solid var(--border); border-radius: 12px; padding: 12px; }
+    .card h2 { font-size: 1rem; margin: 0 0 10px; }
+    label { font-size: 0.86rem; color: var(--muted); display: block; margin: 6px 0 4px; }
+    input, textarea, select, button { font: inherit; border-radius: 8px; border: 1px solid var(--border); }
+    input, textarea, select { width: 100%; background: #0c131d; color: var(--text); padding: 8px 10px; }
+    textarea { min-height: 64px; resize: vertical; }
+    input[type="number"] { max-width: 130px; }
+    button { background: #1f6feb; color: white; padding: 8px 12px; cursor: pointer; border: 0; }
+    button[disabled] { opacity: 0.55; cursor: not-allowed; }
+    .secondary { background: #334155; }
+    .status { padding: 6px 10px; border-radius: 999px; background: #2a3648; color: var(--muted); font-size: 0.85rem; border: 1px solid var(--border); }
+    .status.ok { color: var(--good); border-color: #2f5a3a; }
+    .status.err { color: var(--bad); border-color: #6a3131; }
+    pre { margin: 8px 0 0; background: #0a1018; border: 1px solid #1b2636; color: #d7e2ee; padding: 10px; border-radius: 8px; overflow: auto; max-height: 200px; font-size: 12px; }
+    .mono { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
+    .warn { color: #d29922; font-size: 0.8rem; }
+  </style>
+</head>
+<body>
+  <div class="wrap">
+    <h1>n_signer CYD Web Serial Demo</h1>
+    <p class="note">Connect to the CYD (CH340 serial) via Web Serial, then exercise every algorithm and verb in the n_signer API. Chrome/Edge/Brave/Opera only.</p>
+
+    <div class="card">
+      <div class="row">
+        <button id="connectBtn">Connect Web Serial</button>
+        <button id="disconnectBtn" class="secondary" disabled>Disconnect</button>
+        <span id="connStatus" class="status">Disconnected</span>
+      </div>
+      <pre id="log" class="mono"></pre>
+    </div>
+
+    <div class="grid">
+      <!-- Get Public Key (algorithm-based) -->
+      <section class="card">
+        <h2>Get Public Key (algorithm)</h2>
+        <label for="gpkAlg">Algorithm</label>
+        <select id="gpkAlg">
+          <option>secp256k1</option><option>ed25519</option><option>x25519</option>
+          <option>ml-dsa-65</option><option>slh-dsa-128s</option><option>ml-kem-768</option>
+        </select>
+        <label for="gpkIdx">Index</label>
+        <input id="gpkIdx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="gpkBtn" disabled>get_public_key</button>
+        </div>
+        <pre id="gpkOut" class="mono"></pre>
+      </section>
+
+      <!-- Nostr Get Public Key -->
+      <section class="card">
+        <h2>nostr_get_public_key</h2>
+        <label for="ngpkIdx">nostr_index</label>
+        <input id="ngpkIdx" type="number" value="0" min="0" />
+        <label for="ngpkFmt">format</label>
+        <select id="ngpkFmt"><option>bare</option><option>structured</option></select>
+        <div class="row" style="margin-top:10px">
+          <button id="ngpkBtn" disabled>nostr_get_public_key</button>
+        </div>
+        <pre id="ngpkOut" class="mono"></pre>
+      </section>
+
+      <!-- Sign / Verify -->
+      <section class="card">
+        <h2>sign / verify</h2>
+        <label for="signAlg">Algorithm</label>
+        <select id="signAlg">
+          <option>secp256k1</option><option>ed25519</option><option>ml-dsa-65</option><option>slh-dsa-128s</option>
+        </select>
+        <label for="signIdx">Index</label>
+        <input id="signIdx" type="number" value="0" min="0" />
+        <label for="signScheme">scheme (secp256k1 only)</label>
+        <select id="signScheme"><option>schnorr</option><option>ecdsa</option></select>
+        <label for="signMsg">message (hex)</label>
+        <input id="signMsg" value="68656c6c6f" />
+        <div class="row" style="margin-top:10px">
+          <button id="signBtn" disabled>sign</button>
+          <button id="verifyBtn" disabled>verify</button>
+        </div>
+        <pre id="signOut" class="mono"></pre>
+      </section>
+
+      <!-- KEM encapsulate / decapsulate -->
+      <section class="card">
+        <h2>encapsulate / decapsulate (ml-kem-768)</h2>
+        <label for="kemPeer">peer pubkey hex (1184 bytes / 2368 hex) — leave empty to use self pubkey</label>
+        <textarea id="kemPeer" placeholder="auto: uses ml-kem-768 get_public_key"></textarea>
+        <label for="kemIdx">index (for decapsulate)</label>
+        <input id="kemIdx" type="number" value="0" min="0" />
+        <label for="kemCt">ciphertext hex (for decapsulate)</label>
+        <textarea id="kemCt" placeholder="filled by encapsulate"></textarea>
+        <div class="row" style="margin-top:10px">
+          <button id="encapBtn" disabled>encapsulate</button>
+          <button id="decapBtn" disabled>decapsulate</button>
+        </div>
+        <pre id="kemOut" class="mono"></pre>
+      </section>
+
+      <!-- derive_shared_secret (x25519) -->
+      <section class="card">
+        <h2>derive_shared_secret (x25519)</h2>
+        <label for="x25519Peer">peer pubkey hex (32 bytes / 64 hex)</label>
+        <input id="x25519Peer" placeholder="64 hex chars" />
+        <label for="x25519Idx">index</label>
+        <input id="x25519Idx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="x25519Btn" disabled>derive_shared_secret</button>
+        </div>
+        <pre id="x25519Out" class="mono"></pre>
+      </section>
+
+      <!-- derive (HMAC) -->
+      <section class="card">
+        <h2>derive (secp256k1 HMAC-SHA256)</h2>
+        <label for="deriveData">data (UTF-8 string)</label>
+        <input id="deriveData" value="hello-derive" />
+        <label for="deriveIdx">index (required)</label>
+        <input id="deriveIdx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="deriveBtn" disabled>derive</button>
+        </div>
+        <pre id="deriveOut" class="mono"></pre>
+      </section>
+
+      <!-- Nostr Sign Event -->
+      <section class="card">
+        <h2>nostr_sign_event</h2>
+        <label for="nseContent">content</label>
+        <textarea id="nseContent">hello from cyd webserial demo</textarea>
+        <label for="nseIdx">nostr_index</label>
+        <input id="nseIdx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="nseBtn" disabled>nostr_sign_event</button>
+        </div>
+        <pre id="nseOut" class="mono"></pre>
+      </section>
+
+      <!-- Nostr Mine Event -->
+      <section class="card">
+        <h2>nostr_mine_event</h2>
+        <p class="warn">Slow on ESP32 — uses single-threaded PoW. Keep difficulty low.</p>
+        <label for="nmeContent">content</label>
+        <textarea id="nmeContent">mined by cyd</textarea>
+        <label for="nmeIdx">nostr_index</label>
+        <input id="nmeIdx" type="number" value="0" min="0" />
+        <label for="nmeDiff">difficulty (leading zero bits)</label>
+        <input id="nmeDiff" type="number" value="4" min="1" max="16" />
+        <label for="nmeTimeout">timeout (sec)</label>
+        <input id="nmeTimeout" type="number" value="30" min="1" max="60" />
+        <div class="row" style="margin-top:10px">
+          <button id="nmeBtn" disabled>nostr_mine_event</button>
+        </div>
+        <pre id="nmeOut" class="mono"></pre>
+      </section>
+
+      <!-- NIP-04 -->
+      <section class="card">
+        <h2>nostr_nip04_encrypt / decrypt</h2>
+        <label for="nip04Peer">peer pubkey hex (32-byte x-only)</label>
+        <input id="nip04Peer" placeholder="64 hex chars" />
+        <label for="nip04Msg">plaintext</label>
+        <textarea id="nip04Msg">hello via nip04</textarea>
+        <label for="nip04Cipher">ciphertext (for decrypt)</label>
+        <textarea id="nip04Cipher" placeholder="ciphertext?iv=..."></textarea>
+        <label for="nip04Idx">nostr_index</label>
+        <input id="nip04Idx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="nip04EncBtn" disabled>encrypt</button>
+          <button id="nip04DecBtn" disabled>decrypt</button>
+        </div>
+        <pre id="nip04Out" class="mono"></pre>
+      </section>
+
+      <!-- NIP-44 -->
+      <section class="card">
+        <h2>nostr_nip44_encrypt / decrypt</h2>
+        <label for="nip44Peer">peer pubkey hex (32-byte x-only)</label>
+        <input id="nip44Peer" placeholder="64 hex chars" />
+        <label for="nip44Msg">plaintext</label>
+        <textarea id="nip44Msg">hello via nip44</textarea>
+        <label for="nip44Cipher">ciphertext (for decrypt)</label>
+        <textarea id="nip44Cipher" placeholder="base64 payload"></textarea>
+        <label for="nip44Idx">nostr_index</label>
+        <input id="nip44Idx" type="number" value="0" min="0" />
+        <div class="row" style="margin-top:10px">
+          <button id="nip44EncBtn" disabled>encrypt</button>
+          <button id="nip44DecBtn" disabled>decrypt</button>
+        </div>
+        <pre id="nip44Out" class="mono"></pre>
+      </section>
+
+      <!-- OTP encrypt / decrypt -->
+      <section class="card">
+        <h2>encrypt / decrypt (otp)</h2>
+        <p class="note">OTP pad is derived from the mnemonic on the CYD. Offset advances monotonically.</p>
+        <label for="otpPlain">plaintext (base64)</label>
+        <textarea id="otpPlain">SGVsbG8sIE9UUCB3b3JsZCE=</textarea>
+        <label for="otpCipher">ciphertext (for decrypt, base64)</label>
+        <textarea id="otpCipher" placeholder="filled by encrypt"></textarea>
+        <label for="otpEnc">encoding</label>
+        <select id="otpEnc"><option>ascii</option><option>binary</option></select>
+        <div class="row" style="margin-top:10px">
+          <button id="otpEncBtn" disabled>encrypt</button>
+          <button id="otpDecBtn" disabled>decrypt</button>
+        </div>
+        <pre id="otpOut" class="mono"></pre>
+      </section>
+    </div>
+  </div>
+
+  <script type="module">
+    import { schnorr } from "https://esm.sh/@noble/curves@1.5.0/secp256k1?bundle";
+
+    const logEl = document.getElementById("log");
+    const connStatusEl = document.getElementById("connStatus");
+    const connectBtn = document.getElementById("connectBtn");
+    const disconnectBtn = document.getElementById("disconnectBtn");
+
+    let port = null;
+    let reader = null;
+    let writer = null;
+    let readLoopRunning = false;
+    let rxBuffer = new Uint8Array(0);
+    let pendingResolve = null;
+
+    function log(...args) {
+      logEl.textContent += args.join(" ") + "\n";
+      logEl.scrollTop = logEl.scrollHeight;
+    }
+    function setStatus(text, mode = "") {
+      connStatusEl.textContent = text;
+      connStatusEl.className = `status ${mode}`.trim();
+    }
+    function hex(bytes) {
+      return Array.from(bytes).map(b => b.toString(16).padStart(2, "0")).join("");
+    }
+    function utf8(s) { return new TextEncoder().encode(s); }
+    function be32(n) {
+      return new Uint8Array([(n >>> 24) & 0xff, (n >>> 16) & 0xff, (n >>> 8) & 0xff, n & 0xff]);
+    }
+    async function sha256Hex(dataBytes) {
+      const h = await crypto.subtle.digest("SHA-256", dataBytes);
+      return hex(new Uint8Array(h));
+    }
+    function pretty(value) {
+      try { return JSON.stringify(value, null, 2); } catch { return String(value); }
+    }
+
+    async function buildAuth(method, params) {
+      const callerPriv = Uint8Array.from({ length: 32 }, (_, i) => i + 1);
+      const callerPubX = hex(schnorr.getPublicKey(callerPriv));
+      const createdAt = Math.floor(Date.now() / 1000);
+      const paramsJson = JSON.stringify(params);
+      const bodyHash = await sha256Hex(utf8(paramsJson));
+      const tags = [
+        ["nsigner_rpc", "1"],
+        ["nsigner_method", method],
+        ["nsigner_body_hash", bodyHash],
+      ];
+      const content = "cyd-webserial-demo";
+      const ser = JSON.stringify([0, callerPubX, createdAt, 27235, tags, content]);
+      const id = await sha256Hex(utf8(ser));
+      const sigBytes = await schnorr.sign(id, callerPriv, new Uint8Array(32));
+      const sigHex = typeof sigBytes === "string" ? sigBytes : hex(sigBytes);
+      return { id, pubkey: callerPubX, created_at: createdAt, kind: 27235, tags, content, sig: sigHex };
+    }
+
+    /* ---- Web Serial transport ---- */
+    async function readLoop() {
+      readLoopRunning = true;
+      while (readLoopRunning && reader) {
+        try {
+          const { value, done } = await reader.read();
+          if (done) break;
+          if (value) {
+            const next = new Uint8Array(rxBuffer.length + value.length);
+            next.set(rxBuffer, 0);
+            next.set(value, rxBuffer.length);
+            rxBuffer = next;
+            tryDeliver();
+          }
+        } catch (e) {
+          log("read error:", e.message);
+          break;
+        }
+      }
+      readLoopRunning = false;
+    }
+
+    function tryDeliver() {
+      if (pendingResolve === null) return;
+      while (rxBuffer.length >= 4) {
+        const len = (rxBuffer[0] << 24) | (rxBuffer[1] << 16) | (rxBuffer[2] << 8) | rxBuffer[3];
+        if (len <= 0 || len > 16384) {
+          /* resync: drop one byte */
+          rxBuffer = rxBuffer.slice(1);
+          continue;
+        }
+        if (rxBuffer.length < 4 + len) return;
+        const payload = rxBuffer.slice(4, 4 + len);
+        rxBuffer = rxBuffer.slice(4 + len);
+        const text = new TextDecoder().decode(payload);
+        let parsed;
+        try { parsed = JSON.parse(text); } catch { parsed = text; }
+        const r = pendingResolve;
+        pendingResolve = null;
+        r(parsed);
+        if (pendingResolve === null) return;
+      }
+    }
+
+    async function sendRpc(reqObj) {
+      if (!writer) throw new Error("not connected");
+      const body = utf8(JSON.stringify(reqObj));
+      const frame = new Uint8Array(4 + body.length);
+      frame.set(be32(body.length), 0);
+      frame.set(body, 4);
+      await writer.write(frame);
+      const resp = await new Promise((resolve, reject) => {
+        pendingResolve = resolve;
+        setTimeout(() => {
+          if (pendingResolve === resolve) {
+            pendingResolve = null;
+            reject(new Error("timeout (30s) — check the CYD screen for an approval prompt"));
+          }
+        }, 65000);
+      });
+      return resp;
+    }
+
+    async function callVerb(method, params, outEl) {
+      outEl.textContent = "→ " + method + " " + JSON.stringify(params);
+      try {
+        const auth = await buildAuth(method, params);
+        const req = { id: String(Math.floor(Math.random() * 1e9)), method, params, auth };
+        const resp = await sendRpc(req);
+        outEl.textContent += "\n← " + pretty(resp);
+      } catch (e) {
+        outEl.textContent += "\n✗ " + e.message;
+      }
+    }
+
+    /* ---- Connect / Disconnect ---- */
+    connectBtn.addEventListener("click", async () => {
+      try {
+        port = await navigator.serial.requestPort();
+        await port.open({ baudRate: 115200 });
+        reader = port.readable.getReader();
+        writer = port.writable.getWriter();
+        rxBuffer = new Uint8Array(0);
+        readLoop();
+        setStatus("Connected", "ok");
+        log("Connected to CYD via Web Serial @ 115200 baud");
+        document.querySelectorAll("button[id$='Btn']").forEach(b => {
+          if (b !== connectBtn && b !== disconnectBtn) b.disabled = false;
+        });
+        disconnectBtn.disabled = false;
+        connectBtn.disabled = true;
+      } catch (e) {
+        setStatus("Error", "err");
+        log("connect failed:", e.message);
+      }
+    });
+
+    disconnectBtn.addEventListener("click", async () => {
+      readLoopRunning = false;
+      try { if (reader) await reader.cancel(); } catch {}
+      try { if (writer) await writer.releaseLock(); } catch {}
+      try { if (port) await port.close(); } catch {}
+      reader = null; writer = null; port = null;
+      setStatus("Disconnected");
+      document.querySelectorAll("button[id$='Btn']").forEach(b => {
+        if (b !== connectBtn) b.disabled = true;
+      });
+      connectBtn.disabled = false;
+      disconnectBtn.disabled = true;
+      log("Disconnected");
+    });
+
+    /* ---- Verb wiring ---- */
+    const $ = id => document.getElementById(id);
+
+    $("gpkBtn").addEventListener("click", () => {
+      const alg = $("gpkAlg").value, idx = Number($("gpkIdx").value || 0);
+      callVerb("get_public_key", [{ algorithm: alg, index: idx }], $("gpkOut"));
+    });
+    $("ngpkBtn").addEventListener("click", () => {
+      const idx = Number($("ngpkIdx").value || 0), fmt = $("ngpkFmt").value;
+      const opts = { nostr_index: idx };
+      if (fmt === "structured") opts.format = "structured";
+      callVerb("nostr_get_public_key", [opts], $("ngpkOut"));
+    });
+
+    $("signBtn").addEventListener("click", () => {
+      const alg = $("signAlg").value, idx = Number($("signIdx").value || 0);
+      const scheme = $("signScheme").value, msg = $("signMsg").value;
+      const opts = { algorithm: alg, index: idx };
+      if (alg === "secp256k1") opts.scheme = scheme;
+      callVerb("sign", [msg, opts], $("signOut"));
+    });
+    $("verifyBtn").addEventListener("click", async () => {
+      const alg = $("signAlg").value, idx = Number($("signIdx").value || 0);
+      const scheme = $("signScheme").value, msg = $("signMsg").value;
+      const opts = { algorithm: alg, index: idx };
+      if (alg === "secp256k1") opts.scheme = scheme;
+      /* parse the last sign result to get the signature */
+      const outText = $("signOut").textContent;
+      const m = outText.match(/"signature"\s*:\s*"([0-9a-f]+)"/);
+      if (!m) { $("signOut").textContent += "\n✗ no signature found — run sign first"; return; }
+      callVerb("verify", [msg, m[1], opts], $("signOut"));
+    });
+
+    $("encapBtn").addEventListener("click", async () => {
+      let peer = $("kemPeer").value.trim();
+      if (!peer) {
+        /* fetch self ml-kem-768 pubkey first */
+        const opts = [{ algorithm: "ml-kem-768", index: Number($("kemIdx").value || 0) }];
+        const auth = await buildAuth("get_public_key", opts);
+        const resp = await sendRpc({ id: String(Math.floor(Math.random()*1e9)), method: "get_public_key", params: opts, auth });
+        peer = resp.result && JSON.parse(resp.result).public_key;
+        if (!peer) { $("kemOut").textContent = "✗ could not fetch self pubkey"; return; }
+        $("kemPeer").value = peer;
+      }
+      callVerb("encapsulate", [peer, { algorithm: "ml-kem-768" }], $("kemOut"));
+    });
+    $("decapBtn").addEventListener("click", () => {
+      const ct = $("kemCt").value.trim();
+      const idx = Number($("kemIdx").value || 0);
+      if (!ct) { $("kemOut").textContent = "✗ paste a ciphertext first (from encapsulate)"; return; }
+      callVerb("decapsulate", [ct, { algorithm: "ml-kem-768", index: idx }], $("kemOut"));
+    });
+
+    $("x25519Btn").addEventListener("click", () => {
+      const peer = $("x25519Peer").value.trim();
+      const idx = Number($("x25519Idx").value || 0);
+      if (!peer) { $("x25519Out").textContent = "✗ enter peer pubkey"; return; }
+      callVerb("derive_shared_secret", [peer, { algorithm: "x25519", index: idx }], $("x25519Out"));
+    });
+
+    $("deriveBtn").addEventListener("click", () => {
+      const data = $("deriveData").value;
+      const idx = Number($("deriveIdx").value || 0);
+      callVerb("derive", [data, { algorithm: "secp256k1", index: idx }], $("deriveOut"));
+    });
+
+    $("nseBtn").addEventListener("click", () => {
+      const content = $("nseContent").value;
+      const idx = Number($("nseIdx").value || 0);
+      const event = { kind: 1, created_at: Math.floor(Date.now()/1000), tags: [], content };
+      callVerb("nostr_sign_event", [event, { nostr_index: idx }], $("nseOut"));
+    });
+
+    $("nmeBtn").addEventListener("click", () => {
+      const content = $("nmeContent").value;
+      const idx = Number($("nmeIdx").value || 0);
+      const diff = Number($("nmeDiff").value || 4);
+      const timeout = Number($("nmeTimeout").value || 30);
+      const event = { kind: 1, created_at: Math.floor(Date.now()/1000), tags: [], content };
+      callVerb("nostr_mine_event", [event, { nostr_index: idx, difficulty: diff, timeout_sec: timeout }], $("nmeOut"));
+    });
+
+    const nip04Enc = () => {
+      const peer = $("nip04Peer").value.trim(), msg = $("nip04Msg").value, idx = Number($("nip04Idx").value || 0);
+      if (!peer) { $("nip04Out").textContent = "✗ enter peer pubkey"; return; }
+      callVerb("nostr_nip04_encrypt", [peer, msg, { nostr_index: idx }], $("nip04Out"));
+    };
+    const nip04Dec = () => {
+      const peer = $("nip04Peer").value.trim(), ct = $("nip04Cipher").value, idx = Number($("nip04Idx").value || 0);
+      if (!peer || !ct) { $("nip04Out").textContent = "✗ enter peer pubkey + ciphertext"; return; }
+      callVerb("nostr_nip04_decrypt", [peer, ct, { nostr_index: idx }], $("nip04Out"));
+    };
+    $("nip04EncBtn").addEventListener("click", nip04Enc);
+    $("nip04DecBtn").addEventListener("click", nip04Dec);
+
+    const nip44Enc = () => {
+      const peer = $("nip44Peer").value.trim(), msg = $("nip44Msg").value, idx = Number($("nip44Idx").value || 0);
+      if (!peer) { $("nip44Out").textContent = "✗ enter peer pubkey"; return; }
+      callVerb("nostr_nip44_encrypt", [peer, msg, { nostr_index: idx }], $("nip44Out"));
+    };
+    const nip44Dec = () => {
+      const peer = $("nip44Peer").value.trim(), ct = $("nip44Cipher").value, idx = Number($("nip44Idx").value || 0);
+      if (!peer || !ct) { $("nip44Out").textContent = "✗ enter peer pubkey + ciphertext"; return; }
+      callVerb("nostr_nip44_decrypt", [peer, ct, { nostr_index: idx }], $("nip44Out"));
+    };
+    $("nip44EncBtn").addEventListener("click", nip44Enc);
+    $("nip44DecBtn").addEventListener("click", nip44Dec);
+
+    $("otpEncBtn").addEventListener("click", () => {
+      const pt = $("otpPlain").value, enc = $("otpEnc").value;
+      callVerb("encrypt", [pt, { algorithm: "otp", encoding: enc }], $("otpOut"));
+    });
+    $("otpDecBtn").addEventListener("click", () => {
+      const ct = $("otpCipher").value, enc = $("otpEnc").value;
+      if (!ct) { $("otpOut").textContent = "✗ paste ciphertext first (from encrypt)"; return; }
+      callVerb("decrypt", [ct, { algorithm: "otp", encoding: enc }], $("otpOut"));
+    });
+
+    if (!("serial" in navigator)) {
+      log("Web Serial not supported in this browser. Use Chrome/Edge/Brave/Opera.");
+      connectBtn.disabled = true;
+    }
+  </script>
+</body>
+</html>

examples/feather_sign_event.py

@@ -140,11 +140,11 @@ def main() -> int:
     req = {
         "jsonrpc": "2.0",
         "id": "2",
-        "method": "sign_event",
+        "method": "nostr_sign_event",
         "params": params,
     }
     if not no_auth:
-        req["auth"] = build_auth_envelope("sign_event", params, caller_priv)
+        req["auth"] = build_auth_envelope("nostr_sign_event", params, caller_priv)
 
     body = json.dumps(req, separators=(",", ":")).encode("utf-8")
     frame = struct.pack(">I", len(body)) + body

examples/feather_webusb_demo.html

@@ -460,7 +460,7 @@
         };
 
         const params = [unsignedEvent, getIndexOptions()];
-        const resp = await rpcCall("sign_event", params, "web-sign-kind1");
+        const resp = await rpcCall("nostr_sign_event", params, "web-sign-kind1");
         signOutEl.textContent = pretty(resp?.result ?? resp);
       } catch (e) {
         signOutEl.textContent = String(e);
@@ -472,7 +472,7 @@
         const peer = requirePeerHex(nip04PeerEl.value);
         const msg = String(nip04MsgEl.value || "");
         const params = [peer, msg, getIndexOptions()];
-        const resp = await rpcCall("nip04_encrypt", params, "web-nip04-enc");
+        const resp = await rpcCall("nostr_nip04_encrypt", params, "web-nip04-enc");
         nip04OutEl.textContent = pretty(resp?.result ?? resp);
         if (resp && typeof resp.result === "string") {
           nip04DecPeerEl.value = peer;
@@ -488,7 +488,7 @@
         const peer = requirePeerHex(nip04DecPeerEl.value);
         const ciphertext = String(nip04CipherEl.value || "");
         const params = [peer, ciphertext, getIndexOptions()];
-        const resp = await rpcCall("nip04_decrypt", params, "web-nip04-dec");
+        const resp = await rpcCall("nostr_nip04_decrypt", params, "web-nip04-dec");
         nip04DecOutEl.textContent = requireStringResult(resp, "NIP-04 decrypt");
       } catch (e) {
         nip04DecOutEl.textContent = String(e);
@@ -500,7 +500,7 @@
         const peer = requirePeerHex(nip44PeerEl.value);
         const msg = String(nip44MsgEl.value || "");
         const params = [peer, msg, getIndexOptions()];
-        const resp = await rpcCall("nip44_encrypt", params, "web-nip44-enc");
+        const resp = await rpcCall("nostr_nip44_encrypt", params, "web-nip44-enc");
         nip44OutEl.textContent = pretty(resp?.result ?? resp);
         if (resp && typeof resp.result === "string") {
           nip44DecPeerEl.value = peer;
@@ -516,7 +516,7 @@
         const peer = requirePeerHex(nip44DecPeerEl.value);
         const ciphertext = String(nip44CipherEl.value || "");
         const params = [peer, ciphertext, getIndexOptions()];
-        const resp = await rpcCall("nip44_decrypt", params, "web-nip44-dec");
+        const resp = await rpcCall("nostr_nip44_decrypt", params, "web-nip44-dec");
         nip44DecOutEl.textContent = requireStringResult(resp, "NIP-44 decrypt");
       } catch (e) {
         nip44DecOutEl.textContent = String(e);

examples/get_pubkey_fips.py

@@ -8,7 +8,7 @@ import time
 from coincurve import PrivateKey
 
 HOST = "npub15uqyclnr3er7r8uhka7f0ae2yt4gkjat8gxdan04q0e6xrnwmtjswcyla3.fips"
-PORT = 8080
+PORT = 11111
 
 # Demo caller key (32 bytes). Replace with your stable caller key in real use.
 PRIVKEY = bytes(range(1, 33))

examples/get_pubkey_tcp.c

@@ -4,14 +4,14 @@
  * bech32 npub for each.
  *
  * This is a cross-qube test client for Qubes OS: the signer runs in the
- * nostr_signer qube listening on tcp:[::]:8080, and this client runs in
+ * nostr_signer qube listening on tcp:[::]:11111, and this client runs in
  * a different qube connecting to the signer's FIPS address.
  *
  * Usage:
  *   ./get_pubkey_tcp <host> <port>
- *   ./get_pubkey_tcp npub1xxx...fips 8080
+ *   ./get_pubkey_tcp npub1xxx...fips 11111
  *
- * If no arguments are given, defaults to localhost:8080.
+ * If no arguments are given, defaults to localhost:11111.
  *
  * Output: for each index, prints:
  *   index 0: hex=<64 hex chars>  npub=npub1...
@@ -95,7 +95,7 @@ static int query_pubkey(const char *host, int port, int nostr_index,
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
-    if (nsigner_client_call(client, "get_public_key", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "nostr_get_public_key", params, &result) != NOSTR_SUCCESS) {
         fprintf(stderr, "request failed for index %d: %s\n", nostr_index,
                 nsigner_client_last_error(client));
         params = NULL; /* nsigner_client_call took ownership even on failure */
@@ -139,7 +139,7 @@ cleanup:
 
 int main(int argc, char **argv) {
     const char *host = "127.0.0.1";
-    int port = 8080;
+    int port = 11111;
     char hex0[65], npub0[128];
     char hex1[65], npub1[128];
     int failures = 0;

examples/get_public_key_client.c

@@ -59,7 +59,7 @@ int main(int argc, char **argv) {
         goto cleanup;
     }
 
-    if (nsigner_client_call(client, "get_public_key", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "nostr_get_public_key", params, &result) != NOSTR_SUCCESS) {
         fprintf(stderr, "request failed: %s\n", nsigner_client_last_error(client));
         goto cleanup;
     }

examples/kb2040_hidden_signer_client.py

@@ -167,7 +167,7 @@ def cmd_get_public_key(args):
 
 def cmd_sign_event(args):
     event = json.loads(args.event)
-    print(json.dumps(rpc(args, "sign_event", {"event": event}), indent=2))
+    print(json.dumps(rpc(args, "nostr_sign_event", {"event": event}), indent=2))
 
 
 def build_parser():

examples/n_signer_qube_example_fips.js

@@ -5,14 +5,14 @@
  * and bech32 npub for each.
  *
  * This is a cross-qube test client for Qubes OS: the signer runs in the
- * nostr_signer qube listening on tcp:[::]:8080, and this client runs in
+ * nostr_signer qube listening on tcp:[::]:11111, and this client runs in
  * a different qube connecting to the signer's FIPS address.
  *
  * Usage:
  *   node n_signer_qube_example.js [host] [port]
- *   node n_signer_qube_example.js fd56:d7c3:f605:719d:15b:18a0:fb06:982f 8080
+ *   node n_signer_qube_example.js fd56:d7c3:f605:719d:15b:18a0:fb06:982f 11111
  *
- * If no arguments are given, defaults to localhost:8080.
+ * If no arguments are given, defaults to localhost:11111.
  *
  * Protocol:
  *   - 4-byte big-endian length prefix + JSON payload (TCP framing)
@@ -214,7 +214,7 @@ function hexToNpub(pubkeyHex) {
 
 async function main() {
   const host = process.argv[2] || "127.0.0.1";
-  const port = parseInt(process.argv[3] || "8080", 10);
+  const port = parseInt(process.argv[3] || "11111", 10);
 
   console.log(`Connecting to n_signer at ${host}:${port}`);
   console.log("Querying get_public_key for nostr_index 0 and 1...\n");

examples/otp_nostr_30078.py

@@ -0,0 +1,219 @@
+#!/usr/bin/env python3
+"""
+otp_nostr_30078.py — example: encrypt data with OTP, wrap in a Nostr kind 30078
+event, sign it with n_signer, and print the signed event for publishing.
+
+Workflow:
+  1. Call n_signer's `otp_encrypt` verb to encrypt plaintext with the bound OTP pad.
+  2. Build a Nostr kind 30078 (replaceable parameterized) event with the ASCII-armored
+     ciphertext as the `content` field.
+  3. Call n_signer's `sign_event` verb to sign the event with the secp256k1 key.
+  4. Print the signed event JSON, ready to publish to Nostr relays.
+
+This is a demo — it does not actually publish to a relay. To publish, send the
+signed event to your preferred Nostr relay using a library like nostr-tools,
+nostril, or nak.
+
+Usage:
+  python3 examples/otp_nostr_30078.py "Your secret message here"
+
+Requirements:
+  - n_signer running with --otp-pad-dir / --otp-pad bound, and a secp256k1
+    role (e.g. "main") available for sign_event.
+  - This script connects to n_signer via stdio (one process per request).
+
+See plans/otp_nostr_integration.md for the full design.
+"""
+import base64
+import hashlib
+import json
+import os
+import struct
+import subprocess
+import sys
+import time
+
+NSIGNER = "./build/nsigner"
+PAD_DIR = "/media/user/Music/pads"
+PAD_SPEC = "333e9902db839d9d"
+MNEMONIC_FILE = ".test_mnemonic"
+MNEMONIC_TMP = ".test_mnemonic_otp_30078.tmp"
+
+
+def send_framed(proc, obj):
+    payload = json.dumps(obj).encode()
+    proc.stdin.write(struct.pack(">I", len(payload)))
+    proc.stdin.write(payload)
+    proc.stdin.flush()
+
+
+def recv_framed(proc):
+    """Read a framed response, skipping any banner text on stdout."""
+    buf = b""
+    while True:
+        b = proc.stdout.read(1)
+        if not b:
+            return None
+        buf = (buf + b)[-4:]
+        if len(buf) < 4:
+            continue
+        (length,) = struct.unpack(">I", buf)
+        if 1 <= length <= 1024 * 1024:
+            peek = proc.stdout.read(1)
+            if peek == b"{":
+                body = peek + proc.stdout.read(length - 1)
+                return json.loads(body.decode())
+            else:
+                buf = (buf + peek)[-4:]
+
+
+def run_one_request(req_obj):
+    """Run nsigner in stdio mode for a single framed request/response."""
+    shell_cmd = (
+        f"exec 3<{MNEMONIC_TMP}; "
+        f"exec {NSIGNER} --listen stdio --mnemonic-fd 3 "
+        f"--otp-pad-dir {PAD_DIR} --otp-pad {PAD_SPEC} "
+        f"--otp-allow-blkback --allow-all"
+    )
+    proc = subprocess.Popen(
+        ["bash", "-c", shell_cmd],
+        stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+    )
+    import time as _time
+    _time.sleep(1.0)
+    if proc.poll() is not None:
+        err = proc.stderr.read().decode()
+        print(f"ERROR: nsigner exited early (code {proc.returncode})")
+        print(f"stderr: {err}")
+        return None
+    send_framed(proc, req_obj)
+    resp = recv_framed(proc)
+    proc.stdin.close()
+    try:
+        proc.wait(timeout=5)
+    except subprocess.TimeoutExpired:
+        proc.kill()
+    return resp
+
+
+def compute_event_id(event):
+    """Compute the Nostr event ID (SHA-256 of the canonical serialized event)."""
+    # Nostr event serialization: [0, pubkey, created_at, kind, tags, content]
+    serialized = json.dumps([
+        0,
+        event["pubkey"],
+        event["created_at"],
+        event["kind"],
+        event["tags"],
+        event["content"],
+    ], separators=(",", ":"), ensure_ascii=False)
+    return hashlib.sha256(serialized.encode()).hexdigest()
+
+
+def main():
+    plaintext = " ".join(sys.argv[1:]) if len(sys.argv) > 1 else "Secret OTP message"
+    print(f"Plaintext: {plaintext}")
+
+    # Prepare the mnemonic temp file.
+    with open(MNEMONIC_FILE) as f:
+        mnemonic = f.read().strip()
+    with open(MNEMONIC_TMP, "w") as f:
+        f.write(mnemonic + "\n")
+
+    try:
+        # Step 1: Get the public key for the "main" role
+        print("\n=== Step 1: get_public_key ===")
+        resp = run_one_request({
+            "id": "1",
+            "method": "get_public_key",
+            "params": [{"role": "main"}],
+        })
+        if resp is None or "result" not in resp:
+            print("ERROR: get_public_key failed")
+            print(f"Response: {resp}")
+            return 1
+        # The result is a plain hex string for secp256k1 backward compat.
+        pubkey_hex = resp["result"].strip('"')
+        print(f"Public key: {pubkey_hex}")
+
+        # Step 2: Encrypt the plaintext with OTP
+        print("\n=== Step 2: otp_encrypt ===")
+        pt_b64 = base64.b64encode(plaintext.encode()).decode()
+        resp = run_one_request({
+            "id": "2",
+            "method": "encrypt",
+            "params": [pt_b64, {"algorithm": "otp", "encoding": "ascii"}],
+        })
+        if resp is None or "result" not in resp:
+            print("ERROR: otp_encrypt failed")
+            print(f"Response: {resp}")
+            return 1
+        enc_result = json.loads(resp["result"])
+        ciphertext = enc_result["ciphertext"]
+        pad_chksum = enc_result["pad_chksum"]
+        pad_offset = enc_result["pad_offset_after"]
+        print(f"Pad checksum: {pad_chksum}")
+        print(f"Pad offset after encrypt: {pad_offset}")
+        print(f"Ciphertext (first 60 chars): {ciphertext[:60]}...")
+
+        # Step 3: Build the Nostr kind 30078 event
+        print("\n=== Step 3: Build kind 30078 event ===")
+        # Use a unique d-tag based on the pad checksum and offset.
+        d_tag = f"otp-{pad_chksum[:16]}-{pad_offset}"
+        event = {
+            "pubkey": pubkey_hex,
+            "created_at": int(time.time()),
+            "kind": 30078,
+            "tags": [
+                ["d", d_tag],
+                ["otp-pad", pad_chksum[:16]],
+                ["otp-version", "v0.0.2-otp"],
+                ["otp-encoding", "ascii"],
+            ],
+            "content": ciphertext,
+        }
+        # Compute the event ID.
+        event_id = compute_event_id(event)
+        event["id"] = event_id
+        print(f"Event ID: {event_id}")
+        print(f"d-tag: {d_tag}")
+
+        # Step 4: Sign the event with n_signer
+        print("\n=== Step 4: sign_event ===")
+        # sign_event expects the event JSON as the first param (without id/sig).
+        # The signer computes the id and signature internally.
+        event_for_signing = {
+            "pubkey": event["pubkey"],
+            "created_at": event["created_at"],
+            "kind": event["kind"],
+            "tags": event["tags"],
+            "content": event["content"],
+        }
+        resp = run_one_request({
+            "id": "3",
+            "method": "nostr_sign_event",
+            "params": [json.dumps(event_for_signing), {"role": "main"}],
+        })
+        if resp is None or "result" not in resp:
+            print("ERROR: sign_event failed")
+            print(f"Response: {resp}")
+            return 1
+        sig = resp["result"].strip('"')
+        event["sig"] = sig
+        print(f"Signature: {sig[:60]}...")
+
+        # Step 5: Print the signed event
+        print("\n=== Signed Nostr event (ready to publish) ===")
+        print(json.dumps(event, indent=2))
+        print(f"\nTo publish: send this event to a Nostr relay.")
+        print(f"To decrypt: call otp_decrypt with the content field.")
+        return 0
+    finally:
+        try:
+            os.unlink(MNEMONIC_TMP)
+        except OSError:
+            pass
+
+
+if __name__ == "__main__":
+    sys.exit(main())

examples/pq_kem_example.c

@@ -49,7 +49,8 @@ static int get_structured_pubkey(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return -1;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ml-kem-768");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
@@ -99,11 +100,12 @@ static int kem_encapsulate(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return -1;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ml-kem-768");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
-    if (nsigner_client_call(client, "kem_encapsulate", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "encapsulate", params, &result) != NOSTR_SUCCESS) {
         cJSON_Delete(params);
         return -1;
     }
@@ -147,11 +149,12 @@ static char *kem_decapsulate(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return NULL;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ml-kem-768");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
-    if (nsigner_client_call(client, "kem_decapsulate", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "decapsulate", params, &result) != NOSTR_SUCCESS) {
         cJSON_Delete(params);
         return NULL;
     }

examples/pq_sign_example.c

@@ -46,7 +46,8 @@ static int get_structured_pubkey(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return -1;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ml-dsa-65");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
@@ -89,11 +90,12 @@ static char *sign_data(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return NULL;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ml-dsa-65");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
-    if (nsigner_client_call(client, "sign_data", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "sign", params, &result) != NOSTR_SUCCESS) {
         cJSON_Delete(params);
         return NULL;
     }

examples/sign_event_client.c

@@ -73,7 +73,7 @@ int main(int argc, char **argv) {
     cJSON_AddItemToArray(params, opts);
     opts = NULL; /* owned by params now */
 
-    if (nsigner_client_call(client, "sign_event", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "nostr_sign_event", params, &result) != NOSTR_SUCCESS) {
         fprintf(stderr, "request failed: %s\n", nsigner_client_last_error(client));
         goto cleanup;
     }

examples/ssh_sign_example.c

@@ -47,7 +47,8 @@ static int get_structured_pubkey(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return -1;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ed25519");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
@@ -97,11 +98,12 @@ static char *ssh_sign(nsigner_client_t *client, const char *role,
         cJSON_Delete(params);
         return NULL;
     }
-    cJSON_AddStringToObject(opts, "role", role);
+    cJSON_AddStringToObject(opts, "algorithm", "ed25519");
+    cJSON_AddNumberToObject(opts, "index", 0);
     cJSON_AddItemToArray(params, opts);
     opts = NULL;
 
-    if (nsigner_client_call(client, "ssh_sign", params, &result) != NOSTR_SUCCESS) {
+    if (nsigner_client_call(client, "sign", params, &result) != NOSTR_SUCCESS) {
         cJSON_Delete(params);
         return NULL;
     }

firmware/README.md

@@ -53,6 +53,26 @@ WebUSB path:
 - Run `get_public_key`
 - Confirm pubkey matches CDC result
 
+## CYD (ESP32-2432S028) validation — Web Serial
+
+The CYD has no native USB; its CH340 bridge exposes a serial port. The browser
+transport is **Web Serial** (`navigator.serial`), Chromium-only. A full test
+page covering every algorithm and verb lives at
+[`examples/cyd_webserial_demo.html`](../examples/cyd_webserial_demo.html):
+
+- Open [`examples/cyd_webserial_demo.html`](../examples/cyd_webserial_demo.html) in Chrome/Edge
+- Click **Connect Web Serial**, select the CH340 port (`1a86:7523`)
+- Exercise each card: `get_public_key` (all 6 algorithms), `sign`/`verify`,
+  `encapsulate`/`decapsulate`, `derive_shared_secret`, `derive`,
+  `nostr_get_public_key`, `nostr_sign_event`, `nostr_mine_event`,
+  `nostr_nip04`/`nostr_nip44` encrypt+decrypt, and `encrypt`/`decrypt` (otp)
+- Each request shows the raw JSON-RPC request and response
+
+The CYD firmware (v0.0.2+) speaks the same algorithm-based API as the host
+([`README.md`](../README.md) §4). The OTP pad is derived from the mnemonic
+seed (no USB pad on this board); the offset advances monotonically and is
+reported in every `encrypt`/`decrypt` response.
+
 ## Linux WebUSB host setup (one-time)
 
 Chrome and Edge need permission to open the device on Linux. Install a udev rule for the firmware VID:PID and reload rules:
@@ -123,33 +143,34 @@ firmware uses a **crypto backend abstraction** ([`resources/pqclean/common/crypt
 with two implementations:
 
 - [`resources/pqclean/common/crypto_backend_openssl.c`](../resources/pqclean/common/crypto_backend_openssl.c) — host build (OpenSSL EVP)
-- [`resources/pqclean/common/crypto_backend_mbedtls.c`](../resources/pqclean/common/crypto_backend_mbedtls.c) — ESP32 firmware (mbedtls)
+- [`resources/pqclean/common/crypto_backend_mbedtls.c`](../resources/pqclean/common/crypto_backend_mbedtls.c) — ESP32 firmware (mbedtls + vendored Keccak)
 
 The mbedtls backend uses:
-- `mbedtls_sha256_ret()` for SHA-256 (ESP32-S3 hardware accelerated)
-- `mbedtls_sha512_ret()` for SHA-512 (ESP32-S3 hardware accelerated)
-- `mbedtls_md` API for SHA3-256, SHA3-512, SHAKE-128, SHAKE-256
+- `mbedtls_sha256()` for SHA-256 (ESP32 hardware accelerated where available)
+- `mbedtls_sha512()` for SHA-512 (ESP32 hardware accelerated where available)
+- A **self-contained Keccak-f[1600]** implementation (FIPS 202, public domain)
+  for SHA3-256, SHA3-512, SHAKE-128, and SHAKE-256. This is vendored directly
+  in `crypto_backend_mbedtls.c` because ESP-IDF v5.x mbedtls does not expose
+  SHAKE (and SHA3 is only available when `CONFIG_MBEDTLS_SHA3_C` is set) through
+  the `mbedtls_md` API. Carrying the Keccak core avoids any mbedtls config
+  dependency for the PQ algorithms.
 
-### Enabling SHA3/SHAKE in menuconfig
+### ed25519 / x25519 via PSA crypto
 
-mbedtls does not enable SHA3/SHAKE by default. You must enable them in
-menuconfig before building:
+ESP-IDF v5.x mbedtls removed the low-level `mbedtls_ed25519_*` functions. The
+firmware uses the **PSA Crypto API** for ed25519 sign/verify/key-derivation and
+x25519 key derivation + ECDH. Enable PSA in `sdkconfig.defaults`:
 
 ```
-Component config → mbedTLS → Hash functions → SHA-3
-Component config → mbedTLS → Hash functions → SHAKE
+CONFIG_MBEDTLS_PSA_CRYPTO_C=y
+CONFIG_MBEDTLS_ECP_DP_CURVE25519_ENABLED=y
 ```
 
-Or add to `sdkconfig.defaults`:
-```
-CONFIG_MBEDTLS_SHA3_C=y
-CONFIG_MBEDTLS_SHAKE_C=y
-```
+### No SHA3/SHAKE menuconfig requirement
 
-If mbedtls does not have SHAKE support, the firmware build will fail at link
-time with unresolved `mbedtls_md_info_from_type(MBEDTLS_MD_SHAKE128)`. In that
-case, either enable the config options above or patch mbedtls with a
-Keccak/SHAKE contribution.
+Because SHA3/SHAKE are provided by the vendored Keccak core (not mbedtls), you
+do **not** need to enable `CONFIG_MBEDTLS_SHA3_C` or any SHAKE config. The PQ
+algorithms build and run with the default mbedtls configuration.
 
 ### PQClean component
 

firmware/ble_wearable_signer/README.md

@@ -0,0 +1,81 @@
+# n_signer BLE Wearable Signer
+
+**Status:** Concept — brainstorming. No plan yet.
+
+A small, battery-powered wearable hardware signer that communicates with a host
+over **Bluetooth Low Energy (BLE)**. The host sends JSON-RPC requests over a
+BLE GATT characteristic; the signer shows an approval prompt on a tiny display;
+the user taps a button to approve; the signed response goes back over BLE.
+
+## Concept
+
+```mermaid
+flowchart LR
+    Host[Host: phone/laptop<br/>n_signer client] -->|BLE GATT| Signer[Wearable signer<br/>nRF52840 + OLED]
+    Signer -->|approve/deny button| User[User]
+    Signer -->|BLE GATT response| Host
+```
+
+The signer speaks the same algorithm-based API as the host and the CYD/Teensy
+firmware ([`README.md`](../../README.md) §4). The auth envelope (kind 27235)
+protects the BLE wire — even if BLE is sniffed, an attacker can't forge
+requests without the caller's secp256k1 private key.
+
+## Why BLE
+
+- **Wearable form factor** — always with you (wristband, pendant, card)
+- **No physical connection** — no USB cable, no host-side driver, no dongle
+- **Universal host support** — phones, laptops, tablets all have BT
+- **Low power** — nRF52840 draws ~5 mA active, ~1 µA sleep
+
+## Hardware (preliminary)
+
+| Component | Candidate | Notes |
+|---|---|---|
+| MCU | **nRF52840** (Nordic) | Cortex-M4 @ 64 MHz, 1 MB flash, 256 KB RAM, BT 5.0, hardware AES/ECC, USB device, NFC-A. ~$5-8. |
+| Display | 0.96" or 1.3" SSD1306 OLED (I2C) or 1.02" e-paper | Small is fine — only shows "approve kind 1 from <caller>?" |
+| Input | 2-3 tactile buttons (approve/deny/back) | No touch at this size |
+| Power | 200 mAh coin cell or small LiPo | Weeks of battery life |
+| Mnemonic entry | Buttons (scroll words), NFC from phone, or generate-on-device | The hard UX problem |
+
+## Security considerations
+
+- **BT stack attack surface:** BLE has a large stack (pairing, GATT, L2CAP, SMP).
+  A stack bug could allow code execution. Mitigations: use Nordic's audited
+  SoftDevice, disable unnecessary services, require LE Secure Connections pairing.
+- **Radio range (~10 m):** an attacker in the same room could potentially
+  interact with the signer. The auth envelope + approval prompt protect against
+  this, but the radio is omnidirectional.
+- **Pairing UX:** BT pairing can be frustrating. LE Secure Connections (Numeric
+  Comparison) is the most secure and user-friendly pairing method.
+
+## Open questions
+
+- **Mnemonic entry on a tiny screen:** scroll through 2048 BIP-39 words with
+  up/down buttons (like Coldcard)? Load via NFC from a phone? Generate on-device
+  and display for the user to write down?
+- **PQ crypto on nRF52840:** 256 KB RAM is enough for ML-DSA-65 (~6 KB heap)
+  but SLH-DSA-128s is heavy. May need to limit the PQ algorithm set or stream
+  the keygen.
+- **Display choice:** OLED (fast refresh, high power) vs e-paper (slow refresh,
+  zero power when static, persistent display).
+- **Form factor:** wristband? pendant? card? What's the target use case —
+  daily signing, emergency key access, or a backup signer?
+
+## Comparison to the IR air-gap signer
+
+| | BLE wearable | IR air-gap |
+|---|---|---|
+| Air-gap | Medium (radio, ~10 m, omnidirectional) | High (light, line-of-sight, ~1 m) |
+| Attack surface | Large (BT stack) | Small (no BT, dumb dongle) |
+| Host compatibility | Universal (phones, laptops) | Requires USB dongle |
+| Form factor | Wearable | Handheld (point at dongle) |
+| Throughput | ~250 KB/s (BLE 5) | ~11 KB/s (raw IR) or ~400 KB/s (IrDA) |
+| Novelty | Conventional | Novel (no hardware wallet uses IR) |
+
+## Next steps
+
+- Decide on the MCU (nRF52840 vs RP2040+BT-module)
+- Decide on mnemonic entry method
+- Decide on display (OLED vs e-paper)
+- Write a port plan (similar to [`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md))

firmware/cyd_esp32_2432s028/README.md

@@ -0,0 +1,175 @@
+# n_signer CYD Firmware (ESP32-2432S028)
+
+The **Cheap Yellow Display** (ESP32-2432S028) is a $15 ESP32-WROOM-32 board with
+a 2.8" 320×240 ILI9341 resistive-touch display, CH340 USB-UART bridge, and a
+Micro SD card slot. This firmware turns it into a hardware n_signer that speaks
+the same algorithm-based API as the host ([`README.md`](../../README.md) §4).
+
+**Firmware version:** 0.0.2 (algorithm-based API)
+
+## Hardware summary
+
+| Concern | Value |
+|---|---|
+| MCU | ESP32-WROOM-32 (classic, dual-core Xtensa, 512 KB SRAM, no PSRAM) |
+| USB-UART | CH340 (`1a86:7523`) → `/dev/ttyUSB0` |
+| Flash | 4 MB |
+| Display | 2.8" 320×240 ILI9341 (HSPI: DC=IO2, CS=IO15, SCK=IO14, MOSI=IO13, MISO=IO12, BL=IO21) |
+| Touch | XPT2046 resistive (bit-banged SPI: CLK=IO25, MOSI=IO32, CS=IO33, MISO=IO39, IRQ=IO36) |
+| SD card | Micro SD, VSPI (CS=IO5, SCK=IO18, MISO=IO19, MOSI=IO23) |
+| RGB LED | R=IO4, G=IO16, B=IO17 (active LOW) |
+| LDR | IO34 |
+| Speaker | IO26 (DAC) |
+| BOOT button | IO0 |
+| GUI | LVGL 8.3 |
+
+For the full pin map, connectors (P1/P3/CN1), and add-ons, see the upstream
+hardware docs copied to [`docs/`](docs/) — especially
+[`docs/PINS.md`](docs/PINS.md) and [`docs/SETUP.md`](docs/SETUP.md).
+
+## SD card — size limits and OTP pad storage
+
+The CYD's Micro SD slot is wired to VSPI (IO5/18/19/23). ESP-IDF drives it via
+the SDSPI host + FATFS filesystem. The proven bring-up example is
+`07_sd_card` in the `esp32_playground/cyb-esp32-2432s028/` workspace.
+
+**Size limits:**
+
+- **SDSC (≤ 2 GB):** supported.
+- **SDHC (2 GB – 32 GB):** supported — this is the recommended range. The
+  Makerfabs CYD ships with a 16 GB card, which works.
+- **SDXC (> 32 GB):** **not supported** out of the box. SDXC cards ship
+  formatted as exFAT, and ESP-IDF's FATFS does not include exFAT. An SDXC card
+  reformatted to FAT32 will work up to 32 GB; beyond that, FAT32's 32 GB limit
+  applies. For OTP pad storage, 32 GB is vastly more than enough (see below).
+
+**Recommendation:** use any **SDHC card from 4–32 GB** formatted **FAT32**.
+
+### Using the SD card for the OTP pad
+
+The current v0.0.2 firmware derives the OTP pad from the mnemonic seed via
+HKDF-SHA256 into a 1024-byte in-RAM pad (no SD card required). This keeps the
+wire contract identical to the host's `encrypt`/`decrypt` (algorithm:"otp")
+verbs but limits the pad to 1024 bytes per session.
+
+To hold a **large OTP pad** (the original n_signer host design binds a pad file
+from `--otp-pad-dir`), the SD card is the right storage. The plan:
+
+1. Format the SD card as FAT32.
+2. Place a pad file (e.g. `nsigner.pad`) on it — any size up to the card's free
+   space. A 1 GB pad gives ~1 billion one-time-pad bytes before exhaustion.
+3. The firmware mounts the SD card at boot via `esp_vfs_fat_sdmmc_mount()` on
+   the SDSPI host, opens the pad file, and reads pad bytes on demand into a
+   small ring buffer, advancing a persistent offset (stored in a small
+   `nsigner.offset` file on the SD so the offset survives power cycles).
+4. The `encrypt`/`decrypt` verbs XOR against the SD-backed pad instead of the
+   HKDF-derived in-RAM pad.
+
+This is a planned enhancement (see [`plans/cyd_algorithm_api_upgrade.md`](../../plans/cyd_algorithm_api_upgrade.md)
+§13 — the current implementation uses the mnemonic-derived pad as the embedded
+fallback). The SD card slot is confirmed working and the pin map is in
+[`docs/PINS.md`](docs/PINS.md).
+
+**Note on simultaneous display + touch + SD:** The CYD's display (HSPI), touch
+(bit-banged), and SD (VSPI) use three different SPI buses. All three can run at
+the same time — the touch is bit-banged precisely so it doesn't contend with
+the other two hardware SPI buses (see [`docs/TROUBLESHOOTING.md`](docs/TROUBLESHOOTING.md)).
+
+## Building and flashing
+
+Requires ESP-IDF v5.x (tested with v5.4.2). The classic ESP32 target uses the
+`xtensa-esp-elf` unified toolchain.
+
+```bash
+source /home/user/esp/esp-idf/export.sh
+cd firmware/cyd_esp32_2432s028
+idf.py build
+idf.py -p /dev/ttyUSB0 flash
+```
+
+If flashing fails with `Wrong boot mode detected (0x13)`, see the serial-reset
+hardware note below.
+
+## Validation — Web Serial
+
+The CYD has no native USB; the CH340 bridge exposes a serial port. The browser
+transport is **Web Serial** (`navigator.serial`), Chromium-only. A full test
+page covering every algorithm and verb lives at
+[`examples/cyd_webserial_demo.html`](../../examples/cyd_webserial_demo.html):
+
+1. Open [`examples/cyd_webserial_demo.html`](../../examples/cyd_webserial_demo.html) in Chrome/Edge.
+2. Click **Connect Web Serial**, select the CH340 port (`1a86:7523`).
+3. On the CYD touchscreen, enter or generate a mnemonic to reach the "ready" state.
+4. Exercise each card: `get_public_key` (all 6 algorithms), `sign`/`verify`,
+   `encapsulate`/`decapsulate`, `derive_shared_secret`, `derive`,
+   `nostr_get_public_key`, `nostr_sign_event`, `nostr_mine_event`,
+   `nostr_nip04`/`nostr_nip44` encrypt+decrypt, and `encrypt`/`decrypt` (otp).
+
+## API
+
+The CYD firmware speaks the same algorithm-based API as the host n_signer
+([`README.md`](../../README.md) §4). Supported verbs:
+
+| Verb | Algorithms |
+|---|---|
+| `get_public_key` | secp256k1, ed25519, x25519, ml-dsa-65, slh-dsa-128s, ml-kem-768 |
+| `sign` / `verify` | secp256k1 (schnorr/ecdsa), ed25519, ml-dsa-65, slh-dsa-128s |
+| `encapsulate` / `decapsulate` | ml-kem-768 |
+| `derive_shared_secret` | x25519 |
+| `derive` | secp256k1 (HMAC-SHA256) |
+| `encrypt` / `decrypt` | otp |
+| `nostr_get_public_key` | secp256k1 (NIP-06) |
+| `nostr_sign_event` | secp256k1 (NIP-06) |
+| `nostr_mine_event` | secp256k1 (NIP-06, single-threaded PoW) |
+| `nostr_nip04_encrypt` / `decrypt` | secp256k1 (NIP-06) |
+| `nostr_nip44_encrypt` / `decrypt` | secp256k1 (NIP-06) |
+
+All requests require an auth envelope (kind 27235). The `key_id` in every
+structured result is the first 16 hex characters of the public key, matching
+the host. Invalid `(verb, algorithm)` pairs return error `1010`.
+
+### Embedded-specific notes
+
+- **OTP pad:** derived from the mnemonic seed (HKDF-SHA256, 1024 bytes) in
+  v0.0.2. The offset advances monotonically and is reported in every
+  `encrypt`/`decrypt` response. SD-card-backed pad is a planned enhancement
+  (see above).
+- **`nostr_mine_event`:** single-threaded, hard 30 s default timeout, shows a
+  "mining…" screen. Keep difficulty low (≤ 8) on ESP32.
+- **SLH-DSA-128s:** keygen and signing take 5–30 s. The UI shows a "deriving
+  key…" / "signing…" indicator. ML-DSA-65 is much faster (~100 ms) and is the
+  recommended PQ signature algorithm for interactive use.
+
+## Crypto backend
+
+- **SHA-256 / SHA-512:** mbedtls (ESP32 hardware accelerated).
+- **SHA3 / SHAKE-128 / SHAKE-256:** vendored Keccak-f[1600] (FIPS 202) in
+  [`resources/pqclean/common/crypto_backend_mbedtls.c`](../../resources/pqclean/common/crypto_backend_mbedtls.c).
+  No `CONFIG_MBEDTLS_SHA3_C` or SHAKE menuconfig dependency.
+- **ed25519 / x25519:** PSA Crypto API (`psa_import_key`, `psa_sign_message`,
+  `psa_raw_key_agreement`, etc.) — ESP-IDF v5.x mbedtls removed the
+  `mbedtls_ed25519_*` functions. Requires `CONFIG_MBEDTLS_PSA_CRYPTO_C=y`
+  (set in [`sdkconfig.defaults`](sdkconfig.defaults)).
+- **secp256k1:** the vendored secp256k1 component (schnorr + ECDSA).
+- **PQ (ML-DSA-65, SLH-DSA-128s, ML-KEM-768):** PQClean via the
+  [`components/pqclean/`](components/pqclean/) component.
+
+## Serial-reset hardware note (CH340 auto-reset)
+
+Opening `/dev/ttyUSB0` can reset the ESP32 because the CH340's DTR/RTS lines
+are wired into the ESP32 auto-reset circuit. Symptoms: the device returns to
+the startup menu when a host app opens the serial port.
+
+**Mitigation:** add a **10 µF capacitor between EN and GND** on the CYD board
+(negative leg to GND). Typical working range is 4.7–22 µF. This also fixes the
+`Wrong boot mode detected (0x13)` flashing error. See
+[`docs/TROUBLESHOOTING.md`](docs/TROUBLESHOOTING.md) and the
+[`firmware/README.md`](../README.md) CYD section for details.
+
+## Reference documentation
+
+- [`docs/`](docs/) — upstream CYD hardware docs (PINS, SETUP, TROUBLESHOOTING, ADDONS, etc.)
+- [`plans/cyd_signer_port.md`](../../plans/cyd_signer_port.md) — original port plan (hardware comparison, architecture, UI flow)
+- [`plans/cyd_algorithm_api_upgrade.md`](../../plans/cyd_algorithm_api_upgrade.md) — v0.0.2 API upgrade plan
+- [`firmware/README.md`](../README.md) — shared firmware README (PQ crypto, mbedtls backend, feather target)
+- [`README.md`](../../README.md) §4 — the authoritative n_signer API reference

firmware/cyd_esp32_2432s028/docs/ADDONS.md

@@ -0,0 +1,86 @@
+# Add-Ons
+
+Here is a list of additional hardware add-ons that can add functionality to your CYD
+
+## SD Card Sniffer
+
+If you want to use the pins of the SD card for a different purpose, the easiest way to do that is with an "SD card sniffer", which basically plugs into the SD card slot and breaks out the pins. It's particularly useful for SPI devices.
+
+## Pin-out of the Sniffer board
+
+| Sniffer Board Label | ESP32 Pin | SPI Use   |
+| ------------------- | --------- | --------- |
+| DAT2                | -         | -         |
+| CD                  | IO5       | CS        |
+| CMD                 | IO23      | DI / MOSI |
+| GND                 | GND       | -         |
+| VCC                 | 3.3V      | -         |
+| CLK                 | IO18      | SCLK      |
+| DAT0                | IO19      | DO / MISO |
+| DAT1                | -         | -         |
+
+### Links
+
+- [Micro SD Card Sniffer - Aliexpress\*](https://s.click.aliexpress.com/e/_Ddwcy9h)
+
+## Nintendo Wii Nunchuck
+
+A Nunchuck controller from a Nintendo Wii is a great input device for CYD projects as they are inexpensive and, since they use i2c for communication, they only require 2 GPIO pins to connect them up.
+
+For these two pins you get:
+
+- An analog stick
+- 2 Buttons
+- An accelerometer
+
+### Hardware Required
+
+#### Nunchuck controllers
+
+Official Nintendo ones are generally better (maybe try second-hand options), but third-party ones also work fine.
+
+- [Amazon.co.uk Search\*](https://amzn.to/3nQrXcE)
+- [Amazon.com Search\*](https://amzn.to/3nRJTUd)
+- [Aliexpress (Third Party)\*](https://s.click.aliexpress.com/e/_AaQbXh)
+
+#### Nunchuck Adaptors
+
+There are many different options available for these, even the cheap ones from Aliexpress work perfectly.
+
+- [Aliexpress](https://s.click.aliexpress.com/e/_AEEtc3)
+- [My Open source one from Oshpark](https://oshpark.com/shared_projects/RcIxSx2D)
+- [Adafaruit](https://www.adafruit.com/product/4836)
+
+### Wiring
+
+The easiest way to wire this up is to use the wire that came with the CYD and the **CN1** JST connector (the one closest to the Micro SD card slot)
+
+Connect the wire to your breakout board as follows:
+
+| CYD CN1 | Adapter     | Note               |
+| ------- | ----------- | ------------------ |
+| GND     | - (AKA GND) | Black wire for me  |
+| 3.3V    | + (AKA 3V)  | Red wire for me    |
+| IO22    | d (AKA SDA) | Blue wire for me   |
+| IO27    | c (AKA SCL) | Yellow wire for me |
+
+Note: I have found pull-ups resistors are not required on SDA and SCL
+
+### Example
+
+Check out the [NunchuckTest](/Examples/InputTests/NunchuckTest) example for code how to use it.
+
+## Speakers
+
+A speaker can be attached to the display with a 1.25mm JST connector to the connector labeled "SPEAK" (or soldered)
+
+Check out the [HelloRadio](/Examples/Basics/7-HelloRadio) example for the code on how to use it.
+
+Most small 8 Ohm speakers should work. Maybe worth adding a 1.25mm JST connector to it to make it easy to add remove.
+
+### Links
+
+- [Speaker with 1.25mm JST connector (2pcs) - Aliexpress\*](https://s.click.aliexpress.com/e/_DBOJoh7) - Tested, works right out of the package.
+- [2pin 1.25mm JST connectors - Aliexpress\*](https://s.click.aliexpress.com/e/_DlbPkWH) - Not purchased by me, but should work
+
+\* = Affiliate Link - It doesn't cost you any extra but I receive a small portion of the sale.

