Securing backend WCF service with WIF using ADFS2 as IP

Eugene S. picture Eugene S. · Jul 6, 2011 · Viewed 8.7k times · Source

I’m having an issue using ADFS2 to secure a back-end WCF service that is being called from Passively Federated Website. I have the passive federation working on the website, but the back-end service is giving me problems.

The pieces of the puzzle.

  1. Silverlight Client that is being served from Passively Federated Website.
  2. The Silverlight calls a WCF service (App Service), hosted on the passively Federated Website.
  3. I have SaveBootstrapToken set to true in the config.
  4. From the App Service, I want to call a back-end WCF service using BootstrapToken with the ActAs scenarion.
  5. Federated Website and Back-end WCF service are setup as separate RPs in the ADFS2, token encryption is turned on. Both are allowed to delegate.

Back-end Service configuration:

I have WIF incorporated into the pipeline using behavior extension.

<ws2007FederationHttpBinding>
  <binding name="WS2007FederationHttpBinding_IQuoteService">
    <security mode="TransportWithMessageCredential">
      <message establishSecurityContext="false">
        <issuer address="https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256">
        </issuer>
        <issuerMetadata address="https://myADFSserver/adfs/services/trust/mex">
        </issuerMetadata>
      </message>
    </security>
  </binding>
</ws2007FederationHttpBinding>


<behaviors>
  <serviceBehaviors>
    <behavior name="">
      <federatedServiceHostConfiguration name="Service.QuoteService" />
      <serviceMetadata httpGetEnabled="true" />
      <serviceDebug includeExceptionDetailInFaults="false" />
      <serviceCredentials>
        <serviceCertificate findValue="000000000000000000000000000000" storeLocation="LocalMachine" storeName="My" x509FindType="FindByThumbprint" />
      </serviceCredentials>
    </behavior>
  </serviceBehaviors>
</behaviors>

<services>
  <service name="Service.QuoteService">
    <endpoint address="" binding="ws2007FederationHttpBinding" contract="Service.IQuoteService" bindingConfiguration="WS2007FederationHttpBinding_IQuoteService" />
    <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
  </service>
</services>

Client Configuration

When add the service using Add Service Reference tooling, the following config on the client gets created:

<customBinding>
  <binding name="https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256">
    <security defaultAlgorithmSuite="Default" authenticationMode="IssuedTokenOverTransport"
      requireDerivedKeys="false" securityHeaderLayout="Strict" includeTimestamp="true"
      keyEntropyMode="CombinedEntropy" messageSecurityVersion="WSSecurity11WSTrust13WSSecureConversation13WSSecurityPolicy12BasicSecurityProfile10">
      <issuedTokenParameters keySize="256" keyType="SymmetricKey" tokenType="">
        <additionalRequestParameters>
          <trust:SecondaryParameters xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">
            <trust:KeyType>http://docs.oasis-open.org/ws-sx/ws-trust/200512/SymmetricKey</trust:KeyType>
            <trust:KeySize>256</trust:KeySize>
            <trust:KeyWrapAlgorithm>http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p</trust:KeyWrapAlgorithm>
            <trust:EncryptWith>http://www.w3.org/2001/04/xmlenc#aes256-cbc</trust:EncryptWith>
            <trust:SignatureAlgorithm>http://www.w3.org/2000/09/xmldsig#hmac-sha1</trust:SignatureAlgorithm>
            <trust:CanonicalizationAlgorithm>http://www.w3.org/2001/10/xml-exc-c14n#</trust:CanonicalizationAlgorithm>
            <trust:EncryptionAlgorithm>http://www.w3.org/2001/04/xmlenc#aes256-cbc</trust:EncryptionAlgorithm>
          </trust:SecondaryParameters>
        </additionalRequestParameters>
      </issuedTokenParameters>
      <localClientSettings cacheCookies="true" detectReplays="false"
        replayCacheSize="900000" maxClockSkew="00:05:00" maxCookieCachingTime="Infinite"
        replayWindow="00:05:00" sessionKeyRenewalInterval="10:00:00"
        sessionKeyRolloverInterval="00:05:00" reconnectTransportOnFailure="true"
        timestampValidityDuration="00:05:00" cookieRenewalThresholdPercentage="60" />
      <localServiceSettings detectReplays="false" issuedCookieLifetime="10:00:00"
        maxStatefulNegotiations="128" replayCacheSize="900000" maxClockSkew="00:05:00"
        negotiationTimeout="00:01:00" replayWindow="00:05:00" inactivityTimeout="00:02:00"
        sessionKeyRenewalInterval="15:00:00" sessionKeyRolloverInterval="00:05:00"
        reconnectTransportOnFailure="true" maxPendingSessions="128"
        maxCachedCookies="1000" timestampValidityDuration="00:05:00" />
      <secureConversationBootstrap />
    </security>
    <textMessageEncoding maxReadPoolSize="64" maxWritePoolSize="16"
      messageVersion="Default" writeEncoding="utf-8">
      <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
    </textMessageEncoding>
    <httpsTransport manualAddressing="false" maxBufferPoolSize="524288"
      maxReceivedMessageSize="65536" allowCookies="false" authenticationScheme="Anonymous"
      bypassProxyOnLocal="false" decompressionEnabled="true" hostNameComparisonMode="StrongWildcard"
      keepAliveEnabled="true" maxBufferSize="65536" proxyAuthenticationScheme="Anonymous"
      realm="" transferMode="Buffered" unsafeConnectionNtlmAuthentication="false"
      useDefaultWebProxy="true" requireClientCertificate="false" />
  </binding>
</customBinding>


