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337a0ee705
If $CFG->enable_read_only_sessions_debug was not enabled, debugging could be enabled part-way through a request when restart_with_write_lock was called. This meant that a diff between the initial and final session would be made during write_close(), although the intial session state was never captured. This generated false positives in the logs, and it thought any variable set in the session was a change from the original value. This ensures that debugging is enabled before the debug flag is allowed to change, preventing false positives.
1513 lines
56 KiB
PHP
1513 lines
56 KiB
PHP
<?php
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// This file is part of Moodle - http://moodle.org/
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//
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// Moodle is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// Moodle is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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/**
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* Session manager class.
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*
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* @package core
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* @copyright 2013 Petr Skoda {@link http://skodak.org}
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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namespace core\session;
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defined('MOODLE_INTERNAL') || die();
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use html_writer;
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/**
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* Session manager, this is the public Moodle API for sessions.
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*
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* Following PHP functions MUST NOT be used directly:
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* - session_start() - not necessary, lib/setup.php starts session automatically,
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* use define('NO_MOODLE_COOKIE', true) if session not necessary.
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* - session_write_close() - use \core\session\manager::write_close() instead.
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* - session_destroy() - use require_logout() instead.
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*
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* @package core
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* @copyright 2013 Petr Skoda {@link http://skodak.org}
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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class manager {
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/** @var int A hard cutoff of maximum stored history */
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const MAXIMUM_STORED_SESSION_HISTORY = 50;
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/** @var int The recent session locks array is reset if there is a time gap more than this value in seconds */
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const SESSION_RESET_GAP_THRESHOLD = 1;
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/** @var handler $handler active session handler instance */
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protected static $handler;
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/** @var bool $sessionactive Is the session active? */
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protected static $sessionactive = null;
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/** @var string $logintokenkey Key used to get and store request protection for login form. */
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protected static $logintokenkey = 'core_auth_login';
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/** @var array Stores the the SESSION before a request is performed, used to check incorrect read-only modes */
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private static $priorsession = [];
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/** @var array Stores the the SESSION after write_close is called, used to check if it was mutated after the session is closed */
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private static $sessionatclose = [];
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/**
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* @var bool Used to trigger the SESSION mutation warning without actually preventing SESSION mutation.
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* This variable is used to "copy" what the $requireslock parameter does in start_session().
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* Once requireslock is set in start_session it's later accessible via $handler->requires_write_lock,
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* When using $CFG->enable_read_only_sessions_debug mode, this variable serves the same purpose without
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* actually setting the handler as requiring a write lock.
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*/
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private static $requireslockdebug;
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/**
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* If the current session is not writeable, abort it, and re-open it
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* requesting (and blocking) until a write lock is acquired.
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* If current session was already opened with an intentional write lock,
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* this call will not do anything.
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* NOTE: Even when using a session handler that does not support non-locking sessions,
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* if the original session was not opened with the explicit intention of being locked,
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* this will still restart your session so that code behaviour matches as closely
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* as practical across environments.
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*
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* @param bool $readonlysession Used by debugging logic to determine if whatever
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* triggered the restart (e.g., a webservice) declared
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* itself as read only.
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*/
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public static function restart_with_write_lock(bool $readonlysession) {
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global $CFG;
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if (!empty($CFG->enable_read_only_sessions_debug)) {
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self::$requireslockdebug = !$readonlysession;
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}
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if (self::$sessionactive && !self::$handler->requires_write_lock()) {
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@self::$handler->abort();
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self::$sessionactive = false;
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self::start_session(true);
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}
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}
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/**
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* Start user session.
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*
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* Note: This is intended to be called only from lib/setup.php!
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*/
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public static function start() {
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global $CFG, $DB, $PERF;
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if (isset(self::$sessionactive)) {
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debugging('Session was already started!', DEBUG_DEVELOPER);
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return;
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}
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// Grab the time before session lock starts.
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$PERF->sessionlock['start'] = microtime(true);
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self::load_handler();
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// Init the session handler only if everything initialised properly in lib/setup.php file
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// and the session is actually required.
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if (empty($DB) or empty($CFG->version) or !defined('NO_MOODLE_COOKIES') or NO_MOODLE_COOKIES or CLI_SCRIPT) {
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self::$sessionactive = false;
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self::init_empty_session();
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return;
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}
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if (defined('READ_ONLY_SESSION') && !empty($CFG->enable_read_only_sessions)) {
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$requireslock = !READ_ONLY_SESSION;
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} else {
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$requireslock = true; // For backwards compatibility, we default to assuming that a lock is needed.
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}
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// By default make the two variables the same. This means that when they are
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// checked below in start_session and write_close there is no possibility for
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// the debug version to "accidentally" execute the debug mode.
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self::$requireslockdebug = $requireslock;
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if (defined('READ_ONLY_SESSION') && !empty($CFG->enable_read_only_sessions_debug)) {
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// Only change the debug variable if READ_ONLY_SESSION is declared,
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// as would happen with the real requireslock variable.
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self::$requireslockdebug = !READ_ONLY_SESSION;
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}
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self::start_session($requireslock);
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}
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/**
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* Handles starting a session.
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*
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* @param bool $requireslock If this is false then no write lock will be acquired,
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* and the session will be read-only.
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*/
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private static function start_session(bool $requireslock) {
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global $PERF, $CFG;
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try {
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self::$handler->init();
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self::$handler->set_requires_write_lock($requireslock);
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self::prepare_cookies();
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$isnewsession = empty($_COOKIE[session_name()]);
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if (!self::$handler->start()) {
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// Could not successfully start/recover session.
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throw new \core\session\exception(get_string('servererror'));
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}
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if ($requireslock) {
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// Grab the time when session lock starts.
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$PERF->sessionlock['gained'] = microtime(true);
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$PERF->sessionlock['wait'] = $PERF->sessionlock['gained'] - $PERF->sessionlock['start'];
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}
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self::initialise_user_session($isnewsession);
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self::$sessionactive = true; // Set here, so the session can be cleared if the security check fails.
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self::check_security();
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if (!$requireslock || !self::$requireslockdebug) {
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self::$priorsession = (array) $_SESSION['SESSION'];
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}
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if (!empty($CFG->enable_read_only_sessions) && isset($_SESSION['SESSION']->cachestore_session)) {
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$caches = join(', ', array_keys($_SESSION['SESSION']->cachestore_session));
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$caches = str_replace('default_session-', '', $caches);
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throw new \moodle_exception("The session caches can not be in the session store when "
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. "enable_read_only_sessions is enabled. Please map all session mode caches to be outside of the "
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. "default session store before enabling this features. Found these definitions in the session: $caches");
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}
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// Link global $USER and $SESSION,
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// this is tricky because PHP does not allow references to references
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// and global keyword uses internally once reference to the $GLOBALS array.
