decryptData function

String? decryptData(String? encryptedData, String key)

Implementation

String? decryptData(String? encryptedData, String key) {
  if (encryptedData == null || encryptedData.isEmpty) return null;

  if (key.isEmpty) {
    throw ArgumentError('Se requiere una clave (key) para desencriptar.');
  }

  final keyBytes = utf8.encode(key);
  if (keyBytes.length != 16 && keyBytes.length != 32) {
    throw ArgumentError(
        'La clave debe tener 16 (AES-128) o 32 (AES-256) caracteres.');
  }

  try {
    final encrKey = encrypt.Key(Uint8List.fromList(keyBytes));
    final aes = encrypt.AES(
      encrKey,
      mode: encrypt.AESMode.ecb,
      padding: 'PKCS7',
    );
    final encrypter = encrypt.Encrypter(aes);

    final encrypted = encrypt.Encrypted.fromBase64(encryptedData);
    final decrypted = encrypter.decrypt(encrypted, iv: null);
    return decrypted;
  } catch (e) {
    throw Exception('Error al desencriptar los datos: $e');
  }
}