276 lines
12 KiB
JavaScript
276 lines
12 KiB
JavaScript
/*
|
|
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";
|
|
import {SESSION_KEY_PREFIX, OLM_ALGORITHM, MEGOLM_ALGORITHM} from "./common.js";
|
|
|
|
// use common prefix so it's easy to clear properties that are not e2ee related during session clear
|
|
const ACCOUNT_SESSION_KEY = SESSION_KEY_PREFIX + "olmAccount";
|
|
const DEVICE_KEY_FLAG_SESSION_KEY = SESSION_KEY_PREFIX + "areDeviceKeysUploaded";
|
|
const SERVER_OTK_COUNT_SESSION_KEY = SESSION_KEY_PREFIX + "serverOTKCount";
|
|
|
|
export class Account {
|
|
static async load({olm, pickleKey, hsApi, userId, deviceId, olmWorker, 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);
|
|
const serverOTKCount = await txn.session.get(SERVER_OTK_COUNT_SESSION_KEY);
|
|
return new Account({pickleKey, hsApi, account, userId,
|
|
deviceId, areDeviceKeysUploaded, serverOTKCount, olm, olmWorker});
|
|
}
|
|
}
|
|
|
|
static async create({olm, pickleKey, hsApi, userId, deviceId, olmWorker, storage}) {
|
|
const account = new olm.Account();
|
|
if (olmWorker) {
|
|
await olmWorker.createAccountAndOTKs(account, account.max_number_of_one_time_keys());
|
|
} else {
|
|
account.create();
|
|
account.generate_one_time_keys(account.max_number_of_one_time_keys());
|
|
}
|
|
const pickledAccount = account.pickle(pickleKey);
|
|
const areDeviceKeysUploaded = false;
|
|
const txn = await storage.readWriteTxn([
|
|
storage.storeNames.session
|
|
]);
|
|
try {
|
|
// add will throw if the key already exists
|
|
// we would not want to overwrite olmAccount here
|
|
txn.session.add(ACCOUNT_SESSION_KEY, pickledAccount);
|
|
txn.session.add(DEVICE_KEY_FLAG_SESSION_KEY, areDeviceKeysUploaded);
|
|
txn.session.add(SERVER_OTK_COUNT_SESSION_KEY, 0);
|
|
} catch (err) {
|
|
txn.abort();
|
|
throw err;
|
|
}
|
|
await txn.complete();
|
|
return new Account({pickleKey, hsApi, account, userId,
|
|
deviceId, areDeviceKeysUploaded, serverOTKCount: 0, olm, olmWorker});
|
|
}
|
|
|
|
constructor({pickleKey, hsApi, account, userId, deviceId, areDeviceKeysUploaded, serverOTKCount, olm, olmWorker}) {
|
|
this._olm = olm;
|
|
this._pickleKey = pickleKey;
|
|
this._hsApi = hsApi;
|
|
this._account = account;
|
|
this._userId = userId;
|
|
this._deviceId = deviceId;
|
|
this._areDeviceKeysUploaded = areDeviceKeysUploaded;
|
|
this._serverOTKCount = serverOTKCount;
|
|
this._olmWorker = olmWorker;
|
|
this._identityKeys = JSON.parse(this._account.identity_keys());
|
|
}
|
|
|
|
get identityKeys() {
|
|
return this._identityKeys;
|
|
}
|
|
|
|
async uploadKeys(storage, log) {
|
|
const oneTimeKeys = JSON.parse(this._account.one_time_keys());
|
|
// only one algorithm supported by olm atm, so hardcode its name
|
|
const oneTimeKeysEntries = Object.entries(oneTimeKeys.curve25519);
|
|
if (oneTimeKeysEntries.length || !this._areDeviceKeysUploaded) {
|
|
const payload = {};
|
|
if (!this._areDeviceKeysUploaded) {
|
|
log.set("identity", true);
|
|
const identityKeys = JSON.parse(this._account.identity_keys());
|
|
payload.device_keys = this._deviceKeysPayload(identityKeys);
|
|
}
|
|
if (oneTimeKeysEntries.length) {
|
|
log.set("otks", true);
|
|
payload.one_time_keys = this._oneTimeKeysPayload(oneTimeKeysEntries);
|
|
}
|
|
const response = await this._hsApi.uploadKeys(payload, {log}).response();
|
|
this._serverOTKCount = response?.one_time_key_counts?.signed_curve25519;
|
|
log.set("serverOTKCount", this._serverOTKCount);
|
|
// TODO: should we not modify this in the txn like we do elsewhere?