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// The solution is to use the $GLOBALS['USER'] and $GLOBALS['$SESSION']
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// as the main storage of data and put references to $_SESSION.
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$GLOBALS['USER'] = $_SESSION['USER'];
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$_SESSION['USER'] =& $GLOBALS['USER'];
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$GLOBALS['SESSION'] = $_SESSION['SESSION'];
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$_SESSION['SESSION'] =& $GLOBALS['SESSION'];
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} catch (\Exception $ex) {
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self::init_empty_session();
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self::$sessionactive = false;
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throw $ex;
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}
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}
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/**
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* Returns current page performance info.
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*
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* @return array perf info
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*/
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public static function get_performance_info() {
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global $CFG, $PERF;
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if (!session_id()) {
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return array();
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}
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self::load_handler();
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$size = display_size(strlen(session_encode()));
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$handler = get_class(self::$handler);
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$info = array();
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$info['size'] = $size;
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$info['html'] = html_writer::div("Session ($handler): $size", "sessionsize");
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$info['txt'] = "Session ($handler): $size ";
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if (!empty($CFG->debugsessionlock)) {
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$sessionlock = self::get_session_lock_info();
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if (!empty($sessionlock['held'])) {
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// The page displays the footer and the session has been closed.
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$sessionlocktext = "Session lock held: ".number_format($sessionlock['held'], 3)." secs";
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} else {
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// The session hasn't yet been closed and so we assume now with microtime.
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$sessionlockheld = microtime(true) - $PERF->sessionlock['gained'];
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$sessionlocktext = "Session lock open: ".number_format($sessionlockheld, 3)." secs";
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}
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$info['txt'] .= $sessionlocktext;
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$info['html'] .= html_writer::div($sessionlocktext, "sessionlockstart");
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$sessionlockwaittext = "Session lock wait: ".number_format($sessionlock['wait'], 3)." secs";
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$info['txt'] .= $sessionlockwaittext;
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$info['html'] .= html_writer::div($sessionlockwaittext, "sessionlockwait");
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}
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return $info;
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}
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/**
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* Get fully qualified name of session handler class.
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*
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* @return string The name of the handler class
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*/
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public static function get_handler_class() {
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global $CFG, $DB;
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if (PHPUNIT_TEST) {
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return '\core\session\file';
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} else if (!empty($CFG->session_handler_class)) {
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return $CFG->session_handler_class;
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} else if (!empty($CFG->dbsessions) and $DB->session_lock_supported()) {
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return '\core\session\database';
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}
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return '\core\session\file';
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}
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/**
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* Create handler instance.
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*/
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protected static function load_handler() {
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if (self::$handler) {
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return;
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}
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// Find out which handler to use.
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$class = self::get_handler_class();
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self::$handler = new $class();
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}
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/**
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* Empty current session, fill it with not-logged-in user info.
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*
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* This is intended for installation scripts, unit tests and other
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* special areas. Do NOT use for logout and session termination
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* in normal requests!
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*
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* @param mixed $newsid only used after initialising a user session, is this a new user session?
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*/
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public static function init_empty_session(?bool $newsid = null) {
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global $CFG;
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if (isset($GLOBALS['SESSION']->notifications)) {
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// Backup notifications. These should be preserved across session changes until the user fetches and clears them.
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$notifications = $GLOBALS['SESSION']->notifications;
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}
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$GLOBALS['SESSION'] = new \stdClass();
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if (isset($newsid)) {
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$GLOBALS['SESSION']->isnewsessioncookie = $newsid;
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}
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$GLOBALS['USER'] = new \stdClass();
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$GLOBALS['USER']->id = 0;
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if (!empty($notifications)) {
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// Restore notifications.
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$GLOBALS['SESSION']->notifications = $notifications;
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}
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if (isset($CFG->mnet_localhost_id)) {
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$GLOBALS['USER']->mnethostid = $CFG->mnet_localhost_id;
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} else {
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// Not installed yet, the future host id will be most probably 1.
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$GLOBALS['USER']->mnethostid = 1;
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}
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// Link global $USER and $SESSION.
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$_SESSION = array();
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$_SESSION['USER'] =& $GLOBALS['USER'];
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$_SESSION['SESSION'] =& $GLOBALS['SESSION'];
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}
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/**
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* Make sure all cookie and session related stuff is configured properly before session start.
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*/
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protected static function prepare_cookies() {
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global $CFG;
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$cookiesecure = is_moodle_cookie_secure();
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if (!isset($CFG->cookiehttponly)) {
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$CFG->cookiehttponly = 1;
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}
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// Set sessioncookie variable if it isn't already.
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if (!isset($CFG->sessioncookie)) {
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$CFG->sessioncookie = '';
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}
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$sessionname = 'MoodleSession'.$CFG->sessioncookie;
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// Make sure cookie domain makes sense for this wwwroot.
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if (!isset($CFG->sessioncookiedomain)) {
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$CFG->sessioncookiedomain = '';
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} else if ($CFG->sessioncookiedomain !== '') {
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$host = parse_url($CFG->wwwroot, PHP_URL_HOST);
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if ($CFG->sessioncookiedomain !== $host) {
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if (substr($CFG->sessioncookiedomain, 0, 1) === '.') {
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if (!preg_match('|^.*'.preg_quote($CFG->sessioncookiedomain, '|').'$|', $host)) {
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// Invalid domain - it must be end part of host.
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$CFG->sessioncookiedomain = '';
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}
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} else {
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if (!preg_match('|^.*\.'.preg_quote($CFG->sessioncookiedomain, '|').'$|', $host)) {
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// Invalid domain - it must be end part of host.
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$CFG->sessioncookiedomain = '';
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}
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}
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}
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}
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// Make sure the cookiepath is valid for this wwwroot or autodetect if not specified.
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if (!isset($CFG->sessioncookiepath)) {
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$CFG->sessioncookiepath = '';
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}
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if ($CFG->sessioncookiepath !== '/') {
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$path = parse_url($CFG->wwwroot, PHP_URL_PATH).'/';
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if ($CFG->sessioncookiepath === '') {
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$CFG->sessioncookiepath = $path;
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} else {
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if (strpos($path, $CFG->sessioncookiepath) !== 0 or substr($CFG->sessioncookiepath, -1) !== '/') {
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$CFG->sessioncookiepath = $path;
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}
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}
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}
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// Discard session ID from POST, GET and globals to tighten security,
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// this is session fixation prevention.
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unset($GLOBALS[$sessionname]);
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unset($_GET[$sessionname]);
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unset($_POST[$sessionname]);
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unset($_REQUEST[$sessionname]);
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// Compatibility hack for non-browser access to our web interface.
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if (!empty($_COOKIE[$sessionname]) && $_COOKIE[$sessionname] == "deleted") {
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unset($_COOKIE[$sessionname]);
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}
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// Set configuration.
