Johnathan Corgan feb1e02e9c Verify the peer static on both FMP handshake paths, not just at rekey
Under Noise XX the peer static key is learned during the handshake rather
than pinned in advance, and neither of the two paths that learn one was
checking it against what we already knew. That let an attacker who could
observe and inject on path substitute their own identity, on both a fresh
dial and an established link.

On a fresh dial we recorded who we meant to reach and then overwrote it
with whoever answered, without ever comparing the two. Promotion, the ACL
check and the peer registry all then ran on the answering identity, so an
attacker who raced the real peer to msg2 became the peer and the intended
node was never reached. On an established link, a rekey msg2 was matched
to its peer only by the session index we had put in the cleartext msg1
header, so anyone who saw that header could answer with their own static
and take the link over at the cutover.

Both are now compared before anything is committed. The dial-time
expectation moves into its own field with no setter, so the handshake
cannot overwrite it the way it used to; the identity learned from msg2
keeps landing where it always did. Anonymous dials still promote whoever
answers, which is what shared-media discovery means, and that branch is
chosen locally when we dial rather than from anything on the wire, so it
cannot be reached as an exemption. Both comparisons are decisions made in
the synchronous core alongside the existing classifiers.

The gates sit ahead of every mutation, not merely ahead of the session
install, so a forged msg2 no longer poisons the recorded peer epoch and
never earns a msg3. A rejected dial is rescheduled from the dial-time
expectation rather than the answering identity, so refusing an impostor
does not silently retire a configured peer from the dial schedule.

Only this branch was exposed. The released lines use Noise IK, where the
initiator pins the responder static before it dials and a wrong key fails
the AEAD outright.

No wire change: both gates compare a value we already learn against one
we already hold, and legitimate handshakes behave exactly as before.

Six tests cover it, driving the real cadence and dial paths with a third
node answering the intercepted message. Each was checked to fail when the
decision is forced to accept. Local CI 37/37.
2026-07-21 19:40:50 +00:00
2026-07-16 05:56:36 +00:00
2026-07-19 07:40:07 +00:00
2026-02-22 20:52:55 +00:00

FIPS: Free Internetworking Peering System

banner License: MIT Rust Status

A self-organizing encrypted mesh network built on Nostr identities, capable of operating over arbitrary transports without central infrastructure.

FIPS is under active development. The protocol and APIs are not yet stable. See Status & roadmap below.

What FIPS does

A machine running FIPS becomes a node in the mesh with a self-generated cryptographic identity (a Nostr keypair). There are two equally-supported deployment modes.

As an overlay on top of existing IP networks, FIPS lets your node reach any other FIPS node wherever it sits — behind a NAT, on a different ISP, on a phone over cellular, on a laptop with only Bluetooth in range, or behind a Tor onion. The mesh forwards IPv6 traffic transparently and end-to-end encrypted, with no central VPN concentrator or coordinating server.

Ground up over raw Ethernet, WiFi, or Bluetooth, FIPS provides a complete permissionless network without any pre-existing IP infrastructure, ISP, or DNS. Any node that joins the link gets routable IPv6 addresses, peer discovery, and a path to every other node automatically.

Either way, existing networking software runs over it unchanged — SSH, HTTP servers, file transfer, anything IPv6-native works the same way it would on a local network.

