/*
* Famedly Matrix SDK
* Copyright (C) 2019, 2020 Famedly GmbH
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*/
import 'dart:convert';
import 'package:pedantic/pedantic.dart';
import 'package:famedlysdk/famedlysdk.dart';
import 'package:famedlysdk/matrix_api.dart';
import 'package:olm/olm.dart' as olm;
import './encryption.dart';
import './utils/session_key.dart';
import './utils/outbound_group_session.dart';
const MEGOLM_KEY = 'm.megolm_backup.v1';
class KeyManager {
final Encryption encryption;
Client get client => encryption.client;
final outgoingShareRequests = {};
final incomingShareRequests = {};
final _inboundGroupSessions = >{};
final _outboundGroupSessions = {};
final Set _loadedOutboundGroupSessions = {};
final Set _requestedSessionIds = {};
KeyManager(this.encryption) {
encryption.ssss.setValidator(MEGOLM_KEY, (String secret) async {
final keyObj = olm.PkDecryption();
try {
final info = await getRoomKeysInfo();
return keyObj.init_with_private_key(base64.decode(secret)) ==
info['auth_data']['public_key'];
} catch (_) {
return false;
} finally {
keyObj.free();
}
});
}
bool get enabled => client.accountData[MEGOLM_KEY] != null;
/// clear all cached inbound group sessions. useful for testing
void clearInboundGroupSessions() {
_inboundGroupSessions.clear();
}
void setInboundGroupSession(String roomId, String sessionId, String senderKey,
Map content,
{bool forwarded = false}) {
final oldSession =
getInboundGroupSession(roomId, sessionId, senderKey, otherRooms: false);
if (oldSession != null) {
return;
}
if (content['algorithm'] != 'm.megolm.v1.aes-sha2') {
return;
}
olm.InboundGroupSession inboundGroupSession;
try {
inboundGroupSession = olm.InboundGroupSession();
if (forwarded) {
inboundGroupSession.import_session(content['session_key']);
} else {
inboundGroupSession.create(content['session_key']);
}
} catch (e) {
inboundGroupSession.free();
print(
'[LibOlm] Could not create new InboundGroupSession: ' + e.toString());
return;
}
if (!_inboundGroupSessions.containsKey(roomId)) {
_inboundGroupSessions[roomId] = {};
}
_inboundGroupSessions[roomId][sessionId] = SessionKey(
content: content,
inboundGroupSession: inboundGroupSession,
indexes: {},
key: client.userID,
);
client.database?.storeInboundGroupSession(
client.id,
roomId,
sessionId,
inboundGroupSession.pickle(client.userID),
json.encode(content),
json.encode({}),
);
// TODO: somehow try to decrypt last message again
final room = client.getRoomById(roomId);
if (room != null) {
room.onSessionKeyReceived.add(sessionId);
}
}
SessionKey getInboundGroupSession(
String roomId, String sessionId, String senderKey,
{bool otherRooms = true}) {
if (_inboundGroupSessions.containsKey(roomId) &&
_inboundGroupSessions[roomId].containsKey(sessionId)) {
return _inboundGroupSessions[roomId][sessionId];
}
if (!otherRooms) {
return null;
}
// search if this session id is *somehow* found in another room
for (final val in _inboundGroupSessions.values) {
if (val.containsKey(sessionId)) {
return val[sessionId];
}
}
return null;
}
/// Loads an inbound group session
Future loadInboundGroupSession(
String roomId, String sessionId, String senderKey) async {
if (roomId == null || sessionId == null || senderKey == null) {
return null;
}
if (_inboundGroupSessions.containsKey(roomId) &&
_inboundGroupSessions[roomId].containsKey(sessionId)) {
return _inboundGroupSessions[roomId][sessionId]; // nothing to do
}
final session = await client.database
?.getDbInboundGroupSession(client.id, roomId, sessionId);
if (session == null) {
final room = client.getRoomById(roomId);
final requestIdent = '$roomId|$sessionId|$senderKey';
if (client.enableE2eeRecovery &&
room != null &&
!_requestedSessionIds.contains(requestIdent)) {
// do e2ee recovery
_requestedSessionIds.add(requestIdent);
unawaited(request(room, sessionId, senderKey));
}
return null;
}
if (!_inboundGroupSessions.containsKey(roomId)) {
_inboundGroupSessions[roomId] = {};
}
final sess = SessionKey.fromDb(session, client.userID);
if (!sess.isValid) {
return null;
}
_inboundGroupSessions[roomId][sessionId] = sess;
return sess;
}
/// clear all cached inbound group sessions. useful for testing
void clearOutboundGroupSessions() {
_outboundGroupSessions.clear();
}
/// Clears the existing outboundGroupSession but first checks if the participating
/// devices have been changed. Returns false if the session has not been cleared because
/// it wasn't necessary.
