fix: Allow empty OMEMO messages to bypass trust

This commit is contained in:
PapaTutuWawa 2022-08-09 14:45:04 +02:00
parent fa16f97113
commit cb43bbb112
3 changed files with 50 additions and 2 deletions

View File

@ -224,8 +224,11 @@ class OmemoSessionManager {
// We assume that the user already checked if the session exists
for (final jid in jids) {
for (final deviceId in _deviceMap[jid]!) {
// Only encrypt to devices that are trusted
if (!(await _trustManager.isTrusted(jid, deviceId))) continue;
// Empty OMEMO messages are allowed to bypass trust
if (plaintext != null) {
// Only encrypt to devices that are trusted
if (!(await _trustManager.isTrusted(jid, deviceId))) continue;
}
final ratchetKey = RatchetMapKey(jid, deviceId);
final ratchet = _ratchetMap[ratchetKey]!;

14
lib/src/trust/never.dart Normal file
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@ -0,0 +1,14 @@
import 'package:meta/meta.dart';
import 'package:omemo_dart/src/trust/base.dart';
/// Only use for testing!
/// An implementation of TrustManager that never trusts any device and thus
/// has no internal state.
@visibleForTesting
class NeverTrustingTrustManager extends TrustManager {
@override
Future<bool> isTrusted(String jid, int deviceId) async => false;
@override
Future<void> onNewSession(String jid, int deviceId) async {}
}

View File

@ -1,5 +1,6 @@
import 'package:omemo_dart/omemo_dart.dart';
import 'package:omemo_dart/src/trust/always.dart';
import 'package:omemo_dart/src/trust/never.dart';
import 'package:test/test.dart';
void main() {
@ -336,4 +337,34 @@ void main() {
);
expect(messagePlaintext, bobMessage);
});
test('Test trust bypassing with empty OMEMO messages', () async {
const aliceJid = 'alice@server.example';
const bobJid = 'bob@other.server.example';
// Alice and Bob generate their sessions
final aliceSession = await OmemoSessionManager.generateNewIdentity(
aliceJid,
NeverTrustingTrustManager(),
opkAmount: 1,
);
final bobSession = await OmemoSessionManager.generateNewIdentity(
bobJid,
NeverTrustingTrustManager(),
opkAmount: 1,
);
// Alice encrypts an empty message for Bob
final aliceMessage = await aliceSession.encryptToJid(
bobJid,
null,
newSessions: [
await (await bobSession.getDevice()).toBundle(),
],
);
// Despite Alice not trusting Bob's device, we should have encrypted it for his
// untrusted device.
expect(aliceMessage.encryptedKeys.length, 1);
});
}