twonly-app/lib/src/model/json/signal_identity.dart

import 'dart:typed_data';
import 'package:json_annotation/json_annotation.dart';
import 'dart:convert';
part 'signal_identity.g.dart';

@JsonSerializable()
class SignalIdentity {
  const SignalIdentity({
    required this.identityKeyPairU8List,
    required this.registrationId,
  });

  final int registrationId;

  @Uint8ListConverter()
  final Uint8List identityKeyPairU8List;
  factory SignalIdentity.fromJson(Map<String, dynamic> json) =>
      _$SignalIdentityFromJson(json);
  Map<String, dynamic> toJson() => _$SignalIdentityToJson(this);
}

class Uint8ListConverter implements JsonConverter<Uint8List, String> {
  const Uint8ListConverter();
  @override
  Uint8List fromJson(String json) {
    return base64Decode(json);
  }

  @override
  String toJson(Uint8List object) {
    return base64Encode(object);
  }
}