Future clearOutboundGroupSession(String roomId,
{bool wipe = false}) async {
final room = client.getRoomById(roomId);
final sess = getOutboundGroupSession(roomId);
if (room == null || sess == null) {
return true;
}
if (!wipe) {
// first check if the devices in the room changed
final deviceKeys = await room.getUserDeviceKeys();
deviceKeys.removeWhere((k) => k.blocked);
final deviceKeyIds = deviceKeys.map((k) => k.deviceId).toList();
deviceKeyIds.sort();
if (deviceKeyIds.toString() != sess.devices.toString()) {
wipe = true;
}
// next check if it needs to be rotated
final encryptionContent = room.getState(EventTypes.Encryption)?.content;
final maxMessages = encryptionContent != null &&
encryptionContent['rotation_period_msgs'] is int
? encryptionContent['rotation_period_msgs']
: 100;
final maxAge = encryptionContent != null &&
encryptionContent['rotation_period_ms'] is int
? encryptionContent['rotation_period_ms']
: 604800000; // default of one week
if (sess.sentMessages >= maxMessages ||
sess.creationTime
.add(Duration(milliseconds: maxAge))
.isBefore(DateTime.now())) {
wipe = true;
}
if (!wipe) {
return false;
}
}
sess.dispose();
_outboundGroupSessions.remove(roomId);
await client.database?.removeOutboundGroupSession(client.id, roomId);
return true;
}
Future storeOutboundGroupSession(
String roomId, OutboundGroupSession sess) async {
if (sess == null) {
return;
}
await client.database?.storeOutboundGroupSession(
client.id,
roomId,
sess.outboundGroupSession.pickle(client.userID),
json.encode(sess.devices),
sess.creationTime,
sess.sentMessages);
}
Future createOutboundGroupSession(String roomId) async {
await clearOutboundGroupSession(roomId, wipe: true);
final room = client.getRoomById(roomId);
if (room == null) {
return null;
}
final deviceKeys = await room.getUserDeviceKeys();
deviceKeys.removeWhere((k) => k.blocked);
final deviceKeyIds = deviceKeys.map((k) => k.deviceId).toList();
deviceKeyIds.sort();
final outboundGroupSession = olm.OutboundGroupSession();
try {
outboundGroupSession.create();
} catch (e) {
outboundGroupSession.free();
print('[LibOlm] Unable to create new outboundGroupSession: ' +
e.toString());
return null;
}
final rawSession = {
'algorithm': 'm.megolm.v1.aes-sha2',
'room_id': room.id,
'session_id': outboundGroupSession.session_id(),
'session_key': outboundGroupSession.session_key(),
};
setInboundGroupSession(
roomId, rawSession['session_id'], encryption.identityKey, rawSession);
final sess = OutboundGroupSession(
devices: deviceKeyIds,
creationTime: DateTime.now(),
outboundGroupSession: outboundGroupSession,
sentMessages: 0,
key: client.userID,
);
try {
await client.sendToDevice(deviceKeys, 'm.room_key', rawSession);
await storeOutboundGroupSession(roomId, sess);
_outboundGroupSessions[roomId] = sess;
} catch (e, s) {
print(
'[LibOlm] Unable to send the session key to the participating devices: ' +
e.toString());
print(s);
sess.dispose();
return null;
}
return sess;
}
OutboundGroupSession getOutboundGroupSession(String roomId) {
return _outboundGroupSessions[roomId];
}
Future loadOutboundGroupSession(String roomId) async {
if (_loadedOutboundGroupSessions.contains(roomId) ||
_outboundGroupSessions.containsKey(roomId) ||
client.database == null) {
return; // nothing to do
}
_loadedOutboundGroupSessions.add(roomId);
final session =
await client.database.getDbOutboundGroupSession(client.id, roomId);
if (session == null) {
return;
}
final sess = OutboundGroupSession.fromDb(session, client.userID);
if (!sess.isValid) {
return;
}
_outboundGroupSessions[roomId] = sess;
}
Future