feat: Replay last sent olm message on olm session recovery from other device

lib/encryption/encryption.dart

@@ -93,6 +93,11 @@ class Encryption {
       // them in the background
       unawaited(runInRoot(() => keyManager.handleToDeviceEvent(event)));
     }
+    if (event.type == EventTypes.Dummy) {
+      // the previous device just had to create a new olm session, due to olm session
+      // corruption. We want to try to send it the last message we just sent it, if possible
+      unawaited(runInRoot(() => olmManager.handleToDeviceEvent(event)));
+    }
     if (event.type.startsWith('m.key.verification.')) {
       // some key verification event. No need to handle it now, we can easily
       // do this in the background
@@ -336,12 +341,6 @@ class Encryption {
     return encryptedPayload;
   }
 
-  Future<Map<String, dynamic>> encryptToDeviceMessagePayload(
-      DeviceKeys device, String type, Map<String, dynamic> payload) async {
-    return await olmManager.encryptToDeviceMessagePayload(
-        device, type, payload);
-  }
-
   Future<Map<String, dynamic>> encryptToDeviceMessage(
       List<DeviceKeys> deviceKeys,
       String type,

lib/encryption/olm_manager.dart

@@ -444,7 +444,7 @@ class OlmManager {
     }
     _restoredOlmSessionsTime[mapKey] = DateTime.now();
     await startOutgoingOlmSessions([device]);
-    await client.sendToDeviceEncrypted([device], 'm.dummy', {});
+    await client.sendToDeviceEncrypted([device], EventTypes.Dummy, {});
   }
 
   Future<ToDeviceEvent> decryptToDeviceEvent(ToDeviceEvent event) async {
@@ -542,6 +542,16 @@ class OlmManager {
     };
     final encryptResult = sess.first.session.encrypt(json.encode(fullPayload));
     storeOlmSession(sess.first);
+    if (client.database != null) {
+      unawaited(client.database.setLastSentMessageUserDeviceKey(
+          json.encode({
+            'type': type,
+            'content': payload,
+          }),
+          client.id,
+          device.userId,
+          device.deviceId));
+    }
     final encryptedBody = <String, dynamic>{
       'algorithm': AlgorithmTypes.olmV1Curve25519AesSha2,
       'sender_key': identityKey,
@@ -587,6 +597,35 @@ class OlmManager {
     return data;
   }
 
+  Future<void> handleToDeviceEvent(ToDeviceEvent event) async {
+    if (event.type == EventTypes.Dummy) {
+      // We receive dan encrypted m.dummy. This means that the other end was not able to
+      // decrypt our last message. So, we re-send it.
+      if (event.encryptedContent == null || client.database == null) {
+        return;
+      }
+      final device = client.getUserDeviceKeysByCurve25519Key(
+          event.encryptedContent.tryGet<String>('sender_key', ''));
+      if (device == null) {
+        return; // device not found
+      }
+      Logs().v(
+          '[OlmManager] Device ${device.userId}:${device.deviceId} generated a new olm session, replaying last sent message...');
+      final lastSentMessageRes = await client.database
+          .getLastSentMessageUserDeviceKey(
+              client.id, device.userId, device.deviceId)
+          .get();
+      if (lastSentMessageRes.isEmpty ||
+          (lastSentMessageRes.first?.isEmpty ?? true)) {
+        return;
+      }
+      final lastSentMessage = json.decode(lastSentMessageRes.first);
+      // okay, time to send the message!
+      await client.sendToDeviceEncrypted(
+          [device], lastSentMessage['type'], lastSentMessage['content']);
+    }
+  }
+
   void dispose() {
     for (final sessions in olmSessions.values) {
       for (final sess in sessions) {

lib/src/database/database.dart

@@ -70,7 +70,7 @@ class Database extends _$Database {
   Database.connect(DatabaseConnection connection) : super.connect(connection);
 
   @override
-  int get schemaVersion => 9;
+  int get schemaVersion => 10;
 
   int get maxFileSize => 1 * 1024 * 1024;
 