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session_name($sessionname);
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$sessionoptions = [
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'lifetime' => 0,
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'path' => $CFG->sessioncookiepath,
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'domain' => $CFG->sessioncookiedomain,
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'secure' => $cookiesecure,
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'httponly' => $CFG->cookiehttponly,
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];
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if (self::should_use_samesite_none()) {
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// If $samesite is empty, we don't want there to be any SameSite attribute.
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$sessionoptions['samesite'] = 'None';
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}
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session_set_cookie_params($sessionoptions);
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ini_set('session.use_trans_sid', '0');
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ini_set('session.use_only_cookies', '1');
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ini_set('session.use_strict_mode', '0'); // We have custom protection in session init.
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ini_set('session.serialize_handler', 'php'); // We can move to 'php_serialize' after we require PHP 5.5.4 form Moodle.
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// Moodle does normal session timeouts, this is for leftovers only.
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ini_set('session.gc_probability', 1);
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ini_set('session.gc_divisor', 1000);
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ini_set('session.gc_maxlifetime', 60*60*24*4);
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}
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/**
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* Initialise $_SESSION, handles google access
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* and sets up not-logged-in user properly.
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*
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* WARNING: $USER and $SESSION are set up later, do not use them yet!
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*
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* @param bool $newsid is this a new session in first http request?
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*/
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protected static function initialise_user_session($newsid) {
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global $CFG, $DB;
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$sid = session_id();
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if (!$sid) {
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// No session, very weird.
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error_log('Missing session ID, session not started!');
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self::init_empty_session($newsid);
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return;
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}
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if (!$record = $DB->get_record('sessions', array('sid'=>$sid), 'id, sid, state, userid, lastip, timecreated, timemodified')) {
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if (!$newsid) {
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if (!empty($_SESSION['USER']->id)) {
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// This should not happen, just log it, we MUST not produce any output here!
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error_log("Cannot find session record $sid for user ".$_SESSION['USER']->id.", creating new session.");
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}
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// Prevent session fixation attacks.
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session_regenerate_id(true);
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}
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$_SESSION = array();
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}
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unset($sid);
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if (isset($_SESSION['USER']->id)) {
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if (!empty($_SESSION['USER']->realuser)) {
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$userid = $_SESSION['USER']->realuser;
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} else {
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$userid = $_SESSION['USER']->id;
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}
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// Verify timeout first.
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$maxlifetime = $CFG->sessiontimeout;
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$timeout = false;
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if (isguestuser($userid) or empty($userid)) {
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// Ignore guest and not-logged in timeouts, there is very little risk here.
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$timeout = false;
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} else if ($record->timemodified < time() - $maxlifetime) {
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$timeout = true;
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$authsequence = get_enabled_auth_plugins(); // Auths, in sequence.
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foreach ($authsequence as $authname) {
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$authplugin = get_auth_plugin($authname);
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if ($authplugin->ignore_timeout_hook($_SESSION['USER'], $record->sid, $record->timecreated, $record->timemodified)) {
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$timeout = false;
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break;
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}
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}
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}
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if ($timeout) {
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if (defined('NO_SESSION_UPDATE') && NO_SESSION_UPDATE) {
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return;
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}
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session_regenerate_id(true);
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$_SESSION = array();
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$DB->delete_records('sessions', array('id'=>$record->id));
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} else {
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// Update session tracking record.
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$update = new \stdClass();
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$updated = false;
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if ($record->userid != $userid) {
|
|
$update->userid = $record->userid = $userid;
|
|
$updated = true;
|
|
}
|
|
|
|
$ip = getremoteaddr();
|
|
if ($record->lastip != $ip) {
|
|
$update->lastip = $record->lastip = $ip;
|
|
$updated = true;
|
|
}
|
|
|
|
$updatefreq = empty($CFG->session_update_timemodified_frequency) ? 20 : $CFG->session_update_timemodified_frequency;
|
|
|
|
if ($record->timemodified == $record->timecreated) {
|
|
// Always do first update of existing record.
|
|
$update->timemodified = $record->timemodified = time();
|
|
$updated = true;
|
|
|
|
} else if ($record->timemodified < time() - $updatefreq) {
|
|
// Update the session modified flag only once every 20 seconds.
|
|
$update->timemodified = $record->timemodified = time();
|
|
$updated = true;
|
|
}
|
|
|
|
if ($updated && (!defined('NO_SESSION_UPDATE') || !NO_SESSION_UPDATE)) {
|
|
$update->id = $record->id;
|
|
$DB->update_record('sessions', $update);
|
|
}
|
|
|
|
return;
|
|
}
|
|
} else {
|
|
if ($record) {
|
|
// This happens when people switch session handlers...
|
|
session_regenerate_id(true);
|
|
$_SESSION = array();
|
|
$DB->delete_records('sessions', array('id'=>$record->id));
|
|
}
|
|
}
|
|
unset($record);
|
|
|
|
$timedout = false;
|
|
if (!isset($_SESSION['SESSION'])) {
|
|
$_SESSION['SESSION'] = new \stdClass();
|
|
if (!$newsid) {
|
|
$timedout = true;
|
|
}
|
|
}
|
|
|
|
$user = null;
|
|
|
|
if (!empty($CFG->opentowebcrawlers)) {
|
|
if (\core_useragent::is_web_crawler()) {
|
|
$user = guest_user();
|
|
}
|
|
$referer = get_local_referer(false);
|
|
if (!empty($CFG->guestloginbutton) and !$user and !empty($referer)) {
|
|
// Automatically log in users coming from search engine results.
|
|
if (strpos($referer, 'google') !== false ) {
|
|
$user = guest_user();
|
|
} else if (strpos($referer, 'altavista') !== false ) {
|
|
$user = guest_user();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Setup $USER and insert the session tracking record.
|
|
if ($user) {
|
|
self::set_user($user);
|
|
self::add_session_record($user->id);
|
|
} else {
|
|
self::init_empty_session($newsid);
|
|
self::add_session_record(0);
|
|
}
|
|
|
|
if ($timedout) {
|
|
$_SESSION['SESSION']->has_timed_out = true;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Insert new empty session record.
|
|
* @param int $userid
|
|
* @return \stdClass the new record
|
|
*/
|
|
protected static function add_session_record($userid) {
|
|
global $DB;
|
|
$record = new \stdClass();
|
|
$record->state = 0;
|
|
$record->sid = session_id();
|
|
$record->sessdata = null;
|
|
$record->userid = $userid;
|
|
$record->timecreated = $record->timemodified = time();
|
|
$record->firstip = $record->lastip = getremoteaddr();
|
|
|
|
$record->id = $DB->insert_record('sessions', $record);
|
|
|
|
return $record;
|
|
}
|
|
|
|
/**
|
|
* Do various session security checks.
|
|
*
|
|
* WARNING: $USER and $SESSION are set up later, do not use them yet!
