Fix race in device list updates

spec/unit/crypto/DeviceList.spec.js

@@ -0,0 +1,128 @@
+import DeviceList from '../../../lib/crypto/DeviceList';
+import MockStorageApi from '../../MockStorageApi';
+import WebStorageSessionStore from '../../../lib/store/session/webstorage';
+import testUtils from '../../test-utils';
+import utils from '../../../lib/utils';
+
+import expect from 'expect';
+import q from 'q';
+
+const signedDeviceList = {
+    "failures": {},
+    "device_keys": {
+        "@test1:sw1v.org": {
+            "HGKAWHRVJQ": {
+                "signatures": {
+                    "@test1:sw1v.org": {
+                        "ed25519:HGKAWHRVJQ":
+                            "8PB450fxKDn5s8IiRZ2N2t6MiueQYVRLHFEzqIi1eLdxx1w" +
+                            "XEPC1/1Uz9T4gwnKlMVAKkhB5hXQA/3kjaeLABw",
+                    },
+                },
+                "user_id": "@test1:sw1v.org",
+                "keys": {
+                    "ed25519:HGKAWHRVJQ":
+                        "0gI/T6C+mn1pjtvnnW2yB2l1IIBb/5ULlBXi/LXFSEQ",
+                    "curve25519:HGKAWHRVJQ":
+                        "mbIZED1dBsgIgkgzxDpxKkJmsr4hiWlGzQTvUnQe3RY",
+                },
+                "algorithms": [
+                    "m.olm.v1.curve25519-aes-sha2",
+                    "m.megolm.v1.aes-sha2",
+                ],
+                "device_id": "HGKAWHRVJQ",
+                "unsigned": {},
+            },
+        },
+    },
+};
+
+describe('DeviceList', function() {
+    let downloadSpy;
+    let sessionStore;
+
+    beforeEach(function() {
+        testUtils.beforeEach(this); // eslint-disable-line no-invalid-this
+
+        downloadSpy = expect.createSpy();
+        const mockStorage = new MockStorageApi();
+        sessionStore = new WebStorageSessionStore(mockStorage);
+    });
+
+    function createTestDeviceList() {
+        const baseApis = {
+            downloadKeysForUsers: downloadSpy,
+        };
+        const mockOlm = {
+            verifySignature: function(key, message, signature) {},
+        };
+        return new DeviceList(baseApis, sessionStore, mockOlm);
+    }
+
+    it("should successfully download and store device keys", function() {
+        const dl = createTestDeviceList();
+
+        dl.startTrackingDeviceList('@test1:sw1v.org');
+
+        const queryDefer1 = q.defer();
+        downloadSpy.andReturn(queryDefer1.promise);
+
+        const prom1 = dl.refreshOutdatedDeviceLists();
+        expect(downloadSpy).toHaveBeenCalledWith(['@test1:sw1v.org'], {});
+        queryDefer1.resolve(utils.deepCopy(signedDeviceList));
+
+        return prom1.then(() => {
+            const storedKeys = sessionStore.getEndToEndDevicesForUser('@test1:sw1v.org');
+            expect(Object.keys(storedKeys)).toEqual(['HGKAWHRVJQ']);
+        });
+    });
+
+    it("should have an outdated devicelist on an invalidation while an " +
+       "update is in progress", function() {
+        const dl = createTestDeviceList();
+
+        dl.startTrackingDeviceList('@test1:sw1v.org');
+
+        const queryDefer1 = q.defer();
+        downloadSpy.andReturn(queryDefer1.promise);
+
+        const prom1 = dl.refreshOutdatedDeviceLists();
+        expect(downloadSpy).toHaveBeenCalledWith(['@test1:sw1v.org'], {});
+        downloadSpy.reset();
+
+        // outdated notif arrives while the request is in flight.
+        const queryDefer2 = q.defer();
+        downloadSpy.andReturn(queryDefer2.promise);
+
+        dl.invalidateUserDeviceList('@test1:sw1v.org');
+        dl.refreshOutdatedDeviceLists();
+
+        // the first request completes
+        queryDefer1.resolve({
+            device_keys: {
+                '@test1:sw1v.org': {},
+            },
+        });
+
+        return prom1.then(() => {
+            // uh-oh; user restarts before second request completes. The new instance
+            // should know we never got a complete device list.
+            console.log("Creating new devicelist to simulate app reload");
+            downloadSpy.reset();
+            const dl2 = createTestDeviceList();
+            const queryDefer3 = q.defer();
+            downloadSpy.andReturn(queryDefer3.promise);
+
+            const prom3 = dl2.refreshOutdatedDeviceLists();
+            expect(downloadSpy).toHaveBeenCalledWith(['@test1:sw1v.org'], {});
+
+            queryDefer3.resolve(utils.deepCopy(signedDeviceList));
+
+            // allow promise chain to complete
+            return prom3;
+        }).then(() => {
+            const storedKeys = sessionStore.getEndToEndDevicesForUser('@test1:sw1v.org');
+            expect(Object.keys(storedKeys)).toEqual(['HGKAWHRVJQ']);
+        });
+    });
+});

src/crypto/DeviceList.js

@@ -263,6 +263,9 @@ export default class DeviceList {
 
     /**
      * If we have users who have outdated device lists, start key downloads for them
+     *
+     * @returns {Promise} which completes when the download completes; normally there
+     *    is no need to wait for this (it's mostly for the unit tests).
      */
     refreshOutdatedDeviceLists() {
         const usersToDownload = [];
@@ -280,7 +283,7 @@ export default class DeviceList {
         // invalidateUserDeviceList, so do it now.
         this._persistDeviceTrackingStatus();
 
-        this._doKeyDownload(usersToDownload);
+        return this._doKeyDownload(usersToDownload);
     }
 
 
@@ -323,6 +326,14 @@ export default class DeviceList {
 
         const finished = (success) => {
             users.forEach((u) => {
+                // we may have queued up another download request for this user
+                // since we started this request. If that happens, we should
+                // ignore the completion of the first one.
+                if (this._keyDownloadsInProgressByUser[u] !== prom) {
+                    console.log('Another update in the queue for', u,
+                                '- not marking up-to-date');
+                    return;
+                }
                 delete this._keyDownloadsInProgressByUser[u];
                 const stat = this._deviceTrackingStatus[u];
                 if (stat == TRACKING_STATUS_DOWNLOAD_IN_PROGRESS) {