static void Main(string[] args)
{
byte[] msg;
IPEndPoint listenEndPoint;
TcpListener server = null;
TcpClient client = null;
NetworkStream netStream = null;
ProtocolSI protocol = null;
AesCryptoServiceProvider aes = null;
SymmetricsSI symmetricsSI = null;
RSACryptoServiceProvider rsaClient = null;
RSACryptoServiceProvider rsaServer = null;
try
{
Console.WriteLine("SERVER");
#region Defenitions
// algortimos assimétricos
rsaClient = new RSACryptoServiceProvider();
rsaServer = new RSACryptoServiceProvider();
// algoritmos simétrico a usar...
aes = new AesCryptoServiceProvider();
symmetricsSI = new SymmetricsSI(aes);
// Binding IP/port
listenEndPoint = new IPEndPoint(IPAddress.Any, 13000);
// Client/Server Protocol to SI
protocol = new ProtocolSI();
#endregion
Console.WriteLine(SEPARATOR);
#region TCP Listner
// Start TcpListener
server = new TcpListener(listenEndPoint);
server.Start();
// Waits for a client connection (bloqueant wait)
Console.Write("waiting for a connection... ");
client = server.AcceptTcpClient();
netStream = client.GetStream();
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exhange Public Keys
// Receive client public key
Console.Write("waiting for client public key...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
rsaClient.FromXmlString(protocol.GetStringFromData());
Console.WriteLine("ok");
// Send public key...
Console.Write("Sending public key... ");
msg = protocol.Make(ProtocolSICmdType.PUBLIC_KEY, rsaServer.ToXmlString(false));
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exchange Secret Key
// Receive key
Console.Write("waiting for key...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
aes.Key = rsaServer.Decrypt(protocol.GetData(), true);
Console.WriteLine("ok");
Console.WriteLine(" Received: {0} ", ProtocolSI.ToHexString(aes.Key));
// Answer with a ACK
Console.Write("Sending a ACK... ");
msg = protocol.Make(ProtocolSICmdType.ACK);
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
// Receive iv
Console.Write("waiting for iv...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
aes.IV = rsaServer.Decrypt(protocol.GetData(), true);
Console.WriteLine("ok");
Console.WriteLine(" Received: {0} ", ProtocolSI.ToHexString(aes.IV));
// Answer with a ACK
Console.Write("Sending a ACK... ");
msg = protocol.Make(ProtocolSICmdType.ACK);
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Exchange Data (Secure channel)
// Receive the cipher
Console.Write("waiting for data...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
byte[] encryptedData = protocol.GetData();
//byte[] data = symmetricsSI.Decrypt(encryptedData);
Console.WriteLine("ok");
//Console.WriteLine(" Encrypted: {0}", ProtocolSI.ToHexString(encryptedData));
//Console.WriteLine(" Data: {0} = {1}", ProtocolSI.ToString(data), ProtocolSI.ToHexString(data));
// Answer with a ACK
Console.Write("Sending a ACK... ");
msg = protocol.Make(ProtocolSICmdType.ACK);
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("ok");
#endregion
Console.WriteLine(SEPARATOR);
#region Verify Digital Signature
Console.Write("waiting for digital signature...");
netStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
var signature = protocol.GetData();
//encryptedData[0] = 0;
bool status = rsaClient.VerifyData(encryptedData, new SHA256CryptoServiceProvider(), signature);
Console.WriteLine("OK");
Console.WriteLine("STATUS SIGNATURE = " + status);
Console.Write("Sending (N)ACK...");
if (status)
{
msg = protocol.Make(ProtocolSICmdType.ACK);
}
else
{
msg = protocol.Make(ProtocolSICmdType.NACK);
}
netStream.Write(msg, 0, msg.Length);
Console.WriteLine("OK");
if (status)
{
byte[] data = symmetricsSI.Decrypt(encryptedData);
Console.WriteLine("ok");
Console.WriteLine(" Encrypted: {0}", ProtocolSI.ToHexString(encryptedData));
Console.WriteLine(" Data: {0} = {1}", ProtocolSI.ToString(data), ProtocolSI.ToHexString(data));
}
#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();
}
if (server != null)
{
server.Stop();
}
Console.WriteLine(SEPARATOR);
Console.WriteLine("Connection with client was closed.");
}
Console.WriteLine(SEPARATOR);
Console.Write("End: Press a key...");
Console.ReadKey();
}
ClientWithProtocolSI()
{
try
{
Console.Write("<-> Starting client... ");
