[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!!!!