NegotiateStream Klass

Definition

public ref class NegotiateStream : System::Net::Security::AuthenticatedStream

public class NegotiateStream : System.Net.Security.AuthenticatedStream

type NegotiateStream = class
    inherit AuthenticatedStream

Public Class NegotiateStream
Inherits AuthenticatedStream

Arv

Object

MarshalByRefObject

Stream

AuthenticatedStream

NegotiateStream

Exempel

I följande exempel visas klientsidan för en klient-server-anslutning som använder NegotiateStream. Klienten autentiserar och skickar ett meddelande till servern asynkront.

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.
            Task authenticateTask = authStream
                .AuthenticateAsClientAsync()
                .ContinueWith(task =>
                {
                    Console.WriteLine("Client ending authentication...");
                    Console.WriteLine("ImpersonationLevel: {0}", authStream.ImpersonationLevel);
                });

            Console.WriteLine("Client waiting for authentication...");
            // Wait until the result is available.
            authenticateTask.Wait();
            // 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.");
            Task writeTask = authStream
                .WriteAsync(message, 0, message.Length)
                .ContinueWith(task =>
                {
                    Console.WriteLine("Client ending write operation...");
                });

            writeTask.Wait();
            Console.WriteLine("Sent {0} bytes.", message.Length);
            // Close the client connection.
            authStream.Close();
            Console.WriteLine("Client closed.");
        }
    }

    // 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);
        }
    }
}

Imports System.Text
Imports System.Net.Sockets
Imports System.Net.Security
Imports System.Net

Namespace Examples.NegotiateStreamExample

    Public Class ASynchronousAuthenticatingTcpClient

        Shared client As TcpClient = Nothing

        Public Shared Sub Main(args As String())
            ' Establish the remote endpoint for the socket.
            ' For this example, use the local machine.
            Dim ipHostInfo = Dns.GetHostEntry("localhost")
            Dim ipAddress = ipHostInfo.AddressList(0)

            ' Client and server use port 11000. 
            Dim remoteEP As 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.
            Dim clientStream = client.GetStream()
            Dim authStream As New NegotiateStream(clientStream, False)

            ' Pass the NegotiateStream as the AsyncState object 
            ' so that it is available to the callback delegate.
            Dim ar = authStream.BeginAuthenticateAsClient(
                New AsyncCallback(AddressOf 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.
            Dim message = Encoding.UTF8.GetBytes("Hello from the client.")
            ar = authStream.BeginWrite(message, 0, message.Length, 
                New AsyncCallback(AddressOf EndWriteCallback), authStream)
            ar.AsyncWaitHandle.WaitOne()
            Console.WriteLine("Sent {0} bytes.", message.Length)

            ' Close the client connection.
            authStream.Close()
            Console.WriteLine("Client closed.")

        End Sub

        ' The following method is called when the authentication completes.
        Public Shared Sub EndAuthenticateCallback(ar As IAsyncResult)

            Console.WriteLine("Client ending authentication...")
            Dim authStream = CType(ar.AsyncState, NegotiateStream)
            Console.WriteLine("ImpersonationLevel: {0}", authStream.ImpersonationLevel)

            ' End the asynchronous operation.
            authStream.EndAuthenticateAsClient(ar)

        End Sub

        ' The following method is called when the write operation completes.
        Public Shared Sub EndWriteCallback(ar As IAsyncResult)

            Console.WriteLine("Client ending write operation...")
            Dim authStream = CType(ar.AsyncState, NegotiateStream)

            ' End the asynchronous operation.
            authStream.EndWrite(ar)

        End Sub
    End Class

    ' The following class displays the properties of an AuthenticatedStream.
    Public Class AuthenticatedStreamReporter
        Public Shared Sub DisplayProperties(stream As AuthenticatedStream)
            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)
        End Sub
    End Class
End Namespace

I följande kodexempel visas serversidan för en klient-server-anslutning som använder för att autentisera NegotiateStream klienten och läsa ett meddelande som skickas av klienten.