|
|
// we'd have to pickle and unpickle the account to clone it though ...
|
|
// and the upload has succeed at this point, so in-memory would be correct
|
|
// but in-storage not if the txn fails.
|
|
await this._updateSessionStorage(storage, sessionStore => {
|
|
if (oneTimeKeysEntries.length) {
|
|
this._account.mark_keys_as_published();
|
|
sessionStore.set(ACCOUNT_SESSION_KEY, this._account.pickle(this._pickleKey));
|
|
sessionStore.set(SERVER_OTK_COUNT_SESSION_KEY, this._serverOTKCount);
|
|
}
|
|
if (!this._areDeviceKeysUploaded) {
|
|
this._areDeviceKeysUploaded = true;
|
|
sessionStore.set(DEVICE_KEY_FLAG_SESSION_KEY, this._areDeviceKeysUploaded);
|
|
}
|
|
});
|
|
}
|
|
}
|
|
|
|
async generateOTKsIfNeeded(storage, log) {
|
|
// We need to keep a pool of one time public keys on the server so that
|
|
// other devices can start conversations with us. But we can only store
|
|
// a finite number of private keys in the olm Account object.
|
|
// To complicate things further then can be a delay between a device
|
|
// claiming a public one time key from the server and it sending us a
|
|
// message. We need to keep the corresponding private key locally until
|
|
// we receive the message.
|
|
// But that message might never arrive leaving us stuck with duff
|
|
// private keys clogging up our local storage.
|
|
// So we need some kind of engineering compromise to balance all of
|
|
// these factors.
|
|
|
|
// Check how many keys we can store in the Account object.
|
|
const maxOTKs = this._account.max_number_of_one_time_keys();
|
|
// Try to keep at most half that number on the server. This leaves the
|
|
// rest of the slots free to hold keys that have been claimed from the
|
|
// server but we haven't recevied a message for.
|
|
// If we run out of slots when generating new keys then olm will
|
|
// discard the oldest private keys first. This will eventually clean
|
|
// out stale private keys that won't receive a message.
|
|
const keyLimit = Math.floor(maxOTKs / 2);
|
|
// does the server have insufficient OTKs?
|
|
if (this._serverOTKCount < keyLimit) {
|
|
const oneTimeKeys = JSON.parse(this._account.one_time_keys());
|
|
const oneTimeKeysEntries = Object.entries(oneTimeKeys.curve25519);
|
|
const unpublishedOTKCount = oneTimeKeysEntries.length;
|
|
// we want to end up with maxOTKs / 2 key on the server,
|
|
// so generate any on top of the remaining ones on the server and the unpublished ones
|
|
// (we have generated before but haven't uploaded yet for some reason)
|
|
// to get to that number.