@@ -164,6 +164,12 @@ class Database extends _$Database {
                   userDeviceKeysKey, userDeviceKeysKey.lastActive);
               from++;
             }
+            if (from == 9) {
+              await m.addColumnIfNotExists(
+                  userDeviceKeysKey, userDeviceKeysKey.lastSentMessage);
+              await m.createIndexIfNotExists(olmSessionsIdentityIndex);
+              from++;
+            }
           } catch (e, s) {
             api.Logs().e('Database migration failed', e, s);
             onError.add(SdkError(exception: e, stackTrace: s));

lib/src/database/database.g.dart

@@ -769,6 +769,7 @@ class DbUserDeviceKeysKey extends DataClass
   final bool verified;
   final bool blocked;
   final int lastActive;
+  final String lastSentMessage;
   DbUserDeviceKeysKey(
       {@required this.clientId,
       @required this.userId,
@@ -776,7 +777,8 @@ class DbUserDeviceKeysKey extends DataClass
       @required this.content,
       this.verified,
       this.blocked,
-      this.lastActive});
+      this.lastActive,
+      this.lastSentMessage});
   factory DbUserDeviceKeysKey.fromData(
       Map<String, dynamic> data, GeneratedDatabase db,
       {String prefix}) {
@@ -799,6 +801,8 @@ class DbUserDeviceKeysKey extends DataClass
           boolType.mapFromDatabaseResponse(data['${effectivePrefix}blocked']),
       lastActive: intType
           .mapFromDatabaseResponse(data['${effectivePrefix}last_active']),
+      lastSentMessage: stringType
+          .mapFromDatabaseResponse(data['${effectivePrefix}last_sent_message']),
     );
   }
   @override
@@ -825,6 +829,9 @@ class DbUserDeviceKeysKey extends DataClass
     if (!nullToAbsent || lastActive != null) {
       map['last_active'] = Variable<int>(lastActive);
     }
+    if (!nullToAbsent || lastSentMessage != null) {
+      map['last_sent_message'] = Variable<String>(lastSentMessage);
+    }
     return map;
   }
 
@@ -850,6 +857,9 @@ class DbUserDeviceKeysKey extends DataClass
       lastActive: lastActive == null && nullToAbsent
           ? const Value.absent()
           : Value(lastActive),
+      lastSentMessage: lastSentMessage == null && nullToAbsent
+          ? const Value.absent()
+          : Value(lastSentMessage),
     );
   }
 
@@ -864,6 +874,7 @@ class DbUserDeviceKeysKey extends DataClass
       verified: serializer.fromJson<bool>(json['verified']),
       blocked: serializer.fromJson<bool>(json['blocked']),
       lastActive: serializer.fromJson<int>(json['last_active']),
+      lastSentMessage: serializer.fromJson<String>(json['last_sent_message']),
     );
   }
   @override
@@ -877,6 +888,7 @@ class DbUserDeviceKeysKey extends DataClass
       'verified': serializer.toJson<bool>(verified),
       'blocked': serializer.toJson<bool>(blocked),
       'last_active': serializer.toJson<int>(lastActive),
+      'last_sent_message': serializer.toJson<String>(lastSentMessage),
     };
   }
 
@@ -887,7 +899,8 @@ class DbUserDeviceKeysKey extends DataClass
           String content,
           bool verified,
           bool blocked,
-          int lastActive}) =>
+          int lastActive,
+          String lastSentMessage}) =>
       DbUserDeviceKeysKey(
         clientId: clientId ?? this.clientId,
         userId: userId ?? this.userId,
@@ -896,6 +909,7 @@ class DbUserDeviceKeysKey extends DataClass
         verified: verified ?? this.verified,
         blocked: blocked ?? this.blocked,
         lastActive: lastActive ?? this.lastActive,
+        lastSentMessage: lastSentMessage ?? this.lastSentMessage,
       );
   @override
   String toString() {
@@ -906,7 +920,8 @@ class DbUserDeviceKeysKey extends DataClass
           ..write('content: $content, ')
           ..write('verified: $verified, ')
           ..write('blocked: $blocked, ')
-          ..write('lastActive: $lastActive')
+          ..write('lastActive: $lastActive, ')
+          ..write('lastSentMessage: $lastSentMessage')
           ..write(')'))
         .toString();
   }
@@ -920,8 +935,12 @@ class DbUserDeviceKeysKey extends DataClass
               deviceId.hashCode,
               $mrjc(
                   content.hashCode,
-                  $mrjc(verified.hashCode,
+                  $mrjc(
-                      $mrjc(blocked.hashCode, lastActive.hashCode)))))));
+                      verified.hashCode,
+                      $mrjc(
+                          blocked.hashCode,
+                          $mrjc(lastActive.hashCode,
+                              lastSentMessage.hashCode))))))));
   @override
   bool operator ==(dynamic other) =>
       identical(this, other) ||
@@ -932,7 +951,8 @@ class DbUserDeviceKeysKey extends DataClass
           other.content == this.content &&
           other.verified == this.verified &&
           other.blocked == this.blocked &&
-          other.lastActive == this.lastActive);
+          other.lastActive == this.lastActive &&
+          other.lastSentMessage == this.lastSentMessage);
 }
 
