public function getKeydata()
 {
     // Check if dnssec is enabled on this interface
     if ($this->findNamespace('secDNS')) {
         $xpath = $this->xPath();
         $result = $xpath->query('/epp:epp/epp:response/epp:extension/secDNS:infData/*');
         $keys = array();
         if (count($result) > 0) {
             foreach ($result as $keydata) {
                 $secdns = new eppSecdns();
                 $secdns->setKeytag($result->item(0)->getElementsByTagName('keyTag')->item(0)->nodeValue);
                 $secdns->setAlgorithm($result->item(0)->getElementsByTagName('alg')->item(0)->nodeValue);
                 $secdns->setDigestType($result->item(0)->getElementsByTagName('digestType')->item(0)->nodeValue);
                 $secdns->setDigest($result->item(0)->getElementsByTagName('digest')->item(0)->nodeValue);
                 $keys[] = $secdns;
             }
         }
         return $keys;
     }
     return null;
 }