E2EEChat/lib/model/message.dart

import 'dart:convert';

import 'package:e2ee_chat/common/cipher.dart';
import 'package:json_annotation/json_annotation.dart';
import 'package:dash_chat/dash_chat.dart';
import 'package:encrypt/encrypt.dart';
import 'package:pointycastle/asymmetric/api.dart';

part 'message.g.dart';

@JsonSerializable()
class Message {
  Message(this.from, this.to, this.cipher, this.cipherText, this.publicKey, this.iv);

  factory Message.encrypt(String from, String to, String plaintext, String publicKey) {
    // TODO: encrypt
    String cipher = "";
    String cipherText = "";
    String publicKey = "";
    String iv = "";
    return Message(from, to, cipher, cipherText, publicKey, iv);
  }

  factory Message.fromJson(Map<String, dynamic> json) => _$MessageFromJson(json);
  Map<String, dynamic> toJson() => _$MessageToJson(this);

  String from;
  String to;
  String cipher;
  String cipherText;
  String publicKey;
  String iv;

  Future<ChatMessage?> get chatMessage async {
    ChatMessage? _message;
    final RSAPrivateKey? _privateKey = await getRSAPrivateKey(from);
    if (_privateKey != null) {
      final _publicKey = (await getRSAPublicKey(publicKey))!;
      final _rsaEncrypter = Encrypter(
          RSA(publicKey: _publicKey, privateKey: _privateKey));
      final _keyBase64 = _rsaEncrypter.decrypt64(cipher);
      final _key = Key.fromBase64(_keyBase64);
      final _iv = IV.fromBase64(iv);
      final _aesEncrypter = Encrypter(AES(_key));
      final _decrypted = _aesEncrypter.decrypt64(cipherText, iv: _iv);
      _message = ChatMessage.fromJson(jsonDecode(_decrypted));
    }
    return _message;
  }
}

/*
class GroupMessage {
  int id = 0;
  String plaintext = "";
  final user = ToOne<User>();
  final group = ToOne<Group>();

  @Transient()
  ChatMessage get chatMessage => ChatMessage.fromJson(jsonDecode(plaintext));
}
*/