[SOAP] authentication issue

I am trying to connect to a .net service using PHP soap extensions but having problems connecting to their service which requires authentication and is over ssl. I'm passing the login name and password through the soapClient method but am still receiving "unauthorized" message back. Is this because a pem file needs to be generated and referred to in order to establish a connection to the server over ssl? If so, how do I generate a pem file? Thanks in advance!!!!