Prompted by a few questions, I thought I’d post about using my Basic and Digest authentication modules with .NET remoting. As you’re probably aware, .NET remoting does not include (out of the box) any built-in authentication mechanism. However, you can leverage IIS to authenticate requests if you wish; Ingo discusses using the IIS implementations of Basic and Integrated Windows authentication in his book. However, as he points out, Basic requires using SSL, and IWA will not work with most typical firewall configurations. Well, as I’ve said in the past, Digest is a good alternative to these two.

I will describe here the necessary code to use the Basic or Digest authentication modules with .NET remoting in IIS. Some code has been omitted for brevity, but all the important parts are here. :-)

Imaging a remote object implementation in RemoteServer.dll, containing the following:

namespace RemoteServer
{
public class Scoop : MarshalByRefObject
{
public Scoop()
{
}

public string GetTheScoop(string name)
{
return “Here’s the scoop, ”
+ Thread.CurrentPrincipal.Identity.Name + “!”;
}
}
}

To host this in IIS, your web.config file might look something like:

<configuration>
<system.runtime.remoting>
<application>
<service>
<wellknown mode=”SingleCall”
type=”RemoteServer.Scoop,RemoteServer”
objectUri=”Scoop.soap” />
</service>
</application>
</system.runtime.remoting>
</configuration>

If you want to use the Digest authentication module, all you need to do is add the required items to this file:

<configuration>
<system.runtime.remoting>
<application>
<service>
<wellknown mode=”SingleCall”
type=”RemoteServer.Scoop,RemoteServer”
objectUri=”Scoop.soap” />
</service>
</application>
</system.runtime.remoting>
<system.web>
<authentication mode=”None” />
<authorization>
<deny users=”?” />
</authorization>
<httpModules>
<add name=”DigestAuthenticationModule”
type=”Rassoc.Samples.DigestAuthenticationModule,DigestAuthMod” />
</httpModules>
</system.web>
<appSettings>
<add key=”Rassoc.Samples.DigestAuthenticationModule_Realm”
value=”RassocDigestSample” />
<add key=”Rassoc.Samples.DigestAuthenticationModule_UserFileVpath”
value=”~/users.xml” />
</appSettings>
</configuration>

And finally, modify the client code which accesses the service to provide credentials:

static void Main(string[] args)
{
ChannelServices.RegisterChannel(new HttpClientChannel());
RemotingConfiguration.RegisterWellKnownClientType(
typeof(RemoteServer.Scoop),
“http://localhost/ScoopRemoting/Scoop.soap“);

Scoop srv = new Scoop();

IDictionary props = ChannelServices.GetChannelSinkProperties(srv);
props[“username”] = “test”;
props[“password”] = “test”;

string s = srv.GetTheScoop(“Greg”);
Console.WriteLine(s);
}

In general, the complete ASP.NET HTTP pipeline is available for your use when hosting remote objects in IIS.