verify cross-signing key with SAS

spec/unit/crypto/verification/sas.spec.js

@@ -22,6 +22,7 @@ try {
 }
 
 import expect from 'expect';
+import olmlib from '../../../../lib/crypto/olmlib';
 
 import sdk from '../../../..';
 
@@ -78,38 +79,35 @@ describe("SAS verification", function() {
                 },
             );
 
-            alice.setDeviceVerified = expect.createSpy();
-            alice.getDeviceEd25519Key = () => {
-                return "alice+base64+ed25519+key";
-            };
-            alice.getStoredDevice = () => {
-                return DeviceInfo.fromStorage(
-                    {
-                        keys: {
-                            "ed25519:Dynabook": "bob+base64+ed25519+key",
-                        },
+            const aliceDevice = alice._crypto._olmDevice;
+            const bobDevice = bob._crypto._olmDevice;
+
+            alice._crypto._deviceList.storeDevicesForUser("@bob:example.com", {
+                Dynabook: {
+                    user_id: "@bob:example.com",
+                    device_id: "Dynabook",
+                    algorithms: [olmlib.OLM_ALGORITHM, olmlib.MEGOLM_ALGORITHM],
+                    keys: {
+                        "ed25519:Dynabook": bobDevice.deviceEd25519Key,
+                        "curve25519:Dynabook": bobDevice.deviceCurve25519Key,
                     },
-                    "Dynabook",
-                );
-            };
+                },
+            });
             alice.downloadKeys = () => {
                 return Promise.resolve();
             };
 
-            bob.setDeviceVerified = expect.createSpy();
-            bob.getStoredDevice = () => {
-                return DeviceInfo.fromStorage(
-                    {
-                        keys: {
-                            "ed25519:Osborne2": "alice+base64+ed25519+key",
-                        },
+            bob._crypto._deviceList.storeDevicesForUser("@alice:example.com", {
+                Osborne2: {
+                    user_id: "@alice:example.com",
+                    device_id: "Osborne2",
+                    algorithms: [olmlib.OLM_ALGORITHM, olmlib.MEGOLM_ALGORITHM],
+                    keys: {
+                        "ed25519:Osborne2": aliceDevice.deviceEd25519Key,
+                        "curve25519:Osborne2": aliceDevice.deviceCurve25519Key,
                     },
-                    "Osborne2",
-                );
-            };
-            bob.getDeviceEd25519Key = () => {
-                return "bob+base64+ed25519+key";
-            };
+                },
+            });
             bob.downloadKeys = () => {
                 return Promise.resolve();
             };
@@ -180,10 +178,12 @@ describe("SAS verification", function() {
             expect(macMethod).toBe("hkdf-hmac-sha256");
 
             // make sure Alice and Bob verified each other
-            expect(alice.setDeviceVerified)
-                .toHaveBeenCalledWith(bob.getUserId(), bob.deviceId);
-            expect(bob.setDeviceVerified)
-                .toHaveBeenCalledWith(alice.getUserId(), alice.deviceId);
+            const bobDevice
+                  = await alice.getStoredDevice("@bob:example.com", "Dynabook");
+            expect(bobDevice.isVerified()).toBeTruthy();
+            const aliceDevice
+                  = await bob.getStoredDevice("@alice:example.com", "Osborne2");
+            expect(aliceDevice.isVerified()).toBeTruthy();
         });
 
         it("should be able to verify using the old MAC", async function() {
@@ -218,10 +218,40 @@ describe("SAS verification", function() {
 
             expect(macMethod).toBe("hmac-sha256");
 
-            expect(alice.setDeviceVerified)
-                .toHaveBeenCalledWith(bob.getUserId(), bob.deviceId);
-            expect(bob.setDeviceVerified)
-                .toHaveBeenCalledWith(alice.getUserId(), alice.deviceId);
+            const bobDevice
+                  = await alice.getStoredDevice("@bob:example.com", "Dynabook");
+            expect(bobDevice.isVerified()).toBeTruthy();
+            const aliceDevice
+                  = await bob.getStoredDevice("@alice:example.com", "Osborne2");
+            expect(aliceDevice.isVerified()).toBeTruthy();
+        });
+
+        it("should verify a cross-signing key", async function() {
+            const privateKeys = {};
+            alice.on("cross-signing:savePrivateKeys", function(e) {
+                privateKeys.alice = e;
+            });
+            await alice.resetCrossSigningKeys();
+            bob.on("cross-signing:savePrivateKeys", function(e) {
+                privateKeys.bob = e;
+            });
+            await bob.resetCrossSigningKeys();
+
+            bob.on("cross-signing:getKey", function(e) {
+                e.done(privateKeys.bob[e.type]);
+            });
+
+            bob._crypto._deviceList.storeCrossSigningForUser("@alice:example.com", {
+                keys: alice._crypto._crossSigningInfo.keys,
+            });
+            await Promise.all([
+                aliceVerifier.verify(),
+                bobPromise.then((verifier) => verifier.verify()),
+            ]);
+
+            expect(alice.checkDeviceTrust("@bob:example.com", "Dynabook")).toBe(1);
+            expect(bob.checkUserTrust("@alice:example.com")).toBe(6);
+            expect(bob.checkDeviceTrust("@alice:example.com", "Osborne2")).toBe(1);
         });
     });
 

