ProtectionLevel Enumeration

Note: This enumeration is new in the .NET Framework version 2.0.

Indicates the security services requested for an authenticated stream.

Namespace: System.Net.Security
Assembly: System (in system.dll)

public enum ProtectionLevel
public enum ProtectionLevel
public enum ProtectionLevel

 Member nameDescription
EncryptAndSignEncrypt and sign data to help ensure the confidentiality and integrity of transmitted data. 
NoneAuthentication only. 
SignSign data to help ensure the integrity of transmitted data. 

This enumeration is used by the NegotiateStream class.

Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition Platform Note: Only None is supported.

The following code example demonstrates creating and using a client-side NegotiateStream.

using System;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Security.Principal;

namespace Examples.NegotiateStreamExample
    public class SynchronousAuthenticatingTcpClient 
        public static void Main(String[] args)  
            // Establish the remote endpoint for the socket.
            // For this example, use the local machine.
            IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            // Client and server use port 11000. 
            IPEndPoint remoteEP = new IPEndPoint(ipAddress,11000);
            // Create a TCP/IP socket.
           TcpClient client = new TcpClient();
            // Connect the socket to the remote endpoint.
            Console.WriteLine("Client connected to {0}.",
            // 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); 
            // Request authentication for the client only (no mutual authentication).
            // Authenicate using the client's default credetials.
            // Permit the server to impersonate the client to access resources on the server only.
            // Request that data be transmitted using encryption and data signing.
                 (NetworkCredential) CredentialCache.DefaultCredentials, 
            if (authStream.CanWrite)
                 // Encode the test data into a byte array.
                byte[] message = System.Text.Encoding.UTF8.GetBytes("Hello from the client.");
                authStream.Write(message, 0, message.Length);
                Console.WriteLine("Sent {0} bytes.", message.Length);
         // Close the client connection.
            Console.WriteLine("Client closed.");
         static void DisplayStreamProperties(NegotiateStream stream)
             Console.WriteLine("Can read: {0}", stream.CanRead);
             Console.WriteLine("Can write: {0}", stream.CanWrite);
             Console.WriteLine("Can seek: {0}", stream.CanSeek);
                 // If the underlying stream supports it, display the length.
                 Console.WriteLine("Length: {0}", stream.Length);
             } catch (NotSupportedException)
                     Console.WriteLine("Cannot get the length of the underlying stream.");
             if (stream.CanTimeout)
                 Console.WriteLine("Read time-out: {0}", stream.ReadTimeout);
                 Console.WriteLine("Write time-out: {0}", stream.WriteTimeout);
         static void DisplayAuthenticationProperties(NegotiateStream 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("ImpersonationLevel: {0}", stream.ImpersonationLevel);
            Console.WriteLine("IsServer: {0}", stream.IsServer);

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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