<ws2007FederationHttpBinding>
  <binding name="WS2007FederationHttpBinding_IQuoteService" closeTimeout="00:01:00"
    openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
    bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
    maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text"
    textEncoding="utf-8" useDefaultWebProxy="true">
    <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
      maxBytesPerRead="4096" maxNameTableCharCount="16384" />
    <reliableSession ordered="true" inactivityTimeout="00:10:00"
      enabled="false" />
    <security mode="Message">
      <message algorithmSuite="Default" issuedKeyType="SymmetricKey"
        negotiateServiceCredential="true">
        <issuer address="https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256"
          binding="customBinding" bindingConfiguration="https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256" />
        <issuerMetadata address="https://myADFSserver/adfs/services/trust/mex" />
        <tokenRequestParameters>
          <trust:SecondaryParameters xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">
            <trust:KeyType xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://docs.oasis-open.org/ws-sx/ws-trust/200512/SymmetricKey</trust:KeyType>
            <trust:KeySize xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">256</trust:KeySize>
            <trust:Claims Dialect="http://schemas.xmlsoap.org/ws/2005/05/identity"
              xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">
              <wsid:ClaimType Uri="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name"
                Optional="true" xmlns:wsid="http://schemas.xmlsoap.org/ws/2005/05/identity" />
              <wsid:ClaimType Uri="http://schemas.microsoft.com/ws/2008/06/identity/claims/role"
                Optional="true" xmlns:wsid="http://schemas.xmlsoap.org/ws/2005/05/identity" />
            </trust:Claims>
            <trust:KeyWrapAlgorithm xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p</trust:KeyWrapAlgorithm>
            <trust:EncryptWith xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://www.w3.org/2001/04/xmlenc#aes256-cbc</trust:EncryptWith>
            <trust:SignWith xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://www.w3.org/2000/09/xmldsig#hmac-sha1</trust:SignWith>
            <trust:CanonicalizationAlgorithm xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://www.w3.org/2001/10/xml-exc-c14n#</trust:CanonicalizationAlgorithm>
            <trust:EncryptionAlgorithm xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">http://www.w3.org/2001/04/xmlenc#aes256-cbc</trust:EncryptionAlgorithm>
          </trust:SecondaryParameters>
        </tokenRequestParameters>
      </message>
    </security>
  </binding>
</ws2007FederationHttpBinding>


<client>
  <endpoint address="http://myServiceHost/Service/QuoteService.svc"
    binding="ws2007FederationHttpBinding" bindingConfiguration="WS2007FederationHttpBinding_IQuoteService"
    contract="QuoteService.IQuoteService" name="WS2007FederationHttpBinding_IQuoteService">
    <identity>
      <certificate encodedValue="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" />
    </identity>
  </endpoint>
</client>

Here's the Service Client Code:

