code-pairing.test.ts

1// Code pairing — the PAIR_IDENTITY half over an address-bearing pairing code.2//3// Driven entirely through the dependency-injection seam (CodePairingDeps and a4// fake PairingSocket), so no real WebSocket or Noise crypto runs — except the5// SAS KAT, which calls the REAL `derivePairingSAS` to pin cross-implementation6// agreement with the peer.78import { beforeEach, describe, expect, it, vi } from "vitest";910import {11  pairWithCode,12  type CodePairingDeps,13  type CodePairingCallbacks,14} from "./code-pairing";15import type { PairingSocket } from "../shared/pairing-dial";1617// REAL SAS implementation — reused, not re-derived (ground truth §5).18import { derivePairingSAS } from "../shared/pairing-handshake";19import { encodePairingCode } from "../shared/pairing-code";20import type { LocalIdentity } from "../shared/pairing-handshake";21import type { PairedDevice } from "../shared/sync-types";2223// ── helpers ────────────────────────────────────────────────────────────────2425const enc = (o: unknown) => new TextEncoder().encode(JSON.stringify(o));26const dec = (b: Uint8Array) => JSON.parse(new TextDecoder().decode(b));2728const PEER_EPHEMERAL_HEX = "a".repeat(64);29const PHONE_LONGTERM_HEX = "f".repeat(64);30const PHONE_TOKEN = Uint8Array.of(0xde, 0xad, 0xbe, 0xef);31const PHONE_CODE = encodePairingCode("192.168.4.77", 51555, PHONE_TOKEN);3233const OUR_IDENTITY: LocalIdentity = {34  deviceId: "ext-local-001",35  deviceName: "Firefox on MacBook",36  deviceType: "extension",37  longTermPublicKeyHex: "c".repeat(64),38  signingPublicKeyHex: "d".repeat(64),39  vaultId: "e".repeat(64),40};4142/**43 * Scripted fake socket. Captures everything sent, and replays a queued list44 * of inbound frames. A frame of `null` means "the socket closes here with no45 * data" — the wrong-code behaviour (no error frame).46 */47function makeFakeSocket(inbound: Array<Uint8Array | null>) {48  const sent: Uint8Array[] = [];49  let closed = false;50  let lastWasClose = false;51  const queue = [...inbound];52  const sock: PairingSocket = {53    send(bytes) { sent.push(bytes); },54    async receive() {55      const next = queue.shift();56      if (next === undefined || next === null) {57        closed = true;58        lastWasClose = true;59        throw new Error("socket closed");60      }61      lastWasClose = false;62      return next;63    },64    close() { closed = true; },65    closedBeforeFrame() { return lastWasClose; },66  };67  return { sock, sent, isClosed: () => closed };68}6970/**71 * A fake Noise session that no-ops encrypt/decrypt (identity transform) so we72 * can drive the PAIR_IDENTITY exchange without real crypto. We stub73 * `noiseNKInitiator` via vi.mock below; this is the shape it returns.74 */75const FAKE_HANDSHAKE_HASH = Uint8Array.from([76  0x0f, 0xba, 0xb8, 0xcd, ...new Array(28).fill(0),77]);7879// Mock the NK initiator: skip the two handshake messages, hand back a session80// whose encrypt/decrypt are identity transforms and whose handshakeHash is the81// cross-platform KAT prefix (so the SAS test below is end-to-end through the flow).82vi.mock("../shared/noise-js", async (orig) => {83  const actual = await orig<typeof import("../shared/noise-js")>();84  return {85    ...actual,86    noiseNKInitiator: vi.fn(async (_responderStatic, _send, _receive) => ({87      encrypt: (pt: Uint8Array) => pt,88      decrypt: (ct: Uint8Array) => ct,89      handshakeHash: FAKE_HANDSHAKE_HASH,90    })),91  };92});9394function makeDeps(overrides: Partial<CodePairingDeps> = {}): {95  deps: CodePairingDeps;96  persisted: PairedDevice[];97  sockets: ReturnType<typeof makeFakeSocket>[];98} {99  const persisted: PairedDevice[] = [];100  const sockets: ReturnType<typeof makeFakeSocket>[] = [];101  const deps: CodePairingDeps = {102    openSocket: vi.fn(async () => {103      // default: ACK then a PAIR_IDENTITY response104      const s = makeFakeSocket([105        enc({ type: "PEACH_HELLO_ACK", ephemeralPublicKeyHex: PEER_EPHEMERAL_HEX }),106        enc({107          type: "PAIR_IDENTITY",108          device_id: "android-001",109          device_name: "Pixel 8",110          device_type: "android",111          long_term_public_key_hex: PHONE_LONGTERM_HEX,112          ws_port: 49142,113        }),114      ]);115      sockets.push(s);116      return s.sock;117    }),118    getLocalIdentity: vi.fn(async () => OUR_IDENTITY),119    persistDevice: vi.fn(async (d: PairedDevice) => { persisted.push(d); }),120    ...overrides,121  };122  return { deps, persisted, sockets };123}124125function makeCallbacks(): {126  