public ClientHandler(TcpClient connection)
{
this.dhKeyHelper = new DHHelper.DHHelper(false);
this.clientConnection = connection;
this.authHelper = new AuthenticationHelper();
this.userName = String.Empty;
this.isAuthenticated = false;
this.socketReader = new StreamReader(this.clientConnection.GetStream());
this.socketWriter = new StreamWriter(this.clientConnection.GetStream());
this.probeTimeSpan = new TimeSpan(0, 0, Helper.GlobalConstants.ProbeInterval);
}
private void Talk()
{
//Set up a shared secret key using DH algorithm
//Get the public exponent and base prime
AuthTimeOut = new System.Timers.Timer(Helper.GlobalConstants.TimeOutForAuthentication * 1000);
AuthTimeOut.Elapsed += new ElapsedEventHandler(AuthTimeOut_Elapsed);
try
{
if (SetupDHSharedKey())
{
AuthTimeOut.Enabled = false;
AuthTimeOut.Interval = Helper.GlobalConstants.TimeOutForAuthentication * 1000;
AuthTimeOut.Enabled = true;
string currentLine;
int noOfTries = 3;
while (noOfTries > 0 && !this.isAuthenticated && this.isClientAlive)
{
currentLine = GetDecryptedLine();
string[] credentials = currentLine.Split(null);
if (credentials.Length == 2)
{
AuthenticationHelper authHelper = new AuthenticationHelper();
//If the user name and password are valid for the user
if (authHelper.IsValid(credentials[0], credentials[1]))
{
this.isAuthenticated = true;
//Tell client that Authentication is sucessfull
AuthTimeOut.Enabled = false;
AuthTimeOut.Dispose();
this.SendLineEncrypted(Helper.GlobalConstants.AuthSuccessMessage);
this.userName = credentials[0];
Logger.Logger.WriteInfo(String.Format("User \"{0}\" successfully authenticated", credentials[0]));
break;
}
}
if (noOfTries == 1)
{
this.SendLineEncrypted(Helper.GlobalConstants.AuthFailureNoRetryMessage);
}
else
{
this.SendLineEncrypted(Helper.GlobalConstants.AuthFailureMessage);
}
Logger.Logger.WriteInfo(String.Format("User \"{0}\" failed to authenticate. Trials remained: {1}", credentials[0], noOfTries-1));
noOfTries--;
}
if (this.isAuthenticated)
{
this.probeAliveTimer = new System.Timers.Timer(Helper.GlobalConstants.ProbeInterval * 1000);//this.SendAliveProbe, Helper.GlobalConstants.ProbeMessage, this.probeTimeSpan, this.probeTimeSpan);
this.probeAliveTimer.Elapsed += new ElapsedEventHandler(probeAliveTimer_Elapsed);
this.probeAliveTimer.AutoReset = true;
this.chatThread = new Thread(this.StartChat);
this.chatThread.Start();
this.probeAliveTimer.Start();
}
else
{
AuthTimeOut.Enabled = false;
AuthTimeOut.Dispose();
this.clientConnection.Close();
Logger.Logger.WriteError("Authentication failed");
}
}
}
catch (Exception e)
{
this.isClientAlive = false;
this.isAuthenticated = false;
this.clientConnection.Close();
Logger.Logger.WriteError("Problem occured while trying to establish a secure connection with the client");
Logger.Logger.WriteException(e);
}
if (!this.isAuthenticated)
{
this.isClientAlive = false;
this.isAuthenticated = false;
}
//Validate the provided user name and password
//Start Listining for any text from client
}