release: Bump version

CHANGELOG.md

@@ -9,3 +9,14 @@
 
 - Fix bug with the Double Ratchet causing only the initial message to be decryptable
 - Expose `getDeviceMap` as a developer usable function
+
+## 0.2.0
+
+- Add convenience functions `getDeviceId` and `getDeviceBundle`
+- Creating a new ratchet with an id for which we already have a ratchet will now overwrite the old ratchet
+- Ratchet now carry an "acknowledged" attribute
+
+## 0.2.1
+
+- Add `isRatchetAcknowledged`
+- Ratchets that are created due to accepting a kex are now unacknowledged

README.md

@@ -28,7 +28,7 @@ Include `omemo_dart` in your `pubspec.yaml` like this:
 dependencies:
   omemo_dart:
     hosted: https://git.polynom.me/api/packages/PapaTutuWawa/pub
-    version: ^0.1.0
+    version: ^0.2.0
   # [...]
 
 # [...]

example/omemo_dart_example.dart

@@ -65,7 +65,7 @@ void main() async {
     // a new session. Let's also assume that Bob only has one device. We may, however,
     // add more bundles to newSessions, if we know of more.
     newSessions: [
-      await (await bobSession.getDevice()).toBundle(),
+      await bobSession.getDeviceBundle(),
     ],
   );
 

lib/src/double_ratchet/double_ratchet.dart

@@ -197,7 +197,7 @@ class OmemoDoubleRatchet {
       ik,
       ad,
       {},
-      true,
+      false,
     );
   }
 

lib/src/omemo/device.dart

@@ -163,6 +163,23 @@ class Device {
     );
   }
 
+  /// Returns a new device that is equal to this one with the exception that the new
+  /// device's id is a new number between 0 and 2**32 - 1.
+  @internal
+  Device withNewId() {
+    return Device(
+      jid,
+      generateRandom32BitNumber(),
+      ik,
+      spk,
+      spkId,
+      spkSignature,
+      oldSpk,
+      oldSpkId,
+      opks,
+    );
+  }
+  
   /// Converts this device into an OmemoBundle that could be used for publishing.
   Future<OmemoBundle> toBundle() async {
     final encodedOpks = <int, String>{};

lib/src/omemo/sessionmanager.dart

@@ -103,6 +103,18 @@ class OmemoSessionManager {
 
     return dev!;
   }
+
+  /// Returns the id attribute of our own device. This is just a short-hand for
+  /// ```await (session.getDevice()).id```.
+  Future<int> getDeviceId() async {
+    return _deviceLock.synchronized(() => _device.id);
+  }
+
+  /// Returns the device as an OmemoBundle. This is just a short-hand for
+  /// ```await (await session.getDevice()).toBundle()```.
+  Future<OmemoBundle> getDeviceBundle() async {
+    return _deviceLock.synchronized(() async => _device.toBundle());
+  }
   
   /// Add a session [ratchet] with the [deviceId] to the internal tracking state.
   Future<void> _addSession(String jid, int deviceId, OmemoDoubleRatchet ratchet) async {
@@ -110,21 +122,22 @@ class OmemoSessionManager {
       // Add the bundle Id
       if (!_deviceMap.containsKey(jid)) {
         _deviceMap[jid] = [deviceId];
-      } else {
-        _deviceMap[jid]!.add(deviceId);
-      }
 
-      // Commit the device map
+        // Commit the device map
-      _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+        _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+      } else {
+        // Prevent having the same device multiple times in the list
+        if (!_deviceMap[jid]!.contains(deviceId)) {
+          _deviceMap[jid]!.add(deviceId);
+
+          // Commit the device map
+          _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+        }
+      }
 
       // Add the ratchet session
       final key = RatchetMapKey(jid, deviceId);
-      if (!_ratchetMap.containsKey(key)) {
+      _ratchetMap[key] = ratchet;
-        _ratchetMap[key] = ratchet;
-      } else {
-        // TODO(PapaTutuWawa): What do we do now?
-        throw Exception();
-      }
 
       // Commit the ratchet
       _eventStreamController.add(RatchetModifiedEvent(jid, deviceId, ratchet));
@@ -433,20 +446,27 @@ class OmemoSessionManager {
 
   /// Returns the list of device identifiers belonging to [jid] that are yet unacked, i.e.
   /// we have not yet received an empty OMEMO message from.
-  Future<List<int>> getUnacknowledgedRatchets(String jid) async {
+  Future<List<int>?> getUnacknowledgedRatchets(String jid) async {
-    final ret = List<int>.empty(growable: true);
+    return _lock.synchronized(() async {
+      final ret = List<int>.empty(growable: true);
+      final devices = _deviceMap[jid];
+      if (devices == null) return null;
 
-    await _lock.synchronized(() async {
-      final devices = _deviceMap[jid]!;
       for (final device in devices) {
         final ratchet = _ratchetMap[RatchetMapKey(jid, device)]!;
         if (!ratchet.acknowledged) ret.add(device);
       }
-    });
 