List<Quote> quoteList = new List<Quote>();

ClaimsPrincipal myClaimsPrincipal = System.Web.HttpContext.Current.User as ClaimsPrincipal;
SecurityToken bootstrapToken = myClaimsPrincipal.Identities[0].BootstrapToken;
if (bootstrapToken == null)
{
    throw new Exception("bootstrap tokein is null. Logout and try again.");
}

ChannelFactory<IQuoteServiceChannel> factory = new ChannelFactory<IQuoteServiceChannel>("WS2007FederationHttpBinding_IQuoteService");
factory.Credentials.SupportInteractive = false;

factory.Credentials.ServiceCertificate.SetDefaultCertificate(StoreLocation.LocalMachine, StoreName.My, X509FindType.FindByThumbprint, "0000000000000000000000000000");
factory.ConfigureChannelFactory();

IQuoteServiceChannel channel;

//Create the channel with the bootstrap token
channel = factory.CreateChannelActingAs(bootstrapToken);

try
{
    quoteList = channel.GetQuotes(quoteUser);
    channel.Close();
}
catch (SecurityAccessDeniedException sadex)
{
    channel.Abort();
    throw;
}
catch (CommunicationException exception)
{
    channel.Abort();
    throw;
}
catch (TimeoutException timeoutEx)
{
    channel.Abort();
    throw;
}
catch (Exception ex)
{
    channel.Abort();
    throw;
}

return quoteList;

This is the exception I get:

System.ServiceModel.Security.SecurityNegotiationException was unhandled by user code
  Message=SOAP security negotiation with 'https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256' for target 'https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256' failed. See inner exception for more details.
  Source=mscorlib
  StackTrace:
    Server stack trace: 
       at System.ServiceModel.Security.IssuanceTokenProviderBase`1.DoNegotiation(TimeSpan timeout)
       at System.ServiceModel.Security.IssuanceTokenProviderBase`1.GetTokenCore(TimeSpan timeout)
       at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout)
       at Microsoft.IdentityModel.Protocols.WSTrust.FederatedSecurityTokenProvider.GetTokenCore(TimeSpan timeout)
       at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout)
       at System.ServiceModel.Security.SecurityProtocol.TryGetSupportingTokens(SecurityProtocolFactory factory, EndpointAddress target, Uri via, Message message, TimeSpan timeout, Boolean isBlockingCall, IList`1& supportingTokens)
       at System.ServiceModel.Security.SymmetricSecurityProtocol.TryGetTokenSynchronouslyForOutgoingSecurity(Message message, SecurityProtocolCorrelationState correlationState, Boolean isBlockingCall, TimeSpan timeout, SecurityToken& token, SecurityTokenParameters& tokenParameters, SecurityToken& prerequisiteWrappingToken, IList`1& supportingTokens, SecurityProtocolCorrelationState& newCorrelationState)
       at System.ServiceModel.Security.SymmetricSecurityProtocol.SecureOutgoingMessageCore(Message& message, TimeSpan timeout, SecurityProtocolCorrelationState correlationState)
       at System.ServiceModel.Security.MessageSecurityProtocol.SecureOutgoingMessage(Message& message, TimeSpan timeout, SecurityProtocolCorrelationState correlationState)
       at System.ServiceModel.Channels.SecurityChannelFactory`1.SecurityRequestChannel.Request(Message message, TimeSpan timeout)
       at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.DoOperation(SecuritySessionOperation operation, EndpointAddress target, Uri via, SecurityToken currentToken, TimeSpan timeout)
       at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.GetTokenCore(TimeSpan timeout)
       at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout)
       at System.ServiceModel.Security.SecuritySessionClientSettings`1.ClientSecuritySessionChannel.OnOpen(TimeSpan timeout)
       at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
       at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
       at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
       at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout)
       at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
       at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
       at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
       at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
    Exception rethrown at [0]: 
       at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
       at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
       at OMG.Admin.DemoApp.Business.QuoteService.IQuoteService.GetQuotes(User quoteUser)
       at OMG.Admin.DemoApp.Business.QuoteServiceClient.GetQuotes(User quoteUser) in C:\OMG_TFS01\OMG.Admin\OMG.Admin.DemoApp\OMG.Admin.DemoApp.Business\QuoteServiceClient.cs:line 131
       at OMG.Admin.DemoApp.Business.QuoteBO.GetQuoteList() in C:\OMG_TFS01\OMG.Admin\OMG.Admin.DemoApp\OMG.Admin.DemoApp.Business\QuoteBO.cs:line 26
       at OMG.Admin.DemoApp.Web.Services.DemoAppService.GetQuotes() in C:\OMG_TFS01\OMG.Admin\OMG.Admin.DemoApp\OMG.Admin.DemoApp.Web\Services\DemoAppService.svc.cs:line 27
       at SyncInvokeGetQuotes(Object , Object[] , Object[] )
       at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
       at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
  InnerException: System.InvalidOperationException
       Message=The address of the security token issuer is not specified. An explicit issuer address must be specified in the binding for target 'https://myADFSserver/adfs/services/trust/13/issuedtokenmixedsymmetricbasic256' or the local issuer address must be configured in the credentials.
       Source=mscorlib
       StackTrace:
         Server stack trace: 
            at System.ServiceModel.ClientCredentialsSecurityTokenManager.CreateIssuedSecurityTokenProvider(InitiatorServiceModelSecurityTokenRequirement initiatorRequirement)
            at System.ServiceModel.ClientCredentialsSecurityTokenManager.CreateSecurityTokenProvider(SecurityTokenRequirement tokenRequirement, Boolean disableInfoCard)
            at Microsoft.IdentityModel.Protocols.WSTrust.FederatedClientCredentialsSecurityTokenManager.CreateSecurityTokenProvider(SecurityTokenRequirement tokenRequirement)
            at System.ServiceModel.Security.SecurityProtocol.AddSupportingTokenProviders(SupportingTokenParameters supportingTokenParameters, Boolean isOptional, IList`1 providerSpecList)
            at System.ServiceModel.Security.SecurityProtocol.OnOpen(TimeSpan timeout)
            at System.ServiceModel.Security.WrapperSecurityCommunicationObject.OnOpen(TimeSpan timeout)
            at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
            at System.ServiceModel.Channels.SecurityChannelFactory`1.ClientSecurityChannel`1.OnOpen(TimeSpan timeout)
            at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
            at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
            at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
         Exception rethrown at [0]: 
            at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
            at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
            at System.ServiceModel.ICommunicationObject.Open(TimeSpan timeout)
            at System.ServiceModel.Security.IssuanceTokenProviderBase`1.DoNegotiation(TimeSpan timeout)
       InnerException:

