/// <summary>
/// Creates and returns a stream containing decrypted data.
/// </summary>
/// <param name="input">A stream containing encrypted data.</param>
/// <returns>A stream with decrypted data.</returns>
public override Stream Decrypt(Stream input)
{
// check on view whether it's session's packet
if (input.ReadByte() == 0)
{
// continue the Security Session establishing
Stream outputStream = this.EstablishSession(input, false);
if (outputStream != null)
{
GenuineThreadPool.QueueUserWorkItem(new WaitCallback(this.SendMessage), outputStream, false);
}
return(null);
}
lock (this)
{
GenuineChunkedStream output = new GenuineChunkedStream(false);
byte[] sign = null;
int signSize = 0;
if (this.KeyedHashAlgorithm != null)
{
signSize = this.KeyedHashAlgorithm.HashSize / 8;
}
// decrypt the content and fetch the sign
if (this._decryptor != null)
{
CryptoStream cryptoStream = new CryptoStream(new FinishReadingStream(output), this._decryptor, CryptoStreamMode.Write);
sign = GenuineUtility.CopyStreamToStreamExceptSign(input, cryptoStream, signSize);
cryptoStream.FlushFinalBlock();
}
else
{
sign = GenuineUtility.CopyStreamToStreamExceptSign(input, output, signSize);
}
// check the sign
if (this.KeyedHashAlgorithm != null)
{
if (!ZeroProofAuthorizationUtility.CompareBuffers(sign, this.KeyedHashAlgorithm.ComputeHash(output), sign.Length))
{
throw GenuineExceptions.Get_Security_WrongSignature();
}
output.Position = 0;
}
output.ReleaseOnReadMode = true;
return(output);
}
}