How To: Enable WIF for a WCF Web Service Application

Article
03/30/2017

Applies To

Microsoft® Windows® Identity Foundation (WIF)
Microsoft® Windows® Communication Foundation (WCF)

Summary

This How-To provides detailed step-by-step procedures for enabling WIF in a WCF web service. It also provides instructions for how to test the application to verify that the web service is correctly presenting claims when the application is run. This How-To does not have detailed instructions for creating a Security Token Service (STS), and instead uses the Development STS that comes with the Identity and Access tool. The Development STS does not perform real authentication and is intended for testing purposes only. You will need to install the Identity and Access tool to complete this How-To. It can be downloaded from the following location: Identity and Access Tool

Objectives
Overview
Summary of Steps
Step 1 – Create a Simple WCF Service
Step 2 – Create a Client Application for the WCF Service
Step 3 – Test Your Solution

Objectives

Create a WCF service that requires issued tokens
Create a WCF client that requests a token from an STS and passes it to the WCF service

Overview

This How-To is intended to demonstrate how a developer can use federated authentication when developing WCF services. Some of the benefits of using federation in WCF services include:

Factoring authentication logic out of WCF service code
Re-using existing identity management solutions
Interoperability with other identity solutions
Flexibility and resilience to future changes

WIF and the associated Identity and Access tool make it easier to develop and test a WCF service using federated authentication, as the following steps demonstrate.

Summary of Steps

Step 1 – Create a Simple WCF Service
Step 2 – Create a Client Application for the WCF Service
Step 3 – Test Your Solution

Step 1 – Create a Simple WCF Service

In this step, you will create a new WCF service that uses the Development STS that is included with the Identity and Access tool.

To create a simple WCF service

Start Visual Studio in elevated mode as administrator.
In Visual Studio, click File, click New, and then click Project.
In the New Project window, click WCF Service Application.
In Name, enter TestService and press OK.
Right-click the TestService project under Solution Explorer, then select Identity and Access.
The Identity and Access window appears. Under Providers, select Test your application with the Local Development STS, then click Apply. The Identity and Access Tool configures the service to use WIF and to outsource authentication to the local development STS (LocalSTS) by adding configuration elements to the Web.config file.

In the Service1.svc.cs file, add a using directive for the System.Security.Claims namespace and replace the existing code with the following, then save the file:

public class Service1 : IService1
{
    public string ComputeResponse(string input)
    {
        // Get the caller's identity from ClaimsPrincipal.Current
        ClaimsPrincipal claimsPrincipal = OperationContext.Current.ClaimsPrincipal;

        // Start generating the output
        StringBuilder builder = new StringBuilder();
        builder.AppendLine("Computed by ClaimsAwareWebService");
        builder.AppendLine("Input received from client:" + input);

        if (claimsPrincipal != null)
        {
            // Display the claims from the caller. Do not use this code in a production application.
            ClaimsIdentity identity = claimsPrincipal.Identity as ClaimsIdentity;
            builder.AppendLine("Client Name:" + identity.Name);
            builder.AppendLine("IsAuthenticated:" + identity.IsAuthenticated);
            builder.AppendLine("The service received the following issued claims of the client:");

            // Iterate over the caller’s claims and append to the output
            foreach (Claim claim in claimsPrincipal.Claims)
            {
                builder.AppendLine("ClaimType :" + claim.Type + "   ClaimValue:" + claim.Value);
            }
        }

        return builder.ToString();
    }
}

The ComputeResponse method displays the properties of various claims that are issued by LocalSTS.

In the IService1.cs file, replace the existing code with the following, then save the file:

[ServiceContract]
public interface IService1
{
    [OperationContract]
    string ComputeResponse(string input);
}

Build the project.
Press Ctrl-F5 to run the service without starting the debugger. A Web page should open for the service and you can verify that LocalSTS is running by looking in the notification area (system tray).

Important

Both TestService and LocalSTS must be running when you add the service reference to the client application in the next step.

Step 2 – Create a Client Application for the WCF Service

In this step, you will create a console application that uses the Development STS to authenticate with the WCF service you created in the previous step.

