feat: Implement all protobuf messages

lib/src/protobuf/omemo_authenticated_message.dart

@@ -0,0 +1,37 @@
+import 'package:omemo_dart/src/helpers.dart';
+import 'package:omemo_dart/src/protobuf/protobuf.dart';
+
+class OmemoAuthenticatedMessage {
+
+  const OmemoAuthenticatedMessage(this.mac, this.message);
+
+  factory OmemoAuthenticatedMessage.fromBuffer(List<int> data) {
+    var i = 0;
+    
+    // required bytes mac     = 1;
+    if (data[0] != fieldId(1, fieldTypeByteArray)) {
+      throw Exception();
+    }
+    final mac = data.sublist(2, i + 2 + data[1]);
+    i += data[1] + 2;
+
+    if (data[i] != fieldId(2, fieldTypeByteArray)) {
+      throw Exception();
+    }
+    final message = data.sublist(i + 2, i + 2 + data[i + 1]);
+
+    return OmemoAuthenticatedMessage(mac, message);
+  }
+  
+  final List<int> mac;
+  final List<int> message;
+
+  List<int> writeToBuffer() {
+    return concat([
+      [fieldId(1, fieldTypeByteArray), mac.length],
+      mac,
+      [fieldId(2, fieldTypeByteArray), message.length],
+      message,
+    ]);
+  }
+}

lib/src/protobuf/omemo_key_exchange.dart

@@ -0,0 +1,67 @@
+import 'package:omemo_dart/src/helpers.dart';
+import 'package:omemo_dart/src/protobuf/omemo_authenticated_message.dart';
+import 'package:omemo_dart/src/protobuf/protobuf.dart';
+
+class OmemoKeyExchange {
+
+  const OmemoKeyExchange(this.pkId, this.spkId, this.ik, this.ek, this.message);
+
+  factory OmemoKeyExchange.fromBuffer(List<int> data) {
+    var i = 0;
+
+    if (data[i] != fieldId(1, fieldTypeUint32)) {
+      throw Exception();
+    }
+    var decoded = decodeVarint(data, 1);
+    final pkId = decoded.n;
+    i += decoded.length + 1;
+
+    if (data[i] != fieldId(2, fieldTypeUint32)) {
+      throw Exception();
+    }
+    decoded = decodeVarint(data, i + 1);
+    final spkId = decoded.n;
+    i += decoded.length + 1;
+
+    if (data[i] != fieldId(3, fieldTypeByteArray)) {
+      throw Exception();
+    }
+    final ik = data.sublist(i + 2, i + 2 + data[i + 1]);
+    i += 2 + data[i + 1];
+
+    if (data[i] != fieldId(4, fieldTypeByteArray)) {
+      throw Exception();
+    }
+    final ek = data.sublist(i + 2, i + 2 + data[i + 1]);
+    i += 2 + data[i + 1];
+
+    if (data[i] != fieldId(5, fieldTypeByteArray)) {
+      throw Exception();
+    }
+    final message = OmemoAuthenticatedMessage.fromBuffer(data.sublist(i + 2));
+
+    return OmemoKeyExchange(pkId, spkId, ik, ek, message);
+  }
+  
+  final int pkId;
+  final int spkId;
+  final List<int> ik;
+  final List<int> ek;
+  final OmemoAuthenticatedMessage message;
+
+  List<int> writeToBuffer() {
+    final msg = message.writeToBuffer();
+    return concat([
+      [fieldId(1, fieldTypeUint32)],
+      encodeVarint(pkId),
+      [fieldId(2, fieldTypeUint32)],
+      encodeVarint(spkId),
+      [fieldId(3, fieldTypeByteArray), ik.length],
+      ik,
+      [fieldId(4, fieldTypeByteArray), ek.length],
+      ek,
+      [fieldId(5, fieldTypeByteArray), msg.length],
+      msg,
+    ]);
+  }
+}

test/protobuf_test.dart

@@ -1,4 +1,6 @@
 import 'package:omemo_dart/protobuf/schema.pb.dart';
+import 'package:omemo_dart/src/protobuf/omemo_authenticated_message.dart';
+import 'package:omemo_dart/src/protobuf/omemo_key_exchange.dart';
 import 'package:omemo_dart/src/protobuf/omemo_message.dart';
 import 'package:omemo_dart/src/protobuf/protobuf.dart';
 import 'package:test/test.dart';
@@ -107,4 +109,68 @@ void main() {
       expect(msg.ciphertext, <int>[]);
     });
   });
+
+  group('OMEMOAuthenticatedMessage', () {
+    test('Test encoding a message', () {
+      const msg = OmemoAuthenticatedMessage(<int>[1, 2, 3], <int>[4, 5, 6]);
+      final decoded = OMEMOAuthenticatedMessage.fromBuffer(msg.writeToBuffer());
+
+      expect(decoded.mac, <int>[1, 2, 3]);
+      expect(decoded.message, <int>[4, 5, 6]);
+    });
+    test('Test decoding a message', () {
+      final msg = OMEMOAuthenticatedMessage()
+        ..mac = <int>[1, 2, 3]
+        ..message = <int>[4, 5, 6];
+      final bytes = msg.writeToBuffer();
+      final decoded = OmemoAuthenticatedMessage.fromBuffer(bytes);
+
+      expect(decoded.mac, <int>[1, 2, 3]);
+      expect(decoded.message, <int>[4, 5, 6]);
+    });
+  });
+
+  group('OMEMOKeyExchange', () {
+    test('Test encoding a message', () {
+      const message = OmemoKeyExchange(
+        698,
+        245,
+        <int>[1, 4, 6],
+        <int>[4, 6, 7, 80],
+        OmemoAuthenticatedMessage(
+          <int>[5, 6, 8, 0],
+          <int>[4, 5, 7, 3, 2],
+        ),
+      );
+      final kex = OMEMOKeyExchange.fromBuffer(message.writeToBuffer());
+
+      expect(kex.pkId, 698);
+      expect(kex.spkId, 245);
+      expect(kex.ik, <int>[1, 4, 6]);
+      expect(kex.ek, <int>[4, 6, 7, 80]);
+
+      expect(kex.message.mac, <int>[5, 6, 8, 0]);
+      expect(kex.message.message, <int>[4, 5, 7, 3, 2]);
+    });
+    test('Test decoding a message', () {
+      final message = OMEMOAuthenticatedMessage()
+        ..mac = <int>[5, 6, 8, 0]
+        ..message = <int>[4, 5, 7, 3, 2];
+      final kex = OMEMOKeyExchange()
+        ..pkId = 698
+        ..spkId = 245
+        ..ik = <int>[1, 4, 6]
+        ..ek = <int>[4, 6, 7, 80]
+        ..message = message;
+      final decoded = OmemoKeyExchange.fromBuffer(kex.writeToBuffer());
+
+      expect(decoded.pkId, 698);
+      expect(decoded.spkId, 245);
+      expect(decoded.ik, <int>[1, 4, 6]);
+      expect(decoded.ek, <int>[4 ,6 ,7 , 80]);
+
+      expect(decoded.message.mac, <int>[5, 6, 8, 0]);
+      expect(decoded.message.message, <int>[4, 5, 7, 3, 2]);
+    });
+  });
 }