Matrix: gate verification notices on DM access

jacobtomlinson · jacobtomlinson · commit 4af5fa0a2196 · 2026-03-26T11:39:16.000Z
diff --git a/extensions/matrix/src/matrix/monitor/events.test.ts b/extensions/matrix/src/matrix/monitor/events.test.ts
@@ -24,6 +24,10 @@ function createHarness(params?: {
   cryptoAvailable?: boolean;
   selfUserId?: string;
   selfUserIdError?: Error;
+  allowFrom?: string[];
+  dmEnabled?: boolean;
+  dmPolicy?: "open" | "pairing" | "allowlist" | "disabled";
+  storeAllowFrom?: string[];
   joinedMembersByRoom?: Record<string, string[]>;
   verifications?: Array<{
     id: string;
@@ -67,6 +71,7 @@ function createHarness(params?: {
   const logger = { info: vi.fn(), warn: vi.fn(), error: vi.fn() };
   const formatNativeDependencyHint = vi.fn(() => "install hint");
   const logVerboseMessage = vi.fn();
+  const readStoreAllowFrom = vi.fn(async () => params?.storeAllowFrom ?? []);
   const client = {
     on: vi.fn((eventName: string, listener: (...args: unknown[]) => void) => {
       listeners.set(eventName, listener);
@@ -101,6 +106,10 @@ function createHarness(params?: {
       accountId: params?.accountId ?? "default",
       encryption: params?.authEncryption ?? true,
     } as MatrixAuth,
+    allowFrom: params?.allowFrom ?? [],
+    dmEnabled: params?.dmEnabled ?? true,
+    dmPolicy: params?.dmPolicy ?? "open",
+    readStoreAllowFrom,
     directTracker: {
       invalidateRoom,
     },
@@ -123,6 +132,7 @@ function createHarness(params?: {
     invalidateRoom,
     roomEventListener,
     listVerifications,
+    readStoreAllowFrom,
     logger,
     formatNativeDependencyHint,
     logVerboseMessage,
@@ -255,6 +265,112 @@ describe("registerMatrixMonitorEvents verification routing", () => {
     expect(body).toContain('Open "Verify by emoji"');
   });
 
+  it("blocks verification request notices when dmPolicy pairing would block the sender", async () => {
+    const { onRoomMessage, sendMessage, roomMessageListener, logVerboseMessage } = createHarness({
+      dmPolicy: "pairing",
+    });
+    if (!roomMessageListener) {
+      throw new Error("room.message listener was not registered");
+    }
+
+    roomMessageListener("!room:example.org", {
+      event_id: "$req-pairing-blocked",
+      sender: "@alice:example.org",
+      type: EventType.RoomMessage,
+      origin_server_ts: Date.now(),
+      content: {
+        msgtype: "m.key.verification.request",
+        body: "verification request",
+      },
+    });
+
+    await vi.waitFor(() => {
+      expect(logVerboseMessage).toHaveBeenCalledWith(
+        expect.stringContaining("blocked verification sender @alice:example.org"),
+      );
+    });
+    expect(sendMessage).not.toHaveBeenCalled();
+    expect(onRoomMessage).not.toHaveBeenCalled();
+  });
+
+  it("allows verification notices for pairing-authorized DM senders from the allow store", async () => {
+    const { sendMessage, roomMessageListener, readStoreAllowFrom } = createHarness({
+      dmPolicy: "pairing",
+      storeAllowFrom: ["@alice:example.org"],
+    });
+    if (!roomMessageListener) {
+      throw new Error("room.message listener was not registered");
+    }
+
+    roomMessageListener("!room:example.org", {
+      event_id: "$req-pairing-allowed",
+      sender: "@alice:example.org",
+      type: EventType.RoomMessage,
+      origin_server_ts: Date.now(),
+      content: {
+        msgtype: "m.key.verification.request",
+        body: "verification request",
+      },
+    });
+
+    await vi.waitFor(() => {
+      expect(sendMessage).toHaveBeenCalledTimes(1);
+    });
+    expect(readStoreAllowFrom).toHaveBeenCalled();
+  });
+
+  it("does not consult the allow store when dmPolicy is open", async () => {
+    const { sendMessage, roomMessageListener, readStoreAllowFrom } = createHarness({
+      dmPolicy: "open",
+    });
+    if (!roomMessageListener) {
+      throw new Error("room.message listener was not registered");
+    }
+
+    roomMessageListener("!room:example.org", {
+      event_id: "$req-open-policy",
+      sender: "@alice:example.org",
+      type: EventType.RoomMessage,
+      origin_server_ts: Date.now(),
+      content: {
+        msgtype: "m.key.verification.request",
+        body: "verification request",
+      },
+    });
+
+    await vi.waitFor(() => {
+      expect(sendMessage).toHaveBeenCalledTimes(1);
+    });
+    expect(readStoreAllowFrom).not.toHaveBeenCalled();
+  });
+
+  it("blocks verification notices when Matrix DMs are disabled", async () => {
+    const { sendMessage, roomMessageListener, logVerboseMessage } = createHarness({
+      dmEnabled: false,
+    });
+    if (!roomMessageListener) {
+      throw new Error("room.message listener was not registered");
+    }
+
+    roomMessageListener("!room:example.org", {
+      event_id: "$req-dm-disabled",
+      sender: "@alice:example.org",
+      type: EventType.RoomMessage,
+      origin_server_ts: Date.now(),
+      content: {
+        msgtype: "m.key.verification.request",
+        body: "verification request",
+      },
+    });
+
+    await vi.waitFor(() => {
+      expect(logVerboseMessage).toHaveBeenCalledWith(
+        expect.stringContaining("blocked verification sender @alice:example.org"),
+      );
+    });
+    expect(sendMessage).not.toHaveBeenCalled();
+  });
+
   it("posts ready-stage guidance for emoji verification", async () => {
     const { sendMessage, roomEventListener } = createHarness();
     roomEventListener("!room:example.org", {
@@ -423,6 +539,51 @@ describe("registerMatrixMonitorEvents verification routing", () => {
     expect(body).toContain("SAS decimal: 6158 1986 3513");
   });
 
