bf117df0ca
Implement periodic full rekey at both protocol layers using fresh DH key exchanges. Uses the existing K-bit flag (FLAG_KEY_EPOCH / FSP_FLAG_K) to coordinate cutover between peers. FMP layer (IK pattern): - ActivePeer gains rekey state: pending/previous sessions, K-bit epoch tracking, drain window, dampening timer - Handshake state stored on ActivePeer with msg1 sent on existing link - Encrypted frame handler detects K-bit flips, promotes pending sessions, falls back to previous session during drain - Handshake handlers distinguish rekey from new connections using addr_to_link lookup with identity-based fallback - Free all session indices (current, rekey, pending, previous) on peer removal FSP layer (XK pattern): - SessionEntry gains parallel rekey fields with XK-specific state for the 3-message handshake - Route availability check before FSP rekey initiation - Encrypted session handler adds K-bit flip detection and dual-session decrypt fallback - SessionSetup/Ack/Msg3 handlers extended for rekey paths Defense-in-depth: - Consecutive decryption failure detector (threshold=20) triggers forced peer removal instead of waiting for link-dead timeout - Identity-based rekey detection as fallback when addr_to_link doesn't match (e.g., TCP ephemeral ports) Configuration: RekeyConfig with enabled flag, after_secs (default 120), and after_messages (default 65536) thresholds. Logging: info for successful K-bit cutover completions, warn for failures, debug for intermediate handshake steps, trace for routine operations (resends, drain cleanup). Rekey lifecycle: 1. Timer/counter fires -> initiator starts new handshake 2. Old session continues handling traffic during handshake 3. Handshake completes -> initiator cuts over, flips K-bit 4. Responder sees flipped K-bit -> promotes new session 5. Both keep old session for 10s drain window 6. After drain, old session discarded Integration test: Docker-based multi-phase test exercising both FMP and FSP rekey with aggressive timers (35s). Verifies connectivity across all 20 directed pairs survives two consecutive rekey cycles. Includes rekey topology, docker-compose profile, and CI matrix entry. Increase ping test convergence wait from 3s to 5s for CI reliability.
FIPS Testing
Integration and simulation test harnesses for FIPS, using Docker containers running the full protocol stack.
Test Harnesses
static/ -- Static Docker Network
Fixed topologies with manual scripts for building, config generation, connectivity tests (ping, iperf), and network impairment (netem). Useful for deterministic debugging and validating specific topology configurations.
| Topology | Nodes | Transport | Description |
|---|---|---|---|
| mesh | 5 | UDP | Sparse mesh, 6 links, multi-hop |
| chain | 5 | UDP | Linear chain, max 4-hop paths |
| mesh-public | 5+1 | UDP | Mesh with external public node |
| tcp-chain | 3 | TCP | Linear chain over TCP (port 443) |
chaos/ -- Stochastic Simulation
Automated network testing with configurable node counts, topology algorithms (random geometric, Erdos-Renyi, chain, explicit), and fault injection (netem mutation, link flaps, traffic generation, node churn). 16 scenarios covering general stress testing, cost-based parent selection, mixed link technologies (fiber/Bluetooth/WiFi), and transport-specific validation (UDP, TCP, Ethernet). Scenarios are defined in YAML and executed via a Python harness that manages the full lifecycle: topology generation, Docker orchestration, fault scheduling, log collection, and analysis.