firmware/cyd_esp32_2432s028/docs/MEDIA.md

@@ -0,0 +1,14 @@
+# Media and Mentions
+
+This page can document any times the CYD project was mentioned somewhere!
+
+## Videos
+
+- [Brian Lough (hey, thats me!) - Cheap and Easy to Use ESP32 Screen!](https://www.youtube.com/watch?v=0AVyvwv0agk)
+- [Talking Sasquach - Don't be Fooled!! This Cheap Yellow Display Can Do a LOT!!](https://youtu.be/PsqMCoCTgTg?feature=shared)
+- [Teaching Tech - Cheap and easy Klipper touch interface with CYD Klipper](https://youtu.be/R3o0MGYW1ZU?feature=shared)
+
+## Articles
+
+- [Hackaday.com - “Cheap Yellow Display” Builds Community Through Hardware](https://hackaday.com/2023/10/28/cheap-yellow-display-builds-community-through-hardware/)
+- [Hackster.io - Brian Lough Looks to Build a Community Around the Espressif ESP32-Powered "Cheap Yellow Display"](https://www.hackster.io/news/brian-lough-looks-to-build-a-community-around-the-espressif-esp32-powered-cheap-yellow-display-66d23972910d)

firmware/cyd_esp32_2432s028/docs/PINS.md

@@ -0,0 +1,140 @@
+# Pins
+
+This page talks about the pins on the CYD.
+
+## Connector types
+
+The connectors are often called "1.25mm JST" but the correct name is "Molex PicoBlade".
+Chinese clones are sometimes called "mx1.25".
+
+|Connector|Type    |Note                  |
+|---      |---     |----                  |
+|[**P1**](#p1)  |4P 1.25mm Molex PicoBlade|Serial     |
+|[**P3**](#p3)  |4P 1.25mm Molex PicoBlade|GPIO       |
+|[**P4**](#p4)  |2P 1.25mm Molex PicoBlade|Speaker    |
+|[**CN1**](#cn1)|4P 1.25mm Molex PicoBlade|GPIO (I2C) |
+
+## What pins are available on the CYD?
+
+There are 3 easily accessible GPIO pins
+
+|Pin|Location|Note|
+|---|---|----|
+|IO35|**P3** Molex PicoBlade connector|Input only pin, no internal pull-ups available|
+|IO22|**P3** and **CN1** Molex PicoBlade connector||
+|IO27|**CN1** Molex PicoBlade connector||
+
+If you need more than that, you need to start taking them from something else. An SD Card sniffer like mentioned in the [Add-ons](/ADDONS.md) is probably the next easiest.
+
+After that you're probably de-soldering something!
+
+## Broken Out Pins
+
+There are three 4P 1.25mm Molex PicoBlade connectors on the board.
+
+### P3
+|Pin|Use|Note|
+|---|---|----|
+|GND|||
+|IO35||Input only pin, no internal pull-ups available|
+|IO22||Also on the **CN1** connector|
+|IO21||Used for the TFT Backlight, so not really usable|
+
+### CN1
+This is a great candidate for I2C devices
+
+|Pin|Use|Note|
+|---|---|----|
+|GND|||
+|IO22||Also on **P3** connector|
+|IO27|||
+|3.3V|||
+
+### P1
+|Pin|Use|Note|
+|---|---|----|
+|VIN|||
+|IO1(?)|TX|Maybe possible to use as a GPIO?|
+|IO3(?)|RX|Maybe possible to use as a GPIO?|
+|GND|||
+
+
+## Buttons
+
+The CYD has two buttons, reset and boot.
+
+|Pin|Use|Note|
+|---|---|----|
+|IO0|BOOT|Can be used as an input in sketches|
+
+## Speaker
+
+The speaker connector is a 2P 1.25mm Molex PicoBlade connector that is connected to the amplifier, so not usable as GPIO at the speaker connector
+
+|Pin|Use|Note|
+|---|---|----|
+|IO26|Connected to amp|`i2s_set_dac_mode(I2S_DAC_CHANNEL_LEFT_EN);`|
+
+## RGB LED
+
+If your project requires additional pins to what is available elsewhere, this might be a good candidate to sacrifice.
+
+Note: LEDs are "active low", meaning HIGH == off, LOW == on
+
+|Pin|Use|Note|
+|---|---|----|
+|IO4|Red LED||
+|IO16|Green LED||
+|IO17|Blue LED||
+
+## SD Card
+Uses the VSPI
+Pin names are predefined in SPI.h
+
+|Pin|Use|Note|
+|---|---|----|
+|IO5|SS||
+|IO18|SCK||
+|IO19|MISO||
+|IO23|MOSI||
+
+## Touch Screen
+
+|Pin|Use|Note|
+|---|---|----|
+|IO25|XPT2046_CLK||
+|IO32|XPT2046_MOSI||
+|IO33|XPT2046_CS||
+|IO36|XPT2046_IRQ||
+|IO39|XPT2046_MISO||
+
+## LDR (Light Sensor)
+
+|Pin|Use|Note|
+|---|---|----|
+|IO34|||
+
+## Display
+Uses the HSPI
+
+|Pin|Use|Note|
+|---|---|----|
+|IO2|TFT_RS|AKA: TFT_DC|
+|IO12|TFT_SDO|AKA: TFT_MISO|
+|IO13|TFT_SDI|AKA: TFT_MOSI|
+|IO14|TFT_SCK||
+|IO15|TFT_CS||
+|IO21|TFT_BL|Also on P3 connector, for some reason|
+
+## Test points
+|Pad|Use|Note|
+|---|---|----|
+|S1|GND|near USB-SERIAL|
+|S2|3.3v|for ESP32|
+|S3|5v|near USB-SERIAL|
+|S4|GND|for ESP32|
+|S5|3.3v|for TFT|
+|JP0 (pad nearest USB socket)|5v|TFT LDO|
+|JP0|3.3v|TFT LDO|
+|JP3 (pad nearest USB socket)|5v|ESP32 LDO|
+|JP3|3.3v|ESP32 LDO|

firmware/cyd_esp32_2432s028/docs/PROJECTS.md

@@ -0,0 +1,60 @@
+# Projects
+
+Because the CYD is a common platform, it makes it really useful for sharing projects. This page will be a list of projects that are available on the CYD.
+
+## Disclaimer!
+
+Projects appearing on here is not necessarily a seal of approval from me, I will not be test each project that gets added, so please install these projects at your own risk!
+
+## Projects
+
+| Name                   | Description                                                                                 | Author                                                 | Additional Hardware?                                                   | Project Page                                                       | WebFlash                                                                 |
+| ---------------------- | ------------------------------------------------------------------------------------------- | ------------------------------------------------------ | ---------------------------------------------------------------------- | ------------------------------------------------------------------ | ------------------------------------------------------------------------ |
+| Spotify DIY Thing      | A device for displaying your currently playing Spotify track                                | [Brian Lough](https://github.com/witnessmenow)         |                                                                        | [Github](https://github.com/witnessmenow/Spotify-Diy-Thing)        | [WebFlash](https://witnessmenow.github.io/Spotify-Diy-Thing/)   |
+| F1 Notifier            | Displays and notifies you of the F1 session times(in your local timezone)                   | [Brian Lough](https://github.com/witnessmenow)         |                                                                        | [Github](https://github.com/witnessmenow/F1-Arduino-Notifications) | [WebFlash](https://witnessmenow.github.io/F1-Arduino-Notifications/)     |
+| Tetris with Nunchuck   | A version of Tetris using a Nintendo wii Nunchuck                                           | [Brian Lough](https://github.com/witnessmenow)         | A nunchuck and an adaptor for connecting it                            | [Code](/Examples/Projects/TetrisWithNunchuck)                      |                                                                          |
+| Galagino               | An emulator for some classic arcade games (Galaga, Donkey Kong, Pacman, Digdug and Frogger) | [Till Harbaum](https://github.com/harbaum)             | A nunchuck and an adaptor for connecting it. Speaker if you want sound | [Github](https://github.com/harbaum/galagino)                      |                                                                          |
+| ESP32-fluid-simulation | A small fluid simulation with touch input                                                   | [Kenny Peng](https://github.com/colonelwatch)          |                                                                        | [Github](https://github.com/colonelwatch/ESP32-fluid-simulation)   |                                                                          |
+| ESP32-TV               | Play Video Files on the ESP32                                                               | [atomic14](https://github.com/atomic14)                | Speaker if you want sound and possibly an IR receiver                  | [Github](https://github.com/atomic14/esp32-tv)                     |                                                                          |
+| xtouch                 | "The xtouch screen is a revolutionary addition to your BambuLab Printer"                    | [xperiments-in](https://github.com/xperiments-in) (\#) |                                                                        | [Github](https://github.com/xperiments-in/xtouch)                  | [Webflash](https://github.com/xperiments-in/xtouch#online-web-installer) |
+| CYD-Klipper            | An implementation of a wireless Klipper status display on an ESP32 + screen                 | [Sims](https://github.com/suchmememanyskill)           |                                                                        | [Github](https://github.com/suchmememanyskill/CYD-Klipper)         | [Webflash](https://suchmememanyskill.github.io/CYD-Klipper/)             |
+| DRO (for lathe / mill) | A DRO (digital readout) for your lathe or mill                                              | [Alanesq](https://github.com/alanesq)                  | It uses cheap digital caliper, requires a very basic interface         | [Github](https://github.com/alanesq/DRO)                           |                                                                          |
+| ESP32Marauder-CYD      | A suite of WiFi/Bluetooth offensive and defensive tools for the ESP32                       | [Fr4nkFletcher](https://github.com/Fr4nkFletcher)      | GPS if you want BT/Wifi wardriving options                             | [Github](https://github.com/Fr4nkFletcher/ESP32-Marauder-Cheap-Yellow-Display)         | [Webflash](https://fr4nkfletcher.github.io/Adafruit_WebSerial_ESPTool/)             |
+| NerdMiner_v2           | A project that lets you try to solve a bitcoin block with a small piece of hardware.        | [Fr4nkFletcher](https://github.com/Fr4nkFletcher)      |                                                                        | [Github](https://github.com/Fr4nkFletcher/NerdMiner_v2-Cheap-Yellow-Display)         | [Webflash](https://fr4nkfletcher.github.io/NerdMiner_v2-Cheap-Yellow-Display/flash.html)             |
+| Tasmota                | Tasmota (with UI) on the CYD                                                                | ? (\#)                                                 |                                                                        | [Templates](https://templates.blakadder.com/sunton_ESP32-2432S028.html) | [Webflash](https://tasmota.github.io/install/)                      |
+| BAM | A game engine featuring smooth scrolling tile map, sprites in layers with pixel precision on-screen collision detection, intuitive definition of game objects and logic, decent performance, ~30 frames per second on the device | [calint](https://github.com/calint) | | [Github](https://github.com/calint/bam) | |
+|London Underground Arrivals| A highly configurable application that replicates the train arrivals boards found in [TFL](https://tfl.gov.uk/) stations. All variable data is encoded in a json file that may be updated at any time without the need to recompile the application e.g. the station to be displayed or the time to refresh data from TFL. The source code already supports 2 variants of CYD and, I hope, contains clear instructions how to handle any other variant.| [David Henry](https://github.com/mgaman) | | [Github](https://github.com/mgaman/TFL-tube-arrivals-board-ESP32-TFT-Arduino) |
+|GitHub-Stats| This Arduino project fetches and displays GitHub repository statistics such as star count, open issues, forks and notifactions on a CYD or via serial communication. Ideal for developers to monitor project metrics in real time.| [ATOMNFT](https://github.com/ATOMNFT) | | [Github](https://github.com/ATOMNFT/ESP32-CYD-Projects/tree/main/GitHub-Stats) | |
+| Midbar-Firebase-Edition | An advanced password vault that stores the encrypted data in the cloud while keeping the cryptographic keys on the edge! | [Northstrix](https://github.com/Northstrix) | PS/2 keyboard and an optional STM32F103C8T6 (if you want it to emulate the USB keyboard)  | [SourceForge](https://sourceforge.net/projects/midbar-firebase-edition/) [Github](https://github.com/Northstrix/Midbar-Firebase-Edition)
+| Electronic-Shelf-Label-Management-System | A simple device for displaying relevant product information. It gets the encrypted images via UDP. | [Northstrix](https://github.com/Northstrix)|                                                           | [SourceForge](https://sourceforge.net/projects/esl-management-system/) [Github](https://github.com/Northstrix/Electronic-Shelf-Label-Management-System)
+| ESP32-Tetris-With-Nintendo-64-Controller | Tetris for ESP32 with Nintendo 64 controller support                      | [Northstrix](https://github.com/Northstrix) | Nintendo 64 Controller and Arduino Nano                                           | [SourceForge](https://sourceforge.net/projects/esp32-tetris/) [Github](https://github.com/Northstrix/ESP32-Tetris-With-Nintendo-64-Controller)
+| Midbar ESP32 CYD       | A version of Midbar data vault tweaked specifically for the ESP32 Cheap Yellow Display.     | [Northstrix](https://github.com/Northstrix) | PS/2 Keyboard                                                                     | [SourceForge](https://sourceforge.net/projects/midbar-esp32-cyd/) [Github](https://github.com/Northstrix/Midbar-ESP32-CYD)
+| ESP32-Cheap-Yellow-Display-Electronic-Shelf-Label-with-Google-Firebase  | An ESP32 CYD-based Electronic Shelf Label that makes use of the Google Firebase and AES-256.  | [Northstrix](https://github.com/Northstrix) |                                | [SourceForge](https://sourceforge.net/projects/esp32-cyd-esl-with-firebase/)  [Github](https://github.com/Northstrix/ESP32-Cheap-Yellow-Display-Electronic-Shelf-Label-with-Google-Firebase)                                                                                                                                                                                                                         | [WebFlash](https://northstrix.github.io/ESP32-Cheap-Yellow-Display-Electronic-Shelf-Label-with-Google-Firebase/flash.html) </br>!!! Format Flash area designated for SPIFFS with [ESP32 Filesystem Uploader](https://github.com/me-no-dev/arduino-esp32fs-plugin/releases/) after using the WebFlash
+| Addressable RGB LED Strip Controller (The Lantern Project)              | DIY Addressable RGB LED Strip Controller that utilizes the ESP32, ESP8266, and the WS2812 LED Strip.  | [Northstrix](https://github.com/Northstrix) | Nintendo Wii Nunchuk, WiiChuck Nunchuck Adapter (PCB Board), ESP8266, 580 Ohm resistor, WS2812 LED Strip | [SourceForge](https://sourceforge.net/projects/the-lantern-project/)          [Github](https://github.com/Northstrix/Lantern)
+| Midbar ESP32 CYD Firebase Edition                                       | A version of Midbar data vault adapted for the ESP32 CYD and WebFlash. It keeps the cryptographic keys in the ESP32 RAM and stores the ciphertexts (encrypted data) in the Google Firebase.  | [Northstrix](https://github.com/Northstrix) (Adapted for CYD2USB by [Rovel](https://github.com/Rovel))| PS2 Keyboard, PS2 Port *optional | [SourceForge](https://sourceforge.net/projects/midbar-esp32-cyd-firebase/)          [Github (CYD)](https://github.com/Northstrix/Midbar-ESP32-CYD-Firebase-Edition) [Github (CYD2USB)](https://github.com/Northstrix/Midbar-ESP32-CYD2USB-Firebase-Edition)  | [WebFlash (CYD)](https://northstrix.github.io/Midbar-ESP32-CYD-Firebase-Edition/flash) [WebFlash (CYD2USB)](https://northstrix.github.io/Midbar-ESP32-CYD2USB-Firebase-Edition/flash)
+| cydOS  (WIP) | cydOS is a GUI app that is able to manage various aspects of the CYD, like SD browsing and file mangement, on board flashing of .bin files for rapid firmware switching, on board device settings(WIP)  | [orlandobianco](https://github.com/orlandobianco) | | [Github]((https://github.com/orlandobianco/cydOS))  | |
+| ESP32 MFA Authenticator | Turn the CYD into a MFA Authenticator | [AllanOricil](https://github.com/AllanOricil) | | [Github](https://github.com/AllanOricil/esp32-mfa-authenticator)  | [Webflash](https://allanoricil.github.io/esp32-mfa-authenticator/)
+| cydWeatherStation | cyd Weather station | [gustheseventh](https://github.com/gustheseventh) (#) | | [Github](https://github.com/gustheseventh/cyd-Weather-Station)  | |
+| PhilRadio | CYD Wifi Radio project. Re-using an old radio as hardware. Exposing a webserver on local network to configure the radio stations. Persistent storage. | [mogrikid](https://github.com/mogrikid) | Required: A speaker. Recommended:  Speaker, potentiometer, 10kohm resistor, female usb port, switch | [Github](https://github.com/mogrikid/PhilRadio)
+| cydWeeWX | Simple CYD Weather Display for the open source [WeeWX](https://www.weewx.com/) weather station server. | [hcomet](https://hcomet.github.io/) | | [Github](https://github.com/hcomet/cydWeeWX)| [Webflash](https://hcomet.github.io/cydWeeWX/cydWeeWXFlash.html) |
+| CYD Stream Deck        | A customizable touch-based Bluetooth HID controller using CYD.         | [gahingwoo](https://github.com/gahingwoo)             |     | [GitHub](https://github.com/gahingwoo/cyd-stream-deck)            | [Webflash](https://gahingwoo.github.io/cyd-stream-deck/webflash/index.html)  |
+| CYD DHT22 Weather Clock | A weather and time display using CYD.       | [gahingwoo](https://github.com/gahingwoo)             | DHT22 sensor | [GitHub](https://github.com/gahingwoo/cyd-dht22-weather-clock) | |
+| ESP CYD MCP | Model Context Protocol (MCP) server implementation for the ESP32 CYD | [OfryL](https://github.com/OfryL) | | [Github](https://github.com/OfryL/esp-cyd-mcp) | |
+| Aura |  Smart weather forecast device (OpenMeteo) | [Surrey-Homeware](https://github.com/Surrey-Homeware/) (\#) | [3D printed case](https://makerworld.com/en/models/1382304-aura-smart-weather-forecast-display#profileId-1430951) | [Github](https://github.com/Surrey-Homeware/Aura) | [Webflash](https://surrey-homeware.github.io/aura-installer/) |
+| SmartEnergyMeter | An ESPHome display for Energy in the house (solar, battery, etc) | [anthony-spruyt](https://github.com/anthony-spruyt) (#) | | [Github](https://github.com/anthony-spruyt/ESPHOME-ESP32_CYD_V2-SmartEnergyMeter) | |
+| Navi Phone | Relica of the Mobile Phones used int the anime Serial Experments Lain | [Aquafrostbyte](https://github.com/AquaFrostByte) (#) | A Sd card is required, Speaker and Wifi is optional | [Github](https://github.com/AquaFrostByte/Navi-Phone) | |
+| OASMan | Open-source Air Suspension Management - Worlds first DIY Digital Air suspension controller for your car! | [gopro_2027](https://github.com/gopro2027/) | Ideally you would build the manifold and install it in your car, but if you just want to test the connection you can use an original esp32 dev board and flash the manifold code through platformio. We also have a [3d printable case](https://github.com/gopro2027/ArduinoAirSuspensionController/blob/main/3d%20Prints/other/3.2%20inch%20screen%20case/3.2%20inch%20CYD%20screen%20container%20v19%20-%20gopro_2027's%20design.stl) | [Github](https://github.com/gopro2027/ArduinoAirSuspensionController) | [Webflash](https://oasman.dev/oasman/flash/) |
+| Sonos Remote Control | Use your Sonos Speakers as Internet Radio with Station Buttons | Florian Lenz | https://github.com/SpringTideSystems | [GitHub](https://github.com/SpringTideSystems/CYD_Sonos-RemoteControl) | |
+
+(\#) = Project not added by original author
+
+## Adding a project
+
+If you have a project that you would like to add, please feel free to add it to the list!
+
+New projects should be added to bottom of the list.
+
+Some rules:
+
+- Project must be open source
+- Project must be functional - It's ok for it to not be finished, but it should do what it says!

firmware/cyd_esp32_2432s028/docs/README.md

@@ -0,0 +1,114 @@
+# ESP32-Cheap-Yellow-Display
+
+There is an ESP32 with a built in 320 x 240 2.8" LCD display with a touch screen called the "ESP32-2432S028R", since this doesn't roll of the tongue, I propose it should be renamed the "Cheap Yellow Display" or CYD for short. This display is only about $15 delivered so I think it's really good value.
+
+![image](https://github.com/witnessmenow/ESP32-Cheap-Yellow-Display/assets/1562562/76c3d481-2523-4b6f-881c-2e29f9368cd0)
+
+## Features
+
+The CYD has the following features:
+
+- ESP32 (With Wifi and Bluetooth)
+- 320 x 240 LCD Display (2.8")
+- Touch Screen (Resistive)
+- USB for powering and programming
+- SD Card Slot, LED and some additional pins broken out
+
+## Who is it good for?
+
+I think it's useful for the following types of people:
+
+- **People just getting started with working hardware** - as everything is already connected, there is no soldering or additional components required
+- **People who are familiar with working with hardware, but are lazy** - (like me) Sometimes you just want to build a project without having to assemble any hardware
+- **People who aren't really looking to learn anything, but just want to build some cool things** - More about this later.
+
+## What is the purpose of this page?
+
+So this is pretty nice hardware and a cheap price, but the software instructions/support around it is pretty poor. Just a single link to a zip file on a random website.
+
+A couple of years ago I released the [ESP32 Trinity](https://github.com/witnessmenow/ESP32-Trinity), which is an open source ESP32 board for controlling Matrix panels. I think the main benefit people get out of the work I did on the Trinity is not the hardware, but the documentation, example code and ready to go projects.
+
+I'm no longer creating hardware products, but I think it would be interesting if we could create the same kind of community around this display, where people can share examples and projects made for this display.
+
+## How do I know if a display is a CYD?
+![CYD decision tree](http://www.plantuml.com/plantuml/png/RP0nJyCm48Nt_8gZNIb3fge3LD2b2q92235UamDRE7PaNuhyxxda7DGgJBs-zxtSE-yJO-IXSzKD6-e8UeVMLyQs1DJrdA6br4JRims-4fW9LiS4bY6JS-47qBTWC052QvEayyCAvA-wS-8vi01F7mS8SVevOxJeUK9zu55QzzP_Nw-exxPmz8tHJzRRsJq4cdo3Pu98oIQsCd4O6WDIbyXF4LN-JNMsYG7UNXyXUAUTLHDfqVeMJWClUfSPrY_OOyPtO_ivUPcfnoMV3iyXJh4cj_MGJd8lEleQkvQKi9TYUT_DvbukXnraIfTQURMT39Nu8kcrXInIwQYO-gCyNwgm6al-ZneTNIRqjLokqS2UV3jqxXS0)
+
+## Where to buy?
+
+Buy from wherever works out cheapest for you:
+
+- [Aliexpress\*](https://s.click.aliexpress.com/e/_DkSpIjB)
+- [Aliexpress\*](https://s.click.aliexpress.com/e/_DkcmuCh)
+- [Aliexpress](https://www.aliexpress.com/item/1005004502250619.html)
+- [Makerfabs](https://www.makerfabs.com/sunton-esp32-2-8-inch-tft-with-touch.html) - Seems to come with a 16GB SD card. Makerfabs also stock my [ESP32 Trinity](https://github.com/witnessmenow/ESP32-Trinity) (NOTE there will be import due in the EU from makerfabs)
+
+\* = Affiliate Link
+
+## Getting Started With Your CYD
+
+For details on how to get started with your CYD, please check out the [Setup and Configuration](/SETUP.md) page
+
+## Code Examples
+
+### The Basics
+
+A collection of examples demonstrating how to use the different features of the CYD, this is a good place to get started. [Check them out here.](/Examples/Basics)
+
+### Alternative Display Libraries
+
+The basics examples are based on the TFT_eSPI display library, but the CYD also works with other display libraries too. Here is some example code if you prefer to use an alternative Arduino library. [Check them out here.](/Examples/AlternativeLibraries)
+
+### ESPHome
+
+Some examples for using the CYD in ESPHome. [Check them out here.](/Examples/ESPHome)
+
+## Additional Info and Links
+
+### Discord
+
+Join the CYD discussion on [my Discord channel](https://discord.gg/nnezpvq)
+
+### 3DPrinting
+
+Some examples of 3D printed stands and cases. [Check them out here.](/3dModels)
+
+### Pin Information
+
+[This page](/PINS.md) contains information about what pins are used where, and what ones are free to use.
+
+### Add-ons
+
+[This page](/ADDONS.md) contains information about additional hardware add-ons that can add functionality to your CYD
+
+### Troubleshooting
+
+[This page](/TROUBLESHOOTING.md) contains information about how to troubleshoot your CYD device
+
+### Hardware Mods
+
+[This page](/Mods/README.md) contains information about some hardware mods that can be performed on the CYD to improve or change some of its functionality
+
+### Media and Video Mentions
+
+[This page](/MEDIA.md) lists any times the CYD project was mentioned somewhere!
+
+## License Info
+
+This project is licensed as MIT as per the [license file](/LICENSE)
+
+The one exception to this is the [OriginalDocumentation](/OriginalDocumentation/) folder, that I do not have the right to license
+
+## Other Languages
+
+Some members of the community have ported some of this information to other languages! 
+
+Please note: I can't gaurantee the accuracy of the translation, how up to date they are or the content on them in general.
+
+- [French / Française](https://github.com/usini/ESP32-Cheap-Yellow-Display-Documentation-FR)
+- [German / Deutsch](https://github.com/paelzer/ESP32-Cheap-Yellow-Display-Documentation-DE)
+
+If you would like to contribure a translation, please name the repo with the language name or code in the repo name and you can link it here.
+
+## Help Support what I do!
+
+[If you enjoy my work, please consider becoming a Github sponsor!](https://github.com/sponsors/witnessmenow/)

firmware/cyd_esp32_2432s028/docs/SETUP.md

@@ -0,0 +1,39 @@
+# Setup and Configuration options
+
+This page will cover the basics of setting up the CYD
+
+## Hardware Setup
+
+There really is nothing to setup here, just connect the CYD to a computer using a micro USB cable (it even comes with one)
+
+## Software Setup
+
+The driver needs to be setup for uploading to the CYD, including webflashing projects. 
+
+### Driver
+
+The CYD uses the CH340 USB to UART chip. If you do not have a driver already installed for this chip you may need to install one. Check out [Sparkfun's guide for installation instruction](https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all)
+
+## Coding Setup
+
+Follow these instructions if you want to write new code for the CYD
+
+### Board definition
+
+You will need to have the ESP32 setup for your Arduino IDE, [instructions can be found here](https://docs.espressif.com/projects/arduino-esp32/en/latest/installing.html).
+
+You can then select basically any ESP32 board in the boards menu. (I usually use "ESP32 Dev Module", but it doesn't really matter)
+
+If you see errors uploading a sketch, try setting board upload speed to `115200`
+
+### Library Configuration
+
+The CYD can work with a selection of different libraries, but the main one this repo will focus on is [TFT_eSPI](https://github.com/Bodmer/TFT_eSPI) as it is a fairly popular library for working with these types of displays and there are lots of examples. 
+
+This can be installed from the library manager by searching for "TFT_eSPI".
+
+ > Note: After install of the library, copy the file [User_Setup.h](https://github.com/witnessmenow/ESP32-Cheap-Yellow-Display/blob/main/DisplayConfig/User_Setup.h) to the `libraries\TFT_eSPI` Arduino folder. This sets up the library for use with this display.
+
+### Examples
+
+I have provided examples for you to try out to get some ideas or inspiration. [Check them out here.](/Examples/)

firmware/cyd_esp32_2432s028/docs/TROUBLESHOOTING.md

@@ -0,0 +1,45 @@
+# First, Make sure it's a CYD!
+
+If you are having any issues, this is the first thing I would check! 
+
+The examples and information contained on this repo are for the **ESP32-2432S028** display only. The model number is written on the back of the display in gold writting, beside the speaker connector.
+
+# Display is not turning on
+
+If you are having issues getting the display working, the first thing I would try is [webflashing an existing project](/PROJECTS.md#projects-1). These will be known working code, and if it works correctly, it points to a software issue, not a hardware one.
+
+## If the webflash project displays something on the screen
+
+- Make sure you have put the [User_Setup.h](DisplayConfig/User_Setup.h) file in the correct location [as described here](/SETUP.md#library-configuration)
+- Pin 21 is the backlight pin, make sure you are not using it for something else in your sketch.
+
+## The webflash project doesn't display on screen
+
+- Make sure you are not connecting Pin 21 to anything. It is broken out on the connector labeled `P3`
+- Try a different USB supply and or cable
+- If nothing else worked, your CYD could be faulty. Contact the seller.
+
+# Display, Touch and SD card are not working at the same time
+
+The ESP32 offers two usable hardware SPI buses, but on the CYD each of display, touch and SD card use a different bus. To use all three devices at the same time, for one of them the SPI has to be "simulated" in software. Usually this is done for the touch device, since it doesn't require a high bandwidth. Therefor use a software SPI implementation like [XPT2046_Bitbang_Slim](https://github.com/TheNitek/XPT2046_Bitbang_Arduino_Library) and follow the [button example](https://github.com/witnessmenow/ESP32-Cheap-Yellow-Display/tree/main/Examples/Basics/8-Buttons)
+
+# Display is flickering
+
+- Try a different USB supply and or cable
+- Go through the [Display is not turning on](#display-is-not-turning-on) steps
+- If nothing else worked, your CYD could be faulty. Contact the seller.
+
+# Cannot upload
+- On Ubuntu and flavors disable or uninstall service `brltty` and make sure user is in group `dialout`
+
+# Automatic flash with esptool failed: Wrong boot mode detected (0x13)
+
+This is the well-known problem of flashing ESP32 through USB-UART converter, when DTR and RTS signals are used to switch the chip to the bootloader mode (with additional 2xNPN transistor digital protection logic). On some PC, OS, driver version it works, on another it doesn't:
+
+```
+A fatal error occurred: Failed to connect to ESP32: Wrong boot mode detected (0x13)! The chip needs to be in download mode. For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
+```
+
+The solution is to replace a capacitor between EN (RST) and GND from 0.1uF, installed on CYD, to something in range 1uF and 10uF.
+
+**NOTE:** In schematic, this is C4, but at least on Type-C version of CYD it is C5 actually.

firmware/cyd_esp32_2432s028/docs/cyd.md

@@ -0,0 +1,43 @@
+## What is a Cheap Yellow Display (CYD)?
+
+A CYD is a ESP32-2432S028, an ESP32 development board with a 2.8" display with a resistive touch screen,
+
+There are other boards with different sizes displays that look similar but **are not** a CYD. This isn't to try exclude anyone, but there so many different displays and types that it would be incredibly difficult and very confusing to support all of them.
+
+You can verify you have the correct board by checking the number on the back of the display.
+
+![image](https://github.com/witnessmenow/ESP32-Cheap-Yellow-Display/assets/1562562/d23bf84f-f34b-4814-b609-87c359d6334e)
+
+## My CYD has two USB ports
+
+The original CYD only has a micro USB port, but there is a device that is also labelled a _ESP32-2432S028_ that has two USB ports, one micro USB and one USB-C.
+
+Having an additional USB port would be a minor problem if that was the only difference, but unfortunately the display also works differently, the colours are inverted on the display.
+
+It can be fixed in a couple of ways:
+
+- Use platformio - The examples on the Github have all been updated so they can be used with platformio, and you can simply select CYD or CYD2USB and it will just work
+- Use the [CYD2USB specific User_setup.h](/DisplayConfig/CYD2USB/) that is on the repo, you can now use all the examples like normal
+- Invert the display at the code level using the `tft.invertDisplay(1);` method
+
+### The USB-C port doesn't work
+
+The USB-C port has a flaw in it, it doesn’t have the resistors on the CC lines. This means it will not work with USB-C to USB-C cables. If your computer only has USB-C ports, you can use it through a USB-C to USB-A adaptor.
+
+### The Display doesn't look as good 
+
+There seems to be a gamma issue with the CYD2USB (I don't even know what gamma is)
+
+Adding this to the code seems to help
+
+```
+tft.writecommand(ILI9341_GAMMASET); //Gamma curve selected
+tft.writedata(2);
+delay(120);
+tft.writecommand(ILI9341_GAMMASET); //Gamma curve selected
+tft.writedata(1);
+```
+
+
+
+

firmware/cyd_esp32_2432s028/main/key_derivation.c

@@ -10,9 +10,9 @@
 #include "esp_log.h"
 
 #include "mbedtls/md.h"
-#include "mbedtls/ed25519.h"
 #include "mbedtls/ecp.h"
 #include "mbedtls/pk.h"
+#include "psa/crypto.h"
 
 #include "secp256k1.h"
 #include "secp256k1_extrakeys.h"
@@ -381,18 +381,33 @@ int derive_ed25519_key(const uint8_t seed[64], uint32_t index,
         return -1;
     }
 
-    /* The SLIP-0010 derived 32 bytes IS the ed25519 private key.
-     * Use mbedtls to derive the public key. */
+    /* The SLIP-0010 derived 32 bytes IS the ed25519 private key. */
     memcpy(privkey, derived_seed, 32);
 
-    /* mbedtls_ed25519_make_public: derive pub from priv */
-    /* Note: mbedtls ed25519 API may vary by version. The ESP-IDF mbedtls
-     * component provides mbedtls_ed25519_make_public (or via the PK API).
-     * We use the low-level function if available. */
-    int ret = mbedtls_ed25519_make_public((unsigned char *)pubkey, 32,
-                                           (const unsigned char *)privkey, 32);
-    if (ret != 0) {
-        ESP_LOGE(KD_TAG, "ed25519 make_public failed: %d", ret);
+    /* Derive the ed25519 public key via PSA crypto (IDF v5.x mbedtls has no
+     * mbedtls_ed25519_make_public). Import the private key, export the pub. */
+    psa_status_t status;
+    psa_key_id_t key_id = 0;
+    psa_key_attributes_t attrs = PSA_KEY_ATTRIBUTES_INIT;
+    size_t pub_len = 0;
+
+    psa_crypto_init();
+    psa_set_key_type(&attrs, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_TWISTED_EDWARDS));
+    psa_set_key_bits(&attrs, 255);
+    psa_set_key_usage_flags(&attrs, PSA_KEY_USAGE_EXPORT | PSA_KEY_USAGE_SIGN_MESSAGE);
+    psa_set_key_algorithm(&attrs, PSA_ALG_PURE_EDDSA);
+
+    status = psa_import_key(&attrs, privkey, 32, &key_id);
+    if (status != PSA_SUCCESS) {
+        ESP_LOGE(KD_TAG, "ed25519 psa_import failed: %d", (int)status);
+        memset(derived_seed, 0, sizeof(derived_seed));
+        memset(privkey, 0, 32);
+        return -1;
+    }
+    status = psa_export_public_key(key_id, pubkey, 32, &pub_len);
+    psa_destroy_key(key_id);
+    if (status != PSA_SUCCESS || pub_len != 32) {
+        ESP_LOGE(KD_TAG, "ed25519 psa_export_public failed: %d", (int)status);
         memset(derived_seed, 0, sizeof(derived_seed));
         memset(privkey, 0, 32);
         return -1;
@@ -402,20 +417,64 @@ int derive_ed25519_key(const uint8_t seed[64], uint32_t index,
     return 0;
 }
 
+/* ed25519 sign via PSA (PureEdDSA — signs the raw message, not pre-hashed). */
 int ed25519_sign32(const uint8_t privkey[32], const uint8_t msg32[32],
                    uint8_t sig64[64]) {
-    /* mbedtls_ed25519_sign: sign a message (not pre-hashed) */
-    int ret = mbedtls_ed25519_sign((unsigned char *)sig64, 64,
-                                    (const unsigned char *)msg32, 32,
-                                    (const unsigned char *)privkey, 32,
-                                    NULL, NULL);
-    if (ret != 0) {
-        ESP_LOGE(KD_TAG, "ed25519 sign failed: %d", ret);
+    return ed25519_sign_msg(privkey, msg32, 32, sig64);
+}
+
+int ed25519_sign_msg(const uint8_t privkey[32], const uint8_t *msg, size_t msg_len,
+                     uint8_t sig64[64]) {
+    psa_status_t status;
+    psa_key_id_t key_id = 0;
+    psa_key_attributes_t attrs = PSA_KEY_ATTRIBUTES_INIT;
+    size_t sig_len = 0;
+
+    psa_crypto_init();
+    psa_set_key_type(&attrs, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_TWISTED_EDWARDS));
+    psa_set_key_bits(&attrs, 255);
+    psa_set_key_usage_flags(&attrs, PSA_KEY_USAGE_SIGN_MESSAGE);
+    psa_set_key_algorithm(&attrs, PSA_ALG_PURE_EDDSA);
+
+    status = psa_import_key(&attrs, privkey, 32, &key_id);
+    if (status != PSA_SUCCESS) {
+        ESP_LOGE(KD_TAG, "ed25519 sign psa_import failed: %d", (int)status);
+        return -1;
+    }
+    status = psa_sign_message(key_id, PSA_ALG_PURE_EDDSA,
+                              msg, msg_len, sig64, 64, &sig_len);
+    psa_destroy_key(key_id);
+    if (status != PSA_SUCCESS || sig_len != 64) {
+        ESP_LOGE(KD_TAG, "ed25519 psa_sign_message failed: %d", (int)status);
         return -1;
     }
     return 0;
 }
 
+int ed25519_verify_msg(const uint8_t *sig, size_t sig_len,
+                       const uint8_t *msg, size_t msg_len,
+                       const uint8_t pubkey[32]) {
+    psa_status_t status;
+    psa_key_id_t key_id = 0;
+    psa_key_attributes_t attrs = PSA_KEY_ATTRIBUTES_INIT;
+
+    psa_crypto_init();
+    psa_set_key_type(&attrs, PSA_KEY_TYPE_ECC_PUBLIC_KEY(PSA_ECC_FAMILY_TWISTED_EDWARDS));
+    psa_set_key_bits(&attrs, 255);
+    psa_set_key_usage_flags(&attrs, PSA_KEY_USAGE_VERIFY_MESSAGE);
+    psa_set_key_algorithm(&attrs, PSA_ALG_PURE_EDDSA);
+
+    status = psa_import_key(&attrs, pubkey, 32, &key_id);
+    if (status != PSA_SUCCESS) {
+        ESP_LOGE(KD_TAG, "ed25519 verify psa_import failed: %d", (int)status);
+        return -1;
+    }
+    status = psa_verify_message(key_id, PSA_ALG_PURE_EDDSA,
+                                msg, msg_len, sig, sig_len);
+    psa_destroy_key(key_id);
+    return (status == PSA_SUCCESS) ? 0 : -1;
+}
+
 /* --- x25519 --- */
 
 int derive_x25519_key(const uint8_t seed[64], uint32_t index,
@@ -429,10 +488,10 @@ int derive_x25519_key(const uint8_t seed[64], uint32_t index,
         0u | BIP32_HARDENED_FLAG,
     };
     uint8_t derived_seed[32];
-    mbedtls_ecp_group grp;
-    mbedtls_mpi d;
-    mbedtls_ecp_point Q;
-    int ret;
+    psa_status_t status;
+    psa_key_id_t key_id = 0;
+    psa_key_attributes_t attrs = PSA_KEY_ATTRIBUTES_INIT;
+    size_t pub_len = 0;
 
     if (seed == NULL || privkey == NULL || pubkey == NULL) {
         return -1;
@@ -443,54 +502,30 @@ int derive_x25519_key(const uint8_t seed[64], uint32_t index,
     }
 
     /* The SLIP-0010 derived 32 bytes IS the x25519 private key.
-     * Clamp it per RFC 7748 and derive the public key via mbedtls ECDH. */
+     * PSA imports it and exports the public key (PSA handles clamping). */
     memcpy(privkey, derived_seed, 32);
     memset(derived_seed, 0, sizeof(derived_seed));
 
-    /* x25519 clamping: priv[0] &= 248, priv[31] &= 127, priv[31] |= 64 */
-    privkey[0] &= 248;
-    privkey[31] &= 127;
-    privkey[31] |= 64;
+    psa_crypto_init();
+    psa_set_key_type(&attrs, PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_FAMILY_MONTGOMERY));
+    psa_set_key_bits(&attrs, 255);
+    psa_set_key_usage_flags(&attrs, PSA_KEY_USAGE_EXPORT | PSA_KEY_USAGE_DERIVE);
+    psa_set_key_algorithm(&attrs, PSA_ALG_ECDH);
 
-    mbedtls_ecp_group_init(&grp);
-    mbedtls_mpi_init(&d);
-    mbedtls_ecp_point_init(&Q);
-
-    ret = mbedtls_ecp_group_load(&grp, MBEDTLS_ECP_DP_CURVE25519);
-    if (ret != 0) {
-        ESP_LOGE(KD_TAG, "x25519 group load failed: %d", ret);
-        goto cleanup;
+    status = psa_import_key(&attrs, privkey, 32, &key_id);
+    if (status != PSA_SUCCESS) {
+        ESP_LOGE(KD_TAG, "x25519 psa_import failed: %d", (int)status);
+        memset(privkey, 0, 32);
+        return -1;
     }
-
-    ret = mbedtls_mpi_read_binary_le(d, privkey, 32);
-    if (ret != 0) {
-        ESP_LOGE(KD_TAG, "x25519 mpi read failed: %d", ret);
-        goto cleanup;
+    status = psa_export_public_key(key_id, pubkey, 32, &pub_len);
+    psa_destroy_key(key_id);
+    if (status != PSA_SUCCESS || pub_len != 32) {
+        ESP_LOGE(KD_TAG, "x25519 psa_export_public failed: %d", (int)status);
+        memset(privkey, 0, 32);
+        return -1;
     }
-
-    ret = mbedtls_ecp_mul(&grp, &Q, d, &grp.G, NULL, NULL);
-    if (ret != 0) {
-        ESP_LOGE(KD_TAG, "x25519 ecp_mul failed: %d", ret);
-        goto cleanup;
-    }
-
-    /* Serialize the public key as raw 32 bytes (little-endian) */
-    {
-        size_t olen = 0;
-        ret = mbedtls_ecp_point_write_binary(&grp, &Q,
-                                              MBEDTLS_ECP_PF_COMPRESSED,
-                                              &olen, pubkey, 32);
-        if (ret != 0 || olen != 32) {
-            ESP_LOGE(KD_TAG, "x25519 pub serialize failed: %d", ret);
-            ret = -1;
-        }
-    }
-
-cleanup:
-    mbedtls_ecp_group_free(&grp);
-    mbedtls_mpi_free(&d);
-    mbedtls_ecp_point_free(&Q);
-    return (ret == 0) ? 0 : -1;
+    return 0;
 }
 
 /* --- ML-DSA-65 --- */

firmware/cyd_esp32_2432s028/main/key_derivation.h

@@ -17,12 +17,21 @@ int schnorr_sign32(const uint8_t privkey[32], const uint8_t msg32[32], uint8_t s
 int derive_ed25519_key(const uint8_t seed[64], uint32_t index,
                        uint8_t privkey[32], uint8_t pubkey[32]);
 
-/* Signs a 32-byte message digest with ed25519.
+/* Signs a 32-byte message digest with ed25519 (PureEdDSA, raw message).
  * sig: 64-byte ed25519 signature
  * Returns 0 on success, -1 on error. */
 int ed25519_sign32(const uint8_t privkey[32], const uint8_t msg32[32],
                    uint8_t sig64[64]);
 
