utils.dart

static Future<String> asymmetricEncript(String text) async {
    String key = '';
    if (kIsWeb) {
      PickedFile localFile = PickedFile('assets/key/pdv.pem');
      key = (await localFile.readAsString());
    } else {
      key = await rootBundle.loadString('assets/key/pdv.pem');
    }
    final parser = RSAKeyParser();
    final publicKey = parser.parse(key) as RSAPublicKey;
    final encrypter = Encrypter(RSA(publicKey: publicKey));
    final encrypted = encrypter.encrypt(text);
    return (encrypted.base64);
  }

  static Future<String> asymmetricDencript(String text) async {
    String key = '';
    if (kIsWeb) {
      PickedFile localFile = PickedFile('assets/key/pdv.key');
      key = (await localFile.readAsString());
    } else {
      key = await rootBundle.loadString('assets/key/pdv.key');
    }

    final parser = RSAKeyParser();
    final private = parser.parse(key) as RSAPrivateKey;
    final encrypter = Encrypter(RSA(privateKey: private));
    final decriptedString = encrypter.decrypt(Encrypted(base64Decode(text)));
    return (decriptedString);
  }