Remoting Example: Hosting in Internet Information Services (IIS)

The following sample implements a basic Web service with a few complications. The BinaryFormatter is used because the payload is more compact and the system takes less time to serialize and deserialize the stream. In addition, if Internet Information Services (IIS) is using Windows Integrated Authentication (also known as NTLM authentication), the server authenticates the client, and then returns to the client the identity that IIS was able to authenticate. Finally, you can help protect your Web service by changing the URL in the client configuration file to use "https" as the protocol scheme and configuring IIS to require Secure Sockets Layer (SSL) encryption for that virtual directory (the sample does not demonstrate this process).

CAUTION   .NET remoting does not do authentication or encryption by default. Therefore, it is recommended that you take all necessary steps to make certain of the identity of clients or servers before interacting with them remotely. Because .NET remoting applications require FullTrust permissions to execute, if a unauthorized client were granted access on your server, the client could execute code as though it were fully trusted. Always authenticate your endpoints and encrypt the communication streams, either by hosting your remoted types in IIS or by building a custom channel sink pair to do this work.

To compile and run this sample

1. Save all the files in a directory named RemoteIIS.

2. Compile the entire sample by typing the following commands at the command prompt:

   csc /noconfig /t:library /r:System.Web.dll /out:ServiceClass.dll ServiceClass.cs

   csc /noconfig /r:System.Runtime.Remoting.dll /r:System.dll /r:ServiceClass.dll Client.cs

3. Create a \bin subdirectory and copy ServiceClass.dll into that directory.

4. Create a virtual directory in IIS. Make the virtual directory alias "HttpBinary" and set the source directory to the "RemoteIIS" directory.

5. Set the authentication method for this virtual directory to Integrated Windows Authentication (formerly NTLM authentication).

6. Make sure that IIS is started; at the command prompt in the "RemoteIIS" directory, type client.

This application runs on a single computer or across a network. If you want to run this application over a network, you must replace "localhost" in the client configuration with the name of the remote computer.

ServiceClass.cs

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Threading;
using System.Web;

public interface IService{

   DateTime GetServerTime();
   string GetServerString();

}

// IService exists to demonstrate the possibility of publishing only the interface.
public class ServiceClass : MarshalByRefObject, IService{

   private int InstanceHash;

   public ServiceClass(){
      InstanceHash = this.GetHashCode();
   }

   public DateTime GetServerTime(){
      return DateTime.Now;
   }

   public string GetServerString(){
      // Use the HttpContext to acquire what IIS thinks the client's identity is.
      string temp = HttpContext.Current.User.Identity.Name;
      if (temp == null || temp.Equals(string.Empty))
         temp = "**unavailable**";
      return "Hi there. You are being served by instance number: " 
         + InstanceHash.ToString() 
         + ". Your alias is: " 
         + temp;
   }
}

Web.config

<configuration>
   <system.runtime.remoting>
      <application>
         <service>
            <wellknown 
               mode="SingleCall" objectUri="SAService.rem"
               type="ServiceClass, ServiceClass"/>
         </service>
         <channels>
            <channel ref="http"/>
         </channels>
      </application>
   </system.runtime.remoting>
</configuration>

Client.cs

using System;
using System.Collections;
using System.Diagnostics;
using System.Net;
using System.Reflection;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Security.Principal;

public class Client{

   public static void Main(string[] Args){

         // Tells the system about the remote object and customizes the HttpChannel
         // to use the binary formatter (which understands that base64 encoding is needed).
         RemotingConfiguration.Configure("Client.exe.config");

         // New proxy for the ServiceClass.
         // If you publish only the IService interface, you must use Activator.GetObject.
         ServiceClass service = new ServiceClass(); 
            
         // Programmatically customizes the properties given to the channel. This sample uses the
         // application configuration file.
         // IDictionary Props = ChannelServices.GetChannelSinkProperties(service);
         // Props["credentials"] = CredentialCache.DefaultCredentials;

         // Reports the client identity name.
         Console.WriteLine("ConsoleIdentity: " + WindowsIdentity.GetCurrent().Name);

         // Writes what the server returned.
         Console.WriteLine("The server says : " + service.GetServerString());
         Console.WriteLine("Server time is: " + service.GetServerTime());      
   }
}

Client.exe.config

<configuration>
   <system.runtime.remoting>
      <application>
         <channels>
            <channel ref="http" useDefaultCredentials="true" port="0">
               <clientProviders>
                  <formatter 
                     ref="binary"
                  />
               </clientProviders>
            </channel>
         </channels>
         <client>
            <wellknown 
               url="https://localhost:80/HttpBinary/SAService.rem"
               type="ServiceClass, ServiceClass"
            />
         </client>
      </application>
   </system.runtime.remoting>
</configuration>

See Also

Remoting Examples | Configuration | Hosting Remote Objects in Internet Information Services (IIS)