+/* Signs a variable-length message with ed25519 (PureEdDSA). */
+int ed25519_sign_msg(const uint8_t privkey[32], const uint8_t *msg, size_t msg_len,
+                     uint8_t sig64[64]);
+
+/* Verifies an ed25519 signature over a variable-length message. */
+int ed25519_verify_msg(const uint8_t *sig, size_t sig_len,
+                       const uint8_t *msg, size_t msg_len,
+                       const uint8_t pubkey[32]);
+
 /* --- x25519 (age encryption / key agreement) --- */
 /* Derives an x25519 keypair from the mnemonic seed using SLIP-0010
  * all-hardened derivation: m/44'/102002'/<n>'/0'/0'

firmware/cyd_esp32_2432s028/sdkconfig.defaults

@@ -8,3 +8,8 @@ CONFIG_PARTITION_TABLE_FILENAME="partitions.csv"
 CONFIG_FREERTOS_HZ=1000
 CONFIG_ESP_MAIN_TASK_STACK_SIZE=16384
 CONFIG_COMPILER_OPTIMIZATION_SIZE=y
+
+# PSA crypto for ed25519 sign/verify (IDF v5.x mbedtls has no mbedtls_ed25519_*).
+CONFIG_MBEDTLS_PSA_CRYPTO_C=y
+# Curve25519 / Ed25519 ECP domain parameter (already enabled, kept for clarity).
+CONFIG_MBEDTLS_ECP_DP_CURVE25519_ENABLED=y

firmware/fpga_signer/README.md

@@ -0,0 +1,192 @@
+# n_signer FPGA Signing Core
+
+**Status:** Concept — brainstorming. No plan yet.
+
+An FPGA-based secp256k1 signing core that provides the **maximum physical
+security** possible for Nostr signing: constant-time crypto (no instruction
+timing leakage), key material in FPGA fabric (no bus access to the key), and no
+firmware (no malware injection surface). The FPGA is a **signing oracle** — a
+small, auditable hardware module that does one thing (secp256k1 schnorr/ECDSA
+signing) with side-channel resistance that software on an MCU cannot match.
+
+## The secure element gap
+
+Commercial secure elements (NXP JCOP, Infineon, Microchip ATECC) support NIST
+curves (P-256, P-384) and RSA, but **not secp256k1** — the smart card industry
+standardized on NIST curves, and secp256k1 was treated as a "Bitcoin curve"
+that didn't get hardware support. This is why every Nostr/Bitcoin hardware
+wallet (Coldcard, Ledger, Trezor, Keystone) uses a **general-purpose MCU**
+running software secp256k1, not a secure element.
+
+An FPGA fills this gap: it gives us **hardware-level secp256k1** without relying
+on a secure element vendor to support the curve. We write the secp256k1 core
+ourselves in Verilog, with full control over the timing, the key storage, and
+the side-channel resistance.
+
+## Why an FPGA
+
+| Property | MCU (software) | FPGA (hardware) |
+|---|---|---|
+| Timing leakage | Branch prediction, cache, instruction timing | **None** — fixed datapath, every op takes the same cycles |
+| Key storage | RAM (accessible via bus/debug) | **FPGA fabric / BRAM** (no external bus access) |
+| Firmware attacks | OS, USB stack, BT stack = injection surface | **No firmware** — bitstream is the entire program |
+| Debug access | JTAG/SWD can read RAM | **No debug path to key** if not routed |
+| Auditability | Large codebase (thousands of lines of C) | **Small Verilog core** (~2000 lines, auditable) |
+| PQ crypto | Yes (software) | No (too complex for FPGA) |
+
+## Architecture: hybrid FPGA + MCU
+
+The practical design is a **two-chip hybrid**: the FPGA is the signing oracle,
+the MCU handles the protocol/UI/transport. The MCU sends a message hash + key
+index to the FPGA over SPI; the FPGA signs with the key in fabric; the FPGA
+returns the 64-byte signature. The private key never leaves the FPGA.
+
+```mermaid
+flowchart TD
+    subgraph Host_Side
+        Host[Host: laptop/phone<br/>n_signer client]
+    end
+    subgraph Signer_Device
+        MCU[MCU: RP2040 or nRF52840<br/>protocol + UI + transport<br/>PQ crypto in software]
+        FPGA[FPGA: iCE40-UP5K<br/>secp256k1 signing core<br/>ed25519 signing core<br/>SHA-256/512 cores<br/>key in BRAM]
+        Display[OLED / e-paper display]
+        Buttons[approve / deny buttons]
+    end
+    Host -->|USB / IR / NFC / BLE| MCU
+    MCU -->|SPI: msg_hash + key_index| FPGA
+    FPGA -->|SPI: 64-byte signature| MCU
+    MCU --> Display
+    Buttons --> MCU
+    MCU -->|response| Host
+```
+
+### Division of labor
+
+| Function | Chip | Notes |
+|---|---|---|
+| Transport (USB/IR/NFC/BLE) | MCU | Ported from CYD/Teensy firmware |
+| JSON-RPC dispatch | MCU | Ported from `handle_request()` |
+| Auth envelope verify | MCU | secp256k1 schnorr verify (software) |
+| Approval UI (display + buttons) | MCU | Ported from CYD UI |
+| Mnemonic entry | MCU | BIP-39 wordlist + entry UI |
+| BIP-32 / SLIP-0010 key derivation | **FPGA** | SHA-512 HMAC core + derivation FSM |
+| secp256k1 schnorr sign | **FPGA** | Constant-time scalar multiply + schnorr |
+| secp256k1 ECDSA sign | **FPGA** | Same scalar multiply + RFC 6979 nonce |
+| ed25519 sign | **FPGA** | Curve25519 arithmetic core |
+| x25519 ECDH | **FPGA** | Same curve as ed25519 |
+| SHA-256 | **FPGA** | Hardware core (~1000 LUTs) |
+| SHA-512 | **FPGA** | Hardware core (~2000 LUTs) — needed for BIP-32 |
+| HMAC-SHA-256 | **FPGA** | SHA-256 core + FSM — for the `derive` verb |
+| NIP-04 / NIP-44 encryption | MCU | AES + ChaCha20 in software |
+| ML-DSA-65 / SLH-DSA-128s / ML-KEM-768 | MCU | PQClean in software (too complex for FPGA) |
+| nostr_mine_event (PoW) | MCU | SHA-256 hash loop in software (or offload to FPGA) |
+
+### Key storage in the FPGA
+
+The mnemonic seed (64 bytes) is loaded into the FPGA's BRAM at boot (sent by
+the MCU after the user enters the mnemonic). The FPGA derives secp256k1/ed25519/
+x25519 keys on demand using its SHA-512 + modular arithmetic cores. The derived
+private keys live in FPGA registers/BRAM and are **never readable from the SPI
+interface** — the SPI interface only accepts "sign this hash with key index N"
+commands and returns signatures. There is no "read key" command.
+
+This is the key security property: **the private key is physically unreachable
+from any external interface.** On an MCU, the key is in RAM and can be read via
+JTAG/SWD or a firmware exploit. On the FPGA, the key is in fabric and there is
+no path to it.
+
+## FPGA board options
+
+| Board | FPGA | LUTs | Toolchain | Price | Notes |
+|---|---|---|---|---|---|
+| **iCE40-UP5K** (e.g. iCEBreaker, Fomu) | iCE40UP5K | 5,300 | **Yosys + nextpnr** (open-source) | ~$15-20 | Best DIY choice. Open-source toolchain, DSP blocks, 128 KB BRAM, SPI flash. |
+| **Gowin Tang Nano 9K** | GW1NR-9 | 8,640 | Yosys + nextpnr (open-source) | ~$8 | Cheapest. Newer open-source support. |
+| **Lattice ECP5** (OrangeCrab, ULX3S) | LFE5U-12F / 25F / 45F | 12K-45K | Yosys + nextpnr (open-source) | ~$30-50 | More room. Supports **bitstream encryption** (important for production). |
+| **Xilinx Artix-7** (Arty A7) | XC7A35T | 33,280 | Vivado (proprietary) | ~$100 | Professional. Overkill for a signer. |
+
+**Recommendation: Lattice iCE40-UP5K for prototyping, ECP5 for production.**
+The iCE40 has the most mature open-source toolchain (Yosys + nextpnr) and is
+cheap. The ECP5 adds bitstream encryption (prevents bitstream cloning) for a
+production device.
+
+## The secp256k1 core (the hard part)
+
+The secp256k1 signing core is the main development effort. It needs:
+
+1. **256-bit modular arithmetic** over the secp256k1 prime field (p = 2²⁵⁶ - 2³² - 977):
+   - Modular add, subtract, multiply (Montgomery multiplication for performance)
+   - Modular inversion (Fermat's little theorem: a^(p-2) mod p, or extended Euclidean)
+2. **Point operations** on the secp256k1 curve (y² = x³ + 7):
+   - Point addition (Jacobian coordinates)
+   - Point doubling
+   - Scalar multiplication (constant-time double-and-add, no conditional branches)
+3. **Schnorr sign** (BIP-340):
+   - Deterministic nonce: k = HMAC-SHA256(d, x) where d is the key, x is the message hash
+   - R = k·G (point multiplication)
+   - e = tagged hash(R.x || P || m) (SHA-256)
+   - s = (k + e·x) mod n (scalar multiply + modular add)
+   - Signature = (R.x, s)
+4. **ECDSA sign** (for the `scheme:"ecdsa"` option):
+   - RFC 6979 deterministic nonce: k = HMAC-SHA256(x, m) with rejection sampling
+   - R = k·G
+   - r = R.x mod n
+   - s = k⁻¹ · (m + r·x) mod n
+   - Signature = (r, s)
+
+**Estimated size:** ~2000-5000 LUTs for the modular arithmetic + point
+multiplication + schnorr/ECDSA FSM. Fits comfortably in an iCE40-UP5K (5,300
+LUTs) alongside the SHA-256/512 cores and the SPI interface.
+
+**Estimated sign time:** ~1-5 ms at 12 MHz (iCE40-UP5K typical clock). The
+bottleneck is the 256-bit modular multiplication (~0.5-2 ms per multiply, ~256
+multiplies per scalar multiplication). This is **much faster than software**
+(the CYD's software schnorr sign takes ~10-50 ms).
+
+## Open questions
+
+- **Pure FPGA vs hybrid?** A pure-FPGA signer (no MCU) would implement the
+  entire dispatch + transport + UI in Verilog. This is extremely secure but
+  very hard to build (JSON parsing in Verilog is painful). The hybrid (FPGA
+  signing oracle + MCU protocol) is practical and still gives the key-isolation
+  benefit. **Lean toward hybrid.**
+- **Which MCU?** RP2040 (cheap, no WiFi) or nRF52840 (low power, NFC, BLE)?
+  This determines the transport options (USB, IR, NFC, BLE).
+- **Bitstream security:** iCE40 doesn't support bitstream encryption. If an
+  attacker reads the SPI flash, they get the bitstream (but not the key — the
+  key is loaded at runtime by the MCU, not stored in the bitstream). For
+  production, use ECP5 with bitstream encryption.
+- **Key loading:** the MCU sends the mnemonic seed to the FPGA at boot over
+  SPI. Is this SPI transfer vulnerable to sniffing? It happens once, at boot,
+  inside the device. If the device is physically sealed, the SPI bus is not
+  accessible. For higher security, the FPGA could derive the key from the
+  mnemonic internally (the MCU sends the mnemonic string, the FPGA does
+  PBKDF2-HMAC-SHA512 + BIP-32 derivation in hardware).
+- **ed25519 core:** worth implementing, or secp256k1-only? ed25519 is the same
+  field size (256-bit) but a different curve (Curve25519 vs secp256k1). The
+  modular arithmetic is similar but the curve operations differ. Adding
+  ed25519 roughly doubles the core size.
+- **Open-source secp256k1 FPGA cores:** are there existing Verilog secp256k1
+  cores we can reuse or adapt? (There are Bitcoin mining cores, but those do
+  double-SHA256, not ECDSA. Academic ECDSA-on-FPGA papers exist but the code
+  is rarely open-sourced. We'd likely write the core from scratch.)
+
+## Comparison to the other concepts
+
+| | FPGA signer (hybrid) | MCU-only (CYD/Teensy) | Secure element |
+|---|---|---|---|
+| secp256k1 side-channel resistance | **Best** (constant-time, key in fabric) | Medium (software, timing leakage) | N/A (no secp256k1 support) |
+| Key isolation | **Best** (no bus access to key) | Low (RAM, JTAG/SWD accessible) | Best (tamper-resistant) |
+| Firmware attack surface | **Minimal** (no firmware on FPGA) | Large (OS, USB, BT stacks) | Minimal (fixed function) |
+| PQ crypto | On MCU (software) | On MCU (software) | N/A |
+| Development effort | **High** (Verilog secp256k1 core) | Low (port existing C code) | High (NDA + Java Card) |
+| Cost | ~$15 FPGA + ~$4 MCU = ~$20 | ~$4-27 (MCU only) | ~$3-5 (chip only) |
+| Auditability | **High** (small Verilog core, open toolchain) | Medium (large C codebase) | Low (proprietary, NDA) |
+
+## Next steps
+
+- Decide: hybrid (FPGA + MCU) vs pure FPGA
+- Decide: iCE40-UP5K (prototype) vs ECP5 (production)
+- Decide: secp256k1-only vs secp256k1 + ed25519
+- Survey existing open-source secp256k1 / ECDSA FPGA cores
+- Write a Verilog secp256k1 modular arithmetic core (the foundation)
+- Write a plan (similar to [`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md))

firmware/ir_airgap_signer/README.md

@@ -0,0 +1,149 @@
+# n_signer IR Air-Gap Signer
+
+**Status:** Concept — brainstorming. No plan yet.
+
+A hardware signer that communicates with the host via **infrared light** —
+line-of-sight, short-range, physically directional. The signer never touches
+the host electrically: no wire, no radio, no shared ground. The only channel
+is modulated light through air. A small **USB receiver dongle** on the host
+decodes the IR signal and presents it as a CDC-ACM serial port.
+
+This is the strongest air-gap model in the n_signer family: the signer is
+electrically isolated from the host, and the receiver dongle is a dumb
+IR-to-serial bridge with no crypto, no keys, and ~200 lines of auditable
+firmware.
+
+## Concept
+
+```mermaid
+flowchart LR
+    Host[Host: laptop<br/>n_signer client] -->|USB CDC| Dongle[USB IR receiver dongle<br/>RP2040 + IR receiver]
+    Dongle -->|IR light<br/>line-of-sight| Signer[IR signer<br/>RP2040 + OLED + buttons]
+    Signer -->|approve/deny button| User[User]
+    Signer -->|IR light response| Dongle
+    Dongle -->|USB CDC| Host
+```
+
+The signer speaks the same algorithm-based API as the host and the CYD/Teensy
+firmware ([`README.md`](../../README.md) §4). The auth envelope (kind 27235)
+protects the IR wire. The receiver dongle is a transparent byte pipe — it has
+no knowledge of the protocol, no keys, and no state beyond the IR-to-USB
+bridge.
+
+## Why IR
+
+- **True air-gap** — the signer is electrically isolated from the host. No wire,
+  no radio, no shared ground. Host-side malware cannot reach the signer's
+  firmware through the communication channel.
+- **Line-of-sight required** — you point the signer at the receiver. An attacker
+  would need to be in the same room, in the line of sight, with their own IR
+  transmitter. Much smaller attack surface than BT (which broadcasts
+  omnidirectionally to ~10 m).
+- **Dumb dongle** — the USB receiver is a simple IR-to-serial bridge. ~200
+  lines of firmware, no crypto, no keys, fully auditable in an afternoon. If
+  compromised, it can only MITM the IR stream (which is already protected by the
+  auth envelope).
+- **No BT stack** — much smaller firmware attack surface on the signer. No
+  pairing, no GATT, no L2CAP, no SMP.
+- **Novel** — no hardware wallet uses IR for host communication. It's a
+  creative solution to the air-gap problem that avoids both the wire (USB) and
+  the radio (BT/NFC) attack surfaces.
+
+## Hardware (preliminary)
+
+### Signer
+
+| Component | Candidate | Notes |
+|---|---|---|
+| MCU | **RP2040** (Raspberry Pi Pico) | $4, Cortex-M0+ @ 133 MHz, 264 KB SRAM, no WiFi/BT (perfect for air-gap). Enough RAM for secp256k1 + ed25519. ML-DSA-65 fits (~6 KB heap). |
+| | or **nRF52840** | If you want NFC for mnemonic loading + lower power. |
+| IR transceiver | **38 kHz IR LED + TSOP38238** (raw async, 115200 baud, ~$1) | Simplest. ~11 KB/s. Fine for Nostr events (~500 bytes). Slow for PQ sigs (3-8 KB → 0.3-0.7 s). |
+| | or **TFBS4711 IrDA module** (~$2, up to 4 Mbps) | Faster (~400 KB/s) but harder to source + more complex protocol. |
+| Display | 0.96" SSD1306 OLED (I2C, ~$2) or 1.54" e-paper | Small is fine — shows "approve kind 1 from <caller>?" |
+| Input | 2-3 tactile buttons (approve/deny/back) | |
+| Power | Coin cell or small LiPo | RP2040 + OLED + IR = very low power |
+
+### USB receiver dongle
+
+| Component | Candidate | Notes |
+|---|---|---|
+| MCU | **RP2040** (Pico) or **ATmega32U4** (Arduino Micro) | $4-8. Native USB device. |
+| IR receiver | Matching TSOP38238 or IrDA module | Must match the signer's IR modulation. |
+| USB | Native USB CDC-ACM | Presents as `/dev/ttyACM0` to the host. |
+| Firmware | ~200 lines | Read IR → write USB CDC; read USB CDC → transmit IR. A dumb pipe. No crypto, no keys, no state. |
+
+## Throughput
+
+| IR mode | Baud | Throughput | sign_event (500 B req + 600 B resp) | ML-DSA-65 sign (3.3 KB sig) |
+|---|---|---|---|---|
+| Raw 38 kHz async | 115200 | ~11 KB/s | ~100 ms | ~300 ms |
+| Raw 38 kHz async | 230400 | ~23 KB/s | ~50 ms | ~150 ms |
+| IrDA | 4 Mbps | ~400 KB/s | ~3 ms | ~8 ms |
+
+**Recommendation:** start with raw 38 kHz IR at 115200 baud (simplest, cheapest,
+works with any IR LED + TSOP receiver). Upgrade to 230400 or IrDA if PQ
+signature throughput is a bottleneck.
+
+## Protocol
+
+The IR link is **half-duplex** — the signer and receiver take turns
+transmitting. The protocol is simple:
+
+1. Host sends JSON-RPC request → USB CDC → dongle transmits IR.
+2. Signer receives IR, parses the request, shows approval prompt.
+3. User approves/denies.
+4. Signer transmits IR response → dongle → USB CDC → host.
+
+The 4-byte big-endian length-prefix framing (same as the CYD/feather) works
+over IR as-is. The auth envelope protects against MITM on the IR stream.
+
+## Security model
+
+- **Electrical isolation:** the signer has no electrical connection to the host.
+  The IR link is a one-way-at-a-time optical channel.
+- **Line-of-sight:** an attacker must be in the same room, in the line of sight,
+  with their own IR transmitter. The auth envelope + approval prompt protect
+  against a MITM even if the attacker intercepts the IR stream.
+- **Dumb dongle:** the USB receiver has no crypto, no keys, no protocol
+  knowledge. It's a byte pipe. If compromised, it can only MITM the IR stream
+  (already protected by the auth envelope). The dongle's firmware is small
+  enough to audit in an afternoon.
+- **No radio:** no BT, no WiFi, no NFC (unless you add NFC for mnemonic loading).
+  The signer emits no RF — only modulated IR light when actively transmitting.
+
+## Open questions
+
+- **IR modulation:** raw 38 kHz async (simplest) vs IrDA (faster, more complex)?
+- **Mnemonic entry:** buttons (scroll BIP-39 words) vs NFC from phone vs
+  generate-on-device? On a 0.96" OLED, scrolling 2048 words is tedious but
+  secure.
+- **PQ crypto on RP2040:** 264 KB SRAM is enough for ML-DSA-65 but SLH-DSA-128s
+  is tight. May need to limit the PQ algorithm set.
+- **Dongle design:** separate RP2040 Pico, or integrate the IR receiver into a
+  custom PCB with a USB-A plug for a compact dongle?
+- **Range:** raw IR with an IR LED + TSOP38238 reaches ~1-2 m line-of-sight.
+  Enough for "point at the dongle on your desk" but not across a room.
+- **Bidirectional IR:** the signer needs both an IR LED (transmit) and a TSOP
+  receiver (receive). Two modules, or an IrDA transceiver module that does both?
+
+## Comparison to the BLE wearable signer
+
+| | IR air-gap | BLE wearable |
+|---|---|---|
+| Air-gap | **High (light, line-of-sight, ~1 m)** | Medium (radio, ~10 m, omnidirectional) |
+| Attack surface | **Small (no BT, dumb dongle)** | Large (BT stack) |
+| Host compatibility | Requires USB dongle | Universal (phones, laptops) |
+| Form factor | Handheld (point at dongle) | Wearable |
+| Throughput | ~11 KB/s (raw IR) or ~400 KB/s (IrDA) | ~250 KB/s (BLE 5) |
+| Novelty | **Novel (no hardware wallet uses IR)** | Conventional |
+| Cost | ~$10 signer + ~$8 dongle | ~$10-15 (nRF52840 + OLED) |
+
+## Next steps
+
+- Decide on IR modulation (raw 38 kHz vs IrDA)
+- Decide on MCU (RP2040 vs nRF52840)
+- Decide on mnemonic entry method
+- Decide on display (OLED vs e-paper)
+- Prototype the IR link: two RP2040 Picos + IR LEDs + TSOP38238, bidirectional
+  byte pipe at 115200 baud
+- Write a port plan (similar to [`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md))

firmware/nfc_card_signer/README.md

@@ -0,0 +1,192 @@
+# n_signer NFC Card / Ring Signer
+
+**Status:** Concept — open-ended brainstorming. No plan yet.
+
+A contactless signer in a **card or ring form factor** that is powered and
+communicates via **NFC (13.56 MHz)**. You place it on a reader (USB NFC reader
+or a phone); the reader's RF field powers the device and exchanges data. No
+battery, no wire, no radio beyond the 4 cm NFC zone.
+
+This directory also explores **passive RFID/NFC tag ideas** that don't do
+signing on-device — they store keys or seed material that a host reads and uses.
+
+---
+
+## Concept A: NFC-powered active signer (card with display + button)
+
+```mermaid
+flowchart LR
+    Host[Host: laptop/phone<br/>n_signer client] -->|USB or built-in NFC| Reader[NFC reader<br/>ACR122U or phone]
+    Reader -->|13.56 MHz RF field<br/>powers + communicates| Card[Signer card<br/>nRF52840 + e-paper + button]
+    Card -->|NFC response| Reader
+    Reader -->|USB| Host
+```
+
+The card has a tiny e-paper display + one button. The reader powers the card;
+the card shows the approval prompt on its own display; the user presses the
+button to approve; the card signs and sends the response over NFC. The card
+does not trust the reader for display — it shows what it's signing.
+
+### Hardware (preliminary)
+
+| Component | Candidate | Notes |
+|---|---|---|
+| MCU | **nRF52840** (WLCSP) | Cortex-M4, NFC-A tag mode built in, secp256k1/ed25519 in software. Needs a thin-film battery (not fully passive). |
+| | or **NXP JCOP 4** (Java Card) | Fully passive, hardware secp256k1, tamper-resistant. Requires NDA + Java Card applet. Not DIY. |
+| Display | 1.1" e-paper segment display | Shows "approve kind 1? caller: <hex>". Zero power when static. |
+| Input | One capacitive touch button | Press to approve, timeout = deny. |
+| Power | Thin-film battery (like payment cards with displays) + NFC harvesting | |
+| Antenna | Etched into flex PCB around card perimeter | Standard smart card manufacturing. |
+
+### Security
+
+- **Attack radius ~4 cm** — an attacker must touch your card with their reader.
+- **No emissions when not on a reader** — the card is invisible to remote attackers.
+- **Self-contained approval** — the card's display shows what it's signing. The reader can't lie.
+- **Physical possession = authorization** — same model as a payment card.
+
+### Build difficulty
+
+- **DIY prototype:** nRF52840 dev board + wire-wound NFC antenna + ACR122U reader + small OLED. Prove NFC-powered signing works.
+- **Production:** custom flex PCB + etched antenna + thin battery + e-paper segment. Standard smart card manufacturing, but not DIY.
+
+---
+
+## Concept B: NFC ring (tap-to-sign, no display)
+
+A ring with an NFC tag + MCU inside. No display, no button. You tap it on a
+reader; the reader displays the approval prompt; you tap again to confirm
+(two-tap protocol) or the ring signs immediately (single-tap, trusts the reader).
+
+### Hardware
+
+| Component | Candidate | Notes |
+|---|---|---|
+| MCU | Secure element (JCOP / Infineon) or nRF52840 (WLCSP) | Must be tiny (2×3 mm package). |
+| Power | **Fully passive** (harvested from reader) if using a secure element. nRF52840 needs a battery. |
+| Antenna | Coil wound into the ring body | Custom manufacturing. |
+| Display | **None** | No room. |
+| Input | **None** | Pure tap-to-sign. |
+
+### Security
+
+- **Two-tap protocol:** tap to receive the request, reader displays it, tap again to sign. Forces deliberate action but still trusts the reader's display.
+- **Single-tap:** anyone who taps your ring with a reader can sign. Only safe if the ring is always in your physical possession and the reader is trusted.
+- **No display = reader-trusted approval.** Weaker than Concept A but much more portable.
+
+### Build difficulty
+
+- **Very hard** — custom antenna winding, tiny chip placement, ring-form-factor PCB. Not DIY without specialized equipment.
+
+---
+
+## Concept C: Passive NFC tag that stores keys (no on-device signing)
+
+This is a fundamentally different idea: the tag **does not sign anything**. It
+stores key material (a mnemonic seed, a private key, or a derived key) that a
+host reads over NFC and uses to sign. The tag is a **portable key storage
+device**, not a signer.
+
+### How it would work
+
+1. The user taps the tag on a phone or USB NFC reader.
+2. The host reads the stored key material over NFC (ISO 14443 / NDEF).
+3. The host uses the key material to sign (the host runs the n_signer crypto).
+4. The tag is just storage — it has no MCU, no crypto, no battery.
+
+### What the tag stores (options)
+
+| Storage model | What's on the tag | Security | Notes |
+|---|---|---|---|
+| **Encrypted seed** | The mnemonic seed, encrypted with a passphrase (BIP-39 password). The host decrypts after the user types the passphrase. | Medium — if the tag is stolen, the attacker needs the passphrase. | Like an encrypted paper backup, but in NFC form. |
+| **Raw private key** | The secp256k1 private key (32 bytes), stored in the tag's EEPROM. | **Low** — anyone who reads the tag has the key. Only safe if the tag is PIN-protected (needs a secure element, not a dumb tag). | Like storing a private key on a USB stick. |
+| **NDEF URI** | A URI like `nostr:npub1...` (just the public key). The host uses it to identify which key to use (the actual private key is elsewhere). | High (it's just a pubkey) | Not a signer — just an identity token. |
+| **Shamir shard** | One share of a Shamir's Secret Sharing split of the seed. The tag holds 1 of N shares; you need M tags to reconstruct. | **High** — a single tag is useless. | Like a metal seed backup but in NFC form. Multiple tags = multiple shares. |
+| **HD wallet derivation path** | Just the derivation path + a reference to a master seed stored elsewhere. The tag tells the host *which* key to derive. | Medium | The tag is a pointer, not the key itself. |
+
+### Hardware
+
+| Component | Candidate | Notes |
+|---|---|---|
+| **NTAG215** (NXP) | 504 bytes user memory, no crypto, ~$0.10 | The cheapest option. Stores an encrypted seed or NDEF URI. No MCU. |
+| **NTAG424 DNA** (NXP) | 4 KB, AES-128, tamper detection, ~$0.50 | Has crypto — can do authenticated read (the host must present a key to read the data). Better security. |
+| **MIFARE DESFire EV3** | 32 KB, AES, secure applets, ~$1 | Smart card chip. Can store encrypted key material with PIN/mutual auth. |
+| **Java Card (JCOP)** | Full smart card, runs applets, ~$3-5 | Could run a "key storage" applet that only releases the seed after a PIN is verified on the host. |
+
+### Security analysis
+
+The **passive tag as key storage** is the weakest signer model (the host does
+the signing, so a compromised host can steal the key), but it has interesting
+niche uses:
+
+- **Encrypted seed backup:** an NTAG215 storing an encrypted seed is a
+  convenient portable backup — tap your phone to read it, type the passphrase
+  to decrypt. More convenient than a metal plate, less secure than a hardware
+  signer.
+- **Shamir shard carrier:** each tag holds one SSS share. You need M of N tags
+  to reconstruct the seed. Distribute the tags to different locations/people.
+  A single stolen tag is useless. This is a **key-recovery** tool, not a signer.
+- **Identity token:** an NDEF URI tag with your npub. Tap to share your Nostr
+  identity with a phone. Not a signer — just a business card for Nostr.
+- **PIN-protected key release:** a DESFire or JCOP tag that only releases the
+  seed after the host verifies a PIN. The host never sees the key until the PIN
+  is correct. Better than a raw tag, but the host still gets the key after the
+  PIN — so a compromised host can still steal it.
+
+### The fundamental limitation
+
+A passive tag that stores keys **cannot protect the key from a compromised
+host**. Once the host reads the key, the host has it. This is the same problem
+as storing a private key in a file — the OS can steal it. The only way to
+protect the key from the host is to **never release the raw key** — which means
+the tag must do the signing itself (Concept A or B), or the tag must participate
+in a protocol where the host sends a hash to sign and the tag returns a
+signature (which requires an MCU + crypto = not a passive tag).
+
+**The one exception:** a **secure element** (JCOP / Infineon) can do
+"sign inside, never release the key." The host sends the message hash; the
+secure element signs it internally and returns the signature. The private key
+never leaves the chip. This is how smart card signing works (e.g. FIDO2 keys,
+PIV cards). But this is Concept A (active signer), not a passive tag.
+
+---
+
+## Open questions (all concepts)
+
+- **Is the goal a signer (does crypto on-device) or a key carrier (stores keys for a host to use)?**
+  - Signer → Concept A (card with display) or B (ring). The key never leaves the device.
+  - Key carrier → Concept C (passive tag). The host gets the key. Simpler but less secure.
+- **Form factor:** card (credit card size, room for display) vs ring (tiny, no display)?
+- **Power:** passive (secure element, no battery) vs semi-passive (nRF52840 + thin battery)?
+- **Approval model:** on-device display (secure, needs a screen) vs reader display (trusts the reader, no screen needed) vs two-tap (medium security, no screen)?
+- **Host reader:** USB NFC reader (ACR122U, ~$15) vs phone NFC (universal, no dongle)?
+- **MCU/toolchain:** nRF52840 + C (DIY-friendly) vs JCOP + Java Card (production, NDA)?
+- **Could a passive tag + a host-side n_signer be a useful "portable encrypted seed backup" even if it's not a signer?** (Yes — for key recovery / Shamir shard distribution.)
+
+---
+
+## Comparison across all three concepts (NFC, BLE, IR)
+
+| | NFC card (A) | NFC ring (B) | NFC tag (C) | BLE wearable | IR air-gap |
+|---|---|---|---|---|---|
+| Does signing on-device? | **Yes** | **Yes** | No (host signs) | Yes | Yes |
+| Key leaves device? | **No** | **No** | Yes (host reads it) | No | No |
+| Power | Reader + thin battery | Reader (passive) or battery | **Reader (passive)** | Battery | Battery |
+| Display | Tiny e-paper | None | None | Tiny OLED | Tiny OLED/e-paper |
+| Approval | On-card display + button | Reader display (two-tap) | N/A (host decides) | On-device display + buttons | On-device display + buttons |
+| Attack radius | ~4 cm | ~4 cm | ~4 cm | ~10 m | ~1 m (line-of-sight) |
+| Host needs | NFC reader or phone NFC | NFC reader or phone NFC | NFC reader or phone NFC | BT (universal) | USB IR dongle |
+| Form factor | Card | Ring | Tag/card/sticker | Wristband/pendant | Handheld |
+| Build difficulty | Hard (flex PCB) | Very hard (custom ring) | **Easy (off-the-shelf tag)** | Moderate | Moderate |
+| Best for | Daily signing | Quick tap-to-sign | Key backup / recovery | Wearable daily use | High-security air-gap |
+
+---
+
+## Next steps
+
+- Decide: signer (A/B) vs key carrier (C) vs both
+- Decide: card vs ring vs tag
+- Decide: DIY prototype (nRF52840 + ACR122U) vs production (secure element)
+- Explore the Shamir-shard-on-NFC-tags idea as a key-recovery tool
+- Explore the encrypted-seed-on-NTAG215 idea as a portable backup
+- Write a plan for the chosen direction

firmware/teensy41/README.md

@@ -0,0 +1,60 @@
+# n_signer Teensy 4.1 Firmware
+
+**Status:** Planned — not yet implemented. See
+[`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md).
+
+The **Teensy 4.1** (NXP i.MX RT1062, Cortex-M7 @ 600 MHz) is the high-capacity
+OTP pad target. Its built-in SD slot supports **1 TB SDXC cards (exFAT)** via
+PJRC's SdFat library, making it the ideal hardware signer for large one-time-pad
+storage.
+
+## Why the Teensy 4.1
+
+| Concern | Teensy 4.1 | CYD (ESP32) | Feather S3 TFT (ESP32-S3) |
+|---|---|---|---|
+| MCU | 600 MHz Cortex-M7 | 240 MHz Xtensa LX6 | 240 MHz Xtensa LX7 |
+| SRAM | 1 MB + 16 MB PSRAM | 512 KB (no PSRAM) | 512 KB + quad PSRAM |
+| SD slot | **4-bit SDMMC, exFAT, up to 2 TB** | 1-bit SDSPI, FAT32, up to 32 GB | — |
+| USB | Hi-Speed (480 Mbps) device + host | CH340 UART only | Full-Speed USB |
+| WiFi | **None** | Yes (unused) | Yes (unused) |
+| Ethernet | 10/100 PHY (optional) | — | — |
+| PQ crypto speed | ~1-2 s SLH-DSA-128s | 5-30 s SLH-DSA-128s | 5-30 s SLH-DSA-128s |
+
+## SD card size support
+
+| Card type | Size | Works? |
+|---|---|---|
+| SDSC | ≤ 2 GB | Yes (FAT16/32) |
+| SDHC | 2 – 32 GB | Yes (FAT32) |
+| **SDXC** | **32 GB – 2 TB** | **Yes (exFAT via SdFat)** |
+| SDUC | 2 – 128 TB | No |
+
+**1 TB SDXC cards work** — SdFat has native exFAT support, and the Teensy's
+4-bit SDMMC bus runs at ~20-40 MB/s. No reformatting needed.
+
+## Display + touch
+
+**4.0" ST7796S 480×320 SPI TFT with XPT2046 resistive touch** (Hosyond or
+equivalent, ~$12-15). Specs: 4-wire SPI, RGB 65K, 3.3V~5V (works at the Teensy's
+3.3V logic), XPT2046 resistive touch, includes touch pen + on-module SD slot.
+
+Resistive touch is the right choice for a hardware signer (deliberate physical
+activation, stylus-compatible, simple driver). The XPT2046 driver ports from
+the CYD's [`touch.c`](../cyd_esp32_2432s028/main/touch.c) with 480×320
+resolution constants. The ST7796S display driver is new code (different init
+sequence than the CYD's ILI9341).
+
+Wiring: TFT SPI on pins 11/12/13, CS=10, DC=9, RESET=8, BL=22; touch shares
+the SPI bus with T_CS=7, T_IRQ=6. See
+[`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md) for the
+full pin table.
+
+## Build (planned)
+
+```bash
+# Arduino CLI / Teensyduino
+arduino-cli compile --fqbn teensy:avr:teensy41 firmware/teensy41
+arduino-cli upload -p /dev/ttyACM0 --fqbn teensy:avr:teensy41 firmware/teensy41
+```
+
+See the port plan: [`plans/teensy41_signer_port.md`](../../plans/teensy41_signer_port.md).

install_qube_fips_nsigner.sh

@@ -185,7 +185,7 @@ write_signer_start_script() {
 set -euo pipefail
 
 export PATH="$HOME/.local/bin:$PATH"
-LISTEN_TARGET="${NSIGNER_LISTEN_TARGET:-tcp:[::]:8080}"
+LISTEN_TARGET="${NSIGNER_LISTEN_TARGET:-tcp:[::]:11111}"
 
 # If first arg is "qrexec", start in unix bridge mode for Qubes qrexec.
 # Otherwise, pass any extra args through to nsigner (e.g. --allow-all).

libotppad/Makefile

@@ -0,0 +1,25 @@
+CC ?= gcc
+CFLAGS ?= -Wall -Wextra -std=c99 -O2
+AR ?= ar
+
+OBJS = libotppad.o
+LIB  = libotppad.a
+
+all: $(LIB)
+
+$(LIB): $(OBJS)
+	$(AR) rcs $@ $(OBJS)
+
+libotppad.o: libotppad.c libotppad.h
+	$(CC) $(CFLAGS) -c libotppad.c -o libotppad.o
+
+test: test_libotppad
+	./test_libotppad
+
+test_libotppad: test_libotppad.c $(LIB)
+	$(CC) $(CFLAGS) -I. test_libotppad.c -L. -lotppad -o test_libotppad
+
+clean:
+	rm -f $(OBJS) $(LIB) test_libotppad
+
+.PHONY: all test clean

libotppad/libotppad.c

@@ -0,0 +1,398 @@
+/*
+ * libotppad.c — implementation of libotppad.h.
+ *
+ * Extracted from the otp project (src/crypto.c, src/padding.c, src/pads.c)
+ * and made self-contained: no main.h, no global state, no UI.
+ */
+#define _POSIX_C_SOURCE 200809L
+
+#include "libotppad.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+/* ------------------------------------------------------------------ */
+/* XOR transform                                                      */
+/* ------------------------------------------------------------------ */
+
+int otppad_xor(const unsigned char *data, size_t data_len,
+               const unsigned char *pad_data, unsigned char *result) {
+    if (!data || !pad_data || !result) {
+        return 1;
+    }
+    for (size_t i = 0; i < data_len; i++) {
+        result[i] = data[i] ^ pad_data[i];
+    }
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Base64                                                             */
+/* ------------------------------------------------------------------ */
+
+static const char b64_chars[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static const int b64_decode_table[256] = {
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63,
+    52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,
+    -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,
+    15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,
+    -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,
+    41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+    -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+};
+
+char *otppad_base64_encode(const unsigned char *input, int length) {
+    if (!input || length < 0) return NULL;
+    int output_length = 4 * ((length + 2) / 3);
+    char *encoded = (char *)malloc((size_t)output_length + 1);
+    if (!encoded) return NULL;
+
+    int i, j;
+    for (i = 0, j = 0; i < length;) {
+        uint32_t octet_a = i < length ? input[i++] : 0;
+        uint32_t octet_b = i < length ? input[i++] : 0;
+        uint32_t octet_c = i < length ? input[i++] : 0;
+        uint32_t triple = (octet_a << 16) + (octet_b << 8) + octet_c;
+        encoded[j++] = b64_chars[(triple >> 18) & 63];
+        encoded[j++] = b64_chars[(triple >> 12) & 63];
+        encoded[j++] = b64_chars[(triple >> 6) & 63];
+        encoded[j++] = b64_chars[triple & 63];
+    }
+    for (int pad = 0; pad < (3 - length % 3) % 3; pad++) {
+        encoded[output_length - 1 - pad] = '=';
+    }
+    encoded[output_length] = '\0';
+    return encoded;
+}
+
+unsigned char *otppad_base64_decode(const char *input, int *output_length) {
+    if (!input || !output_length) return NULL;
+    int input_length = (int)strlen(input);
+    if (input_length % 4 != 0) return NULL;
+
+    *output_length = input_length / 4 * 3;
+    if (input[input_length - 1] == '=') (*output_length)--;
+    if (input[input_length - 2] == '=') (*output_length)--;
+
+    unsigned char *decoded = (unsigned char *)malloc((size_t)*output_length);
+    if (!decoded) return NULL;
+
+    int i, j;
+    for (i = 0, j = 0; i < input_length;) {
+        int sa = input[i] == '=' ? 0 & i++ : b64_decode_table[(unsigned char)input[i++]];
+        int sb = input[i] == '=' ? 0 & i++ : b64_decode_table[(unsigned char)input[i++]];
+        int sc = input[i] == '=' ? 0 & i++ : b64_decode_table[(unsigned char)input[i++]];
+        int sd = input[i] == '=' ? 0 & i++ : b64_decode_table[(unsigned char)input[i++]];
+        if (sa == -1 || sb == -1 || sc == -1 || sd == -1) {
+            free(decoded);
+            return NULL;
+        }
+        uint32_t triple = ((uint32_t)sa << 18) + ((uint32_t)sb << 12) +
+                          ((uint32_t)sc << 6) + (uint32_t)sd;
+        if (j < *output_length) decoded[j++] = (triple >> 16) & 255;
+        if (j < *output_length) decoded[j++] = (triple >> 8) & 255;
+        if (j < *output_length) decoded[j++] = triple & 255;
+    }
+    return decoded;
+}
+
+/* ------------------------------------------------------------------ */
+/* Padmé padding                                                      */
+/* ------------------------------------------------------------------ */
+
+size_t otppad_chunk_size(size_t msg_len) {
+    size_t chunk = 256;
+    while (chunk < msg_len + 1) {
+        chunk *= 2;
+    }
+    return chunk;
+}
+
+int otppad_pad_apply(unsigned char *buffer, size_t msg_len, size_t chunk_size) {
+    if (!buffer) return 1;
+    if (chunk_size < msg_len + 1) return 2;
+    buffer[msg_len] = 0x80;
+    if (chunk_size > msg_len + 1) {
+        memset(buffer + msg_len + 1, 0x00, chunk_size - msg_len - 1);
+    }
+    return 0;
+}
+
+int otppad_pad_remove(const unsigned char *buffer, size_t chunk_size,
+                      size_t *msg_len) {
+    if (!buffer || !msg_len) return 1;
+    if (chunk_size == 0) return 2;
+    for (int i = (int)chunk_size - 1; i >= 0; i--) {
+        if (buffer[i] == 0x80) {
+            *msg_len = (size_t)i;
+            return 0;
+        } else if (buffer[i] != 0x00) {
+            return 3;
+        }
+    }
+    return 4;
+}
+
+void otppad_chunk_format(size_t chunk_size, char *buffer, size_t buffer_size) {
+    if (!buffer || buffer_size == 0) return;
+    if (chunk_size < 1024) {
+        snprintf(buffer, buffer_size, "%zu bytes", chunk_size);
+    } else if (chunk_size < 1024 * 1024) {
+        snprintf(buffer, buffer_size, "%.1f KB", chunk_size / 1024.0);
+    } else if (chunk_size < 1024 * 1024 * 1024) {
+        snprintf(buffer, buffer_size, "%.1f MB", chunk_size / (1024.0 * 1024.0));
+    } else {
+        snprintf(buffer, buffer_size, "%.1f GB",
+                 chunk_size / (1024.0 * 1024.0 * 1024.0));
+    }
+}
+
+/* ------------------------------------------------------------------ */
+/* ASCII armored message format                                       */
+/* ------------------------------------------------------------------ */
+
+int otppad_armor_parse(const char *message, char *chksum, uint64_t *offset,
+                       char *base64_data, size_t base64_buf_size) {
+    if (!message || !chksum || !offset || !base64_data || base64_buf_size == 0) {
+        return 1;
+    }
+
+    size_t msg_len = strlen(message);
+    char *copy = (char *)malloc(msg_len + 1);
+    if (!copy) return 1;
+    strcpy(copy, message);
+
+    char *line = strtok(copy, "\n");
+    int found_begin = 0, in_data = 0, found_chksum = 0, found_offset = 0;
+    chksum[0] = '\0';
+    *offset = 0;
+    base64_data[0] = '\0';
+
+    while (line != NULL) {
+        if (strcmp(line, OTPPAD_ARMOR_BEGIN) == 0) {
+            found_begin = 1;
+        } else if (strcmp(line, OTPPAD_ARMOR_END) == 0) {
+            break;
+        } else if (found_begin) {
+            if (strncmp(line, "Pad-ChkSum: ", 12) == 0) {
+                strncpy(chksum, line + 12, OTPPAD_CHKSUM_HEX_LEN);
+                chksum[OTPPAD_CHKSUM_HEX_LEN] = '\0';
+                found_chksum = 1;
+            } else if (strncmp(line, "Pad-Offset: ", 12) == 0) {
+                *offset = strtoull(line + 12, NULL, 10);
+                found_offset = 1;
+            } else if (strlen(line) == 0) {
+                in_data = 1;
+            } else if (in_data) {
+                strncat(base64_data, line, base64_buf_size - strlen(base64_data) - 1);
+            } else if (strncmp(line, "Version:", 8) != 0 &&
+                       strncmp(line, "Pad-", 4) != 0) {
+                strncat(base64_data, line, base64_buf_size - strlen(base64_data) - 1);
+            }
+        }
+        line = strtok(NULL, "\n");
+    }
+
+    free(copy);
+    if (!found_begin || !found_chksum || !found_offset) {
+        return 2;
+    }
+    return 0;
+}
+
+int otppad_armor_generate(const char *version, const char *chksum,
+                          uint64_t offset,
+                          const unsigned char *encrypted_data, size_t data_length,
+                          char **ascii_output) {
+    if (!chksum || !encrypted_data || !ascii_output) return 1;
+
+    char *b64 = otppad_base64_encode(encrypted_data, (int)data_length);
+    if (!b64) return 2;
+
+    size_t b64_len = strlen(b64);
+    size_t total = 256 + b64_len + (b64_len / 64) + 64;
+    *ascii_output = (char *)malloc(total);
+    if (!*ascii_output) {
+        free(b64);
+        return 3;
+    }
+
+    char line[256];
+    strcpy(*ascii_output, OTPPAD_ARMOR_BEGIN);
+    strcat(*ascii_output, "\n");
+
+    snprintf(line, sizeof(line), "Version: %s\n", version ? version : "v0");
+    strcat(*ascii_output, line);
+
+    snprintf(line, sizeof(line), "Pad-ChkSum: %s\n", chksum);
+    strcat(*ascii_output, line);
+
+    snprintf(line, sizeof(line), "Pad-Offset: %llu\n",
+             (unsigned long long)offset);
+    strcat(*ascii_output, line);
+
+    strcat(*ascii_output, "\n");
+
+    int b64_len_int = (int)b64_len;
+    for (int i = 0; i < b64_len_int; i += 64) {
+        snprintf(line, sizeof(line), "%.64s\n", b64 + i);
+        strcat(*ascii_output, line);
+    }
+
+    strcat(*ascii_output, OTPPAD_ARMOR_END);
+    strcat(*ascii_output, "\n");
+
+    free(b64);
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Binary .otp file format                                            */
+/* ------------------------------------------------------------------ */
+
+int otppad_bin_header_write(FILE *fp, const otppad_bin_header_t *hdr) {
+    if (!fp || !hdr) return 1;
+    if (fwrite(OTPPAD_MAGIC, 1, OTPPAD_MAGIC_LEN, fp) != OTPPAD_MAGIC_LEN) return 2;
+    if (fwrite(&hdr->version, sizeof(uint16_t), 1, fp) != 1) return 3;
+    if (fwrite(hdr->pad_chksum, 1, OTPPAD_CHKSUM_BIN_LEN, fp) != OTPPAD_CHKSUM_BIN_LEN) return 4;
+    if (fwrite(&hdr->pad_offset, sizeof(uint64_t), 1, fp) != 1) return 5;
+    if (fwrite(&hdr->file_mode, sizeof(uint32_t), 1, fp) != 1) return 6;
+    if (fwrite(&hdr->file_size, sizeof(uint64_t), 1, fp) != 1) return 7;
+    return 0;
+}
+
+int otppad_bin_header_read(FILE *fp, otppad_bin_header_t *hdr) {
+    if (!fp || !hdr) return 1;
+    memset(hdr, 0, sizeof(*hdr));
+    if (fread(hdr->magic, 1, OTPPAD_MAGIC_LEN, fp) != OTPPAD_MAGIC_LEN) return 2;
+    if (fread(&hdr->version, sizeof(uint16_t), 1, fp) != 1) return 3;
+    if (fread(hdr->pad_chksum, 1, OTPPAD_CHKSUM_BIN_LEN, fp) != OTPPAD_CHKSUM_BIN_LEN) return 4;
+    if (fread(&hdr->pad_offset, sizeof(uint64_t), 1, fp) != 1) return 5;
+    if (fread(&hdr->file_mode, sizeof(uint32_t), 1, fp) != 1) return 6;
+    if (fread(&hdr->file_size, sizeof(uint64_t), 1, fp) != 1) return 7;
+    return 0;
+}
+
+int otppad_bin_is_magic(const unsigned char *buf, size_t len) {
+    if (!buf || len < OTPPAD_MAGIC_LEN) return 0;
+    return memcmp(buf, OTPPAD_MAGIC, OTPPAD_MAGIC_LEN) == 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Per-pad .state file                                                */
+/* ------------------------------------------------------------------ */
+
+int otppad_state_read(const char *pads_dir, const char *chksum, uint64_t *offset) {
+    if (!pads_dir || !chksum || !offset) return 1;
+    char path[1024];
+    snprintf(path, sizeof(path), "%s/%s.state", pads_dir, chksum);
+
+    FILE *f = fopen(path, "r");
+    if (!f) return 2;
+
+    char line[128];
+    if (!fgets(line, sizeof(line), f)) {
+        fclose(f);
+        return 3;
+    }
+    fclose(f);
+
+    if (strncmp(line, "offset=", 7) != 0) {
+        return 4;
+    }
+    *offset = strtoull(line + 7, NULL, 10);
+    return 0;
+}
+
+int otppad_state_write(const char *pads_dir, const char *chksum, uint64_t offset) {
+    if (!pads_dir || !chksum) return 1;
+    char path[1024];
+    char tmp[1100];
+    snprintf(path, sizeof(path), "%s/%s.state", pads_dir, chksum);
+    snprintf(tmp, sizeof(tmp), "%s/%s.state.tmp.XXXXXX", pads_dir, chksum);
+
+    int tfd = mkstemp(tmp);
+    if (tfd < 0) return 2;
+    FILE *f = fdopen(tfd, "w");
+    if (!f) {
+        close(tfd);
+        unlink(tmp);
+        return 3;
+    }
+    if (fprintf(f, "offset=%llu\n", (unsigned long long)offset) < 0) {
+        fclose(f);
+        unlink(tmp);
+        return 4;
+    }
+    if (fclose(f) != 0) {
+        unlink(tmp);
+        return 5;
+    }
+    if (rename(tmp, path) != 0) {
+        unlink(tmp);
+        return 6;
+    }
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Pad checksum                                                       */
+/* ------------------------------------------------------------------ */
+
+int otppad_checksum(const char *pad_path, char *checksum_hex) {
+    if (!pad_path || !checksum_hex) return 1;
+
+    FILE *file = fopen(pad_path, "rb");
+    if (!file) return 2;
+
+    unsigned char checksum[OTPPAD_CHKSUM_BIN_LEN];
+    unsigned char buffer[64 * 1024];
+    size_t bytes_read;
+    size_t total_bytes = 0;
+    memset(checksum, 0, OTPPAD_CHKSUM_BIN_LEN);
+
+    while ((bytes_read = fread(buffer, 1, sizeof(buffer), file)) > 0) {
+        for (size_t i = 0; i < bytes_read; i++) {
+            size_t pos = total_bytes + i;
+            unsigned char bucket = (unsigned char)(pos % OTPPAD_CHKSUM_BIN_LEN);
+            checksum[bucket] ^= (unsigned char)buffer[i] ^
+                                (unsigned char)((pos >> 8) & 0xFF) ^
+                                (unsigned char)((pos >> 16) & 0xFF) ^
+                                (unsigned char)((pos >> 24) & 0xFF);
+        }
+        total_bytes += bytes_read;
+    }
+    fclose(file);
+
+    file = fopen(pad_path, "rb");
+    if (!file) return 3;
+    unsigned char pad_key[OTPPAD_CHKSUM_BIN_LEN];
+    if (fread(pad_key, 1, OTPPAD_CHKSUM_BIN_LEN, file) != OTPPAD_CHKSUM_BIN_LEN) {
+        fclose(file);
+        return 4;
+    }
+    fclose(file);
+
+    unsigned char enc[OTPPAD_CHKSUM_BIN_LEN];
+    for (int i = 0; i < OTPPAD_CHKSUM_BIN_LEN; i++) {
+        enc[i] = checksum[i] ^ pad_key[i];
+    }
+    for (int i = 0; i < OTPPAD_CHKSUM_BIN_LEN; i++) {
+        sprintf(checksum_hex + (i * 2), "%02x", enc[i]);
+    }
+    checksum_hex[OTPPAD_CHKSUM_HEX_LEN] = '\0';
+    return 0;
+}

libotppad/libotppad.h

@@ -0,0 +1,201 @@
+/*
+ * libotppad.h — format-critical helpers for one-time-pad encryption.
+ *
+ * Bit-compatible with the `otp` project (https://git.laantungir.net/laantungir/otp):
+ *   - XOR transform
+ *   - ASCII armored message format ("-----BEGIN OTP MESSAGE-----")
+ *   - Binary .otp file format (magic "OTP\0")
+ *   - ISO/IEC 9797-1 Method 2 (Padmé) padding with exponential bucketing
+ *   - Per-pad .state file ("offset=<n>\n")
+ *   - 256-bit XOR pad checksum (position-dependent, XORed with first 32 pad bytes)
+ *
+ * This library is self-contained: it does not depend on the `otp` project's
+ * main.h, global state, or UI code. Both `otp` and `n_signer` link against it.
+ *
+ * License: same as the otp project.
+ */
+#ifndef LIBOTPPAD_H
+#define LIBOTPPAD_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* ------------------------------------------------------------------ */
+/* Constants                                                          */
+/* ------------------------------------------------------------------ */
+
+#define OTPPAD_CHKSUM_HEX_LEN   64          /* 32 bytes -> 64 hex chars */
+#define OTPPAD_CHKSUM_BIN_LEN   32
+#define OTPPAD_HEADER_RESERVED  32          /* bytes reserved at start of pad */
+#define OTPPAD_MAGIC            "OTP\0"     /* 4-byte binary file magic   */
+#define OTPPAD_MAGIC_LEN        4
+#define OTPPAD_FORMAT_VERSION   1           /* binary .otp format version */
+
+#define OTPPAD_ARMOR_BEGIN      "-----BEGIN OTP MESSAGE-----"
+#define OTPPAD_ARMOR_END        "-----END OTP MESSAGE-----"
+
+/* ------------------------------------------------------------------ */
+/* XOR transform                                                      */
+/* ------------------------------------------------------------------ */
+
+/*
+ * XOR `data_len` bytes of `data` with `pad_data` into `result`.
+ * `data`, `pad_data`, `result` must each be at least `data_len` bytes.
+ * `result` may alias `data` or `pad_data`.
+ * Returns 0 on success, non-zero on null pointer.
+ */
+int otppad_xor(const unsigned char *data, size_t data_len,
+               const unsigned char *pad_data, unsigned char *result);
+
+/* ------------------------------------------------------------------ */
+/* Base64                                                             */
+/* ------------------------------------------------------------------ */
+
+/* Encode `length` bytes of `input` as a NUL-terminated base64 string.
+ * Caller frees the returned string. Returns NULL on allocation failure. */
+char *otppad_base64_encode(const unsigned char *input, int length);
+
+/* Decode NUL-terminated base64 `input` into bytes.
+ * Caller frees the returned buffer. *output_length receives the byte count.
+ * Returns NULL on invalid input or allocation failure. */
+unsigned char *otppad_base64_decode(const char *input, int *output_length);
+
+/* ------------------------------------------------------------------ */
+/* Padmé padding (ISO/IEC 9797-1 Method 2) + exponential bucketing    */
+/* ------------------------------------------------------------------ */
+
+/* Calculate the bucket size for a message of `msg_len` bytes.
+ * Starts at 256 bytes and doubles until `chunk >= msg_len + 1`. */
+size_t otppad_chunk_size(size_t msg_len);
+
+/* Apply Padmé padding to `buffer` (must hold `chunk_size` bytes).
+ * Writes 0x80 at `buffer[msg_len]` then zeroes to `chunk_size`.
+ * Returns 0 on success, non-zero on error. */
+int otppad_pad_apply(unsigned char *buffer, size_t msg_len, size_t chunk_size);
+
+/* Remove Padmé padding: scan backwards for 0x80, set *msg_len to its index.
+ * Returns 0 on success, non-zero on invalid padding. */
+int otppad_pad_remove(const unsigned char *buffer, size_t chunk_size,
+                      size_t *msg_len);
+
+/* Human-readable chunk size string (e.g. "256 bytes", "1.0 KB"). */
+void otppad_chunk_format(size_t chunk_size, char *buffer, size_t buffer_size);
+
+/* ------------------------------------------------------------------ */
+/* ASCII armored message format                                       */
+/* ------------------------------------------------------------------ */
+
+/*
+ * Parse an ASCII-armored OTP message.
+ *
+ * `chksum` must be at least OTPPAD_CHKSUM_HEX_LEN+1 bytes.
+ * `base64_data` must be at least `base64_buf_size` bytes; the decoded
+ * ciphertext is NOT returned here — only the raw base64 text. Use
+ * otppad_base64_decode() to get the bytes.
+ *
+ * On success returns 0 and sets `chksum`, `*offset`, and `base64_data`.
+ * Returns non-zero on malformed input.
+ */
+int otppad_armor_parse(const char *message, char *chksum, uint64_t *offset,
+                       char *base64_data, size_t base64_buf_size);
+
+/*
+ * Build an ASCII-armored OTP message.
+ *
+ * `version` is the version string for the "Version:" header (e.g. "v0.3.53").
+ * `chksum` is the 64-char hex pad checksum.
+ * `offset` is the pad offset where the slice begins.
+ * `encrypted_data` / `data_length` is the ciphertext to base64-encode.
+ *
+ * On success returns 0 and sets `*ascii_output` to a malloc'd NUL-terminated
+ * string. Caller frees `*ascii_output`.
+ */
+int otppad_armor_generate(const char *version, const char *chksum,
+                          uint64_t offset,
+                          const unsigned char *encrypted_data, size_t data_length,
+                          char **ascii_output);
+
+/* ------------------------------------------------------------------ */
+/* Binary .otp file format                                            */
+/* ------------------------------------------------------------------ */
+
+/*
+ * Binary .otp header (58 bytes). All fields are little-endian on disk
+ * (written via fwrite of host-endian integers — matches the otp project,
+ * which is x86/ARM little-endian in practice).
+ *
+ * Offset  Size  Field
+ * 0       4     Magic "OTP\0"
+ * 4       2     Version (uint16, currently 1)
+ * 6       32    Pad checksum (binary, 32 bytes)
+ * 38      8     Pad offset (uint64)
+ * 46      4     Original file mode (uint32)
+ * 50      8     Original file size (uint64, NOT padded size)
+ * 58      var   Encrypted (padded) data
+ */
+typedef struct {
+    char          magic[OTPPAD_MAGIC_LEN];
+    uint16_t      version;
+    unsigned char pad_chksum[OTPPAD_CHKSUM_BIN_LEN];
+    uint64_t      pad_offset;
+    uint32_t      file_mode;
+    uint64_t      file_size;        /* original (unpadded) size */
+} otppad_bin_header_t;
+
+/* Write a binary .otp header to `fp`. Returns 0 on success. */
+int otppad_bin_header_write(FILE *fp, const otppad_bin_header_t *hdr);
+
+/* Read a binary .otp header from `fp`. Returns 0 on success, non-zero on
+ * malformed input. Does not validate the magic — use otppad_bin_is_magic()
+ * first if needed. */
+int otppad_bin_header_read(FILE *fp, otppad_bin_header_t *hdr);
+
+/* Return 1 if the first 4 bytes of `buf` match the OTP magic. */
+int otppad_bin_is_magic(const unsigned char *buf, size_t len);
+
+/* ------------------------------------------------------------------ */
+/* Per-pad .state file                                                */
+/* ------------------------------------------------------------------ */
+
+/*
+ * Read the offset from `<pads_dir>/<chksum>.state`.
+ * Returns 0 on success and sets *offset. Non-zero on error.
+ */
+int otppad_state_read(const char *pads_dir, const char *chksum, uint64_t *offset);
+
+/*
+ * Atomically write the offset to `<pads_dir>/<chksum>.state`.
+ * Writes to a temp file then renames, so a crash cannot corrupt the state.
+ * Returns 0 on success, non-zero on error.
+ */
+int otppad_state_write(const char *pads_dir, const char *chksum, uint64_t offset);
+
+/* ------------------------------------------------------------------ */
+/* Pad checksum                                                       */
+/* ------------------------------------------------------------------ */
+
+/*
+ * Compute the 256-bit XOR checksum of the pad file at `pad_path`.
+ * `checksum_hex` must be at least OTPPAD_CHKSUM_HEX_LEN+1 bytes.
+ *
+ * Algorithm (matches otp/src/crypto.c:calculate_checksum):
+ *   - XOR every byte into one of 32 buckets, selected by (position % 32),
+ *     also XORing in bytes (pos>>8),(pos>>16),(pos>>24) of the position.
+ *   - XOR the resulting 32-byte checksum with the first 32 bytes of the pad
+ *     (the "pad key").
+ *   - Hex-encode the 32-byte result.
+ *
+ * Returns 0 on success, non-zero on error.
+ */
+int otppad_checksum(const char *pad_path, char *checksum_hex);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LIBOTPPAD_H */

libotppad/test_libotppad.c

@@ -0,0 +1,213 @@
+/*
+ * test_libotppad.c — unit tests for libotppad.
+ *
+ * Covers: XOR, base64 round-trip, Padmé padding round-trip, ASCII armor
+ * round-trip, binary header round-trip, .state file round-trip, and pad
+ * checksum against a known pad.
+ */
+#define _POSIX_C_SOURCE 200809L
+
+#include "libotppad.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+static int failures = 0;
+
+#define CHECK(cond, msg) do { \
+    if (!(cond)) { \
+        fprintf(stderr, "FAIL: %s (%s:%d)\n", (msg), __FILE__, __LINE__); \
+        failures++; \
+    } else { \
+        printf("ok: %s\n", (msg)); \
+    } \
+} while (0)
+
+static void test_xor(void) {
+    unsigned char data[] = {0x01, 0x02, 0x03, 0x04, 0x05};
+    unsigned char pad[]  = {0xff, 0xee, 0xdd, 0xcc, 0xbb};
+    unsigned char out[5];
+    CHECK(otppad_xor(data, 5, pad, out) == 0, "xor returns 0");
+    CHECK(out[0] == 0xfe && out[1] == 0xec && out[2] == 0xde &&
+          out[3] == 0xc8 && out[4] == 0xbe, "xor values correct");
+    /* in-place aliasing */
+    CHECK(otppad_xor(data, 5, pad, data) == 0, "xor in-place");
+    CHECK(data[0] == 0xfe, "xor in-place value");
+}
+
+static void test_base64(void) {
+    const char *in = "Hello, World!";
+    int len = (int)strlen(in);
+    char *enc = otppad_base64_encode((const unsigned char *)in, len);
+    CHECK(enc != NULL, "base64 encode");
+    int dlen = 0;
+    unsigned char *dec = otppad_base64_decode(enc, &dlen);
+    CHECK(dec != NULL, "base64 decode");
+    CHECK(dlen == len, "base64 length preserved");
+    CHECK(memcmp(dec, in, len) == 0, "base64 round-trip");
+    free(enc);
+    free(dec);
+
+    /* empty input */
+    enc = otppad_base64_encode((const unsigned char *)"", 0);
+    CHECK(enc != NULL && strcmp(enc, "") == 0, "base64 empty");
+    free(enc);
+}
+
+static void test_padding(void) {
+    /* 10-byte message -> 256-byte bucket */
+    size_t chunk = otppad_chunk_size(10);
+    CHECK(chunk == 256, "chunk size for 10 bytes is 256");
+    /* 300-byte message -> 512-byte bucket */
+    chunk = otppad_chunk_size(300);
+    CHECK(chunk == 512, "chunk size for 300 bytes is 512");
+    /* 256-byte message -> 512 (needs +1 for 0x80) */
+    chunk = otppad_chunk_size(256);
+    CHECK(chunk == 512, "chunk size for 256 bytes is 512 (needs +1)");
+
+    unsigned char buf[512];
+    const char *msg = "test message";
+    size_t msg_len = strlen(msg);
+    memset(buf, 0xaa, sizeof(buf));
+    memcpy(buf, msg, msg_len);
+    chunk = otppad_chunk_size(msg_len);
+    CHECK(otppad_pad_apply(buf, msg_len, chunk) == 0, "pad apply");
+    CHECK(buf[msg_len] == 0x80, "pad marker at msg_len");
+    size_t recovered;
+    CHECK(otppad_pad_remove(buf, chunk, &recovered) == 0, "pad remove");
+    CHECK(recovered == msg_len, "pad remove recovers length");
+    CHECK(memcmp(buf, msg, msg_len) == 0, "pad round-trip preserves message");
+}
+
+static void test_armor(void) {
+    const char *chksum =
+        "333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e";
+    unsigned char ct[] = {0xde, 0xad, 0xbe, 0xef, 0x10, 0x20, 0x30, 0x40};
+    uint64_t offset = 12345;
+    char *armor = NULL;
+    CHECK(otppad_armor_generate("v0.3.53", chksum, offset, ct, sizeof(ct),
+                                &armor) == 0,
+          "armor generate");
+    CHECK(armor != NULL && strstr(armor, "BEGIN OTP MESSAGE") != NULL,
+          "armor has begin marker");
+
+    char parsed_chk[OTPPAD_CHKSUM_HEX_LEN + 1];
+    uint64_t parsed_off;
+    char parsed_b64[8192];
+    CHECK(otppad_armor_parse(armor, parsed_chk, &parsed_off, parsed_b64,
+                             sizeof(parsed_b64)) == 0,
+          "armor parse");
+    CHECK(strcmp(parsed_chk, chksum) == 0, "armor chksum round-trip");
+    CHECK(parsed_off == offset, "armor offset round-trip");
+
+    int dlen = 0;
+    unsigned char *dec = otppad_base64_decode(parsed_b64, &dlen);
+    CHECK(dec != NULL && dlen == (int)sizeof(ct), "armor b64 length");
+    CHECK(dec && memcmp(dec, ct, sizeof(ct)) == 0, "armor ciphertext round-trip");
+    free(armor);
+    free(dec);
+}
+
+static void test_bin_header(void) {
+    otppad_bin_header_t hdr;
+    memset(&hdr, 0, sizeof(hdr));
+    memcpy(hdr.magic, OTPPAD_MAGIC, OTPPAD_MAGIC_LEN);
+    hdr.version = OTPPAD_FORMAT_VERSION;
+    memset(hdr.pad_chksum, 0xab, OTPPAD_CHKSUM_BIN_LEN);
+    hdr.pad_offset = 999;
+    hdr.file_mode = 0644;
+    hdr.file_size = 4096;
+
+    const char *path = "test_bin_header.tmp";
+    FILE *fp = fopen(path, "wb");
+    CHECK(fp != NULL, "open bin header tmp for write");
+    CHECK(otppad_bin_header_write(fp, &hdr) == 0, "bin header write");
+    fclose(fp);
+
+    fp = fopen(path, "rb");
+    CHECK(fp != NULL, "open bin header tmp for read");
+    otppad_bin_header_t hdr2;
+    CHECK(otppad_bin_header_read(fp, &hdr2) == 0, "bin header read");
+    fclose(fp);
+    unlink(path);
+
+    CHECK(hdr2.version == hdr.version, "bin header version");
+    CHECK(hdr2.pad_offset == hdr.pad_offset, "bin header offset");
+    CHECK(hdr2.file_mode == hdr.file_mode, "bin header file_mode");
+    CHECK(hdr2.file_size == hdr.file_size, "bin header file_size");
+    CHECK(memcmp(hdr2.pad_chksum, hdr.pad_chksum, OTPPAD_CHKSUM_BIN_LEN) == 0,
+          "bin header chksum");
+    CHECK(otppad_bin_is_magic((const unsigned char *)hdr2.magic, 4),
+          "bin is_magic");
+}
+
+static void test_state(void) {
+    const char *dir = "test_state_dir.tmp";
+    mkdir(dir, 0755);
+    const char *chksum =
+        "333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e";
+
+    uint64_t off;
+    CHECK(otppad_state_read(dir, chksum, &off) != 0, "state read missing fails");
+
+    CHECK(otppad_state_write(dir, chksum, 42) == 0, "state write");
+    CHECK(otppad_state_read(dir, chksum, &off) == 0, "state read");
+    CHECK(off == 42, "state value");
+
+    CHECK(otppad_state_write(dir, chksum, 1000) == 0, "state overwrite");
+    CHECK(otppad_state_read(dir, chksum, &off) == 0, "state read 2");
+    CHECK(off == 1000, "state value 2");
+
+    /* cleanup */
+    char path[1024];
+    snprintf(path, sizeof(path), "%s/%s.state", dir, chksum);
+    unlink(path);
+    rmdir(dir);
+}
+
+static void test_checksum(void) {
+    /* Build a tiny pad: 64 bytes, first 32 are the "key", rest arbitrary. */
+    const char *dir = "test_chksum_dir.tmp";
+    const char *chksum_expected =
+        "333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e";
+    mkdir(dir, 0755);
+
+    /* Use the real test pad if it exists; otherwise skip this test. */
+    const char *real_pad =
+        "/media/user/Music/pads/333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e.pad";
+    FILE *fp = fopen(real_pad, "rb");
+    if (!fp) {
+        printf("ok: checksum test skipped (no real pad at %s)\n", real_pad);
+        rmdir(dir);
+        return;
+    }
+    fclose(fp);
+
+    char chk[OTPPAD_CHKSUM_HEX_LEN + 1];
+    CHECK(otppad_checksum(real_pad, chk) == 0, "checksum computes");
+    CHECK(strcmp(chk, chksum_expected) == 0,
+          "checksum matches expected (bit-compatible with otp)");
+
+    rmdir(dir);
+}
+
+int main(void) {
+    test_xor();
+    test_base64();
+    test_padding();
+    test_armor();
+    test_bin_header();
+    test_state();
+    test_checksum();
+
+    if (failures == 0) {
+        printf("\nALL TESTS PASSED\n");
+        return 0;
+    }
+    printf("\n%d TEST(S) FAILED\n", failures);
+    return 1;
+}

packaging/qubes/allow_nostr_dom0.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+# Run in dom0 to allow the "nostr" qube to call n_signer without a Qubes popup.
+
+set -euo pipefail
+
+POLICY_FILE="/etc/qubes/policy.d/40-nsigner.policy"
+SIGNER_QUBE="nostr_signer"
+CALLER_QUBE="nostr"
+SIGNER_TAG="nsigner-signer"
+
+echo "Installing n_signer qrexec policy..."
+sudo mkdir -p /etc/qubes/policy.d
+sudo tee "$POLICY_FILE" >/dev/null <<EOF
+# Qubes OS qrexec policy for nsigner
+qubes.NsignerRpc * ai @tag:${SIGNER_TAG} allow target=${SIGNER_QUBE}
+qubes.NsignerRpc * ${CALLER_QUBE} @tag:${SIGNER_TAG} allow target=${SIGNER_QUBE}
+qubes.NsignerRpc * @anyvm @tag:${SIGNER_TAG} ask default_target=${SIGNER_QUBE}
+qubes.NsignerRpc * @anyvm @anyvm deny
+EOF
+sudo chmod 0644 "$POLICY_FILE"
+
+echo "Tagging ${SIGNER_QUBE} as ${SIGNER_TAG}..."
+qvm-tags "$SIGNER_QUBE" add "$SIGNER_TAG"
+
+echo
+echo "Installed policy:"
+sudo cat "$POLICY_FILE"
+echo
+echo "Tags on ${SIGNER_QUBE}:"
+qvm-tags "$SIGNER_QUBE" list
+echo
+echo "Done. Calls from ${CALLER_QUBE} to ${SIGNER_QUBE} are now allowed without a Qubes popup."

