Secure XKMS request and XKMS response

Hi All,

I need to know how I can digitally sign the XKMS request and response. I couldn't find a sample in the online XKMS spec which could guide me. Does XKMS provides a built in feature i.e. we can create the signature of the XKMS request and then place it with in the XKMS request and similarly with the XKMS response (Similar to the way a signature gets embedded in a digital Certificate)OR we need to create the XKMS request and then place it inside a XMLDSig object and then send it to the server and similarly with the XKMS Response. 

Also is there any website where I can get a complete list of sample XKMS request/responses to get a better understanding.

Thanks for reading...

Regards,
Andy