Digitally Signing and Encrypting SOAP Messages

Hi,
We have an urgent requirement where in we have to invoke the webServices using SOAP-HTTPS. We have to digitally sign and encrypt the SOAP Request Message using SSL Certificates and then decrypt the SOAP Response.
I am know how to invoke simple webServies using pub.client:soapHTTP, but I donot know how to digitally sign and encrypt the SOAP Request Message using SSL Certificates and then decrypt the SOAP Response.
Any help in this regard is highly appreciated.

Thanks