|
|
* @throws \core\session\exception
|
|
*/
|
|
protected static function check_security() {
|
|
global $CFG;
|
|
|
|
if (!empty($_SESSION['USER']->id) and !empty($CFG->tracksessionip)) {
|
|
// Make sure current IP matches the one for this session.
|
|
$remoteaddr = getremoteaddr();
|
|
|
|
if (empty($_SESSION['USER']->sessionip)) {
|
|
$_SESSION['USER']->sessionip = $remoteaddr;
|
|
}
|
|
|
|
if ($_SESSION['USER']->sessionip != $remoteaddr) {
|
|
// This is a security feature - terminate the session in case of any doubt.
|
|
self::terminate_current();
|
|
throw new exception('sessionipnomatch2', 'error');
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Login user, to be called from complete_user_login() only.
|
|
* @param \stdClass $user
|
|
*/
|
|
public static function login_user(\stdClass $user) {
|
|
global $DB;
|
|
|
|
// Regenerate session id and delete old session,
|
|
// this helps prevent session fixation attacks from the same domain.
|
|
|
|
$sid = session_id();
|
|
session_regenerate_id(true);
|
|
$DB->delete_records('sessions', array('sid'=>$sid));
|
|
self::add_session_record($user->id);
|
|
|
|
// Let enrol plugins deal with new enrolments if necessary.
|
|
enrol_check_plugins($user);
|
|
|
|
// Setup $USER object.
|
|
self::set_user($user);
|
|
}
|
|
|
|
/**
|
|
* Returns a valid setting for the SameSite cookie attribute.
|
|
*
|
|
* @return string The desired setting for the SameSite attribute on the cookie. Empty string indicates the SameSite attribute
|
|
* should not be set at all.
|
|
*/
|
|
private static function should_use_samesite_none(): bool {
|
|
// We only want None or no attribute at this point. When we have cookie handling compatible with Lax,
|
|
// we can look at checking a setting.
|
|
|
|
// Browser support for none is not consistent yet. There are known issues with Safari, and IE11.
|
|
// Things are stablising, however as they're not stable yet we will deal specifically with the version of chrome
|
|
// that introduces a default of lax, setting it to none for the current version of chrome (2 releases before the change).
|
|
// We also check you are using secure cookies and HTTPS because if you are not running over HTTPS
|
|
// then setting SameSite=None will cause your session cookie to be rejected.
|
|
if (\core_useragent::is_chrome() && \core_useragent::check_chrome_version('78') && is_moodle_cookie_secure()) {
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Terminate current user session.
|
|
* @return void
|
|
*/
|
|
public static function terminate_current() {
|
|
global $DB;
|
|
|
|
if (!self::$sessionactive) {
|
|
self::init_empty_session();
|
|
self::$sessionactive = false;
|
|
return;
|
|
}
|
|
|
|
try {
|
|
$DB->delete_records('external_tokens', array('sid'=>session_id(), 'tokentype'=>EXTERNAL_TOKEN_EMBEDDED));
|
|
} catch (\Exception $ignored) {
|
|
// Probably install/upgrade - ignore this problem.
|
|
}
|
|
|
|
// Initialize variable to pass-by-reference to headers_sent(&$file, &$line).
|
|
$file = null;
|
|
$line = null;
|
|
if (headers_sent($file, $line)) {
|
|
error_log('Cannot terminate session properly - headers were already sent in file: '.$file.' on line '.$line);
|
|
}
|
|
|
|
// Write new empty session and make sure the old one is deleted.
|
|
$sid = session_id();
|
|
session_regenerate_id(true);
|
|
$DB->delete_records('sessions', array('sid'=>$sid));
|
|
self::init_empty_session();
|
|
self::add_session_record($_SESSION['USER']->id); // Do not use $USER here because it may not be set up yet.
|
|
self::write_close();
|
|
}
|
|
|
|
/**
|
|
* No more changes in session expected.
|
|
* Unblocks the sessions, other scripts may start executing in parallel.
|
|
*/
|
|
public static function write_close() {
|
|
global $PERF, $ME, $CFG;
|
|
|
|
if (self::$sessionactive) {
|
|
$requireslock = self::$handler->requires_write_lock();
|
|
if ($requireslock) {
|
|
// Grab the time when session lock is released.
|
|
$PERF->sessionlock['released'] = microtime(true);
|
|
if (!empty($PERF->sessionlock['gained'])) {
|
|
$PERF->sessionlock['held'] = $PERF->sessionlock['released'] - $PERF->sessionlock['gained'];
|
|
}
|
|
$PERF->sessionlock['url'] = me();
|
|
self::update_recent_session_locks($PERF->sessionlock);
|
|
self::sessionlock_debugging();
|
|
}
|
|
|
|
// If debugging, take a snapshot of session at close and compare on shutdown to detect any accidental mutations.
|
|
if (debugging()) {
|
|
self::$sessionatclose = (array) $_SESSION['SESSION'];
|
|
\core_shutdown_manager::register_function('\core\session\manager::check_mutated_closed_session');
|
|
}
|
|
|
|
if (!$requireslock || !self::$requireslockdebug) {
|
|
// Compare the array of the earlier session data with the array now, if
|
|
// there is a difference then a lock is required.
|
|
$arraydiff = self::array_session_diff(
|
|
self::$priorsession,
|
|
(array) $_SESSION['SESSION']
|
|
);
|
|
|
|
if ($arraydiff) {
|
|
$error = "Script $ME defined READ_ONLY_SESSION but the following SESSION attributes were changed:";
|
|
foreach ($arraydiff as $key => $value) {
|
|
$error .= ' $SESSION->' . $key;
|
|
}
|
|
// This will emit an error if debugging is on, even if $CFG->enable_read_only_sessions
|
|
// is not true as we need to surface this class of errors.
|
|
error_log($error); // phpcs:ignore
|
|
}
|
|
}
|
|
}
|
|
|
|
// More control over whether session data
|
|
// is persisted or not.
|
|
if (self::$sessionactive && session_id()) {
|
|
// Write session and release lock only if
|
|
// indication session start was clean.
|
|
self::$handler->write_close();
|
|
} else {
|
|
// Otherwise, if possible lock exists want
|
|
// to clear it, but do not write session.
|
|
// If the $handler has not been set then
|
|
// there is no session to abort.
|
|
if (isset(self::$handler)) {
|
|
@self::$handler->abort();
|
|
}
|
|
}
|
|
|
|
self::$sessionactive = false;
|
|
}
|
|
|
|
/**
|
|
* Checks if the session has been mutated since it was closed.
|
|
* In write_close the session is saved to the variable $sessionatclose
|
|
* If there is a difference between $sessionatclose and the current session,
|
|
* it means a script has erroneously closed the session too early.
|
|
* Script is usually called in shutdown_manager
|
|
*/
|
|
public static function check_mutated_closed_session() {
|
|
global $ME;
|
|
|
|
// Session is still open, mutations are allowed.
