Configure SamlCallbackHandler for Dispatch client

[Burkard Stephan]

Hi 

I am trying to "decorate" an outgoing web service call with a SAML token for 
authentication. Therefore I have written a SamlCallbackHandler. It is for sure 
not yet complete, but I am already failing to configure it onto my CXF client 
which is a Dispatch client.

I have found that I need to configure the key 
SecurityConstants.SAML_CALLBACK_HANDLER with my SamlCallbackHandler instance. 

I also found JAX-B based examples who configure the handler on the web service 
port type: 
    ((BindingProvider)saml2Port).getRequestContext().put(
    "ws-security.saml-callback-handler", new SamlCallbackHandler()
    );

But my dispatch client has no port type class. It looks like this (simplified 
names):

    @Bean
    public Dispatch<Source> myClient(final SamlCallbackHandler 
samlCallbackHandler) {
        QName serviceName = new QName("namespace", "service");
        QName portName = new QName("namespace ", "port");
        Service service = Service.create(serviceName);
        service.addPort(portName, SOAPBinding.SOAP11HTTP_BINDING, "address");
        Dispatch<Source> dispatch = service.createDispatch(portName, 
Source.class, Service.Mode.PAYLOAD);
        Client client = 
((org.apache.cxf.jaxws.DispatchImpl)dispatch).getClient();
        client.getInInterceptors().add(new LoggingInInterceptor());
        client.getOutInterceptors().add(new LoggingOutInterceptor());
        return dispatch;
    }

On this client I tried to configure my SamlCallbackHandler like this: 

    1. client.getRequestContext().put(SecurityConstants.SAML_CALLBACK_HANDLER, 
samlCallbackHandler);
    2. client.getEndpoint().put(SecurityConstants.SAML_CALLBACK_HANDLER, 
samlCallbackHandler);

Unfortunately none of them works, the handle method of the handler is never 
called and therefore the outgoing request has no token. 

How can I configure the SamlCallbackHandler on a Dispatch client? I did not 
found an example in the CXF project. 

Thanks
Stephan