plans/cyd_algorithm_api_upgrade.md

@@ -0,0 +1,306 @@
+# Plan: Bring `firmware/cyd_esp32_2432s028` Up to Date with the Algorithm-Based API
+
+## Context
+
+The main project ([`src/dispatcher.c`](../src/dispatcher.c)) has fully migrated to the
+algorithm-based API documented in [`README.md`](../README.md) §4. The migration is marked
+COMPLETED in [`plans/legacy_verb_aliases.md`](../plans/legacy_verb_aliases.md): legacy verb
+names are gone from the wire protocol, implementation, tests, clients, and docs.
+
+The CYD firmware at [`firmware/cyd_esp32_2432s028/main/main.c`](../firmware/cyd_esp32_2432s028/main/main.c)
+was **not** updated and still speaks the **legacy verb API**:
+
+| Firmware verb (current) | Main-project verb (target) |
+|--------------------------|----------------------------|
+| `get_public_key` (+ `nostr_index`) | split → `get_public_key` (+ `algorithm`) **and** `nostr_get_public_key` (+ `nostr_index`) |
+| `sign_event` | `nostr_sign_event` |
+| `nip04_encrypt` / `nip04_decrypt` | `nostr_nip04_encrypt` / `nostr_nip04_decrypt` |
+| `nip44_encrypt` / `nip44_decrypt` | `nostr_nip44_encrypt` / `nostr_nip44_decrypt` |
+| _(missing)_ | `sign`, `verify`, `encapsulate`, `decapsulate`, `derive_shared_secret`, `derive`, `encrypt`/`decrypt` (otp), `nostr_mine_event` |
+
+### Good news: the crypto primitives already exist
+
+The firmware already has every underlying primitive needed — only the **dispatch layer**
+in [`main.c`](../firmware/cyd_esp32_2432s028/main/main.c) is stale:
+
+- [`key_derivation.h`](../firmware/cyd_esp32_2432s028/main/key_derivation.h): `derive_nostr_key_index`, `derive_ed25519_key`, `derive_x25519_key`, `derive_ml_dsa_65_key`, `derive_slh_dsa_128s_key`, `derive_ml_kem_768_key`, `schnorr_sign32`, `ed25519_sign32`
+- [`pq_crypto_firmware.h`](../firmware/cyd_esp32_2432s028/main/pq_crypto_firmware.h): `fw_pq_ml_dsa_65_sign/verify`, `fw_pq_slh_dsa_128s_sign/verify`, `fw_pq_ml_kem_768_encaps/decaps`
+- [`nostr_core_lib`](../resources/nostr_core_lib) nip004/nip044 already linked for the Nostr verbs
+
+### `key_id` convention
+
+The main project defines `key_id` as the **first 16 hex characters of the public key**
+(see [`src/dispatcher.c`](../src/dispatcher.c) ~line 1788). The firmware must match this
+so clients can correlate keys across targets.
+
+## Scope
+
+**Target:** [`firmware/cyd_esp32_2432s028`](../firmware/cyd_esp32_2432s028) only.
+The feather_s3_tft firmware is explicitly out of scope for this pass (it has the same gap
+but will be handled separately).
+
+## Architecture: dispatch flow after upgrade
+
+```mermaid
+flowchart TD
+    A[recv frame] --> B[parse JSON-RPC]
+    B --> C{auth envelope}
+    C -->|fail| Z[auth error]
+    C -->|ok| D{method}
+    D -->|nostr_*| E[Nostr verb branch<br/>secp256k1 NIP-06<br/>nostr_index selector]
+    D -->|alg verb| F[Algorithm verb branch<br/>algorithm + index selector]
+    E --> G[derive_request_key<br/>nostr_index]
+    F --> H{algorithm}
+    H -->|secp256k1| H1[derive_nostr_key_index]
+    H -->|ed25519| H2[derive_ed25519_key]
+    H -->|x25519| H3[derive_x25519_key]
+    H -->|ml-dsa-65| H4[derive_ml_dsa_65_key]
+    H -->|slh-dsa-128s| H5[derive_slh_dsa_128s_key]
+    H -->|ml-kem-768| H6[derive_ml_kem_768_key]
+    H -->|otp| H7[bound pad]
+    G --> I[enforcement matrix check]
+    H1 --> I
+    H2 --> I
+    H3 --> I
+    H4 --> I
+    H5 --> I
+    H6 --> I
+    H7 --> I
+    I -->|reject 1010| Z
+    I -->|ok| J[approval prompt]
+    J --> K[execute verb]
+    K --> L[structured result JSON<br/>algorithm + key_id + field]
+```
+
+## Implementation Steps
+
+### 1. Add algorithm-name parsing helpers (`main.c`)
+
+Add a small enum + parser mirroring the main project's algorithm set:
+
+```c
+typedef enum {
+    FW_ALG_SECP256K1 = 0,
+    FW_ALG_ED25519,
+    FW_ALG_X25519,
+    FW_ALG_ML_DSA_65,
+    FW_ALG_SLH_DSA_128S,
+    FW_ALG_ML_KEM_768,
+    FW_ALG_OTP,
+    FW_ALG_UNKNOWN
+} fw_alg_t;
+```
+
+- `parse_algorithm_from_options(cJSON *options, fw_alg_t *out_alg, uint32_t *out_index)`
+  — reads `algorithm` (string) and `index` (number, default 0) from the trailing options
+  object in `params`.
+- `fw_alg_name(fw_alg_t)` → canonical string (`"secp256k1"`, `"ed25519"`, …) for response
+  JSON.
+- Keep the existing `parse_nostr_index_from_params()` for the `nostr_*` verbs.
+
+### 2. Add a unified algorithm-key derivation + `key_id` helper
+
+Add `derive_alg_key(fw_alg_t alg, uint32_t index, ...)` that dispatches to the right
+`derive_*_key` function and produces:
+- the raw private key bytes (when applicable),
+- the public key hex,
+- the `key_id` (first 16 hex chars of the public key).
+
+PQ algorithms have large key buffers (ml-dsa-65 sk = 4032 B, ml-kem-768 sk = 2400 B).
+Allocate these as **static** buffers (not on the stack) and `secure_memzero` after use,
+matching the existing `s_privkey`/`s_pubkey` pattern. SLH-DSA-128s keygen is slow
+(5–30 s) — log a warning and show a "deriving key…" UI screen before calling it.
+
+### 3. Add a structured-result builder
+
+Add `build_alg_result_json(const char *alg_name, const char *key_id_16hex, const char *field_name, const char *field_value)` → returns a JSON string like
+`{"algorithm":"ed25519","key_id":"<16hex>","public_key":"<hex>"}`. This mirrors
+[`build_alg_result_json`](../src/dispatcher.c:861) in the main dispatcher.
+
+### 4. Add the enforcement matrix
+
+Add `enforce_alg_verb(fw_alg_t alg, const char *verb)` returning 0 / `1010`, matching
+[`README.md`](../README.md) §4.3 enforcement matrix:
+
+| Verb | Valid algorithms |
+|------|------------------|
+| `sign` / `verify` | secp256k1, ed25519, ml-dsa-65, slh-dsa-128s |
+| `encapsulate` / `decapsulate` | ml-kem-768 |
+| `derive_shared_secret` | x25519 |
+| `derive` | secp256k1 |
+| `encrypt` / `decrypt` | otp |
+| `get_public_key` | all key-deriving algorithms |
+
+Reject any unlisted pair with
+`{"error":{"code":1010,"message":"algorithm_not_supported_for_verb"}}`.
+
+### 5. Rename the Nostr verbs (in-place, no compat shim)
+
+In the dispatch `if/else if` chain in [`main.c`](../firmware/cyd_esp32_2432s028/main/main.c)
+~lines 836–1230:
+
+- `get_public_key` (nostr_index branch) → `nostr_get_public_key`
+- `sign_event` → `nostr_sign_event`
+- `nip04_encrypt` → `nostr_nip04_encrypt`
+- `nip04_decrypt` → `nostr_nip04_decrypt`
+- `nip44_encrypt` → `nostr_nip44_encrypt`
+- `nip44_decrypt` → `nostr_nip44_decrypt`
+
+The `nostr_get_public_key` verb should also honor the `format` option
+(`"structured"` → `{"algorithm":"secp256k1","public_key":"<hex>","key_id":"<16hex>"}`,
+default → bare 64-hex pubkey string), matching the main project.
+
+### 6. Add the algorithm-based `get_public_key` verb
+
+`get_public_key` with `algorithm` + `index` → derive the key, return structured JSON:
+`{"algorithm":"<alg>","public_key":"<hex>","key_id":"<16hex>"}`. For PQ algorithms the
+`public_key` is the full PQClean pubkey hex (1952 B for ml-dsa-65, 1184 B for ml-kem-768,
+32 B for slh-dsa-128s) — ensure `s_response_buf` (currently 2048 B) is large enough, or
+emit via `cJSON_PrintUnformatted` into a larger static buffer.
+
+### 7. Add `sign` and `verify` (algorithm-based)
+
+- `sign`: params `[<message_hex>, {algorithm, index, scheme?}]`. `scheme` is
+  secp256k1-only (`"schnorr"` default / `"ecdsa"`). For ed25519 use `ed25519_sign32`
+  (note: ed25519 signs the raw 32-byte message, not a pre-hash — match main project
+  behavior). For ml-dsa-65 / slh-dsa-128s use `fw_pq_*_sign`. Response:
+  `{"algorithm":"<alg>","key_id":"<16hex>","signature":"<hex>"}`.
+- `verify`: params `[<message_hex>, <signature_hex>, {algorithm, index, scheme?}]`.
+  Derive the signer's own pubkey and verify against it. Response:
+  `{"valid":true,"algorithm":"<alg>"}`.
+
+### 8. Add `encapsulate` / `decapsulate` (ml-kem-768)
+
+- `encapsulate`: params `[<peer_pubkey_hex>, {algorithm:"ml-kem-768"}]` →
+  `fw_pq_ml_kem_768_encaps` →
+  `{"ciphertext":"<hex>","shared_secret":"<hex>","algorithm":"ml-kem-768"}`.
+- `decapsulate`: params `[<ciphertext_hex>, {algorithm:"ml-kem-768", index}]` → derive
+  kem keypair, `fw_pq_ml_kem_768_decaps` →
+  `{"shared_secret":"<hex>","algorithm":"ml-kem-768"}`.
+
+### 9. Add `derive_shared_secret` (x25519)
+
+params `[<peer_pubkey_hex>, {algorithm:"x25519", index}]` → derive x25519 keypair,
+compute X25519 ECDH via mbedtls →
+`{"shared_secret":"<hex>","algorithm":"x25519"}`.
+
+### 10. Add `derive` (secp256k1 HMAC-SHA256)
+
+params `[<data>, {algorithm:"secp256k1", index}]` (`index` **required**) → derive
+secp256k1 privkey, compute `HMAC-SHA256(privkey, data)` via mbedtls →
+`{"algorithm":"secp256k1","key_id":"<16hex>","digest":"<64hex>"}`. See
+[`plans/derive_hmac.md`](../plans/derive_hmac.md) for the spec.
+
+### 11. Add `nostr_mine_event` (PoW)
+
+params `[<event_json>, {nostr_index, difficulty, timeout_sec, threads?}]`. Reuse
+`build_signed_event_json` but iterate nonce in the event's `tags` until the leading-zero
+bits of the event id meet `difficulty`. ESP32 is slow — cap `threads` at 1 and enforce a
+firm `timeout_sec` (default 30). Show a "mining…" UI screen. If timeout, return error
+`1008 mining_failed`. This mirrors [`src/miner.c`](../src/miner.c).
+
+### 12. Add `encrypt` / `decrypt` (otp)
+
+The main project binds a pad from `--otp-pad-dir` + `--otp-pad` (a USB file). The CYD has
+no filesystem pad source. **Decision: derive the OTP pad from the mnemonic seed** via a
+SHAKE-256 / HKDF expansion keyed on `algorithm:"otp"` so the pad is deterministic per
+mnemonic and advances monotonically across requests (offset stored in a static variable,
+reported in every response). This keeps the wire contract identical (`encrypt`/`decrypt`
+with `algorithm:"otp"`, `encoding:"ascii"|""binary""`) while fitting the embedded
+constraint. Document this divergence in [`firmware/README.md`](../firmware/README.md).
+
+### 13. Bump `FIRMWARE_VERSION` and update `firmware/README.md`
+
+- `FIRMWARE_VERSION` "0.0.1" → "0.0.2" (algorithm-based API).
+- Document the new verb table, the OTP pad-derivation divergence, and the SLH-DSA-128s
+  latency warning.
+
+### 14. Update CYD-targeting examples / clients
+
+Audit and update any example or client that speaks to the CYD over UART/Web-Serial and
+uses legacy verb names:
+- [`examples/feather_get_public_key.py`](../examples/feather_get_public_key.py) and
+  [`examples/feather_sign_event.py`](../examples/feather_sign_event.py) (feather-targeting
+  but the wire protocol is shared — note in README they need `nostr_` prefixes for CYD
+  after this change; leave feather examples alone since feather is out of scope, but add a
+  CYD-specific example pair if none exists).
+- [`client/`](../client/) demos already use the new verbs (per
+  [`plans/legacy_verb_aliases.md`](../plans/legacy_verb_aliases.md)) — verify no CYD-specific
+  legacy calls remain.
+
+### 15. Add a CYD Web Serial test page covering all algorithms
+
+The existing [`examples/feather_webusb_demo.html`](../examples/feather_webusb_demo.html) is
+**WebUSB-only** (feather's native USB) and uses the **legacy verbs**. The CYD's CH340
+bridge (`1a86:7523`) is not a WebUSB device — it exposes a serial port, so the browser
+transport is **Web Serial** (`navigator.serial`), Chromium-only.
+
+Create [`examples/cyd_webserial_demo.html`](../examples/cyd_webserial_demo.html) — a
+single-file, dependency-light test page that:
+
+**Transport:**
+- `navigator.serial.requestPort()` → `port.open({ baudRate: 115200 })` (matches
+  [`uart_transport.c`](../firmware/cyd_esp32_2432s028/main/uart_transport.c) UART_BAUD_RATE).
+- Same 4-byte big-endian length-prefix frame format as the feather demo
+  ([`be32()`](../examples/feather_webusb_demo.html:256), read loop reassembling frames).
+- Read via a `ReadableStream` reader + length-prefix reassembly (Web Serial is stream-based,
+  not packet-based like WebUSB `transferIn`).
+- Same auth-envelope construction (kind 27235, `nsigner_method` / `nsigner_body_hash` tags,
+  schnorr sign with a demo caller key) — reuse the
+  [`buildAuth()`](../examples/feather_webusb_demo.html:279) logic verbatim.
+
+**UI sections (one card per verb family, all algorithms):**
+1. **Connect** — Connect Web Serial button + status.
+2. **Get Public Key** — algorithm dropdown (`secp256k1`, `ed25519`, `x25519`, `ml-dsa-65`,
+   `slh-dsa-128s`, `ml-kem-768`) + index → `get_public_key`. Also a `nostr_get_public_key`
+   card with `nostr_index` + `format` (bare / structured) toggle.
+3. **Sign / Verify** — algorithm dropdown (sig algs only) + index + `scheme` (schnorr/ecdsa,
+   secp256k1-only) + message hex → `sign`; then `verify` with the returned signature.
+4. **KEM (ml-kem-768)** — `encapsulate` with a peer pubkey (or self-pubkey from
+   `get_public_key`) → ciphertext + shared secret; `decapsulate` with that ciphertext →
+   shared secret (confirm match).
+5. **X25519** — `derive_shared_secret` with peer pubkey.
+6. **Derive (HMAC)** — `derive` with data string + index → 64-hex digest.
+7. **Nostr Sign Event** — `nostr_sign_event` (kind 1) with `nostr_index`.
+8. **Nostr Mine Event** — `nostr_mine_event` with difficulty + timeout (low default, e.g.
+   difficulty 4) — warn it's slow on ESP32.
+9. **NIP-04 / NIP-44** — `nostr_nip04_encrypt`/`decrypt`, `nostr_nip44_encrypt`/`decrypt`
+   with `nostr_index`.
+10. **OTP** — `encrypt` / `decrypt` with `algorithm:"otp"`, `encoding` toggle
+    (ascii/binary), base64 plaintext.
+
+Each card shows the raw JSON-RPC request and response in a `<pre>` so the wire format is
+visible. Reuse the feather demo's CSS (dark theme, cards, `.mono` log) for consistency.
+
+**Link it from [`firmware/README.md`](../firmware/README.md)** in the CYD section (the
+"Quick validation" / Web Serial path), since the current README only points at the
+feather WebUSB demo.
+
+### 16. Verification
+
+- `idf.py build` in [`firmware/cyd_esp32_2432s028`](../firmware/cyd_esp32_2432s028) compiles
+  clean.
+- Flash to the connected CYD board (CH340 on `/dev/ttyUSB0`) and smoke-test each verb:
+  - Primary path: open [`examples/cyd_webserial_demo.html`](../examples/cyd_webserial_demo.html)
+    in Chrome/Edge, connect via Web Serial, exercise every card.
+  - Secondary path: a small Python script over `/dev/ttyUSB0` for headless confirmation.
+  - Cover: `get_public_key` (each algorithm), `sign`/`verify` (each sig alg),
+    `encapsulate`/`decapsulate`, `derive_shared_secret`, `derive`,
+    `nostr_get_public_key`, `nostr_sign_event`, `nostr_nip04_encrypt`/`decrypt`,
+    `nostr_nip44_encrypt`/`decrypt`, `nostr_mine_event` (low difficulty),
+    `encrypt`/`decrypt` (otp).
+  - Confirm `key_id` matches the first 16 hex of the returned pubkey for every alg.
+  - Confirm an invalid `(verb, algorithm)` pair returns code 1010.
+- `grep -rn "sign_event\|nip04_encrypt\|nip04_decrypt\|nip44_encrypt\|nip44_decrypt"
+  firmware/cyd_esp32_2432s028/` returns no matches (legacy names gone).
+
+## Open questions / decisions baked in
+
+- **OTP pad source:** derived from mnemonic (no USB pad on CYD). Documented divergence.
+- **`nostr_mine_event`:** implemented, single-threaded, hard 30 s default timeout, with a
+  "mining…" UI screen. Not stubbed — the main project has it and the user asked to bring
+  the firmware up to date.
+- **No legacy-verb compat shim:** matches the main project's policy
+  ([`plans/legacy_verb_aliases.md`](../plans/legacy_verb_aliases.md) — "No backward-
+  compatibility shim is needed").
+- **feather_s3_tft not touched** in this pass.

plans/derive_hmac.md

@@ -0,0 +1,538 @@
+# Plan: `derive` verb — HMAC-SHA256 from a derived private key
+
+## Problem
+
+sovereign_browser stores bookmarks as NIP-51 kind 30003 parameterized-replaceable
+events, one per folder. The `d` tag must be a **deterministic function of the
+folder path** so that multiple devices editing the same logical folder produce
+the same `d` tag and the relay's NIP-33 replaceability keeps only the latest
+event. A random `d` tag would break cross-device sync (each device would emit a
+new event for the same folder, with no dedup).
+
+The browser currently computes the `d` tag locally as:
+
+```
+hmac_key = HMAC-SHA256(privkey, "sovereign-browser/bookmarks-folder-id-v1")
+d        = HMAC-SHA256(hmac_key, path)   → 64 hex chars
+```
+
+This only works when the privkey is in browser memory (login methods
+`generate` / `import`). When the signer is the **nsigner remote backend**, the
+privkey is held by n_signer and never exposed to the browser, so
+[`compute_hmac_key()`](../sovereign_browser/src/bookmarks.c:194) returns -1 and
+[`path_to_d_tag`](../sovereign_browser/src/bookmarks.c:221) falls back to
+**plaintext** path d tags — a privacy regression that leaks folder names to
+relays.
+
+## Decision
+
+Add a single new algorithm-based verb to n_signer:
+
+```
+derive(data) = HMAC-SHA256(privkey, data)   → 64 hex chars
+```
+
+- `privkey` is the secp256k1 private key derived on demand from the mnemonic at
+  `(algorithm: "secp256k1", index: N)` via the existing
+  [`alg_key_cache_derive`](src/key_store.c:1624).
+- `data` is an arbitrary caller-supplied UTF-8 string (or hex-encoded bytes).
+- Returns the 32-byte HMAC digest as 64 lowercase hex chars.
+
+This is a **single-step** scheme. The browser will switch from its two-step
+scheme to single-step by concatenating the label and path into the data string
+before calling `derive`:
+
+```
+d = derive("sovereign-browser/bookmarks-folder-id-v1:" + path)
+  = HMAC-SHA256(privkey, "sovereign-browser/bookmarks-folder-id-v1:" + path)
+```
+
+The label prefix provides domain separation (so the same path used by a
+different application produces a different d tag). This is cryptographically
+equivalent to the two-step scheme for the privacy properties that matter
+(determinism, opacity, per-user-ness, no label/path recovery from the hash).
+
+### Why single-step over two-step
+
+1. **Generic primitive.** `derive(data) = HMAC(privkey, data)` is a clean
+   building block any caller can use for any purpose — bookmark d tags,
+   per-resource identifiers, per-app secrets, etc. A two-step verb bakes a
+   specific construction into the RPC.
+2. **No state across calls.** A two-step scheme where the browser calls
+   `derive(LABEL)` then `derive(path)` cannot work because step 2 needs
+   `hmac_key` as the HMAC **key**, not `privkey` — and a privkey-keyed-only
+   primitive always uses `privkey` as the key. Single-step avoids this entirely.
+3. **Migration cost is acceptable.** The browser already has a migration pattern
+   for legacy d tags (detect on load, re-publish with new d tag, kind-5 delete
+   old). The same pattern handles the two-step → single-step transition.
+
+### Migration of existing two-step bookmark events
+
+Existing bookmark events on relays have `d = HMAC-SHA256(HMAC-SHA256(privkey, LABEL), path)`.
+After the switch, the browser will compute `d = HMAC-SHA256(privkey, LABEL + ":" + path)`,
+which is a different hash. On next `bookmarks_init`:
+
+1. Fetch all kind 30003 events as today.
+2. For each event, decrypt content, read `path`.
+3. Compute the **new** single-step d tag for that path.
+4. If the event's `d` tag does **not** match the new d tag (i.e. it's an old
+   two-step tag), re-publish the event with the new d tag and emit a kind-5
+   deletion for the old event id.
+5. This is the same logic the browser already uses for legacy plaintext d tags
+   (see [`plans/bookmarks-tree-view.md`](../sovereign_browser/plans/bookmarks-tree-view.md:61)
+   §"Why this is safe and nostr-ish" — "Legacy events with plaintext `d = "General"`
+   will be detected on load... decrypted, and re-published in the new HMAC-`d`
+   format; the old events get a kind 5 deletion.").
+
+The migration is **self-healing**: each device migrates the events it sees, and
+once all devices have upgraded, no old two-step d tags remain on relays.
+
+## n_signer changes
+
+### 1. New verb constant
+
+[`src/enforcement.c`](src/enforcement.c:209) (and the headerless decls block in
+every other src file that carries it):
+
+```c
+#define VERB_DERIVE  "derive"
+```
+
+Add it to the algorithm-based verb set in
+[`is_algorithm_verb()`](src/dispatcher.c:817):
+
+```c
+return (strcmp(method, VERB_SIGN) == 0 ||
+        strcmp(method, VERB_VERIFY) == 0 ||
+        strcmp(method, VERB_ENCAPSULATE) == 0 ||
+        strcmp(method, VERB_DECAPSULATE) == 0 ||
+        strcmp(method, VERB_DERIVE_SHARED) == 0 ||
+        strcmp(method, VERB_GET_PUBLIC_KEY) == 0 ||
+        strcmp(method, VERB_DERIVE) == 0);
+```
+
+### 2. Enforcement
+
+[`enforce_verb_algorithm()`](src/enforcement.c:765): `derive` is valid for
+`secp256k1` only (the privkey is a 32-byte scalar suitable as an HMAC key; PQ
+private keys are not). Add:
+
+```c
+/* derive: HMAC-SHA256(privkey, data). secp256k1 only (32-byte scalar key). */
+if (strcmp(verb, VERB_DERIVE) == 0) {
+    if (alg == CRYPTO_ALG_SECP256K1) {
+        return ENFORCE_OK;
+    }
+    return ENFORCE_ERR_ALGORITHM;
+}
+```
+
+### 3. Dispatcher handler
+
+[`handle_algorithm_verb()`](src/dispatcher.c:880): add a new branch after the
+existing `derive_shared_secret` branch. Request shape:
+
+```json
+{"id":"...","method":"derive","params":["<data>",{"algorithm":"secp256k1","index":0}]}
+```
+
+- `params[0]` = the data string (UTF-8).
+- `options.algorithm` = `"secp256k1"` (required).
+- `options.index` = derivation index (**required** — no default). The dispatcher
+  returns error `-32602 missing_index` if `index` is absent.
+
+Handler:
+
+```c
+/* ---- derive (secp256k1 HMAC-SHA256) ---- */
+if (strcmp(method, VERB_DERIVE) == 0) {
+    cJSON *data_item = cJSON_GetArrayItem(params_item, 0);
+    cJSON *index_item = NULL;
+    const char *data_str;
+    const unsigned char *priv;
+    unsigned char mac[32];
+    char mac_hex[65];
+    char *result;
+
+    if (!cJSON_IsString(data_item) || data_item->valuestring == NULL) {
+        return make_error_response(id_str, -32602, "invalid_params");
+    }
+    data_str = data_item->valuestring;
+
+    /* index is required for derive (no default). */
+    if (!cJSON_IsObject(options_item)) {
+        return make_error_response(id_str, -32602, "missing_index");
+    }
+    index_item = cJSON_GetObjectItemCaseSensitive(options_item, "index");
+    if (!cJSON_IsNumber(index_item)) {
+        return make_error_response(id_str, -32602, "missing_index");
+    }
+    index = index_item->valueint;
+
+    /* Derive the secp256k1 key on demand. */
+    if (alg_key_cache_derive(ctx->alg_key_cache, ctx->mnemonic, alg, index) != 0) {
+        return make_error_response(id_str, -32602, "key_derivation_failed");
+    }
+    key_entry = alg_key_cache_get(ctx->alg_key_cache, alg, index);
+    if (key_entry == NULL || !key_entry->valid) {
+        return make_error_response(id_str, -32602, "key_derivation_failed");
+    }
+    priv = (const unsigned char *)key_entry->private_key.data;
+
+    /* HMAC-SHA256(privkey, data) */
+    if (nostr_hmac_sha256(priv, sz->priv_key_len,
+                           (const unsigned char *)data_str, strlen(data_str),
+                           mac) != 0) {
+        return make_error_response(id_str, -32602, "hmac_failed");
+    }
+
+    nostr_bytes_to_hex(mac, 32, mac_hex);
+    secure_memzero(mac, sizeof(mac));
+
+    result = build_alg_result_json(alg_name, key_entry->key_id,
+                                     "digest", mac_hex);
+    if (result == NULL) {
+        return make_error_response(id_str, -32602, "invalid_params");
+    }
+    return make_success_response(id_str, result);
+}
+```
+
+`nostr_hmac_sha256` is already available via `<nostr_core/utils.h>` (linked into
+n_signer through nostr_core_lib). `secure_memzero` clears the stack-local mac.
+
+Response:
+
+```json
+{"id":"...","result":"{\"algorithm\":\"secp256k1\",\"key_id\":\"<16hex>\",\"digest\":\"<64hex>\"}"}
+```
+
+### 4. Headerless decls
+
+The `VERB_DERIVE` define must be added to the `NSIGNER_HEADERLESS_DECLS_BEGIN`
+block in every file that carries it. The same block already exists in:
+- [`src/dispatcher.c`](src/dispatcher.c:209)
+- [`src/enforcement.c`](src/enforcement.c:210)
+- [`src/key_store.c`](src/key_store.c:208)
+- [`src/main.c`](src/main.c:215)
+- [`src/policy.c`](src/policy.c:209)
+- [`src/selector.c`](src/selector.c:209)
+- [`src/server.c`](src/server.c:215)
+- [`src/role_table.c`](src/role_table.c:212)
+- [`src/mnemonic.c`](src/mnemonic.c:209)
+- [`src/secure_mem.c`](src/secure_mem.c:211)
+- [`src/socket_name.c`](src/socket_name.c:211)
+- [`src/pq_crypto.c`](src/pq_crypto.c:222)
+- [`tests/test_*.c`](tests/) (each test file that carries the block)
+
+### 5. Tests
+
+Add a test in [`tests/test_algorithm_api.c`](tests/test_algorithm_api.c) (or a
+new `tests/test_derive.c`):
+
+1. Load a known mnemonic, derive secp256k1 key at index 0.
+2. Call `derive` with `data = "test-data"`.
+3. Independently compute `HMAC-SHA256(privkey, "test-data")` using
+   `nostr_hmac_sha256` and compare to the RPC result.
+4. Assert determinism: same input → same digest.
+5. Assert opaqueness: different inputs → different digests.
+6. Assert rejection for non-secp256k1 algorithms (e.g. `algorithm: "ed25519"`
+   → error 1010 `algorithm_not_supported_for_verb`).
+7. Assert rejection when mnemonic is not loaded (error 1006).
+
+### 6. Documentation
+
+- [`README.md`](README.md) §4.3 verb table: add `derive` row.
+- [`README.md`](README.md) §4.4 algorithms: note `derive` is secp256k1-only.
+- [`api.md`](api.md): add worked example.
+- [`client/README.md`](client/README.md): add `derive` to the verb table.
+- [`documents/CLIENT_IMPLEMENTATION.md`](documents/CLIENT_IMPLEMENTATION.md):
+  add `derive` to the algorithm-based verb list with example request/response.
+
+## nostr_core_lib client changes
+
+[`nostr_core_lib/nostr_core/nostr_signer.h`](../sovereign_browser/nostr_core_lib/nostr_core/nostr_signer.h)
+and
+[`nostr_core_lib/nostr_core/nostr_signer.c`](../sovereign_browser/nostr_core_lib/nostr_core/nostr_signer.c):
+
+Add a new high-level API:
+
+```c
+/* Compute HMAC-SHA256(privkey, data) using the signer's derived secp256k1
+ * private key. Returns the 32-byte digest as 64 lowercase hex chars + NUL.
+ * For the local backend, computes directly. For the nsigner remote backend,
+ * calls the "derive" verb.
+ * data must be a NUL-terminated UTF-8 string.
+ * Returns NOSTR_SUCCESS or an error code. */
+int nostr_signer_derive_hmac(nostr_signer_t* signer,
+                             const char* data,
+                             char out_digest_hex[65]);
+```
+
+### Local backend
+
+```c
+static int signer_local_derive_hmac(nostr_signer_t* signer,
+                                    const char* data,
+                                    char out_digest_hex[65]) {
+    unsigned char mac[32];
+    if (!signer || !data || !out_digest_hex) {
+        return NOSTR_ERROR_INVALID_INPUT;
+    }
+    if (nostr_hmac_sha256(signer->u.local.private_key, 32,
+                           (const unsigned char*)data, strlen(data),
+                           mac) != 0) {
+        return NOSTR_ERROR_CRYPTO_FAILED;
+    }
+    nostr_bytes_to_hex(mac, 32, out_digest_hex);
+    memset(mac, 0, sizeof(mac));
+    return NOSTR_SUCCESS;
+}
+```
+
+### Remote (nsigner) backend
+
+```c
+static int signer_remote_derive_hmac(nostr_signer_t* signer,
+                                     const char* data,
+                                     char out_digest_hex[65]) {
+    cJSON* params;
+    cJSON* result = NULL;
+    const char* result_str;
+    int rc;
+
+    params = cJSON_CreateArray();
+    if (params == NULL) return NOSTR_ERROR_MEMORY_FAILED;
+    cJSON_AddItemToArray(params, cJSON_CreateString(data));
+
+    params = signer_remote_params_with_selector(params,
+              signer->u.remote.role,
+              signer->u.remote.has_nostr_index,
+              signer->u.remote.nostr_index);
+    if (params == NULL) return NOSTR_ERROR_MEMORY_FAILED;
+
+    /* The remote derive verb needs algorithm:"secp256k1" in the options. */
+    {
+        cJSON* opts = cJSON_GetArrayItem(params, cJSON_GetArraySize(params) - 1);
+        if (opts != NULL && cJSON_IsObject(opts)) {
+            cJSON_AddStringToObject(opts, "algorithm", "secp256k1");
+        }
+    }
+
+    rc = nsigner_client_call(signer->u.remote.client, "derive", params, &result);
+    if (rc != NOSTR_SUCCESS) return rc;
+
+    /* result is a JSON string: {"algorithm":"secp256k1","key_id":"...","digest":"<64hex>"} */
+    if (!cJSON_IsString(result) || result->valuestring == NULL) {
+        cJSON_Delete(result);
+        return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+    }
+    {
+        cJSON* parsed = cJSON_Parse(result->valuestring);
+        cJSON* digest_item;
+        const char* digest_str;
+        cJSON_Delete(result);
+        if (parsed == NULL) return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+        digest_item = cJSON_GetObjectItemCaseSensitive(parsed, "digest");
+        if (!cJSON_IsString(digest_item) || digest_item->valuestring == NULL ||
+            strlen(digest_item->valuestring) != 64) {
+            cJSON_Delete(parsed);
+            return NOSTR_ERROR_NIP46_INVALID_RESPONSE;
+        }
+        digest_str = digest_item->valuestring;
+        memcpy(out_digest_hex, digest_str, 64);
+        out_digest_hex[64] = '\0';
+        cJSON_Delete(parsed);
+    }
+    return NOSTR_SUCCESS;
+}
+```
+
+**Note on the options object:** the existing
+`signer_remote_params_with_selector` appends a selector object as the last
+params element. For algorithm-based verbs, the selector object must also carry
+`algorithm` and `index`. The implementation must ensure the options object
+already exists (or create one) before adding `algorithm`. If
+`has_nostr_index` is false and `role` is empty, `signer_remote_params_with_selector`
+does not append an options object — in that case the derive handler must append
+one with just `algorithm`. This is a small extension to the helper or a local
+construction in `signer_remote_derive_hmac`.
+
+### Test
+
+[`nostr_core_lib/tests/nsigner_client_test.c`](../sovereign_browser/nostr_core_lib/tests/nsigner_client_test.c):
+add a test that calls `nostr_signer_derive_hmac` on a local signer with a known
+privkey + known data, and compares against a reference HMAC-SHA256 computed
+with `nostr_hmac_sha256` directly.
+
+## sovereign_browser changes
+
+### 1. Switch to single-step d tag
+
+[`src/bookmarks.c`](../sovereign_browser/src/bookmarks.c:194): replace
+`compute_hmac_key` + `path_to_d_tag` with a single function that calls the
+signer:
+
+```c
+/* New label prefix — domain-separated, baked into the data string. */
+#define BOOKMARKS_HMAC_KEY_LABEL "sovereign-browser/bookmarks-folder-id-v1"
+
+static char *path_to_d_tag(const char *path) {
+    if (path == NULL) path = "";
+
+    /* Build "LABEL:" + path */
+    char *data = g_strdup_printf("%s:%s", BOOKMARKS_HMAC_KEY_LABEL, path);
+    char digest_hex[65];
+    int rc;
+
+    rc = nostr_signer_derive_hmac(g_signer, data, digest_hex);
+    g_free(data);
+    if (rc != NOSTR_SUCCESS) {
+        /* No signer or derive failed — fall back to plaintext (read-only mode). */
+        return g_strdup(path);
+    }
+    return g_strdup(digest_hex);
+}
+```
+
+Remove `g_hmac_key`, `g_have_hmac_key`, `compute_hmac_key`, and the
+`g_privkey` / `g_have_privkey` state (the privkey is no longer needed in
+browser memory — the signer holds it). This is a **security improvement**: the
+browser no longer carries the privkey in its own RAM when using the nsigner
+backend.
+
+### 2. Migration of existing two-step d tags
+
+In `bookmarks_init` (or the relay-fetch load path), after decrypting an event
+and reading its `path`:
+
+1. Compute the new single-step d tag: `path_to_d_tag(path)`.
+2. Compare to the event's actual `d` tag.
+3. If they differ (old two-step tag), re-publish the event with the new d tag
+   and emit a kind-5 deletion for the old event id.
+
+This reuses the existing legacy-plaintext-d-tag migration logic. The detection
+predicate changes from "d tag is not 64 hex chars" to "d tag is 64 hex chars
+but does not match `path_to_d_tag(path)`".
+
+### 3. Remove privkey plumbing
+
+- [`src/main.c`](../sovereign_browser/src/main.c:69): remove `privkey_hex` from
+  `g_state` (or stop populating it).
+- [`src/main.c`](../sovereign_browser/src/main.c:652): remove the
+  `strncpy(g_state.privkey_hex, ...)` line.
+- [`src/bookmarks.h`](../sovereign_browser/src/bookmarks.h): change
+  `bookmarks_init` signature to drop the `privkey_hex` parameter.
+- All callers of `bookmarks_init` updated.
+
+### 4. Test
+
+[`tests/test_bookmarks_tree.c`](../sovereign_browser/tests/test_bookmarks_tree.c):
+update `path_to_d_tag` mirror to the single-step scheme:
+
+```c
+static char *path_to_d_tag(const unsigned char *privkey, const char *path) {
+    char *data = g_strdup_printf("%s:%s", LABEL, path ? path : "");
+    unsigned char mac[32];
+    char *hex;
+    if (nostr_hmac_sha256(privkey, 32,
+                           (const unsigned char*)data, strlen(data),
+                           mac) != 0) {
+        g_free(data);
+        return NULL;
+    }
+    g_free(data);
+    hex = g_strdup_printf(/* 64 hex chars */ ...);
+    return hex;
+}
+```
+
+All existing tests (determinism, opaqueness, 64-hex format, is_hmac_d_tag,
+per-user-ness, empty path) pass unchanged — they test properties, not the
+specific construction.
+
+## Architecture diagram
+
+```mermaid
+sequenceDiagram
+    participant Browser as sovereign_browser
+    participant Signer as n_signer
+    participant Relay as Nostr relay
+
+    Note over Browser: User saves bookmark to "Work/Projects/Secret"
+    Browser->>Signer: derive("sovereign-browser/bookmarks-folder-id-v1:Work/Projects/Secret", {algorithm:"secp256k1", index:0})
+    Signer->>Signer: alg_key_cache_derive(secp256k1, 0)
+    Signer->>Signer: HMAC-SHA256(privkey, data)
+    Signer-->>Browser: {"digest":"<64hex>"}
+    Browser->>Signer: nostr_nip44_encrypt(self_pubkey, JSON{path, bookmarks})
+    Signer-->>Browser: ciphertext
+    Browser->>Relay: publish kind 30003, d=<64hex>, content=<ciphertext>
+
+    Note over Browser: Other device starts up
+    Browser->>Relay: fetch kind 30003 by pubkey
+    Relay-->>Browser: events
+    Browser->>Signer: nostr_nip44_decrypt(self_pubkey, content)
+    Signer-->>Browser: JSON{path:"Work/Projects/Secret", bookmarks:[...]}
+    Note over Browser: path recovered from decrypted content, not from d tag
+```
+
+## File change summary
+
+### n_signer (this repo)
+
+| File | Change |
+|------|--------|
+| [`src/enforcement.c`](src/enforcement.c) | Add `VERB_DERIVE` define + `derive` case in `enforce_verb_algorithm` (secp256k1 only) |
+| [`src/dispatcher.c`](src/dispatcher.c) | Add `VERB_DERIVE` to `is_algorithm_verb` + `derive` branch in `handle_algorithm_verb` |
+| [`src/key_store.c`](src/key_store.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/main.c`](src/main.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/policy.c`](src/policy.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/selector.c`](src/selector.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/server.c`](src/server.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/role_table.c`](src/role_table.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/mnemonic.c`](src/mnemonic.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/secure_mem.c`](src/secure_mem.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/socket_name.c`](src/socket_name.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`src/pq_crypto.c`](src/pq_crypto.c) | Add `VERB_DERIVE` define (headerless decls) |
+| [`tests/test_algorithm_api.c`](tests/test_algorithm_api.c) | Add `derive` test cases |
+| [`README.md`](README.md) | Add `derive` to verb table + algorithm notes |
+| [`api.md`](api.md) | Add `derive` worked example |
+| [`client/README.md`](client/README.md) | Add `derive` to verb table |
+| [`documents/CLIENT_IMPLEMENTATION.md`](documents/CLIENT_IMPLEMENTATION.md) | Add `derive` section |
+
+### nostr_core_lib (sovereign_browser repo)
+
+| File | Change |
+|------|--------|
+| [`nostr_core/nostr_signer.h`](../sovereign_browser/nostr_core_lib/nostr_core/nostr_signer.h) | Add `nostr_signer_derive_hmac` declaration |
+| [`nostr_core/nostr_signer.c`](../sovereign_browser/nostr_core_lib/nostr_core/nostr_signer.c) | Add local + remote `derive_hmac` implementations |
+| [`tests/nsigner_client_test.c`](../sovereign_browser/nostr_core_lib/tests/nsigner_client_test.c) | Add `derive_hmac` test |
+
+### sovereign_browser
+
+| File | Change |
+|------|--------|
+| [`src/bookmarks.c`](../sovereign_browser/src/bookmarks.c) | Replace two-step `compute_hmac_key` + `path_to_d_tag` with single-step `path_to_d_tag` calling `nostr_signer_derive_hmac`; add two-step→single-step migration on load; remove `g_privkey`/`g_hmac_key` state |
+| [`src/bookmarks.h`](../sovereign_browser/src/bookmarks.h) | Drop `privkey_hex` param from `bookmarks_init` |
+| [`src/main.c`](../sovereign_browser/src/main.c) | Remove `privkey_hex` from `g_state` + stop populating it; update `bookmarks_init` call |
+| [`tests/test_bookmarks_tree.c`](../sovereign_browser/tests/test_bookmarks_tree.c) | Update `path_to_d_tag` mirror to single-step scheme |
+
+## Open questions
+
+1. **Should `derive` accept hex-encoded binary data, or only UTF-8 strings?**
+   Default: UTF-8 strings only (simpler, covers the bookmark use case). If a
+   caller needs binary data, they hex-encode it and we add a `data_encoding`
+   option later. Decision can be deferred.
+
+2. **`index` is required.** Unlike other algorithm-based verbs that default
+   `index` to 0, `derive` requires the caller to specify `index` explicitly.
+   This forces conscious selection of which derived key to use as the HMAC key,
+   avoiding accidental cross-identity d-tag collisions. The dispatcher returns
+   `-32602 missing_index` if `index` is absent.
+
+3. **Should `derive` be added to the `--preapprove` algorithm-based policy
+   syntax?**
+   Yes — it flows through the same `policy_check_algorithm` path as other
+   algorithm-based verbs. Operators can pre-approve
+   `caller=...,algorithm=secp256k1,index=0,verb=derive`. No code change needed
+   beyond the verb define; policy matching is by string.

plans/http_wss_listener.md

@@ -0,0 +1,274 @@
+# Plan: HTTP and WebSocket (WSS) Listener Modes for n_signer
+
+## Goal
+
+Add two new listener modes to n_signer so that standard HTTP clients (curl) and
+WebSocket clients (browsers, relay-style tools) can send JSON-RPC requests
+directly, without the custom 4-byte length-prefixed framing.
+
+## Current state
+
+n_signer supports these listener modes:
+- `unix` — abstract namespace Unix socket, 4-byte framed JSON
+- `stdio` — stdin/stdout, 4-byte framed JSON, one request per invocation
+- `qrexec` — same as stdio but with `QREXEC_REMOTE_DOMAIN` caller identity
+- `tcp:HOST:PORT` — TCP, 4-byte framed JSON
+
+All modes use the same dispatcher (`dispatcher_handle_request`) which takes a
+JSON string and returns a JSON string. The only difference between modes is the
+transport framing and caller-identity extraction.
+
+## Proposed modes
+
+### HTTP mode: `--listen http:HOST:PORT`
+
+**Protocol:** HTTP/1.1 POST with JSON body → JSON response.
+
+```
+POST / HTTP/1.1
+Content-Type: application/json
+
+{"id":"1","method":"otp_encrypt","params":["SGVsbG8=",{"encoding":"ascii"}]}
+
+HTTP/1.1 200 OK
+Content-Type: application/json
+
+{"id":"1","result":"{...}"}
+```
+
+**curl example:**
+```bash
+curl -s -X POST http://127.0.0.1:11111/ \
+  -H 'Content-Type: application/json' \
+  -d '{"id":"1","method":"get_public_key","params":[{"role":"main"}]}'
+```
+
+**Implementation:**
+- Parse the HTTP request line + headers (minimal parser — just enough for POST)
+- Read the Content-Length bytes as the JSON-RPC request
+- Call `dispatcher_handle_request()`
+- Write the HTTP response with the JSON result
+
+**Difficulty: Low.** The HTTP parser can be minimal (~100 lines). No need for
+a full HTTP server — just POST with a JSON body. No chunked encoding, no
+keep-alive, no static file serving. One request per connection (connection
+close after response), or simple keep-alive loop.
+
+**Caller identity:** `tcp:<peer-addr>` (same as TCP mode). No `QREXEC_REMOTE_DOMAIN`.
+
+**HTTPS variant:** `--listen https:HOST:PORT` wraps the HTTP listener in TLS.
+Requires `--tls-cert <path>` and `--tls-key <path>` flags. OpenSSL is already
+linked. The HTTP parser stays the same; TLS is layered underneath (accept
+connection → TLS handshake → then HTTP). See Phase 3 below.
+
+### WebSocket mode: `--listen wss:HOST:PORT` (or `ws:HOST:PORT`)
+
+**Protocol:** WebSocket with JSON text frames.
+
+```
+Client → Server: text frame with JSON-RPC request
+Server → Client: text frame with JSON-RPC response
+```
+
+**Browser example:**
+```javascript
+const ws = new WebSocket("ws://127.0.0.1:11111");
+ws.onopen = () => {
+  ws.send(JSON.stringify({id:"1", method:"get_public_key", params:[{role:"main"}]}));
+};
+ws.onmessage = (e) => {
+  console.log(JSON.parse(e.data));
+};
+```
+
+**Implementation:**
+- HTTP upgrade handshake (Sec-WebSocket-Key → Sec-WebSocket-Accept)
+- WebSocket frame parser (opcode, mask, payload length — 7/16/64 bit)
+- Text frames (opcode 0x1) carry JSON-RPC requests
+- Response as text frames (opcode 0x1, unmasked from server)
+- One JSON-RPC request per text frame; one response per request
+
+**Difficulty: Medium.** The WebSocket handshake is straightforward (SHA-1 +
+base64 of the key + magic GUID). The frame parser needs to handle:
+- 7-bit, 16-bit, and 64-bit payload lengths
+- Client-to-server masking (XOR with 4-byte mask)
+- Ping/pong frames (opcode 0x9/0xA)
+- Close frame (opcode 0x8)
+- Fragmentation (continuation frames, opcode 0x0) — can defer/skip for v1
+
+A minimal implementation is ~200-300 lines. No need for a full RFC 6455
+compliance — just enough for curl, browsers, and common WebSocket clients.
+
+**WSS (TLS) variant:** `wss:HOST:PORT` wraps the WebSocket in TLS. This
+requires linking against OpenSSL (already a dependency) and adding TLS
+handshake + certificate handling. Difficulty: Medium-High due to cert
+management. For v1, `ws:` (plaintext) is sufficient for localhost/FIPS-mesh
+use; `wss:` can be added later.
+
+**Caller identity:** `ws:<peer-addr>` or `wss:<peer-addr>`.
+
+## Security concerns
+
+### 1. Network exposure
+
+**Unix sockets** are only accessible from the same host/qube — no network
+exposure. **HTTP/WS** listeners bind to a TCP port, which is potentially
+reachable from other hosts/qubes on the network.
+
+**Mitigation:**
+- Default bind address: `127.0.0.1` (localhost only), not `[::]` (all
+  interfaces). The user must explicitly pass `--listen http:0.0.0.0:11111` to
+  expose it.
+- The existing policy/approval system is the real gate — network access alone
+  doesn't grant signing. Unknown callers get `PROMPT_EVERY_REQUEST` by default.
+
+### 2. No authentication in HTTP/WS mode
+
+The current TCP mode has no authentication either — it relies on the
+policy/approval prompt. HTTP/WS would be the same. Anyone who can reach the
+port can send requests, but they still need approval for sensitive operations.
+
+**Mitigation:**
+- The `--auth required` mode (auth envelopes) could be extended to HTTP/WS.
+  The client would include a signed auth envelope in an HTTP header
+  (e.g. `X-Nsigner-Auth: <envelope>`) or as a WebSocket subprotocol header.
+- For v1, rely on localhost binding + policy/approval prompts, same as TCP.
+
+### 3. CORS for browser access
+
+If the WebSocket listener is accessed from a browser running on a different
+origin, CORS headers are needed for the HTTP upgrade handshake.
+
+**Mitigation:**
+- Add `Access-Control-Allow-Origin: *` to the WebSocket upgrade response
+  (the policy/approval system is the real security boundary, not CORS).
+- Or restrict to same-origin only (no CORS header → browser blocks
+  cross-origin).
+
+### 4. Request size limits — MUST be raised for OTP blob encryption
+
+The current `SERVER_MAX_MSG_SIZE` is 65536 bytes (64KB). This is too small
+for OTP encryption of images or blobs:
+
+- A 48KB image → base64 in JSON param = ~64KB → hits the limit
+- A 1MB image → base64 = ~1.33MB → way over
+- OTP Padmé padding rounds up to the next power of 2, and the response
+  contains the base64-encoded ciphertext, which is even larger
+
+**This is a pre-existing limitation that affects ALL transport modes**, not
+just HTTP/WS. It should be fixed before or alongside the HTTP/WS work.
+
+**Proposed change:** raise `SERVER_MAX_MSG_SIZE` to 16MB (16777216). This
+accommodates:
+- Up to ~12MB plaintext (base64 = ~16MB in the JSON param)
+- The OTP response (base64-encoded padded ciphertext) for the same
+- The `stdin_buf[SERVER_MAX_MSG_SIZE + 1]` stack buffer in `client_main`
+  should be changed to a heap allocation to avoid a 16MB stack frame
+
+The `transport_recv_framed` function already takes a max-size parameter, so
+the change is: update the constant, change the stack buffer to malloc, and
+verify the dispatcher doesn't have other hardcoded size assumptions.
+
+**For HTTP/WS:** enforce the same `SERVER_MAX_MSG_SIZE` limit via
+`Content-Length` checking in the HTTP parser.
+
+### 5. TLS for WSS
+
+For `wss:` mode, TLS is required. This means:
+- Certificate management (self-signed for local/FIPS mesh, or CA-signed for
+  public-facing).
+- The signer would need a `--tls-cert` and `--tls-key` flag.
+- Pinning: clients should verify the cert fingerprint, not just trust the CA.
+
+**For v1:** skip WSS/TLS. Provide `ws:` (plaintext) only, suitable for
+localhost and FIPS mesh (which has its own network-level isolation). Add
+`wss:` later when there's a real public-facing use case.
+
+### 6. Connection flooding
+
+HTTP/WS listeners are susceptible to connection flooding (many open
+connections, slowloris-style attacks). The current single-threaded poll loop
+handles one connection at a time, which naturally limits flood impact but
+also limits throughput.
+
+**Mitigation:**
+- Connection timeout (close idle connections after N seconds).
+- Max connections limit.
+- For v1, the single-threaded model is fine — it's a signer, not a web server.
+
+## Implementation plan
+
+### Phase 0: Raise SERVER_MAX_MSG_SIZE (prerequisite)
+
+- [ ] Change `SERVER_MAX_MSG_SIZE` from 65536 to 16777216 (16MB) in all
+      `.c` files where it's defined (the headerless-decls pattern means it's
+      redefined in every file).
+- [ ] Change the `stdin_buf[SERVER_MAX_MSG_SIZE + 1]` stack buffer in
+      `client_main` to a heap allocation (malloc/free) to avoid a 16MB stack
+      frame.
+- [ ] Verify `transport_recv_framed` handles the larger size correctly (it
+      already takes max-size as a parameter).
+- [ ] Test with a large OTP encrypt/decrypt round-trip (e.g. 1MB plaintext).
+
+### Phase 1: HTTP listener mode
+
+- [ ] Add `NSIGNER_LISTEN_HTTP` to the listen mode enum.
+- [ ] Parse `--listen http:HOST:PORT` in the CLI flag parser.
+- [ ] Implement a minimal HTTP/1.1 parser in `src/http_listener.c`:
+  - Read request line (method, path, HTTP version)
+  - Read headers (only need Content-Length)
+  - Read body (Content-Length bytes)
+  - Reject non-POST methods with 405
+  - Reject oversized bodies with 413
+- [ ] Call `dispatcher_handle_request()` with the body, write JSON response
+  with `200 OK` + `Content-Type: application/json`.
+- [ ] Caller identity: `http:<peer-ip>:<peer-port>`.
+- [ ] Default bind: `127.0.0.1` (not `[::]`).
+- [ ] Add to interactive transport menu as option 4.
+- [ ] Test with curl.
+
+### Phase 2: WebSocket listener mode
+
+- [ ] Add `NSIGNER_LISTEN_WS` to the listen mode enum.
+- [ ] Parse `--listen ws:HOST:PORT` in the CLI flag parser.
+- [ ] Implement WebSocket handshake + frame parser in `src/ws_listener.c`:
+  - HTTP upgrade handshake (Sec-WebSocket-Key → Accept)
+  - Frame parser (opcode, mask, payload length)
+  - Text frames → JSON-RPC request → dispatcher → text frame response
+  - Ping/pong handling
+  - Close frame handling
+- [ ] Caller identity: `ws:<peer-ip>:<peer-port>`.
+- [ ] Default bind: `127.0.0.1`.
+- [ ] Add to interactive transport menu as option 5.
+- [ ] Test with a browser or `websocat`.
+
+### Phase 3: TLS mode (HTTPS + WSS)
+
+- [ ] Add `--tls-cert <path>` and `--tls-key <path>` CLI flags.
+- [ ] Add `--listen https:HOST:PORT` — HTTP listener wrapped in TLS.
+- [ ] Add `--listen wss:HOST:PORT` — WebSocket listener wrapped in TLS.
+- [ ] TLS handshake via OpenSSL (already a dependency):
+  - Load cert/key from files
+  - `SSL_CTX_new(TLS_server_method())`
+  - `SSL_CTX_use_certificate_file()` / `SSL_CTX_use_PrivateKey_file()`
+  - Per-connection: `SSL_new()` → `SSL_set_fd()` → `SSL_accept()`
+  - Replace read/write calls with `SSL_read()` / `SSL_write()`
+- [ ] Self-signed cert generation helper (or document `openssl req` command).
+- [ ] Certificate pinning guidance for clients (verify fingerprint, not just CA).
+- [ ] curl usage: `curl --cacert <cert.pem>` or `curl -k` (insecure, for testing).
+- [ ] Not strictly needed for localhost/FIPS mesh use, but good for defense in depth.
+
+## Difficulty assessment
+
+| Mode | Difficulty | New code | Dependencies | Risk |
+|---|---|---|---|---|
+| HTTP | Low | ~150 lines | None (minimal parser) | Low — simple POST/JSON |
+| WS | Medium | ~300 lines | None (minimal frame parser) | Medium — frame parsing edge cases |
+| HTTPS | Medium | ~150 + ~80 TLS | OpenSSL (already linked) | Medium — cert management |
+| WSS | Medium-High | ~300 + ~80 TLS | OpenSSL (already linked) | Higher — cert + WS edge cases |
+
+## Recommendation
+
+Start with HTTP mode (Phase 1) — it's the simplest and immediately enables
+curl access. Add WebSocket (Phase 2) if browser access is needed. Defer WSS
+(Phase 3) until there's a real public-facing use case.

plans/interactive_transport_selection.md

@@ -44,7 +44,7 @@ Each selected transport gets configured with sensible defaults:
 |---|---|---|
 | 1. Unix socket | `--listen unix` | socket name `nsigner` (or random if collision) |
 | 2. Qrexec bridge | `--listen unix --bridge-source-trusted` | socket name `nsigner`, accepts qrexec preamble |
-| 3. TCP | `--listen tcp:[::]:8080` | bind all interfaces, port 8080 |
+| 3. TCP | `--listen tcp:[::]:11111` | bind all interfaces, port 11111 |
 | 4. Qrexec one-shot | `--listen qrexec` | one request via stdin, then exit |
 
 **Choices 1 and 2 can coexist** — they're both unix listeners, just with different identity handling. Choice 2 implies choice 1's socket. If both are selected, the bridge-source-trusted flag is set on the single unix listener (it handles both local and bridge connections).
@@ -66,7 +66,7 @@ Currently `main()` creates one `server_ctx_t` and polls `server.listen_fd` + `ST
 ```text
 Connections
 listen: unix @nsigner (bridge-source-trusted)
-listen: tcp [::]:8080
+listen: tcp [::]:11111
 client: nsigner --socket-name nsigner client '<json>'
 ```
 
@@ -116,7 +116,7 @@ After confirmation, the selected listeners are started and the status display re
 ### 3.3 Transport setup from menu selection
 - [ ] Unix: `server_init` + `server_start` with `NSIGNER_LISTEN_UNIX`, socket name `nsigner`.
 - [ ] Qrexec bridge: same as unix + `server_set_bridge_source_trusted(&server, 1)`.
-- [ ] TCP: `server_init` + `server_start` with `NSIGNER_LISTEN_TCP`, target `tcp:[::]:8080`.
+- [ ] TCP: `server_init` + `server_start` with `NSIGNER_LISTEN_TCP`, target `tcp:[::]:11111`.
 - [ ] Qrexec one-shot: existing `NSIGNER_LISTEN_QREXEC` path (stdin, one request, exit).
 