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;
                // 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);
                }
            }
        }

        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.
            Task authTask = authStream
                .AuthenticateAsServerAsync()
                .ContinueWith(task => { EndAuthenticateCallback(cState); });

            // Any exceptions that occurred during authentication are
            // thrown by the EndAuthenticateAsServer method.
            try
            {
                // This call blocks until the authentication is complete.
                authTask.Wait();
            }
            catch (AuthenticationException e)
            {
                Console.WriteLine(e);
                Console.WriteLine("Authentication failed - closing connection.");
                return;
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
                Console.WriteLine("Closing connection.");
                return;
            }

            Task<int> readTask = authStream
                .ReadAsync(cState.Buffer, 0, cState.Buffer.Length);

            readTask
                .ContinueWith((task) => { EndReadCallback(cState, task.Result); })
                .Wait();
            // Finished with the current client.
            authStream.Close();
            clientRequest.Close();
        }

        private static void EndAuthenticateCallback(ClientState cState)
        {
            // Get the saved data.
            NegotiateStream authStream = (NegotiateStream)cState.AuthenticatedStream;
            Console.WriteLine("Ending authentication.");

            // Display properties of the authenticated client.
            IIdentity id = authStream.RemoteIdentity;
            Console.WriteLine("{0} was authenticated using {1}.",
                id.Name,
                id.AuthenticationType
            );
        }

        private static void EndReadCallback(ClientState cState, int bytes)
        {
            NegotiateStream authStream = (NegotiateStream)cState.AuthenticatedStream;
            // Read the client message.
            try
            {
                cState.Message.Append(Encoding.UTF8.GetChars(cState.Buffer, 0, bytes));
                if (bytes != 0)
                {
                    Task<int> readTask = authStream.ReadAsync(cState.Buffer, 0, cState.Buffer.Length);
                    readTask
                        .ContinueWith(task => { EndReadCallback(cState, task.Result); })
                        .Wait();

                    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);
                return;
            }
            IIdentity id = authStream.RemoteIdentity;
            Console.WriteLine("{0} says {1}", id.Name, cState.Message.ToString());
        }
    }
    // ClientState is the AsyncState object.
    internal class ClientState
    {
        private StringBuilder _message = null;

        internal ClientState(AuthenticatedStream a, TcpClient theClient)
        {
            AuthenticatedStream = a;
            Client = theClient;
        }
        internal TcpClient Client { get; }

        internal AuthenticatedStream AuthenticatedStream { get; }

        internal byte[] Buffer { get; } = new byte[2048];

        internal StringBuilder Message
        {
            get { return _message ??= new StringBuilder(); }
        }
    }
}

Kommentarer

NegotiateStream Använd klassen för autentisering och för att skydda information som överförs mellan en klient och en server. Med kan NegotiateStreamdu göra följande.

• Skicka klientens autentiseringsuppgifter till servern för personifiering eller delegering.
• Begär serverautentisering.
• Kryptera och/eller signera data innan du skickar dem.

Autentisering måste utföras innan information överförs. Klienter begär autentisering med hjälp av synkrona AuthenticateAsClient metoder, som blockerar tills autentiseringen har slutförts, eller de asynkrona BeginAuthenticateAsClient metoderna, som inte blockeras i väntan på att autentiseringen ska slutföras. Servrar begär autentisering med hjälp av synkrona AuthenticateAsServer eller asynkrona BeginAuthenticateAsServer metoder. Klienten, och eventuellt servern, autentiseras med hjälp av säkerhetsprotokollet Negotiate. Kerberos-protokollet används för autentisering om både klienten och servern stöder det. annars används NTLM. Klassen NegotiateStream utför autentiseringen med hjälp av SSPI (Security Support Provider Interface).

När autentiseringen IsEncrypted lyckas måste du kontrollera egenskaperna och IsSigned för att avgöra vilka säkerhetstjänster som ska användas av NegotiateStream för att skydda dina data under överföringen. Kontrollera egenskapen IsMutuallyAuthenticated för att avgöra om ömsesidig autentisering har inträffat. Du kan få information om fjärrklienten eller servern med hjälp av RemoteIdentity egenskapen .

Om autentiseringen misslyckas får du en AuthenticationException eller en InvalidCredentialException. I det här fallet kan du försöka autentiseringen igen med en annan autentiseringsuppgift.

Du skickar data med hjälp av synkrona Write eller asynkrona BeginWrite metoder eller WriteAsync metoder. Du får data med hjälp av synkrona Read eller asynkrona ReadAsync eller BeginRead metoder. Om säkerhetstjänster som kryptering eller signering är aktiverade tillämpas dessa automatiskt på dina data av NegotiateStream.

Överför NegotiateStream data med hjälp av en dataström som du anger när du NegotiateStreamskapar . När du anger den underliggande dataströmmen kan du ange om stängningen NegotiateStream även stänger den underliggande strömmen.

Se även

• Ändringar i NTLM-autentisering för HTTPWebRequest i version 3.5 SP1