ServerWithProtocolSI()
{
CreateAccounts();
try
{
Console.Write("<-> Starting server... ");
serverRsaProvider = new RSACryptoServiceProvider();
tcpListener = new TcpListener(IPAddress.Any, SERVER_PORT);
tcpListener.Start();
Console.WriteLine("done");
// client scope: this could be wrapped into a loop
{
Console.Write("<== Waiting for the client to connect... ");
tcpClient = tcpListener.AcceptTcpClient();
networkStream = tcpClient.GetStream();
Console.WriteLine("done");
protocol = new ProtocolSI();
// Exchanging RSA public keys
Console.Write("<-- Receiving RSA client public key... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
clientRsaProvider = new RSACryptoServiceProvider();
clientRsaProvider.FromXmlString(protocol.GetStringFromData());
Console.WriteLine("done");
Console.Write("--> Sending RSA server public key... ");
messageBytes = protocol.Make(ProtocolSICmdType.PUBLIC_KEY, serverRsaProvider.ToXmlString(false));
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
// Receiving AES secrets
Console.Write("<-- Receiving AES key... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
aes = new AesCryptoServiceProvider();
ssInstance = new SymmetricsSI(aes);
aes.Key = serverRsaProvider.Decrypt(protocol.GetData(), true);
Console.WriteLine("done");
Console.WriteLine(" -- Received: {0} .", ProtocolSI.ToHexString(aes.Key));
Console.Write("--> Sending an ACK command... ");
messageBytes = protocol.Make(ProtocolSICmdType.ACK);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.Write("<-- Receiving AES IV... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
aes.IV = serverRsaProvider.Decrypt(protocol.GetData(), true);
Console.WriteLine("done");
Console.WriteLine(" -- Received: {0} .", ProtocolSI.ToHexString(aes.IV));
Console.Write("--> Sending an ACK command... ");
messageBytes = protocol.Make(ProtocolSICmdType.ACK);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.Write("<-- Waiting for an account balance request... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
byte[] encryptedData = protocol.GetData();
byte[] clearData = ssInstance.Decrypt(encryptedData);
int accountId = BitConverter.ToInt32(clearData, 0);
Console.WriteLine("done");
Console.WriteLine(" -- Received Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.WriteLine(" -- Account ID: {0} = {1} .", accountId.ToString(), ProtocolSI.ToHexString(clearData));
Console.Write("--> Sending the account balance... ");
clearData = BitConverter.GetBytes(accounts[accountId]);
encryptedData = ssInstance.Encrypt(clearData);
messageBytes = protocol.Make(ProtocolSICmdType.SYM_CIPHER_DATA, encryptedData);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.WriteLine("-- Account Balance: {0} = {1} .", BitConverter.ToDouble(clearData, 0).ToString(), ProtocolSI.ToHexString(clearData));
Console.WriteLine("-- Sent Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.Write("<-- Waiting for a digital signature request... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("done");
Console.Write("--> Sending digital signature... ");
// use previous clearData which is the balance converted to bytes
byte[] signature = serverRsaProvider.SignData(clearData, new SHA256CryptoServiceProvider());
encryptedData = ssInstance.Encrypt(signature);
messageBytes = protocol.Make(ProtocolSICmdType.SYM_CIPHER_DATA, encryptedData);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.WriteLine("-- Signature: {0} .", Convert.ToBase64String(signature));
Console.WriteLine("-- Sent Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.Write("<-- Receiving digital signature status... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine(protocol.GetCmdType() == ProtocolSICmdType.ACK
? "verified"
: "failed");
Console.Write("--> Sending EOT... ");
messageBytes = protocol.Make(ProtocolSICmdType.EOT);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
}
}
catch (Exception ex)
when(
ex is SocketException ||
ex is CryptographicException
)
{
Console.WriteLine("\n===\nException: {0}\nStackTrace:\n{1}\n", ex.Message, ex.StackTrace);
}
finally
{
Console.Write("<-> Closing all the connections and streams... ");
networkStream?.Dispose();
tcpClient?.Close();
tcpListener?.Stop();
Console.WriteLine("done");
}
}
static void Main(string[] args)
{
byte[] msg;
IPEndPoint serverEndPoint;
TcpClient client = null;
NetworkStream netStream = null;
ProtocolSI protocol = null;
AesCryptoServiceProvider aes = null;
SymmetricsSI symmetricsSI = null;
RSACryptoServiceProvider rsaClient = null;
RSACryptoServiceProvider rsaServer = null;
try
{
Console.WriteLine("CLIENT");
#region Defenitions
// algortimos assimétricos
rsaClient = new RSACryptoServiceProvider();
rsaServer = new RSACryptoServiceProvider();
// algoritmos simétrico a usar...
