Files
bitchat/bitchatTests
87910541ef Prekey bundles: forward-secret async first contact for courier mail (#1381)
* Add capability bits to announce TLV

Announces now carry an optional capabilities TLV (0x05): a little-endian
bitfield with named bits for upcoming features (prekeys, wifiBulk,
gateway, groups, board, vouch, meshDiagnostics). Old clients skip the
unknown TLV; peers without it decode as nil so features can distinguish
"legacy peer" from "advertises nothing".

PeerCapabilities lives in BitFoundation with a minimal-length encoding
that preserves unknown bits for forward compatibility. Peer capabilities
are stored in the BLE peer registry on verified announce and exposed via
BLEService.peerCapabilities(_:). The local advertisement set is empty
until each feature ships its bit.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Prekey bundles: forward-secret async first contact for courier mail

Courier envelopes were sealed with one-way Noise X to the recipient's
long-lived static key, so a later compromise of that key exposed every
envelope captured in transit. This adds one-time prekey bundles:

- PrekeyBundle (MessageType 0x24): 8 one-time Curve25519 public prekeys
  bound to the owner's Noise static key by an Ed25519 signature over
  "bitchat-prekey-bundle-v1" canonical bytes; gossiped mesh-wide on its
  own 60s sync round (SyncTypeFlags bit 9, 200-peer cap, 24h freshness)
  and verified against the announce-bound signing key before caching.
- Sealed envelope v2: Noise X where the responder static is the one-time
  prekey, prologue "bitchat-prekey-v1" || prekeyID. Sender identity rides
  encrypted inside and is authenticated exactly like v1 (blocked-sender
  check included). CourierEnvelope gains an optional prekeyID TLV that
  v1 decoders skip as unknown.
- Local prekeys live in the Keychain; consumed privates survive a 48h
  grace window for spray-and-wait redeliveries, then are deleted (the
  forward-secrecy clock starts at deletion). The batch tops back up and
  re-gossips when unconsumed count drops below 3, and everything is
  wiped in panic mode.
- Routing: courier sealing picks a cached verified bundle when one
  exists (one prekey per message, reused across deposit retries), with
  the advertised .prekeys capability as a veto for on-mesh peers, and
  falls back to static sealing otherwise.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Prekeys: authenticate bundle packets, fix consume-republish, deflake CI

Fixes the prekey-bundle PR review + CI failure:

- CI root cause: the receive queue (mesh.message) is concurrent, so a
  gossiped prekey bundle can be processed before the announce that binds
  its owner's signing key. The old handler dropped such bundles outright,
  so under CI parallel load the bundle was permanently lost and the
  cache/gossip tests flaked (verifiedBundleEntersGossipStore,
  prekeySealedMailTravelsViaCourierAndOpens). Bundles that arrive before
  their binding are now retained per-owner (bounded) and re-attempted when
  the verified announce lands, atomically to avoid a check-then-act race.

- Authenticate the OUTER prekey-bundle packet (Codex P2 / review MEDIUM):
  require senderID == PeerID(bundle.noiseStaticPublicKey) and verify the
  packet's Ed25519 signature (covers senderID + timestamp) against the
  owner's bound signing key, in addition to the inner bundle signature.
  Stops replay under a fresh timestamp / fake senderID.

- Key the gossip prekey-bundle store/dedup by the bundle's authenticated
  identity (noiseStaticPublicKey), not the unauthenticated packet
  senderID, so one valid bundle sprayed under many fabricated sender IDs
  can't multiply entries and exhaust the 200-owner cap.

- Bump published-bundle generatedAt strictly on consume (Codex P1):
  consuming a prekey shrinks the published bundle, so it now republishes
  with a strictly newer generatedAt and re-gossips, so peers replace the
  cached copy and stop assigning the consumed ID before its 48h grace.

- Guard the panic/clear detached Application Support tree-deletes behind
  TestEnvironment.isRunningTests: the SPM test process shares that tree,
  so the wipe could land mid-test and flake file-dependent tests.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Update sync tests for prekeyBundle as bit 9 / default sync round

Prekeys makes bit 9 (prekeyBundle) a known SyncTypeFlags bit and enables
a prekey sync round by default. That broke tests authored by other PRs
that assumed bit 9 was phantom or that only their own sync round fires:

- SyncTypeFlags(Board)Tests: move the "unknown bits" probes to bits 10+
  (0xFE -> 0xFC / 0xFD), since bit 9 is now assigned.
- GossipSync(Board)Tests + GossipSyncManagerTests: disable the prekey sync
  round in configs that run maintenance (as they already do for message/
  fragment/fileTransfer), so they isolate the behavior under test.

Full app suite (1301 tests) green locally via SPM.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-07 15:38:33 +02:00
..

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 registry maps peerID to a MockBLEService instance; adjacency records simulated links between peers.
  • Setup: Call MockBLEService.resetTestBus() in setUp() to clear state between tests.
  • Topology: Use simulateConnectedPeer(_:) and simulateDisconnectedPeer(_:) to add/remove links. connectFullMesh() helpers in tests build larger topologies.
  • Handlers: Tests can observe data via messageDeliveryHandler (decoded BitchatMessage) and packetDeliveryHandler (raw BitchatPacket).
  • Deduplication: A thread-safe seenMessageIDs prevents 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 deduping 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 (see PublicChatE2ETests.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: NoiseSessionManager manages 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 initiators manager before initiateHandshake(with:) to avoid alreadyEstablished.
    • 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 autoFloodEnabled toggled only within Integration tests; always reset in tearDown() 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