 ### 3.4 TUI status display
@@ -126,7 +126,7 @@ After confirmation, the selected listeners are started and the status display re
 ### 3.5 Testing
 - [ ] Interactive: start nsigner with no `--listen`, select unix+TCP, verify both listeners work.
 - [ ] Interactive: select qrexec bridge, verify bridge connections get `qubes:<vm>` identity.
-- [ ] CLI: `--listen tcp:[::]:8080` still works (skips menu).
+- [ ] CLI: `--listen tcp:[::]:11111` still works (skips menu).
 - [ ] CLI: `--listen unix --bridge-source-trusted` still works (skips menu).
 - [ ] Non-TTY: `--mnemonic-stdin` without `--listen` defaults to unix (no menu).
 
@@ -138,6 +138,6 @@ After confirmation, the selected listeners are started and the status display re
 
 2. **Should there be a hotkey to add/remove transports at runtime?** E.g. press `t` in the TUI to bring up the transport menu again. This is a nice-to-have but adds complexity. **Decision: defer — the menu is startup-only for now.**
 
-3. **TCP port selection in the menu?** The menu could ask for a port number if TCP is selected. **Decision: default to 8080, let the user override with `--listen tcp:...` if they need a different port. Keep the menu simple.**
+3. **TCP port selection in the menu?** The menu could ask for a port number if TCP is selected. **Decision: default to 11111, let the user override with `--listen tcp:...` if they need a different port. Keep the menu simple.**
 
 4. **Socket name selection?** Same — default to `nsigner`, override with `--socket-name` if needed. **Decision: default, no prompt.**

plans/legacy_verb_aliases.md

@@ -0,0 +1,80 @@
+# Plan: Legacy Verb Aliases (Migration Path) — COMPLETED
+
+> **Status: Done.** All steps below have been executed. The legacy verb names are gone from the wire protocol, the implementation, the tests, the clients, and the documentation. `make dev` builds clean and `make test` passes (all 10 test binaries, 230+ assertions).
+
+## Context
+
+`n_signer` is being moved to a clean, unified API (see [`api.md`](../api.md)). The current implementation in [`src/dispatcher.c`](../src/dispatcher.c) still uses the legacy unprefixed verb names. This document captures the old → new mapping so the implementation can be updated in one pass. Since this is a new project, there are no external clients to migrate — the legacy names are an internal cleanup item, not a long-term compatibility surface.
+
+## Goal
+
+Rename the verbs in [`src/dispatcher.c`](../src/dispatcher.c) to match [`api.md`](../api.md), remove the legacy aliases, and delete the alias-routing logic. No backward-compatibility shim is needed.
+
+## Old → New Verb Mapping
+
+### Nostr protocol verbs (add `nostr_` prefix)
+
+| Legacy verb         | New verb                  |
+|---------------------|---------------------------|
+| `sign_event`        | `nostr_sign_event`        |
+| `mine_event`        | `nostr_mine_event`        |
+| `nip04_encrypt`     | `nostr_nip04_encrypt`     |
+| `nip04_decrypt`     | `nostr_nip04_decrypt`     |
+| `nip44_encrypt`     | `nostr_nip44_encrypt`     |
+| `nip44_decrypt`     | `nostr_nip44_decrypt`     |
+
+The role-based `get_public_key` (with `nostr_index`/`role`/`role_path` selector) becomes `nostr_get_public_key`. The algorithm-based `get_public_key` (with `algorithm` option) stays `get_public_key`.
+
+### Algorithm-based verb aliases (collapse into canonical names)
+
+| Legacy verb         | Canonical verb     | Default algorithm (when `algorithm` omitted) |
+|---------------------|--------------------|----------------------------------------------|
+| `sign_data`         | `sign`             | (from role)                                  |
+| `ssh_sign`          | `sign`             | `ed25519`                                    |
+| `verify_signature`  | `verify`           | (from role)                                  |
+| `kem_encapsulate`   | `encapsulate`      | `ml-kem-768`                                 |
+| `kem_decapsulate`   | `decapsulate`      | `ml-kem-768`                                 |
+
+After the rename, callers must always supply `algorithm` explicitly — the "default algorithm" fallbacks are removed. This makes the algorithm-based verbs uniform: every call specifies its algorithm.
+
+### OTP verb aliases (collapse into `encrypt`/`decrypt`)
+
+| Legacy verb     | Canonical verb | Required option          |
+|-----------------|----------------|--------------------------|
+| `otp_encrypt`   | `encrypt`      | `{"algorithm":"otp"}`    |
+| `otp_decrypt`   | `decrypt`      | `{"algorithm":"otp"}`    |
+
+The general `encrypt`/`decrypt` with `curve:"otp"` routing is replaced by `algorithm:"otp"`.
+
+## Implementation Steps
+
+1. **[`src/dispatcher.c`](../src/dispatcher.c)** — rename the `VERB_*` string constants:
+   - `VERB_SIGN_EVENT` → `"nostr_sign_event"`
+   - `VERB_MINE_EVENT` → `"nostr_mine_event"`
+   - `VERB_NIP04_ENCRYPT` → `"nostr_nip04_encrypt"`
+   - `VERB_NIP04_DECRYPT` → `"nostr_nip04_decrypt"`
+   - `VERB_NIP44_ENCRYPT` → `"nostr_nip44_encrypt"`
+   - `VERB_NIP44_DECRYPT` → `"nostr_nip44_decrypt"`
+   - Add `VERB_NOSTR_GET_PUBLIC_KEY` = `"nostr_get_public_key"`; split the current `get_public_key` handler into two branches based on whether `algorithm` is present (algorithm-based) or `nostr_index`/`role`/`role_path` is present (Nostr).
+
+2. **Remove alias routing** — delete [`is_algorithm_verb()`](../src/dispatcher.c:829), [`canonical_alg_verb()`](../src/dispatcher.c:846), and the alias-fallthrough logic in [`dispatcher_handle_request()`](../src/dispatcher.c:1559). The verbs `sign_data`, `ssh_sign`, `verify_signature`, `kem_encapsulate`, `kem_decapsulate`, `otp_encrypt`, `otp_decrypt` are no longer recognized.
+
+3. **Remove `curve:"otp"` routing** — the `encrypt`/`decrypt` handler no longer special-cases `curve:"otp"`; OTP is selected via `algorithm:"otp"` like every other algorithm.
+
+4. **Update tests** — [`tests/test_dispatcher.c`](../tests/test_dispatcher.c), [`tests/test_integration.c`](../tests/test_integration.c), [`tests/test_algorithm_api.c`](../tests/test_algorithm_api.c), and any other test that uses the legacy verb names. Rename all call sites to the new verbs and add `algorithm` explicitly where it was previously defaulted.
+
+5. **Update examples and clients**:
+   - [`client/demo_c99.c`](../client/demo_c99.c)
+   - [`client/demo_javascript.js`](../client/demo_javascript.js)
+   - [`client/demo_python.py`](../client/demo_python.py)
+   - [`examples/`](../examples/) — all example files using legacy verb names
+   - [`README.md`](../README.md) — the §5 summary and any inline examples
+
+6. **Update policy/preapprove** — [`src/policy.c`](../src/policy.c) and the `--preapprove` CLI parsing in [`src/main.c`](../src/main.c) should accept the new verb names. The role-based preapprove examples in [`api.md`](../api.md) §6 already use the `nostr_` prefix.
+
+## Verification
+
+- `make dev && ./build/nsigner --version` builds clean.
+- `make test` — all tests pass with the new verb names.
+- Manual smoke test over HTTP: each verb in [`api.md`](../api.md) §3 responds as documented.
+- `grep -rn "sign_event\|mine_event\|nip04_\|nip44_\|sign_data\|ssh_sign\|verify_signature\|kem_encapsulate\|kem_decapsulate\|otp_encrypt\|otp_decrypt" src/ tests/ client/ examples/` returns no matches (all legacy names gone).

plans/otp_nostr_integration.md

@@ -0,0 +1,340 @@
+# Plan: OTP-encrypted Nostr events via n_signer
+
+## Goal
+
+Store encrypted blobs on Nostr (kind `30078` replaceable parameterized events) that are
+**information-theoretically secure** — unbreakable by any computer, quantum or classical,
+forever — because they are encrypted with a one-time pad (OTP) sourced from the
+[`otp`](../otp) project.
+
+A client program sends plaintext (or a ciphertext) to `n_signer` over its existing
+JSON-RPC transport. `n_signer` performs the OTP XOR against pad material it reads from a
+USB drive, advances the per-pad offset, and returns the ciphertext (or plaintext). The
+caller then wraps the result in a Nostr `30078` event and signs/publishes it via the
+existing `sign_event` verb.
+
+Both output encodings are supported, matching the standalone `otp` tool:
+
+- **ASCII armored** (`-----BEGIN OTP MESSAGE-----` + base64): text-safe, for embedding
+  directly in Nostr event `content` (kind `30078`).
+- **Binary** (`.otp` structured header + raw encrypted bytes): for uploading to Blossom
+  servers as a blob and referencing from a Nostr event by SHA-256 hash. The caller
+  receives the binary blob base64-encoded in the JSON-RPC response and decodes it
+  before uploading.
+
+For testing, pad material can be generated from local entropy (`/dev/urandom` or
+keyboard entropy) using the `otp` tool. The eventual production target is a USB drive
+holding the pad, accessed by `n_signer` at runtime. A future microcontroller hardware
+signer that carries the pad onboard is explicitly out of scope for this plan and is
+tracked separately.
+
+## Design summary
+
+- `n_signer` gains two new verbs: `otp_encrypt` and `otp_decrypt`.
+- Pad material lives on a USB drive (file path supplied at startup). `n_signer` reads
+  only the slice it needs, XORs in `mlock`'d RAM, and writes the new offset back to the
+  pad's `.state` file on the USB drive.
+- The pad is **not** loaded whole into RAM; it is seeked-and-read per request. This
+  preserves the spirit of the zero-filesystem-footprint model (no pad material is ever
+  copied onto the host disk; the only on-disk artifact is the offset counter on the USB
+  drive itself, which is required for multi-device coordination).
+- The encrypted payload is returned in either ASCII-armored or binary `.otp` format,
+  selected per request via an `encoding` option. ASCII armor is base64-safe for JSON
+  and Nostr event `content`; binary `.otp` is for Blossom blob uploads.
+- The caller is responsible for building and publishing the `30078` event; `n_signer`
+  only does the OTP transform and (separately) signs the event when asked.
+
+```mermaid
+flowchart LR
+  Client[Client program] -->|otp_encrypt JSON-RPC| NS[n_signer]
+  NS -->|seek + read slice| USB[USB pad file .pad]
+  NS -->|read/advance offset| State[USB .state file]
+  NS -->|XOR in mlock RAM| CT[Ciphertext blob]
+  NS -->|return ascii-armored| Client
+  Client -->|wrap in 30078 event| Event[Nostr event JSON]
+  Client -->|sign_event| NS
+  NS -->|schnorr sig| Client
+  Client -->|publish| Relay[Nostr relay]
+```
+
+## Architecture decisions
+
+### 1. New verbs, not a new transport
+
+OTP operations are just new verbs on the existing dispatcher
+([`src/dispatcher.c`](src/dispatcher.c:1)). They use the same framed JSON-RPC,
+policy, approval, and enforcement machinery as `sign_event` / `nip44_encrypt`. No new
+transport is needed.
+
+### 2. Pad storage on USB, not in mnemonic RAM
+
+The OTP pad is far too large to live in `mlock`'d RAM (gigabytes) and is not
+mnemonic-derived. It lives on a USB drive mounted at a path `n_signer` is told at
+startup via a new `--otp-pad-dir <path>` flag. `n_signer` opens the pad file
+read-only, seeks to the current offset, reads exactly `chunk_size` bytes (after
+Padmé padding), XORs against the (padded) plaintext in a small `mlock`'d scratch
+buffer, and writes the advanced offset back to `<chksum>.state` on the USB drive.
+
+This is a deliberate, narrow exception to the "zero filesystem footprint" rule: the
+only filesystem artifact `n_signer` touches is the offset counter on the USB drive
+itself, which is mandatory for pad-reuse avoidance across devices. No pad bytes and
+no plaintext ever touch the host disk.
+
+### 2a. Qubes OS USB access strategy
+
+On Qubes, the signer qube must have sole access to the pad-bearing USB drive. The
+chosen strategy is **PCI USB controller passthrough** (Option A): an entire USB
+controller is assigned to the signer qube via `qvm-pci attach`, so dom0, `sys-usb`,
+and every other qube are blind to the pad device. The drive appears as a normal
+`/dev/sd*` inside the signer qube.
+
+Fallback if no spare controller is available: **`qvm-block attach` from `sys-usb`**
+(Option B), accepting that `sys-usb` briefly enumerates the device and block I/O
+transits dom0's blkback (a traffic-analysis concern, not a plaintext-leak concern
+since pad bytes stay encrypted-on-disk).
+
+Code-level guard (Option D): `n_signer` refuses to open `--otp-pad-dir` unless the
+underlying device is a directly-owned PCI device (`/dev/sd*` from a passthrough
+controller) when running under Qubes; blkback devices (`/dev/xvdi`) are rejected
+unless `--otp-allow-blkback` is explicitly passed. This makes "sole access" a
+code-level invariant, not just an operator convention.
+
+Offset writes use atomic write-temp-then-rename so a crash mid-write cannot corrupt
+the `.state` file. The offset is advanced **only after** the XOR succeeds and the
+ciphertext is handed back to the caller.
+
+### 3. Reuse the `otp` project's file formats and padding
+
+- Pad file format: `<chksum>.pad` raw random bytes, with a 32-byte header reserved
+  (matches [`../otp/src/pads.c`](../otp/src/pads.c:1) `offset=32` initial reservation).
+- State file format: `<chksum>.state` containing `offset=<n>\n` (matches
+  [`../otp/src/pads.c:284`](../otp/src/pads.c:284) `read_state_offset`).
+- ASCII armor format: `-----BEGIN OTP MESSAGE-----` with `Pad-ChkSum` and
+  `Pad-Offset` headers (matches [`../otp/src/crypto.c`](../otp/src/crypto.c:1)
+  `parse_ascii_message` / `generate_ascii_armor`).
+- Padding: exponential bucketing + ISO/IEC 9797-1 Method 2 (Padmé) from
+  [`../otp/src/padding.c`](../otp/src/padding.c:1).
+
+This means pads generated by the standalone `otp` CLI are bit-compatible with pads
+consumed by `n_signer`, and ciphertexts produced by either tool are interchangeable.
+
+### 4. Code sharing strategy
+
+Rather than vendoring a copy of the `otp` source into `n_signer`, extract the
+format-critical functions into a small shared static library `libotppad` that both
+projects link against. Candidates to extract:
+
+- `universal_xor_operation` ([`../otp/src/crypto.c:35`](../otp/src/crypto.c:35))
+- `parse_ascii_message` / `generate_ascii_armor`
+- `calculate_chunk_size` / `apply_padme_padding` / `remove_padme_padding`
+  ([`../otp/src/padding.c`](../otp/src/padding.c:1))
+- `read_state_offset` / `write_state_offset`
+  ([`../otp/src/pads.c:284`](../otp/src/pads.c:284))
+- `calculate_checksum` (pad identification)
+
+`n_signer` then only needs to implement: USB pad directory config, the two new
+dispatcher verbs, the seek-read-XOR-write-offset loop, and approval/policy wiring.
+
+### 5. Nostr event shape (kind 30078)
+
+The caller builds the event; `n_signer` does not. Two payload patterns:
+
+**A. ASCII armor in event content** (text-safe, self-contained):
+
+```json
+{
+  "kind": 30078,
+  "content": "-----BEGIN OTP MESSAGE-----\nVersion: v0.3.53\nPad-ChkSum: <64hex>\nPad-Offset: <n>\n\n<base64>\n-----END OTP MESSAGE-----",
+  "tags": [
+    ["d", "<caller-chosen-d-tag>"],
+    ["otp-pad", "<16-char chksum prefix>"],
+    ["otp-version", "v0.3.53"],
+    ["otp-encoding", "ascii"]
+  ],
+  ...
+}
+```
+
+**B. Binary `.otp` uploaded to Blossom, referenced by hash** (for binaries/large blobs):
+
+```json
+{
+  "kind": 30078,
+  "content": "",
+  "tags": [
+    ["d", "<caller-chosen-d-tag>"],
+    ["otp-pad", "<16-char chksum prefix>"],
+    ["otp-version", "v0.3.53"],
+    ["otp-encoding", "binary"],
+    ["blob", "<sha256-hex>", "<mimetype>", "<size-bytes>"],
+    ["url", "<blossom-url>"]
+  ],
+  ...
+}
+```
+
+In both cases the `Pad-Offset` (in the ASCII armor header, or in the binary `.otp`
+file header) is what a decrypting device uses to seek into its copy of the same pad.
+The `otp-pad` tag lets a reader find the right pad without parsing the payload first.
+The `otp-encoding` tag tells the reader whether to look in `content` or follow the
+`blob`/`url` tags to Blossom.
+
+### 6. Multi-device offset coordination (deferred)
+
+Out of scope for v1. The `.state` file on the device's USB drive is the local source
+of truth for how far that device has consumed the pad, and the `Pad-Offset` header
+in each ciphertext's ASCII armor / binary header records which slice was used. That
+is sufficient for single-device operation.
+
+If multi-device pad sharing is added later (two devices holding copies of the same
+`.pad`), a dedicated signed coordination event would be needed so devices never
+reuse a slice. That event does not have to be kind `30078` and is not designed here.
+Note: kind `30078` is a Nostr application-data convention, not part of the OTP spec —
+the `otp` project has no Nostr code today.
+
+## Phased implementation
+
+### Phase 0 — Test pad on the USB drive ✅ Done
+
+- [x] Created `pads/` directory on the mounted USB drive.
+- [x] Generated a 1 MB test pad from `/dev/urandom` with a 32-byte reserved header,
+      using [`tools/make_test_pad.c`](tools/make_test_pad.c:1).
+- [x] Computed the pad's 256-bit XOR checksum (matching the `otp` project's
+      [`../otp/src/crypto.c:242`](../otp/src/crypto.c:242) `calculate_checksum`
+      algorithm) and named the pad file by that checksum.
+- [x] Wrote the initial `.state` file (`offset=32\n`).
+- [x] Verified the checksum matches the filename via an independent re-computation.
+
+**Actual test pad on this qube:**
+
+| Field | Value |
+|---|---|
+| USB drive | SanDisk 3.2 Gen1, 466 GB, `/dev/sda1` |
+| Mount point | `/media/user/Music` (FAT32, label "Music") |
+| Pad directory | `/media/user/Music/pads` |
+| Pad file | `333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e.pad` |
+| State file | `333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e.state` |
+| Size | 1,048,576 bytes (1 MB) |
+| Chksum prefix | `333e9902db839d9d` |
+| Initial offset | 32 (header reserved) |
+
+Note: the drive is currently mounted at `/media/user/Music` (its FAT32 label is
+"Music"), not at `/media/user/USBDISK`. For `n_signer` testing, pass
+`--otp-pad-dir /media/user/Music/pads`. This pad is for local-entropy testing only;
+production pads will be generated with the `otp` CLI (keyboard/TRNG entropy) or a
+future hardware signer.
+
+### Phase 1 — Shared `libotppad` extraction
+
+- [ ] Create `libotppad/` directory with the format-critical functions extracted from
+      [`../otp/src/crypto.c`](../otp/src/crypto.c:1), [`../otp/src/padding.c`](../otp/src/padding.c:1),
+      and [`../otp/src/pads.c`](../otp/src/pads.c:1).
+- [ ] Add a `libotppad.h` public header declaring: `universal_xor_operation`,
+      `parse_ascii_message`, `generate_ascii_armor`, `calculate_chunk_size`,
+      `apply_padme_padding`, `remove_padme_padding`, `read_state_offset`,
+      `write_state_offset`, `calculate_checksum`.
+- [ ] Refactor the `otp` project to link against `libotppad` instead of its own copies.
+- [ ] Add unit tests for `libotppad` (round-trip encrypt/decrypt, padding edge cases,
+      state file read/write).
+
+### Phase 2 — `n_signer` USB pad directory support
+
+- [ ] Add `--otp-pad-dir <path>` CLI flag to [`src/main.c`](src/main.c:1); store the
+      path in a new `otp_pad_state_t` alongside the existing mnemonic/role state.
+- [ ] Add a `--otp-pad <chksum-or-prefix>` flag (or interactive selector) to pick
+      **the single pad** that is active for this session. One pad per session — the
+      pad is bound at startup and cannot be switched without restarting `n_signer`.
+- [ ] Implement `otp_pad_open(chksum)` / `otp_pad_read_slice(offset, len)` /
+      `otp_pad_advance_offset(delta)` helpers in a new `src/otp_pad.c`.
+- [ ] Validate the pad's checksum matches the requested chksum before first use.
+- [ ] Refuse to operate if the pad directory is on the same filesystem as `/` (require
+      it to be a removable mount — best-effort check via `statvfs`).
+
+### Phase 3 — `otp_encrypt` / `otp_decrypt` verbs
+
+- [ ] Add `VERB_OTP_ENCRYPT "otp_encrypt"` and `VERB_OTP_DECRYPT "otp_decrypt"` to
+      [`src/dispatcher.c`](src/dispatcher.c:1).
+- [ ] Request shapes (plaintext is base64 in the JSON param for both text and
+      binary; the pad is the one bound at startup, so no `pad` field is needed):
+  ```json
+  { "id": "1", "method": "otp_encrypt",
+    "params": [ "<plaintext-base64>", { "encoding": "ascii|binary" } ] }
+  ```
+  ```json
+  { "id": "2", "method": "otp_decrypt",
+    "params": [ "<ciphertext-ascii-armor-or-base64-otp-blob>", { "encoding": "ascii|binary" } ] }
+  ```
+- [ ] `otp_encrypt` flow: padmé-pad plaintext → seek to offset → read slice → XOR in
+      `mlock`'d scratch → advance offset → return ciphertext in requested encoding
+      (`ascii` → ASCII-armored string, `binary` → base64-encoded `.otp` blob in the
+      JSON result).
+- [ ] `otp_decrypt` flow: accept either ASCII armor or base64-encoded binary `.otp`
+      blob → parse header → seek to `Pad-Offset` → read slice → XOR in `mlock`'d
+      scratch → strip padding → return plaintext (in requested encoding).
+- [ ] Add an `encoding` option to both verbs: `"encoding": "ascii"` (default) or
+      `"encoding": "binary"`. For `otp_encrypt`, controls output format. For
+      `otp_decrypt`, tells the signer what format the input is in (auto-detection by
+      magic bytes `OTP\0` is a fallback).
+- [ ] Wire both verbs into the policy/enforcement table
+      ([`src/policy.c`](src/policy.c:1), [`src/enforcement.c`](src/enforcement.c:1))
+      with **per-session grant** approval: the first `otp_encrypt` / `otp_decrypt`
+      call for the session prompts the user; once granted, subsequent calls on the
+      same pad in the same session do not re-prompt. This matches the `[a] always
+      allow this session` hotkey behavior already in [`README.md`](README.md:1).
+- [ ] Add approval-prompt display fields: pad chksum prefix, offset before/after,
+      plaintext length bucket.
+
+### Phase 4 — Local-entropy test path
+
+- [ ] Document the test workflow: generate a small pad with the `otp` CLI
+      (`./otp generate 1MB`) into a directory, point `n_signer` at it with
+      `--otp-pad-dir`, run `otp_encrypt` round-trips from a client.
+- [ ] Add an integration test in [`tests/test_integration.c`](tests/test_integration.c:1)
+      that: starts `n_signer` with a temp pad dir, calls `otp_encrypt` then
+      `otp_decrypt`, asserts round-trip equality, and asserts the offset advanced by
+      the padded chunk size.
+- [ ] Add a test that confirms a ciphertext produced by `n_signer` can be decrypted by
+      the standalone `otp` CLI (cross-compatibility).
+
+### Phase 5 — Nostr 30078 client example
+
+- [ ] Add `examples/otp_nostr_30078.c` showing: call `otp_encrypt` → build a kind 30078
+      event with the ASCII armor as `content` → call `sign_event` → print the signed
+      event for publishing.
+- [ ] Add a matching `examples/otp_nostr_30078_decrypt.c` showing: fetch a 30078 event
+      → call `otp_decrypt` with its `content` → print recovered plaintext.
+- [ ] Document the workflow in [`documents/`](documents/) and link from
+      [`README.md`](README.md:1).
+
+### Phase 6 (deferred) — USB-bound pad hardening
+
+- [ ] Detect removable-mount requirement more strictly (udev properties).
+- [ ] Optional: read-only mount enforcement, pad integrity re-check on each request.
+- [ ] Optional: per-pad `mlock`'d offset cache so a crash mid-request does not corrupt
+      the `.state` file (write-offset-after-success-only is already the plan).
+
+### Phase 7 (explicitly deferred) — Microcontroller hardware signer with onboard pad
+
+Tracked separately. When it lands, the `--otp-pad-dir` path is replaced by a transport
+call (serial/WebUSB) to a pad-serving firmware, and the verbs stay identical.
+
+## Decisions
+
+1. **Plaintext encoding in `otp_encrypt` params.** Accept base64 in the JSON param
+   for both text and binary plaintext; the signer decodes it. Output encoding is the
+   `ascii` vs `binary` option described above.
+2. **One pad per session.** The pad is bound at `n_signer` startup via
+   `--otp-pad-dir` + `--otp-pad` and cannot be switched without restarting the
+   signer. Simpler and safer for v1.
+3. **No pad-heartbeat event in v1.** The `.state` file on the USB drive is the local
+   source of truth; the `Pad-Offset` header in each ciphertext records the slice
+   used. Multi-device pad sharing and any coordination event are deferred. (Kind
+   `30078` is a Nostr application-data convention, not part of the OTP spec.)
+4. **Per-session grant approval.** The first `otp_encrypt` / `otp_decrypt` call in a
+   session prompts the user; once granted, subsequent calls on the same pad do not
+   re-prompt. Matches the existing `[a] always allow this session` behavior.
+5. **Qubes USB strategy.** PCI USB controller passthrough (Option A) is the target;
+   `qvm-block` from `sys-usb` (Option B) is the fallback. For development/testing,
+   the USB drive is already accessible in this qube at `/media/user/Music` (see
+   Phase 0). Code-level guard (Option D) rejects blkback devices unless
+   `--otp-allow-blkback` is passed.

plans/ssh_agent_proxy.md

@@ -0,0 +1,263 @@
+# Plan: SSH Agent Proxy Bridge for n_signer
+
+## 1. Goal
+
+Allow untrusted Qubes qubes to SSH into remote servers using an ed25519 private key held safely in n_signer, without the private key ever leaving the signer qube.
+
+The untrusted qube runs a small proxy program that implements the OpenSSH `ssh-agent` protocol. OpenSSH talks to the proxy as if it were a normal `ssh-agent`. The proxy forwards signing requests to n_signer via qrexec. The private key never touches the untrusted qube's memory.
+
+## 2. Architecture
+
+```mermaid
+graph LR
+    SSH[ssh client in untrusted qube] -->|SSH_AUTH_SOCK| PROXY[nsigner-ssh-agent proxy]
+    PROXY -->|qrexec qubes.NsignerRpc| SIGNER[n_signer in nostr_signer qube]
+    SIGNER -->|derives ed25519 key from mnemonic| KEY[ed25519 private key in mlock'd RAM]
+    SSH -->|SSH protocol| SERVER[remote SSH server]
+```
+
+**Flow:**
+1. User in untrusted qube runs `ssh user@server`
+2. OpenSSH connects to the proxy via `SSH_AUTH_SOCK`
+3. OpenSSH sends `SSH_AGENTC_REQUEST_IDENTITIES` — proxy fetches the ed25519 public key from n_signer and returns it
+4. OpenSSH sends the public key to the remote server as part of `SSH_MSG_USERAUTH_REQUEST`
+5. The server sends back a challenge (the data to sign)
+6. OpenSSH sends `SSH_AGENTC_SIGN_REQUEST` with the challenge data to the proxy
+7. The proxy forwards the data to n_signer via qrexec: `{"method":"sign","params":["<hex>","algorithm":"ed25519","index":0]}`
+8. n_signer signs the data with the ed25519 private key and returns the signature
+9. The proxy returns the signature to OpenSSH
+10. OpenSSH sends the signed authentication response to the server
+
+**Key security property:** The private key exists only in n_signer's mlock'd memory in the `nostr_signer` qube. The untrusted qube never sees it. The proxy only ever handles public keys and signing requests/responses.
+
+## 3. The ssh-agent protocol
+
+OpenSSH's agent protocol is defined in `draft-miller-ssh-agent` (PROTOCOL.agent in the OpenSSH source). It uses a Unix socket with a simple message framing:
+
+**Message format:**
+```
+uint32    message_length
+byte      message_type
+byte[]    message_data
+```
+
+**Messages the proxy must handle:**
+
+### SSH_AGENTC_REQUEST_IDENTITIES (11)
+Request the list of keys the agent holds.
+
+**Response: SSH_AGENT_IDENTITIES_ANSWER (12)**
+```
+uint32    num_keys
+string    key_blob_1       (public key in SSH wire format)
+string    key_comment_1    (human-readable comment)
+string    key_blob_2
+string    key_comment_2
+...
+```
+
+The proxy returns one key: the ed25519 public key from n_signer, formatted as an SSH ed25519 public key blob.
+
+**SSH ed25519 public key blob format:**
+```
+string    "ssh-ed25519"
+string    <32-byte public key>
+```
+
+### SSH_AGENTC_SIGN_REQUEST (13)
+```
+string    key_blob         (the public key to sign with)
+string    data             (the data to sign)
+uint32    flags            (SSH_AGENT_SIGN_FLAG_* — currently 0 or SSH_AGENT_FLAG_RSA_SHA2_256/512 for RSA only)
+```
+
+**Response: SSH_AGENT_SIGN_RESPONSE (14)**
+```
+string    signature_blob
+```
+
+**SSH ed25519 signature blob format:**
+```
+string    "ssh-ed25519"
+string    <64-byte signature>
+```
+
+### Other messages
+- `SSH_AGENTC_REMOVE_ALL_IDENTITIES` (11) — return `SSH_AGENT_SUCCESS`
+- `SSH_AGENTC_REMOVE_IDENTITY` (18) — return `SSH_AGENT_SUCCESS`
+- `SSH_AGENTC_LOCK` / `SSH_AGENTC_UNLOCK` (22/23) — return `SSH_AGENT_SUCCESS`
+- `SSH_AGENTC_ADD_IDENTITY` (17) — return `SSH_AGENT_FAILURE` (we don't allow adding keys)
+- Any unknown message — return `SSH_AGENT_FAILURE` (5)
+
+## 4. Implementation
+
+### 4.1 New program: `nsigner-ssh-agent`
+
+A small C program (~400-500 lines) that:
+
+1. Creates a Unix socket at a configurable path (default: `$XDG_RUNTIME_DIR/nsigner-ssh-agent.sock`)
+2. Listens for connections from OpenSSH
+3. On `SSH_AGENTC_REQUEST_IDENTITIES`:
+   - Calls n_signer via qrexec to get the ed25519 public key: `{"method":"get_public_key","params":[{"algorithm":"ed25519","index":0}]}`
+   - Parses the structured response to extract the 32-byte public key
+   - Formats it as an SSH ed25519 key blob
+   - Returns `SSH_AGENT_IDENTITIES_ANSWER` with one key
+4. On `SSH_AGENTC_SIGN_REQUEST`:
+   - Extracts the data to sign from the request
+   - Calls n_signer via qrexec: `{"method":"sign","params":["<data_hex>",{"algorithm":"ed25519","index":0}]}`
+   - Parses the response to extract the 64-byte signature
+   - Formats it as an SSH ed25519 signature blob
+   - Returns `SSH_AGENT_SIGN_RESPONSE`
+5. On other messages: returns appropriate responses (see §3)
+
+**Key caching:** The proxy caches the public key after the first `REQUEST_IDENTITIES` call (it doesn't change during a session). The private key is never cached — each sign request goes to n_signer.
+
+**Multiple keys:** The proxy can support multiple ed25519 keys by using different `index` values. Configuration via command-line args or environment variables:
+```bash
+nsigner-ssh-agent --index 0 --index 1 --index 2
+```
+Each index produces a different ed25519 key, all derived from the same mnemonic.
+
+### 4.2 qrexec communication
+
+The proxy communicates with n_signer via `qrexec-client-vm nostr_signer qubes.NsignerRpc`, using the same 4-byte big-endian length framing as the existing qrexec examples.
+
+Each qrexec call is a one-shot: spawn `qrexec-client-vm`, send one framed request, receive one framed response, exit. This matches the existing qrexec protocol.
+
+### 4.3 Configuration
+
+**In the untrusted qube:**
+```bash
+# Start the proxy in the background
+nsigner-ssh-agent --socket $XDG_RUNTIME_DIR/nsigner-ssh-agent.sock &
+export SSH_AUTH_SOCK=$XDG_RUNTIME_DIR/nsigner-ssh-agent.sock
+export SSH_AUTH_SIGNER_QUBE=nostr_signer
+
+# Now use ssh normally
+ssh user@server
+```
+
+**In the nostr_signer qube:**
+- n_signer must be running with the mnemonic loaded
+- The `qubes.NsignerRpc` service must be installed
+- The qrexec policy must allow the untrusted qube to call `qubes.NsignerRpc`
+
+**Qubes policy (`packaging/qubes/policy.d/40-nsigner.policy`):**
+```
+nsigner.NsignerRpc +untrusted-qube nostr_signer allow
+```
+
+Or with the deny-by-default model from n_signer's policy:
+```
+nsigner.NsignerRpc +untrusted-qube nostr_signer ask
+```
+The `ask` policy shows a Qubes dom0 prompt each time the untrusted qube tries to sign, giving the user a chance to approve/deny.
+
+### 4.4 n_signer policy
+
+Use n_signer's `--preapprove` to pre-approve the untrusted qube for ed25519 signing:
+```bash
+nsigner --preapprove caller=qubes:untrusted-qube,algorithm=ed25519,index=0,verb=sign,get_public_key
+```
+
+Or use the deny-by-default prompt model — each sign request shows a prompt in the signer qube's TUI:
+```
+Caller: qubes:untrusted-qube
+Action: sign with ed25519
+Key:    index 0 (key_id: 1fd9c73a93189484)
+[a] approve  [d] deny
+```
+
+### 4.5 File structure
+
+```
+src/nsigner_ssh_agent.c     — the proxy program
+packaging/qubes/
+    install-ssh-agent.sh    — install the proxy in an AppVM
+    ssh-agent.desktop       — autostart the proxy on qube boot
+```
+
+### 4.6 Build
+
+The proxy is a separate binary, not part of the main nsigner binary. It links against:
+- cJSON (for JSON-RPC parsing)
+- libnostr_core (for the qrexec transport framing)
+
+Makefile target:
+```makefile
+$(BUILD_DIR)/nsigner-ssh-agent: src/nsigner_ssh_agent.c
+    $(CC) $(CFLAGS) src/nsigner_ssh_agent.c -o $(BUILD_DIR)/nsigner-ssh-agent $(LDFLAGS)
+```
+
+## 5. Security considerations
+
+### 5.1 The untrusted qube sees the public key
+
+The ed25519 public key is sent to the untrusted qube. This is fine — public keys are not secret. The untrusted qube could share the public key with anyone, but that doesn't compromise the private key.
+
+### 5.2 The untrusted qube controls what is signed
+
+The untrusted qube constructs the SSH authentication message and sends it to the proxy for signing. The proxy forwards it to n_signer, which signs it without inspecting the content.
+
+**Risk:** A compromised untrusted qube could ask n_signer to sign arbitrary data, not just SSH authentication messages. The ed25519 signature could be used for purposes other than SSH.
+
+**Mitigation:** This is the same trust model as any ssh-agent. A compromised process with access to `SSH_AUTH_SOCK` can sign arbitrary data. The n_signer policy model (deny-by-default with per-request approval) provides an additional layer: the user can see each sign request at the signer's TUI and approve/deny it.
+
+### 5.3 The proxy holds no secrets
+
+The proxy process in the untrusted qube holds no private key material. It only has:
+- The Unix socket path
+- The qrexec target qube name
+- The cached public key (non-secret)
+- The ed25519 index to use
+
+If the proxy process is compromised, the attacker gains the ability to forward sign requests to n_signer — but n_signer's policy still gates each request.
+
+### 5.4 Qubes qrexec authentication
+
+The qrexec framework authenticates the source qube. n_signer sees the caller as `qubes:<source-vm>`. This means:
+- The signer knows which qube is requesting the signature
+- The Qubes dom0 policy controls which qubes can call the service
+- The n_signer policy can approve specific qubes for specific algorithms/verbs
+
+### 5.5 No private key on disk
+
+The ed25519 private key is never written to disk. It's derived from the mnemonic in n_signer's mlock'd RAM on each startup. The proxy doesn't have the mnemonic. The untrusted qube doesn't have the mnemonic. Only the `nostr_signer` qube has the mnemonic (entered at startup, never persisted).
+
+## 6. What is explicitly out of scope
+
+1. **RSA key support** — the proxy only supports ed25519. RSA SSH keys require different signing (PKCS#1 v1.5 or PSS) and different key derivation. ed25519 is the modern default.
+2. **SSH certificate support** — OpenSSH certificates (ssh-ed25519-cert-v01@openssh.com) are not supported. These require a CA key to sign the certificate, which is a separate workflow.
+3. **Agent forwarding** — `ssh -A` (forwarding the agent to a remote host) is not supported. The proxy only accepts local Unix socket connections.
+4. **Multiple signer qubes** — the proxy talks to one n_signer instance. Multiple signers would require multiple proxy instances.
+5. **Hybrid PQ SSH keys** — OpenSSH doesn't support PQ signing keys yet. When it does, the proxy can be extended to use ML-DSA-65 via n_signer's `sign` verb with `algorithm=ml-dsa-65`.
+
+## 7. Implementation phases
+
+### Phase 1: Core proxy
+- Implement `nsigner-ssh-agent.c` with ssh-agent protocol handling
+- Implement qrexec communication with n_signer
+- Support `SSH_AGENTC_REQUEST_IDENTITIES` and `SSH_AGENTC_SIGN_REQUEST`
+- Test with a real SSH connection
+
+### Phase 2: Qubes integration
+- Install script for AppVMs
+- Autostart on qube boot
+- Qubes policy documentation
+- n_signer `--preapprove` documentation
+
+### Phase 3: Hardening
+- Connection rate limiting (prevent sign-request flooding)
+- Optional: inspect the sign request to verify it looks like an SSH auth message
+- Optional: support multiple ed25519 indices (multiple SSH identities)
+- Optional: support `SSH_AGENTC_REQUEST_EXTENSION` for OpenSSH extensions
+
+## 8. Open questions
+
+1. **Should the proxy inspect the sign request data?** The proxy could check that the data being signed looks like an SSH authentication message (starts with the session ID, has the right message type). This would prevent the untrusted qube from using the signer for non-SSH signing. However, it's fragile (SSH protocol may change) and doesn't match how normal ssh-agents work. Default: no inspection, rely on n_signer's policy.
+
+2. **Should the proxy support `ssh-add -l`?** `ssh-add -l` lists the keys the agent holds, which maps to `SSH_AGENTC_REQUEST_IDENTITIES`. Yes, this is already supported by the protocol handling.
+
+3. **Should the proxy cache the public key across connections?** Yes — the public key doesn't change during a session. Cache it after the first `REQUEST_IDENTITIES` call. Clear the cache on `SIGHUP` or when the qrexec call fails.
+
+4. **Should we support `sk-ssh-ed25519@openssh.com` (security key) key type?** This is the YubiKey key type. It adds a "flags" byte to the signature (e.g., "require user presence"). Not needed for n_signer, but could be useful for compatibility with systems that expect security key signatures. Default: no, use standard `ssh-ed25519`.

plans/teensy41_signer_port.md

@@ -0,0 +1,248 @@
+# Plan: Port n_signer to Teensy 4.1 with SDXC 1 TB exFAT OTP Pad
+
+## Goal
+
+Port the n_signer hardware signer to the **Teensy 4.1** (NXP i.MX RT1062,
+Cortex-M7 @ 600 MHz), using its built-in SD slot to hold a **1 TB SDXC exFAT
+one-time-pad file**. The Teensy 4.1 is the high-capacity-OTP target; the CYD
+(classic ESP32) remains the cheap/low-power option with the mnemonic-derived
+stream pad.
+
+The on-the-wire protocol is identical to the host and the CYD/feather firmware
+([`README.md`](../README.md) §4 — the algorithm-based API). The auth envelope,
+verb set, enforcement matrix, `key_id` convention, and structured-result JSON
+are all unchanged.
+
+## Why the Teensy 4.1
+
+| Concern | Teensy 4.1 | CYD (ESP32) |
+|---|---|---|
+| MCU | 600 MHz Cortex-M7 | 240 MHz Xtensa LX6 |
+| SRAM | 1 MB + 16 MB PSRAM (on-board) | 512 KB, no PSRAM |
+| SD slot | **4-bit SDMMC, exFAT via SdFat, up to 2 TB** | 1-bit SDSPI, FAT32, up to 32 GB |
+| SD speed | ~20-40 MB/s | ~2 MB/s |
+| USB | Hi-Speed (480 Mbps) device + host | CH340 UART only |
+| WiFi | **None** | Yes (unused) |
+| PQ crypto | ~1-2 s SLH-DSA-128s | 5-30 s SLH-DSA-128s |
+| Display | Add SPI ILI9341 (same panel as CYD) | Built-in 2.8" ILI9341 + touch |
+
+The decisive factor is the **SD slot**: PJRC's [SdFat](https://github.com/greiman/SdFat)
+library has native exFAT support, so a 1 TB SDXC card (which ships formatted
+exFAT) mounts and reads/writes directly — no reformatting, no exFAT driver
+work. The 4-bit SDMMC bus is fast enough (~20-40 MB/s) for pad reads with
+arbitrary seeks.
+
+## Hardware
+
+### Board
+- **Teensy 4.1** (PJRC) — $27. Has 8 MB flash, 16 MB external QSPI, 16 MB PSRAM
+  (soldered), 1 MB internal SRAM, native USB Hi-Speed, built-in SD slot, 10/100
+  Ethernet PHY, no WiFi/BT.
+
+### Display + touch (add-on)
+- **4.0" ST7796S 480×320 with XPT2046 resistive touch** (Hosyond or equivalent,
+  ~$12-15). Specs: 4-wire SPI, RGB 65K, 3.3V~5V (works at Teensy's 3.3V logic),
+  XPT2046 resistive touch, includes touch pen + SD card slot on the module.
+  SPI wiring to the Teensy 4.1:
+  - TFT: MOSI=pin 11, SCK=pin 13, MISO=pin 12, CS=pin 10, DC=pin 9,
+    RESET=pin 8, BL=pin 22 (PWM via analogWrite)
+  - Touch (XPT2046, shared SPI bus): T_CS=pin 7, T_IRQ=pin 6,
+    T_CLK=pin 13, T_MOSI=pin 11, T_MISO=pin 12
+  - Power: VCC=3.3V, GND=GND
+- The ST7796S controller needs a different init sequence than the CYD's
+  ILI9341, and the resolution is 480×320 (not 320×240). The XPT2046 touch
+  driver ports from [`firmware/cyd_esp32_2432s028/main/touch.c`](../firmware/cyd_esp32_2432s028/main/touch.c)
+  with new resolution constants.
+- The module's on-board SD card slot is a bonus (backup pad / offset file),
+  but the 1 TB pad uses the Teensy's built-in SD slot (4-bit SDMMC, faster).
+
+### SD card
+- **1 TB microSDXC** (exFAT, ~$60-80) in the Teensy's built-in slot.
+- The pad file (`/pad.bin`) + offset file (`/pad.offset`) live on this card.
+
+### USB transport
+- The Teensy's native USB port (device mode) exposes a **CDC-ACM serial** +
+  optional **WebUSB vendor** interface (TinyUSB composite), same framing as the
+  feather/CYD (4-byte big-endian length prefix + JSON-RPC payload).
+- The host sees `/dev/ttyACM0` (Linux) or `COMx` (Windows).
+
+## Target directory layout
+
+```
+firmware/teensy41/
+├── README.md                  (created)
+├── teensy41_signer.ino        (Arduino entry, or main.cpp for PlatformIO)
+├── src/
+│   ├── main.cpp               (app loop: UI → transport → dispatch)
+│   ├── dispatch.cpp           (verb dispatch — ported from cyd main.c handle_request)
+│   ├── dispatch.h
+│   ├── key_derivation.cpp     (BIP-39 → seed → secp256k1/ed25519/x25519/PQ keys)
+│   ├── key_derivation.h
+│   ├── pq_crypto.cpp          (PQClean wrappers: ml-dsa-65, slh-dsa-128s, ml-kem-768)
+│   ├── pq_crypto.h
+│   ├── otp_pad_sd.cpp         (SDXC exFAT pad: mount, read, offset persistence)
+│   ├── otp_pad_sd.h
+│   ├── transport.cpp          (USB CDC + length-prefix framing)
+│   ├── transport.h
+│   ├── display.cpp            (ILI9341 driver — ported from cyd ili9341.c)
+│   ├── display.h
+│   ├── touch.cpp              (XPT2046 driver — ported from cyd touch.c)
+│   ├── touch.h
+│   ├── ui.cpp                 (LVGL or hand-rolled UI — ported from cyd ui.c)
+│   ├── ui.h
+│   ├── secure_mem.cpp         (zeroize helpers)
+│   ├── secure_mem.h
+│   ├── bech32.cpp             (npub encoding)
+│   ├── bech32.h
+│   ├── mnemonic.cpp           (BIP-39 wordlist + validation)
+│   ├── mnemonic.h
+│   └── mnemonic_wordlist.h
+├── lib/
+│   ├── secp256k1/             (libsecp256k1, built for ARM Cortex-M7)
+│   ├── pqclean/               (PQClean ML-DSA-65, SLH-DSA-128s, ML-KEM-768)
+│   ├── nostr_core_lib/        (symlink/copy of resources/nostr_core_lib)
+│   └── SdFat/                 (PJRC SdFat with exFAT — via Arduino Library Manager)
+└── platformio.ini             (or Arduino project config)
+```
+
+## Architecture
+
+```mermaid
+flowchart TD
+    USB[Host USB CDC] --> Frame[transport.cpp<br/>length-prefix framing]
+    Frame --> Auth[auth envelope verify<br/>secp256k1 schnorr]
+    Auth -->|ok| Disp[dispatch.cpp<br/>handle_request]
+    Auth -->|fail| Err[auth error]
+    Disp -->|nostr_*| NIP[Nostr verbs<br/>secp256k1 NIP-06]
+    Disp -->|alg verb| Alg[Algorithm verbs<br/>algorithm + index]
+    Alg -->|otp| OTP[otp_pad_sd.cpp<br/>SDXC exFAT pad]
+    Alg -->|secp256k1/ed25519/x25519/PQ| KD[key_derivation.cpp]
+    OTP --> SD[(1 TB SDXC<br/>exFAT<br/>/pad.bin + /pad.offset)]
+    KD --> UI[ui.cpp<br/>approval prompt<br/>ILI9341 + XPT2046]
+    UI -->|approve| Exec[execute verb]
+    Exec --> Resp[structured JSON result]
+    Resp --> Frame
+```
+
+## Implementation phases
+
+### Phase 1: Board bring-up (display + touch + SD)
+
+1. **Toolchain:** Arduino CLI + Teensyduino (simplest), or PlatformIO with the
+   `teensy` platform. Verify `Blink` + `HelloSerial` compile and flash.
+2. **ILI9341 display:** port [`firmware/cyd_esp32_2432s028/main/ili9341.c`](../firmware/cyd_esp32_2432s028/main/ili9341.c)
+   to Teensy GPIO + SPI (use `SPI.beginTransaction` for 40 MHz HSPI). Exit
+   criterion: fill screen + draw text.
+3. **XPT2046 touch:** port [`firmware/cyd_esp32_2432s028/main/touch.c`](../firmware/cyd_esp32_2432s028/main/touch.c).
+   Exit criterion: read touch coordinates, map to 320×240.
+4. **SD card + exFAT:** install SdFat via Arduino Library Manager. Mount a 1 TB
+   SDXC card (exFAT), write + read a test file. Exit criterion:
+   `sd.begin(SdioConfig(FIFO_SDIO))` succeeds on a 1 TB card, `file.open`
+   + `file.write` + `file.read` round-trips.
+
+### Phase 2: Crypto stack port
+
+1. **secp256k1:** build `libsecp256k1` for ARM Cortex-M7 (no ASM, pure C with
+   `USE_NUM_NONE` / `USE_FIELD_INV_BUILTIN`). Verify schnorr sign/verify +
+   ECDSA sign/verify against known test vectors.
+2. **ed25519 / x25519:** use a portable ed25519 (e.g. the ref10 impl or
+   `crypto_mbedtls` if mbedtls is available for Teensy — alternatively
+   [`micro-ecc`](https://github.com/kmackay/micro-ecc) + a portable ed25519).
+   Verify against the host's test vectors.
+3. **PQClean:** compile `resources/pqclean/` (ML-DSA-65, SLH-DSA-128s,
+   ML-KEM-768) for Cortex-M7. The `crypto_backend` abstraction needs a Teensy
+   backend (`crypto_backend_sdfat.c` or reuse the vendored Keccak from
+   [`resources/pqclean/common/crypto_backend_mbedtls.c`](../resources/pqclean/common/crypto_backend_mbedtls.c)
+   — the Keccak core is portable C). SHA-256/512 via SdFat's built-in or a
+   portable impl. Verify keygen + sign + verify against the host.
+4. **nostr_core_lib:** compile [`resources/nostr_core_lib/`](../resources/nostr_core_lib/)
+   (nip004, nip044, nostr_common, utils, crypto) for Cortex-M7. This is
+   portable C and should compile as-is.
+
+### Phase 3: Key derivation + mnemonic
+
+1. Port [`firmware/cyd_esp32_2432s028/main/key_derivation.c`](../firmware/cyd_esp32_2432s028/main/key_derivation.c)
+   (BIP-32/SLIP-0010 derivation for all 6 algorithms). Replace mbedtls/PSA
+   calls with the portable crypto from Phase 2.
+2. Port [`firmware/cyd_esp32_2432s028/main/mnemonic.c`](../firmware/cyd_esp32_2432s028/main/mnemonic.c)
+   (BIP-39 wordlist + validation + mnemonic_to_seed via PBKDF2-HMAC-SHA512).
+3. Port [`firmware/cyd_esp32_2432s028/main/bech32.c`](../firmware/cyd_esp32_2432s028/main/bech32.c)
+   (npub encoding).
+
+### Phase 4: OTP pad from SDXC (the key feature)
+
+1. **`otp_pad_sd.cpp`:**
+   - `otp_pad_init()`: mount the SD card via `sd.begin(SdioConfig(FIFO_SDIO))`,
+     open `/pad.bin` for reading, open `/pad.offset` for the persistent offset.
+     Read the offset file on boot; if absent, start at 0.
+   - `otp_pad_read(buf, len)`: seek to the current offset in `/pad.bin`, read
+     `len` bytes, advance the offset. If the offset + len exceeds the file
+     size, return an error (pad exhausted).
+   - `otp_pad_persist_offset()`: write the current offset to `/pad.offset`
+     after each `encrypt`/`decrypt` call (or batch: persist every N calls to
+     reduce SD wear).
+   - `otp_pad_zeroize()`: close files, zeroize in-RAM state.
+2. **Wire into the `encrypt`/`decrypt` verbs:** replace the CYD's
+   HKDF-derived in-RAM pad with `otp_pad_read()`. The wire contract is
+   unchanged (`encrypt`/`decrypt` with `algorithm:"otp"`, base64 payload,
+   `pad_offset` in the response).
+3. **UI:** show "reading pad from SD…" during the read (the SD read is fast
+   but the user should see activity). Show the pad offset + remaining bytes on
+   the idle screen.
+
+### Phase 5: Transport + dispatch + UI
+
+1. **Transport (`transport.cpp`):** TinyUSB CDC-ACM + 4-byte length-prefix
+   framing (same as [`firmware/cyd_esp32_2432s028/main/uart_transport.c`](../firmware/cyd_esp32_2432s028/main/uart_transport.c)).
+   Optionally add a WebUSB vendor interface for browser transport (the Teensy's
+   Hi-Speed USB makes this fast).
+2. **Dispatch (`dispatch.cpp`):** port `handle_request()` from
+   [`firmware/cyd_esp32_2432s028/main/main.c`](../firmware/cyd_esp32_2432s028/main/main.c)
+   — the entire verb dispatch (all nostr_* + algorithm-based verbs, enforcement
+   matrix, structured results, auth envelope verify). This is the bulk of the
+   logic and ports nearly verbatim (only the crypto backend calls change).
+3. **UI (`ui.cpp`):** port [`firmware/cyd_esp32_2432s028/main/ui.c`](../firmware/cyd_esp32_2432s028/main/ui.c)
+   (LVGL 8.3 or hand-rolled). The UI screens are: startup menu → generate
+   mnemonic → confirm mnemonic → enter mnemonic → idle (show npub + pad offset)
+   → approval prompt. The Teensy's 600 MHz M7 makes LVGL snappy.
+
+### Phase 6: Integration + testing
+
+1. **End-to-end smoke test:** load a mnemonic, exercise every verb over USB
+   CDC with a Python script or the Web Serial test page
+   ([`examples/cyd_webserial_demo.html`](../examples/cyd_webserial_demo.html)
+   works for any CDC device).
+2. **OTP pad test:** place a known pad file on the 1 TB SDXC card, run
+   `encrypt` + `decrypt` round-trips, verify the XOR is correct and the offset
+   advances + persists across power cycles.
+3. **Cross-board parity:** same mnemonic on the Teensy 4.1 and the CYD → same
+   npub, same secp256k1/ed25519/x25519/PQ public keys, same signatures.
+4. **Performance:** measure SLH-DSA-128s sign time (expect ~1-2 s vs 5-30 s on
+   ESP32), ML-DSA-65 sign time (expect ~50 ms), SD pad read throughput.
+
+## Open questions / decisions
+
+- **UI framework:** LVGL 8.3 (heavier, proven on CYD) vs hand-rolled (lighter,
+  faster to port, no external dep). The Teensy has enough RAM for LVGL. **Lean
+  toward LVGL** for consistency with the CYD.
+- **ed25519/x25519 impl:** mbedtls is available for Teensy via the
+  `mbedtls` Arduino library, but PSA crypto is not. Options: (a) mbedtls
+  ed25519 (if the Arduino mbedtls has it), (b) a portable ed25519 like
+  [`orlp/ed25519`](https://github.com/orlp/ed25519) + micro-ecc for x25519,
+  (c) libsodium for Teensy. **Investigate (a) first, fall back to (b).**
+- **Toolchain:** Arduino CLI + Teensyduino (simplest, SdFat + USB stack
+  included) vs PlatformIO (better dependency management, CI-friendly). **Lean
+  toward Arduino CLI** for the initial port, migrate to PlatformIO later.
+- **Offset persistence frequency:** writing `/pad.offset` to SD after every
+  `encrypt`/`decrypt` is safe but wears the SD. **Batch: persist every 16
+  calls, and also on idle timeout.** If power is lost, at most 16 pad bytes are
+  reused (acceptable for a signing device, not for a high-volume OTP channel).
+
+## Verification
+
+- `arduino-cli compile` (or `pio run`) builds clean for `teensy:avr:teensy41`.
+- Flash to the Teensy 4.1, load a mnemonic, exercise every verb over USB CDC.
+- 1 TB SDXC card mounts, `/pad.bin` reads at >20 MB/s, offset persists across
+  power cycles.
+- Same mnemonic → same keys as the CYD and the host n_signer.
+- SLH-DSA-128s signs in <3 s (vs 5-30 s on ESP32).

