decrypt method

Uint8List decrypt({
  1. required Uint8List data,
  2. required Uint8List key,
  3. Uint8List? iv,
  4. BLOCK_CIPHER_MODE mode = BLOCK_CIPHER_MODE.CBC,
})

Implementation

Uint8List decrypt(
    {required Uint8List data,
    required Uint8List key,
    Uint8List? iv,
    BLOCK_CIPHER_MODE mode = BLOCK_CIPHER_MODE.CBC}) {
  _log.finest(
      "AESCipher.decrypt; data size: ${data.length}, data: ${data.hex()}");
  _log.sdVerbose(
      "AESCipher.decrypt; data: ${data.hex()}, key size: ${key.length}, key: ${key.hex()}");

  if (key.length != size) {
    _log.error(
        "AESCipher.decrypt; AES${size * 8} key length must be ${size * 8} bits.");
    throw AESCipherError(
        "AESCipher.decrypt; AES${size * 8} key length must be ${size * 8} bits.");
  }

  if (iv != null) {
    _log.sdVerbose(
        "AESCipher.decrypt; iv size: ${iv.length}, iv: ${iv.hex()}");
    if (iv.length != AES_BLOCK_SIZE) {
      _log.error("AESCipher.encrypt; iv length is not 128 bits.");
      throw AESCipherError("AESCipher.encrypt; iv length is not 128 bits.");
    }
  } else {
    iv = Uint8List(AES_BLOCK_SIZE);
    _log.sdVerbose("AESCipher.decrypt; iv is null");
  }

  var cipher;
  if (mode == BLOCK_CIPHER_MODE.CBC)
    cipher = CBCBlockCipher(_factory())
      ..init(false, ParametersWithIV(KeyParameter(key), iv));
  else
    cipher = ECBBlockCipher(_factory())..init(false, KeyParameter(key));
  return Uint8List.fromList(
      _processBlocks(cipher: cipher, data: data).toList());
}