NegotiateStream Class

using System;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Text;

namespace Examples.NegotiateStreamExample
{
    public class ASynchronousAuthenticatingTcpClient 
    {   
        static TcpClient client = null;

        public static void Main(String[] args)  
        {
            // Establish the remote endpoint for the socket.
            // For this example, use the local machine.
            IPHostEntry ipHostInfo = Dns.GetHostEntry("localhost");
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            // Client and server use port 11000. 
            IPEndPoint remoteEP = new IPEndPoint(ipAddress, 11000);
            // Create a TCP/IP socket.
            client = new TcpClient();
            // Connect the socket to the remote endpoint.
            client.Connect(remoteEP);
            Console.WriteLine("Client connected to {0}.", remoteEP.ToString());
            // Ensure the client does not close when there is 
            // still data to be sent to the server.
            client.LingerState = (new LingerOption(true, 0));
            // Request authentication.
            NetworkStream clientStream = client.GetStream();
            NegotiateStream authStream = new NegotiateStream(clientStream, false); 
            // Pass the NegotiateStream as the AsyncState object 
            // so that it is available to the callback delegate.
            IAsyncResult ar = authStream.BeginAuthenticateAsClient(
                new AsyncCallback(EndAuthenticateCallback),
                authStream
                );
            Console.WriteLine("Client waiting for authentication...");
            // Wait until the result is available.
            ar.AsyncWaitHandle.WaitOne();
            // Display the properties of the authenticated stream.
            AuthenticatedStreamReporter.DisplayProperties(authStream);
            // Send a message to the server.
            // Encode the test data into a byte array.
            byte[] message = Encoding.UTF8.GetBytes("Hello from the client.");
            ar = authStream.BeginWrite(message, 0, message.Length,
                new AsyncCallback(EndWriteCallback),
                authStream);
            ar.AsyncWaitHandle.WaitOne();
            Console.WriteLine("Sent {0} bytes.", message.Length);
            // Close the client connection.
            authStream.Close();
            Console.WriteLine("Client closed.");
        }
        // The following method is called when the authentication completes.
        public static void EndAuthenticateCallback (IAsyncResult ar)
        {
            Console.WriteLine("Client ending authentication...");
            NegotiateStream authStream = (NegotiateStream) ar.AsyncState;
            Console.WriteLine("ImpersonationLevel: {0}", authStream.ImpersonationLevel);

            // End the asynchronous operation.
            authStream.EndAuthenticateAsClient(ar);
        }
        // The following method is called when the write operation completes.
        public static void EndWriteCallback (IAsyncResult ar)
        {
            Console.WriteLine("Client ending write operation...");
            NegotiateStream authStream = (NegotiateStream) ar.AsyncState;

            // End the asynchronous operation.
            authStream.EndWrite(ar);
        }
    }

    // The following class displays the properties of an authenticatedStream.
    public class AuthenticatedStreamReporter
{
    public static void DisplayProperties(AuthenticatedStream stream)
   {
        Console.WriteLine("IsAuthenticated: {0}", stream.IsAuthenticated);
        Console.WriteLine("IsMutuallyAuthenticated: {0}", stream.IsMutuallyAuthenticated);
        Console.WriteLine("IsEncrypted: {0}", stream.IsEncrypted);
        Console.WriteLine("IsSigned: {0}", stream.IsSigned);
        Console.WriteLine("IsServer: {0}", stream.IsServer);
    }
}
}

using System;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Authentication;
using System.Security.Principal;
using System.Text;
using System.IO;
using System.Threading;

namespace Examples.NegotiateStreamExample
{
    public class AsynchronousAuthenticatingTcpListener 
    {
        public static void Main() 
        {   
            // Create an IPv4 TCP/IP socket. 
            TcpListener listener = new TcpListener(IPAddress.Any, 11000);
            // Listen for incoming connections.
            listener.Start();
            while (true) 
            {
                TcpClient clientRequest = null;
                // Application blocks while waiting for an incoming connection.
                // Type CNTL-C to terminate the server.
                clientRequest = listener.AcceptTcpClient();
                Console.WriteLine("Client connected.");
                // A client has connected. 
                try
                {
                    AuthenticateClient (clientRequest);
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                    continue;
                }

