Extending php SoapClient for siteminder authentication

Short Version

I want to extend SoapClient so it does this internally when accessing the WSDL:

curl -L -E /location/of/cert.pem -c /tmp/location/of/cookie.jar https://web-service-provider/servicename?wsdl

Long Version

I've got a SOAP request similar to this:

$serviceUrl = 'https://service-url';
$wsdl = $serviceUrl . '?wsdl';

$proxyServiceUrl = 'http://localhost/myproxy.php?url=$serviceUrl';
$proxyWsdl = 'http://localhost/myproxy.php?url=$wsdl';

$options = array(
  'cache_wsdl'    => WSDL_CACHE_NONE,
  'encoding'      => 'utf-8',
  'soap_version'  => SOAP_1_1,
  'exceptions'    => true,
  'trace'         => true,
  'location'      => $proxyServiceUrl
);

$client = new SoapClient($proxyWsdl, $options);

$params = array( /* */ );
$client->someOperation($params);

As you can see, everything is pretty standard except for the proxy bit.

Reason for the proxy

I wrote the proxy to fulfill a requirement by the web service provider that all end-points including the WSDL be processed through an authentication system called siteminder.

The function of the proxy is quite straight forward, if written in linux command line curl it would be something like this:

curl -L -E /location/of/cert.pem -c /tmp/location/of/cookie.jar https://web-service-provider/servicename?wsdl

To be precise:

* Follow all redirections
* specify location of .pem file (and password)
* specify location of cookie jar

This all works fine :)

BUT recently the service provider decided to changes it's WSDL.

It now imports schema files (.xsd), which is not all that bad, except it is relative to the WSDL.

Being relative to the WSDL file means that the SoapClient parser now looks for the schema files from the proxy's location. ERROR, can't find!