 class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
@@ -943,6 +963,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
   final Value<bool> verified;
   final Value<bool> blocked;
   final Value<int> lastActive;
+  final Value<String> lastSentMessage;
   const UserDeviceKeysKeyCompanion({
     this.clientId = const Value.absent(),
     this.userId = const Value.absent(),
@@ -951,6 +972,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
     this.verified = const Value.absent(),
     this.blocked = const Value.absent(),
     this.lastActive = const Value.absent(),
+    this.lastSentMessage = const Value.absent(),
   });
   UserDeviceKeysKeyCompanion.insert({
     @required int clientId,
@@ -960,6 +982,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
     this.verified = const Value.absent(),
     this.blocked = const Value.absent(),
     this.lastActive = const Value.absent(),
+    this.lastSentMessage = const Value.absent(),
   })  : clientId = Value(clientId),
         userId = Value(userId),
         deviceId = Value(deviceId),
@@ -972,6 +995,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
     Expression<bool> verified,
     Expression<bool> blocked,
     Expression<int> lastActive,
+    Expression<String> lastSentMessage,
   }) {
     return RawValuesInsertable({
       if (clientId != null) 'client_id': clientId,
@@ -981,6 +1005,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
       if (verified != null) 'verified': verified,
       if (blocked != null) 'blocked': blocked,
       if (lastActive != null) 'last_active': lastActive,
+      if (lastSentMessage != null) 'last_sent_message': lastSentMessage,
     });
   }
 
@@ -991,7 +1016,8 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
       Value<String> content,
       Value<bool> verified,
       Value<bool> blocked,
-      Value<int> lastActive}) {
+      Value<int> lastActive,
+      Value<String> lastSentMessage}) {
     return UserDeviceKeysKeyCompanion(
       clientId: clientId ?? this.clientId,
       userId: userId ?? this.userId,
@@ -1000,6 +1026,7 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
       verified: verified ?? this.verified,
       blocked: blocked ?? this.blocked,
       lastActive: lastActive ?? this.lastActive,
+      lastSentMessage: lastSentMessage ?? this.lastSentMessage,
     );
   }
 
@@ -1027,6 +1054,9 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
     if (lastActive.present) {
       map['last_active'] = Variable<int>(lastActive.value);
     }
+    if (lastSentMessage.present) {
+      map['last_sent_message'] = Variable<String>(lastSentMessage.value);
+    }
     return map;
   }
 
@@ -1039,7 +1069,8 @@ class UserDeviceKeysKeyCompanion extends UpdateCompanion<DbUserDeviceKeysKey> {
           ..write('content: $content, ')
           ..write('verified: $verified, ')
           ..write('blocked: $blocked, ')
-          ..write('lastActive: $lastActive')
+          ..write('lastActive: $lastActive, ')
+          ..write('lastSentMessage: $lastSentMessage')
           ..write(')'))
         .toString();
   }
@@ -1108,9 +1139,27 @@ class UserDeviceKeysKey extends Table
         $customConstraints: '');
   }
 
+  final VerificationMeta _lastSentMessageMeta =
+      const VerificationMeta('lastSentMessage');
+  GeneratedTextColumn _lastSentMessage;
+  GeneratedTextColumn get lastSentMessage =>
+      _lastSentMessage ??= _constructLastSentMessage();
+  GeneratedTextColumn _constructLastSentMessage() {
+    return GeneratedTextColumn('last_sent_message', $tableName, true,
+        $customConstraints: '');
+  }
+
   @override
-  List<GeneratedColumn> get $columns =>
+  List<GeneratedColumn> get $columns => [
-      [clientId, userId, deviceId, content, verified, blocked, lastActive];
+        clientId,
+        userId,
+        deviceId,
+        content,
+        verified,
+        blocked,
+        lastActive,
+        lastSentMessage
+      ];
   @override
   UserDeviceKeysKey get asDslTable => this;
   @override
@@ -1161,6 +1210,12 @@ class UserDeviceKeysKey extends Table
           lastActive.isAcceptableOrUnknown(
               data['last_active'], _lastActiveMeta));
     }
+    if (data.containsKey('last_sent_message')) {
+      context.handle(
+          _lastSentMessageMeta,
+          lastSentMessage.isAcceptableOrUnknown(
+              data['last_sent_message'], _lastSentMessageMeta));
+    }
     return context;
   }
 