+  it("blocks summary SAS notices when dmPolicy allowlist would block the sender", async () => {
+    const { sendMessage, verificationSummaryListener, logVerboseMessage } = createHarness({
+      dmPolicy: "allowlist",
+      joinedMembersByRoom: {
+        "!dm:example.org": ["@alice:example.org", "@bot:example.org"],
+      },
+    });
+    if (!verificationSummaryListener) {
+      throw new Error("verification.summary listener was not registered");
+    }
+
+    verificationSummaryListener({
+      id: "verification-blocked-summary",
+      roomId: "!dm:example.org",
+      otherUserId: "@alice:example.org",
+      isSelfVerification: false,
+      initiatedByMe: false,
+      phase: 3,
+      phaseName: "started",
+      pending: true,
+      methods: ["m.sas.v1"],
+      canAccept: false,
+      hasSas: true,
+      sas: {
+        decimal: [6158, 1986, 3513],
+        emoji: [
+          ["🎁", "Gift"],
+          ["🌍", "Globe"],
+          ["🐴", "Horse"],
+        ],
+      },
+      hasReciprocateQr: false,
+      completed: false,
+      createdAt: new Date("2026-02-25T21:42:54.000Z").toISOString(),
+      updatedAt: new Date("2026-02-25T21:42:55.000Z").toISOString(),
+    });
+
+    await vi.waitFor(() => {
+      expect(logVerboseMessage).toHaveBeenCalledWith(
+        expect.stringContaining("blocked verification sender @alice:example.org"),
+      );
+    });
+    expect(sendMessage).not.toHaveBeenCalled();
+  });
+
   it("posts SAS notices from summary updates using the room mapped by earlier flow events", async () => {
     const { sendMessage, roomEventListener, verificationSummaryListener } = createHarness({
       joinedMembersByRoom: {
diff --git a/extensions/matrix/src/matrix/monitor/events.ts b/extensions/matrix/src/matrix/monitor/events.ts
@@ -34,6 +34,10 @@ export function registerMatrixMonitorEvents(params: {
   cfg: CoreConfig;
   client: MatrixClient;
   auth: MatrixAuth;
+  allowFrom: string[];
+  dmEnabled: boolean;
+  dmPolicy: "open" | "pairing" | "allowlist" | "disabled";
+  readStoreAllowFrom: () => Promise<string[]>;
   directTracker?: {
     invalidateRoom: (roomId: string) => void;
   };
@@ -48,6 +52,10 @@ export function registerMatrixMonitorEvents(params: {
     cfg,
     client,
     auth,
+    allowFrom,
+    dmEnabled,
+    dmPolicy,
+    readStoreAllowFrom,
     directTracker,
     logVerboseMessage,
     warnedEncryptedRooms,
@@ -58,6 +66,10 @@ export function registerMatrixMonitorEvents(params: {
   } = params;
   const { routeVerificationEvent, routeVerificationSummary } = createMatrixVerificationEventRouter({
     client,
+    allowFrom,
+    dmEnabled,
+    dmPolicy,
+    readStoreAllowFrom,
     logVerboseMessage,
   });
 
