Mart Muller's Weblog

I’ve been working with WCF services a lot lately, especially hosted in SharePoint. My Silverlight 2.0 application uses the services to interact with SharePoint, which works great. There are some posts about how to get started with them available, which is great.

the the architecture I’m using for my application, Forms authentication in SharePoint is a must, which means I wrote my own authentication provider. The WCF services however, don’t like that by default and returns a login screen which I can’t pass. Switching from Windows to Forms, break the application.

There is a solution however, to get the WCF services work under forms authentication as well in SharePoint. Note that you must enable cookies (and store the login) to make this solution work. So,

• First we must enable sessions in the SharePoint site. Therefore, enable the session http module in the web.config:

<add name="Session" type="System.Web.SessionState.SessionStateModule"/>

• Second, enable the session state in the pages tag

<pages enableSessionState="true" enableVie…

• Third, where we used Ntml as a clientCredentialType, now the service must use anonymous, so change the type to ‘none’ within your binding and endpoint tag:

<binding name="BasicHttpBinding" maxBufferSize="2147483647" maxReceivedMessageSize="2147483647">
    <security mode="TransportCredentialOnly">
         <transport clientCredentialType="None" />
    </security>
</binding>

and..

<endpoint address="/_layouts/Services/Service.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding" contract="WiZZiX.Services.Service" name="WiZZiX.Services.Service">
    <security mode="Transport">
        <transport clientCredentialType="None" proxyCredentialType="None" realm="" />
        <message clientCredentialType="UserName" algorithmSuite="Default" />
    </security>
</endpoint>

Now, the WCF service works great with forms authentication within the context of SharePoint!

Note that with this configuration, windows authentication doesn’t work anymore, so it’s either windows or forms, not mixed.

With thanks to PaulB for helping me out.