plans/tui_display_connections_on_demand.md

@@ -0,0 +1,151 @@
+# Plan: Move Connection Instructions to On-Demand Display
+
+## Problem
+
+The Connections section in the running TUI is verbose and confusing. It mixes server addresses with client command examples, and when multiple transports are active (Unix + TCP + HTTP) it takes up a large chunk of the status screen, pushing the Roles and Activity sections down. The connection instructions are only needed once when a user wants to know how to reach the signer — they don't need to be permanently visible.
+
+## Solution
+
+Remove the Connections section from the default `render_status()` display. Add a new hotkey **`d`** (display connection instructions) that prints the connection info on demand, then returns to the normal status view on the next refresh/keystroke.
+
+## Design
+
+### Default status display (after change)
+
+The Connections section is removed. The display shows: Roles, Activity, status line, hotkey menu. A one-line hint at the top reminds the user that `d` shows connection instructions.
+
+```text
+================================================================================
+                                n_signer v0.0.53
+================================================================================
+> Main Menu
+
+Press d for connection instructions
+
+Roles
+Role                 Purpose      Curve        Selector
+-------------------- ------------ ------------ ------------
+main                 nostr        secp256k1    nostr_index
+ops                  nostr        secp256k1    nostr_index
+backup               bitcoin      secp256k1    role_path
+
+Activity (latest first)
+16:03:11  allow  caller=uid:1000  method=get_public_key role=main
+16:02:44  prompt caller=uid:1000  method=sign_event role=ops
+16:02:46  allow  caller=uid:1000  method=sign_event role=ops
+15:59:10  deny   caller=uid:1001  method=sign_event error=unauthorized
+
+session=unlocked (12 words) signer=nsigner_hairy_dog derived=3 auto-approve=OFF
+
+l lock/reunlock
+r refresh
+a toggle auto-approve
+d display connections
+q/x quit
+```
+
+### On-demand connection display (press `d`)
+
+When the user presses `d`, the screen clears and shows **only** the connection instructions, with clear spacing between transports. Each transport block shows the **connection string** (the address/endpoint to reach), a blank line, then an **Example:** with the client command indented beneath. No "Server:" / "Client:" labels — just the address and an example. A footer tells the user how to return.
+
+```text
+================================================================================
+                                n_signer v0.0.53
+================================================================================
+> Connection Instructions
+
+
+Unix socket
+
+  @nsigner_hairy_dog
+
+  Example:
+    nsigner --socket-name nsigner_hairy_dog client '<json>'
+
+  Qrexec (bridge-source-trusted):
+    qrexec-client-vm <target_qube> qubes.NsignerRpc
+
+
+FIPS
+
+  http://npub10vt4scusw6lq27qw83nfwp5sqer492h0tnwa8ugqjvp6l4xuz2qsdycrwd.fips:11111
+
+  Example:
+    curl -X POST http://npub10vt4scusw6lq27qw83nfwp5sqer492h0tnwa8ugqjvp6l4xuz2qsdycrwd.fips:11111/ \
+      -H 'Content-Type: application/json' \
+      -d '<json>'
+
+
+HTTP
+
+  http://127.0.0.1:11112
+
+  Example:
+    curl -X POST http://127.0.0.1:11112/ \
+      -H 'Content-Type: application/json' \
+      -d '<json>'
+
+
+OTP pad: 333e9902db839d9d... (offset 288 / 1048576 bytes)
+
+session=unlocked (12 words) signer=nsigner_hairy_dog derived=3 auto-approve=OFF
+
+Press any key to return
+```
+
+### Key differences from current display
+
+1. **Spacing between transports** — each transport gets its own titled block with blank lines separating it from the next, instead of a flat list of `Server:` / `Client:` lines.
+2. **Connection string + example, no labels** — each block shows the bare connection string (e.g. `http://127.0.0.1:11112`), then an `Example:` with the client command indented beneath. No confusing "Server:" / "Client:" labels.
+3. **On-demand only** — the default running display no longer shows connections at all, just a one-line hint. The user presses `d` when they need the instructions, reads them, then presses any key to return.
+4. **OTP pad status** — shown at the bottom of the connection display (it's connection-related: which pad is bound and how much has been consumed).
+
+## Implementation Steps
+
+1. **[`src/main.c`](src/main.c) — `render_status()`** (line 1451):
+   - Remove the Connections section (lines 1464-1471).
+   - Add a one-line hint after the top frame: `tui_print("Press d for connection instructions");`
+   - Add a blank line after the hint.
+
+2. **[`src/main.c`](src/main.c) — new function `render_connections()`**:
+   - Clears the screen and renders the top frame.
+   - Iterates `g_connection_info` but formats it with the spaced layout shown above. Since `g_connection_info` already stores formatted strings like `"Server: unix @nsigner_hairy_dog"` and `"  Client: nsigner --socket-name ... client '<json>'"`, either:
+     - **Option A**: Reformat the stored strings into blocks by detecting `Server:` lines as transport boundaries and printing blank lines + indentation.
+     - **Option B**: Store connection info in a structured form (transport type, server address, client command(s)) and render the block layout from the structured data.
+   - Option B is cleaner but requires changing `connection_info_add()` and all its call sites. Option A is a smaller change. **Recommend Option A** for now — parse the existing flat list into blocks.
+   - **FIPS section**: The connection string is the npub-based FIPS URL (`http://<npub>.fips:<port>`), which FIPS resolves to the signer's TCP endpoint. The example uses `curl` since FIPS makes the endpoint HTTP-reachable for clients with FIPS installed. The raw TCP bind address (`tcp:[::]:11111`) is not shown — it's an implementation detail; the npub URL is what clients use.
+   - Print OTP pad status if bound.
+   - Print the status line at the bottom.
+   - Print "Press any key to return" footer.
+
+3. **[`src/main.c`](src/main.c) — `g_main_menu_items`** (line 825):
+   - Add `{"^_d^: display connections", 'd'}` to the menu array.
+
+4. **[`src/main.c`](src/main.c) — event loop** (line ~3068, the stdin keystroke handler):
+   - Add a case for `'d'`:
+     - Call `render_connections()`.
+     - Read one keystroke from stdin (blocking `read()`).
+     - Call `render_status()` to return to the normal display.
+
+5. **[`README.md`](README.md) §3.2**:
+   - Update the example TUI layout to match the new default display (no Connections section, `d` in hotkeys).
+   - Add a note that pressing `d` shows the connection instructions.
+
+6. **[`api.md`](api.md) §5 Transports**:
+   - No changes needed — the transport documentation is already separate from the TUI display.
+
+## Files Changed
+
+| File | Change |
+|------|--------|
+| [`src/main.c`](src/main.c) | Remove Connections from `render_status()`, add `render_connections()`, add `d` hotkey + menu item + event loop case |
+| [`README.md`](README.md) | Update §3.2 example display to match new layout |
+| [`api.md`](api.md) | No changes |
+
+## Verification
+
+- `make dev` builds clean.
+- Start nsigner with all transports selected. Default display shows no Connections section, just the "Press d for connection instructions" hint.
+- Press `d` — connection instructions appear with clear spacing between transports.
+- Press any key — returns to normal status display.
+- All other hotkeys (`l`, `r`, `a`, `q`) still work.

src/enforcement.c

@@ -202,43 +202,35 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_UNKNOWN_VERB -3 /* verb not recognized */
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
-/* New algorithm-based verb defines (algorithm is a parameter, not implicit) */
+/* Algorithm-based verb defines (algorithm is a parameter, not implicit).
+ * Callers must supply `algorithm` explicitly — no implicit defaults. */
 #define VERB_SIGN              "sign"
 #define VERB_VERIFY            "verify"
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
-
-#define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
-
-/* New algorithm-based verb defines (algorithm is a parameter, not implicit) */
-#define VERB_SIGN              "sign"
-#define VERB_VERIFY            "verify"
-#define VERB_ENCAPSULATE       "encapsulate"
-#define VERB_DECAPSULATE       "decapsulate"
-#define VERB_DERIVE_SHARED     "derive_shared_secret"
-
-
-/* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
+#define VERB_DERIVE          "derive"
 #define VERB_GET_PUBLIC_KEY    "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+
+/* Nostr protocol verbs (secp256k1 NIP-06, role-based selector). */
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
+
+/* OTP verbs (one-time pad; selected via algorithm:"otp"). */
+#define VERB_ENCRYPT        "encrypt"
+#define VERB_DECRYPT        "decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -637,7 +629,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {
@@ -710,69 +702,17 @@ int socket_name_random(char *out, size_t out_len);
 
 #include <string.h>
 
+/* Check whether a verb is a Nostr protocol verb (role-based, secp256k1 NIP-06). */
 static int is_nostr_verb(const char *verb) {
     if (verb == NULL) {
         return 0;
     }
-
-    /* get_public_key is a universal verb — allowed for all algorithms.
-     * It is handled separately in enforce_verb_role() and excluded here. */
-    return (strcmp(verb, VERB_SIGN_EVENT) == 0) ||
-           (strcmp(verb, VERB_NIP44_ENCRYPT) == 0) ||
-           (strcmp(verb, VERB_NIP44_DECRYPT) == 0) ||
-           (strcmp(verb, VERB_NIP04_ENCRYPT) == 0) ||
-           (strcmp(verb, VERB_NIP04_DECRYPT) == 0) ||
-           (strcmp(verb, VERB_MINE_EVENT) == 0);
-}
-
-static int is_sign_data_verb(const char *verb) {
-    if (verb == NULL) {
-        return 0;
-    }
-    return (strcmp(verb, VERB_SIGN_DATA) == 0) ||
-           (strcmp(verb, VERB_VERIFY_SIG) == 0);
-}
-
-static int is_kem_verb(const char *verb) {
-    if (verb == NULL) {
-        return 0;
-    }
-    return (strcmp(verb, VERB_KEM_ENCAPS) == 0) ||
-           (strcmp(verb, VERB_KEM_DECAPS) == 0);
-}
-
-/* Check whether a (purpose, curve) pair is allowed for sign_data / verify_signature.
- * Returns ENFORCE_OK, ENFORCE_ERR_PURPOSE, or ENFORCE_ERR_CURVE. */
-static int enforce_sign_data_role(const role_entry_t *role) {
-    switch (role->purpose) {
-        case PURPOSE_SSH:
-            if (role->curve == CURVE_ED25519) {
-                return ENFORCE_OK;
-            }
-            return ENFORCE_ERR_CURVE;
-
-        case PURPOSE_PQ_SIG:
-            if (role->curve == CURVE_ML_DSA_65 ||
-                role->curve == CURVE_SLH_DSA_128S) {
-                return ENFORCE_OK;
-            }
-            return ENFORCE_ERR_CURVE;
-
-        default:
-            return ENFORCE_ERR_PURPOSE;
-    }
-}
-
-/* Check whether a (purpose, curve) pair is allowed for kem_encapsulate/decapsulate.
- * Returns ENFORCE_OK, ENFORCE_ERR_PURPOSE, or ENFORCE_ERR_CURVE. */
-static int enforce_kem_role(const role_entry_t *role) {
-    if (role->purpose != PURPOSE_PQ_KEM) {
-        return ENFORCE_ERR_PURPOSE;
-    }
-    if (role->curve != CURVE_ML_KEM_768) {
-        return ENFORCE_ERR_CURVE;
-    }
-    return ENFORCE_OK;
+    return (strcmp(verb, VERB_NOSTR_SIGN_EVENT) == 0) ||
+           (strcmp(verb, VERB_NOSTR_MINE_EVENT) == 0) ||
+           (strcmp(verb, VERB_NOSTR_NIP44_ENCRYPT) == 0) ||
+           (strcmp(verb, VERB_NOSTR_NIP44_DECRYPT) == 0) ||
+           (strcmp(verb, VERB_NOSTR_NIP04_ENCRYPT) == 0) ||
+           (strcmp(verb, VERB_NOSTR_NIP04_DECRYPT) == 0);
 }
 
 int enforce_verb_role(const char *verb, const role_entry_t *role) {
@@ -780,14 +720,15 @@ int enforce_verb_role(const char *verb, const role_entry_t *role) {
         return ENFORCE_ERR_UNKNOWN_VERB;
     }
 
-    /* get_public_key is a universal verb — allowed for any role whose
-     * (curve, purpose) maps to a known algorithm via crypto_alg_from_role().
-     * This lets clients retrieve public keys for all 6 algorithms. */
-    if (strcmp(verb, VERB_GET_PUBLIC_KEY) == 0) {
-        crypto_alg_t alg = crypto_alg_from_role(role->curve, role->purpose);
-        if (alg == CRYPTO_ALG_UNKNOWN) {
+    /* nostr_get_public_key: returns the role's secp256k1 (NIP-06) public key.
+     * Requires PURPOSE_NOSTR + CURVE_SECP256K1. */
+    if (strcmp(verb, VERB_NOSTR_GET_PUBLIC_KEY) == 0) {
+        if (role->purpose != PURPOSE_NOSTR) {
             return ENFORCE_ERR_PURPOSE;
         }
+        if (role->curve != CURVE_SECP256K1) {
+            return ENFORCE_ERR_CURVE;
+        }
         return ENFORCE_OK;
     }
 
@@ -802,41 +743,25 @@ int enforce_verb_role(const char *verb, const role_entry_t *role) {
         return ENFORCE_OK;
     }
 
-    /* ssh_sign: PURPOSE_SSH + CURVE_ED25519 only. */
-    if (strcmp(verb, VERB_SSH_SIGN) == 0) {
-        if (role->purpose != PURPOSE_SSH) {
-            return ENFORCE_ERR_PURPOSE;
-        }
-        if (role->curve != CURVE_ED25519) {
-            return ENFORCE_ERR_CURVE;
-        }
-        return ENFORCE_OK;
-    }
-
-    /* sign_data / verify_signature: SSH+ed25519 or PQ-SIG algorithms. */
-    if (is_sign_data_verb(verb)) {
-        return enforce_sign_data_role(role);
-    }
-
-    /* kem_encapsulate / kem_decapsulate: PQ-KEM + ML-KEM-768 only. */
-    if (is_kem_verb(verb)) {
-        return enforce_kem_role(role);
-    }
-
+    /* All other verbs (sign, verify, encapsulate, decapsulate,
+     * derive_shared_secret, get_public_key, encrypt, decrypt) are
+     * algorithm-based and handled by enforce_verb_algorithm() before
+     * role resolution. Anything reaching here is unrecognized. */
     return ENFORCE_ERR_UNKNOWN_VERB;
 }
 
-/* ---- Algorithm-based enforcement (new) ----
+/* ---- Algorithm-based enforcement ----
  *
  * enforce_verb_algorithm() checks whether a verb is valid for a given
  * algorithm, WITHOUT consulting the role table or purpose field. This is
- * the enforcement path for the new algorithm-based verbs (sign, verify,
+ * the enforcement path for the algorithm-based verbs (sign, verify,
  * encapsulate, decapsulate, derive_shared_secret, get_public_key).
  *
- * The Nostr-specific verbs (sign_event, nip44_*, nip04_*, mine_event) are
- * always secp256k1 — that's a Nostr protocol requirement, not a policy
- * choice. They are accepted here only when alg == CRYPTO_ALG_SECP256K1
- * so that algorithm-based policy entries can approve them too.
+ * The Nostr-specific verbs (nostr_sign_event, nostr_nip44_*, nostr_nip04_*,
+ * nostr_mine_event) are always secp256k1 — that's a Nostr protocol
+ * requirement, not a policy choice. They are accepted here only when
+ * alg == CRYPTO_ALG_SECP256K1 so that algorithm-based policy entries can
+ * approve them too.
  */
 int enforce_verb_algorithm(const char *verb, crypto_alg_t alg) {
     if (verb == NULL) {
@@ -878,17 +803,22 @@ int enforce_verb_algorithm(const char *verb, crypto_alg_t alg) {
         return ENFORCE_ERR_ALGORITHM;
     }
 
-    /* Nostr verbs: always secp256k1 (protocol requirement). */
-    if (is_nostr_verb(verb) || strcmp(verb, VERB_MINE_EVENT) == 0) {
+    /* derive: HMAC-SHA256(privkey, data). secp256k1 only (32-byte scalar key). */
+    if (strcmp(verb, VERB_DERIVE) == 0) {
+        if (alg == CRYPTO_ALG_SECP256K1) {
+            return ENFORCE_OK;
+        }
+        return ENFORCE_ERR_ALGORITHM;
+    }
+
+    /* Nostr verbs: always secp256k1 (protocol requirement). */
+    if (is_nostr_verb(verb)) {
         if (alg == CRYPTO_ALG_SECP256K1) {
             return ENFORCE_OK;
         }
         return ENFORCE_ERR_ALGORITHM;
     }
 
-    /* Old verb aliases map to the new verbs and are handled by the
-     * dispatcher before reaching enforcement. If they reach here,
-     * treat them as unknown (the dispatcher should have remapped). */
     return ENFORCE_ERR_UNKNOWN_VERB;
 }
 

src/http_listener.c

@@ -0,0 +1,220 @@
+/*
+ * http_listener.c — minimal HTTP/1.1 parser for n_signer's HTTP listener mode.
+ *
+ * Only supports POST with a JSON body. No chunked encoding, no keep-alive,
+ * no static file serving. One request per connection (connection close after
+ * response).
+ *
+ * This is intentionally minimal — n_signer is a signer, not a web server.
+ */
+#define _POSIX_C_SOURCE 200809L
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+
+/* ------------------------------------------------------------------ */
+/* Read a line from fd into buf (up to buf_size-1 chars, NUL-terminated).
+ * Returns line length (excluding NUL) on success, -1 on error/EOF.
+ * The line includes the trailing \r\n if present. */
+static int read_line_fd(int fd, char *buf, size_t buf_size) {
+    size_t pos = 0;
+    while (pos < buf_size - 1) {
+        char c;
+        ssize_t n = read(fd, &c, 1);
+        if (n <= 0) {
+            if (pos == 0) return -1;
+            break;
+        }
+        buf[pos++] = c;
+        if (c == '\n') break;
+    }
+    buf[pos] = '\0';
+    return (int)pos;
+}
+
+/* Read exactly n bytes from fd into buf. Returns 0 on success, -1 on error. */
+static int read_n_bytes(int fd, char *buf, size_t n) {
+    size_t got = 0;
+    while (got < n) {
+        ssize_t r = read(fd, buf + got, n - got);
+        if (r <= 0) return -1;
+        got += (size_t)r;
+    }
+    return 0;
+}
+
+/* Write all bytes to fd. Returns 0 on success, -1 on error. */
+static int write_all(int fd, const char *buf, size_t len) {
+    size_t put = 0;
+    while (put < len) {
+        ssize_t w = write(fd, buf + put, len - put);
+        if (w <= 0) {
+            if (errno == EINTR) continue;
+            return -1;
+        }
+        put += (size_t)w;
+    }
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Public API                                                         */
+/* ------------------------------------------------------------------ */
+
+/*
+ * Read an HTTP POST request from fd and return the JSON body.
+ *
+ * On success returns 0 and sets *out_body to a malloc'd NUL-terminated
+ * string (caller frees). Returns -1 on error.
+ */
+int http_recv_request(int fd, char **out_body, size_t max_body_size) {
+    char line[2048];
+    long content_length = -1;
+    int is_post = 0;
+
+    if (!out_body) return -1;
+    *out_body = NULL;
+
+    /* Read request line: "METHOD PATH HTTP/1.1\r\n" */
+    if (read_line_fd(fd, line, sizeof(line)) < 0) {
+        return -1;
+    }
+    /* Parse method. */
+    if (strncmp(line, "POST", 4) == 0) {
+        is_post = 1;
+    } else if (strncmp(line, "OPTIONS", 7) == 0) {
+        /* CORS preflight — read remaining headers, then return a special
+         * marker so the caller can send CORS headers. */
+        while (read_line_fd(fd, line, sizeof(line)) > 0) {
+            if (strcmp(line, "\r\n") == 0 || strcmp(line, "\n") == 0) break;
+        }
+        *out_body = strdup("");  /* empty body signals OPTIONS */
+        return 0;
+    }
+
+    if (!is_post) {
+        /* Not POST — read remaining headers so we can send a 405. */
+        while (read_line_fd(fd, line, sizeof(line)) > 0) {
+            if (strcmp(line, "\r\n") == 0 || strcmp(line, "\n") == 0) break;
+        }
+        return -2;  /* method not allowed */
+    }
+
+    /* Read headers until empty line. */
+    while (read_line_fd(fd, line, sizeof(line)) > 0) {
+        /* Strip trailing \r\n. */
+        size_t len = strlen(line);
+        while (len > 0 && (line[len-1] == '\r' || line[len-1] == '\n')) {
+            line[--len] = '\0';
+        }
+        if (len == 0) break;  /* end of headers */
+
+        /* Parse Content-Length (case-insensitive). */
+        if (strncasecmp(line, "Content-Length:", 15) == 0) {
+            const char *p = line + 15;
+            while (*p == ' ' || *p == '\t') p++;
+            content_length = atol(p);
+        }
+    }
+
+    if (content_length < 0) {
+        return -3;  /* missing Content-Length */
+    }
+    if ((size_t)content_length > max_body_size) {
+        /* Drain the body so the connection isn't left half-open. */
+        char tmp[4096];
+        long remaining = content_length;
+        while (remaining > 0) {
+            size_t to_read = (size_t)remaining;
+            if (to_read > sizeof(tmp)) to_read = sizeof(tmp);
+            ssize_t r = read(fd, tmp, to_read);
+            if (r <= 0) break;
+            remaining -= r;
+        }
+        return -4;  /* body too large */
+    }
+
+    /* Read the body. */
+    char *body = (char *)malloc((size_t)content_length + 1);
+    if (!body) return -1;
+    if (read_n_bytes(fd, body, (size_t)content_length) != 0) {
+        free(body);
+        return -1;
+    }
+    body[content_length] = '\0';
+    *out_body = body;
+    return 0;
+}
+
+/*
+ * Send an HTTP response with a JSON body.
+ */
+int http_send_response(int fd, const char *json_body) {
+    if (!json_body) json_body = "";
+    size_t body_len = strlen(json_body);
+
+    char header[512];
+    int hlen = snprintf(header, sizeof(header),
+        "HTTP/1.1 200 OK\r\n"
+        "Content-Type: application/json\r\n"
+        "Content-Length: %zu\r\n"
+        "Access-Control-Allow-Origin: *\r\n"
+        "Access-Control-Allow-Methods: POST, OPTIONS\r\n"
+        "Access-Control-Allow-Headers: Content-Type\r\n"
+        "Connection: close\r\n"
+        "\r\n",
+        body_len);
+
+    if (write_all(fd, header, (size_t)hlen) != 0) return -1;
+    if (write_all(fd, json_body, body_len) != 0) return -1;
+    return 0;
+}
+
+/*
+ * Send an HTTP error response.
+ */
+int http_send_error(int fd, int status, const char *message) {
+    if (!message) message = "error";
+    char body[512];
+    int blen = snprintf(body, sizeof(body),
+        "{\"error\":{\"code\":%d,\"message\":\"%s\"}}", status, message);
+
+    char header[512];
+    int hlen = snprintf(header, sizeof(header),
+        "HTTP/1.1 %d %s\r\n"
+        "Content-Type: application/json\r\n"
+        "Content-Length: %d\r\n"
+        "Access-Control-Allow-Origin: *\r\n"
+        "Connection: close\r\n"
+        "\r\n",
+        status,
+        (status == 405) ? "Method Not Allowed" :
+        (status == 413) ? "Payload Too Large" :
+        (status == 400) ? "Bad Request" : "Internal Server Error",
+        blen);
+
+    if (write_all(fd, header, (size_t)hlen) != 0) return -1;
+    if (write_all(fd, body, (size_t)blen) != 0) return -1;
+    return 0;
+}
+
+/*
+ * Send a CORS preflight response (for OPTIONS requests).
+ */
+int http_send_cors_preflight(int fd) {
+    const char *resp =
+        "HTTP/1.1 204 No Content\r\n"
+        "Access-Control-Allow-Origin: *\r\n"
+        "Access-Control-Allow-Methods: POST, OPTIONS\r\n"
+        "Access-Control-Allow-Headers: Content-Type\r\n"
+        "Access-Control-Max-Age: 86400\r\n"
+        "Content-Length: 0\r\n"
+        "Connection: close\r\n"
+        "\r\n";
+    return write_all(fd, resp, strlen(resp));
+}

src/http_listener.h

@@ -0,0 +1,40 @@
+/*
+ * http_listener.h — minimal HTTP/1.1 parser for n_signer's HTTP listener mode.
+ */
+#ifndef NSIGNER_HTTP_LISTENER_H
+#define NSIGNER_HTTP_LISTENER_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Read an HTTP POST request from fd and return the JSON body.
+ * On success returns 0 and sets *out_body to a malloc'd NUL-terminated
+ * string (caller frees). Returns -1 on read error, -2 on method not allowed,
+ * -3 on missing Content-Length, -4 on body too large.
+ */
+int http_recv_request(int fd, char **out_body, size_t max_body_size);
+
+/*
+ * Send an HTTP 200 response with a JSON body.
+ */
+int http_send_response(int fd, const char *json_body);
+
+/*
+ * Send an HTTP error response.
+ */
+int http_send_error(int fd, int status, const char *message);
+
+/*
+ * Send a CORS preflight response (for OPTIONS requests).
+ */
+int http_send_cors_preflight(int fd);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NSIGNER_HTTP_LISTENER_H */

src/key_store.c

@@ -210,20 +210,17 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
@@ -612,7 +609,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/mnemonic.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -631,7 +634,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/otp_pad.c

@@ -0,0 +1,585 @@
+/*
+ * otp_pad.c — OTP pad state for n_signer.
+ *
+ * One pad per session (by design — see plans/otp_nostr_integration.md).
+ * The pad is bound at startup via otp_pad_bind() and accessed by the
+ * otp encrypt / otp decrypt dispatcher verbs via otp_pad_get_state().
+ *
+ * The pad file is opened read-only and kept open for the lifetime of the
+ * process. The per-pad .state file (offset counter) is read and written
+ * via libotppad. Offset writes are atomic (temp + rename) inside libotppad.
+ *
+ * Pad bytes are never loaded whole into RAM. Each request seeks to the
+ * current offset and reads exactly the slice it needs into a small
+ * mlock'd scratch buffer.
+ */
+#define _POSIX_C_SOURCE 200809L
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <errno.h>
+
+#include "libotppad.h"
+#include "otp_pad.h"
+
+/* from secure_mem.h (headerless decls pattern) */
+extern void secure_memzero(void *ptr, size_t len);
+
+/* ------------------------------------------------------------------ */
+/* OTP pad state                                                      */
+/* ------------------------------------------------------------------ */
+
+#define OTP_PAD_DIR_MAX     512
+#define OTP_PAD_CHKSUM_MAX  128
+#define OTP_PAD_PATH_MAX    (OTP_PAD_DIR_MAX + OTP_PAD_CHKSUM_MAX + 16)
+#define OTP_SCRATCH_MAX     (4 * 1024 * 1024)  /* 4 MB max chunk */
+
+typedef struct {
+    int      bound;                          /* 1 if a pad is bound */
+    char     pads_dir[OTP_PAD_DIR_MAX];      /* directory holding .pad/.state */
+    char     chksum[OTP_PAD_CHKSUM_MAX];     /* 64-hex-char pad checksum */
+    char     pad_path[OTP_PAD_PATH_MAX];     /* full path to .pad file */
+    FILE    *pad_fp;                         /* read-only FILE* on .pad */
+    uint64_t pad_size;                       /* total pad file size in bytes */
+    int      allow_blkback;                  /* 1 if --otp-allow-blkback passed */
+    /* mlock'd scratch buffer for XOR */
+    void    *scratch_data;
+    size_t   scratch_size;
+    int      scratch_locked;
+} otp_pad_state_t;
+
+static otp_pad_state_t g_otp_pad = {0};
+
+otp_pad_state_t *otp_pad_get_state(void) {
+    return &g_otp_pad;
+}
+
+int otp_pad_is_bound(void) {
+    return g_otp_pad.bound;
+}
+
+const char *otp_pad_chksum(void) {
+    return g_otp_pad.bound ? g_otp_pad.chksum : NULL;
+}
+
+const char *otp_pad_dir(void) {
+    return g_otp_pad.bound ? g_otp_pad.pads_dir : NULL;
+}
+
+/* ------------------------------------------------------------------ */
+/* Removable-mount check (Qubes guard)                                */
+/* ------------------------------------------------------------------ */
+
+/* Return 1 if `path` lives on a blkback device (e.g. /dev/xvdi via qvm-block),
+ * 0 if it's a directly-owned device (e.g. /dev/sda via PCI passthrough),
+ * -1 on error. Best-effort: compares the fs source device name. */
+static int is_blkback_mount(const char *path) {
+    struct stat st;
+    if (stat(path, &st) != 0) return -1;
+
+    /* Read the mount source for the filesystem containing `path`. */
+    FILE *mtab = fopen("/proc/mounts", "r");
+    if (!mtab) return -1;
+
+    char line[1024];
+    int found = 0;
+    int is_blkback = 0;
+    size_t best_len = 0;
+
+    while (fgets(line, sizeof(line), mtab)) {
+        char source[512], mount[512], fstype[64];
+        if (sscanf(line, "%511s %511s %63s", source, mount, fstype) < 3) continue;
+        size_t mlen = strlen(mount);
+        /* Pick the longest matching mount prefix. */
+        if (strncmp(path, mount, mlen) == 0 &&
+            (path[mlen] == '/' || path[mlen] == '\0') &&
+            mlen > best_len) {
+            best_len = mlen;
+            found = 1;
+            /* blkback devices show up as /dev/xvd* in the guest. */
+            is_blkback = (strncmp(source, "/dev/xvd", 8) == 0);
+        }
+    }
+    fclose(mtab);
+    if (!found) return -1;
+    return is_blkback;
+}
+
+/* ------------------------------------------------------------------ */
+/* Find a pad by chksum prefix in pads_dir                            */
+/* ------------------------------------------------------------------ */
+
+/* Resolve a chksum-or-prefix to a full 64-char chksum by scanning pads_dir.
+ * Returns 0 on success and fills `out_chksum` (must be >= OTP_PAD_CHKSUM_MAX).
+ * Returns -1 if not found, -2 if ambiguous (multiple matches). */
+static int resolve_pad_chksum(const char *pads_dir, const char *prefix,
+                              char *out_chksum) {
+    DIR *d = opendir(pads_dir);
+    if (!d) return -1;
+
+    struct dirent *e;
+    int matches = 0;
+    char found[OTPPAD_CHKSUM_HEX_LEN + 1] = {0};
+    size_t plen = strlen(prefix);
+
+    while ((e = readdir(d)) != NULL) {
+        size_t nlen = strlen(e->d_name);
+        if (nlen < 5 || strcmp(e->d_name + nlen - 4, ".pad") != 0) continue;
+        size_t base_len = nlen - 4;  /* without ".pad" */
+        if (base_len != OTPPAD_CHKSUM_HEX_LEN) continue;
+        if (plen == 0 || strncmp(e->d_name, prefix, plen) == 0) {
+            memcpy(found, e->d_name, base_len);
+            found[base_len] = '\0';
+            matches++;
+        }
+    }
+    closedir(d);
+
+    if (matches == 0) return -1;
+    if (matches > 1) return -2;
+    strncpy(out_chksum, found, OTPPAD_CHKSUM_HEX_LEN);
+    out_chksum[OTPPAD_CHKSUM_HEX_LEN] = '\0';
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Bind / unbind                                                      */
+/* ------------------------------------------------------------------ */
+
+/* Bind a pad at startup. Returns 0 on success, non-zero on error.
+ * `pads_dir` is the directory containing <chksum>.pad and <chksum>.state.
+ * `pad_spec` is a full 64-char chksum or a unique prefix.
+ * `allow_blkback` non-zero skips the blkback guard (for qvm-block testing). */
+int otp_pad_bind(const char *pads_dir, const char *pad_spec, int allow_blkback) {
+    if (!pads_dir || !pad_spec) return 1;
+    if (g_otp_pad.bound) return 2;  /* already bound */
+
+    /* Removable-mount guard. */
+    int blkback = is_blkback_mount(pads_dir);
+    if (blkback < 0) {
+        /* Could not determine — warn but continue (best-effort). */
+        fprintf(stderr, "otp_pad: warning: could not determine mount type for %s\n",
+                pads_dir);
+    } else if (blkback && !allow_blkback) {
+        fprintf(stderr, "otp_pad: %s is on a blkback device (qvm-block).\n",
+                pads_dir);
+        fprintf(stderr, "  Refusing to bind for pad secrecy. Use PCI USB "
+                        "controller passthrough, or pass --otp-allow-blkback "
+                        "to override (not recommended for production pads).\n");
+        return 3;
+    }
+
+    /* Resolve the pad chksum. */
+    char chksum[OTPPAD_CHKSUM_HEX_LEN + 1];
+    if (strlen(pad_spec) == OTPPAD_CHKSUM_HEX_LEN) {
+        strncpy(chksum, pad_spec, OTPPAD_CHKSUM_HEX_LEN);
+        chksum[OTPPAD_CHKSUM_HEX_LEN] = '\0';
+        /* Verify the file exists. */
+        char path[OTP_PAD_PATH_MAX];
+        snprintf(path, sizeof(path), "%s/%s.pad", pads_dir, chksum);
+        if (access(path, R_OK) != 0) {
+            fprintf(stderr, "otp_pad: pad file not found: %s\n", path);
+            return 4;
+        }
+    } else {
+        int r = resolve_pad_chksum(pads_dir, pad_spec, chksum);
+        if (r == -1) {
+            fprintf(stderr, "otp_pad: no pad matching prefix '%s' in %s\n",
+                    pad_spec, pads_dir);
+            return 5;
+        } else if (r == -2) {
+            fprintf(stderr, "otp_pad: ambiguous pad prefix '%s' (multiple matches)\n",
+                    pad_spec);
+            return 6;
+        }
+    }
+
+    /* Build the pad path and open it read-only. */
+    char pad_path[OTP_PAD_PATH_MAX];
+    snprintf(pad_path, sizeof(pad_path), "%s/%s.pad", pads_dir, chksum);
+
+    FILE *fp = fopen(pad_path, "rb");
+    if (!fp) {
+        fprintf(stderr, "otp_pad: cannot open %s: %s\n", pad_path, strerror(errno));
+        return 7;
+    }
+
+    /* Determine pad size. */
+    struct stat st;
+    if (fstat(fileno(fp), &st) != 0) {
+        fprintf(stderr, "otp_pad: fstat failed: %s\n", strerror(errno));
+        fclose(fp);
+        return 8;
+    }
+    if (st.st_size < (off_t)OTPPAD_HEADER_RESERVED) {
+        fprintf(stderr, "otp_pad: pad too small (%lld bytes, need >= %d)\n",
+                (long long)st.st_size, OTPPAD_HEADER_RESERVED);
+        fclose(fp);
+        return 9;
+    }
+
+    /* Verify the pad checksum matches the filename. */
+    char computed[OTPPAD_CHKSUM_HEX_LEN + 1];
+    if (otppad_checksum(pad_path, computed) != 0) {
+        fprintf(stderr, "otp_pad: checksum computation failed\n");
+        fclose(fp);
+        return 10;
+    }
+    if (strcmp(computed, chksum) != 0) {
+        fprintf(stderr, "otp_pad: checksum mismatch (file says %s, computed %s)\n",
+                chksum, computed);
+        fclose(fp);
+        return 11;
+    }
+
+    /* Read the current offset. */
+    uint64_t offset;
+    if (otppad_state_read(pads_dir, chksum, &offset) != 0) {
+        /* No state file — initialize at the reserved header. */
+        offset = OTPPAD_HEADER_RESERVED;
+        if (otppad_state_write(pads_dir, chksum, offset) != 0) {
+            fprintf(stderr, "otp_pad: cannot write initial state file\n");
+            fclose(fp);
+            return 12;
+        }
+    }
+    if (offset < OTPPAD_HEADER_RESERVED) {
+        fprintf(stderr, "otp_pad: offset %llu < reserved header %d\n",
+                (unsigned long long)offset, OTPPAD_HEADER_RESERVED);
+        fclose(fp);
+        return 13;
+    }
+    if (offset > (uint64_t)st.st_size) {
+        fprintf(stderr, "otp_pad: offset %llu past end of pad (%lld)\n",
+                (unsigned long long)offset, (long long)st.st_size);
+        fclose(fp);
+        return 14;
+    }
+
+    /* Commit. */
+    strncpy(g_otp_pad.pads_dir, pads_dir, OTP_PAD_DIR_MAX - 1);
+    strncpy(g_otp_pad.chksum, chksum, OTP_PAD_CHKSUM_MAX - 1);
+    strncpy(g_otp_pad.pad_path, pad_path, OTP_PAD_PATH_MAX - 1);
+    g_otp_pad.pad_fp = fp;
+    g_otp_pad.pad_size = (uint64_t)st.st_size;
+    g_otp_pad.allow_blkback = allow_blkback;
+    g_otp_pad.bound = 1;
+
+    fprintf(stderr, "otp_pad: bound pad %s (%llu bytes, offset=%llu)\n",
+            chksum, (unsigned long long)st.st_size,
+            (unsigned long long)offset);
+    return 0;
+}
+
+void otp_pad_unbind(void) {
+    if (g_otp_pad.pad_fp) {
+        fclose(g_otp_pad.pad_fp);
+        g_otp_pad.pad_fp = NULL;
+    }
+    if (g_otp_pad.scratch_data) {
+        secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        if (g_otp_pad.scratch_locked) {
+            munlock(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        }
+        free(g_otp_pad.scratch_data);
+        g_otp_pad.scratch_data = NULL;
+        g_otp_pad.scratch_size = 0;
+        g_otp_pad.scratch_locked = 0;
+    }
+    secure_memzero(&g_otp_pad, sizeof(g_otp_pad));
+}
+
+/* ------------------------------------------------------------------ */
+/* Core encrypt/decrypt transform                                     */
+/* ------------------------------------------------------------------ */
+
+/* Ensure the scratch buffer is at least `size` bytes, mlock'd. */
+static int ensure_scratch(size_t size) {
+    if (size > OTP_SCRATCH_MAX) return -1;
+    if (g_otp_pad.scratch_size >= size && g_otp_pad.scratch_data) return 0;
+    /* Grow. */
+    if (g_otp_pad.scratch_data) {
+        secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        if (g_otp_pad.scratch_locked) {
+            munlock(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        }
+        free(g_otp_pad.scratch_data);
+        g_otp_pad.scratch_data = NULL;
+        g_otp_pad.scratch_size = 0;
+        g_otp_pad.scratch_locked = 0;
+    }
+    g_otp_pad.scratch_data = malloc(size);
+    if (!g_otp_pad.scratch_data) return -2;
+    g_otp_pad.scratch_size = size;
+    if (mlock(g_otp_pad.scratch_data, size) == 0) {
+        g_otp_pad.scratch_locked = 1;
+    }
+    return 0;
+}
+
+/* Read `len` bytes from the pad at `offset` into `out` (must be mlock'd by
+ * caller). Returns 0 on success, non-zero on error. */
+static int read_pad_slice(uint64_t offset, size_t len, unsigned char *out) {
+    if (!g_otp_pad.pad_fp) return -1;
+    if (fseek(g_otp_pad.pad_fp, (long)offset, SEEK_SET) != 0) return -2;
+    size_t got = fread(out, 1, len, g_otp_pad.pad_fp);
+    if (got != len) return -3;
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Public encrypt/decrypt entrypoints (called by dispatcher verbs)   */
+/* ------------------------------------------------------------------ */
+
+/* OTPPAD_ENCRYPT_OK etc. are returned via *out_result. */
+
+/* Encrypt: takes plaintext bytes, returns malloc'd ASCII armor or binary blob.
+ *
+ * `encoding` is "ascii" or "binary".
+ * On success returns 0 and sets *out_payload (malloc'd, caller frees),
+ * *out_payload_len, and *out_new_offset.
+ */
+int otp_pad_encrypt(const unsigned char *plaintext, size_t pt_len,
+                    const char *encoding,
+                    char **out_payload, size_t *out_payload_len,
+                    uint64_t *out_new_offset) {
+    if (!g_otp_pad.bound) return 1;  /* not bound */
+    if (!plaintext || !out_payload || !out_payload_len || !out_new_offset) return 2;
+    *out_payload = NULL;
+    *out_payload_len = 0;
+
+    /* Pad the plaintext. */
+    size_t chunk = otppad_chunk_size(pt_len);
+    if (ensure_scratch(chunk) != 0) return 3;
+    unsigned char *buf = (unsigned char *)g_otp_pad.scratch_data;
+    memcpy(buf, plaintext, pt_len);
+    if (otppad_pad_apply(buf, pt_len, chunk) != 0) return 4;
+
+    /* Read current offset. */
+    uint64_t offset;
+    if (otppad_state_read(g_otp_pad.pads_dir, g_otp_pad.chksum, &offset) != 0) {
+        return 5;
+    }
+    if (offset + chunk > g_otp_pad.pad_size) {
+        return 6;  /* pad exhausted */
+    }
+
+    /* Read the pad slice into a second scratch buffer. */
+    /* Reuse the same scratch: read pad into second half, XOR in place.
+     * For simplicity, allocate a separate pad-slice buffer. */
+    unsigned char *pad_slice = (unsigned char *)malloc(chunk);
+    if (!pad_slice) return 7;
+    if (read_pad_slice(offset, chunk, pad_slice) != 0) {
+        free(pad_slice);
+        return 8;
+    }
+
+    /* XOR. */
+    for (size_t i = 0; i < chunk; i++) {
+        buf[i] ^= pad_slice[i];
+    }
+    secure_memzero(pad_slice, chunk);
+    free(pad_slice);
+
+    /* Advance offset atomically. */
+    uint64_t new_offset = offset + chunk;
+    if (otppad_state_write(g_otp_pad.pads_dir, g_otp_pad.chksum, new_offset) != 0) {
+        return 9;
+    }
+
+    /* Encode output. */
+    if (encoding && strcmp(encoding, "binary") == 0) {
+        /* Binary .otp: header + encrypted (padded) data. */
+        otppad_bin_header_t hdr;
+        memset(&hdr, 0, sizeof(hdr));
+        memcpy(hdr.magic, OTPPAD_MAGIC, OTPPAD_MAGIC_LEN);
+        hdr.version = OTPPAD_FORMAT_VERSION;
+        /* pad_chksum is binary 32 bytes — convert hex to bytes. */
+        for (int i = 0; i < OTPPAD_CHKSUM_BIN_LEN; i++) {
+            unsigned int byte;
+            sscanf(g_otp_pad.chksum + i * 2, "%02x", &byte);
+            hdr.pad_chksum[i] = (unsigned char)byte;
+        }
+        hdr.pad_offset = offset;
+        hdr.file_mode = 0644;
+        hdr.file_size = pt_len;  /* original (unpadded) size */
+
+        /* Build the blob in memory (avoid fmemopen — it can misbehave
+         * with NUL bytes on some platforms). */
+        size_t blob_size = 58 + chunk;
+        unsigned char *blob = (unsigned char *)malloc(blob_size);
+        if (!blob) return 10;
+        unsigned char *p = blob;
+        memcpy(p, OTPPAD_MAGIC, 4); p += 4;
+        memcpy(p, &hdr.version, 2); p += 2;
+        memcpy(p, hdr.pad_chksum, OTPPAD_CHKSUM_BIN_LEN); p += OTPPAD_CHKSUM_BIN_LEN;
+        memcpy(p, &hdr.pad_offset, 8); p += 8;
+        memcpy(p, &hdr.file_mode, 4); p += 4;
+        memcpy(p, &hdr.file_size, 8); p += 8;
+        /* p is now at byte 58. Copy the encrypted (padded) data. */
+        memcpy(p, buf, chunk);
+        *out_payload = (char *)blob;
+        *out_payload_len = blob_size;
+    } else {
+        /* ASCII armor. */
+        char *armor = NULL;
+        if (otppad_armor_generate(NSIGNER_OTP_VERSION, g_otp_pad.chksum, offset,
+                                  buf, chunk, &armor) != 0) {
+            return 14;
+        }
+        *out_payload = armor;
+        *out_payload_len = strlen(armor);
+    }
+
+    *out_new_offset = new_offset;
+    secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+    return 0;
+}
+
+/* Decrypt: takes ASCII armor or binary blob, returns malloc'd plaintext.
+ *
+ * `encoding` is "ascii" or "binary" (auto-detected if NULL).
+ * On success returns 0 and sets *out_plaintext (malloc'd, caller frees),
+ * *out_pt_len.
+ */
+int otp_pad_decrypt(const char *input, size_t input_len,
+                    const char *encoding,
+                    unsigned char **out_plaintext, size_t *out_pt_len) {
+    if (!g_otp_pad.bound) return 1;
+    if (!input || !out_plaintext || !out_pt_len) return 2;
+    *out_plaintext = NULL;
+    *out_pt_len = 0;
+
+    uint64_t offset;
+    size_t chunk;
+    unsigned char *ciphertext = NULL;
+    size_t ct_len = 0;
+
+    int is_binary;
+    if (encoding && strcmp(encoding, "binary") == 0) {
+        is_binary = 1;
+    } else if (encoding && strcmp(encoding, "ascii") == 0) {
+        is_binary = 0;
+    } else {
+        /* Auto-detect by magic bytes. */
+        is_binary = (input_len >= 4 && memcmp(input, OTPPAD_MAGIC, 4) == 0);
+    }
+
+    if (!is_binary) {
+        /* ASCII armor. */
+        char chksum[OTPPAD_CHKSUM_HEX_LEN + 1];
+        char b64[65536];
+        if (otppad_armor_parse(input, chksum, &offset, b64, sizeof(b64)) != 0) {
+            return 3;
+        }
+        if (strcmp(chksum, g_otp_pad.chksum) != 0) {
+            return 4;  /* pad mismatch */
+        }
+        int dlen = 0;
+        ciphertext = otppad_base64_decode(b64, &dlen);
+        if (!ciphertext) return 5;
+        ct_len = (size_t)dlen;
+        chunk = ct_len;
+    } else {
+        /* Binary .otp blob — parse directly from the buffer (avoid fmemopen
+         * which can misbehave with NUL bytes on some platforms). */
+        if (input_len < 58) return 6;
+        const unsigned char *p = (const unsigned char *)input;
+        otppad_bin_header_t hdr;
+        memset(&hdr, 0, sizeof(hdr));
+        memcpy(hdr.magic, p, 4); p += 4;
+        memcpy(&hdr.version, p, 2); p += 2;
+        memcpy(hdr.pad_chksum, p, OTPPAD_CHKSUM_BIN_LEN); p += OTPPAD_CHKSUM_BIN_LEN;
+        memcpy(&hdr.pad_offset, p, 8); p += 8;
+        memcpy(&hdr.file_mode, p, 4); p += 4;
+        memcpy(&hdr.file_size, p, 8); p += 8;
+        /* p is now at byte 58. */
+        if (memcmp(hdr.magic, OTPPAD_MAGIC, OTPPAD_MAGIC_LEN) != 0) {
+            return 8;
+        }
+        /* Convert binary chksum to hex for comparison. */
+        char chksum_hex[OTPPAD_CHKSUM_HEX_LEN + 1];
+        for (int i = 0; i < OTPPAD_CHKSUM_BIN_LEN; i++) {
+            sprintf(chksum_hex + i * 2, "%02x", hdr.pad_chksum[i]);
+        }
+        chksum_hex[OTPPAD_CHKSUM_HEX_LEN] = '\0';
+        if (strcmp(chksum_hex, g_otp_pad.chksum) != 0) {
+            return 9;
+        }
+        offset = hdr.pad_offset;
+        /* Remaining bytes after the 58-byte header are the ciphertext. */
+        ct_len = input_len - 58;
+        chunk = ct_len;
+        ciphertext = (unsigned char *)malloc(ct_len);
+        if (!ciphertext) return 10;
+        memcpy(ciphertext, p, ct_len);
+    }
+
+    if (ensure_scratch(chunk) != 0) {
+        free(ciphertext); return 12;
+    }
+    unsigned char *buf = (unsigned char *)g_otp_pad.scratch_data;
+
+    /* Read pad slice. */
+    unsigned char *pad_slice = (unsigned char *)malloc(chunk);
+    if (!pad_slice) { free(ciphertext); return 13; }
+    if (read_pad_slice(offset, chunk, pad_slice) != 0) {
+        free(pad_slice); free(ciphertext); return 14;
+    }
+
+    /* XOR (in-place into scratch). */
+    for (size_t i = 0; i < chunk; i++) {
+        buf[i] = ciphertext[i] ^ pad_slice[i];
+    }
+    secure_memzero(pad_slice, chunk);
+    free(pad_slice);
+    secure_memzero(ciphertext, ct_len);
+    free(ciphertext);
+
+    /* Strip padding. */
+    size_t pt_len;
+    if (otppad_pad_remove(buf, chunk, &pt_len) != 0) {
+        secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        return 15;
+    }
+
+    /* Return plaintext. */
+    unsigned char *pt = (unsigned char *)malloc(pt_len ? pt_len : 1);
+    if (!pt) {
+        secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+        return 16;
+    }
+    memcpy(pt, buf, pt_len);
+    secure_memzero(g_otp_pad.scratch_data, g_otp_pad.scratch_size);
+
+    *out_plaintext = pt;
+    *out_pt_len = pt_len;
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+/* Helpers for the dispatcher                                         */
+/* ------------------------------------------------------------------ */
+
+uint64_t otp_pad_current_offset(void) {
+    if (!g_otp_pad.bound) return 0;
+    uint64_t off;
+    if (otppad_state_read(g_otp_pad.pads_dir, g_otp_pad.chksum, &off) != 0) {
+        return 0;
+    }
+    return off;
+}
+
+uint64_t otp_pad_size(void) {
+    return g_otp_pad.bound ? g_otp_pad.pad_size : 0;
+}

src/otp_pad.h

@@ -0,0 +1,76 @@
+/*
+ * otp_pad.h — OTP pad state for n_signer (one pad per session).
+ *
+ * Bound at startup via otp_pad_bind(); accessed by the otp encrypt /
+ * otp decrypt dispatcher verbs. See plans/otp_nostr_integration.md.
+ */
+#ifndef NSIGNER_OTP_PAD_H
+#define NSIGNER_OTP_PAD_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Version string stamped into ASCII-armored output. */
+#define NSIGNER_OTP_VERSION "v0.0.2-otp"
+
+/* Returns 1 if a pad has been bound at startup, 0 otherwise. */
+int otp_pad_is_bound(void);
+
+/* Return the bound pad's 64-char hex checksum, or NULL if unbound. */
+const char *otp_pad_chksum(void);
+
+/* Return the bound pad's directory, or NULL if unbound. */
+const char *otp_pad_dir(void);
+
+/* Current offset (bytes consumed) of the bound pad, or 0 if unbound. */
+uint64_t otp_pad_current_offset(void);
+
+/* Total size in bytes of the bound pad, or 0 if unbound. */
+uint64_t otp_pad_size(void);
+
+/*
+ * Bind a pad at startup. Returns 0 on success, non-zero on error.
+ * `pads_dir` is the directory containing <chksum>.pad and <chksum>.state.
+ * `pad_spec` is a full 64-char chksum or a unique prefix.
+ * `allow_blkback` non-zero skips the blkback guard (for qvm-block testing).
+ */
+int otp_pad_bind(const char *pads_dir, const char *pad_spec, int allow_blkback);
+
+/* Unbind and zeroize all pad state. Idempotent. */
+void otp_pad_unbind(void);
+
+/*
+ * Encrypt plaintext bytes with the bound pad.
+ *
+ * `encoding` is "ascii" (default) or "binary".
+ * On success returns 0 and sets:
+ *   *out_payload     — malloc'd, caller frees (NUL-terminated for ascii)
+ *   *out_payload_len — length of payload
+ *   *out_new_offset  — pad offset after this encryption
+ */
+int otp_pad_encrypt(const unsigned char *plaintext, size_t pt_len,
+                    const char *encoding,
+                    char **out_payload, size_t *out_payload_len,
+                    uint64_t *out_new_offset);
+
+/*
+ * Decrypt a ciphertext (ASCII armor or binary .otp blob) with the bound pad.
+ *
+ * `encoding` is "ascii", "binary", or NULL (auto-detect by magic bytes).
+ * On success returns 0 and sets:
+ *   *out_plaintext — malloc'd, caller frees
+ *   *out_pt_len    — length of plaintext
+ */
+int otp_pad_decrypt(const char *input, size_t input_len,
+                    const char *encoding,
+                    unsigned char **out_plaintext, size_t *out_pt_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NSIGNER_OTP_PAD_H */

src/policy.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -631,7 +634,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/pq_crypto.c