|
|
if (self::$sessionactive) {
|
|
return;
|
|
}
|
|
|
|
// Detect if session was cleared.
|
|
if (!isset($_SESSION['SESSION']) && isset(self::$sessionatclose)) {
|
|
debugging("Script $ME cleared the session after it was closed.");
|
|
return;
|
|
} else if (!isset($_SESSION['SESSION'])) {
|
|
// Else session is empty, nothing to check.
|
|
return;
|
|
}
|
|
|
|
// Session is closed - compare the current session to the session when write_close was called.
|
|
$arraydiff = self::array_session_diff(
|
|
self::$sessionatclose,
|
|
(array) $_SESSION['SESSION']
|
|
);
|
|
|
|
if ($arraydiff) {
|
|
$error = "Script $ME mutated the session after it was closed:";
|
|
foreach ($arraydiff as $key => $value) {
|
|
$error .= ' $SESSION->' . $key;
|
|
|
|
// Extra debugging for cachestore session changes.
|
|
if (strpos($key, 'cachestore_') === 0 && is_array($value)) {
|
|
$error .= ': ' . implode(',', array_keys($value));
|
|
}
|
|
}
|
|
debugging($error);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Does the PHP session with given id exist?
|
|
*
|
|
* The session must exist both in session table and actual
|
|
* session backend and the session must not be timed out.
|
|
*
|
|
* Timeout evaluation is simplified, the auth hooks are not executed.
|
|
*
|
|
* @param string $sid
|
|
* @return bool
|
|
*/
|
|
public static function session_exists($sid) {
|
|
global $DB, $CFG;
|
|
|
|
if (empty($CFG->version)) {
|
|
// Not installed yet, do not try to access database.
|
|
return false;
|
|
}
|
|
|
|
// Note: add sessions->state checking here if it gets implemented.
|
|
if (!$record = $DB->get_record('sessions', array('sid' => $sid), 'id, userid, timemodified')) {
|
|
return false;
|
|
}
|
|
|
|
if (empty($record->userid) or isguestuser($record->userid)) {
|
|
// Ignore guest and not-logged-in timeouts, there is very little risk here.
|
|
} else if ($record->timemodified < time() - $CFG->sessiontimeout) {
|
|
return false;
|
|
}
|
|
|
|
// There is no need the existence of handler storage in public API.
|
|
self::load_handler();
|
|
return self::$handler->session_exists($sid);
|
|
}
|
|
|
|
/**
|
|
* Return the number of seconds remaining in the current session.
|
|
* @param string $sid
|
|
*/
|
|
public static function time_remaining($sid) {
|
|
global $DB, $CFG;
|
|
|
|
if (empty($CFG->version)) {
|
|
// Not installed yet, do not try to access database.
|
|
return ['userid' => 0, 'timeremaining' => $CFG->sessiontimeout];
|
|
}
|
|
|
|
// Note: add sessions->state checking here if it gets implemented.
|
|
if (!$record = $DB->get_record('sessions', array('sid' => $sid), 'id, userid, timemodified')) {
|
|
return ['userid' => 0, 'timeremaining' => $CFG->sessiontimeout];
|
|
}
|
|
|
|
if (empty($record->userid) or isguestuser($record->userid)) {
|
|
// Ignore guest and not-logged-in timeouts, there is very little risk here.
|
|
return ['userid' => 0, 'timeremaining' => $CFG->sessiontimeout];
|
|
} else {
|
|
return ['userid' => $record->userid, 'timeremaining' => $CFG->sessiontimeout - (time() - $record->timemodified)];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Fake last access for given session, this prevents session timeout.
|
|
* @param string $sid
|
|
*/
|
|
public static function touch_session($sid) {
|
|
global $DB;
|
|
|
|
// Timeouts depend on core sessions table only, no need to update anything in external stores.
|
|
|
|
$sql = "UPDATE {sessions} SET timemodified = :now WHERE sid = :sid";
|
|
$DB->execute($sql, array('now'=>time(), 'sid'=>$sid));
|
|
}
|
|
|
|
/**
|
|
* Terminate all sessions unconditionally.
|
|
*/
|
|
public static function kill_all_sessions() {
|
|
global $DB;
|
|
|
|
self::terminate_current();
|
|
|
|
self::load_handler();
|
|
self::$handler->kill_all_sessions();
|
|
|
|
try {
|
|
$DB->delete_records('sessions');
|
|
} catch (\dml_exception $ignored) {
|
|
// Do not show any warnings - might be during upgrade/installation.
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Terminate give session unconditionally.
|
|
* @param string $sid
|
|
*/
|
|
public static function kill_session($sid) {
|
|
global $DB;
|
|
|
|
self::load_handler();
|
|
|
|
if ($sid === session_id()) {
|
|
self::write_close();
|
|
}
|
|
|
|
self::$handler->kill_session($sid);
|
|
|
|
$DB->delete_records('sessions', array('sid'=>$sid));
|
|
}
|
|
|
|
/**
|
|
* Terminate all sessions of given user unconditionally.
|
|
* @param int $userid
|
|
* @param string $keepsid keep this sid if present
|
|
*/
|
|
public static function kill_user_sessions($userid, $keepsid = null) {
|
|
global $DB;
|
|
|
|
$sessions = $DB->get_records('sessions', array('userid'=>$userid), 'id DESC', 'id, sid');
|
|
foreach ($sessions as $session) {
|
|
if ($keepsid and $keepsid === $session->sid) {
|
|
continue;
|
|
}
|
|
self::kill_session($session->sid);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Terminate other sessions of current user depending
|
|
* on $CFG->limitconcurrentlogins restriction.
|
|
*
|
|
* This is expected to be called right after complete_user_login().
|
|
*
|
|
* NOTE:
|
|
* * Do not use from SSO auth plugins, this would not work.
|
|
* * Do not use from web services because they do not have sessions.
|
|
*
|
|
* @param int $userid
|
|
* @param string $sid session id to be always keep, usually the current one
|
|
* @return void
|
|
*/
|
|
public static function apply_concurrent_login_limit($userid, $sid = null) {
|
|
global $CFG, $DB;
|
|
|
|
// NOTE: the $sid parameter is here mainly to allow testing,
|
|
// in most cases it should be current session id.
|
|
|
|
if (isguestuser($userid) or empty($userid)) {
|
|
// This applies to real users only!