I'm sure I'm missing something in the configuration and/or code can someone help me out?

Answer

Eugene S. picture Eugene S. · Jul 15, 2011

I got this scenario working, here’s the solution for anyone interested.

Followed Dominick Baier’s post for ideas / code: http://leastprivilege.com/2010/10/14/wif-adfs-2-and-wcfpart-5-service-client-more-flexibility-with-wstrustchannelfactory/

I changed the back-end WCF service config to this:

<microsoft.identityModel>
  <service>
    <audienceUris>
      <add value="https://localhost/Service/QuoteService.svc" />
      <add value="https://localhost/Service/" />
    </audienceUris>
    <serviceCertificate>
      <certificateReference x509FindType="FindByThumbprint" findValue="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" />
    </serviceCertificate>
    <issuerNameRegistry type="Microsoft.IdentityModel.Tokens.ConfigurationBasedIssuerNameRegistry, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
      <trustedIssuers>
        <add thumbprint="000000000000000000000000000000000000" name="http://myADFSserver/adfs/services/trust" />
      </trustedIssuers>
    </issuerNameRegistry>
    <certificateValidation certificateValidationMode="None" />
  </service>
</microsoft.identityModel>

<system.serviceModel>
  <services>
    <service name="Service.QuoteService">
      <endpoint address=""
                binding="ws2007FederationHttpBinding"
                contract="Service.IQuoteService" />
      <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
    </service>
  </services>
  <bindings>
    <ws2007FederationHttpBinding>
      <binding>
        <security mode="TransportWithMessageCredential">
          <message establishSecurityContext="false">
            <issuerMetadata address="https://myADFSserver/adfs/services/trust/mex" />
          </message>
        </security>
      </binding>
    </ws2007FederationHttpBinding>
  </bindings>

