织梦dedecms出现系统基本参数空白或显示Call to undefined function make_hash()

function make_hash() {     $rand = dede_random_bytes(16);     $_SESSION['token'] = ($rand === FALSE)         ? md5(uniqid(mt_rand(), TRUE))         : bin2hex($rand);     return $_SESSION['token']; }  function dede_random_bytes($length) {     if (empty($length) OR !ctype_digit((string) $length)) {         return FALSE;     }     if (function_exists('random_bytes')) {         try {             return random_bytes((int) $length);         } catch (Exception $e) {             return FALSE;         }     }     if (defined('MCRYPT_DEV_URANDOM') && ($output = mcrypt_create_iv($length, MCRYPT_DEV_URANDOM)) !== FALSE) {         return $output;     }     if (is_readable('/dev/urandom') && ($fp = fopen('/dev/urandom', 'rb')) !== FALSE) {         is_php('5.4') && stream_set_chunk_size($fp, $length);         $output = fread($fp, $length);         fclose($fp);         if ($output !== FALSE) {             return $output;         }     }     if (function_exists('openssl_random_pseudo_bytes')) {         return openssl_random_pseudo_bytes($length);     }     return FALSE; }