Files
bitchat/bitchatTests
3e9230229d Heal peer-ID rotation: rebind link on verified announce, retire ghost peer (#1401)
* Heal peer-ID rotation: rebind link on verified announce, retire ghost

When a peer relaunches it rotates its ephemeral peer ID, but a
still-open BLE connection kept its stale peripheral/central→peerID
binding for the reachability retention window (~45-60s). Until it aged
out, the other side showed a duplicate ghost peer and dropped the
rotated peer's direct announces as spoofing attempts.

Root cause: the ingress guard rejected a direct announce whose claimed
sender differed from the link binding before signature verification
could ever see it, so the binding could never heal.

- Ingress guard: let a mismatched direct announce through, attributed
  to the claimed sender; REQUEST_SYNC keeps the strict binding check.
- Bind sites: raw (pre-verification) announces may only bind unbound
  links, never rebind bound ones — rebinding now requires the announce
  handler's signature verification to pass.
- On a verified direct announce whose ingress link is bound to a
  different peer, rebind the link to the announced ID and retire the
  rotated-away ID immediately (registry + gossip + UI), mirroring
  handleLeave.
- BLELinkStateStore.bindPeripheral: drop the previous peer's reverse
  mapping on rebind so the retired ID no longer claims the link.

Fixes #1387

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

* Contain forged-directness rebinds: no identity steal, per-link cooldown

The announce signature does not authenticate directness (TTL is
excluded from signing because relays mutate it), so a bound peer could
replay another peer's fresh signed announce with its TTL restored and
reach the rotation rebind path. Contain what such a replay can do:

- Refuse a rebind when the claimed identity already owns another live
  link — a replayed announce can no longer steal a connected peer's
  binding or route its directed traffic to the replaying link.
- Allow at most one rebind per link per cooldown window (60s) so two
  identities cannot fight over a link in a replay flip-flop, with each
  flip retiring the other peer.

A replay against an identity with no live link remains possible, but
that capability already exists today on unbound links, where any raw
direct announce binds pre-verification.

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>
2026-07-08 10:08:23 +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