SimpleSAML_Utilities::getSecretSalt PHP Method

    public static function getSecretSalt()
    {
        return SimpleSAML\Utils\Config::getSecretSalt();
    }

 /**
  * Get the NameID value.
  *
  * @return string|NULL  The NameID value.
  */
 protected function getValue(array &$state)
 {
     if (!isset($state['Destination']['entityid'])) {
         SimpleSAML_Logger::warning('No SP entity ID - not generating persistent NameID.');
         return NULL;
     }
     $spEntityId = $state['Destination']['entityid'];
     if (!isset($state['Source']['entityid'])) {
         SimpleSAML_Logger::warning('No IdP entity ID - not generating persistent NameID.');
         return NULL;
     }
     $idpEntityId = $state['Source']['entityid'];
     if (!isset($state['Attributes'][$this->attribute]) || count($state['Attributes'][$this->attribute]) === 0) {
         SimpleSAML_Logger::warning('Missing attribute ' . var_export($this->attribute, TRUE) . ' on user - not generating persistent NameID.');
         return NULL;
     }
     if (count($state['Attributes'][$this->attribute]) > 1) {
         SimpleSAML_Logger::warning('More than one value in attribute ' . var_export($this->attribute, TRUE) . ' on user - not generating persistent NameID.');
         return NULL;
     }
     $uid = array_values($state['Attributes'][$this->attribute]);
     /* Just in case the first index is no longer 0. */
     $uid = $uid[0];
     $secretSalt = SimpleSAML_Utilities::getSecretSalt();
     $uidData = 'uidhashbase' . $secretSalt;
     $uidData .= strlen($idpEntityId) . ':' . $idpEntityId;
     $uidData .= strlen($spEntityId) . ':' . $spEntityId;
     $uidData .= strlen($uid) . ':' . $uid;
     $uidData .= $secretSalt;
     return sha1($uidData);
 }