|
|
return;
|
|
}
|
|
|
|
if (empty($CFG->limitconcurrentlogins) or $CFG->limitconcurrentlogins < 0) {
|
|
return;
|
|
}
|
|
|
|
$count = $DB->count_records('sessions', array('userid' => $userid));
|
|
|
|
if ($count <= $CFG->limitconcurrentlogins) {
|
|
return;
|
|
}
|
|
|
|
$i = 0;
|
|
$select = "userid = :userid";
|
|
$params = array('userid' => $userid);
|
|
if ($sid) {
|
|
if ($DB->record_exists('sessions', array('sid' => $sid, 'userid' => $userid))) {
|
|
$select .= " AND sid <> :sid";
|
|
$params['sid'] = $sid;
|
|
$i = 1;
|
|
}
|
|
}
|
|
|
|
$sessions = $DB->get_records_select('sessions', $select, $params, 'timecreated DESC', 'id, sid');
|
|
foreach ($sessions as $session) {
|
|
$i++;
|
|
if ($i <= $CFG->limitconcurrentlogins) {
|
|
continue;
|
|
}
|
|
self::kill_session($session->sid);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Set current user.
|
|
*
|
|
* @param \stdClass $user record
|
|
*/
|
|
public static function set_user(\stdClass $user) {
|
|
global $ADMIN;
|
|
$GLOBALS['USER'] = $user;
|
|
unset($GLOBALS['USER']->description); // Conserve memory.
|
|
unset($GLOBALS['USER']->password); // Improve security.
|
|
if (isset($GLOBALS['USER']->lang)) {
|
|
// Make sure it is a valid lang pack name.
|
|
$GLOBALS['USER']->lang = clean_param($GLOBALS['USER']->lang, PARAM_LANG);
|
|
}
|
|
|
|
// Relink session with global $USER just in case it got unlinked somehow.
|
|
$_SESSION['USER'] =& $GLOBALS['USER'];
|
|
|
|
// Nullify the $ADMIN tree global. If we're changing users, then this is now stale and must be generated again if needed.
|
|
$ADMIN = null;
|
|
|
|
// Init session key.
|
|
sesskey();
|
|
|
|
// Make sure the user is correct in web server access logs.
|
|
set_access_log_user();
|
|
}
|
|
|
|
/**
|
|
* Periodic timed-out session cleanup.
|
|
*/
|
|
public static function gc() {
|
|
global $CFG, $DB;
|
|
|
|
// This may take a long time...
|
|
\core_php_time_limit::raise();
|
|
|
|
$maxlifetime = $CFG->sessiontimeout;
|
|
|
|
try {
|
|
// Kill all sessions of deleted and suspended users without any hesitation.
|
|
$rs = $DB->get_recordset_select('sessions', "userid IN (SELECT id FROM {user} WHERE deleted <> 0 OR suspended <> 0)", array(), 'id DESC', 'id, sid');
|
|
foreach ($rs as $session) {
|
|
self::kill_session($session->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
// Kill sessions of users with disabled plugins.
|
|
$authsequence = get_enabled_auth_plugins();
|
|
$authsequence = array_flip($authsequence);
|
|
unset($authsequence['nologin']); // No login means user cannot login.
|
|
$authsequence = array_flip($authsequence);
|
|
|
|
list($notplugins, $params) = $DB->get_in_or_equal($authsequence, SQL_PARAMS_QM, '', false);
|
|
$rs = $DB->get_recordset_select('sessions', "userid IN (SELECT id FROM {user} WHERE auth $notplugins)", $params, 'id DESC', 'id, sid');
|
|
foreach ($rs as $session) {
|
|
self::kill_session($session->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
// Now get a list of time-out candidates - real users only.
|
|
$sql = "SELECT u.*, s.sid, s.timecreated AS s_timecreated, s.timemodified AS s_timemodified
|
|
FROM {user} u
|
|
JOIN {sessions} s ON s.userid = u.id
|
|
WHERE s.timemodified < :purgebefore AND u.id <> :guestid";
|
|
$params = array('purgebefore' => (time() - $maxlifetime), 'guestid'=>$CFG->siteguest);
|
|
|
|
$authplugins = array();
|
|
foreach ($authsequence as $authname) {
|
|
$authplugins[$authname] = get_auth_plugin($authname);
|
|
}
|
|
$rs = $DB->get_recordset_sql($sql, $params);
|
|
foreach ($rs as $user) {
|
|
foreach ($authplugins as $authplugin) {
|
|
/** @var \auth_plugin_base $authplugin*/
|
|
if ($authplugin->ignore_timeout_hook($user, $user->sid, $user->s_timecreated, $user->s_timemodified)) {
|
|
continue 2;
|
|
}
|
|
}
|
|
self::kill_session($user->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
// Delete expired sessions for guest user account, give them larger timeout, there is no security risk here.
|
|
$params = array('purgebefore' => (time() - ($maxlifetime * 5)), 'guestid'=>$CFG->siteguest);
|
|
$rs = $DB->get_recordset_select('sessions', 'userid = :guestid AND timemodified < :purgebefore', $params, 'id DESC', 'id, sid');
|
|
foreach ($rs as $session) {
|
|
self::kill_session($session->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
// Delete expired sessions for userid = 0 (not logged in), better kill them asap to release memory.
|
|
$params = array('purgebefore' => (time() - $maxlifetime));
|
|
$rs = $DB->get_recordset_select('sessions', 'userid = 0 AND timemodified < :purgebefore', $params, 'id DESC', 'id, sid');
|
|
foreach ($rs as $session) {
|
|
self::kill_session($session->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
// Cleanup letfovers from the first browser access because it may set multiple cookies and then use only one.
|
|
$params = array('purgebefore' => (time() - 60*3));
|
|
$rs = $DB->get_recordset_select('sessions', 'userid = 0 AND timemodified = timecreated AND timemodified < :purgebefore', $params, 'id ASC', 'id, sid');
|
|
foreach ($rs as $session) {
|
|
self::kill_session($session->sid);
|
|
}
|
|
$rs->close();
|
|
|
|
} catch (\Exception $ex) {
|
|
debugging('Error gc-ing sessions: '.$ex->getMessage(), DEBUG_NORMAL, $ex->getTrace());
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Is current $USER logged-in-as somebody else?
|
|
* @return bool
|
|
*/
|
|
public static function is_loggedinas() {
|
|
return !empty($GLOBALS['USER']->realuser);
|
|
}
|
|
|
|
/**
|
|
* Returns the $USER object ignoring current login-as session
|
|
* @return \stdClass user object
|
|
*/
|
|
public static function get_realuser() {
|
|
if (self::is_loggedinas()) {
|
|
return $_SESSION['REALUSER'];
|
|
} else {
|
|
return $GLOBALS['USER'];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Login as another user - no security checks here.
|
|
* @param int $userid
|
|
* @param \context $context
|
|
* @param bool $generateevent Set to false to prevent the loginas event to be generated
|
|
* @return void
|
|
*/
|
|
public static function loginas($userid, \context $context, $generateevent = true) {
|
|
global $USER;
|
|
|
|
if (self::is_loggedinas()) {
|
|
return;
|
|
}
|
|
|
|
// Switch to fresh new $_SESSION.
|
|
$_SESSION = array();
|
|
$_SESSION['REALSESSION'] = clone($GLOBALS['SESSION']);
|
|
$GLOBALS['SESSION'] = new \stdClass();
|
|
$_SESSION['SESSION'] =& $GLOBALS['SESSION'];
|
|
|
|
// Create the new $USER object with all details and reload needed capabilities.
