protected override void InitCipher(byte[] iv, bool isEncrypt)
{
base.InitCipher(iv, isEncrypt);
_crypto?.Dispose();
if (cipherFamily == CipherFamily.Rc4Md5)
{
Span <byte> temp = stackalloc byte[keyLen + ivLen];
var realKey = new byte[MD5Length];
key.CopyTo(temp);
iv.CopyTo(temp.Slice(keyLen));
MD5Utils.Fast440(temp, realKey);
_crypto = StreamCryptoCreate.Rc4(realKey);
return;
}
_crypto = cipherFamily switch
{
CipherFamily.AesCfb => StreamCryptoCreate.AesCfb(isEncrypt, key, iv),
CipherFamily.Chacha20 => StreamCryptoCreate.ChaCha20(key, iv),
CipherFamily.Rc4 => StreamCryptoCreate.Rc4(key),
_ => throw new NotSupportedException()
};
}
public ChaCha20Poly1305Crypto(ReadOnlySpan <byte> key)
{
if (key.Length < KeySize)
{
throw new ArgumentException(@"Key length must be 32 bytes.", nameof(key));
}
_chacha20 = StreamCryptoCreate.ChaCha20(key);
_buffer = ArrayPool <byte> .Shared.Rent(32);
}
protected override IStreamCrypto CreateCrypto(bool isEncrypt, ReadOnlySpan <byte> key, ReadOnlySpan <byte> iv)
{
return(StreamCryptoCreate.ChaCha20(key, iv));
}