-    return ret;
+      return ret;
+    });
   }
 
+  /// Returns true if the ratchet for [jid] with device identifier [deviceId] is
+  /// acknowledged. Returns false if not.
+  Future<bool> isRatchetAcknowledged(String jid, int deviceId) async {
+    return _lock.synchronized(() => _ratchetMap[RatchetMapKey(jid, deviceId)]!.acknowledged);
+  }
+  
   /// Mark the ratchet for device [deviceId] from [jid] as acked.
   Future<void> ratchetAcknowledged(String jid, int deviceId) async {
     await _lock.synchronized(() async {
@@ -457,6 +477,28 @@ class OmemoSessionManager {
       _eventStreamController.add(RatchetModifiedEvent(jid, deviceId, ratchet));
     });
   }
+
+  /// Generates an entirely new device. May be useful when the user wants to reset their cryptographic
+  /// identity. Triggers an event to commit it to storage.
+  Future<void> regenerateDevice({ int opkAmount = 100 }) async {
+    await _deviceLock.synchronized(() async {
+      _device = await Device.generateNewDevice(_device.jid, opkAmount: opkAmount);
+
+      // Commit it
+      _eventStreamController.add(DeviceModifiedEvent(_device));
+    });
+  }
+
+  /// Make our device have a new identifier. Only useful before publishing it as a bundle
+  /// to make sure that our device has a id that is account unique.
+  Future<void> regenerateDeviceId() async {
+    await _deviceLock.synchronized(() async {
+      _device = _device.withNewId();
+
+      // Commit it
+      _eventStreamController.add(DeviceModifiedEvent(_device));
+    });
+  }
   
   @visibleForTesting
   OmemoDoubleRatchet getRatchet(String jid, int deviceId) => _ratchetMap[RatchetMapKey(jid, deviceId)]!;

pubspec.yaml

@@ -1,6 +1,6 @@
 name: omemo_dart
 description: An XMPP library independent OMEMO library
-version: 0.1.3
+version: 0.2.1
 homepage: https://github.com/PapaTutuWawa/omemo_dart
 publish_to: https://git.polynom.me/api/packages/PapaTutuWawa/pub
 

test/omemo_test.dart

@@ -38,7 +38,7 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -50,7 +50,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -81,7 +81,7 @@ void main() {
     final aliceReceivedMessage = await aliceSession.decryptMessage(
       bobResponseMessage.ciphertext,
       bobJid,
-      (await bobSession.getDevice()).id,
+      await bobSession.getDeviceId(),
       bobResponseMessage.encryptedKeys,
     );
     expect(bobResponseText, aliceReceivedMessage);
@@ -115,8 +115,8 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
-        await (await bobSession2.getDevice()).toBundle(),
+        await bobSession2.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 2);
@@ -130,7 +130,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -149,7 +149,7 @@ void main() {
     final aliceReceivedMessage = await aliceSession.decryptMessage(
       bobResponseMessage.ciphertext,
       bobJid,
-      (await bobSession.getDevice()).id,
+      await bobSession.getDeviceId(),
       bobResponseMessage.encryptedKeys,
     );
     expect(bobResponseText, aliceReceivedMessage);
@@ -192,8 +192,8 @@ void main() {
       [bobJid, aliceJid],
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
-        await (await aliceSession2.getDevice()).toBundle(),
+        await aliceSession2.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 2);
@@ -205,7 +205,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession1.getDevice()).id,
+      await aliceSession1.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -214,7 +214,7 @@ void main() {
     final aliceMessage2 = await aliceSession2.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession1.getDevice()).id,
+      await aliceSession1.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, aliceMessage2);
@@ -241,7 +241,7 @@ void main() {
       bobJid,
       null,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -254,13 +254,13 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(bobMessage, null);
 
     // This call must not cause an exception
-    bobSession.getRatchet(aliceJid, (await aliceSession.getDevice()).id);
+    bobSession.getRatchet(aliceJid, await aliceSession.getDeviceId());
   });
 
   test('Test rotating the Signed Prekey', () async {
@@ -316,7 +316,7 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -331,7 +331,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -358,7 +358,7 @@ void main() {
       bobJid,
       null,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
 
@@ -387,7 +387,7 @@ void main() {
       bobJid,
       'Hello Bob!',
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
 
@@ -397,7 +397,7 @@ void main() {
     await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
 
@@ -416,7 +416,7 @@ void main() {
       final aliceReceivedMessage = await aliceSession.decryptMessage(
         bobResponseMessage.ciphertext,
         bobJid,
-        (await bobSession.getDevice()).id,
+        await bobSession.getDeviceId(),
         bobResponseMessage.encryptedKeys,
       );
       expect(messageText, aliceReceivedMessage);
@@ -448,14 +448,14 @@ void main() {
         bobJid,
         'Hallo Welt',
         newSessions: [
-          await (await bobSession1.getDevice()).toBundle(),
+          await bobSession1.getDeviceBundle(),
-          await (await bobSession2.getDevice()).toBundle(),
+          await bobSession2.getDeviceBundle(),
         ],
       );
 
