mirror of
https://github.com/permissionlesstech/bitchat.git
synced 2026-07-25 00:25:19 +00:00
jackandClaude Fable 5
385d32063f
BLE announce trust verified the packet signature against the Ed25519 signing key carried inside the same announce, and the trust policy only rejected on noise-key mismatch. Since peerIDs derive from the broadcast (public) noise key, an on-mesh attacker could replay a victim's peerID+noiseKey with their own signing key, nickname, and a valid self-signature; BLEPeerRegistry.upsertVerifiedAnnounce then overwrote the victim's entry unconditionally. That enabled mesh nickname spoofing and, via the persisted identity, forged attribution of signed public/broadcast messages. Fix: TOFU-pin the signing key per peer (noise-key-derived peerID). - BLEAnnounceTrustPolicy now rejects announces whose signing key differs from the one already recorded for the peer (.signingKeyMismatch) and logs a security event. - BLEPeerRegistry.upsertVerifiedAnnounce refuses to replace a pinned signing key (returns nil), closing the race where the pre-barrier trust check reads the registry outside the collections barrier. It also never drops a pinned key when an announce omits one. - BLEAnnounceHandler skips registry upsert, topology updates, and identity persistence for rejected announces. No wire-format change: the packet signature already covers senderID, timestamp, and the full announce payload (noise key, signing key, nickname), so mixed-version meshes are unaffected. First contact for an unknown peer behaves exactly as before (trust on first use); the pin is scoped to the registry entry lifetime, so a legitimately re-keyed identity recovers after normal peer eviction. Tests: trust-policy signing-key mismatch/match cases, registry pinning (attacker upsert refused, legitimate re-announce accepted, omitted key keeps pin), handler-level pinned-key rejection, and an end-to-end test with real Ed25519 keys showing a fully self-consistent attacker announce cannot displace the victim's pinned identity. Co-Authored-By: Claude Fable 5 <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