location /p/ {
            location ~ ^/p/(?<secure>[\w\-=]+,\d+)(?<file>/.+)$ {
 
                secure_link          $secure;
                secure_link_md5      $secure_link_expires.$file.PASSWORD;
 
                if ($secure_link = "") {
                    return 403;
                }
 
                if ($secure_link == 0) {
                    return 410;
                }
 
                alias  /path/to$file;
            }
 
            return 404;
 
            error_page  403       /forbidden.html;
            error_page  404       /not_found.html;
            error_page  410  =403 /link_expired.html;
        }