--- /dev/null
+<?php //$Id$
+
+/**
+ * Class handling all session and cookies related stuff.
+ */
+class moodle_session {
+ private $session;
+
+ function __construct() {
+ global $CFG;
+
+ $this->prepare_cookies();
+ $this->init_session_storage();
+
+ if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
+ $this->sid_start_ob();
+ }
+
+ if (!NO_MOODLE_COOKIES) {
+ session_name('MoodleSession'.$CFG->sessioncookie);
+ session_set_cookie_params(0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+ @session_start();
+ if (!isset($_SESSION['SESSION'])) {
+ $_SESSION['SESSION'] = new object();
+ $_SESSION['SESSION']->session_test = random_string(10);
+ if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
+ $_SESSION['SESSION']->has_timed_out = true;
+ }
+ setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+ $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
+ }
+ if (!isset($_SESSION['USER'])) {
+ $_SESSION['USER'] = new object();
+ }
+
+ if (!isset($_SESSION['USER']->id)) {
+ $_SESSION['USER']->id = 0; // to enable proper function of $CFG->notloggedinroleid hack
+ if (isset($CFG->mnet_localhost_id)) {
+ $_SESSION['USER']->mnethostid = $CFG->mnet_localhost_id;
+ }
+ }
+
+ $this->session = null;
+
+ } else {
+ $this->session = new object();
+ }
+ }
+
+ /**
+ * Verify session, this detects problems with "switched" sessions
+ * or multiple different wwwroot used at the same time.
+ */
+ public function session_verify() {
+ global $CFG;
+
+ /// disable checks when working in cookieless mode
+ if (empty($CFG->usesid) || !empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
+ if ($this->session != NULL) {
+ if (empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
+ $this->report_session_error();
+ } else if (isset($this->session->session_test) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] != $this->session->session_test) {
+ $this->report_session_error();
+ }
+ }
+ }
+ }
+
+ /**
+ * Report serious problem detected in suer session
+ */
+ function report_session_error() {
+ global $CFG, $FULLME;
+
+ if (empty($CFG->lang)) {
+ $CFG->lang = "en";
+ }
+ // Set up default theme and locale
+ theme_setup();
+ moodle_setlocale();
+
+ //clear session cookies
+ setcookie('MoodleSession'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+ setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+
+ //increment database error counters
+ if (isset($CFG->session_error_counter)) {
+ set_config('session_error_counter', 1 + $CFG->session_error_counter);
+ } else {
+ set_config('session_error_counter', 1);
+ }
+ redirect($FULLME, get_string('sessionerroruser2', 'error'), 5);
+ }
+
+ /**
+ * Terminates active moodle session
+ */
+ public function terminate() {
+ global $CFG, $SESSION, $USER;
+
+ // Initialize variable to pass-by-reference to headers_sent(&$file, &$line)
+ $file = null;
+ $line = null;
+ if (headers_sent($file, $line)) {
+ error_log('MoodleSessionTest cookie could not be set in moodlelib.php:'.__LINE__);
+ error_log('Headers were already sent in file: '.$file.' on line '.$line);
+ } else {
+ setcookie('MoodleSessionTest'.$CFG->sessioncookie, '', time() - 3600, $CFG->sessioncookiepath, '', $CFG->cookiesecure, $CFG->cookiehttponly);
+ }
+
+ $this->session = new object();
+ $_SESSION = array();
+
+ $USER = new object();
+ $USER->id = 0;
+ if (isset($CFG->mnet_localhost_id)) {
+ $USER->mnethostid = $CFG->mnet_localhost_id;
+ }
+
+ @session_write_close();
+ }
+
+
+ public function __set($name, $value) {
+ if (!is_null($this->session)) {
+ $this->session->{$name} = $value;
+ } else {
+ $_SESSION['SESSION']->{$name} = $value;
+ }
+ }
+
+ public function &__get($name) { // this is a weird hack for this stupid bug http://bugs.php.net/bug.php?id=39449
+ if (!is_null($this->session)) {
+ return $this->session->{$name};
+ } else {
+ return $_SESSION['SESSION']->{$name};
+ }
+ }
+
+ public function __isset($name) {