            }

        }
        public static void AuthenticateClient(TcpClient clientRequest)
        {
            NetworkStream stream = clientRequest.GetStream(); 
            // Create the NegotiateStream.
            NegotiateStream authStream = new NegotiateStream(stream, false); 
            // Save the current client and NegotiateStream instance 
            // in a ClientState object.
            ClientState cState = new ClientState(authStream, clientRequest);
            // Listen for the client authentication request.
            authStream.BeginAuthenticateAsServer (
                new AsyncCallback(EndAuthenticateCallback),
                cState
                );
            // Wait until the authentication completes.
            cState.Waiter.WaitOne();
            cState.Waiter.Reset();
            authStream.BeginRead(cState.Buffer, 0, cState.Buffer.Length, 
                   new AsyncCallback(EndReadCallback), 
                   cState);
            cState.Waiter.WaitOne();
            // Finished with the current client.
            authStream.Close();
            clientRequest.Close();
        }
        // The following method is invoked by the
        // BeginAuthenticateAsServer callback delegate.

        public static void EndAuthenticateCallback (IAsyncResult ar)
        {
            // Get the saved data.
            ClientState cState = (ClientState) ar.AsyncState;
            TcpClient clientRequest = cState.Client;
            NegotiateStream authStream = (NegotiateStream) cState.AuthenticatedStream;
            Console.WriteLine("Ending authentication.");
            // Any exceptions that occurred during authentication are
            // thrown by the EndAuthenticateAsServer method.
            try 
            {
                // This call blocks until the authentication is complete.
                authStream.EndAuthenticateAsServer(ar);
            }
            catch (AuthenticationException e)
            {
                Console.WriteLine(e);
                Console.WriteLine("Authentication failed - closing connection.");
                cState.Waiter.Set();
                return;
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
                Console.WriteLine("Closing connection.");
                cState.Waiter.Set();
                return;
            }
            // Display properties of the authenticated client.
            IIdentity id = authStream.RemoteIdentity;
            Console.WriteLine("{0} was authenticated using {1}.", 
                id.Name, 
                id.AuthenticationType
                );
            cState.Waiter.Set();

    }
        public static void EndReadCallback(IAsyncResult ar)
        {
            // Get the saved data.
            ClientState cState = (ClientState) ar.AsyncState;
            TcpClient clientRequest = cState.Client;
            NegotiateStream authStream = (NegotiateStream) cState.AuthenticatedStream; 
            // Get the buffer that stores the message sent by the client.
            int bytes = -1;
            // Read the client message.
            try
            {
                    bytes = authStream.EndRead(ar);
                    cState.Message.Append(Encoding.UTF8.GetChars(cState.Buffer, 0, bytes));
                    if (bytes != 0)
                    {
                         authStream.BeginRead(cState.Buffer, 0, cState.Buffer.Length, 
                               new AsyncCallback(EndReadCallback), 
                               cState);
                               return;
                 }
            }
            catch (Exception e)
            {
                // A real application should do something
                // useful here, such as logging the failure.
                Console.WriteLine("Client message exception:");
                Console.WriteLine(e);
                cState.Waiter.Set();
                return;
            }
            IIdentity id = authStream.RemoteIdentity;
            Console.WriteLine("{0} says {1}", id.Name, cState.Message.ToString());
            cState.Waiter.Set();
        }
    }
    // ClientState is the AsyncState object.
    internal class ClientState
    {
        private AuthenticatedStream authStream = null;
        private  TcpClient client = null;
        byte[] buffer = new byte[2048];
        StringBuilder message = null;
        ManualResetEvent waiter = new ManualResetEvent(false);
        internal ClientState(AuthenticatedStream a, TcpClient theClient)
        {
            authStream = a;
            client = theClient;
        }
        internal TcpClient Client
        { 
            get { return client;}
        }
        internal AuthenticatedStream AuthenticatedStream
        {
            get { return authStream;}
        }
        internal byte[] Buffer
        {
              get { return buffer;}
        }
        internal StringBuilder Message
        {
            get 
            { 
                if (message == null)
                    message = new StringBuilder();
                return message;
             }
        }
        internal ManualResetEvent Waiter
        {
            get 
            { 
                return waiter;
             }
        }
    }
}