moodle/theme/javascript.php
David Woloszyn 7679452caf MDL-77846 core: Make endpoint revision number checks stricter
In some places we prevented cache poisoning, in others we did not. We
also did not place any restriction on the minimum value for a revision.

This change introduces a new set of functions for configonly endpoints
which validates the revision numbers passed in. If the revision is
either too old, or too new, it is rejected and the file content is not
cached. The content is still served, but caching headers are not sent,
and any local storage caching is prevented.

The current time is used as the maximum version, with 60 seconds added
to allow for any clock skew between cluster nodes. Previously some
locations used one hour, but there should never be such a large clock
skew on a correctly configured system.

Co-authored-by: Andrew Nicols <andrew@nicols.co.uk>
2023-10-04 01:24:19 +00:00

112 lines
4.1 KiB
PHP

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This file is responsible for serving the one huge CSS of each theme.
*
* @package core
* @copyright 2009 Petr Skoda (skodak) {@link http://skodak.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
// disable moodle specific debug messages and any errors in output,
// comment out when debugging or better look into error log!
define('NO_DEBUG_DISPLAY', true);
// we need just the values from config.php and minlib.php
define('ABORT_AFTER_CONFIG', true);
require('../config.php'); // this stops immediately at the beginning of lib/setup.php
require_once("$CFG->dirroot/lib/jslib.php");
if ($slashargument = min_get_slash_argument()) {
$slashargument = ltrim($slashargument, '/');
if (substr_count($slashargument, '/') < 2) {
header('HTTP/1.0 404 not found');
die('Slash argument must contain both a revision and a file path');
}
// image must be last because it may contain "/"
list($themename, $rev, $type) = explode('/', $slashargument, 3);
$themename = min_clean_param($themename, 'SAFEDIR');
$rev = min_clean_param($rev, 'INT');
$type = min_clean_param($type, 'SAFEDIR');
} else {
$themename = min_optional_param('theme', 'standard', 'SAFEDIR');
$rev = min_optional_param('rev', -1, 'INT');
$type = min_optional_param('type', 'head', 'RAW');
}
if (!min_is_revision_valid_and_current($rev)) {
// If the rev is invalid, normalise it to -1 to disable all caching.
$rev = -1;
}
if ($type !== 'head' and $type !== 'footer') {
header('HTTP/1.0 404 not found');
die('Theme was not found, sorry.');
}
if (file_exists("$CFG->dirroot/theme/$themename/config.php")) {
// exists
} else if (!empty($CFG->themedir) and file_exists("$CFG->themedir/$themename/config.php")) {
// exists
} else {
header('HTTP/1.0 404 not found');
die('Theme was not found, sorry.');
}
$candidate = "$CFG->localcachedir/theme/$rev/$themename/javascript_$type.js";
$etag = sha1("$rev/$themename/$type");
if ($rev > 0 and file_exists($candidate)) {
if (!empty($_SERVER['HTTP_IF_NONE_MATCH']) || !empty($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
// we do not actually need to verify the etag value because our files
// never change in cache because we increment the rev parameter
js_send_unmodified(filemtime($candidate), $etag);
}
js_send_cached($candidate, $etag);
}
//=================================================================================
// ok, now we need to start normal moodle script, we need to load all libs and $DB
define('ABORT_AFTER_CONFIG_CANCEL', true);
define('NO_MOODLE_COOKIES', true); // Session not used here
define('NO_UPGRADE_CHECK', true); // Ignore upgrade check
require("$CFG->dirroot/lib/setup.php");
$theme = theme_config::load($themename);
$themerev = theme_get_revision();
if ($themerev <= 0 or $rev != $themerev) {
// Do not send caching headers if they do not request current revision,
// we do not want to pollute browser caches with outdated JS.
js_send_uncached($theme->javascript_content($type));
}
make_localcache_directory('theme', false);
js_write_cache_file_content($candidate, core_minify::js_files($theme->javascript_files($type)));
// Verify nothing failed in cache file creation.
clearstatcache();
if (file_exists($candidate)) {
js_send_cached($candidate, $etag);
}
js_send_uncached($theme->javascript_content($type));