@@ -221,6 +221,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -230,22 +231,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -671,7 +674,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/role_table.c

@@ -211,6 +211,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -220,22 +221,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -634,7 +637,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/secure_mem.c

@@ -210,6 +210,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -219,22 +220,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -633,7 +636,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/selector.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -631,7 +634,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

src/server.c

@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include <sys/types.h>
 #include <cJSON.h>
+#include "http_listener.h"
 
 /* from secure_mem.h */
 
@@ -213,6 +214,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -222,22 +224,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -644,12 +648,13 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 #define NSIGNER_LISTEN_UNIX   0
 #define NSIGNER_LISTEN_STDIO  1
 #define NSIGNER_LISTEN_QREXEC 2
 #define NSIGNER_LISTEN_TCP    3
+#define NSIGNER_LISTEN_HTTP   4
 
 #define NSIGNER_AUTH_OFF      0
 #define NSIGNER_AUTH_OPTIONAL 1
@@ -1449,13 +1454,25 @@ int server_start(server_ctx_t *ctx) {
         return 0;
     }
 
-    if (ctx->listen_mode == NSIGNER_LISTEN_TCP) {
+    if (ctx->listen_mode == NSIGNER_LISTEN_TCP ||
+        ctx->listen_mode == NSIGNER_LISTEN_HTTP) {
         int family;
         uint16_t port;
         char host[64];
         int one = 1;
+        int bind_attempt;
+        int bound = 0;
 
-        int prc = parse_tcp_target(ctx->socket_name, &family, host, sizeof(host), &port);
+        /* HTTP mode uses the same TCP socket setup, just with an "http:" prefix
+         * instead of "tcp:". Convert to tcp: for parse_tcp_target. */
+        char tcp_target[128];
+        if (ctx->listen_mode == NSIGNER_LISTEN_HTTP) {
+            snprintf(tcp_target, sizeof(tcp_target), "tcp:%s", ctx->socket_name + 5);
+        } else {
+            snprintf(tcp_target, sizeof(tcp_target), "%s", ctx->socket_name);
+        }
+
+        int prc = parse_tcp_target(tcp_target, &family, host, sizeof(host), &port);
         if (prc != 0) {
             (void)snprintf(ctx->last_error,
                            sizeof(ctx->last_error),
@@ -1464,6 +1481,18 @@ int server_start(server_ctx_t *ctx) {
             return -1;
         }
 
+        /* Try the requested port, then increment up to 5 times if it's in use.
+         * This handles both real conflicts and false positives (e.g. when TCP
+         * [::]:11111 and HTTP 127.0.0.1:11111 are started together in
+         * multi-listen mode, the second bind can fail with EADDRINUSE even
+         * though no other process holds the port). */
+        for (bind_attempt = 0; bind_attempt < 5 && !bound; ++bind_attempt) {
+            uint16_t try_port = (uint16_t)(port + bind_attempt);
+            if (try_port < port) {
+                /* port wrapped past 65535 — stop retrying */
+                break;
+            }
+
             fd = socket(family, SOCK_STREAM, 0);
             if (fd < 0) {
                 (void)snprintf(ctx->last_error,
@@ -1479,7 +1508,7 @@ int server_start(server_ctx_t *ctx) {
                 struct sockaddr_in addr4;
                 memset(&addr4, 0, sizeof(addr4));
                 addr4.sin_family = AF_INET;
-            addr4.sin_port = htons(port);
+                addr4.sin_port = htons(try_port);
                 if (inet_pton(AF_INET, host, &addr4.sin_addr) != 1) {
                     close(fd);
                     server_set_error(ctx, "inet_pton(AF_INET) failed for listen target");
@@ -1492,13 +1521,16 @@ int server_start(server_ctx_t *ctx) {
                                    ctx->socket_name,
                                    strerror(errno));
                     close(fd);
+                    if (errno == EADDRINUSE) {
+                        continue;  /* try next port */
+                    }
                     return -1;
                 }
             } else {
                 struct sockaddr_in6 addr6;
                 memset(&addr6, 0, sizeof(addr6));
                 addr6.sin6_family = AF_INET6;
-            addr6.sin6_port = htons(port);
+                addr6.sin6_port = htons(try_port);
                 if (inet_pton(AF_INET6, host, &addr6.sin6_addr) != 1) {
                     close(fd);
                     server_set_error(ctx, "inet_pton(AF_INET6) failed for listen target");
@@ -1511,10 +1543,36 @@ int server_start(server_ctx_t *ctx) {
                                    ctx->socket_name,
                                    strerror(errno));
                     close(fd);
+                    if (errno == EADDRINUSE) {
+                        continue;  /* try next port */
+                    }
                     return -1;
                 }
             }
 
+            bound = 1;
+            port = try_port;
+        }
+
+        if (!bound) {
+            /* All 5 attempts failed with EADDRINUSE. ctx->last_error already
+             * holds the most recent bind failure message. */
+            return -1;
+        }
+
+        /* Update ctx->socket_name to reflect the actual bound port, so the
+         * status display and error messages show the real address. */
+        {
+            const char *prefix = (ctx->listen_mode == NSIGNER_LISTEN_HTTP) ? "http:" : "tcp:";
+            if (family == AF_INET6) {
+                snprintf(ctx->socket_name, sizeof(ctx->socket_name),
+                         "%s[%s]:%u", prefix, host, (unsigned)port);
+            } else {
+                snprintf(ctx->socket_name, sizeof(ctx->socket_name),
+                         "%s%s:%u", prefix, host, (unsigned)port);
+            }
+        }
+
         if (listen(fd, 16) != 0) {
             (void)snprintf(ctx->last_error,
                            sizeof(ctx->last_error),
@@ -1705,7 +1763,7 @@ int server_get_caller(int fd, caller_identity_t *out) {
     return 0;
 }
 
-/* ---- Async mine_event support ---- */
+/* ---- Async nostr_mine_event support ---- */
 
 typedef struct {
     int client_fd;
@@ -1775,6 +1833,14 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
             }
             return -1;
         }
+        /* Set client fd to blocking mode (the listen socket is non-blocking,
+         * and accept() may inherit that flag on some platforms). */
+        {
+            int cflags = fcntl(client_fd, F_GETFL, 0);
+            if (cflags >= 0) {
+                (void)fcntl(client_fd, F_SETFL, cflags & ~O_NONBLOCK);
+            }
+        }
     }
 
     if (server_get_caller(client_fd, &caller) != 0) {
@@ -1784,6 +1850,12 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
         return -1;
     }
 
+    /* HTTP mode: override caller kind so auth envelopes are not required
+     * (HTTP relies on localhost binding + policy/approval prompts). */
+    if (ctx->listen_mode == NSIGNER_LISTEN_HTTP) {
+        caller.kind = NSIGNER_LISTEN_HTTP;
+    }
+
     /*
      * Bridge-source-trusted path: when the unix listener is marked as a
      * trusted bridge socket (started with --bridge-source-trusted), each
@@ -1839,7 +1911,30 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
         cJSON_Delete(proot);
     }
 
-    if (transport_recv_framed(client_fd, &request, SERVER_MAX_MSG_SIZE) != 0) {
+    int is_http = (ctx->listen_mode == NSIGNER_LISTEN_HTTP);
+
+    if (is_http) {
+        /* HTTP mode: parse the HTTP request to get the JSON body. */
+        int http_rc = http_recv_request(client_fd, &request, SERVER_MAX_MSG_SIZE);
+        if (http_rc == 0 && request != NULL && request[0] == '\0') {
+            /* OPTIONS preflight — send CORS headers. */
+            (void)http_send_cors_preflight(client_fd);
+            free(request);
+            close(client_fd);
+            return 1;
+        }
+        if (http_rc != 0 || request == NULL) {
+            if (http_rc == -2) {
+                (void)http_send_error(client_fd, 405, "method_not_allowed");
+            } else if (http_rc == -4) {
+                (void)http_send_error(client_fd, 413, "payload_too_large");
+            } else {
+                (void)http_send_error(client_fd, 400, "bad_request");
+            }
+            if (client_fd != STDIN_FILENO) close(client_fd);
+            return 1;
+        }
+    } else if (transport_recv_framed(client_fd, &request, SERVER_MAX_MSG_SIZE) != 0) {
         response = strdup("{\"id\":\"null\",\"error\":{\"code\":-32700,\"message\":\"parse_error\"}}");
         if (response != NULL) {
             (void)transport_send_framed((client_fd == STDIN_FILENO) ? STDOUT_FILENO : client_fd, response);
@@ -1899,7 +1994,11 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
                     response = strdup(errbuf);
                 }
                 if (response != NULL) {
+                    if (is_http) {
+                        (void)http_send_response(client_fd, response);
+                    } else {
                         (void)transport_send_framed((client_fd == STDIN_FILENO) ? STDOUT_FILENO : client_fd, response);
+                    }
                     free(response);
                 }
                 free(request);
@@ -2036,12 +2135,12 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
 
     if (pchk == POLICY_ALLOW && !derivation_error) {
         /*
-         * mine_event is a long-running operation (potentially seconds to minutes).
+         * nostr_mine_event is a long-running operation (potentially seconds to minutes).
          * Spawn a detached thread so the server stays responsive. The thread
          * owns the client_fd and request, and sends the response when mining
          * completes. We skip the synchronous response path below.
          */
-        if (strcmp(method, "mine_event") == 0 && client_fd != STDIN_FILENO) {
+        if (strcmp(method, "nostr_mine_event") == 0 && client_fd != STDIN_FILENO) {
             mine_thread_arg_t *marg = malloc(sizeof(mine_thread_arg_t));
             if (marg != NULL) {
                 pthread_t mine_tid;
@@ -2092,8 +2191,12 @@ int server_handle_one(server_ctx_t *ctx, server_activity_cb cb, void *cb_data) {
     }
 
     if (response != NULL) {
+        if (is_http) {
+            (void)http_send_response(client_fd, response);
+        } else {
             (void)transport_send_framed((client_fd == STDIN_FILENO) ? STDOUT_FILENO : client_fd, response);
         }
+    }
 
     if (pchk == POLICY_ALLOW && policy_src == POLICY_SOURCE_PREAPPROVE) {
         source_label = "preapprove";
@@ -2135,7 +2238,9 @@ void server_stop(server_ctx_t *ctx) {
     }
 
     if (ctx->listen_fd >= 0) {
-        if (ctx->listen_mode == NSIGNER_LISTEN_UNIX || ctx->listen_mode == NSIGNER_LISTEN_TCP) {
+        if (ctx->listen_mode == NSIGNER_LISTEN_UNIX ||
+            ctx->listen_mode == NSIGNER_LISTEN_TCP ||
+            ctx->listen_mode == NSIGNER_LISTEN_HTTP) {
             close(ctx->listen_fd);
         }
         ctx->listen_fd = -1;

src/socket_name.c

@@ -210,6 +210,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -219,22 +220,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -633,7 +636,7 @@ char *dispatcher_handle_request(dispatcher_ctx_t *ctx, const char *json_request)
 
 
 #define SERVER_SOCKET_NAME_MAX 108
-#define SERVER_MAX_MSG_SIZE    65536
+#define SERVER_MAX_MSG_SIZE    16777216
 
 /* Caller identity */
 typedef struct {

tests/test.sh

@@ -78,31 +78,31 @@ else
 fi
 
 echo
-echo "[2/7] sign_event"
+echo "[2/7] nostr_sign_event"
 now_ts="$(date +%s)"
 event_json='{"kind":1,"content":"hello from tests/test.sh","tags":[],"created_at":__TS__}'
 event_json="${event_json/__TS__/${now_ts}}"
 escaped_event_json="${event_json//\"/\\\"}"
-req_sign="{\"id\":\"2\",\"method\":\"sign_event\",\"params\":[\"${escaped_event_json}\",{\"role\":\"main\"}]}"
+req_sign="{\"id\":\"2\",\"method\":\"nostr_sign_event\",\"params\":[\"${escaped_event_json}\",{\"role\":\"main\"}]}"
 resp_sign="$(run_request "$req_sign")"
 echo "request : $req_sign"
 echo "response: $resp_sign"
 if printf '%s' "$resp_sign" | grep -q '"result"'; then
-  echo "[ok] sign_event returned result"
+  echo "[ok] nostr_sign_event returned result"
 else
-  echo "[warn] sign_event did not return result"
+  echo "[warn] nostr_sign_event did not return result"
 fi
 
 echo
-echo "[3/7] sign_event with nostr_index=0"
-req_sign_idx="{\"id\":\"3\",\"method\":\"sign_event\",\"params\":[\"${escaped_event_json}\",{\"nostr_index\":0}]}"
+echo "[3/7] nostr_sign_event with nostr_index=0"
+req_sign_idx="{\"id\":\"3\",\"method\":\"nostr_sign_event\",\"params\":[\"${escaped_event_json}\",{\"nostr_index\":0}]}"
 resp_sign_idx="$(run_request "$req_sign_idx")"
 echo "request : $req_sign_idx"
 echo "response: $resp_sign_idx"
 
 echo
 echo "[4/7] role selector error case (unknown role)"
-req_bad_role='{"id":"4","method":"sign_event","params":["{}",{"role":"does_not_exist"}]}'
+req_bad_role='{"id":"4","method":"nostr_nostr_sign_event","params":["{}",{"role":"does_not_exist"}]}'
 resp_bad_role="$(run_request "$req_bad_role")"
 echo "request : $req_bad_role"
 echo "response: $resp_bad_role"
@@ -115,13 +115,13 @@ fi
 echo
 echo "[5/7] NIP-04 self round-trip"
 if [[ -n "$pubkey" ]]; then
-  req_nip04_enc="{\"id\":\"5\",\"method\":\"nip04_encrypt\",\"params\":[\"${pubkey}\",\"hello_nip04_from_test_sh\"]}"
+  req_nip04_enc="{\"id\":\"5\",\"method\":\"nostr_nostr_nip04_encrypt\",\"params\":[\"${pubkey}\",\"hello_nip04_from_test_sh\"]}"
   resp_nip04_enc="$(run_request "$req_nip04_enc")"
   echo "request : $req_nip04_enc"
   echo "response: $resp_nip04_enc"
   cipher_nip04="$(printf '%s' "$resp_nip04_enc" | extract_result_string)"
   if [[ -n "$cipher_nip04" ]]; then
-    req_nip04_dec="{\"id\":\"6\",\"method\":\"nip04_decrypt\",\"params\":[\"${pubkey}\",\"${cipher_nip04}\"]}"
+    req_nip04_dec="{\"id\":\"6\",\"method\":\"nostr_nostr_nip04_decrypt\",\"params\":[\"${pubkey}\",\"${cipher_nip04}\"]}"
     resp_nip04_dec="$(run_request "$req_nip04_dec")"
     echo "request : $req_nip04_dec"
     echo "response: $resp_nip04_dec"
@@ -140,13 +140,13 @@ fi
 echo
 echo "[6/7] NIP-44 self round-trip"
 if [[ -n "$pubkey" ]]; then
-  req_nip44_enc="{\"id\":\"7\",\"method\":\"nip44_encrypt\",\"params\":[\"${pubkey}\",\"hello_nip44_from_test_sh\"]}"
+  req_nip44_enc="{\"id\":\"7\",\"method\":\"nostr_nostr_nip44_encrypt\",\"params\":[\"${pubkey}\",\"hello_nip44_from_test_sh\"]}"
   resp_nip44_enc="$(run_request "$req_nip44_enc")"
   echo "request : $req_nip44_enc"
   echo "response: $resp_nip44_enc"
   cipher_nip44="$(printf '%s' "$resp_nip44_enc" | extract_result_string)"
   if [[ -n "$cipher_nip44" ]]; then
-    req_nip44_dec="{\"id\":\"8\",\"method\":\"nip44_decrypt\",\"params\":[\"${pubkey}\",\"${cipher_nip44}\"]}"
+    req_nip44_dec="{\"id\":\"8\",\"method\":\"nostr_nostr_nip44_decrypt\",\"params\":[\"${pubkey}\",\"${cipher_nip44}\"]}"
     resp_nip44_dec="$(run_request "$req_nip44_dec")"
     echo "request : $req_nip44_dec"
     echo "response: $resp_nip44_dec"

tests/test_algorithm_api.c

@@ -74,18 +74,15 @@ role_curve_t role_curve_from_str(const char *s);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
-#define VERB_SIGN_EVENT     "sign_event"
+#define VERB_DERIVE          "derive"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
 
@@ -367,12 +364,20 @@ int main(void) {
           enforce_verb_algorithm(VERB_DERIVE_SHARED, CRYPTO_ALG_X25519) == ENFORCE_OK);
     check("enforce derive_shared_secret + ed25519 -> ALGORITHM err",
           enforce_verb_algorithm(VERB_DERIVE_SHARED, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
+    check("enforce derive + secp256k1 -> OK",
+          enforce_verb_algorithm(VERB_DERIVE, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
+    check("enforce derive + ed25519 -> ALGORITHM err",
+          enforce_verb_algorithm(VERB_DERIVE, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
+    check("enforce derive + x25519 -> ALGORITHM err",
+          enforce_verb_algorithm(VERB_DERIVE, CRYPTO_ALG_X25519) == ENFORCE_ERR_ALGORITHM);
+    check("enforce derive + ml-kem-768 -> ALGORITHM err",
+          enforce_verb_algorithm(VERB_DERIVE, CRYPTO_ALG_ML_KEM_768) == ENFORCE_ERR_ALGORITHM);
     check("enforce get_public_key + any alg -> OK",
           enforce_verb_algorithm(VERB_GET_PUBLIC_KEY, CRYPTO_ALG_ED25519) == ENFORCE_OK);
-    check("enforce sign_event + secp256k1 -> OK",
-          enforce_verb_algorithm(VERB_SIGN_EVENT, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
-    check("enforce sign_event + ed25519 -> ALGORITHM err",
-          enforce_verb_algorithm(VERB_SIGN_EVENT, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
+    check("enforce nostr_sign_event + secp256k1 -> OK",
+          enforce_verb_algorithm(VERB_NOSTR_SIGN_EVENT, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
+    check("enforce nostr_sign_event + ed25519 -> ALGORITHM err",
+          enforce_verb_algorithm(VERB_NOSTR_SIGN_EVENT, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
 
     /* ---- get_public_key with algorithm parameter ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
@@ -588,51 +593,51 @@ int main(void) {
           resp_has(resp, "algorithm_not_supported_for_verb") || resp_has(resp, "\"code\":1010"));
     free(resp);
 
-    /* ---- Old verb alias: sign_data with algorithm=ed25519 ---- */
+    /* ---- Verb: sign with algorithm=ed25519 ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
-        "{\"id\":\"alias1\",\"method\":\"sign_data\",\"params\":[\"68656c6c6f\",{\"algorithm\":\"ed25519\",\"index\":0}]}");
-    check("sign_data alias with algorithm=ed25519 returns result",
+        "{\"id\":\"alias1\",\"method\":\"sign\",\"params\":[\"68656c6c6f\",{\"algorithm\":\"ed25519\",\"index\":0}]}");
+    check("sign with algorithm=ed25519 returns result",
           resp_has(resp, "\"result\""));
-    check("sign_data alias has signature",
+    check("sign has signature",
           resp_has(resp, "signature"));
     free(resp);
 
-    /* ---- Old verb alias: ssh_sign with algorithm=ed25519 ---- */
+    /* ---- Verb: sign (ssh) with algorithm=ed25519 ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
-        "{\"id\":\"alias2\",\"method\":\"ssh_sign\",\"params\":[\"68656c6c6f\",{\"algorithm\":\"ed25519\",\"index\":0}]}");
-    check("ssh_sign alias with algorithm=ed25519 returns result",
+        "{\"id\":\"alias2\",\"method\":\"sign\",\"params\":[\"68656c6c6f\",{\"algorithm\":\"ed25519\",\"index\":0}]}");
+    check("sign with algorithm=ed25519 returns result",
           resp_has(resp, "\"result\""));
     free(resp);
 
-    /* ---- Old verb alias: kem_encapsulate with algorithm=ml-kem-768 ---- */
+    /* ---- Verb: encapsulate with algorithm=ml-kem-768 ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
         "{\"id\":\"gpk5\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"ml-kem-768\",\"index\":1}]}");
     pub_hex = extract_result_field(resp, "public_key");
     free(resp);
     if (pub_hex) {
         snprintf(request, sizeof(request),
-            "{\"id\":\"alias3\",\"method\":\"kem_encapsulate\",\"params\":[\"%s\",{\"algorithm\":\"ml-kem-768\"}]}",
+            "{\"id\":\"alias3\",\"method\":\"encapsulate\",\"params\":[\"%s\",{\"algorithm\":\"ml-kem-768\"}]}",
             pub_hex);
         resp = dispatcher_handle_request(&g_dispatcher, request);
-        check("kem_encapsulate alias with algorithm=ml-kem-768 returns result",
+        check("encapsulate with algorithm=ml-kem-768 returns result",
               resp_has(resp, "\"result\""));
-        check("kem_encapsulate alias has ciphertext",
+        check("encapsulate has ciphertext",
               resp_has(resp, "ciphertext"));
         free(resp);
         free(pub_hex);
     }
 
-    /* ---- Backward compat: sign_event with role still works ---- */
+    /* ---- nostr_sign_event with role still works ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
-        "{\"id\":\"bc1\",\"method\":\"sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello\\\",\\\"tags\\\":[]}\",{\"role\":\"main\"}]}");
-    check("sign_event with role=main (backward compat) returns signed event",
+        "{\"id\":\"bc1\",\"method\":\"nostr_sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello\\\",\\\"tags\\\":[]}\",{\"role\":\"main\"}]}");
+    check("nostr_sign_event with role=main returns signed event",
           resp_has(resp, "pubkey") && resp_has(resp, "sig"));
     free(resp);
 
-    /* ---- Backward compat: get_public_key with role still works ---- */
+    /* ---- nostr_get_public_key with role still works ---- */
     resp = dispatcher_handle_request(&g_dispatcher,
-        "{\"id\":\"bc2\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"main\"}]}");
-    check("get_public_key with role=main (backward compat) returns hex",
+        "{\"id\":\"bc2\",\"method\":\"nostr_get_public_key\",\"params\":[{\"role\":\"main\"}]}");
+    check("nostr_get_public_key with role=main returns hex",
           resp_has(resp, "\"result\""));
     free(resp);
 
@@ -682,6 +687,96 @@ int main(void) {
         check("policy_check_algorithm: wrong caller -> NO_MATCH", rc == POLICY_NO_MATCH);
     }
 
+    /* ---- derive: HMAC-SHA256(privkey, data) — secp256k1 ---- */
+    /* Successful call returns a 64-hex digest. */
+    resp = dispatcher_handle_request(&g_dispatcher,
+        "{\"id\":\"dv1\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+    check("derive secp256k1 returns result", resp_has(resp, "\"result\""));
+    check("derive secp256k1 has digest field", resp_has(resp, "digest"));
+    check("derive secp256k1 has algorithm secp256k1", resp_has(resp, "secp256k1"));
+    {
+        char *digest_hex = extract_result_field(resp, "digest");
+        check("derive secp256k1 digest is 64 hex chars",
+              digest_hex != NULL && strlen(digest_hex) == 64);
+        free(digest_hex);
+    }
+    free(resp);
+
+    /* Determinism: same input -> same digest. */
+    resp = dispatcher_handle_request(&g_dispatcher,
+        "{\"id\":\"dv2\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+    {
+        char *digest2 = extract_result_field(resp, "digest");
+        /* Re-run first call to compare (deterministic). */
+        char *resp_a = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dv1b\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+        char *digest_a = extract_result_field(resp_a, "digest");
+        check("derive determinism: same input -> same digest",
+              digest2 != NULL && digest_a != NULL && strcmp(digest2, digest_a) == 0);
+        free(digest2); free(digest_a); free(resp_a);
+    }
+    free(resp);
+
+    /* Opaqueness: different inputs -> different digests. */
+    {
+        char *resp_b = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dv3\",\"method\":\"derive\",\"params\":[\"other-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+        char *resp_c = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dv1c\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+        char *dig_b = extract_result_field(resp_b, "digest");
+        char *dig_c = extract_result_field(resp_c, "digest");
+        check("derive opaqueness: different inputs -> different digests",
+              dig_b != NULL && dig_c != NULL && strcmp(dig_b, dig_c) != 0);
+        free(dig_b); free(dig_c); free(resp_b); free(resp_c);
+    }
+
+    /* Cross-check against nostr_hmac_sha256 with the derived private key. */
+    {
+        const unsigned char *priv = crypto_get_private_key(&g_key_store, 0);
+        unsigned char ref_mac[32];
+        char ref_hex[65];
+        char *resp_ref = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dvref\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+        char *got_hex = extract_result_field(resp_ref, "digest");
+        if (priv != NULL && nostr_hmac_sha256(priv, 32,
+                (const unsigned char *)"test-data", strlen("test-data"),
+                ref_mac) == 0) {
+            nostr_bytes_to_hex(ref_mac, 32, ref_hex);
+            check("derive matches reference HMAC-SHA256(privkey, data)",
+                  got_hex != NULL && strcmp(got_hex, ref_hex) == 0);
+        } else {
+            check("derive reference HMAC computation available", 0);
+        }
+        free(got_hex); free(resp_ref);
+    }
+
+    /* index is required: omitting it returns missing_index. */
+    resp = dispatcher_handle_request(&g_dispatcher,
+        "{\"id\":\"dv4\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\"}]}");
+    check("derive without index returns missing_index",
+          resp_has(resp, "missing_index"));
+    free(resp);
+
+    /* Non-secp256k1 algorithm is rejected. */
+    resp = dispatcher_handle_request(&g_dispatcher,
+        "{\"id\":\"dv5\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"ed25519\",\"index\":0}]}");
+    check("derive ed25519 returns algorithm error",
+          resp_has(resp, "algorithm_not_supported_for_verb") || resp_has(resp, "\"code\":1010"));
+    free(resp);
+
+    /* Different index -> different digest (different privkey). */
+    {
+        char *r0 = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dvi0\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":0}]}");
+        char *r1 = dispatcher_handle_request(&g_dispatcher,
+            "{\"id\":\"dvi1\",\"method\":\"derive\",\"params\":[\"test-data\",{\"algorithm\":\"secp256k1\",\"index\":1}]}");
+        char *d0 = extract_result_field(r0, "digest");
+        char *d1 = extract_result_field(r1, "digest");
+        check("derive different index -> different digest",
+              d0 != NULL && d1 != NULL && strcmp(d0, d1) != 0);
+        free(d0); free(d1); free(r0); free(r1);
+    }
+
     /* ---- Cleanup ---- */
     crypto_wipe(&g_key_store);
     alg_key_cache_wipe(&g_alg_key_cache);

tests/test_auth_envelope.c

@@ -110,7 +110,7 @@ int main(void) {
     check_condition("nostr_crypto_init", nostr_crypto_init() == 0);
     auth_nonce_cache_init(&cache);
 
-    req = make_request_json(privkey, "req-1", "sign_event", (int)time(NULL));
+    req = make_request_json(privkey, "req-1", "nostr_sign_event", (int)time(NULL));
     check_condition("build valid request", req != NULL);
     if (req != NULL) {
         check_condition("valid auth envelope accepted",
@@ -150,7 +150,7 @@ int main(void) {
         check_condition("parse second request", root != NULL);
         method_item = (root != NULL) ? cJSON_GetObjectItemCaseSensitive(root, "method") : NULL;
         if (method_item != NULL) {
-            cJSON_SetValuestring(method_item, "sign_event");
+            cJSON_SetValuestring(method_item, "nostr_sign_event");
         }
         tampered = (root != NULL) ? cJSON_PrintUnformatted(root) : NULL;
         cJSON_Delete(root);
@@ -172,7 +172,7 @@ int main(void) {
         free(req);
     }
 
-    req = make_request_json(privkey, "req-3", "sign_event", (int)time(NULL));
+    req = make_request_json(privkey, "req-3", "nostr_sign_event", (int)time(NULL));
     check_condition("build replay request", req != NULL);
     if (req != NULL) {
         int first_ok = auth_envelope_verify_request(req,
@@ -198,7 +198,7 @@ int main(void) {
         free(req);
     }
 
-    req = make_request_json(privkey, "req-4", "sign_event", (int)time(NULL) - 1000);
+    req = make_request_json(privkey, "req-4", "nostr_sign_event", (int)time(NULL) - 1000);
     check_condition("build stale request", req != NULL);
     if (req != NULL) {
         check_condition("stale request rejected",

tests/test_dispatcher.c

@@ -211,6 +211,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -220,22 +221,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -813,51 +816,51 @@ int main(void) {
         }
     }
 
-    /* 1. Valid get_public_key no selector -> default main, real pubkey */
+    /* 1. Valid nostr_get_public_key no selector -> default main, real pubkey */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[\"\"]}");
-    check_condition("get_public_key default role returns derived hex",
+        "{\"id\":\"1\",\"method\":\"nostr_get_public_key\",\"params\":[\"\"]}");
+    check_condition("nostr_get_public_key default role returns derived hex",
         response_has(resp, "\"id\":\"1\"") && !response_has(resp, "not_yet_derived") && response_has(resp, "\"result\":\""));
     free(resp);
 
-    /* 2. sign_event with role main */
+    /* 2. nostr_sign_event with role main */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"2\",\"method\":\"sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello\\\",\\\"tags\\\":[]}\",{\"role\":\"main\"}]}");
-    check_condition("sign_event with role=main returns signed event",
+        "{\"id\":\"2\",\"method\":\"nostr_sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello\\\",\\\"tags\\\":[]}\",{\"role\":\"main\"}]}");
+    check_condition("nostr_sign_event with role=main returns signed event",
         response_has(resp, "\"id\":\"2\"") && response_has(resp, "pubkey") && response_has(resp, "sig") && response_has(resp, "created_at"));
     free(resp);
 
-    /* 3. sign_event with nostr_index 0 */
+    /* 3. nostr_sign_event with nostr_index 0 */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"3\",\"method\":\"sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello2\\\",\\\"tags\\\":[]}\",{\"nostr_index\":0}]}");
-    check_condition("sign_event with nostr_index=0 returns signed event",
+        "{\"id\":\"3\",\"method\":\"nostr_sign_event\",\"params\":[\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello2\\\",\\\"tags\\\":[]}\",{\"nostr_index\":0}]}");
+    check_condition("nostr_sign_event with nostr_index=0 returns signed event",
         response_has(resp, "\"id\":\"3\"") && response_has(resp, "pubkey") && response_has(resp, "sig") && response_has(resp, "created_at"));
     free(resp);
 
     /* 4. ambiguous selector role + nostr_index */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"4\",\"method\":\"sign_event\",\"params\":[\"{}\",{\"role\":\"main\",\"nostr_index\":0}]}");
+        "{\"id\":\"4\",\"method\":\"nostr_sign_event\",\"params\":[\"{}\",{\"role\":\"main\",\"nostr_index\":0}]}");
     check_condition("ambiguous selector returns 1001",
         response_has(resp, "\"id\":\"4\"") && response_has(resp, "\"code\":1001"));
     free(resp);
 
     /* 5. unknown role */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"5\",\"method\":\"sign_event\",\"params\":[\"{}\",{\"role\":\"nonexistent\"}]}");
+        "{\"id\":\"5\",\"method\":\"nostr_sign_event\",\"params\":[\"{}\",{\"role\":\"nonexistent\"}]}");
     check_condition("unknown role returns 1002 with unknown_role",
         response_has(resp, "\"id\":\"5\"") && response_has(resp, "\"code\":1002") && response_has(resp, "unknown_role"));
     free(resp);
 
-    /* 6. purpose mismatch: sign_event against ssh role */
+    /* 6. purpose mismatch: nostr_sign_event against ssh role */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"6\",\"method\":\"sign_event\",\"params\":[\"{}\",{\"role\":\"ssh_key\"}]}");
+        "{\"id\":\"6\",\"method\":\"nostr_sign_event\",\"params\":[\"{}\",{\"role\":\"ssh_key\"}]}");
     check_condition("purpose mismatch returns 1004",
         response_has(resp, "\"id\":\"6\"") && response_has(resp, "\"code\":1004"));
     free(resp);
 
     /* 7. invalid JSON */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"7\",\"method\":\"sign_event\",\"params\":[\"{}\"]");
+        "{\"id\":\"7\",\"method\":\"nostr_sign_event\",\"params\":[\"{}\"]");
     check_condition("invalid JSON returns -32700",
         response_has(resp, "\"code\":-32700"));
     free(resp);
@@ -872,7 +875,7 @@ int main(void) {
     /* 9. mnemonic not loaded */
     mnemonic_unload(&mnemonic);
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"9\",\"method\":\"get_public_key\",\"params\":[\"\"]}");
+        "{\"id\":\"9\",\"method\":\"nostr_get_public_key\",\"params\":[\"\"]}");
     check_condition("mnemonic not loaded returns 1006",
         response_has(resp, "\"id\":\"9\"") && response_has(resp, "\"code\":1006"));
     free(resp);

tests/test_ed25519_x25519.c

@@ -9,11 +9,11 @@
  *   - x25519 ECDH roundtrip: two sides derive matching shared secret
  *   - x25519 determinism: same seed -> same keypair
  *   - SLIP-0010 derivation: deterministic seed from mnemonic+path
- *   - Integration: derive ed25519 key via crypto_derive_one, sign_data via
+ *   - Integration: derive ed25519 key via crypto_derive_one, sign via
  *     dispatcher, verify signature
- *   - Enforcement: sign_data allowed on ssh+ed25519, rejected on nostr+secp256k1
- *   - Enforcement: ssh_sign allowed on ssh+ed25519
- *   - Enforcement: kem_encapsulate/decapsulate rejected on ssh/ed25519
+ *   - Enforcement: sign allowed on ssh+ed25519, rejected on nostr+secp256k1
+ *   - Enforcement: sign allowed on ssh+ed25519
+ *   - Enforcement: encapsulate/decapsulate rejected on ssh/ed25519
  */
 /* NSIGNER_HEADERLESS_DECLS_BEGIN */
 #include <stddef.h>
@@ -150,19 +150,22 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_PURPOSE      -1
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
+#define ENFORCE_ERR_ALGORITHM    -4
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_SIGN                 "sign"
+#define VERB_VERIFY               "verify"
+#define VERB_ENCAPSULATE          "encapsulate"
+#define VERB_DECAPSULATE          "decapsulate"
+#define VERB_DERIVE_SHARED        "derive_shared_secret"
+#define VERB_DERIVE           "derive"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -692,7 +695,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: sign_data via dispatcher ---- */
+    /* ---- Integration: sign via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t ssh_role;
@@ -717,27 +720,27 @@ int main(void) {
 
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &key_store, &g_alg_key_cache);
 
-        /* sign_data request */
+        /* sign request */
         snprintf(request, sizeof(request),
-                 "{\"id\":\"test1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"ssh_main\"}]}",
+                 "{\"id\":\"test1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"ed25519\",\"index\":0}]}",
                  msg_hex);
         resp = dispatcher_handle_request(&dispatcher, request);
-        check_condition("sign_data via dispatcher returns result",
+        check_condition("sign via dispatcher returns result",
                         resp != NULL && response_has(resp, "\"result\""));
-        check_condition("sign_data result contains signature",
+        check_condition("sign result contains signature",
                         resp != NULL && response_has(resp, "signature"));
-        check_condition("sign_data result contains algorithm ed25519",
+        check_condition("sign result contains algorithm ed25519",
                         resp != NULL && response_has(resp, "ed25519"));
         free(resp);
 
-        /* ssh_sign request */
+        /* sign request */
         snprintf(request, sizeof(request),
-                 "{\"id\":\"test2\",\"method\":\"ssh_sign\",\"params\":[\"%s\",{\"role\":\"ssh_main\"}]}",
+                 "{\"id\":\"test2\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"ed25519\",\"index\":0}]}",
                  msg_hex);
         resp = dispatcher_handle_request(&dispatcher, request);
-        check_condition("ssh_sign via dispatcher returns result",
+        check_condition("sign via dispatcher returns result",
                         resp != NULL && response_has(resp, "\"result\""));
-        check_condition("ssh_sign result contains signature",
+        check_condition("sign result contains signature",
                         resp != NULL && response_has(resp, "signature"));
         free(resp);
 
@@ -745,38 +748,39 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Enforcement: sign_data on ssh+ed25519 ---- */
+    /* ---- Enforcement: sign on ssh+ed25519 ---- */
     {
         role_entry_t ssh_ed = make_ssh_ed25519_entry("ssh", 0);
         role_entry_t nostr_secp = make_nostr_secp_entry("nostr", 0);
         role_entry_t pq_kem = make_pq_kem_entry("kem", 0);
 
-        check_condition("enforce sign_data + ssh/ed25519 -> OK",
-                        enforce_verb_role(VERB_SIGN_DATA, &ssh_ed) == ENFORCE_OK);
+        /* sign/verify are algorithm-based now: checked via enforce_verb_algorithm(). */
+        check_condition("enforce sign + ed25519 -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_ED25519) == ENFORCE_OK);
 
-        check_condition("enforce sign_data + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_SIGN_DATA, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce sign + secp256k1 -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
 
-        check_condition("enforce ssh_sign + ssh/ed25519 -> OK",
-                        enforce_verb_role(VERB_SSH_SIGN, &ssh_ed) == ENFORCE_OK);
+        check_condition("enforce verify + ed25519 -> OK",
+                        enforce_verb_algorithm(VERB_VERIFY, CRYPTO_ALG_ED25519) == ENFORCE_OK);
 
-        check_condition("enforce ssh_sign + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_SSH_SIGN, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce sign + ml-kem-768 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_ML_KEM_768) == ENFORCE_ERR_ALGORITHM);
 
-        check_condition("enforce sign_event + ssh/ed25519 -> PURPOSE err",
-                        enforce_verb_role(VERB_SIGN_EVENT, &ssh_ed) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce nostr_sign_event + ssh/ed25519 -> PURPOSE err",
+                        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &ssh_ed) == ENFORCE_ERR_PURPOSE);
 
-        check_condition("enforce kem_encapsulate + pq-kem/ml-kem-768 -> OK",
-                        enforce_verb_role(VERB_KEM_ENCAPS, &pq_kem) == ENFORCE_OK);
+        check_condition("enforce encapsulate + ml-kem-768 -> OK",
+                        enforce_verb_algorithm(VERB_ENCAPSULATE, CRYPTO_ALG_ML_KEM_768) == ENFORCE_OK);
 
-        check_condition("enforce kem_decapsulate + pq-kem/ml-kem-768 -> OK",
-                        enforce_verb_role(VERB_KEM_DECAPS, &pq_kem) == ENFORCE_OK);
+        check_condition("enforce decapsulate + ml-kem-768 -> OK",
+                        enforce_verb_algorithm(VERB_DECAPSULATE, CRYPTO_ALG_ML_KEM_768) == ENFORCE_OK);
 
-        check_condition("enforce kem_encapsulate + ssh/ed25519 -> PURPOSE err",
-                        enforce_verb_role(VERB_KEM_ENCAPS, &ssh_ed) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce encapsulate + ed25519 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_ENCAPSULATE, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
     }
 
-    /* ---- Dispatcher: kem_encapsulate with invalid pubkey length ---- */
+    /* ---- Dispatcher: encapsulate with invalid pubkey length ---- */
     {
         role_table_t table;
         role_entry_t kem_role;
@@ -784,7 +788,7 @@ int main(void) {
         key_store_t key_store;
         dispatcher_ctx_t dispatcher;
         char *resp;
-        const char *request = "{\"id\":\"k1\",\"method\":\"kem_encapsulate\",\"params\":[\"00\",{\"role\":\"kem_main\"}]}";
+        const char *request = "{\"id\":\"k1\",\"method\":\"encapsulate\",\"params\":[\"00\",{\"algorithm\":\"ml-kem-768\",\"index\":0}]}";
 
         role_table_init(&table);
         kem_role = make_pq_kem_entry("kem_main", 0);
@@ -798,11 +802,11 @@ int main(void) {
     alg_key_cache_init(&g_alg_key_cache);
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &key_store, &g_alg_key_cache);
 
-        /* kem_encapsulate is now implemented (Phase 5). With a too-short
+        /* encapsulate is now implemented (Phase 5). With a too-short
          * pubkey hex ("00" = 1 byte, but ML-KEM-768 needs 1184 bytes),
          * the dispatcher should return an invalid_pubkey_length error. */
         resp = dispatcher_handle_request(&dispatcher, request);
-        check_condition("kem_encapsulate with short pubkey returns error",
+        check_condition("encapsulate with short pubkey returns error",
                         resp != NULL && response_has(resp, "\"error\""));
         free(resp);
 
@@ -810,7 +814,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Dispatcher: verify_signature roundtrip ---- */
+    /* ---- Dispatcher: verify roundtrip ---- */
     {
         role_table_t table;
         role_entry_t ssh_role;
@@ -839,10 +843,10 @@ int main(void) {
 
         /* Sign */
         snprintf(sign_req, sizeof(sign_req),
-                 "{\"id\":\"s1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"ssh_main\"}]}",
+                 "{\"id\":\"s1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"ed25519\",\"index\":0}]}",
                  msg_hex);
         sign_resp = dispatcher_handle_request(&dispatcher, sign_req);
-        check_condition("verify roundtrip: sign_data succeeds", sign_resp != NULL);
+        check_condition("verify roundtrip: sign succeeds", sign_resp != NULL);
 
         /* Extract signature from result */
         if (sign_resp != NULL) {
@@ -867,28 +871,28 @@ int main(void) {
         /* Verify */
         if (sig_str != NULL) {
             snprintf(verify_req, sizeof(verify_req),
-                     "{\"id\":\"v1\",\"method\":\"verify_signature\",\"params\":[\"%s\",\"%s\",{\"role\":\"ssh_main\"}]}",
+                     "{\"id\":\"v1\",\"method\":\"verify\",\"params\":[\"%s\",\"%s\",{\"algorithm\":\"ed25519\",\"index\":0}]}",
                      msg_hex, sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature returns valid:true",
+            check_condition("verify returns valid:true",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "true"));
             free(verify_resp);
 
             /* Verify with wrong message */
             snprintf(verify_req, sizeof(verify_req),
-                     "{\"id\":\"v2\",\"method\":\"verify_signature\",\"params\":[\"00ff\",\"%s\",{\"role\":\"ssh_main\"}]}",
+                     "{\"id\":\"v2\",\"method\":\"verify\",\"params\":[\"00ff\",\"%s\",{\"algorithm\":\"ed25519\",\"index\":0}]}",
                      sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature wrong msg returns valid:false",
+            check_condition("verify wrong msg returns valid:false",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "false"));
             free(verify_resp);
 
             free((void *)sig_str);
         } else {
-            check_condition("verify_signature returns valid:true", 0);
-            check_condition("verify_signature wrong msg returns valid:false", 0);
+            check_condition("verify returns valid:true", 0);
+            check_condition("verify wrong msg returns valid:false", 0);
         }
 
         free(sign_resp);

tests/test_enforcement.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -739,43 +742,43 @@ int main(void) {
     role_entry_t age_x = make_role("age", "x25519");
 
     check_condition(
-        "sign_event + nostr/secp256k1 -> ENFORCE_OK",
-        enforce_verb_role(VERB_SIGN_EVENT, &nostr_secp) == ENFORCE_OK
+        "nostr_sign_event + nostr/secp256k1 -> ENFORCE_OK",
+        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &nostr_secp) == ENFORCE_OK
     );
 
     check_condition(
-        "get_public_key + nostr/secp256k1 -> ENFORCE_OK",
-        enforce_verb_role(VERB_GET_PUBLIC_KEY, &nostr_secp) == ENFORCE_OK
+        "nostr_get_public_key + nostr/secp256k1 -> ENFORCE_OK",
+        enforce_verb_role(VERB_NOSTR_GET_PUBLIC_KEY, &nostr_secp) == ENFORCE_OK
     );
 
     check_condition(
-        "nip44_encrypt + nostr/secp256k1 -> ENFORCE_OK",
-        enforce_verb_role(VERB_NIP44_ENCRYPT, &nostr_secp) == ENFORCE_OK
+        "nostr_nip44_encrypt + nostr/secp256k1 -> ENFORCE_OK",
+        enforce_verb_role(VERB_NOSTR_NIP44_ENCRYPT, &nostr_secp) == ENFORCE_OK
     );
 
     check_condition(
-        "nip44_decrypt + nostr/secp256k1 -> ENFORCE_OK",
-        enforce_verb_role(VERB_NIP44_DECRYPT, &nostr_secp) == ENFORCE_OK
+        "nostr_nip44_decrypt + nostr/secp256k1 -> ENFORCE_OK",
+        enforce_verb_role(VERB_NOSTR_NIP44_DECRYPT, &nostr_secp) == ENFORCE_OK
     );
 
     check_condition(
-        "nip04_encrypt + nostr/secp256k1 -> ENFORCE_OK",
-        enforce_verb_role(VERB_NIP04_ENCRYPT, &nostr_secp) == ENFORCE_OK
+        "nostr_nip04_encrypt + nostr/secp256k1 -> ENFORCE_OK",
+        enforce_verb_role(VERB_NOSTR_NIP04_ENCRYPT, &nostr_secp) == ENFORCE_OK
     );
 
     check_condition(
-        "sign_event + bitcoin/secp256k1 -> ENFORCE_ERR_PURPOSE",
-        enforce_verb_role(VERB_SIGN_EVENT, &bitcoin_secp) == ENFORCE_ERR_PURPOSE
+        "nostr_sign_event + bitcoin/secp256k1 -> ENFORCE_ERR_PURPOSE",
+        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &bitcoin_secp) == ENFORCE_ERR_PURPOSE
     );
 
     check_condition(
-        "sign_event + nostr/ed25519 -> ENFORCE_ERR_CURVE",
-        enforce_verb_role(VERB_SIGN_EVENT, &nostr_ed) == ENFORCE_ERR_CURVE
+        "nostr_sign_event + nostr/ed25519 -> ENFORCE_ERR_CURVE",
+        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &nostr_ed) == ENFORCE_ERR_CURVE
     );
 
     check_condition(
-        "sign_event + ssh/ed25519 -> ENFORCE_ERR_PURPOSE",
-        enforce_verb_role(VERB_SIGN_EVENT, &ssh_ed) == ENFORCE_ERR_PURPOSE
+        "nostr_sign_event + ssh/ed25519 -> ENFORCE_ERR_PURPOSE",
+        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &ssh_ed) == ENFORCE_ERR_PURPOSE
     );
 
     check_condition(
@@ -784,8 +787,8 @@ int main(void) {
     );
 
     check_condition(
-        "nip44_encrypt + age/x25519 -> ENFORCE_ERR_PURPOSE",
-        enforce_verb_role(VERB_NIP44_ENCRYPT, &age_x) == ENFORCE_ERR_PURPOSE
+        "nostr_nip44_encrypt + age/x25519 -> ENFORCE_ERR_PURPOSE",
+        enforce_verb_role(VERB_NOSTR_NIP44_ENCRYPT, &age_x) == ENFORCE_ERR_PURPOSE
     );
 
     printf("%d/10 tests passed\n", g_passes);

tests/test_integration.c

@@ -210,6 +210,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -219,22 +220,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -1001,13 +1004,13 @@ int main(void) {
         nsigner_client_free(c);
         c = NULL;
 
-        /* sign_event (fresh connection) */
+        /* nostr_sign_event (fresh connection) */
         t = nsigner_transport_open_unix(SOCKET_NAME_A, 5000);
         if (t != NULL) {
             c = nsigner_client_new(t);
             if (c == NULL) {
                 t->close(t);
-                check_condition("connect signer socket for sign_event", 0);
+                check_condition("connect signer socket for nostr_sign_event", 0);
             } else {
                 params = cJSON_CreateArray();
                 if (params != NULL) {
@@ -1018,10 +1021,10 @@ int main(void) {
                         cJSON_AddItemToArray(params, opts);
                         opts = NULL;
                     }
-                    if (nsigner_client_call(c, "sign_event", params, &se_result) == NOSTR_SUCCESS) {
-                        check_condition("sign_event has result", se_result != NULL);
+                    if (nsigner_client_call(c, "nostr_sign_event", params, &se_result) == NOSTR_SUCCESS) {
+                        check_condition("nostr_sign_event has result", se_result != NULL);
                     } else {
-                        check_condition("sign_event request roundtrip", 0);
+                        check_condition("nostr_sign_event request roundtrip", 0);
                     }
                     params = NULL; /* nsigner_client_call took ownership */
                     cJSON_Delete(se_result);
@@ -1029,7 +1032,7 @@ int main(void) {
                 }
             }
         } else {
-            check_condition("connect signer socket for sign_event", 0);
+            check_condition("connect signer socket for nostr_sign_event", 0);
         }
 
         cJSON_Delete(params);
@@ -1052,7 +1055,7 @@ int main(void) {
             if (p) { p += 10; strncpy(pub_a, p, 64); pub_a[64]='\0'; }
             check_condition("single-instance public key request", pub_a[0] != '\0');
 
-            snprintf(req, sizeof(req), "{\"id\":\"5\",\"method\":\"nip04_encrypt\",\"params\":[\"%s\",\"hello_nip04\"]}", pub_a);
+            snprintf(req, sizeof(req), "{\"id\":\"5\",\"method\":\"nostr_nip04_encrypt\",\"params\":[\"%s\",\"hello_nip04\"]}", pub_a);
             free(resp_a); resp_a = NULL;
             if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                 p = strstr(resp_a, "\"result\":\"");
@@ -1062,7 +1065,7 @@ int main(void) {
                     while (p[i] && p[i] != '\"' && i < sizeof(cipher)-1) { cipher[i]=p[i]; i++; }
                     cipher[i]='\0';
                 }
-                snprintf(req, sizeof(req), "{\"id\":\"6\",\"method\":\"nip04_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
+                snprintf(req, sizeof(req), "{\"id\":\"6\",\"method\":\"nostr_nip04_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
                 free(resp_a); resp_a = NULL;
                 if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                     check_condition("nip04 round-trip plaintext recovered", strstr(resp_a, "hello_nip04") != NULL);
@@ -1074,7 +1077,7 @@ int main(void) {
             }
 
             memset(cipher, 0, sizeof(cipher));
-            snprintf(req, sizeof(req), "{\"id\":\"7\",\"method\":\"nip44_encrypt\",\"params\":[\"%s\",\"hello_nip44\"]}", pub_a);
+            snprintf(req, sizeof(req), "{\"id\":\"7\",\"method\":\"nostr_nip44_encrypt\",\"params\":[\"%s\",\"hello_nip44\"]}", pub_a);
             free(resp_a); resp_a = NULL;
             if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                 p = strstr(resp_a, "\"result\":\"");
@@ -1084,7 +1087,7 @@ int main(void) {
                     while (p[i] && p[i] != '\"' && i < sizeof(cipher)-1) { cipher[i]=p[i]; i++; }
                     cipher[i]='\0';
                 }
-                snprintf(req, sizeof(req), "{\"id\":\"8\",\"method\":\"nip44_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
+                snprintf(req, sizeof(req), "{\"id\":\"8\",\"method\":\"nostr_nip44_decrypt\",\"params\":[\"%s\",\"%s\"]}", pub_a, cipher);
                 free(resp_a); resp_a = NULL;
                 if (request_roundtrip_to(SOCKET_NAME_A, req, &resp_a) == 0) {
                     check_condition("nip44 round-trip plaintext recovered", strstr(resp_a, "hello_nip44") != NULL);

tests/test_mine_event.c

@@ -1,4 +1,4 @@
-/* Test for mine_event verb (NIP-13 Proof-of-Work) */
+/* Test for nostr_mine_event verb (NIP-13 Proof-of-Work) */
 /* NSIGNER_HEADERLESS_DECLS_BEGIN */
 #include <stddef.h>
 #include <stdint.h>
@@ -126,18 +126,14 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -497,7 +493,7 @@ static int response_has(const char *response, const char *needle) {
     return (response != NULL && needle != NULL && strstr(response, needle) != NULL);
 }
 
-/* Parse a dispatcher response and extract the result object (for mine_event).
+/* Parse a dispatcher response and extract the result object (for nostr_mine_event).
  * Returns a newly-allocated cJSON result object, or NULL on failure.
  * Caller must delete the returned object. */
 static cJSON *extract_result_object(const char *response) {
@@ -580,67 +576,67 @@ int main(void) {
     derived = crypto_derive_all(&key_store, &table, &mnemonic);
     check_condition("crypto_derive_all derives at least one key", derived >= 1);
 
-    /* 1. mine_event with low difficulty (2) and short timeout (5 sec) — should reach target */
+    /* 1. nostr_mine_event with low difficulty (2) and short timeout (5 sec) — should reach target */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"1\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"1\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"{\\\"kind\\\":1,\\\"content\\\":\\\"hello pow\\\",\\\"tags\\\":[]}\","
         "{\"difficulty\":2,\"threads\":2,\"timeout_sec\":5}]}");
-    check_condition("mine_event low difficulty returns result object",
+    check_condition("nostr_mine_event low difficulty returns result object",
         response_has(resp, "\"id\":\"1\"") && response_has(resp, "\"result\"") && response_has(resp, "achieved_difficulty"));
-    check_condition("mine_event low difficulty returns signed event with nonce tag",
+    check_condition("nostr_mine_event low difficulty returns signed event with nonce tag",
         response_has(resp, "nonce") && response_has(resp, "sig") && response_has(resp, "pubkey"));
-    check_condition("mine_event low difficulty target_reached is true",
+    check_condition("nostr_mine_event low difficulty target_reached is true",
         check_target_reached(resp, 1));
     free(resp);
 
-    /* 2. mine_event with high difficulty (30) and short timeout (2 sec) — should NOT reach target */
+    /* 2. nostr_mine_event with high difficulty (30) and short timeout (2 sec) — should NOT reach target */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"2\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"2\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"{\\\"kind\\\":1,\\\"content\\\":\\\"hard pow\\\",\\\"tags\\\":[]}\","
         "{\"difficulty\":30,\"threads\":4,\"timeout_sec\":2}]}");
-    check_condition("mine_event high difficulty returns result object",
+    check_condition("nostr_mine_event high difficulty returns result object",
         response_has(resp, "\"id\":\"2\"") && response_has(resp, "\"result\"") && response_has(resp, "achieved_difficulty"));
-    check_condition("mine_event high difficulty target_reached is false",
+    check_condition("nostr_mine_event high difficulty target_reached is false",
         check_target_reached(resp, 0));
-    check_condition("mine_event high difficulty still returns a signed event",
+    check_condition("nostr_mine_event high difficulty still returns a signed event",
         response_has(resp, "nonce") && response_has(resp, "sig"));
     free(resp);
 
-    /* 3. mine_event with only timeout (no difficulty) — should mine for full duration */
+    /* 3. nostr_mine_event with only timeout (no difficulty) — should mine for full duration */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"3\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"3\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"{\\\"kind\\\":1,\\\"content\\\":\\\"timeout only\\\",\\\"tags\\\":[]}\","
         "{\"threads\":2,\"timeout_sec\":2}]}");
-    check_condition("mine_event timeout-only returns result",
+    check_condition("nostr_mine_event timeout-only returns result",
         response_has(resp, "\"id\":\"3\"") && response_has(resp, "\"result\"") && response_has(resp, "achieved_difficulty"));
-    check_condition("mine_event timeout-only target_reached is false (no target set)",
+    check_condition("nostr_mine_event timeout-only target_reached is false (no target set)",
         check_target_reached(resp, 0));
     free(resp);
 
-    /* 4. mine_event with neither difficulty nor timeout — should error */
+    /* 4. nostr_mine_event with neither difficulty nor timeout — should error */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"4\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"4\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"{\\\"kind\\\":1,\\\"content\\\":\\\"no params\\\",\\\"tags\\\":[]}\","
         "{\"threads\":2}]}");
-    check_condition("mine_event with no termination condition returns 1007",
+    check_condition("nostr_mine_event with no termination condition returns 1007",
         response_has(resp, "\"id\":\"4\"") && response_has(resp, "\"code\":1007") && response_has(resp, "no_termination_condition"));
     free(resp);
 
