POST XML using SSL

I need to post XML data to a server and receive an XML response back.
The server that I need to connect to is requires two-way SSL authentication
of the server and client certificates.(I need to have a copy of the server
certificate and my client certificate to present to the server.)

From what I have researched PHP doesn't have any native functions to handle
SSL. One of the possible solutions is using the cURL library. Unfortunate I
am in a shared webhosting environment and they won't install it on the
server.

Does anyone have any information how I can accomplish this?

thanks