Features

  • Self-organizing mesh routing. Spanning-tree coordinates with bloom-filter-guided discovery; no global routing tables, no flooding.
  • Multi-transport. UDP, TCP, Ethernet, Tor, Nym, and Bluetooth (BLE L2CAP) ship today; transports compose on a single mesh and a node may run several at once.
  • Two-layer encryption. Noise XX both hop-by-hop (peer links) and end-to-end (mesh sessions), with periodic rekey for forward secrecy and protocol negotiation in the handshake.
  • Nostr-native identity. secp256k1 / schnorr keypairs as node addresses; self-generated, no registration, no central authority.
  • IPv6 adapter. A TUN interface maps each remote npub to an fd00::/8 address, so unmodified IPv6 software reaches mesh peers as <npub>.fips. Built-in .fips DNS resolver, with optional static name mapping via /etc/fips/hosts.
  • Nostr-mediated discovery and NAT traversal. Peers publish endpoint adverts on public Nostr relays, exchange candidates via NIP-59 gift-wrapped offers and answers, and establish direct paths through NATs using STUN-assisted hole punching. On the local network, mDNS LAN discovery finds peers directly without relays.
  • LAN gateway. Optional fips-gateway service folds an entire unmodified LAN into the mesh: outbound (LAN clients reach mesh destinations through a DNS-allocated virtual IPv6 pool and nftables NAT) and inbound (LAN-side services exposed to the mesh through 1:1 port forwards).
  • Per-link metrics. RTT, loss, jitter, and goodput on every hop, plus mesh-size estimation, via the Metrics Measurement Protocol.
  • ECN congestion signaling. Hop-by-hop CE-flag relay with RFC 3168 IPv6 marking and transport kernel-drop detection.
  • Mesh-interface security baseline. Optional default-deny nftables policy for fips0 shipped as a packaged conffile (/etc/fips/fips.nft) with an operator drop-in directory (/etc/fips/fips.d/) and a disabled-by-default fips-firewall.service. The baseline polices only the mesh interface, leaving Docker, Tor, and the host firewall untouched.
  • Operator visibility. fipsctl CLI for control and inspection with time-series stats history queryable for any metric, fipstop TUI for live status with inline sparkline dashboards, and a JSON-line control socket on each binary for direct programmatic access.
  • Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.

Quick start

The shortest path on Debian / Ubuntu:

git clone https://github.com/jmcorgan/fips.git
cd fips
cargo install cargo-deb
cargo deb
sudo dpkg -i target/debian/fips_*.deb
sudo systemctl start fips

This installs the daemon, CLI tools (fipsctl, fipstop), the optional fips-gateway service, systemd units, and a default /etc/fips/fips.yaml you can edit before starting.

For macOS, Windows, OpenWrt, the systemd tarball, a Nix flake, or a from-source build, see docs/getting-started.md for the full multi-platform installation guide.

To join a live mesh and reach your first peer, follow the new-user tutorial progression starting at docs/tutorials/join-the-test-mesh.md.

Building from source

cargo build --release

Requires Rust 1.94.1+ (edition 2024). Linux, macOS, and Windows run as standalone daemons; Android is supported as an embedded library (the host app owns the TUN, e.g. a VpnService). Transport availability varies by platform.

Transport Linux macOS Windows Android OpenWrt
UDP
TCP
Ethernet
Tor
Nym
BLE

On Linux, a source build requires libclang — the LAN gateway's nftables bindings are generated by bindgen at build time, which needs libclang.so on the build host. Install it before building (sudo apt install libclang-dev on Debian / Ubuntu); without it the build fails inside the rustables crate with an "Unable to find libclang" error. This is a build-time prerequisite only — it is not a runtime dependency, and the pre-built .deb artifacts do not need it.

BLE is optional and, on Linux, requires BlueZ and libdbus (sudo apt install bluez libdbus-1-dev on Debian / Ubuntu). It is gated on a build-script probe — install the dependencies first and the cargo build line above picks it up. The OpenWrt ipk omits BLE because libdbus is not available on the target.

Nym (mixnet) transport builds on all desktop platforms. The OpenWrt is provisional, pending verification of nym-socks5-client availability on the target; it will flip to only if confirmed buildable there.

Alternatively, the repo ships a Nix flake: nix develop drops you into a shell with the pinned toolchain and every build prerequisite (libclang, dbus, pkg-config) already provided, and nix build .#fips builds all four binaries with no host setup. See the Nix / NixOS section of packaging/README.md.

Documentation

docs/ is organised by reader purpose:

  • Tutorials — hand-held walk-throughs from a fresh install through to a participating mesh node, plus advanced deployments (gateway on OpenWrt, hosting services, ground-up two-device mesh).
  • How-to guides — operator recipes for specific tasks: firewall activation, Nostr discovery, Tor onion service, Bluetooth peering, LAN gateway deployment and troubleshooting, MTU diagnostics, host aliases, persistent identity, unprivileged-user setup, UDP buffer tuning.
  • Referencefips.yaml configuration, wire formats, control-socket protocol, CLI references for each binary, security posture matrix, Nostr events catalog, transport statistics inventory.
  • Design — protocol-level architecture and layer specifications. Start with fips-concepts.md for the framing, then fips-architecture.md for the protocol stack.

