The FSP XK rekey handshake has a race condition where the initiator can cut over (K-bit flip) and send data encrypted with the new session before msg3 reaches the responder. The responder has no pending session yet, so K-bit detection fails and packets are dropped. Defer FSP initiator cutover by 2 seconds after handshake completion (FSP_CUTOVER_DELAY_MS) to give msg3 time to traverse the mesh. FMP (IK, 2 messages) is unaffected since the responder completes during msg1 processing. Also fix MMP metric corruption after rekey cutover: the new session starts with counter 0 but MMP state carries highest_counter and GapTracker.expected_next from the old session, producing false reorder counts, jitter spikes, and invalid OWD trends. Add reset_for_rekey() methods that clear counter-dependent state while preserving RTT estimates. Additional fixes: - Remove stale peers_by_index entry on abandon_rekey error path - Replace redundant peers_by_index inserts with debug assertions verifying the pre-registration invariant - Tighten rekey integration test to zero tolerance (was 4 failures)
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 8443) |
| rekey | 5 | UDP | Rekey integration test topology |
tor/ -- Tor Transport Integration
End-to-end Tor transport testing with Docker containers running real Tor daemons. Requires internet access for Tor bootstrapping.
| Scenario | Description |
|---|---|
| socks5-outbound | Outbound SOCKS5 connections through Tor to clearnet peer |
| directory-mode | Inbound via HiddenServiceDir onion service (co-located) |
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). 20 scenarios covering general stress testing, cost-based parent selection, mixed link technologies (fiber/Bluetooth/WiFi), transport-specific validation (UDP, TCP, Ethernet), and ECN/congestion testing. 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.