@@ -6136,6 +6191,10 @@ abstract class _$Database extends GeneratedDatabase {
   Index get olmSessionsIndex => _olmSessionsIndex ??= Index(
       'olm_sessions_index',
       'CREATE INDEX olm_sessions_index ON olm_sessions(client_id);');
+  Index _olmSessionsIdentityIndex;
+  Index get olmSessionsIdentityIndex => _olmSessionsIdentityIndex ??= Index(
+      'olm_sessions_identity_index',
+      'CREATE INDEX olm_sessions_identity_index ON olm_sessions(client_id, identity_key);');
   OutboundGroupSessions _outboundGroupSessions;
   OutboundGroupSessions get outboundGroupSessions =>
       _outboundGroupSessions ??= OutboundGroupSessions(this);
@@ -6574,6 +6633,35 @@ abstract class _$Database extends GeneratedDatabase {
     );
   }
 
+  Future<int> setLastSentMessageUserDeviceKey(String last_sent_message,
+      int client_id, String user_id, String device_id) {
+    return customUpdate(
+      'UPDATE user_device_keys_key SET last_sent_message = :last_sent_message WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id',
+      variables: [
+        Variable.withString(last_sent_message),
+        Variable.withInt(client_id),
+        Variable.withString(user_id),
+        Variable.withString(device_id)
+      ],
+      updates: {userDeviceKeysKey},
+      updateKind: UpdateKind.update,
+    );
+  }
+
+  Selectable<String> getLastSentMessageUserDeviceKey(
+      int client_id, String user_id, String device_id) {
+    return customSelect(
+        'SELECT last_sent_message FROM user_device_keys_key WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id',
+        variables: [
+          Variable.withInt(client_id),
+          Variable.withString(user_id),
+          Variable.withString(device_id)
+        ],
+        readsFrom: {
+          userDeviceKeysKey
+        }).map((QueryRow row) => row.readString('last_sent_message'));
+  }
+
   Future<int> setVerifiedUserCrossSigningKey(
       bool verified, int client_id, String user_id, String public_key) {
     return customUpdate(
@@ -7068,6 +7156,7 @@ abstract class _$Database extends GeneratedDatabase {
         userCrossSigningKeysIndex,
         olmSessions,
         olmSessionsIndex,
+        olmSessionsIdentityIndex,
         outboundGroupSessions,
         outboundGroupSessionsIndex,
         inboundGroupSessions,

lib/src/database/database.moor

@@ -29,6 +29,7 @@ CREATE TABLE user_device_keys_key (
   verified BOOLEAN DEFAULT false,
   blocked BOOLEAN DEFAULT false,
   last_active BIGINT,
+  last_sent_message TEXT,
   UNIQUE(client_id, user_id, device_id)
 ) as DbUserDeviceKeysKey;
 CREATE INDEX user_device_keys_key_index ON user_device_keys_key(client_id);
@@ -53,6 +54,7 @@ CREATE TABLE olm_sessions (
   UNIQUE(client_id, identity_key, session_id)
 ) AS DbOlmSessions;
 CREATE INDEX olm_sessions_index ON olm_sessions(client_id);
+CREATE INDEX olm_sessions_identity_index ON olm_sessions(client_id, identity_key);
 
 CREATE TABLE outbound_group_sessions (
   client_id INTEGER NOT NULL REFERENCES clients(client_id),
@@ -204,6 +206,8 @@ setBlockedUserDeviceKey: UPDATE user_device_keys_key SET blocked = :blocked WHER
 storeUserDeviceKey: INSERT OR REPLACE INTO user_device_keys_key (client_id, user_id, device_id, content, verified, blocked, last_active) VALUES (:client_id, :user_id, :device_id, :content, :verified, :blocked, :last_active);
 removeUserDeviceKey: DELETE FROM user_device_keys_key WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id;
 setLastActiveUserDeviceKey: UPDATE user_device_keys_key SET last_active = :last_active WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id;
+setLastSentMessageUserDeviceKey: UPDATE user_device_keys_key SET last_sent_message = :last_sent_message WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id;
+getLastSentMessageUserDeviceKey: SELECT last_sent_message FROM user_device_keys_key WHERE client_id = :client_id AND user_id = :user_id AND device_id = :device_id;
 setVerifiedUserCrossSigningKey: UPDATE user_cross_signing_keys SET verified = :verified WHERE client_id = :client_id AND user_id = :user_id AND public_key = :public_key;
 setBlockedUserCrossSigningKey: UPDATE user_cross_signing_keys SET blocked = :blocked WHERE client_id = :client_id AND user_id = :user_id AND public_key = :public_key;
 storeUserCrossSigningKey: INSERT OR REPLACE INTO user_cross_signing_keys (client_id, user_id, public_key, content, verified, blocked) VALUES (:client_id, :user_id, :public_key, :content, :verified, :blocked);

test/canonical_json_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/client_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/device_keys_list_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/bootstrap_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/cross_signing_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/encrypt_decrypt_room_message_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/encrypt_decrypt_to_device_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify
@@ -82,12 +82,6 @@ void main() {
           .encryptToDeviceMessage([device], 'm.to_device', {'hello': 'foxies'});
     });
 
