feat: Add getDeviceId and getDeviceBundle

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/omemo/sessionmanager.dart

@@ -104,27 +104,40 @@ 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 {
     await _lock.synchronized(() async {
       // Add the bundle Id
       if (!_deviceMap.containsKey(jid)) {
         _deviceMap[jid] = [deviceId];
-      } else {
-        _deviceMap[jid]!.add(deviceId);
-      }
 
         // Commit the device map
         _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;
-      } else {
-        // TODO(PapaTutuWawa): What do we do now?
-        throw Exception();
-      }
 
       // Commit the ratchet
       _eventStreamController.add(RatchetModifiedEvent(jid, deviceId, ratchet));

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 (await bobSession2.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
+        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 (await aliceSession2.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
+        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 (await bobSession2.getDevice()).toBundle(),
+          await bobSession1.getDeviceBundle(),
+          await bobSession2.getDeviceBundle(),
         ],
       );
 
       // One of those two sessions is broken, so Alice removes the session2 ratchet
-      final id1 = (await bobSession1.getDevice()).id;
-      final id2 = (await bobSession2.getDevice()).id;
+      final id1 = await bobSession1.getDeviceId();
+      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,
       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 (await bobSession.getDevice()).toBundle(),
+      await bobSession.getDeviceId(),
+      await bobSession.getDeviceBundle(),
     );
 
     // Serialise and deserialise