decryptBlock method

@override List<int> decryptBlock(List<int> src, [ List<int>? dst ])

This method takes a source block of ciphertext, decrypts it using the decryption key schedule, and returns the resulting plaintext. Optionally, you can provide a destination block (dst) to write the decrypted data into. If not provided, a new List

Parameters:

• src: The source block of ciphertext to be decrypted, which must have a length of 16 bytes.
• dst: An optional destination block to store the decrypted plaintext. If not provided, a new block is created.

Throws:

• ArgumentException if the source or destination block size is not 16 bytes.
• StateError if the instance was created with the noDecryption option, indicating that decryption is not supported by this instance.

Returns:

• The decrypted plaintext block as a List

Implementation

@override
List<int> decryptBlock(List<int> src, [List<int>? dst]) {
  final out = dst ?? List<int>.filled(blockSize, 0);
  if (src.length != blockSize) {
    throw const ArgumentException("AES: invaiid source block size");
  }
  if (out.length != blockSize) {
    throw const ArgumentException("AES: invalid destination block size");
  }

  if (_decKey == null) {
    throw const MessageException(
        "AES: decrypting with an instance created with noDecryption option");
  } else {
    _lib.decryptBlock(_decKey!, src, out);
  }

  return out;
}