如何在NuSOAP中使用SSL？

I'm using the NuSOAP library with PHP. How can I start using SSL?

Can I simply replace 'http' with 'https', or do I need to generate keys for NuSOAP?

Server code:

$server = new soap_server();

$server->register("GetMaxFileUpload",
                      array('sLanguage' => 'tns:string'),
                      array('return' => 'tns:getmaxfileupload'),
                      'urn:datalist', 'urn:datalist#GetMaxFileUpload');

$server->service(file_get_contents("php://input"));

Client code:

$client = new    nusoap_client($GLOBALS['gsSOAPserver'].'webservice/uploadmaxfilesize.php');

$sUploadlimit= $client->call('GetMaxFileUpload', array('sLanguage'=>$GLOBALS['gsLanguage']));