+ if (!is_null($this->session)) {
+ return isset($this->session->{$name});
+ } else {
+ return isset($_SESSION['SESSION']->{$name});
+ }
+ }
+
+ public function __unset($name) {
+ if (!is_null($this->session)) {
+ unset($this->session->{$name});
+ } else {
+ unset($_SESSION['SESSION']->{$name});
+ }
+ }
+
+ /**
+ * Prepare cookies and varions system settings
+ */
+ private function prepare_cookies() {
+ global $CFG, $nomoodlecookie;
+
+ if (!defined('NO_MOODLE_COOKIES')) {
+ if (isset($nomoodlecookie)) {
+ // backwards compatibility only
+ define('NO_MOODLE_COOKIES', $nomoodlecookie);
+ unset($nomoodlecookie);
+ } else {
+ define('NO_MOODLE_COOKIES', false);
+ }
+ }
+
+ if (!isset($CFG->cookiesecure) or strpos($CFG->wwwroot, 'https://') !== 0) {
+ $CFG->cookiesecure = 0;
+ }
+
+ if (!isset($CFG->cookiehttponly)) {
+ $CFG->cookiehttponly = 0;
+ }
+
+ /// Set sessioncookie and sessioncookiepath variable if it isn't already
+ if (!isset($CFG->sessioncookie)) {
+ $CFG->sessioncookie = '';
+ }
+ if (!isset($CFG->sessioncookiepath)) {
+ $CFG->sessioncookiepath = '/';
+ }
+
+ //discard session ID from POST, GET and globals to tighten security,
+ //this session fixation prevention can not be used in cookieless mode
+ if (empty($CFG->usesid)) {
+ unset(${'MoodleSession'.$CFG->sessioncookie});
+ unset($_GET['MoodleSession'.$CFG->sessioncookie]);
+ unset($_POST['MoodleSession'.$CFG->sessioncookie]);
+ }
+ //compatibility hack for Moodle Cron, cookies not deleted, but set to "deleted" - should not be needed with NO_MOODLE_COOKIES in cron.php now
+ if (!empty($_COOKIE['MoodleSession'.$CFG->sessioncookie]) && $_COOKIE['MoodleSession'.$CFG->sessioncookie] == "deleted") {
+ unset($_COOKIE['MoodleSession'.$CFG->sessioncookie]);
+ }
+ if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] == "deleted") {
+ unset($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]);
+ }
+ }
+
+ /**
+ * Inits session storage.
+ */
+ private function init_session_storage() {
+ global $CFG;
+
+ /// Set up session handling
+ if(empty($CFG->respectsessionsettings)) {
+ if (true) { /// File-based sessions
+ // Some distros disable GC by setting probability to 0
+ // overriding the PHP default of 1
+ // (gc_probability is divided by gc_divisor, which defaults to 1000)
+ if (ini_get('session.gc_probability') == 0) {
+ ini_set('session.gc_probability', 1);
+ }
+
+ if (!empty($CFG->sessiontimeout)) {
+ ini_set('session.gc_maxlifetime', $CFG->sessiontimeout);
+ }
+
+ if (!file_exists($CFG->dataroot .'/sessions')) {
+ make_upload_directory('sessions');
+ }
+ ini_set('session.save_path', $CFG->dataroot .'/sessions');
+
+ } else { /// Database sessions
+ // TODO: implement proper database session storage
+ }
+ }
+ }
+
+ /**
+ * Sets a moodle cookie with a weakly encrypted string
+ *
+ * @uses $CFG
+ * @uses DAYSECS
+ * @uses HOURSECS
+ * @param string $thing The string to encrypt and place in a cookie
+ */
+ public static function set_moodle_cookie($thing) {
+ global $CFG;
+
+ if ($thing == 'guest') { // Ignore guest account
+ return;
+ }
+
+ $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
+
+ $days = 60;
+ $seconds = DAYSECS*$days;
+
+ // no need to set secure or http cookie only here - it is not secret
+ setCookie($cookiename, '', time() - HOURSECS, $CFG->sessioncookiepath);
+ setCookie($cookiename, rc4encrypt($thing), time()+$seconds, $CFG->sessioncookiepath);
+ }
+
+ /**
+ * Gets a moodle cookie with a weakly encrypted string
+ *
+ * @uses $CFG
+ * @return string
+ */
+ public static function get_moodle_cookie() {
+ global $CFG;
+
+ $cookiename = 'MOODLEID_'.$CFG->sessioncookie;
+
+ if (empty($_COOKIE[$cookiename])) {
+ return '';
+ } else {
+ $thing = rc4decrypt($_COOKIE[$cookiename]);
+ return ($thing == 'guest') ? '': $thing; // Ignore guest account
+ }
+ }
+
+ /**
+ * Enable cookieless sessions by including $CFG->usesid=true;
+ * in config.php.