aes = new AesCryptoServiceProvider();
symmetricsSI = new SymmetricsSI(aes);
// Client/Server Protocol to SI
protocol = new ProtocolSI();
// Defenitions for TcpClient: IP:port (127.0.0.1:13000)
serverEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 13000);
#endregion
Console.WriteLine(SEPARATOR);
#region TCP Connection
// Connects to Server ...
Console.Write("Connecting to server... ");
client = new TcpClient();
client.Connect(serverEndPoint);
netStream = client.GetStream();
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exchange Public Keys
// Send public key...
Console.Write("Sending public key... ");
msg = protocol.Make(ProtocolSICmdType.PUBLIC_KEY, rsaClient.ToXmlString(false));
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
// Receive server public key
Console.Write("waiting for server public key...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
rsaServer.FromXmlString(protocol.GetStringFromData());
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exchange Secret Key
// Send key...
Console.Write("Sending key... ");
msg = protocol.Make(ProtocolSICmdType.SECRET_KEY, rsaServer.Encrypt(aes.Key, true));
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
Console.WriteLine(" Sent: " + ProtocolSI.ToHexString(aes.Key));
// Receive ack
Console.Write("waiting for ACK...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("ok");
// Send iv...
Console.Write("Sending iv... ");
msg = protocol.Make(ProtocolSICmdType.IV, rsaServer.Encrypt(aes.IV, true));
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
Console.WriteLine(" Sent: " + ProtocolSI.ToHexString(aes.IV));
// Receive ack
Console.Write("waiting for ACK...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exchange Data (Secure channel)
// Send data...
byte[] clearData = Encoding.UTF8.GetBytes("hello world!!!");
Console.Write("Sending data... ");
byte[] encryptedData = symmetricsSI.Encrypt(clearData);
msg = protocol.Make(ProtocolSICmdType.DATA, encryptedData);
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
Console.WriteLine(" Data: {0} = {1}", ProtocolSI.ToString(clearData), ProtocolSI.ToHexString(clearData));
Console.WriteLine(" Encrypted: {0}", ProtocolSI.ToHexString(encryptedData));
// Receive answer from server
Console.Write("waiting for ACK...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("ok");
#endregion
#region Send Digital signature
Console.Write("Sending digital signature... ");
msg = protocol.Make(ProtocolSICmdType.DIGITAL_SIGNATURE, rsaClient.SignData(encryptedData, new SHA256CryptoServiceProvider()));
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("OK");
Console.Write("waiting... ");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine(protocol.GetCmdType());
#endregion
} catch (Exception ex)
{
Console.WriteLine(SEPARATOR);
Console.WriteLine("Exception: {0}", ex.ToString());
}
finally
{
// Close connections
if (netStream != null)
{
netStream.Dispose();
}
if (client != null)
{
client.Close();
}
Console.WriteLine(SEPARATOR);
Console.WriteLine("Connection with server was closed.");
}
Console.WriteLine(SEPARATOR);
Console.Write("End: Press a key...");
Console.ReadKey();
}