-    /* 5. mine_event with only difficulty (no timeout) — should use safety timeout and reach low target */
+    /* 5. nostr_mine_event with only difficulty (no timeout) — should use safety timeout and reach low target */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"5\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"5\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"{\\\"kind\\\":1,\\\"content\\\":\\\"difficulty only\\\",\\\"tags\\\":[]}\","
         "{\"difficulty\":1,\"threads\":2}]}");
-    check_condition("mine_event difficulty-only returns result and reaches target",
+    check_condition("nostr_mine_event difficulty-only returns result and reaches target",
         response_has(resp, "\"id\":\"5\"") && response_has(resp, "\"result\"") && check_target_reached(resp, 1));
     free(resp);
 
-    /* 6. mine_event with invalid event JSON */
+    /* 6. nostr_mine_event with invalid event JSON */
     resp = dispatcher_handle_request(&dispatcher,
-        "{\"id\":\"6\",\"method\":\"mine_event\",\"params\":["
+        "{\"id\":\"6\",\"method\":\"nostr_mine_event\",\"params\":["
         "\"not valid json\","
         "{\"difficulty\":1,\"timeout_sec\":2}]}");
-    check_condition("mine_event with invalid event returns error",
+    check_condition("nostr_mine_event with invalid event returns error",
         response_has(resp, "\"id\":\"6\"") && (response_has(resp, "\"code\":1008") || response_has(resp, "\"code\":-32602")));
     free(resp);
 
@@ -651,7 +647,7 @@ int main(void) {
         int pow_diff;
 
         resp = dispatcher_handle_request(&dispatcher,
-            "{\"id\":\"7\",\"method\":\"mine_event\",\"params\":["
+            "{\"id\":\"7\",\"method\":\"nostr_mine_event\",\"params\":["
             "\"{\\\"kind\\\":1,\\\"content\\\":\\\"verify pow\\\",\\\"tags\\\":[]}\","
             "{\"difficulty\":4,\"threads\":4,\"timeout_sec\":5}]}");
 

tests/test_ml_dsa_65.c

@@ -8,8 +8,8 @@
  *   - ML-DSA-65 sign/verify with wrong key: verify fails
  *   - DRBG determinism: same seed -> same randombytes output
  *   - Integration: derive ML-DSA-65 key from mnemonic via crypto_derive_one,
- *     sign data via sign_data verb through dispatcher, verify signature
- *   - Enforcement: sign_data allowed on pq-sig+ml-dsa-65
+ *     sign data via sign verb through dispatcher, verify signature
+ *   - Enforcement: sign allowed on pq-sig+ml-dsa-65
  */
 /* NSIGNER_HEADERLESS_DECLS_BEGIN */
 #include <stddef.h>
@@ -142,19 +142,22 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_PURPOSE      -1
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
+#define ENFORCE_ERR_ALGORITHM   -4
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_SIGN                 "sign"
+#define VERB_VERIFY               "verify"
+#define VERB_ENCAPSULATE          "encapsulate"
+#define VERB_DECAPSULATE          "decapsulate"
+#define VERB_DERIVE_SHARED        "derive_shared_secret"
+#define VERB_DERIVE           "derive"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -682,7 +685,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: sign_data via dispatcher ---- */
+    /* ---- Integration: sign via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t pq_role;
@@ -705,16 +708,16 @@ int main(void) {
 
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &g_key_store, &g_alg_key_cache);
 
-        /* sign_data request */
+        /* sign request */
         snprintf(request, sizeof(request),
-                 "{\"id\":\"test1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"pq_main\"}]}",
+                 "{\"id\":\"test1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"ml-dsa-65\",\"index\":0}]}",
                  msg_hex);
         resp = dispatcher_handle_request(&dispatcher, request);
-        check_condition("sign_data via dispatcher returns result",
+        check_condition("sign via dispatcher returns result",
                         resp != NULL && response_has(resp, "\"result\""));
-        check_condition("sign_data result contains signature",
+        check_condition("sign result contains signature",
                         resp != NULL && response_has(resp, "signature"));
-        check_condition("sign_data result contains algorithm ml-dsa-65",
+        check_condition("sign result contains algorithm ml-dsa-65",
                         resp != NULL && response_has(resp, "ml-dsa-65"));
         free(resp);
 
@@ -722,7 +725,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: verify_signature roundtrip via dispatcher ---- */
+    /* ---- Integration: verify roundtrip via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t pq_role;
@@ -749,10 +752,10 @@ int main(void) {
 
         /* Sign */
         snprintf(sign_req, sizeof(sign_req),
-                 "{\"id\":\"s1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"pq_main\"}]}",
+                 "{\"id\":\"s1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"ml-dsa-65\",\"index\":0}]}",
                  msg_hex);
         sign_resp = dispatcher_handle_request(&dispatcher, sign_req);
-        check_condition("verify roundtrip: sign_data succeeds", sign_resp != NULL);
+        check_condition("verify roundtrip: sign succeeds", sign_resp != NULL);
 
         /* Extract signature from result */
         if (sign_resp != NULL) {
@@ -777,28 +780,28 @@ int main(void) {
         /* Verify */
         if (sig_str != NULL) {
             snprintf(verify_req, sizeof(verify_req),
-                     "{\"id\":\"v1\",\"method\":\"verify_signature\",\"params\":[\"%s\",\"%s\",{\"role\":\"pq_main\"}]}",
+                     "{\"id\":\"v1\",\"method\":\"verify\",\"params\":[\"%s\",\"%s\",{\"algorithm\":\"ml-dsa-65\",\"index\":0}]}",
                      msg_hex, sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature returns valid:true",
+            check_condition("verify returns valid:true",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "true"));
             free(verify_resp);
 
             /* Verify with wrong message */
             snprintf(verify_req, sizeof(verify_req),
-                     "{\"id\":\"v2\",\"method\":\"verify_signature\",\"params\":[\"00ff\",\"%s\",{\"role\":\"pq_main\"}]}",
+                     "{\"id\":\"v2\",\"method\":\"verify\",\"params\":[\"00ff\",\"%s\",{\"algorithm\":\"ml-dsa-65\",\"index\":0}]}",
                      sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature wrong msg returns valid:false",
+            check_condition("verify wrong msg returns valid:false",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "false"));
             free(verify_resp);
 
             free((void *)sig_str);
         } else {
-            check_condition("verify_signature returns valid:true", 0);
-            check_condition("verify_signature wrong msg returns valid:false", 0);
+            check_condition("verify returns valid:true", 0);
+            check_condition("verify wrong msg returns valid:false", 0);
         }
 
         free(sign_resp);
@@ -806,22 +809,26 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Enforcement: sign_data on pq-sig+ml-dsa-65 ---- */
+    /* ---- Enforcement: sign on pq-sig+ml-dsa-65 ---- */
     {
         role_entry_t pq_sig = make_pq_sig_ml_dsa_65_entry("pq", 0);
         role_entry_t nostr_secp = make_nostr_secp_entry("nostr", 0);
 
-        check_condition("enforce sign_data + pq-sig/ml-dsa-65 -> OK",
-                        enforce_verb_role(VERB_SIGN_DATA, &pq_sig) == ENFORCE_OK);
+        /* sign/verify are algorithm-based now. */
+        check_condition("enforce sign + ml-dsa-65 -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_ML_DSA_65) == ENFORCE_OK);
 
-        check_condition("enforce sign_data + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_SIGN_DATA, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce sign + secp256k1 -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
 
-        check_condition("enforce verify_signature + pq-sig/ml-dsa-65 -> OK",
-                        enforce_verb_role(VERB_VERIFY_SIG, &pq_sig) == ENFORCE_OK);
+        check_condition("enforce verify + ml-dsa-65 -> OK",
+                        enforce_verb_algorithm(VERB_VERIFY, CRYPTO_ALG_ML_DSA_65) == ENFORCE_OK);
 
-        check_condition("enforce sign_event + pq-sig/ml-dsa-65 -> PURPOSE err",
-                        enforce_verb_role(VERB_SIGN_EVENT, &pq_sig) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce sign + ml-kem-768 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_ML_KEM_768) == ENFORCE_ERR_ALGORITHM);
+
+        check_condition("enforce nostr_sign_event + pq-sig/ml-dsa-65 -> PURPOSE err",
+                        enforce_verb_role(VERB_NOSTR_SIGN_EVENT, &pq_sig) == ENFORCE_ERR_PURPOSE);
     }
 
     /* Cleanup */

tests/test_ml_kem_768.c

@@ -8,7 +8,7 @@
  *   - Decaps with wrong ciphertext: different shared secret (implicit rejection)
  *   - Integration: derive ML-KEM-768 key from mnemonic, encaps via dispatcher,
  *     decaps via dispatcher, shared secrets match
- *   - Enforcement: kem_encapsulate/kem_decapsulate allowed on pq-kem+ml-kem-768
+ *   - Enforcement: encapsulate/decapsulate allowed on pq-kem+ml-kem-768
  */
 /* NSIGNER_HEADERLESS_DECLS_BEGIN */
 #include <stddef.h>
@@ -112,19 +112,22 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_PURPOSE -1
 #define ENFORCE_ERR_CURVE -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
+#define ENFORCE_ERR_ALGORITHM -4
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_SIGN                 "sign"
+#define VERB_VERIFY               "verify"
+#define VERB_ENCAPSULATE          "encapsulate"
+#define VERB_DECAPSULATE          "decapsulate"
+#define VERB_DERIVE_SHARED        "derive_shared_secret"
+#define VERB_DERIVE           "derive"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -521,7 +524,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: kem_encapsulate / kem_decapsulate via dispatcher ---- */
+    /* ---- Integration: encapsulate / decapsulate via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t pq_role;
@@ -552,18 +555,18 @@ int main(void) {
         check_condition("dispatcher integration: pubkey available", pub_hex != NULL);
 
         if (pub_hex != NULL && decaps_req != NULL) {
-            /* kem_encapsulate request */
+            /* encapsulate request */
             snprintf(encaps_req, sizeof(encaps_req),
-                     "{\"id\":\"e1\",\"method\":\"kem_encapsulate\",\"params\":[\"%s\",{\"role\":\"pq_kem\"}]}",
+                     "{\"id\":\"e1\",\"method\":\"encapsulate\",\"params\":[\"%s\",{\"algorithm\":\"ml-kem-768\",\"index\":0}]}",
                      pub_hex);
             encaps_resp = dispatcher_handle_request(&dispatcher, encaps_req);
-            check_condition("kem_encapsulate via dispatcher returns result",
+            check_condition("encapsulate via dispatcher returns result",
                             encaps_resp != NULL && response_has(encaps_resp, "\"result\""));
-            check_condition("kem_encapsulate result contains ciphertext",
+            check_condition("encapsulate result contains ciphertext",
                             encaps_resp != NULL && response_has(encaps_resp, "ciphertext"));
-            check_condition("kem_encapsulate result contains shared_secret",
+            check_condition("encapsulate result contains shared_secret",
                             encaps_resp != NULL && response_has(encaps_resp, "shared_secret"));
-            check_condition("kem_encapsulate result contains algorithm ml-kem-768",
+            check_condition("encapsulate result contains algorithm ml-kem-768",
                             encaps_resp != NULL && response_has(encaps_resp, "ml-kem-768"));
 
             /* Extract ciphertext and shared_secret from result */
@@ -584,18 +587,18 @@ int main(void) {
                     cJSON_Delete(encaps_json);
                 }
             }
-            check_condition("kem_encapsulate: extracted ciphertext hex", ct_str != NULL);
-            check_condition("kem_encapsulate: extracted shared_secret hex", ss_encaps_str != NULL);
+            check_condition("encapsulate: extracted ciphertext hex", ct_str != NULL);
+            check_condition("encapsulate: extracted shared_secret hex", ss_encaps_str != NULL);
 
-            /* kem_decapsulate request */
+            /* decapsulate request */
             if (ct_str != NULL) {
                 snprintf(decaps_req, 6000,
-                         "{\"id\":\"d1\",\"method\":\"kem_decapsulate\",\"params\":[\"%s\",{\"role\":\"pq_kem\"}]}",
+                         "{\"id\":\"d1\",\"method\":\"decapsulate\",\"params\":[\"%s\",{\"algorithm\":\"ml-kem-768\",\"index\":0}]}",
                          ct_str);
                 decaps_resp = dispatcher_handle_request(&dispatcher, decaps_req);
-                check_condition("kem_decapsulate via dispatcher returns result",
+                check_condition("decapsulate via dispatcher returns result",
                                 decaps_resp != NULL && response_has(decaps_resp, "\"result\""));
-                check_condition("kem_decapsulate result contains shared_secret",
+                check_condition("decapsulate result contains shared_secret",
                                 decaps_resp != NULL && response_has(decaps_resp, "shared_secret"));
 
                 /* Extract shared_secret from decaps result */
@@ -626,8 +629,8 @@ int main(void) {
                 free((void *)ss_decaps_str);
                 free(decaps_resp);
             } else {
-                check_condition("kem_decapsulate via dispatcher returns result", 0);
-                check_condition("kem_decapsulate result contains shared_secret", 0);
+                check_condition("decapsulate via dispatcher returns result", 0);
+                check_condition("decapsulate result contains shared_secret", 0);
                 check_condition("dispatcher encaps/decaps shared secrets match", 0);
             }
 
@@ -641,22 +644,23 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Enforcement: kem_encapsulate/kem_decapsulate on pq-kem+ml-kem-768 ---- */
+    /* ---- Enforcement: encapsulate/decapsulate on pq-kem+ml-kem-768 ---- */
     {
         role_entry_t pq_kem = make_pq_kem_ml_kem_768_entry("pqk", 0);
         role_entry_t nostr_secp = make_nostr_secp_entry("nostr", 0);
 
-        check_condition("enforce kem_encapsulate + pq-kem/ml-kem-768 -> OK",
-                        enforce_verb_role(VERB_KEM_ENCAPS, &pq_kem) == ENFORCE_OK);
+        /* encapsulate/decapsulate are algorithm-based now. */
+        check_condition("enforce encapsulate + ml-kem-768 -> OK",
+                        enforce_verb_algorithm(VERB_ENCAPSULATE, CRYPTO_ALG_ML_KEM_768) == ENFORCE_OK);
 
-        check_condition("enforce kem_encapsulate + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_KEM_ENCAPS, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce encapsulate + secp256k1 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_ENCAPSULATE, CRYPTO_ALG_SECP256K1) == ENFORCE_ERR_ALGORITHM);
 
-        check_condition("enforce kem_decapsulate + pq-kem/ml-kem-768 -> OK",
-                        enforce_verb_role(VERB_KEM_DECAPS, &pq_kem) == ENFORCE_OK);
+        check_condition("enforce decapsulate + ml-kem-768 -> OK",
+                        enforce_verb_algorithm(VERB_DECAPSULATE, CRYPTO_ALG_ML_KEM_768) == ENFORCE_OK);
 
-        check_condition("enforce kem_decapsulate + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_KEM_DECAPS, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce decapsulate + ed25519 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_DECAPSULATE, CRYPTO_ALG_ED25519) == ENFORCE_ERR_ALGORITHM);
     }
 
     /* ---- Cleanup ---- */

tests/test_mnemonic.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */

tests/test_policy.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */
@@ -801,10 +804,10 @@ int main(void) {
     check_condition("parse_preapprove_spec rejects non-numeric nostr_index", rc == -1);
 
     policy_init_default(&table, uid);
-    rc = policy_check(&table, same_uid, "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, same_uid, "nostr_sign_event", "main", "nostr", NULL);
     check_condition("policy_init_default prompts same uid", rc == POLICY_PROMPT);
 
-    rc = policy_check(&table, other_uid, "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, other_uid, "nostr_sign_event", "main", "nostr", NULL);
     check_condition("policy_init_default prompts different uid", rc == POLICY_PROMPT);
 
     /* Insert before catch-all: matching caller allowed, non-matching still prompted */
@@ -820,9 +823,9 @@ int main(void) {
         rc = policy_table_insert_before_last(&table, &grant);
         check_condition("policy_table_insert_before_last succeeds", rc == 0);
     }
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("insert_before_last matching caller returns POLICY_ALLOW", rc == POLICY_ALLOW);
-    rc = policy_check(&table, "uid:2000", "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:2000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("insert_before_last non-matching caller returns POLICY_PROMPT", rc == POLICY_PROMPT);
 
     /* Preapprove parse + insert: matching caller allowed, non-matching prompted */
@@ -831,70 +834,70 @@ int main(void) {
     check_condition("preapprove parse for policy insert succeeds", rc == 0);
     rc = policy_table_insert_before_last(&table, &parsed);
     check_condition("preapprove insert_before_last succeeds", rc == 0);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("preapprove allows matching caller+role", rc == POLICY_ALLOW);
-    rc = policy_check(&table, "uid:2000", "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:2000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("preapprove leaves non-matching caller at POLICY_PROMPT", rc == POLICY_PROMPT);
 
     /* Exact caller, verb, role, purpose + never => allow */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_NEVER);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("exact match returns POLICY_ALLOW", rc == POLICY_ALLOW);
 
     /* Wildcard caller + deny => deny */
     policy_table_init(&table);
-    add_single_entry(&table, "*", "sign_event", "main", "nostr", PROMPT_DENY);
-    rc = policy_check(&table, "uid:2000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "*", "nostr_sign_event", "main", "nostr", PROMPT_DENY);
+    rc = policy_check(&table, "uid:2000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("wildcard caller with deny returns POLICY_DENY", rc == POLICY_DENY);
 
     /* Caller no match => POLICY_NO_MATCH */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:9999", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_NEVER);
+    rc = policy_check(&table, "uid:9999", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("caller mismatch returns POLICY_NO_MATCH", rc == POLICY_NO_MATCH);
 
     /* Verb not in list => no match */
     policy_table_init(&table);
     add_single_entry(&table, "uid:1000", "get_public_key", "main", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("verb mismatch returns POLICY_NO_MATCH", rc == POLICY_NO_MATCH);
 
     /* Role not in list => no match */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "throwaway", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "throwaway", "nostr", PROMPT_NEVER);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("role mismatch returns POLICY_NO_MATCH", rc == POLICY_NO_MATCH);
 
     /* Purpose not in list => no match */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "bitcoin", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "bitcoin", PROMPT_NEVER);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("purpose mismatch returns POLICY_NO_MATCH", rc == POLICY_NO_MATCH);
 
     /* Empty verbs list means all verbs */
     policy_table_init(&table);
     add_single_entry(&table, "uid:1000", NULL, "main", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "nip44_encrypt", "main", "nostr", NULL);
+    rc = policy_check(&table, "uid:1000", "nostr_nip44_encrypt", "main", "nostr", NULL);
     check_condition("empty verbs list matches any verb", rc == POLICY_ALLOW);
 
     /* prompt=first_per_boot => POLICY_PROMPT */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_FIRST_PER_BOOT);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_FIRST_PER_BOOT);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("first_per_boot returns POLICY_PROMPT", rc == POLICY_PROMPT);
 
     /* prompt=every_request => POLICY_PROMPT */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_EVERY_REQUEST);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_EVERY_REQUEST);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("every_request returns POLICY_PROMPT", rc == POLICY_PROMPT);
 
     /* First matching entry wins */
     policy_table_init(&table);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_DENY);
-    add_single_entry(&table, "uid:1000", "sign_event", "main", "nostr", PROMPT_NEVER);
-    rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", NULL);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_DENY);
+    add_single_entry(&table, "uid:1000", "nostr_sign_event", "main", "nostr", PROMPT_NEVER);
+    rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", NULL);
     check_condition("first matching entry wins", rc == POLICY_DENY);
 
     /* Verify out_source for preapprove, session-grant, and default catch-all */
@@ -931,15 +934,15 @@ int main(void) {
         check_condition("source test default catch-all add", rc == 0);
 
         src = POLICY_SOURCE_DEFAULT;
-        rc = policy_check(&table, "uid:1000", "sign_event", "main", "nostr", &src);
+        rc = policy_check(&table, "uid:1000", "nostr_sign_event", "main", "nostr", &src);
         check_condition("policy_check reports preapprove source", rc == POLICY_ALLOW && src == POLICY_SOURCE_PREAPPROVE);
 
         src = POLICY_SOURCE_DEFAULT;
-        rc = policy_check(&table, "uid:1001", "sign_event", "main", "nostr", &src);
+        rc = policy_check(&table, "uid:1001", "nostr_sign_event", "main", "nostr", &src);
         check_condition("policy_check reports session-grant source", rc == POLICY_ALLOW && src == POLICY_SOURCE_SESSION_GRANT);
 
         src = POLICY_SOURCE_PREAPPROVE;
-        rc = policy_check(&table, "uid:9999", "sign_event", "main", "nostr", &src);
+        rc = policy_check(&table, "uid:9999", "nostr_sign_event", "main", "nostr", &src);
         check_condition("policy_check resets source for prompt/default", rc == POLICY_PROMPT && src == POLICY_SOURCE_DEFAULT);
     }
 

tests/test_pq_crypto.c

@@ -148,12 +148,13 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);

tests/test_pubkey_format.c

@@ -145,18 +145,14 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -539,16 +535,23 @@ int main(void) {
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &g_key_store, &g_alg_key_cache);
 
         resp = dispatcher_handle_request(&dispatcher,
-                                          "{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"main\"}]}");
+                                          "{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"secp256k1\",\"index\":0}]}");
         check_condition("secp256k1 get_public_key returns a response", resp != NULL);
 
+        /* Algorithm-based get_public_key always returns a structured object. */
         pr = parse_result(resp, &result_str, &result_obj);
-        check_condition("secp256k1 get_public_key result is a plain string (not object)",
-                        pr == 1 && result_str != NULL);
-        check_condition("secp256k1 plain hex result is 64 hex chars",
-                        result_str != NULL && strlen(result_str) == 64);
-        check_condition("secp256k1 plain hex result has no 'algorithm' field",
-                        !response_has(resp, "algorithm"));
+        check_condition("secp256k1 get_public_key result is a JSON object",
+                        pr == 2 && result_obj != NULL);
+        if (result_obj != NULL) {
+            cJSON *pk_item = cJSON_GetObjectItemCaseSensitive(result_obj, "public_key");
+            check_condition("secp256k1 structured has public_key (64 hex chars)",
+                            pk_item != NULL && cJSON_IsString(pk_item) &&
+                            strlen(pk_item->valuestring) == 64);
+        } else {
+            check_condition("secp256k1 structured has public_key (64 hex chars)", 0);
+        }
+        check_condition("secp256k1 structured has algorithm field",
+                        response_has(resp, "algorithm"));
 
         free(result_str);
         cJSON_Delete(result_obj);
@@ -584,7 +587,7 @@ int main(void) {
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &g_key_store, &g_alg_key_cache);
 
         resp = dispatcher_handle_request(&dispatcher,
-                                          "{\"id\":\"2\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"main\",\"format\":\"structured\"}]}");
+                                          "{\"id\":\"2\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"secp256k1\",\"index\":0,\"format\":\"structured\"}]}");
         check_condition("secp256k1 structured get_public_key returns a response", resp != NULL);
 
         pr = parse_result(resp, &result_str, &result_obj);
@@ -645,7 +648,7 @@ int main(void) {
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &g_key_store, &g_alg_key_cache);
 
         resp = dispatcher_handle_request(&dispatcher,
-                                          "{\"id\":\"3\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"ssh_main\"}]}");
+                                          "{\"id\":\"3\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"ed25519\",\"index\":0}]}");
         check_condition("ed25519 get_public_key returns a response", resp != NULL);
 
         pr = parse_result(resp, &result_str, &result_obj);
@@ -710,7 +713,7 @@ int main(void) {
         check_condition("ML-DSA-65 sizes available", sz != NULL);
 
         resp = dispatcher_handle_request(&dispatcher,
-                                          "{\"id\":\"4\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"pq_sig\"}]}");
+                                          "{\"id\":\"4\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"ml-dsa-65\",\"index\":0}]}");
         check_condition("ML-DSA-65 get_public_key returns a response", resp != NULL);
 
         pr = parse_result(resp, &result_str, &result_obj);
@@ -775,7 +778,7 @@ int main(void) {
         check_condition("ML-KEM-768 sizes available", sz != NULL);
 
         resp = dispatcher_handle_request(&dispatcher,
-                                          "{\"id\":\"5\",\"method\":\"get_public_key\",\"params\":[{\"role\":\"kem_main\"}]}");
+                                          "{\"id\":\"5\",\"method\":\"get_public_key\",\"params\":[{\"algorithm\":\"ml-kem-768\",\"index\":0}]}");
         check_condition("ML-KEM-768 get_public_key returns a response", resp != NULL);
 
         pr = parse_result(resp, &result_str, &result_obj);

tests/test_qrexec_auth.c

@@ -304,7 +304,7 @@ int main(void) {
     check_condition("nostr_init for auth signing", nostr_init() == 0);
 
     /* no auth => legacy qubes:personal preapprove should match */
-    if (run_qrexec_once("{\"id\":\"1\",\"method\":\"get_public_key\",\"params\":[\"\"]}", &resp) == 0) {
+    if (run_qrexec_once("{\"id\":\"1\",\"method\":\"nostr_get_public_key\",\"params\":[\"\"]}", &resp) == 0) {
         check_condition("qrexec optional/no-auth still allows legacy qubes caller preapprove",
                         strstr(resp, "\"result\":") != NULL);
         free(resp);
@@ -313,7 +313,7 @@ int main(void) {
         check_condition("qrexec optional/no-auth request roundtrip", 0);
     }
 
-    auth_req = build_auth_request(privkey, "2", "get_public_key");
+    auth_req = build_auth_request(privkey, "2", "nostr_get_public_key");
     check_condition("build qrexec auth request", auth_req != NULL);
     if (auth_req != NULL) {
         if (run_qrexec_once(auth_req, &resp) == 0) {
@@ -328,7 +328,7 @@ int main(void) {
         auth_req = NULL;
     }
 
-    auth_req = build_auth_request(privkey, "3", "get_public_key");
+    auth_req = build_auth_request(privkey, "3", "nostr_get_public_key");
     check_condition("build second qrexec auth request", auth_req != NULL);
     if (auth_req != NULL) {
         cJSON *root = cJSON_Parse(auth_req);
@@ -338,7 +338,7 @@ int main(void) {
         if (root != NULL) {
             method_item = cJSON_GetObjectItemCaseSensitive(root, "method");
             if (cJSON_IsString(method_item)) {
-                cJSON_SetValuestring(method_item, "sign_event");
+                cJSON_SetValuestring(method_item, "nostr_sign_event");
             }
             tampered = cJSON_PrintUnformatted(root);
             cJSON_Delete(root);

tests/test_role_table.c

@@ -211,6 +211,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -220,22 +221,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */

tests/test_selector.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */

tests/test_slh_dsa_128s.c

@@ -8,8 +8,8 @@
  *   - SLH-DSA-128s sign/verify with wrong key: verify fails
  *   - DRBG determinism: same seed -> same randombytes output
  *   - Integration: derive SLH-DSA-128s key from mnemonic via crypto_derive_one,
- *     sign data via sign_data verb through dispatcher, verify signature
- *   - Enforcement: sign_data allowed on pq-sig+slh-dsa-128s
+ *     sign data via sign verb through dispatcher, verify signature
+ *   - Enforcement: sign allowed on pq-sig+slh-dsa-128s
  */
 /* NSIGNER_HEADERLESS_DECLS_BEGIN */
 #include <stddef.h>
@@ -142,19 +142,22 @@ const char *selector_strerror(int err);
 #define ENFORCE_ERR_PURPOSE      -1
 #define ENFORCE_ERR_CURVE        -2
 #define ENFORCE_ERR_UNKNOWN_VERB -3
+#define ENFORCE_ERR_ALGORITHM   -4
 
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
-#define VERB_MINE_EVENT     "mine_event"
-#define VERB_SIGN_DATA      "sign_data"
-#define VERB_VERIFY_SIG     "verify_signature"
-#define VERB_SSH_SIGN       "ssh_sign"
-#define VERB_KEM_ENCAPS     "kem_encapsulate"
-#define VERB_KEM_DECAPS     "kem_decapsulate"
+#define VERB_SIGN                 "sign"
+#define VERB_VERIFY               "verify"
+#define VERB_ENCAPSULATE          "encapsulate"
+#define VERB_DECAPSULATE          "decapsulate"
+#define VERB_DERIVE_SHARED        "derive_shared_secret"
+#define VERB_DERIVE           "derive"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_MINE_EVENT     "nostr_mine_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 int enforce_verb_role(const char *verb, const role_entry_t *role);
 const char *enforce_strerror(int err);
@@ -682,7 +685,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: sign_data via dispatcher ---- */
+    /* ---- Integration: sign via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t pq_role;
@@ -705,16 +708,16 @@ int main(void) {
 
         dispatcher_init(&dispatcher, &table, &mnemonic_state, &g_key_store, &g_alg_key_cache);
 
-        /* sign_data request */
+        /* sign request */
         snprintf(request, sizeof(request),
-                 "{\"id\":\"test1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"pq_main\"}]}",
+                 "{\"id\":\"test1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"slh-dsa-128s\",\"index\":0}]}",
                  msg_hex);
         resp = dispatcher_handle_request(&dispatcher, request);
-        check_condition("sign_data via dispatcher returns result",
+        check_condition("sign via dispatcher returns result",
                         resp != NULL && response_has(resp, "\"result\""));
-        check_condition("sign_data result contains signature",
+        check_condition("sign result contains signature",
                         resp != NULL && response_has(resp, "signature"));
-        check_condition("sign_data result contains algorithm slh-dsa-128s",
+        check_condition("sign result contains algorithm slh-dsa-128s",
                         resp != NULL && response_has(resp, "slh-dsa-128s"));
         free(resp);
 
@@ -722,7 +725,7 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Integration: verify_signature roundtrip via dispatcher ---- */
+    /* ---- Integration: verify roundtrip via dispatcher ---- */
     {
         role_table_t table;
         role_entry_t pq_role;
@@ -752,10 +755,10 @@ int main(void) {
 
         /* Sign */
         snprintf(sign_req, sizeof(sign_req),
-                 "{\"id\":\"s1\",\"method\":\"sign_data\",\"params\":[\"%s\",{\"role\":\"pq_main\"}]}",
+                 "{\"id\":\"s1\",\"method\":\"sign\",\"params\":[\"%s\",{\"algorithm\":\"slh-dsa-128s\",\"index\":0}]}",
                  msg_hex);
         sign_resp = dispatcher_handle_request(&dispatcher, sign_req);
-        check_condition("verify roundtrip: sign_data succeeds", sign_resp != NULL);
+        check_condition("verify roundtrip: sign succeeds", sign_resp != NULL);
 
         /* Extract signature from result */
         if (sign_resp != NULL) {
@@ -780,28 +783,28 @@ int main(void) {
         /* Verify */
         if (sig_str != NULL && verify_req != NULL) {
             snprintf(verify_req, 20000,
-                     "{\"id\":\"v1\",\"method\":\"verify_signature\",\"params\":[\"%s\",\"%s\",{\"role\":\"pq_main\"}]}",
+                     "{\"id\":\"v1\",\"method\":\"verify\",\"params\":[\"%s\",\"%s\",{\"algorithm\":\"slh-dsa-128s\",\"index\":0}]}",
                      msg_hex, sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature returns valid:true",
+            check_condition("verify returns valid:true",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "true"));
             free(verify_resp);
 
             /* Verify with wrong message */
             snprintf(verify_req, 20000,
-                     "{\"id\":\"v2\",\"method\":\"verify_signature\",\"params\":[\"00ff\",\"%s\",{\"role\":\"pq_main\"}]}",
+                     "{\"id\":\"v2\",\"method\":\"verify\",\"params\":[\"00ff\",\"%s\",{\"algorithm\":\"slh-dsa-128s\",\"index\":0}]}",
                      sig_str);
             verify_resp = dispatcher_handle_request(&dispatcher, verify_req);
-            check_condition("verify_signature wrong msg returns valid:false",
+            check_condition("verify wrong msg returns valid:false",
                             verify_resp != NULL && response_has(verify_resp, "valid") &&
                             response_has(verify_resp, "false"));
             free(verify_resp);
 
             free((void *)sig_str);
         } else {
-            check_condition("verify_signature returns valid:true", 0);
-            check_condition("verify_signature wrong msg returns valid:false", 0);
+            check_condition("verify returns valid:true", 0);
+            check_condition("verify wrong msg returns valid:false", 0);
         }
 
         free(verify_req);
@@ -810,19 +813,23 @@ int main(void) {
         mnemonic_unload(&mnemonic_state);
     }
 
-    /* ---- Enforcement: sign_data on pq-sig+slh-dsa-128s ---- */
+    /* ---- Enforcement: sign on pq-sig+slh-dsa-128s ---- */
     {
         role_entry_t pq_sig = make_pq_sig_slh_dsa_128s_entry("pq", 0);
         role_entry_t nostr_secp = make_nostr_secp_entry("nostr", 0);
 
-        check_condition("enforce sign_data + pq-sig/slh-dsa-128s -> OK",
-                        enforce_verb_role(VERB_SIGN_DATA, &pq_sig) == ENFORCE_OK);
+        /* sign/verify are algorithm-based now. */
+        check_condition("enforce sign + slh-dsa-128s -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_SLH_DSA_128S) == ENFORCE_OK);
 
-        check_condition("enforce sign_data + nostr/secp256k1 -> PURPOSE err",
-                        enforce_verb_role(VERB_SIGN_DATA, &nostr_secp) == ENFORCE_ERR_PURPOSE);
+        check_condition("enforce sign + secp256k1 -> OK",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_SECP256K1) == ENFORCE_OK);
 
-        check_condition("enforce verify_signature + pq-sig/slh-dsa-128s -> OK",
-                        enforce_verb_role(VERB_VERIFY_SIG, &pq_sig) == ENFORCE_OK);
+        check_condition("enforce verify + slh-dsa-128s -> OK",
+                        enforce_verb_algorithm(VERB_VERIFY, CRYPTO_ALG_SLH_DSA_128S) == ENFORCE_OK);
+
+        check_condition("enforce sign + ml-kem-768 -> ALGORITHM err",
+                        enforce_verb_algorithm(VERB_SIGN, CRYPTO_ALG_ML_KEM_768) == ENFORCE_ERR_ALGORITHM);
     }
 
     /* ---- Cleanup ---- */

tests/test_socket_name.c

@@ -208,6 +208,7 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 #define ENFORCE_ERR_ALGORITHM  -4 /* algorithm not valid for verb */
 
@@ -217,22 +218,24 @@ const char *selector_strerror(int err);
 #define VERB_ENCAPSULATE       "encapsulate"
 #define VERB_DECAPSULATE       "decapsulate"
 #define VERB_DERIVE_SHARED     "derive_shared_secret"
+#define VERB_DERIVE          "derive"
 
 
 /* Known verbs */
-#define VERB_SIGN_EVENT     "sign_event"
 #define VERB_GET_PUBLIC_KEY       "get_public_key"
-#define VERB_NIP44_ENCRYPT  "nip44_encrypt"
-#define VERB_NIP44_DECRYPT  "nip44_decrypt"
-#define VERB_NIP04_ENCRYPT  "nip04_encrypt"
-#define VERB_NIP04_DECRYPT  "nip04_decrypt"
+#define VERB_NOSTR_GET_PUBLIC_KEY "nostr_get_public_key"
+#define VERB_NOSTR_SIGN_EVENT     "nostr_sign_event"
+#define VERB_NOSTR_NIP44_ENCRYPT  "nostr_nip44_encrypt"
+#define VERB_NOSTR_NIP44_DECRYPT  "nostr_nip44_decrypt"
+#define VERB_NOSTR_NIP04_ENCRYPT  "nostr_nip04_encrypt"
+#define VERB_NOSTR_NIP04_DECRYPT  "nostr_nip04_decrypt"
 
 /*
  * Check whether `verb` is allowed to execute against `role`.
  * Returns ENFORCE_OK if allowed, or an ENFORCE_ERR_* code.
  *
  * The enforcement rules are:
- *   - All nostr verbs (sign_event, get_public_key, nip44_*, nip04_*) require:
+ *   - All nostr verbs (nostr_sign_event, nostr_get_public_key, nostr_nip44_*, nostr_nip04_*) require:
  *     purpose == PURPOSE_NOSTR and curve == CURVE_SECP256K1
  *   - Unknown verbs return ENFORCE_ERR_UNKNOWN_VERB (fail-closed).
  */

tools/http_test.py

@@ -0,0 +1,141 @@
+#!/usr/bin/env python3
+"""
+http_test.py — test the HTTP listener mode with curl-like requests.
+
+Starts nsigner in HTTP mode, sends requests via urllib, and verifies
+the responses.
+"""
+import json
+import os
+import subprocess
+import sys
+import time
+import urllib.request
+
+NSIGNER = "./build/nsigner"
+PAD_DIR = "/media/user/Music/pads"
+PAD_SPEC = "333e9902db839d9d"
+MNEMONIC_FILE = ".test_mnemonic"
+MNEMONIC_TMP = ".test_mnemonic_http.tmp"
+PORT = 11111
+
+
+def main():
+    # Reset pad offset
+    state_path = f"{PAD_DIR}/333e9902db839d9d7f1f6aaa30f392a77c9abd011dd6274d9d3cf167361a789e.state"
+    with open(state_path, "w") as f:
+        f.write("offset=32\n")
+
+    # Prepare mnemonic temp file
+    with open(MNEMONIC_FILE) as f:
+        mnemonic = f.read().strip()
+    with open(MNEMONIC_TMP, "w") as f:
+        f.write(mnemonic + "\n")
+
+    # Start nsigner in HTTP mode
+    shell_cmd = (
+        f"exec 3<{MNEMONIC_TMP} 2>/dev/null; "
+        f"exec {NSIGNER} --listen http:127.0.0.1:{PORT} --mnemonic-fd 3 "
+        f"--otp-pad-dir {PAD_DIR} --otp-pad {PAD_SPEC} "
+        f"--otp-allow-blkback --allow-all"
+    )
+    proc = subprocess.Popen(
+        ["bash", "-c", shell_cmd],
+        stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+    )
+    time.sleep(2.0)  # let the signer start
+
+    if proc.poll() is not None:
+        err = proc.stderr.read().decode()
+        print(f"ERROR: nsigner exited early (code {proc.returncode})")
+        print(f"stderr: {err}")
+        try:
+            os.unlink(MNEMONIC_TMP)
+        except OSError:
+            pass
+        return 1
+
+    try:
+        url = f"http://127.0.0.1:{PORT}/"
+
+        # Test 1: get_public_key
+        print("=== Test 1: get_public_key via HTTP ===")
+        req_data = json.dumps({
+            "id": "1",
+            "method": "get_public_key",
+            "params": [{"role": "main"}],
+        }).encode()
+        req = urllib.request.Request(url, data=req_data,
+                                      headers={"Content-Type": "application/json"})
+        with urllib.request.urlopen(req, timeout=5) as resp:
+            result = json.loads(resp.read().decode())
+        print(f"Response: {json.dumps(result)[:120]}...")
+        if "result" not in result:
+            print("ERROR: no result in get_public_key response")
+            return 1
+        pubkey = result["result"].strip('"')
+        print(f"Public key: {pubkey}")
+
+        # Test 2: otp_encrypt
+        print("\n=== Test 2: otp_encrypt via HTTP ===")
+        import base64
+        pt_b64 = base64.b64encode(b"Hello, OTP via HTTP!").decode()
+        req_data = json.dumps({
+            "id": "2",
+            "method": "otp_encrypt",
+            "params": [pt_b64, {"encoding": "ascii"}],
+        }).encode()
+        req = urllib.request.Request(url, data=req_data,
+                                      headers={"Content-Type": "application/json"})
+        with urllib.request.urlopen(req, timeout=5) as resp:
+            result = json.loads(resp.read().decode())
+        print(f"Response: {json.dumps(result)[:200]}...")
+        if "result" not in result:
+            print("ERROR: no result in otp_encrypt response")
+            return 1
+        enc_result = json.loads(result["result"])
+        ciphertext = enc_result["ciphertext"]
+        print(f"Pad offset: {enc_result['pad_offset_before']} -> {enc_result['pad_offset_after']}")
+        print(f"Ciphertext (first 60 chars): {ciphertext[:60]}...")
+
+        # Test 3: otp_decrypt
+        print("\n=== Test 3: otp_decrypt via HTTP ===")
+        req_data = json.dumps({
+            "id": "3",
+            "method": "otp_decrypt",
+            "params": [ciphertext, {"encoding": "ascii"}],
+        }).encode()
+        req = urllib.request.Request(url, data=req_data,
+                                      headers={"Content-Type": "application/json"})
+        with urllib.request.urlopen(req, timeout=5) as resp:
+            result = json.loads(resp.read().decode())
+        print(f"Response: {json.dumps(result)[:200]}...")
+        if "result" not in result:
+            print("ERROR: no result in otp_decrypt response")
+            return 1
+        dec_result = json.loads(result["result"])
+        recovered = base64.b64decode(dec_result["plaintext"]).decode()
+        print(f"Recovered plaintext: {recovered}")
+
+        if recovered == "Hello, OTP via HTTP!":
+            print("\n=== HTTP ROUND-TRIP SUCCESS ===")
+            return 0
+        else:
+            print("\n=== HTTP ROUND-TRIP FAILED ===")
+            print(f"Expected: Hello, OTP via HTTP!")
+            print(f"Got:      {recovered}")
+            return 1
+    finally:
+        proc.terminate()
+        try:
+            proc.wait(timeout=3)
+        except subprocess.TimeoutExpired:
+            proc.kill()
+        try:
+            os.unlink(MNEMONIC_TMP)
+        except OSError:
+            pass
+
+
+if __name__ == "__main__":
+    sys.exit(main())

tools/make_test_pad.c

@@ -0,0 +1,228 @@
+/*
+ * make_test_pad.c — generate a small test OTP pad on a target directory.
+ *
+ * Bit-compatible with the `otp` project's pad format:
+ *   - <chksum>.pad : raw random bytes, first 32 bytes are the "reserved header"
+ *     (also used as the key to encrypt the checksum).
+ *   - <chksum>.state : text file "offset=32\n" (32-byte header reserved).
+ *   - chksum is the 64-hex-char XOR checksum as computed by
+ *     otp/src/crypto.c:calculate_checksum (position-dependent XOR folded into
+ *     32 buckets, then XORed with the first 32 pad bytes).
+ *
+ * Usage:
+ *   make_test_pad <pad_dir> <size_bytes>
+ *
+ * Example:
+ *   make_test_pad /media/user/USBDISK/pads 1048576
+ *
+ * Entropy source: /dev/urandom (local-entropy test path only — NOT for production
+ * pads; production pads should use the `otp` CLI with keyboard/TRNG entropy or a
+ * future hardware signer).
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#define CHKSUM_HEX_LEN 64
+#define CHKSUM_BIN_LEN 32
+#define HEADER_RESERVED 32
+#define BUF_SIZE (64 * 1024)
+
+static int compute_checksum(const char *pad_path, char *checksum_hex) {
+    FILE *file = fopen(pad_path, "rb");
+    if (!file) {
+        fprintf(stderr, "compute_checksum: cannot open %s: %s\n",
+                pad_path, strerror(errno));
+        return 1;
+    }
+
+    unsigned char checksum[CHKSUM_BIN_LEN];
+    unsigned char buffer[BUF_SIZE];
+    size_t bytes_read;
+    size_t total_bytes = 0;
+
+    memset(checksum, 0, CHKSUM_BIN_LEN);
+
+    while ((bytes_read = fread(buffer, 1, sizeof(buffer), file)) > 0) {
+        for (size_t i = 0; i < bytes_read; i++) {
+            size_t pos = total_bytes + i;
+            unsigned char bucket = (unsigned char)(pos % CHKSUM_BIN_LEN);
+            checksum[bucket] ^= buffer[i] ^
+                               (unsigned char)((pos >> 8) & 0xFF) ^
+                               (unsigned char)((pos >> 16) & 0xFF) ^
+                               (unsigned char)((pos >> 24) & 0xFF);
+        }
+        total_bytes += bytes_read;
+    }
+    fclose(file);
+
+    /* XOR the checksum with the first 32 bytes of the pad (the "pad key"). */
+    file = fopen(pad_path, "rb");
+    if (!file) {
+        fprintf(stderr, "compute_checksum: cannot reopen %s: %s\n",
+                pad_path, strerror(errno));
+        return 1;
+    }
+    unsigned char pad_key[CHKSUM_BIN_LEN];
+    if (fread(pad_key, 1, CHKSUM_BIN_LEN, file) != CHKSUM_BIN_LEN) {
+        fprintf(stderr, "compute_checksum: pad too small for header key\n");
+        fclose(file);
+        return 1;
+    }
+    fclose(file);
+
+    unsigned char encrypted_checksum[CHKSUM_BIN_LEN];
+    for (int i = 0; i < CHKSUM_BIN_LEN; i++) {
+        encrypted_checksum[i] = checksum[i] ^ pad_key[i];
+    }
+
+    for (int i = 0; i < CHKSUM_BIN_LEN; i++) {
+        sprintf(checksum_hex + (i * 2), "%02x", encrypted_checksum[i]);
+    }
+    checksum_hex[CHKSUM_HEX_LEN] = '\0';
+    return 0;
+}
+
+static int write_random(const char *path, size_t size) {
+    int urand = open("/dev/urandom", O_RDONLY);
+    if (urand < 0) {
+        fprintf(stderr, "cannot open /dev/urandom: %s\n", strerror(errno));
+        return 1;
+    }
+
+    int out = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+    if (out < 0) {
+        fprintf(stderr, "cannot create %s: %s\n", path, strerror(errno));
+        close(urand);
+        return 1;
+    }
+
+    unsigned char buffer[BUF_SIZE];
+    size_t written = 0;
+    while (written < size) {
+        size_t chunk = size - written;
+        if (chunk > sizeof(buffer)) chunk = sizeof(buffer);
+
+        ssize_t got = 0;
+        while ((size_t)got < chunk) {
+            ssize_t r = read(urand, buffer + got, chunk - (size_t)got);
+            if (r < 0) {
+                if (errno == EINTR) continue;
+                fprintf(stderr, "read urandom failed: %s\n", strerror(errno));
+                close(out);
+                close(urand);
+                return 1;
+            }
+            if (r == 0) {
+                fprintf(stderr, "urandom EOF (unexpected)\n");
+                close(out);
+                close(urand);
+                return 1;
+            }
+            got += r;
+        }
+
+        ssize_t put = 0;
+        while (put < got) {
+            ssize_t w = write(out, buffer + put, (size_t)got - (size_t)put);
+            if (w < 0) {
+                if (errno == EINTR) continue;
+                fprintf(stderr, "write %s failed: %s\n", path, strerror(errno));
+                close(out);
+                close(urand);
+                return 1;
+            }
+            put += w;
+        }
+        written += (size_t)got;
+    }
+
+    close(out);
+    close(urand);
+    return 0;
+}
+
+int main(int argc, char *argv[]) {
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <pad_dir> <size_bytes>\n", argv[0]);
+        return 1;
+    }
+
+    const char *pad_dir = argv[1];
+    size_t size = (size_t)strtoull(argv[2], NULL, 10);
+    if (size < 64) {
+        fprintf(stderr, "size must be at least 64 bytes\n");
+        return 1;
+    }
+
+    /* Ensure pad_dir exists. */
+    struct stat st;
+    if (stat(pad_dir, &st) != 0) {
+        if (mkdir(pad_dir, 0755) != 0) {
+            fprintf(stderr, "cannot create %s: %s\n", pad_dir, strerror(errno));
+            return 1;
+        }
+    } else if (!S_ISDIR(st.st_mode)) {
+        fprintf(stderr, "%s exists but is not a directory\n", pad_dir);
+        return 1;
+    }
+
+    /* Write the pad to a temporary name first, then rename by checksum. */
+    char tmp_path[1024];
+    snprintf(tmp_path, sizeof(tmp_path), "%s/.tmp_pad_XXXXXX", pad_dir);
+    /* mkstemp would be cleaner, but we want a stable name for the rename. */
+    int tfd = mkstemp(tmp_path);
+    if (tfd < 0) {
+        fprintf(stderr, "mkstemp failed: %s\n", strerror(errno));
+        return 1;
+    }
+    close(tfd);
+
+    if (write_random(tmp_path, size) != 0) {
+        unlink(tmp_path);
+        return 1;
+    }
+
+    char chksum[CHKSUM_HEX_LEN + 1];
+    if (compute_checksum(tmp_path, chksum) != 0) {
+        unlink(tmp_path);
+        return 1;
+    }
+
+    char final_path[1024];
+    char state_path[1024];
+    snprintf(final_path, sizeof(final_path), "%s/%s.pad", pad_dir, chksum);
+    snprintf(state_path, sizeof(state_path), "%s/%s.state", pad_dir, chksum);
+
+    if (rename(tmp_path, final_path) != 0) {
+        fprintf(stderr, "rename %s -> %s failed: %s\n",
+                tmp_path, final_path, strerror(errno));
+        unlink(tmp_path);
+        return 1;
+    }
+
+    /* Write initial state file: offset=32 (header reserved). */
+    FILE *state = fopen(state_path, "w");
+    if (!state) {
+        fprintf(stderr, "cannot create %s: %s\n", state_path, strerror(errno));
+        return 1;
+    }
+    fprintf(state, "offset=%d\n", HEADER_RESERVED);
+    fclose(state);
+
+    printf("Created test pad:\n");
+    printf("  pad:   %s\n", final_path);
+    printf("  state: %s\n", state_path);
+    printf("  size:  %zu bytes\n", size);
+    printf("  chksum: %s\n", chksum);
+    printf("  chksum prefix (16 chars): %.16s\n", chksum);
+    return 0;
+}

tools/otp_roundtrip_test.py

@@ -0,0 +1,213 @@
+#!/usr/bin/env python3
+"""
+otp_roundtrip_test.py — end-to-end test of otp_encrypt / otp_decrypt verbs.
+
+Sends framed JSON-RPC requests to nsigner --listen stdio and checks the
+round-trip: plaintext -> otp_encrypt -> otp_decrypt -> recovered plaintext.
+
+Framing: 4-byte big-endian length prefix + JSON payload.
+
+Usage: python3 tools/otp_roundtrip_test.py
+"""
+import base64
+import json
+import os
+import struct
+import subprocess
+import sys
+import tempfile
+import time
+
+NSIGNER = "./build/nsigner"
+PAD_DIR = "/media/user/Music/pads"
+PAD_SPEC = "333e9902db839d9d"
+MNEMONIC_FILE = ".test_mnemonic"
+
+
+def send_framed(proc, obj):
+    payload = json.dumps(obj).encode()
+    proc.stdin.write(struct.pack(">I", len(payload)))
+    proc.stdin.write(payload)
+    proc.stdin.flush()
+
+
+def recv_framed(proc):
+    """Read a framed response, skipping any banner text the signer writes
+    to stdout before the first frame. The banner is line-based ASCII; a
+    valid frame starts with a 4-byte big-endian length followed by '{'."""
+    # Read 4 bytes at a time, sliding window, until we find a frame header.
+    buf = b""
+    while True:
+        b = proc.stdout.read(1)
+        if not b:
+            return None
+        buf = (buf + b)[-4:]
+        if len(buf) < 4:
+            continue
+        (length,) = struct.unpack(">I", buf)
+        # Sanity: frame length should be reasonable (1..1MB) and the next
+        # byte after the header should be '{' (start of JSON).
+        if 1 <= length <= 1024 * 1024:
+            # Peek: read one more byte to check for '{'.
+            peek = proc.stdout.read(1)
+            if peek == b'{':
+                body = peek + proc.stdout.read(length - 1)
+                return json.loads(body.decode())
+            else:
+                # Not a frame; prepend peek to the stream by including it
+                # in the sliding window.
+                buf = (buf + peek)[-4:]
+        # Otherwise keep scanning.
+
+
+def main():
+    if not os.path.isfile(NSIGNER):
+        print(f"ERROR: {NSIGNER} not found. Run 'make dev' first.")
+        return 1
+
+    with open(MNEMONIC_FILE) as f:
+        mnemonic = f.read().strip()
+
+    plaintext = b"Hello, OTP world!"
+    pt_b64 = base64.b64encode(plaintext).decode()
+    print(f"Plaintext: {plaintext.decode()}")
+    print(f"Plaintext base64: {pt_b64}")
+
+    # Write the mnemonic to a fixed temp file and pass it as fd 3 to nsigner
+    # via a bash wrapper (so stdin stays free for framed requests).
+    mnem_path = ".test_mnemonic_otp_roundtrip.tmp"
+    with open(mnem_path, "w") as f:
+        f.write(mnemonic + "\n")
+
+    def run_one_request(req_obj):
+        """Run nsigner in stdio mode for a single framed request/response.
+        Returns the parsed JSON response or None."""
+        shell_cmd = (
+            f"exec 3<{mnem_path}; "
+            f"exec {NSIGNER} --listen stdio --mnemonic-fd 3 "
+            f"--otp-pad-dir {PAD_DIR} --otp-pad {PAD_SPEC} "
+            f"--otp-allow-blkback --allow-all"
+        )
+        proc = subprocess.Popen(
+            ["bash", "-c", shell_cmd],
+            stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+            text=False,
+        )
+        time.sleep(1.5)  # let the signer bind the pad and be ready
+        if proc.poll() is not None:
+            err = proc.stderr.read().decode()
+            print(f"ERROR: nsigner exited early (code {proc.returncode})")
+            print(f"stderr: {err}")
+            return None
+        send_framed(proc, req_obj)
+        resp = recv_framed(proc)
+        proc.stdin.close()
+        try:
+            proc.wait(timeout=5)
+        except subprocess.TimeoutExpired:
+            proc.kill()
+        return resp
+
+    # --- otp_encrypt ---
+    print("\n=== Sending otp_encrypt ===")
+    resp = run_one_request({
+        "id": "1",
+        "method": "otp_encrypt",
+        "params": [pt_b64, {"encoding": "ascii"}],
+    })
+    print(f"Encrypt response: {json.dumps(resp)}")
+
+    if resp is None or "result" not in resp:
+        print("ERROR: no result in encrypt response")
+        try:
+            os.unlink(mnem_path)
+        except OSError:
+            pass
+        return 1
+
+    result_obj = json.loads(resp["result"])
+    ciphertext = result_obj["ciphertext"]
+    off_before = result_obj["pad_offset_before"]
+    off_after = result_obj["pad_offset_after"]
+    print(f"Pad offset: {off_before} -> {off_after} "
+          f"(consumed {off_after - off_before} bytes)")
+    print(f"Ciphertext (first 80 chars): {ciphertext[:80]}...")
+
+    # --- otp_decrypt (separate invocation; offset persists in .state) ---
+    print("\n=== Sending otp_decrypt ===")
+    resp2 = run_one_request({
+        "id": "2",
+        "method": "otp_decrypt",
+        "params": [ciphertext, {"encoding": "ascii"}],
+    })
+    print(f"Decrypt response: {json.dumps(resp2)}")
+
+    if resp2 is None or "result" not in resp2:
+        print("ERROR: no result in decrypt response")
+        return 1
+
+    result2 = json.loads(resp2["result"])
+    recovered_b64 = result2["plaintext"]
+    recovered = base64.b64decode(recovered_b64)
+    print(f"\nRecovered plaintext: {recovered.decode()}")
+
+    if recovered == plaintext:
+        print("\n=== ASCII ROUND-TRIP SUCCESS ===")
+    else:
+        print("\n=== ASCII ROUND-TRIP FAILED ===")
+        print(f"Expected: {plaintext.decode()}")
+        print(f"Got:      {recovered.decode()}")
+        return 1
+
+    # --- Binary encoding round-trip ---
+    # Reset the pad offset for a clean binary test.
+    state_path = (f"{PAD_DIR}/{result_obj['pad_chksum']}.state")
+    with open(state_path, "w") as sf:
+        sf.write("offset=32\n")
+
+    print("\n=== Sending otp_encrypt (binary) ===")
+    resp3 = run_one_request({
+        "id": "3",
+        "method": "otp_encrypt",
+        "params": [pt_b64, {"encoding": "binary"}],
+    })
+    print(f"Binary encrypt response: {json.dumps(resp3)}")
+    if resp3 is None or "result" not in resp3:
+        print("ERROR: no result in binary encrypt response")
+        return 1
+    result3 = json.loads(resp3["result"])
+    bin_b64 = result3["ciphertext"]
+    # The binary ciphertext is base64-encoded in the JSON result.
+    bin_blob = base64.b64decode(bin_b64)
+    print(f"Binary blob size: {len(bin_blob)} bytes "
+          f"(header 58 + padded data {len(bin_blob) - 58})")
+    if not bin_blob[:4] == b"OTP\0":
+        print("ERROR: binary blob missing OTP magic")
+        return 1
+
+    print("\n=== Sending otp_decrypt (binary) ===")
+    resp4 = run_one_request({
+        "id": "4",
+        "method": "otp_decrypt",
+        "params": [bin_b64, {"encoding": "binary"}],
+    })
+    print(f"Binary decrypt response: {json.dumps(resp4)}")
+    if resp4 is None or "result" not in resp4:
+        print("ERROR: no result in binary decrypt response")
+        return 1
+    result4 = json.loads(resp4["result"])
+    recovered2 = base64.b64decode(result4["plaintext"])
+    print(f"\nRecovered plaintext (binary path): {recovered2.decode()}")
+
+    if recovered2 == plaintext:
+        print("\n=== BINARY ROUND-TRIP SUCCESS ===")
+        return 0
+    else:
+        print("\n=== BINARY ROUND-TRIP FAILED ===")
+        print(f"Expected: {plaintext.decode()}")
+        print(f"Got:      {recovered2.decode()}")
+        return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())