cb: CodePairingCallbacks;127  sas: { value?: string };128  errors: string[];129  completed: PairedDevice[];130} {131  const sas: { value?: string } = {};132  const errors: string[] = [];133  const completed: PairedDevice[] = [];134  const cb: CodePairingCallbacks = {135    onSasReady: (s) => { sas.value = s; },136    onError: (e) => { errors.push(e); },137    onComplete: (d) => { completed.push(d); },138  };139  return { cb, sas, errors, completed };140}141142beforeEach(() => {143  vi.clearAllMocks();144});145146// ── specs ────────────────────────────────────────────────────────────────147148describe("pairWithCode", () => {149  it("dials the coded endpoint and sends its token in PEACH_HELLO", async () => {150    const { deps, sockets } = makeDeps();151    const { cb } = makeCallbacks();152153    await pairWithCode(PHONE_CODE, cb, deps, async () => true);154155    expect(deps.openSocket).toHaveBeenCalledWith("192.168.4.77", 51555);156    const firstFrame = dec(sockets[0].sent[0]);157    expect(firstFrame).toEqual({ type: "PEACH_HELLO", token: "deadbeef" });158  });159160  it("treats a socket close without PEACH_HELLO_ACK as invalid_code", async () => {161    // The listener sends NO error frame on a wrong/expired code — it SILENTLY162    // CLOSES the socket and rotates the code. So the163    // absence of a PEACH_HELLO_ACK *is* the wrong-code signal. (This replaces164    // the original brief's bogus PEACH_HELLO_ERROR test — no such frame exists.)165    const closeImmediately = makeFakeSocket([null]); // close, no data166    const { deps } = makeDeps({167      openSocket: vi.fn(async () => closeImmediately.sock),168    });169    const { cb, errors, completed } = makeCallbacks();170171    await pairWithCode(PHONE_CODE, cb, deps, async () => true);172173    expect(errors).toEqual(["invalid_code"]);174    expect(completed).toHaveLength(0);175    expect(deps.persistDevice).not.toHaveBeenCalled();176  });177178  it("derives the SAS via the real derivePairingSAS — KAT 0fbab8cd… → 895245", () => {179    // Cross-impl KAT pinned in peach-sync (pairing.zig:275-279): the handshake180    // hash beginning 0f ba b8 cd yields SAS "895245". 0x0fbab8cd = 263895245;181    // 263895245 mod 1_000_000 = 895245.182    const hash = Uint8Array.from([183      0x0f, 0xba, 0xb8, 0xcd, ...new Array(28).fill(0),184    ]);185    expect(derivePairingSAS(hash)).toBe("895245");186  });187188  it("surfaces that same SAS through the pairing flow", async () => {189    // FAKE_HANDSHAKE_HASH starts 0fbab8cd, so onSasReady must report 895245.190    const { deps } = makeDeps();191    const { cb, sas } = makeCallbacks();192193    await pairWithCode(PHONE_CODE, cb, deps, async () => true);194195    expect(sas.value).toBe("895245");196  });197198  it("persists the phone identity on SAS confirm", async () => {199    const { deps, persisted } = makeDeps();200    const { cb, completed, errors } = makeCallbacks();201202    await pairWithCode(PHONE_CODE, cb, deps, async () => true);203204    expect(errors).toHaveLength(0);205    expect(persisted).toHaveLength(1);206    expect(persisted[0].deviceType).toBe("android");207    expect(persisted[0].deviceId).toBe("android-001");208    expect(persisted[0].longTermPublicKeyHex).toBe(PHONE_LONGTERM_HEX);209    expect(persisted[0].trustSource).toBe("direct");210    expect(persisted[0].wsPort).toBe(49142);211    expect(completed).toHaveLength(1);212  });213214  it("aborts with sas_mismatch and persists nothing when the user rejects", async () => {215    const { deps, persisted } = makeDeps();216    const { cb, errors } = makeCallbacks();217218    await pairWithCode(PHONE_CODE, cb, deps, async () => false);219220    expect(errors).toEqual(["sas_mismatch"]);221    expect(persisted).toHaveLength(0);222    expect(deps.persistDevice).not.toHaveBeenCalled();223  });224225  it("includes vault_id in the outbound PAIR_IDENTITY (Change 1)", async () => {226    const { deps, sockets } = makeDeps();227    const { cb } = makeCallbacks();228229    await pairWithCode(PHONE_CODE, cb, deps, async () => true);230231    // sent[0] = PEACH_HELLO (plaintext); sent[1] = our PAIR_IDENTITY232    // (encrypt is identity in the mock, so it decodes directly).233    const ourPairIdentity = dec(sockets[0].sent[1]);234    expect(ourPairIdentity.type).toBe("PAIR_IDENTITY");235    expect(ourPairIdentity.vault_id).toBe(OUR_IDENTITY.vaultId);236  });237238  it("reports vault_locked when local identity is unavailable", async () => {239    const { deps } = makeDeps({240      getLocalIdentity: vi.fn(async () => { throw new