moxxy/lib/service/omemo/omemo.dart

426 lines
14 KiB
Dart

import 'dart:async';
import 'dart:collection';
import 'package:flutter/foundation.dart';
import 'package:get_it/get_it.dart';
import 'package:hex/hex.dart';
import 'package:logging/logging.dart';
import 'package:moxxmpp/moxxmpp.dart' as moxxmpp;
import 'package:moxxyv2/service/database/database.dart';
import 'package:moxxyv2/service/message.dart';
import 'package:moxxyv2/service/moxxmpp/omemo.dart';
import 'package:moxxyv2/service/omemo/implementations.dart';
import 'package:moxxyv2/service/omemo/types.dart';
import 'package:moxxyv2/service/service.dart';
import 'package:moxxyv2/service/xmpp.dart';
import 'package:moxxyv2/shared/events.dart';
import 'package:moxxyv2/shared/models/message.dart';
import 'package:moxxyv2/shared/models/omemo_device.dart' as model;
import 'package:omemo_dart/omemo_dart.dart';
import 'package:synchronized/synchronized.dart';
class OmemoDoubleRatchetWrapper {
OmemoDoubleRatchetWrapper(this.ratchet, this.id, this.jid);
final OmemoDoubleRatchet ratchet;
final int id;
final String jid;
}
class OmemoService {
final Logger _log = Logger('OmemoService');
bool _initialized = false;
final Lock _lock = Lock();
final Queue<Completer<void>> _waitingForInitialization = Queue<Completer<void>>();
final Map<String, Map<int, String>> _fingerprintCache = {};
late OmemoManager omemoManager;
Future<void> initializeIfNeeded(String jid) async {
final done = await _lock.synchronized(() => _initialized);
if (done) return;
final db = GetIt.I.get<DatabaseService>();
var device = await db.loadOmemoDevice(jid);
if (device == null) {
_log.info('No OMEMO marker found. Generating OMEMO identity...');
// Generate the identity in the background
device = await compute(generateNewIdentityImpl, jid);
await commitDevice(device!);
await commitDeviceMap(<String, List<int>>{});
await commitTrustManager(await omemoManager.trustManager.toJson());
} else {
_log.info('OMEMO marker found. Restoring OMEMO state...');
final ratchetMap = <RatchetMapKey, OmemoDoubleRatchet>{};
for (final ratchet in await GetIt.I.get<DatabaseService>().loadRatchets()) {
final key = RatchetMapKey(ratchet.jid, ratchet.id);
ratchetMap[key] = ratchet.ratchet;
}
final db = GetIt.I.get<DatabaseService>();
final om = GetIt.I.get<moxxmpp.XmppConnection>().
getManagerById<moxxmpp.BaseOmemoManager>(moxxmpp.omemoManager)!;
omemoManager = OmemoManager(
device,
await loadTrustManager(),
om.sendEmptyMessageImpl,
om.fetchDeviceList,
om.fetchDeviceBundle,
om.subscribeToDeviceListImpl,
);
omemoManager.initialize(
ratchetMap,
await db.loadOmemoDeviceList(),
);
}
omemoManager.eventStream.listen((event) async {
if (event is RatchetModifiedEvent) {
await GetIt.I.get<DatabaseService>().saveRatchet(
OmemoDoubleRatchetWrapper(event.ratchet, event.deviceId, event.jid),
);
if (event.added) {
// Cache the fingerprint
final fingerprint = await event.ratchet.getOmemoFingerprint();
await GetIt.I.get<DatabaseService>().addFingerprintsToCache([
OmemoCacheTriple(
event.jid,
event.deviceId,
fingerprint,
),
]);
if (_fingerprintCache.containsKey(event.jid)) {
_fingerprintCache[event.jid]![event.deviceId] = fingerprint;
}
await addNewDeviceMessage(event.jid, event.deviceId);
}
} else if (event is DeviceListModifiedEvent) {
await commitDeviceMap(event.list);
} else if (event is DeviceModifiedEvent) {
await commitDevice(event.device);
// Publish it
await GetIt.I.get<moxxmpp.XmppConnection>()
.getManagerById<moxxmpp.BaseOmemoManager>(moxxmpp.omemoManager)!
.publishBundle(await event.device.toBundle());
}
});
await _lock.synchronized(() {
_initialized = true;
for (final c in _waitingForInitialization) {
c.complete();
}
_waitingForInitialization.clear();
});
}
/// Adds a pseudo message saying that [jid] added a new device with id [deviceId].
/// If, however, [jid] is our own JID, then nothing is done.