  <behaviors>
    <serviceBehaviors>
      <behavior>
        <serviceMetadata httpsGetEnabled="true" />
        <federatedServiceHostConfiguration />
      </behavior>
    </serviceBehaviors>
  </behaviors>

  <extensions>
    <behaviorExtensions>
      <add name="federatedServiceHostConfiguration"
           type="Microsoft.IdentityModel.Configuration.ConfigureServiceHostBehaviorExtensionElement, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </behaviorExtensions>
  </extensions>
</system.serviceModel>

I’m no longer using WCF config on the client, it’s all done in code.

Here’s the client code:

public QuoteServiceClient()
{
    SecurityToken actAsToken = this.GetDelegatedTokenUsername();
    var binding = new WS2007FederationHttpBinding(WSFederationHttpSecurityMode.TransportWithMessageCredential);
    binding.Security.Message.EstablishSecurityContext = false;

    ChannelFactory<IQuoteServiceChannel> factory = 
                    new ChannelFactory<IQuoteServiceChannel>(binding, new EndpointAddress(svcEndpoint));
    factory.ConfigureChannelFactory<IQuoteServiceChannel>();
    factory.Credentials.SupportInteractive = false;

    this.channel = factory.CreateChannelWithIssuedToken<IQuoteServiceChannel>(actAsToken);
}

private SecurityToken GetDelegatedTokenUsername()
{
    var binding = new UserNameWSTrustBinding();
    binding.SecurityMode = SecurityMode.TransportWithMessageCredential;

    //UserNameMixed is this endpoint "/adfs/services/trust/13/usernamemixed"
    WSTrustChannelFactory trustChannelFactory = new WSTrustChannelFactory(binding, new EndpointAddress(UserNameMixed));
    trustChannelFactory.TrustVersion = System.ServiceModel.Security.TrustVersion.WSTrust13;

    trustChannelFactory.Credentials.SupportInteractive = false;
    //Some User Account
    //It's used to access the ADFS Server
    //Act as is the actual Identity that Will be used.
    //If you use one of windows bindings (ex. windowstransport), you wont need this.
    //The AppPool identity will be used then.
    trustChannelFactory.Credentials.UserName.UserName = @"domain\username";
    trustChannelFactory.Credentials.UserName.Password = "password";

    try
    {
        RequestSecurityToken rst = new RequestSecurityToken();
        rst.RequestType = WSTrust13Constants.RequestTypes.Issue;
        rst.AppliesTo = new EndpointAddress(ServiceAppliesTo);

        //This part will give you identity of logged in user
        rst.ActAs = new SecurityTokenElement(this.GetBootStrapToken());

        var channel = trustChannelFactory.CreateChannel();
        RequestSecurityTokenResponse rstr = null;
        SecurityToken delegatedToken = channel.Issue(rst, out rstr);

        return delegatedToken;
    }
    catch (Exception ex)
    {
        throw new Exception(ex.Message, ex);
    }
    finally
    {
        try
        {
            if (trustChannelFactory.State == CommunicationState.Faulted)
            {
                trustChannelFactory.Abort();
            }
            else
            {
                trustChannelFactory.Close();
            }
        }
        catch (Exception)
        { }
    }
}

private SecurityToken GetBootStrapToken()
{
    ClaimsPrincipal myClaimsPrincipal = System.Web.HttpContext.Current.User as ClaimsPrincipal;
    SecurityToken bootstrapToken = myClaimsPrincipal.Identities[0].BootstrapToken;

    if (bootstrapToken == null)
    {
        throw new Exception("bootstrap tokein is null. Logout and try again.");
    }
    return bootstrapToken;
}

That is all good and dandy, except you will not have proper claims on the back-end WCF service. Using this great article I was able to sort out the claim stuff in ADFS: http://technet.microsoft.com/en-us/library/adfs2-identity-delegation-step-by-step-guide.aspx . Scroll down to Enabling Identity Delegation and Fixing Claims Issuance Rules at CONTOSODC. I also removed claim encryption from Passively Federated Website.

After doing this I have same claims in the app service and the back-end WCF service.

I hope this helps someone in the same boat as I was.