omemo_dart/lib/src/protobuf/omemo_message.dart

76 lines
1.7 KiB
Dart

import 'package:omemo_dart/src/helpers.dart';
import 'package:omemo_dart/src/protobuf/protobuf.dart';
class OmemoMessage {
OmemoMessage();
factory OmemoMessage.fromBuffer(List<int> data) {
var i = 0;
// required uint32 n = 1;
if (data[0] != fieldId(1, fieldTypeUint32)) {
throw Exception();
}
var decode = decodeVarint(data, 1);
final n = decode.n;
i += decode.length + 1;
// required uint32 pn = 2;
if (data[i] != fieldId(2, fieldTypeUint32)) {
throw Exception();
}
decode = decodeVarint(data, i + 1);
final pn = decode.n;
i += decode.length + 1;
// required bytes dh_pub = 3;
if (data[i] != fieldId(3, fieldTypeByteArray)) {
throw Exception();
}
final dhPub = data.sublist(i + 2, i + 2 + data[i + 1]);
i += 2 + data[i + 1];
// optional bytes ciphertext = 4;
List<int>? ciphertext;
if (i < data.length) {
if (data[i] != fieldId(4, fieldTypeByteArray)) {
throw Exception();
}
ciphertext = data.sublist(i + 2, i + 2 + data[i + 1]);
}
return OmemoMessage()
..n = n
..pn = pn
..dhPub = dhPub
..ciphertext = ciphertext;
}
int? n;
int? pn;
List<int>? dhPub;
List<int>? ciphertext;
List<int> writeToBuffer() {
final data = concat([
[fieldId(1, fieldTypeUint32)],
encodeVarint(n!),
[fieldId(2, fieldTypeUint32)],
encodeVarint(pn!),
[fieldId(3, fieldTypeByteArray), dhPub!.length],
dhPub!,
]);
if (ciphertext != null) {
return concat([
data,
[fieldId(4, fieldTypeByteArray), ciphertext!.length],
ciphertext!,
]);
}
return data;
}
}