To create a client application

In Visual Studio, right-click on the solution, click Add, and then click New Project.
In the Add New Project window, select Console Application from the Visual C# templates list, enter Client, and then press OK. The new project will be created in your solution folder.
Right-click on References under the Client project, and then click Add Service Reference.
In the Add Service Reference window, click the drop-down arrow on the Discover button and click Services in Solution. The Address will automatically populate with the WCF service you created earlier, and the Namespace will be set to ServiceReference1. Click OK.

Important

Both TestService and LocalSTS must be running when you add the service reference to the client.

Visual Studio will generate proxy classes for the WCF service, and add all of the necessary reference information. It will also add elements to the App.config file to configure the client to get a token from the STS to authenticate with the service. When this process is finished, the Program.cs file will open. Add a using directive for System.ServiceModel and another for Client.ServiceReference1, replace the Main method with the following code, then save the file:

static void Main(string[] args)
{
    // Create the client for the service
    Service1Client client = new Service1Client();
    Console.WriteLine("-------------WCF Client Application--------------\n");

    while (!ShouldQuitApplication())
    {
        try
        {
            Console.WriteLine(client.ComputeResponse("Hello World"));
        }
        catch (CommunicationException e)
        {
            Console.WriteLine(e.Message);
            Console.WriteLine(e.StackTrace);
            Exception ex = e.InnerException;
            while (ex != null)
            {
                Console.WriteLine("===========================");
                Console.WriteLine(ex.Message);
                Console.WriteLine(ex.StackTrace);
                ex = ex.InnerException;
            }
        }
        catch (TimeoutException)
        {
            Console.WriteLine("Timed out...");
        }
        catch (Exception e)
        {
            Console.WriteLine("An unexpected exception occurred.");
            Console.WriteLine(e.StackTrace);
        }
    }

    client.Close();

    if (client != null)
    {
        client.Abort();
    }
}

static bool ShouldQuitApplication()
{
    Console.WriteLine("---------------------------------------------------------------------");
    Console.WriteLine("Press Enter key to invoke service, any other key to quit application:");
    Console.WriteLine("----------------------------------------------------------------------");

    ConsoleKeyInfo keyInfo = Console.ReadKey();
    if (keyInfo.Key == ConsoleKey.Enter)
        return false;
    return true;
}

Open the App.config file and add the following XML as the first child element under the <system.serviceModel> element, then save the file:

<behaviors>
   <endpointBehaviors>
     <behavior>
       <clientCredentials>
         <serviceCertificate>
           <authentication certificateValidationMode="None"/>
         </serviceCertificate>
       </clientCredentials>
     </behavior>
   </endpointBehaviors>
 </behaviors>

This disables certificate validation.

Right-click the TestService solution and click on Set StartUp Projects. The Startup Project property page opens. In the Startup Project property page, select Multiple startup projects then click in the Action field for each project and select Start from the drop-down menu. Click OK to save the settings.
Build the solution.

Step 3 – Test Your Solution

In this step you will test your WIF-enabled WCF application and verify that claims are presented.

To test your WIF-enabled WCF application for claims

Press F5 to build and run the application. You should be presented with a console window, and the following text: Press Enter key to invoke service, any other key to quit application:

Press Enter, and the following claims information should appear in the console:

Computed by Service1
Input received from client: Hello World
Client Name: Terry
IsAuthenticated: True
The service received the following issued claims of the client:
ClaimType :https://schemas.xmlsoap.org/ws/2005/05/identity/claims/name    ClaimValue:Terry
ClaimType :http://schema.xmlsoap.org/ws/2005/05/identity/claims/surname    ClaimValue:Adams
ClaimType :https://schemas.microsoft.com/ws/2008/06/identity/claims/role    ClaimValue:developer
ClaimType :https://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress    ClaimValue:terry@contoso.com

Important

Both TestService and LocalSTS must be running before you press Enter. A Web page should open for the service and you can verify that LocalSTS is running by looking in the notification area (system tray).

If these claims appear in the console, you have successfully authenticated with the STS to display claims from the WCF service.

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