|
|
$_SESSION['REALUSER'] = clone($GLOBALS['USER']);
|
|
$user = get_complete_user_data('id', $userid);
|
|
$user->realuser = $_SESSION['REALUSER']->id;
|
|
$user->loginascontext = $context;
|
|
|
|
// Let enrol plugins deal with new enrolments if necessary.
|
|
enrol_check_plugins($user);
|
|
|
|
if ($generateevent) {
|
|
// Create event before $USER is updated.
|
|
$event = \core\event\user_loggedinas::create(
|
|
array(
|
|
'objectid' => $USER->id,
|
|
'context' => $context,
|
|
'relateduserid' => $userid,
|
|
'other' => array(
|
|
'originalusername' => fullname($USER, true),
|
|
'loggedinasusername' => fullname($user, true)
|
|
)
|
|
)
|
|
);
|
|
}
|
|
|
|
// Set up global $USER.
|
|
\core\session\manager::set_user($user);
|
|
|
|
if ($generateevent) {
|
|
$event->trigger();
|
|
}
|
|
|
|
// Queue migrating the messaging data, if we need to.
|
|
if (!get_user_preferences('core_message_migrate_data', false, $userid)) {
|
|
// Check if there are any legacy messages to migrate.
|
|
if (\core_message\helper::legacy_messages_exist($userid)) {
|
|
\core_message\task\migrate_message_data::queue_task($userid);
|
|
} else {
|
|
set_user_preference('core_message_migrate_data', true, $userid);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Add a JS session keepalive to the page.
|
|
*
|
|
* A JS session keepalive script will be called to update the session modification time every $frequency seconds.
|
|
*
|
|
* Upon failure, the specified error message will be shown to the user.
|
|
*
|
|
* @param string $identifier The string identifier for the message to show on failure.
|
|
* @param string $component The string component for the message to show on failure.
|
|
* @param int $frequency The update frequency in seconds.
|
|
* @param int $timeout The timeout of each request in seconds.
|
|
* @throws \coding_exception IF the frequency is longer than the session lifetime.
|
|
*/
|
|
public static function keepalive($identifier = 'sessionerroruser', $component = 'error', $frequency = null, $timeout = 0) {
|
|
global $CFG, $PAGE;
|
|
|
|
if ($frequency) {
|
|
if ($frequency > $CFG->sessiontimeout) {
|
|
// Sanity check the frequency.
|
|
throw new \coding_exception('Keepalive frequency is longer than the session lifespan.');
|
|
}
|
|
} else {
|
|
// A frequency of sessiontimeout / 10 matches the timeouts in core/network amd module.
|
|
$frequency = $CFG->sessiontimeout / 10;
|
|
}
|
|
|
|
$PAGE->requires->js_call_amd('core/network', 'keepalive', array(
|
|
$frequency,
|
|
$timeout,
|
|
$identifier,
|
|
$component
|
|
));
|
|
}
|
|
|
|
/**
|
|
* Generate a new login token and store it in the session.
|
|
*
|
|
* @return array The current login state.
|
|
*/
|
|
private static function create_login_token() {
|
|
global $SESSION;
|
|
|
|
$state = [
|
|
'token' => random_string(32),
|
|
'created' => time() // Server time - not user time.
|
|
];
|
|
|
|
if (!isset($SESSION->logintoken)) {
|
|
$SESSION->logintoken = [];
|
|
}
|
|
|
|
// Overwrite any previous values.
|
|
$SESSION->logintoken[self::$logintokenkey] = $state;
|
|
|
|
return $state;
|
|
}
|
|
|
|
/**
|
|
* Get the current login token or generate a new one.
|
|
*
|
|
* All login forms generated from Moodle must include a login token
|
|
* named "logintoken" with the value being the result of this function.
|
|
* Logins will be rejected if they do not include this token as well as
|
|
* the username and password fields.
|
|
*
|
|
* @return string The current login token.
|
|
*/
|
|
public static function get_login_token() {
|
|
global $CFG, $SESSION;
|
|
|
|
$state = false;
|
|
|
|
if (!isset($SESSION->logintoken)) {
|
|
$SESSION->logintoken = [];
|
|
}
|
|
|
|
if (array_key_exists(self::$logintokenkey, $SESSION->logintoken)) {
|
|
$state = $SESSION->logintoken[self::$logintokenkey];
|
|
}
|
|
if (empty($state)) {
|
|
$state = self::create_login_token();
|
|
}
|
|
|
|
// Check token lifespan.
|
|
if ($state['created'] < (time() - $CFG->sessiontimeout)) {
|
|
$state = self::create_login_token();
|
|
}
|
|
|
|
// Return the current session login token.
|
|
if (array_key_exists('token', $state)) {
|
|
return $state['token'];
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Check the submitted value against the stored login token.
|
|
*
|
|
* @param mixed $token The value submitted in the login form that we are validating.
|
|
* If false is passed for the token, this function will always return true.
|
|
* @return boolean If the submitted token is valid.
|
|
*/
|
|
public static function validate_login_token($token = false) {
|
|
global $CFG, $SESSION;
|
|
|
|
if (!empty($CFG->alternateloginurl) || !empty($CFG->disablelogintoken)) {
|
|
// An external login page cannot generate the login token we need to protect CSRF on
|
|
// login requests.
|
|
// Other custom login workflows may skip this check by setting disablelogintoken in config.
|
|
return true;
|
|
}
|
|
if ($token === false) {
|
|
// authenticate_user_login is a core function was extended to validate tokens.
|
|
// For existing uses other than the login form it does not
|
|
// validate that a token was generated.
|
|
// Some uses that do not validate the token are login/token.php,
|
|
// or an auth plugin like auth/ldap/auth.php.
|
|
return true;
|
|
}
|
|
|
|
$currenttoken = self::get_login_token();
|
|
|
|
// We need to clean the login token so the old one is not valid again.
|
|
unset($SESSION->logintoken);
|
|
|
|
if ($currenttoken !== $token) {
|
|
// Fail the login.