-    test('encryptToDeviceMessagePayload', () async {
-      // just a hard test if nothing errors
-      await otherClient.encryption.encryptToDeviceMessagePayload(
-          device, 'm.to_device', {'hello': 'foxies'});
-    });
-
     test('decryptToDeviceEvent', () async {
       final encryptedEvent = ToDeviceEvent(
         sender: '@othertest:fakeServer.notExisting',

test/encryption/key_manager_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/key_request_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/key_verification_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/olm_manager_test.dart

@@ -1,6 +1,6 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
- *   Copyright (C) 2020 Famedly GmbH
+ *   Copyright (C) 2020, 2021 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
@@ -126,6 +126,88 @@ void main() {
           true);
     });
 
+    test('replay to_device events', () async {
+      final userId = '@alice:example.com';
+      final deviceId = 'JLAFKJWSCS';
+      final senderKey = 'L+4+JCl8MD63dgo8z5Ta+9QAHXiANyOVSfgbHA5d3H8';
+      FakeMatrixApi.calledEndpoints.clear();
+      await client.database.setLastSentMessageUserDeviceKey(
+          json.encode({
+            'type': 'm.foxies',
+            'content': {
+              'floof': 'foxhole',
+            },
+          }),
+          client.id,
+          userId,
+          deviceId);
+      var event = ToDeviceEvent(
+        sender: userId,
+        type: 'm.dummy',
+        content: {},
+        encryptedContent: {
+          'sender_key': senderKey,
+        },
+      );
+      await client.encryption.olmManager.handleToDeviceEvent(event);
+      expect(
+          FakeMatrixApi.calledEndpoints.keys.any(
+              (k) => k.startsWith('/client/r0/sendToDevice/m.room.encrypted')),
+          true);
+
+      // fail scenarios
+
+      // not encrypted
+      FakeMatrixApi.calledEndpoints.clear();
+      await client.database.setLastSentMessageUserDeviceKey(
+          json.encode({
+            'type': 'm.foxies',
+            'content': {
+              'floof': 'foxhole',
+            },
+          }),
+          client.id,
+          userId,
+          deviceId);
+      event = ToDeviceEvent(
+        sender: userId,
+        type: 'm.dummy',
+        content: {},
+        encryptedContent: null,
+      );
+      await client.encryption.olmManager.handleToDeviceEvent(event);
+      expect(
+          FakeMatrixApi.calledEndpoints.keys.any(
+              (k) => k.startsWith('/client/r0/sendToDevice/m.room.encrypted')),
+          false);
+
+      // device not found
+      FakeMatrixApi.calledEndpoints.clear();
+      await client.database.setLastSentMessageUserDeviceKey(
+          json.encode({
+            'type': 'm.foxies',
+            'content': {
+              'floof': 'foxhole',
+            },
+          }),
+          client.id,
+          userId,
+          deviceId);
+      event = ToDeviceEvent(
+        sender: userId,
+        type: 'm.dummy',
+        content: {},
+        encryptedContent: {
+          'sender_key': 'invalid',
+        },
+      );
+      await client.encryption.olmManager.handleToDeviceEvent(event);
+      expect(
+          FakeMatrixApi.calledEndpoints.keys.any(
+              (k) => k.startsWith('/client/r0/sendToDevice/m.room.encrypted')),
+          false);
+    });
+
     test('dispose client', () async {
       await client.dispose(closeDatabase: true);
     });

test/encryption/online_key_backup_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/encryption/ssss_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/event_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/fake_client.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/fake_database.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/fake_matrix_api.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/fake_matrix_localizations.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/markdown_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_api_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_default_localizations.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_exception_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_file_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_id_string_extension_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/matrix_localizations_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/mxc_uri_extension_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/room_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/states_map_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/sync_filter_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/timeline_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/uia_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify

test/user_test.dart

@@ -1,5 +1,5 @@
 /*
- *   Ansible inventory script used at Famedly GmbH for managing many hosts
+ *   Famedly Matrix SDK
  *   Copyright (C) 2019, 2020 Famedly GmbH
  *
  *   This program is free software: you can redistribute it and/or modify