SOAP Error

# Configuration parameters:
  $user = 'benutzername';
  $pass = 'pwpwpw';
  $url  = 'https://liveconfig.hoster4you.net:8443/liveconfig/soap';


  # Construct WSDL URL
  $wsdl_url = $url
             .'?wsdl'
             .'&l=' . urlencode($user)
             .'&p=' . urlencode($pass);


  # Create SOAP client
  $client = new SoapClient($wsdl_url,
                           array('style'    => SOAP_DOCUMENT,
                                 'use'      => SOAP_LITERAL,
                                )
                          );


  # Construct SOAP token:
  $ts = gmdate("Y-m-d") . "T" . gmdate("H:i:s") . ".000Z";
  $token = base64_encode(hash_hmac('sha1',
                                   'LiveConfig' . $user . 'TestSayHello' . $ts,
                                   $pass,
                                   true
                                  )
                        );


  $auth = array('login'     => $user,
                'timestamp' => $ts,
                'token'     => $token);
 
  $params = array('auth'      => $auth,
                  'firstname' => 'John',
                  'lastname'  => 'Doe');


  try {
    $response = $client->TestSayHello($params);
  } catch (SoapFault $soapFault) {
    die("Error while calling Web Service: " . $soapFault->faultstring . "\n");
  }


  echo "Response: " . $response->greeting . "\n";


?>