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Get the recent session locks array.
|
|
*
|
|
* @return array Recent session locks array.
|
|
*/
|
|
public static function get_recent_session_locks() {
|
|
global $SESSION;
|
|
|
|
if (!isset($SESSION->recentsessionlocks)) {
|
|
// This will hold the pages that blocks other page.
|
|
$SESSION->recentsessionlocks = array();
|
|
}
|
|
|
|
return $SESSION->recentsessionlocks;
|
|
}
|
|
|
|
/**
|
|
* Updates the recent session locks.
|
|
*
|
|
* This function will store session lock info of all the pages visited.
|
|
*
|
|
* @param array $sessionlock Session lock array.
|
|
*/
|
|
public static function update_recent_session_locks($sessionlock) {
|
|
global $CFG, $SESSION;
|
|
|
|
if (empty($CFG->debugsessionlock)) {
|
|
return;
|
|
}
|
|
|
|
$readonlysession = defined('READ_ONLY_SESSION') && READ_ONLY_SESSION;
|
|
$readonlydebugging = !empty($CFG->enable_read_only_sessions) || !empty($CFG->enable_read_only_sessions_debug);
|
|
if ($readonlysession && $readonlydebugging) {
|
|
return;
|
|
}
|
|
|
|
$SESSION->recentsessionlocks = self::get_recent_session_locks();
|
|
array_push($SESSION->recentsessionlocks, $sessionlock);
|
|
|
|
self::cleanup_recent_session_locks();
|
|
}
|
|
|
|
/**
|
|
* Reset recent session locks array if there is a time gap more than SESSION_RESET_GAP_THRESHOLD.
|
|
*/
|
|
public static function cleanup_recent_session_locks() {
|
|
global $SESSION;
|
|
|
|
$locks = self::get_recent_session_locks();
|
|
|
|
if (count($locks) > self::MAXIMUM_STORED_SESSION_HISTORY) {
|
|
// Keep the last MAXIMUM_STORED_SESSION_HISTORY locks and ignore the rest.
|
|
$locks = array_slice($locks, -1 * self::MAXIMUM_STORED_SESSION_HISTORY);
|
|
}
|
|
|
|
if (count($locks) > 2) {
|
|
for ($i = count($locks) - 1; $i > 0; $i--) {
|
|
// Calculate the gap between session locks.
|
|
$gap = $locks[$i]['released'] - $locks[$i - 1]['start'];
|
|
if ($gap >= self::SESSION_RESET_GAP_THRESHOLD) {
|
|
// Remove previous locks if the gap is 1 second or more.
|
|
$SESSION->recentsessionlocks = array_slice($locks, $i);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Get the page that blocks other pages at a specific timestamp.
|
|
*
|
|
* Look for a page whose lock was gained before that timestamp, and released after that timestamp.
|
|
*
|
|
* @param float $time Time before session lock starts.
|
|
* @return array|null
|
|
*/
|
|
public static function get_locked_page_at($time) {
|
|
$recentsessionlocks = self::get_recent_session_locks();
|
|
foreach ($recentsessionlocks as $recentsessionlock) {
|
|
if ($time >= $recentsessionlock['gained'] &&
|
|
$time <= $recentsessionlock['released']) {
|
|
return $recentsessionlock;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Display the page which blocks other pages.
|
|
*
|
|
* @return string
|
|
*/
|
|
public static function display_blocking_page() {
|
|
global $PERF;
|
|
|
|
$page = self::get_locked_page_at($PERF->sessionlock['start']);
|
|
$output = "Script ".me()." was blocked for ";
|
|
$output .= number_format($PERF->sessionlock['wait'], 3);
|
|
if ($page != null) {
|
|
$output .= " second(s) by script: ";
|
|
$output .= $page['url'];
|
|
} else {
|
|
$output .= " second(s) by an unknown script.";
|
|
}
|
|
|
|
return $output;
|
|
}
|
|
|
|
/**
|
|
* Get session lock info of the current page.
|
|
*
|
|
* @return array
|
|
*/
|
|
public static function get_session_lock_info() {
|
|
global $PERF;
|
|
|
|
if (!isset($PERF->sessionlock)) {
|
|
return null;
|
|
}
|
|
return $PERF->sessionlock;
|
|
}
|
|
|
|
/**
|
|
* Display debugging info about slow and blocked script.
|
|
*/
|
|
public static function sessionlock_debugging() {
|
|
global $CFG, $PERF;
|
|
|
|
if (!empty($CFG->debugsessionlock)) {
|
|
if (isset($PERF->sessionlock['held']) && $PERF->sessionlock['held'] > $CFG->debugsessionlock) {
|
|
debugging("Script ".me()." locked the session for ".number_format($PERF->sessionlock['held'], 3)
|
|
." seconds, it should close the session using \core\session\manager::write_close().", DEBUG_NORMAL);
|
|
}
|
|
|
|
if (isset($PERF->sessionlock['wait']) && $PERF->sessionlock['wait'] > $CFG->debugsessionlock) {
|
|
$output = self::display_blocking_page();
|
|
debugging($output, DEBUG_DEVELOPER);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Compares two arrays and outputs the difference.
|
|
*
|
|
* Note - checking between objects and array type is only done at the top level.
|
|
* Any changes in types below the top level will not be detected.
|
|
* However, if their values are the same, they will be treated as equal.
|
|
*
|
|
* Any changes, such as removals, edits or additions will be detected.
|
|
*
|
|
* @param array $previous
|
|
* @param array $current
|
|
* @return array
|
|
*/
|
|
private static function array_session_diff(array $previous, array $current): array {
|
|
// To use array_udiff_uassoc, the first array must have the most keys; this ensures every key is checked.
|
|
// To do this, we first need to sort them by the length of their keys.
|
|
$arrays = [$current, $previous];
|
|
|
|
// Sort them by the length of their keys.
|
|
usort($arrays, function ($a, $b) {
|
|
return count(array_keys($b)) - count(array_keys($a));
|
|
});
|
|
|
|
// The largest is the first value in the $arrays, after sorting.
|
|
// The smallest is then the last one.
|
|
// If they are the same size, it does not matter which is which.
|
|
$largest = $arrays[0];
|
|
$smallest = $arrays[1];
|
|
|
|
// Defines a function that casts the values to arrays.
|
|
// This is so the properties are compared, instead any object's identities.
|
|
$casttoarray = function ($value) {
|
|
return json_decode(json_encode($value), true);
|
|
};
|
|
|
|
// Defines a function that compares all keys by their string value.
|
|
$keycompare = function ($a, $b) {
|
|
return strcmp($a, $b);
|
|
};
|
|
|
|
// Defines a function that compares all values by first their type, and then their values.
|
|
// If the value contains any objects, they are cast to arrays before comparison.
|
|
$valcompare = function ($a, $b) use ($casttoarray) {
|
|
// First compare type.
|
|
// If they are not the same type, they are definitely not the same.
|
|
// Note we do not check types recursively.
|
|
if (gettype($a) !== gettype($b)) {
|
|
return 1;
|
|
}
|
|
|
|
// Next compare value. Cast any objects to arrays to compare their properties,
|
|
// instead of the identitiy of the object itself.
|
|
$v1 = $casttoarray($a);
|
|
$v2 = $casttoarray($b);
|
|
|
|
if ($v1 !== $v2) {
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
};
|
|
|
|
// Apply the comparison functions to the two given session arrays,
|
|
// making sure to use the largest array first, so that all keys are considered.
|
|
return array_udiff_uassoc($largest, $smallest, $valcompare, $keycompare);
|
|
}
|
|
}
|