How to consume a WCF Web Service that uses custom username validation with a PHP page?

I solved the problem. I had to extends the "SoapHeader" class in PHP to make it compliant with the WS-Security standard.

Here is the solution :

PHP Header class

class WsseAuthHeader extends SoapHeader 
{
    private $wss_ns = 'http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd';
    function __construct($user, $pass, $ns = null) 
    {    
        if ($ns) 
        {        
            $this->wss_ns = $ns;    
        }    

        $auth = new stdClass();    

        $auth->Username = new SoapVar($user, XSD_STRING, NULL, $this->wss_ns, NULL, $this->wss_ns);     
        $auth->Password = new SoapVar($pass, XSD_STRING, NULL, $this->wss_ns, NULL, $this->wss_ns);    
        $username_token = new stdClass();    
        $username_token->UsernameToken = new SoapVar($auth, SOAP_ENC_OBJECT, NULL, $this->wss_ns, 'UsernameToken', $this->wss_ns);     
        $security_sv = new SoapVar(        
                                new SoapVar($username_token, SOAP_ENC_OBJECT, NULL, $this->wss_ns, 'UsernameToken', $this->wss_ns),        
                                SOAP_ENC_OBJECT, NULL, $this->wss_ns, 'Security', $this->wss_ns);    

        parent::__construct($this->wss_ns, 'Security', $security_sv, true);
    }
}

PHP Client call

$options = array( 
            'soap_version'    => SOAP_1_1, 
            'exceptions'      => true, 
            'trace'           => 1, 
            'wdsl_local_copy' => true
            );


$username = "MyUser";
$password = "MyPassword";

$wsse_header = new WsseAuthHeader($username, $password);    

$client = new SoapClient('https://UrlToService/Service.svc?wsdl', $options); 
$client->__setSoapHeaders(array($wsse_header));

try
{
    $phpresponse = $client->Get(); 

    print $phpresponse->GetResult->Version;
    echo "</b><BR/><BR/>";
}
catch(Exception $e) 
{ 
    echo "<h2>Exception Error!</h2></b>"; 
    echo $e->getMessage(); 
}

Hope it will helps someone else!

Thanks to Chris : Connecting to WS-Security protected Web Service with PHP