private void check_response()
{
TcpClient client = null;
try
{
TcpListener listener = new TcpListener(IPAddress.Parse("127.0.0.1"), 9595);
listener.Start();
Byte[] bytes = new Byte[256];
String data = null;
while (true)
{
client = listener.AcceptTcpClient();
NetworkStream ns = client.GetStream();
Byte[] mode_bytes = new Byte[1];
int mode = ns.Read(mode_bytes, 0, mode_bytes.Length);
if (mode_bytes[0] == 0x01)
{
richTextBox1.Text += "Received encrypted msg. Try to decrypt: \n";
int bytes_read = ns.Read(buffer, 0, buffer.Length);
byte[] message = new byte[bytes_read];
Array.Copy(buffer, message, bytes_read);
BERelement mSeq = BERelement.DecodePacket(message);
BERelement sSeq = null;
sSeq = mSeq.Items[0];
var cert_name = sSeq.Items[0].Value;
var wrapped_key2 = sSeq.Items[1].Value;
var iv2 = sSeq.Items[2].Value;
var public_key_bytes = sSeq.Items[3].Value;
var cipher_text_bytes = sSeq.Items[4].Value;
MemoryStream ms = new MemoryStream(public_key_bytes);
BinaryFormatter bf = new BinaryFormatter();
Gost3410Parameters key_params = (Gost3410Parameters)bf.Deserialize(ms);
GostSharedSecretAlgorithm agree_key = csp.CreateAgree(key_params);
SymmetricAlgorithm gost = agree_key.Unwrap(wrapped_key2, GostKeyWrapMethod.CryptoProKeyWrap);
gost.IV = iv2;
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream,
gost.CreateDecryptor(), CryptoStreamMode.Write);
int bytesRead = cipher_text_bytes.Length;
cryptoStream.Write(cipher_text_bytes, 0, bytesRead);
cryptoStream.FlushFinalBlock();
byte[] plain_text_bytes = memoryStream.ToArray();
richTextBox1.Text += Encoding.ASCII.GetString(plain_text_bytes, 0, plain_text_bytes.Length) + "\n";
}
if (mode_bytes[0] == 0x02)
{
richTextBox1.Text += "Received sign. Try to check it: \n";
Gost3411CryptoServiceProvider hash = new Gost3411CryptoServiceProvider();
int bytes_read = ns.Read(buffer, 0, buffer.Length);
byte[] message = new byte[bytes_read];
Array.Copy(buffer, message, bytes_read);
BERelement mSeq = BERelement.DecodePacket(message);
BERelement sSeq = null;
sSeq = mSeq.Items[0];
var cert_name = sSeq.Items[0].Value;
var signed2 = sSeq.Items[1].Value;
var msg = sSeq.Items[2].Value;
int len = signed2.Length;
bool test = csp.VerifyData(msg, hash, signed2);
if (test)
{
richTextBox1.Text += "Подпись корректна.\r\n";
}
else
{
richTextBox1.Text += "Подпись некорректна.\r\n";
}
/*
* bool test = csp.VerifyData(message, hash, signed);
* if (test) richTextBox1.Text += "Подпись корректна.\r\n";
* else richTextBox1.Text += "Подпись некорректна.\r\n";
*
*/
}
if (mode_bytes[0] == 0x03)
{
richTextBox1.Text += "Received sign and encryption. Making magic: \n";
int bytes_read = ns.Read(buffer, 0, buffer.Length);
byte[] message = new byte[bytes_read];
Array.Copy(buffer, message, bytes_read);
BERelement mSeq = BERelement.DecodePacket(message);
BERelement sSeq = null;
sSeq = mSeq.Items[0];
var cert_name = sSeq.Items[0].Value;
var wrapped_key2 = sSeq.Items[1].Value;
var iv2 = sSeq.Items[2].Value;
var public_key_bytes = sSeq.Items[3].Value;
var cipher_text_bytes = sSeq.Items[4].Value;
MemoryStream ms = new MemoryStream(public_key_bytes);
BinaryFormatter bf = new BinaryFormatter();
Gost3410Parameters key_params = (Gost3410Parameters)bf.Deserialize(ms);
GostSharedSecretAlgorithm agree_key = csp.CreateAgree(key_params);
SymmetricAlgorithm gost = agree_key.Unwrap(wrapped_key2, GostKeyWrapMethod.CryptoProKeyWrap);
gost.IV = iv2;
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream,
gost.CreateDecryptor(), CryptoStreamMode.Write);
int bytesRead = cipher_text_bytes.Length;
cryptoStream.Write(cipher_text_bytes, 0, bytesRead);
cryptoStream.FlushFinalBlock();
byte[] plain_text_bytes = memoryStream.ToArray();
//check signature
Gost3411CryptoServiceProvider hash = new Gost3411CryptoServiceProvider();
//Array.Copy(buffer, message, bytes_read);
BERelement mSeq2 = BERelement.DecodePacket(plain_text_bytes);
BERelement sSeq2 = null;
sSeq2 = mSeq2.Items[0];
var cert_name2 = sSeq2.Items[0].Value;
var signed3 = sSeq2.Items[1].Value;
var msg2 = sSeq2.Items[2].Value;
int len2 = signed3.Length;
bool test = csp.VerifyData(msg2, hash, signed3);
richTextBox1.Text += "Полученное сообщение: "
+ Encoding.ASCII.GetString(msg2, 0, msg2.Length) + "\r\n";
if (test)
{
richTextBox1.Text += "Подпись корректна.\r\n";
}
else
{
richTextBox1.Text += "Подпись некорректна.\r\n";
}
}
int i;
while ((i = ns.Read(bytes, 0, bytes.Length)) != 0)
{
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
richTextBox1.Text = DateTime.Now.ToString() + "\n";
richTextBox1.Text += data;
}
client.Close();
}
}
catch (SocketException exception)
{
MessageBox.Show("SocketException: " + exception);
}
}
