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* Gate connected-link trust on a secure session; deny forged direct announces the connected shortcut
Residual gap after the rotation-heal containment (#1401): "verified
direct" announces prove the signature but not directness — TTL is
unsigned — so a malicious connected peer can replay a victim's fresh
announce with its TTL restored. When the victim has no live link, the
replayer's link rebinds to the victim's ID and reads as "connected",
and MessageRouter's connected fast-path then trusts it outright: every
DM stalls on a Noise handshake the replayer can never complete and is
silently lost while showing "sent".
Router-level trust gate (no wire change):
- Transport gains canDeliverSecurely(to:) — BLE answers with an
established Noise session; Nostr keeps its prompt-delivery predicate;
the protocol default forwards to canDeliverPromptly for transports
without a forgeable link layer.
- MessageRouter.sendPrivate only trusts a connected link outright when
it can deliver securely; otherwise it still sends (kicking the
handshake on a genuine link) but retains a copy and hands a sealed
copy to couriers, like the reachable path. flushOutbox gets the same
gate so a flush over an insecure link resends instead of dropping the
retained copy.
Presence hardening (defense in depth): a "direct" announce arriving on
a link already bound to a different peer no longer shortcuts the
claimed peer into "connected" — only real link state does. Genuine
first-contact and direct announces are unaffected; only the ambiguous
heal path loses the forgeable shortcut.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* Harden the insecure-link outbox bound; document the second-replay presence gap and the courier metadata tradeoff
Review follow-ups on the canDeliverSecurely gate:
- flushOutbox no longer counts connected-but-insecure flushes toward the
maxSendAttempts drop: the message was actually transmitted over a live
link, so a peer whose Noise handshake stalls across reconnect flapping
must not burn through the cap and lose the store-and-forward copy the
gate exists to preserve. Retention stays bounded by the 24h outbox TTL
and the per-peer FIFO cap; acks still clear it. Attempt-counting stays
for reachable-only (heuristic) sends. Regression test: >8 connected-
insecure flushes keep the retained copy, drop callback never fires.
- Document the known second-replay presence gap: linkBoundToOtherPeer
reads the binding before rebindLinkAfterVerifiedDirectAnnounce steals
the link, so once a first replay has rebound a link to an absent
victim's ID, a second replay marks the victim connected. Presence
display only — DMs stay on the retain+courier path via the router
gate. Not closed at the announce layer because the post-rebind state
is indistinguishable from a legitimate rotation/reconnect heal (a
supported, field-verified flow). Covered by a two-announce test.
- Note the accepted courier-spray metadata tradeoff at the connected-
insecure send: nearby verified peers receive a sealed copy (they learn
a DM exists, never its content), cleared on ack.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* Promote a healed rotation to connected; normalize the secure-delivery probe; retain Codable properties in Periphery
Codex review follow-ups on 5017c232:
- P1: a legitimate rotation announce necessarily arrives on a link still
bound to the OLD peer ID, so the linkBoundToOtherPeer denial stored the
new identity as disconnected — and the rebind only fixed link state,
never the registry. A healed rotation then read as disconnected until
the peer happened to announce again. rebindLinkAfterVerifiedDirect-
Announce now promotes the rebound identity to connected after the
containment checks pass (registry markConnected + topology/snapshot/
peer-list refresh; the .peerConnected UI event already fired from the
announce path). This consciously moves the forged-presence residue
from second-replay to first-successful-rebind — bounded by the rebind
containment (never steals a live identity, one rebind per link per
cooldown) and still display-only: DMs stay gated on canDeliverSecurely.
Comments and the pinned tests updated; new regression test covers
rotate-on-open-link -> rebind -> isPeerConnected(new) == true.
- P2: BLEService.canDeliverSecurely probed the Noise session with the
peer ID as given, but sessions are keyed by the short wire ID — a send
keyed by the full 64-hex Noise key (favorites resolution) misread an
established session as insecure and needlessly retained + couriered
every DM until ack. Normalize with toShort() like isPeerConnected.
Test drives a real XX handshake and asserts both ID forms pass.
- Periphery: the PrekeyBundleStore.StoredBundle.noiseKey "assign-only"
flake fired again and slipped past its baselined USR (read exists in
loadFromDisk; the indexer intermittently misses it). Replace the
baseline entry with retain_codable_properties: true — deterministic,
and a truly-dead Codable field is a persisted-format change anyway.
Local periphery scan --strict: no unused code detected.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---------
Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Test Harness Guide
This test suite uses an in-memory networking harness to make end-to-end and integration tests deterministic, fast, and race-free without touching production code.
In-Memory Bus
- File:
bitchatTests/Mocks/MockBLEService.swift - Registry/Adjacency: Global
registrymapspeerIDto aMockBLEServiceinstance;adjacencyrecords simulated links between peers. - Setup: Call
MockBLEService.resetTestBus()insetUp()to clear state between tests. - Topology: Use
simulateConnectedPeer(_:)andsimulateDisconnectedPeer(_:)to add/remove links.connectFullMesh()helpers in tests build larger topologies. - Handlers: Tests can observe data via
messageDeliveryHandler(decodedBitchatMessage) andpacketDeliveryHandler(rawBitchatPacket). - De‑duplication: A thread-safe
seenMessageIDsprevents duplicate deliveries during flooding/relays.
Broadcast Flooding
- Flag:
MockBLEService.autoFloodEnabled - Intent: When
true, public broadcasts propagate across the entire connected component (ignores TTL for reach) while still de‑duping to prevent loops. - Usage: Enabled in Integration tests (
setUp) to simulate large-network broadcast; disabled in E2E tests to keep routing explicit and verify TTL behavior (seePublicChatE2ETests.testZeroTTLNotRelayed).
Rehandshake Flow (Noise)
- Why: The legacy NACK recovery path was removed; recovery now relies on Noise session rehandshake after decrypt failure or desync.
- Manager:
NoiseSessionManagermanages per-peer sessions. - Pattern: On decrypt failure, proactively clear the local session and re-initiate a handshake. The peer accepts and replaces their session.
- Test:
IntegrationTests.testRehandshakeAfterDecryptionFailure- Corrupts ciphertext to induce a decrypt error.
- Calls
removeSession(for:)on the initiator’s manager beforeinitiateHandshake(with:)to avoidalreadyEstablished. - Verifies encrypt/decrypt succeeds post-rehandshake.
Tips
- Determinism: Add small async delays only where handler installation/topology changes could race the first send.
- Scoping: Keep
autoFloodEnabledtoggled only within Integration tests; always reset intearDown()to avoid cross-test contamination. - Direct vs Relay: Private messages target a specific peer when adjacent; otherwise they are surfaced to neighbors for relay and, if known, also delivered to the target.
Quick Start
- Create nodes and connect them:
let svc = MockBLEService(); svc.myPeerID = "PEER1"svc.simulateConnectedPeer("PEER2")
- Observe messages:
svc.messageDeliveryHandler = { msg in /* asserts */ }
- Enable broadcast flooding for Integration suites only:
MockBLEService.autoFloodEnabled = true