|
|
const newKeyCount = keyLimit - unpublishedOTKCount - this._serverOTKCount;
|
|
if (newKeyCount > 0) {
|
|
await log.wrap("generate otks", log => {
|
|
log.set("max", maxOTKs);
|
|
log.set("server", this._serverOTKCount);
|
|
log.set("unpublished", unpublishedOTKCount);
|
|
log.set("new", newKeyCount);
|
|
log.set("limit", keyLimit);
|
|
this._account.generate_one_time_keys(newKeyCount);
|
|
this._updateSessionStorage(storage, sessionStore => {
|
|
sessionStore.set(ACCOUNT_SESSION_KEY, this._account.pickle(this._pickleKey));
|
|
});
|
|
});
|
|
}
|
|
// even though we didn't generate any keys, we still have some unpublished ones that should be published
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
createInboundOlmSession(senderKey, body) {
|
|
const newSession = new this._olm.Session();
|
|
try {
|
|
newSession.create_inbound_from(this._account, senderKey, body);
|
|
return newSession;
|
|
} catch (err) {
|
|
newSession.free();
|
|
throw err;
|
|
}
|
|
}
|
|
|
|
async createOutboundOlmSession(theirIdentityKey, theirOneTimeKey) {
|
|
const newSession = new this._olm.Session();
|
|
try {
|
|
if (this._olmWorker) {
|
|
await this._olmWorker.createOutboundOlmSession(this._account, newSession, theirIdentityKey, theirOneTimeKey);
|
|
} else {
|
|
newSession.create_outbound(this._account, theirIdentityKey, theirOneTimeKey);
|
|
}
|
|
return newSession;
|
|
} catch (err) {
|
|
newSession.free();
|
|
throw err;
|
|
}
|
|
}
|
|
|
|
writeRemoveOneTimeKey(session, txn) {
|
|
// this is side-effecty and will have applied the change if the txn fails,
|
|
// but don't want to clone the account for now
|
|
// and it is not the worst thing to think we have used a OTK when
|
|
// decrypting the message that actually used it threw for some reason.
|
|
this._account.remove_one_time_keys(session);
|
|
txn.session.set(ACCOUNT_SESSION_KEY, this._account.pickle(this._pickleKey));
|
|
}
|
|
|
|
writeSync(deviceOneTimeKeysCount, txn, log) {
|
|
// we only upload signed_curve25519 otks
|
|
const otkCount = deviceOneTimeKeysCount.signed_curve25519 || 0;
|
|
if (Number.isSafeInteger(otkCount) && otkCount !== this._serverOTKCount) {
|
|
txn.session.set(SERVER_OTK_COUNT_SESSION_KEY, otkCount);
|
|
log.set("otkCount", otkCount);
|
|
return otkCount;
|
|
}
|
|
}
|
|
|
|
afterSync(otkCount) {
|
|
// could also be undefined
|
|
if (Number.isSafeInteger(otkCount)) {
|
|
this._serverOTKCount = otkCount;
|
|
}
|
|
}
|
|
|
|
_deviceKeysPayload(identityKeys) {
|
|
const obj = {
|
|
user_id: this._userId,
|
|
device_id: this._deviceId,
|
|
algorithms: [OLM_ALGORITHM, MEGOLM_ALGORITHM],
|
|
keys: {}
|
|
};
|
|
for (const [algorithm, pubKey] of Object.entries(identityKeys)) {
|
|
obj.keys[`${algorithm}:${this._deviceId}`] = pubKey;
|
|
}
|
|
this.signObject(obj);
|
|
return obj;
|
|
}
|
|
|
|
_oneTimeKeysPayload(oneTimeKeysEntries) {
|
|
const obj = {};
|
|
for (const [keyId, pubKey] of oneTimeKeysEntries) {
|
|
const keyObj = {
|
|
key: pubKey
|
|
};
|
|
this.signObject(keyObj);
|
|
obj[`signed_curve25519:${keyId}`] = keyObj;
|
|
}
|
|
return obj;
|
|
}
|
|
|
|
async _updateSessionStorage(storage, callback) {
|
|
const txn = await storage.readWriteTxn([
|
|
storage.storeNames.session
|
|
]);
|
|
try {
|
|
await callback(txn.session);
|
|
} catch (err) {
|
|
txn.abort();
|
|
throw err;
|
|
}
|
|
await txn.complete();
|
|
}
|
|
|
|
signObject(obj) {
|
|
const sigs = obj.signatures || {};
|
|
const unsigned = obj.unsigned;
|
|
|
|
delete obj.signatures;
|
|
delete obj.unsigned;
|
|
|
|
sigs[this._userId] = sigs[this._userId] || {};
|
|
sigs[this._userId]["ed25519:" + this._deviceId] =
|
|
this._account.sign(anotherjson.stringify(obj));
|
|
obj.signatures = sigs;
|
|
if (unsigned !== undefined) {
|
|
obj.unsigned = unsigned;
|
|
}
|
|
}
|
|
}
|