clientRsaProvider = new RSACryptoServiceProvider();
aes = new AesCryptoServiceProvider();
ssInstance = new SymmetricsSI(aes);
Console.WriteLine("done");
Console.Write("==> Connecting to the server... ");
tcpClient = new TcpClient(SERVER_HOSTNAME, SERVER_PORT);
networkStream = tcpClient.GetStream();
Console.WriteLine("done");
protocol = new ProtocolSI();
// Exchanging RSA public keys
Console.Write("--> Sending RSA client public key... ");
messageBytes = protocol.Make(ProtocolSICmdType.PUBLIC_KEY, clientRsaProvider.ToXmlString(false));
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.Write("<-- Receiving RSA server public key... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
serverRsaProvider = new RSACryptoServiceProvider();
serverRsaProvider.FromXmlString(protocol.GetStringFromData());
Console.WriteLine("done");
// Sending AES secrets
Console.Write("--> Sending AES key... ");
messageBytes = protocol.Make(ProtocolSICmdType.SECRET_KEY, serverRsaProvider.Encrypt(aes.Key, true));
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.WriteLine("-- Sent: {0} .", ProtocolSI.ToHexString(aes.Key));
Console.Write("<-- Waiting for an ACK command... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("done");
Console.Write("--> Sending AES IV... ");
messageBytes = protocol.Make(ProtocolSICmdType.IV, serverRsaProvider.Encrypt(aes.IV, true));
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.WriteLine("-- Sent: {0} .", ProtocolSI.ToHexString(aes.IV));
Console.Write("<-- Waiting for an ACK command... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
Console.WriteLine("done");
Console.Write("--> Requesting account balance... ");
byte[] clearData = BitConverter.GetBytes(CLIENT_ACCOUNT_ID);
byte[] encryptedData = ssInstance.Encrypt(clearData);
messageBytes = protocol.Make(ProtocolSICmdType.SYM_CIPHER_DATA, encryptedData);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.WriteLine("-- Account ID: {0} = {1} .", BitConverter.ToInt32(clearData, 0).ToString(), ProtocolSI.ToHexString(clearData));
Console.WriteLine("-- Sent Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.Write("<-- Waiting for the account balance... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
encryptedData = protocol.GetData();
clearData = ssInstance.Decrypt(encryptedData);
double balance = BitConverter.ToDouble(clearData, 0);
Console.WriteLine("done");
Console.WriteLine(" -- Received Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.WriteLine(" -- Account Balance: {0} = {1} .", balance.ToString(), ProtocolSI.ToHexString(clearData));
Console.Write("--> Requesting digital signature... ");
// missing something like ProtocolSICmdType.REQUEST_DIGITAL_SIGNATURE
// due to that, I used ProtocolSICmdType.DIGITAL_SIGNATURE as a REQUEST_DIGITAL_SIGNATURE
// and the received digital signature is actually ProtocolSICmdType.SYM_CIPHER_DATA
// because its encrypted with a symmetric algorithm.
messageBytes = protocol.Make(ProtocolSICmdType.DIGITAL_SIGNATURE);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.Write("<-- Receiving encrypted digital signature... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.Length);
encryptedData = protocol.GetData();
byte[] signature = ssInstance.Decrypt(encryptedData);
Console.WriteLine("done");
Console.WriteLine(" -- Received Data: {0} .", ProtocolSI.ToHexString(encryptedData));
Console.WriteLine(" -- Signature: {0} .", Convert.ToBase64String(signature));
Console.Write("<-> Verify digital signature... ");
// use previous clearData which is the balance converted to bytes
bool signatureStatus =
serverRsaProvider.VerifyData(clearData, new SHA256CryptoServiceProvider(), signature);
Console.WriteLine(signatureStatus ? "verified" : "failed");
Console.Write("--> Sending digital signature status... ");
messageBytes = protocol.Make(signatureStatus ? ProtocolSICmdType.ACK : ProtocolSICmdType.NACK);
networkStream.Write(messageBytes, 0, messageBytes.Length);
Console.WriteLine("done");
Console.Write("<-- Waiting for an EOT command... ");
networkStream.Read(protocol.Buffer, 0, protocol.Buffer.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();
Console.WriteLine("done");
}
}
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");
}
}