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When a Noise session establishes with a peer I verified and that peer advertises the .vouch capability, send signed attestations (up to 16, most recently verified first, at most once per peer per 24h) for the OTHER fingerprints I verified. Receivers accept vouches only from senders they verified themselves, verify the Ed25519 signature against the sender's announce-bound signing key, and surface the result as a new derived trust tier: vouched (unfilled seal) between casual and trusted. Protocol: - NoisePayloadType.vouch = 0x12 carries a batch of TLV attestations: voucheeFingerprint (32B), voucheeSigningKey (32B), timestamp (uint64 ms BE), Ed25519 signature over "bitchat-vouch-v1" | fingerprint | signingKey | timestamp. The voucher is implicit in the authenticated session. - PeerCapabilities.localSupported now advertises .vouch. Storage (SecureIdentityStateManager / IdentityCache): - vouches keyed by vouchee, capped at 8 vouchers each; validity is recomputed on read (voucher still verified-by-me, < 30 days old), so unverifying a voucher retires their vouches without cascade deletes. - New IdentityCache fields are Optional so pre-existing encrypted caches decode cleanly; TrustLevel.vouched is inserted mid-ladder but raw values are strings, so persisted values are unaffected (and vouched itself is never persisted). - Panic wipe clears vouch state with the rest of the identity cache. UI: unfilled checkmark.seal badge in the mesh peer list (filled seal stays exclusive to verified) and a "vouched for by N people you verified" section with voucher names in FingerprintView; VoiceOver labels and xcstrings entries included. Tests: attestation encode/decode + signature (forged/tampered/expired), accept-policy gates, batch cap, trust-level derivation incl. voucher invalidation, persistence compat, and coordinator exchange/accept policies. Full macOS suite: 1088 tests passing. 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