Future<void> addNewDeviceMessage(String jid, int deviceId) async {
// Add a pseudo message if it is not about our own devices
final xmppState = await GetIt.I.get<XmppService>().getXmppState();
if (jid == xmppState.jid) return;
final ms = GetIt.I.get<MessageService>();
final message = await ms.addMessageFromData(
'',
DateTime.now().millisecondsSinceEpoch,
'',
jid,
false,
'',
false,
false,
false,
pseudoMessageType: pseudoMessageTypeNewDevice,
pseudoMessageData: <String, dynamic>{
'deviceId': deviceId,
'jid': jid,
},
);
sendEvent(
MessageAddedEvent(
message: message,
),
);
}
Future<model.OmemoDevice> regenerateDevice(String jid) async {
// Prevent access to the session manager as it is (mostly) guarded ensureInitialized
await _lock.synchronized(() {
_initialized = false;
});
_log.info('No OMEMO marker found. Generating OMEMO identity...');
final oldId = await omemoManager.getDeviceId();
// Clear the database
await GetIt.I.get<DatabaseService>().emptyOmemoSessionTables();
// Regenerate the identity in the background
final device = await compute(generateNewIdentityImpl, jid);
await omemoManager.replaceDevice(device);
await commitDevice(device);
await commitDeviceMap(<String, List<int>>{});
await commitTrustManager(await omemoManager.trustManager.toJson());
// Remove the old device
final omemo = GetIt.I.get<moxxmpp.XmppConnection>()
.getManagerById<moxxmpp.BaseOmemoManager>(moxxmpp.omemoManager)!;
await omemo.deleteDevice(oldId);
// Publish the new one
await omemo.publishBundle(await omemoManager.getDeviceBundle());
// Allow access again
await _lock.synchronized(() {
_initialized = true;
for (final c in _waitingForInitialization) {
c.complete();
}
_waitingForInitialization.clear();
});
// Return the OmemoDevice
return model.OmemoDevice(
await getDeviceFingerprint(),
true,
true,
true,
await getDeviceId(),
);
}
/// Ensures that the code following this *AWAITED* call can access every method
/// of the OmemoService.
Future<void> ensureInitialized() async {
final completer = await _lock.synchronized(() {
if (!_initialized) {
final c = Completer<void>();
_waitingForInitialization.add(c);
return c;
}
return null;
});
if (completer != null) {
await completer.future;
}
}
Future<void> commitDeviceMap(Map<String, List<int>> deviceMap) async {
await GetIt.I.get<DatabaseService>().saveOmemoDeviceList(deviceMap);
}
Future<void> commitDevice(OmemoDevice device) async {
await GetIt.I.get<DatabaseService>().saveOmemoDevice(device);
}
/// Requests our device list and checks if the current device is in it. If not, then
/// it will be published.
Future<Object?> publishDeviceIfNeeded() async {
_log.finest('publishDeviceIfNeeded: Waiting for initialization...');
await ensureInitialized();
_log.finest('publishDeviceIfNeeded: Done');
final conn = GetIt.I.get<moxxmpp.XmppConnection>();
final omemo = conn.getManagerById<moxxmpp.BaseOmemoManager>(moxxmpp.omemoManager)!;
final dm = conn.getManagerById<moxxmpp.DiscoManager>(moxxmpp.discoManager)!;
final bareJid = conn.getConnectionSettings().jid.toBare();
final device = await omemoManager.getDevice();
final bundlesRaw = await dm.discoItemsQuery(
bareJid.toString(),
node: moxxmpp.omemoBundlesXmlns,
);
if (bundlesRaw.isType<moxxmpp.DiscoError>()) {
await omemo.publishBundle(await device.toBundle());
return bundlesRaw.get<moxxmpp.DiscoError>();
}
final bundleIds = bundlesRaw
.get<List<moxxmpp.DiscoItem>>()
.where((item) => item.name != null)
.map((item) => int.parse(item.name!));
if (!bundleIds.contains(device.id)) {
final result = await omemo.publishBundle(await device.toBundle());
if (result.isType<moxxmpp.OmemoError>()) return result.get<moxxmpp.OmemoError>();
return null;
}
final idsRaw = await omemo.getDeviceList(bareJid);
final ids = idsRaw.isType<moxxmpp.OmemoError>() ? <int>[] : idsRaw.get<List<int>>();
if (!ids.contains(device.id)) {
final result = await omemo.publishBundle(await device.toBundle());
if (result.isType<moxxmpp.OmemoError>()) return result.get<moxxmpp.OmemoError>();
return null;
}
return null;
}
Future<void> _fetchFingerprintsAndCache(moxxmpp.JID jid) async {
final bareJid = jid.toBare().toString();
final allDevicesRaw = await GetIt.I.get<moxxmpp.XmppConnection>()
.getManagerById<moxxmpp.BaseOmemoManager>(moxxmpp.omemoManager)!
