Eight steps to enable Windows authentication on WCF BasicHttpBinding

• Download source code - 32.4 KB

Table of contents

• Introduction and goal
• My other WCF FAQ articles
• Step 1: Create a WCF project
• Step 2: Ensure authentication mode is Windows
• Step 3: Define the binding in the web.config file
• Step 4: Bind the bindings with the service interface
• Step 5: Ensure that anonymous access is disabled
• Step 6: Host your WCF service on IIS
• Step 7: Consume the WCF service
• Step 8: Create the WCF client

Introduction and goal

In this session, we will go through eight basic steps by which we can enable Windows authentication security on BasicHttpBinding. There are two types of security you can define in WCF: transport level and message level. In this article, we will discuss how we can define transport level security on BasicHttpBinding.

Nowadays I am distributing my 400 questions and answers ebook which covers major .NET related topics like WCF, WPF, WWF, AJAX, core .NET, SQL Server, architecture, and a lot more. I am sure you will enjoy this ebook: http://www.questpond.com/SampleDotNetInterviewQuestionBook.zip.

My other WCF FAQ articles

• http://www.codeproject.com/KB/aspnet/WCFPart2.aspx to see Windows Communication Framework (WCF) - Part 1
• http://www.codeproject.com/KB/aspnet/WCF.aspx to see Windows Communication Framework (WCF) - Part 2
• WCFTracingFAQ.aspx to see WCF tracing FAQ

Step 1: Create a WCF project

Create a WCF service application project as shown in the below figure:

By default, the WCF project creates a class file which has the GetData function. This function takes in a number values and displays an explanatory sentence like ‘You entered 1 value’ when you enter ‘1’.

public class Service1 : IService1
{
    public string GetData(int value)
    {
        return string.Format("You entered: {0}", value);
    }
}

Step 2: Ensure authentication mode is Windows

When we create a WCF service application, it also has a web.config file associated with it. So open the web.config file and ensure that the authentication mode is Windows.

<authentication mode="Windows" />

Step 3: Define the binding in the web.config file

The third step is to define the bindings and the transport type. To define the bindings, we need to enter the basicHttpBinding element inside the bindings XML tag. We also need to define the clientCredentialType as Windows.

<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpEndpointBinding">
<security mode="TransportCredentialOnly">
<transport clientCredentialType="Windows" />
</security>
</binding>
</basicHttpBinding>
</bindings>
<services>
.........
.........
</system.serviceModel>

Step 4: Bind the bindings with service interface

Now the bindings defined needs to be associated with a service interface, i.e., service1. So we need to modify the services elements as shown below. You can note that we have defined an end point which has the binding association.

<system.serviceModel>
........
........
........
<services>
<service behaviorConfiguration="WCFWindowsBasicHttpBinding.Service1Behavior" 
                       name="WCFWindowsBasicHttpBinding.Service1">
<endpoint address="" binding="basicHttpBinding"
bindingConfiguration="BasicHttpEndpointBinding"
name="BasicHttpEndpoint" contract="WCFWindowsBasicHttpBinding.IService1">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
</service>
</services>
.........
.........
.........
.........
</system.serviceModel>

Overall your <system.serviceModel> XML part as a whole with bindings and services is as shown below:

<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpEndpointBinding">
<security mode="TransportCredentialOnly">
<transport clientCredentialType="Windows" />
</security>
</binding>
</basicHttpBinding>
</bindings>
<services>
<service behaviorConfiguration="WCFWindowsBasicHttpBinding.Service1Behavior" 
               name="WCFWindowsBasicHttpBinding.Service1">
<endpoint address="" binding="basicHttpBinding"
bindingConfiguration="BasicHttpEndpointBinding"
name="BasicHttpEndpoint" contract="WCFWindowsBasicHttpBinding.IService1">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="WCFWindowsBasicHttpBinding.Service1Behavior">
<!-- To avoid disclosing metadata information, set the value below 
               to false and remove the metadata endpoint above before deployment -->
<serviceMetadata httpGetEnabled="true"/>
<!-- To receive exception details in faults for debugging purposes, set the value below 
              to true. Set to false before deployment to avoid disclosing exception information -->
<serviceDebug includeExceptionDetailInFaults="false"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>

Step 5: Ensure that anonymous access is disabled

Go to IIS properties and click on the Security tab and ensure that anonymous access is disabled and only Windows authentication is enabled.

Step 6: Host your WCF service on IIS

We need to host our service in IIS. Make the directory an IIS application so that your service can be hosted. Now if you try to browse the service, i.e., the SVC file, you will see that it pops up the authentication authorization security dialog box. So this service cannot be executed with Windows authentication.

Step 7: Consume the WCF service

Let’s consume the WCF service. Add an ASP.NET web application and do a add web reference. You will be popped up with a dialog box as shown below. Click on Add Reference so that a proxy is generated for the WCF service.

Step 8: Create the WCF client

Type in the following code snippet in your page load. Add the namespace reference and call the method GetData. The most important step to note is the credential supplied. DefaultCredentials passes the current Windows identity to the WCF service.

If you execute the service, you should get the following display as shown below:

You can try commenting the below code in your client, in other words we are not passing any credentials.

obj.Credentials = System.Net.CredentialCache.DefaultCredentials;

Now if you execute, you should get the below error stating that this is an unauthorized call.