       // One of those two sessions is broken, so Alice removes the session2 ratchet
-      final id1 = (await bobSession1.getDevice()).id;
+      final id1 = await bobSession1.getDeviceId();
-      final id2 = (await bobSession2.getDevice()).id;
+      final id2 = await bobSession2.getDeviceId();
       await aliceSession.removeRatchet(bobJid, id1);
 
       final map = aliceSession.getRatchetMap();
@@ -485,12 +485,12 @@ void main() {
         bobJid,
         'Hallo Welt',
         newSessions: [
-          await (await bobSession.getDevice()).toBundle(),
+          await bobSession.getDeviceBundle(),
         ],
       );
 
       // One of those two sessions is broken, so Alice removes the session2 ratchet
-      final id = (await bobSession.getDevice()).id;
+      final id = await bobSession.getDeviceId();
       await aliceSession.removeRatchet(bobJid, id);
 
       final map = aliceSession.getRatchetMap();
@@ -520,13 +520,13 @@ void main() {
       bobJid,
       'Hallo Welt',
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(
       await aliceSession.getUnacknowledgedRatchets(bobJid),
       [
-        (await bobSession.getDevice()).id,
+        await bobSession.getDeviceId(),
       ],
     );
 
@@ -537,10 +537,81 @@ void main() {
     // ...
 
     // Alice marks the ratchet as acknowledged
-    await aliceSession.ratchetAcknowledged(bobJid, (await bobSession.getDevice()).id);
+    await aliceSession.ratchetAcknowledged(bobJid, await bobSession.getDeviceId());
     expect(
-      (await aliceSession.getUnacknowledgedRatchets(bobJid)).isEmpty,
+      (await aliceSession.getUnacknowledgedRatchets(bobJid))!.isEmpty,
       true,
     );
   });
+
+  test('Test overwriting sessions', () async {
+    const aliceJid = 'alice@server.example';
+    const bobJid = 'bob@other.server.example';
+    // Alice and Bob generate their sessions
+    final aliceSession = await OmemoSessionManager.generateNewIdentity(
+      aliceJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+    final bobSession = await OmemoSessionManager.generateNewIdentity(
+      bobJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 2,
+    );
+
+    // Alice sends Bob a message
+    final msg1 = await aliceSession.encryptToJid(
+      bobJid,
+      'Hallo Welt',
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+    await bobSession.decryptMessage(
+      msg1.ciphertext,
+      aliceJid,
+      await aliceSession.getDeviceId(),
+      msg1.encryptedKeys,
+    );
+    final aliceRatchet1 = aliceSession.getRatchet(
+      bobJid,
+      await bobSession.getDeviceId(),
+    );
+    final bobRatchet1 = bobSession.getRatchet(
+      aliceJid,
+      await aliceSession.getDeviceId(),
+    );
+
+    // Alice is impatient and immediately sends another message before the original one
+    // can be acknowledged by Bob
+    final msg2 = await aliceSession.encryptToJid(
+      bobJid,
+      "Why don't you answer?",
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+    await bobSession.decryptMessage(
+      msg2.ciphertext,
+      aliceJid,
+      await aliceSession.getDeviceId(),
+      msg2.encryptedKeys,
+    );
+    final aliceRatchet2 = aliceSession.getRatchet(
+      bobJid,
+      await bobSession.getDeviceId(),
+    );
+    final bobRatchet2 = bobSession.getRatchet(
+      aliceJid,
+      await aliceSession.getDeviceId(),
+    );
+
+    // Both should only have one ratchet
+    expect(aliceSession.getRatchetMap().length, 1);
+    expect(bobSession.getRatchetMap().length, 1);
+    
+    // The ratchets should both be different
+    expect(await aliceRatchet1.equals(aliceRatchet2), false);
+    expect(await bobRatchet1.equals(bobRatchet2), false);
+  });
 }

test/serialisation_test.dart

@@ -49,16 +49,16 @@ void main() {
       bobJid,
       'Hello Bob!',
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
-    final aliceOld = aliceSession.getRatchet(bobJid, (await bobSession.getDevice()).id);
+    final aliceOld = aliceSession.getRatchet(bobJid, await bobSession.getDeviceId());
     final aliceSerialised = await aliceOld.toJson();
     final aliceNew = OmemoDoubleRatchet.fromJson(aliceSerialised);
 
@@ -79,8 +79,8 @@ void main() {
     );
     await oldSession.addSessionFromBundle(
       'bob@localhost',
-      (await bobSession.getDevice()).id,
+      await bobSession.getDeviceId(),
-      await (await bobSession.getDevice()).toBundle(),
+      await bobSession.getDeviceBundle(),
     );
 
     // Serialise and deserialise