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jackandClaude Fable 5
ca63893197
A broad audit surfaced ten critical/high issues across the crypto, transport, identity, and panic-wipe layers. This fixes all ten. Critical: - Nostr DMs were unauthenticated. The NIP-17 seal was signed with a throwaway ephemeral key and the receiver never verified it, so anyone who knows a recipient's npub could forge messages (and delivery/read receipts) into an existing trusted conversation. The seal is now signed with the sender's real identity key, and the receiver verifies the seal signature and that seal.pubkey == rumor.pubkey. NOTE: this is a breaking wire-protocol change (see PR). - Public BLE messages trusted registry membership instead of the packet signature. Since senderID is attacker-controlled, any verified peer could be impersonated in public chat. A valid signature from the claimed sender is now required before any registry identity is used. - Unverified announces still persisted the announced identity, letting a replayed noisePublicKey overwrite a victim's stored signing key and nickname. persistIdentity is now gated on verification. High: - Noise decrypt trapped on a 16-19 byte ciphertext (negative prefix length after nonce extraction) — a remote crash. Now validated. - Identity-cache debounce save used Timer.scheduledTimer on a GCD queue with no run loop, so it never fired; block/verify/favorite changes only persisted on explicit forceSave. Replaced with a DispatchSourceTimer on the queue; forceSave is now serialized. - Identity-cache key load couldn't tell "missing" from a transient keychain failure and would regenerate (deleting) the key, orphaning the cache. Now uses getIdentityKeyWithResult and falls back to a session-only ephemeral key without clobbering the persisted key/cache. - BLE receive-dedup key lacked a payload digest, so post-handshake flushes (queued msgs + delivery/read acks in the same ms) were dropped as duplicates. Digest added, matching the ingress registry. - Maintenance timer was created only in init and never recreated after a panic stop/start, silently degrading the mesh until app restart. Now recreated in startServices. - Panic wipe left persisted location state (selected channel, teleport set, bookmarks) and cached per-geohash Nostr private keys behind. Both are now cleared. - Panic spawned an orphan NostrRelayManager instead of reusing .shared, splitting relay state from every other component. Now reuses .shared. Tests updated to assert the fixed behavior (announce no longer persists unverified identities; public messages require a signature; receive dedup ID includes the payload digest). 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