implement storing room keys

This commit is contained in:
Bruno Windels 2020-09-02 14:24:38 +02:00
parent f5c7b1b3ec
commit 6d3aa219fa
6 changed files with 132 additions and 8 deletions

View file

@ -20,10 +20,15 @@ import {OLM_ALGORITHM, MEGOLM_ALGORITHM} from "./e2ee/common.js";
const PENDING_ENCRYPTED_EVENTS = "pendingEncryptedDeviceEvents";
export class DeviceMessageHandler {
constructor({storage, olmDecryption, megolmEncryption}) {
constructor({storage}) {
this._storage = storage;
this._olmDecryption = null;
this._megolmDecryption = null;
}
enableEncryption({olmDecryption, megolmDecryption}) {
this._olmDecryption = olmDecryption;
this._megolmEncryption = megolmEncryption;
this._megolmDecryption = megolmDecryption;
}
async writeSync(toDeviceEvents, txn) {
@ -35,25 +40,28 @@ export class DeviceMessageHandler {
// we don't handle anything other for now
}
async _handleDecryptedEvents(payloads, txn) {
async _writeDecryptedEvents(payloads, txn) {
const megOlmRoomKeysPayloads = payloads.filter(p => {
return p.event.type === "m.room_key" && p.event.content?.algorithm === MEGOLM_ALGORITHM;
return p.event?.type === "m.room_key" && p.event.content?.algorithm === MEGOLM_ALGORITHM;
});
let megolmChanges;
if (megOlmRoomKeysPayloads.length) {
megolmChanges = await this._megolmEncryption.addRoomKeys(megOlmRoomKeysPayloads, txn);
megolmChanges = await this._megolmDecryption.addRoomKeys(megOlmRoomKeysPayloads, txn);
}
return {megolmChanges};
}
applyChanges({megolmChanges}) {
if (megolmChanges) {
this._megolmEncryption.applyRoomKeyChanges(megolmChanges);
this._megolmDecryption.applyRoomKeyChanges(megolmChanges);
}
}
// not safe to call multiple times without awaiting first call
async decryptPending() {
if (!this._olmDecryption) {
return;
}
const readTxn = await this._storage.readTxn([this._storage.storeNames.session]);
const pendingEvents = this._getPendingEvents(readTxn);
// only know olm for now
@ -66,11 +74,11 @@ export class DeviceMessageHandler {
// both to remove the pending events and to modify the olm account
this._storage.storeNames.session,
this._storage.storeNames.olmSessions,
// this._storage.storeNames.megolmInboundSessions,
this._storage.storeNames.inboundGroupSessions,
]);
let changes;
try {
changes = await this._handleDecryptedEvent(decryptChanges.payloads, txn);
changes = await this._writeDecryptedEvents(decryptChanges.payloads, txn);
decryptChanges.write(txn);
txn.session.remove(PENDING_ENCRYPTED_EVENTS);
} catch (err) {

View file

@ -0,0 +1,68 @@
/*
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.
*/
// senderKey is a curve25519 key
export class Decryption {
constructor({pickleKey}) {
this._pickleKey = pickleKey;
}
async addRoomKeys(payloads, txn) {
const newSessions = [];
for (const {senderKey, event} of payloads) {
const roomId = event.content?.["room_id"];
const sessionId = event.content?.["session_id"];
const sessionKey = event.content?.["session_key"];
if (
typeof roomId !== "string" ||
typeof sessionId !== "string" ||
typeof senderKey !== "string" ||
typeof sessionKey !== "string"
) {
return;
}
const hasSession = await txn.inboundGroupSessions.has(roomId, senderKey, sessionId);
if (!hasSession) {
const session = new this._olm.InboundGroupSession();
try {
session.create(sessionKey);
const sessionEntry = {
roomId,
senderKey,
sessionId,
session: session.pickle(this._pickleKey),
claimedKeys: event.keys,
};
txn.megOlmInboundSessions.set(sessionEntry);
newSessions.push(sessionEntry);
} finally {
session.free();
}
}
}
return newSessions;
}
applyRoomKeyChanges(newSessions) {
// retry decryption with the new sessions
if (newSessions.length) {
console.log(`I have ${newSessions.length} new inbound group sessions`, newSessions)
}
}
}

View file

@ -25,6 +25,7 @@ export const STORE_NAMES = Object.freeze([
"userIdentities",
"deviceIdentities",
"olmSessions",
"inboundGroupSessions",
]);
export const STORE_MAP = Object.freeze(STORE_NAMES.reduce((nameMap, name) => {

View file

@ -27,6 +27,7 @@ import {PendingEventStore} from "./stores/PendingEventStore.js";
import {UserIdentityStore} from "./stores/UserIdentityStore.js";
import {DeviceIdentityStore} from "./stores/DeviceIdentityStore.js";
import {OlmSessionStore} from "./stores/OlmSessionStore.js";
import {InboundGroupSessionStore} from "./stores/InboundGroupSessionStore.js";
export class Transaction {
constructor(txn, allowedStoreNames) {
@ -96,6 +97,10 @@ export class Transaction {
return this._store("olmSessions", idbStore => new OlmSessionStore(idbStore));
}
get inboundGroupSessions() {
return this._store("inboundGroupSessions", idbStore => new InboundGroupSessionStore(idbStore));
}
complete() {
return txnAsPromise(this._txn);
}

View file

@ -11,6 +11,7 @@ export const schema = [
migrateSession,
createIdentityStores,
createOlmSessionStore,
createInboundGroupSessionsStore,
];
// TODO: how to deal with git merge conflicts of this array?
@ -76,3 +77,8 @@ function createIdentityStores(db) {
function createOlmSessionStore(db) {
db.createObjectStore("olmSessions", {keyPath: "key"});
}
//v6
function createInboundGroupSessionsStore(db) {
db.createObjectStore("inboundGroupSessions", {keyPath: "key"});
}

View file

@ -0,0 +1,36 @@
/*
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.
*/
function encodeKey(roomId, senderKey, sessionId) {
return `${roomId}|${senderKey}|${sessionId}`;
}
export class InboundGroupSessionStore {
constructor(store) {
this._store = store;
}
async has(roomId, senderKey, sessionId) {
const key = encodeKey(roomId, senderKey, sessionId);
const fetchedKey = await this._store.getKey(key);
return key === fetchedKey;
}
set(session) {
session.key = encodeKey(session.roomId, session.senderKey, session.sessionId);
this._store.put(session);
}
}