diff --git a/extensions/matrix/src/matrix/monitor/index.ts b/extensions/matrix/src/matrix/monitor/index.ts
@@ -266,6 +266,17 @@ export async function monitorMatrixProvider(opts: MonitorMatrixOpts = {}): Promi
       cfg,
       client,
       auth,
+      allowFrom,
+      dmEnabled,
+      dmPolicy,
+      readStoreAllowFrom: async () =>
+        await core.channel.pairing
+          .readAllowFromStore({
+            channel: "matrix",
+            env: process.env,
+            accountId: account.accountId,
+          })
+          .catch(() => []),
       directTracker,
       logVerboseMessage,
       warnedEncryptedRooms,
diff --git a/extensions/matrix/src/matrix/monitor/verification-events.ts b/extensions/matrix/src/matrix/monitor/verification-events.ts
@@ -1,6 +1,7 @@
 import { inspectMatrixDirectRooms } from "../direct-management.js";
 import { isStrictDirectRoom } from "../direct-room.js";
 import type { MatrixClient } from "../sdk.js";
+import { resolveMatrixMonitorAccessState } from "./access-state.js";
 import type { MatrixRawEvent } from "./types.js";
 import { EventType } from "./types.js";
 import {
@@ -309,8 +310,51 @@ async function sendVerificationNotice(params: {
   }
 }
 
+async function isVerificationNoticeAuthorized(params: {
+  senderId: string;
+  allowFrom: string[];
+  dmEnabled: boolean;
+  dmPolicy: "open" | "pairing" | "allowlist" | "disabled";
+  readStoreAllowFrom: () => Promise<string[]>;
+  logVerboseMessage: (message: string) => void;
+}): Promise<boolean> {
+  // Verification notices are DM-only. If DM ingress is disabled, there is no
+  // policy-compatible path for posting these notices back into the room.
+  if (!params.dmEnabled || params.dmPolicy === "disabled") {
+    params.logVerboseMessage(
+      `matrix: blocked verification sender ${params.senderId} (dmPolicy=${params.dmPolicy}, dmEnabled=${String(params.dmEnabled)})`,
+    );
+    return false;
+  }
+  if (params.dmPolicy === "open") {
+    return true;
+  }
+  const storeAllowFrom = await params.readStoreAllowFrom();
+  const accessState = resolveMatrixMonitorAccessState({
+    allowFrom: params.allowFrom,
+    storeAllowFrom,
+    // Verification flows only exist in strict DMs, so room/group allowlists do
+    // not participate in the authorization decision here.
+    groupAllowFrom: [],
+    roomUsers: [],
+    senderId: params.senderId,
+    isRoom: false,
+  });
+  if (accessState.directAllowMatch.allowed) {
+    return true;
+  }
+  params.logVerboseMessage(
+    `matrix: blocked verification sender ${params.senderId} (dmPolicy=${params.dmPolicy})`,
+  );
+  return false;
+}
+
 export function createMatrixVerificationEventRouter(params: {
   client: MatrixClient;
+  allowFrom: string[];
+  dmEnabled: boolean;
+  dmPolicy: "open" | "pairing" | "allowlist" | "disabled";
+  readStoreAllowFrom: () => Promise<string[]>;
   logVerboseMessage: (message: string) => void;
 }) {
   const routerStartedAtMs = Date.now();
@@ -411,6 +455,18 @@ export function createMatrixVerificationEventRouter(params: {
       );
       return;
     }
+    if (
+      !(await isVerificationNoticeAuthorized({
+        senderId: summary.otherUserId,
+        allowFrom: params.allowFrom,
+        dmEnabled: params.dmEnabled,
+        dmPolicy: params.dmPolicy,
+        readStoreAllowFrom: params.readStoreAllowFrom,
+        logVerboseMessage: params.logVerboseMessage,
+      }))
+    ) {
+      return;
+    }
     const sasNotice = formatVerificationSasNotice(summary);
     if (!sasNotice) {
       return;
@@ -459,6 +515,18 @@ export function createMatrixVerificationEventRouter(params: {
         );
         return;
       }
+      if (
+        !(await isVerificationNoticeAuthorized({
+          senderId,
+          allowFrom: params.allowFrom,
+          dmEnabled: params.dmEnabled,
+          dmPolicy: params.dmPolicy,
+          readStoreAllowFrom: params.readStoreAllowFrom,
+          logVerboseMessage: params.logVerboseMessage,
+        }))
+      ) {
+        return;
+      }
       rememberVerificationUserRoom(senderId, roomId);
       if (!trackBounded(routedVerificationEvents, sourceFingerprint)) {
         return;