Error("vault_locked"); }),241    });242    const { cb, errors } = makeCallbacks();243244    await pairWithCode(PHONE_CODE, cb, deps, async () => true);245246    expect(errors).toEqual(["vault_locked"]);247    expect(deps.openSocket).not.toHaveBeenCalled();248  });249});250251// ── pairing-code path (the phone is the listener) ──────────────────────────252253/** Deps whose socket replays an Android peer's ACK + PAIR_IDENTITY. */254function makePhoneDeps(deviceType: string | undefined = "android") {255  const identity: Record<string, unknown> = {256    type: "PAIR_IDENTITY",257    device_id: "android-001",258    device_name: "Pixel 8",259    long_term_public_key_hex: PHONE_LONGTERM_HEX,260    ws_port: 49142,261  };262  identity.device_type = deviceType;263  return makeDeps({264    openSocket: vi.fn(async () => makeFakeSocket([265      enc({ type: "PEACH_HELLO_ACK", ephemeralPublicKeyHex: PEER_EPHEMERAL_HEX }),266      enc(identity),267    ]).sock),268  });269}270271describe("pairWithCode — pairing code", () => {272  it("dials the address in the code", async () => {273    const { deps } = makePhoneDeps();274    const { cb, errors } = makeCallbacks();275276    await pairWithCode(PHONE_CODE, cb, deps, async () => true);277278    expect(errors).toHaveLength(0);279    expect(deps.openSocket).toHaveBeenCalledWith("192.168.4.77", 51555);280  });281282  it("presents the token as hex in the plaintext hello, not a 6-digit code", async () => {283    const sockets: ReturnType<typeof makeFakeSocket>[] = [];284    const { deps } = makeDeps({285      openSocket: vi.fn(async () => {286        const s = makeFakeSocket([287          enc({ type: "PEACH_HELLO_ACK", ephemeralPublicKeyHex: PEER_EPHEMERAL_HEX }),288          enc({289            type: "PAIR_IDENTITY",290            device_id: "android-001",291            device_name: "Pixel 8",292            device_type: "android",293            long_term_public_key_hex: PHONE_LONGTERM_HEX,294            ws_port: 49142,295          }),296        ]);297        sockets.push(s);298        return s.sock;299      }),300    });301    const { cb } = makeCallbacks();302303    await pairWithCode(PHONE_CODE, cb, deps, async () => true);304305    const hello = dec(sockets[0].sent[0]);306    expect(hello.type).toBe("PEACH_HELLO");307    expect(hello.token).toBe("deadbeef");308    expect(hello.code).toBeUndefined();309  });310311  it("persists the phone with the device type it announced", async () => {312    const { deps, persisted } = makePhoneDeps();313    const { cb, completed } = makeCallbacks();314315    await pairWithCode(PHONE_CODE, cb, deps, async () => true);316317    expect(persisted).toHaveLength(1);318    expect(persisted[0].deviceType).toBe("android");319    expect(persisted[0].deviceId).toBe("android-001");320    expect(persisted[0].longTermPublicKeyHex).toBe(PHONE_LONGTERM_HEX);321    expect(persisted[0].trustSource).toBe("direct");322    expect(persisted[0].wsPort).toBe(49142);323    expect(completed).toHaveLength(1);324  });325326  it("rejects a peer that omits its device type", async () => {327    const { deps, persisted } = makePhoneDeps("");328    const { cb, errors } = makeCallbacks();329330    await pairWithCode(PHONE_CODE, cb, deps, async () => true);331332    expect(errors).toEqual(["handshake_failed"]);333    expect(persisted).toHaveLength(0);334  });335336  it("caches the coded IP for the next sync round", async () => {337    const cacheLastKnownIp = vi.fn(async () => undefined);338    const { deps } = makePhoneDeps();339    deps.cacheLastKnownIp = cacheLastKnownIp;340    const { cb } = makeCallbacks();341342    await pairWithCode(PHONE_CODE, cb, deps, async () => true);343344    expect(cacheLastKnownIp).toHaveBeenCalledWith(PHONE_LONGTERM_HEX, "192.168.4.77");345  });346347  it("reports no_host_found when the coded endpoint refuses the connection", async () => {348    const { deps } = makeDeps({349      openSocket: vi.fn(async () => { throw new Error("ECONNREFUSED"); }),350    });351    const { cb, errors } = makeCallbacks();352353    await pairWithCode(PHONE_CODE, cb, deps, async () => true);354355    expect(errors).toEqual(["no_host_found"]);356    expect(deps.persistDevice).not.toHaveBeenCalled();357  });358359  it("still aborts on SAS rejection — the token is not the security boundary", async () => {360    const { deps, persisted } = makePhoneDeps();361    const { cb, errors } = makeCallbacks();362363    await pairWithCode(PHONE_CODE, cb, deps, async () => false);364365    expect(errors).toEqual(["sas_mismatch"]);366    expect(persisted).toHaveLength(0);367  });368});