Implementing ASP.NET web with WIF & ADFS 1.0

Question

I have developed a solution with ASP.NET front-end using WCF-services as back-end. The web-site currently authenticates using ADFS 1.0 (I do not have any control of the ADFS-implementation but it has been configured for my web-application). Also, it's no option to upgrade to ADFS 2.0 (at least not in the near future)

The configuration in Web.config for this is the following:

<httpModules>
   <add name="Identity Federation Services Application Authentication Module" type="System.Web.Security.SingleSignOn.WebSsoAuthenticationModule, System.Web.Security.SingleSignOn, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, Custom=null" />
</httpModules>

<membership defaultProvider="SingleSignOnMembershipProvider2">
            <providers>
                <add name="SingleSignOnMembershipProvider2" type="System.Web.Security.SingleSignOn.SingleSignOnMembershipProvider2, System.Web.Security.SingleSignOn.PartialTrust, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" fs="https://urltoadfs/adfs/fs/FederationServerService.asmx" />
            </providers>
</membership>

<websso>
            <authenticationrequired />
            <urls>
                <returnurl>https://myapplication/</returnurl>
            </urls>
            <fs>https://urltoadfs/adfs/fs/FederationServerService.asmx</fs>
            <isSharePoint />
</websso>

This works fine and i can access the application using an account in ADFS. The problem is that I need to convert this claim-identity to a WindowsIdentity to access the back-end WCF services (they use Windows Authentication with impersonation/delegation).

Is there any way to accomplish this with ADFS 1.0? I have tried to use WIF (Windows Identity Foundation) but I cannot find any clear information if it's possible to use it together with ADFS 1.0 as STS. I have also investigated the "Windows NT token-based applications"-option (http://technet.microsoft.com/en-us/library/cc784956(v=ws.10).aspx) but I would like to avoid changes in the current ADFS-implementation if possible.

To test the WIF-option I used the following configuration in Web.config (the part on websso removed):

<httpModules>           
            <add name="SessionAuthenticationModule" type="Microsoft.IdentityModel.Web.SessionAuthenticationModule, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>        
            <add name="WSFederationAuthenticationModule" type="Microsoft.IdentityModel.Web.WSFederationAuthenticationModule, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
            <add name="ClaimsAuthorizationModule" type="Microsoft.IdentityModel.Web.ClaimsAuthorizationModule, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</httpModules>


<microsoft.identityModel>
    <service>
          <audienceUris>
            <add value="https://myapplication/" />
          </audienceUris>
    <applicationService>
        <claimTypeRequired>        
          <claimType type="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn" optional="true" />
        </claimTypeRequired>
    </applicationService>         
        <securityTokenHandlers> 
          <add type="Microsoft.IdentityModel.Tokens.Saml11.Saml11SecurityTokenHandler, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> 
            <samlSecurityTokenRequirement mapToWindows="true" useWindowsTokenService="true" /> 
          </add> 
        </securityTokenHandlers>
    <federatedAuthentication>
          <wsFederation passiveRedirectEnabled="true"
                        issuer="https://urltoadfs/adfs/fs/FederationServerService.asmx"
                        realm="https://myapplication/"                      
                        requireHttps="true" />
      </federatedAuthentication>        
    </service>    
</microsoft.identityModel>

I also have the "Claims to Windows Token Service" (c2WTS) running on the web-server.

I get redirected to the ADFS-server but I just receives a general error from the server.