decryptWithKey static method

String? decryptWithKey(Uint8List encryptionKey, Uint8List hmacKey, String b64str, { bool checkHmac = true, })

Decrypts the input text by using a 32 byte length key and 16 byte length initialization vector.

Implementation

static String? decryptWithKey(
    Uint8List encryptionKey, Uint8List hmacKey, String b64str,
    {bool checkHmac = true}) {
  final data = base64.decode(b64str);
  final components = RNCryptorComponents.fromBuffer(data);
  if (components == null || components.header.options != 0) {
    return null;
  }
  if (checkHmac) {
    var hmacData =
        data.sublist(0, data.length - RNCryptorSettings.hmacLength);
    var hmac = _generateHmac(hmacData, hmacKey);
    if (!ListEquality().equals(components.hmac, hmac)) {
      return null;
    }
  }
  try {
    return _decryptCore(
        encryptionKey, components.header.iv, components.cipherText);
  } catch (e) {
    return null;
  }
}