src/client.js

@@ -854,6 +854,9 @@ MatrixClient.prototype.resetCrossSigningKeys
 MatrixClient.prototype.setCrossSigningKeys
     = wrapCryptoFunc("setCrossSigningKeys");
 
+MatrixClient.prototype.getCrossSigningId
+    = wrapCryptoFunc("getCrossSigningId");
+
 /**
  * Cancel a room key request for this event if one is ongoing and resend the
  * request.

src/crypto/index.js

@@ -286,6 +286,18 @@ Crypto.prototype.setCrossSigningKeys = function(keys) {
     this._baseApis.emit("cross-signing:keysChanged", {});
 };
 
+/**
+ * Get the user's cross-signing key ID.
+ *
+ * @param {string} type The type of key to get the ID of.  One of "master",
+ * "self_signing", or "user_signing".  Defaults to "master".
+ *
+ * @returns {string} the key ID
+ */
+Crypto.prototype.getCrossSigningId = function(type) {
+    return this._crossSigningInfo.getId(type);
+};
+
 /**
  * Check whether a given user is trusted.
  *

src/crypto/verification/Base.js

@@ -22,6 +22,7 @@ limitations under the License.
 import {MatrixEvent} from '../../models/event';
 import {EventEmitter} from 'events';
 import logger from '../../logger';
+import DeviceInfo from '../deviceinfo';
 
 export default class VerificationBase extends EventEmitter {
     /**
@@ -192,11 +193,24 @@ export default class VerificationBase extends EventEmitter {
         for (const [keyId, keyInfo] of Object.entries(keys)) {
             const deviceId = keyId.split(':', 2)[1];
             const device = await this._baseApis.getStoredDevice(userId, deviceId);
-            if (!device) {
-                logger.warn(`verification: Could not find device ${deviceId} to verify`);
-            } else {
+            if (device) {
                 await verifier(keyId, device, keyInfo);
                 verifiedDevices.push(deviceId);
+            } else {
+                const crossSigningInfo = this._baseApis._crypto._deviceList
+                      .getStoredCrossSigningForUser(userId);
+                if (crossSigningInfo && crossSigningInfo.getId() === deviceId) {
+                    await verifier(keyId, DeviceInfo.fromStorage({
+                        keys: {
+                            [keyId]: deviceId,
+                        },
+                    }, deviceId), keyInfo);
+                    verifiedDevices.push(deviceId);
+                } else {
+                    logger.warn(
+                        `verification: Could not find device ${deviceId} to verify`,
+                    );
+                }
             }
         }
 

src/crypto/verification/SAS.js

@@ -354,19 +354,32 @@ export default class SAS extends Base {
     }
 
     _sendMAC(olmSAS, method) {
-        const keyId = `ed25519:${this._baseApis.deviceId}`;
         const mac = {};
+        const keyList = [];
         const baseInfo = "MATRIX_KEY_VERIFICATION_MAC"
               + this._baseApis.getUserId() + this._baseApis.deviceId
               + this.userId + this.deviceId
               + this.transactionId;
 
-        mac[keyId] = olmSAS[macMethods[method]](
+        const deviceKeyId = `ed25519:${this._baseApis.deviceId}`;
+        mac[deviceKeyId] = olmSAS[macMethods[method]](
             this._baseApis.getDeviceEd25519Key(),
-            baseInfo + keyId,
+            baseInfo + deviceKeyId,
         );
+        keyList.push(deviceKeyId);
+
+        const crossSigningId = this._baseApis.getCrossSigningId();
+        if (crossSigningId) {
+            const crossSigningKeyId = `ed25519:${crossSigningId}`;
+            mac[crossSigningKeyId] = olmSAS[macMethods[method]](
+                crossSigningId,
+                baseInfo + crossSigningKeyId,
+            );
+            keyList.push(crossSigningKeyId);
+        }
+
         const keys = olmSAS[macMethods[method]](
-            keyId,
+            keyList.sort().join(","),
             baseInfo + "KEY_IDS",
         );
         this._sendToDevice("m.key.verification.mac", { mac, keys });