Securing SoapClient

[RonR]

Hi all,

I'm using the new SOAP extension in PHP5 to create an application. I'm trying to secure this using a ssl certificate, this way Apache will verify whether or not it is a certificate I have issued and the SoapServer will verify whether or not this user is allowed to use the webservice.
At serverside this way of authentication is causing no trouble (Apache's mod_ssl does most of the stuff, the Server only has to check HTTP_SERVER_VARS for user information), however I can't find a way to have SoapClient send a certificate. You can use https with SoapClient, but I can't find a way to use a client certificate... any idead anyone?

Thanks,
Ron