If you want to contribute, see CONTRIBUTING.md and testing/README.md.

Examples

  • examples/sidecar-nostr-relay/ — Run a strfry Nostr relay reachable exclusively over the FIPS mesh. The relay container shares the FIPS sidecar's network namespace and is isolated from the host network.
  • examples/sidecar-nostr-mixnet-relay/ — Single-container demo of FIPS peering through a mixnet (implemented with Nym): the FIPS daemon, the mixnet proxy, and a strfry Nostr relay all in one isolated container, with the direct route to the peer firewalled off so traffic provably crosses the mixnet.
  • examples/k8s-sidecar/ — Run FIPS as a Kubernetes Pod sidecar. The sidecar creates fips0 in the Pod's shared network namespace so every other container in the Pod gets mesh access without modification.
  • examples/wireguard-sidecar-macos/ — Reach the FIPS mesh from a macOS host through a local Docker container over a WireGuard tunnel. Only traffic destined for fd00::/8 transits the sidecar; regular internet traffic continues to use the host network.

Project structure

src/          Rust source: library + fips, fipsctl, fipstop, fips-gateway binaries
docs/         Documentation: tutorials, how-to, reference, design
packaging/    Debian, macOS .pkg, Windows ZIP, OpenWrt ipk, AUR, systemd tarball
examples/     Deployment examples (Nostr relay, K8s sidecar, macOS WireGuard)
testing/      Docker-based integration test harnesses + chaos simulation

Status & roadmap

FIPS is at v0.6.0-dev on the next branch. v0.4.1 has shipped from master; this development line carries wire-format-breaking work for v0.6.0 — unified Noise XX handshake at both layers, FMP node profiles, slimmer MMP reports, and an extensible bloom-filter encoding — that will not interoperate with v0.2.x, v0.3.x, or v0.4.x peers. The core protocol works end-to-end over UDP, TCP, Ethernet, Tor, Nym, and Bluetooth on a global, public test mesh of thousands of nodes. See the CHANGELOG ## Breaking section for the full list of v0.6.0 wire-format changes in flight.

What works today

  • Spanning-tree construction with greedy coordinate routing.
  • Bloom-filter-guided destination discovery (no flooding, single-path with retry).
  • Two-layer Noise XX encryption (hop-by-hop at the link layer and end-to-end at the session layer) with periodic hitless rekey for forward secrecy at both layers and protocol negotiation in the handshake.
  • Persistent or ephemeral node identity with key-file management.
  • IPv6 TUN adapter with built-in .fips DNS resolver and multi-backend auto-configuration (systemd dns-delegate, systemd-resolved, dnsmasq, NetworkManager).
  • Static hostname mapping (/etc/fips/hosts) with auto-reload.
  • Per-link metrics (RTT, loss, jitter, goodput) and mesh size estimation.
  • ECN congestion signaling (hop-by-hop CE relay, IPv6 CE marking, kernel-drop detection).
  • UDP, TCP, Ethernet, Tor, Nym (mixnet), and BLE transports (BLE via L2CAP CoC with per-link MTU negotiation).
  • Nostr-mediated overlay endpoint discovery and UDP hole punching for NAT traversal, plus mDNS LAN discovery for local peers.
  • LAN gateway (fips-gateway) with both outbound (LAN-to-mesh) and inbound (mesh-to-LAN port-forwarding) modes.
  • Peer ACL: per-npub allow / deny admission control at the link layer; opt-in mesh-firewall baseline at fips0 ingress.
  • Runtime inspection and peer management via fipsctl and fipstop.
  • Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.
  • Linux (Debian, systemd tarball, OpenWrt, AUR), macOS (.pkg), and Windows (ZIP, service) packaging.
  • Docker-based integration and chaos testing.

Near-term priorities

  • Native API for FIPS-aware applications (npub:port addressing without the IPv6-shim path).
  • Security audit of the cryptographic protocols.

Longer-term

  • Mobile platform support.
  • Bandwidth-aware routing and QoS.
  • Protocol stability and a versioned wire format.
  • Published crate.

License

MIT — see LICENSE.

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