Question

I have a WCF service with a custom IServiceBehavior attached used to return a specific fault on the client side. When I enable this code with TCP Message Security I receive a service timeout.

Below you can see the full client and server code to reproduce the error.

Server code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Channels;

namespace TestWCFServer
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("SERVER");

            NetTcpBinding binding = new NetTcpBinding();
            binding.Security.Mode = SecurityMode.Message; //If you remove this line the code works!!!!

            Uri address = new Uri("net.tcp://localhost:8184/");

            // Create the ServiceHost.
            using (ServiceHost host = new ServiceHost(typeof(HelloWorldService)))
            {
                host.AddServiceEndpoint(typeof(IHelloWorldService), binding, address);

                host.Description.Behaviors.Add(new MyErrorhandlerBehavior());

                host.Open();

                Console.WriteLine("The service is ready at {0}", address);
                Console.WriteLine("Press  to stop the service.");
                Console.ReadLine();

                // Close the ServiceHost.
                host.Close();
            }
        }
    }



    [ServiceContract]
    public interface IHelloWorldService
    {
        [OperationContract]
        string SayHello(string name);
    }

    public class HelloWorldService : IHelloWorldService
    {
        public string SayHello(string name)
        {
            if (name == null)
                throw new ArgumentNullException("name");

            return string.Format("Hello, {0}", name);
        }
    }

    class MyErrorhandlerBehavior : IServiceBehavior, IErrorHandler
    {
        #region IServiceBahvior
        public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection endpoints, BindingParameterCollection bindingParameters)
        {
        }

        public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {
            foreach (ChannelDispatcher chanDisp in serviceHostBase.ChannelDispatchers)
            {
                chanDisp.ErrorHandlers.Add(this);
            }
        }

        public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
        {
        }
        #endregion

        #region IErrorHandler Members
        public bool HandleError(Exception error)
        {
            return true;
        }

        public void ProvideFault(Exception error,MessageVersion ver, ref Message msg)
        {
            FaultException fe = new FaultException(error.Message);
            MessageFault fault = fe.CreateMessageFault();
            msg = Message.CreateMessage(ver, fault, "net.tcp://localhost:8184/fault");
        }
        #endregion
    }
}

Client code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;

namespace TestWCFClient
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("CLIENT");

            try
            {
                NetTcpBinding binding = new NetTcpBinding();
                binding.Security.Mode = SecurityMode.Message; //If you remove this line the code works!!!!

                Uri address = new Uri("net.tcp://localhost:8184/");
                EndpointAddress endpoint = new EndpointAddress(address);

                HelloWorldServiceClient client = new HelloWorldServiceClient(binding, endpoint);

                Console.WriteLine("Calling client with a valid parameter...");
                Console.WriteLine(client.SayHello("Davide"));
                Console.WriteLine("OK");

                Console.WriteLine("Calling client with an invalid parameter...");
                Console.WriteLine(client.SayHello(null)); //This call causes the timeout when Security is set to Message
                Console.WriteLine("OK");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }


            Console.WriteLine("Press enter to exit");
            Console.ReadLine();
        }
    }


    [ServiceContract]
    public interface IHelloWorldService
    {
        [OperationContract]
        string SayHello(string name);
    }

    class HelloWorldServiceClient : System.ServiceModel.ClientBase, IHelloWorldService
    {
        public HelloWorldServiceClient(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress address) :
            base(binding, address)
        { }

        public string SayHello(string name)
        {
            return base.Channel.SayHello(name);
        }
    }
}

If I remove the binding.Security.Mode = SecurityMode.Message; line on the client and on the server the exception is correctly translated and the client can see it without problems.

On the WCF log I see these messages:
No signature message parts were specified for messages with the ‘net.tcp://localhost:8184/fault’ action.
The security protocol cannot secure the outgoing message.

Any idea on how to solve this problem? Seems that I must sign/encrypt the error message but I don’t known how…
If I use Transport security the code works as expected.

thanks!

Answer 1

It might be a bit late to respond but I had the same issue and I figured it out:

You need to define FaultContract on your interface methods along with OperationContract. Have a look here.

Also your fault contract object needs to have the same namespace as the Action namespace.

Sooooooooooo painful but finally figured out and works now.