encryptWithPassword function

Future<Uint8List> encryptWithPassword(dynamic plainText, String password, String salt)

Encrypts the plainText with the given password and salt using AES-CBC.

The input data is converted to JSON and then encrypted. A random 16-byte IV (Initialization Vector) is generated and prepended to the encrypted data.

If the password is empty, the data is returned as UTF-8 encoded JSON without any actual encryption.

The encryption process is run in a separate Isolate to avoid blocking the main thread.

Implementation

Future<Uint8List> encryptWithPassword(
  dynamic plainText,
  String password,
  String salt,
) async {
  return Isolate.run(() {
    if (password.isEmpty) return utf8.encode(jsonEncode(plainText));

    final key = encrypt.Key(deriveKey(password, salt));
    final iv = encrypt.IV.fromLength(16);
    final encrypter = encrypt.Encrypter(
      encrypt.AES(key, mode: encrypt.AESMode.cbc),
    );

    final encrypted = encrypter.encrypt(jsonEncode(plainText), iv: iv);
    return Uint8List.fromList(iv.bytes + encrypted.bytes);
  });
}