create/load olm account before first sync

src/matrix/Session.js

@@ -18,6 +18,8 @@ import {Room} from "./room/Room.js";
 import { ObservableMap } from "../observable/index.js";
 import { SendScheduler, RateLimitingBackoff } from "./SendScheduler.js";
 import {User} from "./User.js";
+import {Account as E2EEAccount} from "./e2ee/Account.js";
+const PICKLE_KEY = "DEFAULT_KEY";
 
 export class Session {
     // sessionInfo contains deviceId, userId and homeServer
@@ -31,6 +33,34 @@ export class Session {
         this._roomUpdateCallback = (room, params) => this._rooms.update(room.id, params);
         this._user = new User(sessionInfo.userId);
         this._olm = olm;
+        this._e2eeAccount = null;
+    }
+
+    async beforeFirstSync(isNewLogin) {
+        if (this._olm) {
+            if (isNewLogin && this._e2eeAccount) {
+                throw new Error("there should not be an e2ee account already on a fresh login");
+            }
+            if (!this._e2eeAccount) {
+                const txn = await this._storage.readWriteTxn([
+                    this._storage.storeNames.session
+                ]);
+                try {
+                    this._e2eeAccount = await E2EEAccount.create({
+                        hsApi: this._hsApi,
+                        olm: this._olm,
+                        pickleKey: PICKLE_KEY,
+                        userId: this._sessionInfo.userId,
+                        deviceId: this._sessionInfo.deviceId,
+                        txn
+                    });
+                } catch (err) {
+                    txn.abort();
+                    throw err;
+                }
+                await txn.complete();
+            }
+        }
     }
 
     async load() {
@@ -44,6 +74,17 @@ export class Session {
         ]);
         // restore session object
         this._syncInfo = await txn.session.get("sync");
+        // restore e2ee account, if any
+        if (this._olm) {
+            this._e2eeAccount = await E2EEAccount.load({
+                hsApi: this._hsApi,
+                olm: this._olm,
+                pickleKey: PICKLE_KEY,
+                userId: this._sessionInfo.userId,
+                deviceId: this._sessionInfo.deviceId,
+                txn
+            });
+        }
         const pendingEventsByRoomId = await this._getPendingEventsByRoom(txn);
         // load rooms
         const rooms = await txn.roomSummary.getAll();

src/matrix/SessionContainer.js

@@ -74,7 +74,7 @@ export class SessionContainer {
             if (!sessionInfo) {
                 throw new Error("Invalid session id: " + sessionId);
             }
-            await this._loadSessionInfo(sessionInfo);
+            await this._loadSessionInfo(sessionInfo, false);
         } catch (err) {
             this._error = err;
             this._status.set(LoadStatus.Error);
@@ -121,14 +121,14 @@ export class SessionContainer {
         // LoadStatus.Error in case of an error,
         // so separate try/catch
         try {
-            await this._loadSessionInfo(sessionInfo);
+            await this._loadSessionInfo(sessionInfo, true);
         } catch (err) {
             this._error = err;
             this._status.set(LoadStatus.Error);
         }
     }
 
-    async _loadSessionInfo(sessionInfo) {
+    async _loadSessionInfo(sessionInfo, isNewLogin) {
         this._status.set(LoadStatus.Loading);
         this._reconnector = new Reconnector({
             onlineStatus: this._onlineStatus,
@@ -153,6 +153,7 @@ export class SessionContainer {
         const olm = await this._olmPromise;
         this._session = new Session({storage: this._storage, sessionInfo: filteredSessionInfo, hsApi, olm});
         await this._session.load();
+        await this._session.beforeFirstSync(isNewLogin);
         
         this._sync = new Sync({hsApi, storage: this._storage, session: this._session});
         // notify sync and session when back online

src/matrix/e2ee/Account.js

@@ -0,0 +1,54 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import anotherjson from "../../../lib/another-json/index.js";
+
+const ACCOUNT_SESSION_KEY = "olmAccount";
+const DEVICE_KEY_FLAG_SESSION_KEY = "areDeviceKeysUploaded";
+
+export class Account {
+    static async load({olm, pickleKey, hsApi, userId, deviceId, txn}) {
+        const pickledAccount = await txn.session.get(ACCOUNT_SESSION_KEY);
+        if (pickledAccount) {
+            const account = new olm.Account();
+            const areDeviceKeysUploaded = await txn.session.get(DEVICE_KEY_FLAG_SESSION_KEY);
+            account.unpickle(pickleKey, pickledAccount);
+            return new Account({pickleKey, hsApi, account, userId, deviceId, areDeviceKeysUploaded});
+        }
+    }
+
+    static async create({olm, pickleKey, hsApi, userId, deviceId, txn}) {
+        const account = new olm.Account();
+        account.create();
+        account.generate_one_time_keys(account.max_number_of_one_time_keys());
+        const pickledAccount = account.pickle(pickleKey);
+        // add will throw if the key already exists
+        // we would not want to overwrite olmAccount here
+        const areDeviceKeysUploaded = false;
+        await txn.session.add(ACCOUNT_SESSION_KEY, pickledAccount);
+        await txn.session.add(DEVICE_KEY_FLAG_SESSION_KEY, areDeviceKeysUploaded);
+        return new Account({pickleKey, hsApi, account, userId, deviceId, areDeviceKeysUploaded});
+    }
+
+    constructor({pickleKey, hsApi, account, userId, deviceId, areDeviceKeysUploaded}) {
+        this._pickleKey = pickleKey;
+        this._hsApi = hsApi;
+        this._account = account;
+        this._userId = userId;
+        this._deviceId = deviceId;
+        this._areDeviceKeysUploaded = areDeviceKeysUploaded;
+    }
+}

src/matrix/storage/idb/stores/SessionStore.js

@@ -45,4 +45,8 @@ export class SessionStore {
 	set(key, value) {
 		return this._sessionStore.put({key, value});
 	}
+
+    add(key, value) {
+        return this._sessionStore.put({key, value});
+    }
 }