.retrieveDeviceBundles(jid);
if (allDevicesRaw.isType<List<OmemoBundle>>()) {
final allDevices = allDevicesRaw.get<List<OmemoBundle>>();
final map = <int, String>{};
final items = List<OmemoCacheTriple>.empty(growable: true);
for (final device in allDevices) {
final curveIk = await device.ik.toCurve25519();
final fingerprint = HEX.encode(await curveIk.getBytes());
map[device.id] = fingerprint;
items.add(OmemoCacheTriple(bareJid, device.id, fingerprint));
}
// Cache them in memory
_fingerprintCache[bareJid] = map;
// Cache them in the database
await GetIt.I.get<DatabaseService>().addFingerprintsToCache(items);
}
}
Future<void> _loadOrFetchFingerprints(moxxmpp.JID jid) async {
final bareJid = jid.toBare().toString();
if (!_fingerprintCache.containsKey(bareJid)) {
// First try to load it from the database
final triples = await GetIt.I.get<DatabaseService>()
.getFingerprintsFromCache(bareJid);
if (triples.isEmpty) {
// We found no fingerprints in the database, so try to fetch them
await _fetchFingerprintsAndCache(jid);
} else {
// We have fetched fingerprints from the database
_fingerprintCache[bareJid] = Map<int, String>.fromEntries(
triples.map((triple) {
return MapEntry<int, String>(
triple.deviceId,
triple.fingerprint,
);
}),
);
}
}
}
Future<List<model.OmemoDevice>> getOmemoKeysForJid(String jid) async {
await ensureInitialized();
// Get finger prints if we have to
await _loadOrFetchFingerprints(moxxmpp.JID.fromString(jid));
final keys = List<model.OmemoDevice>.empty(growable: true);
final tm = omemoManager.trustManager as BlindTrustBeforeVerificationTrustManager;
final trustMap = await tm.getDevicesTrust(jid);
if (!_fingerprintCache.containsKey(jid)) return [];
for (final deviceId in _fingerprintCache[jid]!.keys) {
keys.add(
model.OmemoDevice(
_fingerprintCache[jid]![deviceId]!,
await tm.isTrusted(jid, deviceId),
trustMap[deviceId] == BTBVTrustState.verified,
await tm.isEnabled(jid, deviceId),
deviceId,
),
);
}
return keys;
}
Future<void> commitTrustManager(Map<String, dynamic> json) async {
await GetIt.I.get<DatabaseService>().saveTrustCache(
json['trust']! as Map<String, int>,
);
await GetIt.I.get<DatabaseService>().saveTrustEnablementList(
json['enable']! as Map<String, bool>,
);
await GetIt.I.get<DatabaseService>().saveTrustDeviceList(
json['devices']! as Map<String, List<int>>,
);
}
Future<MoxxyBTBVTrustManager> loadTrustManager() async {
final db = GetIt.I.get<DatabaseService>();
return MoxxyBTBVTrustManager(
await db.loadTrustCache(),
await db.loadTrustEnablementList(),
await db.loadTrustDeviceList(),
);
}
Future<void> setOmemoKeyEnabled(String jid, int deviceId, bool enabled) async {
await ensureInitialized();
await omemoManager.trustManager.setEnabled(jid, deviceId, enabled);
}
Future<void> removeAllSessions(String jid) async {
await ensureInitialized();
// TODO(PapaTutuWawa): Reset trust decisions in the TrustManager
await omemoManager.removeAllRatchets(jid);
}
Future<int> getDeviceId() async {
await ensureInitialized();
return omemoManager.getDeviceId();
}
Future<String> getDeviceFingerprint() => omemoManager.getDeviceFingerprint();
/// Returns a list of OmemoDevices for devices we have sessions with and other devices
/// published on [ownJid]'s devices PubSub node.
/// Note that the list is made so that the current device is excluded.
Future<List<model.OmemoDevice>> getOwnFingerprints(moxxmpp.JID ownJid) async {
final ownId = await getDeviceId();
final keys = List<model.OmemoDevice>.from(
await getOmemoKeysForJid(ownJid.toString()),
);
final bareJid = ownJid.toBare().toString();
// Get fingerprints if we have to
await _loadOrFetchFingerprints(ownJid);
final tm = omemoManager.trustManager as BlindTrustBeforeVerificationTrustManager;
final trustMap = await tm.getDevicesTrust(bareJid);
for (final deviceId in _fingerprintCache[bareJid]!.keys) {
if (deviceId == ownId) continue;
final fingerprint = _fingerprintCache[bareJid]![deviceId]!;
keys.add(
model.OmemoDevice(
fingerprint,
await tm.isTrusted(bareJid, deviceId),
trustMap[deviceId] == BTBVTrustState.verified,
await tm.isEnabled(bareJid, deviceId),
deviceId,
hasSessionWith: false,
),
);
}
return keys;
}
Future<void> verifyDevice(int deviceId, String jid) async {
final tm = omemoManager.trustManager as BlindTrustBeforeVerificationTrustManager;
await tm.setDeviceTrust(
jid,
deviceId,
BTBVTrustState.verified,
);
}
}