Bot review (CodeRabbit, cubic) on PR #7098 surfaced several real defects:
- Strict() parsed the raw env value instead of the normalized one, so a
mixed-case NB_PQ_MLKEM_STRICT such as "tRuE" silently disabled fail-closed
mode. Parse the lower-cased value, matching Enabled().
- OnDataPathMessage labeled a data-path answer as "signal" in logs, mislabeling
every rotation answer. Use the data-path label.
- A failed sendAnswer aborted the whole connection setup, skipping the relay/ICE
listeners; a transient signalling failure now still brings the local transport
up (the peer retries the answer).
- processOffer left the reserved exchange slot in place when Respond failed, so
every retransmission of that offer was dropped forever. Clear the reservation
on a pre-commit error so a retry can derive again.
- Dropped a no-op time.Since that implied a convergence-latency metric that was
never recorded, and the now-unused startedAt field.
- The strict-mode status line asserted active blocking even for a peer that is
simply offline; reword it to state that no PSK is established yet.
- conn_test used t.Fatalf for conditions under test; use assert.
Strict mode (NB_PQ_MLKEM_STRICT, default off) closes the initial PQ-vulnerable
window (NET-1408): when enabled, conn.presharedKey programs a per-conn random
sentinel PSK until the ML-KEM exchange derives the real one, so no session can form
on a non-PQ key (the real PSK is pushed via SetPresharedKey once it converges).
Default stays opportunistic.
Also surface PQ status: the peer 'Quantum resistance' flag (RosenpassEnabled) is now
true when an ML-KEM PSK has been derived for the peer, not only for Rosenpass.
- Add a trace slog level (NB_PQ_MLKEM_LOG_LEVEL=trace) and move the verbose
per-exchange lifecycle logs (offer/answer/PSK/ack/rotation) to it, so debug
stays quiet and troubleshooting is opt-in.
- Stop logging the raw preshared key; drop the temporary pqkem-dbg OnRemoteOffer/
OnRemoteAnswer probes.
- Demote the per-handshake conn log to trace.
riccardom