+ * Based on code from php manual by Richard at postamble.co.uk
+ * Attempts to use cookies if cookies not present then uses session ids attached to all urls and forms to pass session id from page to page.
+ * If site is open to google, google is given guest access as usual and there are no sessions. No session ids will be attached to urls for googlebot.
+ * This doesn't require trans_sid to be turned on but this is recommended for better performance
+ * you should put :
+ * session.use_trans_sid = 1
+ * in your php.ini file and make sure that you don't have a line like this in your php.ini
+ * session.use_only_cookies = 1
+ * @author Richard at postamble.co.uk and Jamie Pratt
+ * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+ /**
+ * You won't call this function directly. This function is used to process
+ * text buffered by php in an output buffer. All output is run through this function
+ * before it is ouput.
+ * @param string $buffer is the output sent from php
+ * @return string the output sent to the browser
+ */
+ public static function sid_ob_rewrite($buffer){
+ $replacements = array(
+ '/(<\s*(a|link|script|frame|area)\s[^>]*(href|src)\s*=\s*")([^"]*)(")/i',
+ '/(<\s*(a|link|script|frame|area)\s[^>]*(href|src)\s*=\s*\')([^\']*)(\')/i');
+
+ $buffer = preg_replace_callback($replacements, array('moodle_session', 'sid_rewrite_link_tag'), $buffer);
+ $buffer = preg_replace('/<form\s[^>]*>/i',
+ '\0<input type="hidden" name="' . session_name() . '" value="' . session_id() . '"/>', $buffer);
+
+ return $buffer;
+ }
+ /**
+ * You won't call this function directly. This function is used to process
+ * text buffered by php in an output buffer. All output is run through this function
+ * before it is ouput.
+ * This function only processes absolute urls, it is used when we decide that
+ * php is processing other urls itself but needs some help with internal absolute urls still.
+ * @param string $buffer is the output sent from php
+ * @return string the output sent to the browser
+ */
+ public static function sid_ob_rewrite_absolute($buffer){
+ $replacements = array(
+ '/(<\s*(a|link|script|frame|area)\s[^>]*(href|src)\s*=\s*")((?:http|https)[^"]*)(")/i',
+ '/(<\s*(a|link|script|frame|area)\s[^>]*(href|src)\s*=\s*\')((?:http|https)[^\']*)(\')/i');
+
+ $buffer = preg_replace_callback($replacements, array('moodle_session', 'sid_rewrite_link_tag'), $buffer);
+ $buffer = preg_replace('/<form\s[^>]*>/i',
+ '\0<input type="hidden" name="' . session_name() . '" value="' . session_id() . '"/>', $buffer);
+ return $buffer;
+ }
+
+ /**
+ * A function to process link, a and script tags found
+ * by preg_replace_callback in {@link sid_ob_rewrite($buffer)}.
+ */
+ public static function sid_rewrite_link_tag($matches){
+ $url = $matches[4];
+ $url = moodle_session::sid_process_url($url);
+ return $matches[1].$url.$matches[5];
+ }
+
+ /**
+ * You can call this function directly. This function is used to process
+ * urls to add a moodle session id to the url for internal links.
+ * @param string $url is a url
+ * @return string the processed url
+ */
+ public static function sid_process_url($url) {
+ global $CFG;
+
+ if ((preg_match('/^(http|https):/i', $url)) // absolute url
+ && ((stripos($url, $CFG->wwwroot)!==0) && stripos($url, $CFG->httpswwwroot)!==0)) { // and not local one
+ return $url; //don't attach sessid to non local urls
+ }
+ if ($url[0]=='#' || (stripos($url, 'javascript:')===0)) {
+ return $url; //don't attach sessid to anchors
+ }
+ if (strpos($url, session_name())!==FALSE) {
+ return $url; //don't attach sessid to url that already has one sessid
+ }
+ if (strpos($url, "?")===FALSE) {
+ $append = "?".strip_tags(session_name() . '=' . session_id());
+ } else {
+ $append = "&".strip_tags(session_name() . '=' . session_id());
+ }
+ //put sessid before any anchor
+ $p = strpos($url, "#");
+ if ($p!==FALSE){
+ $anch = substr($url, $p);
+ $url = substr($url, 0, $p).$append.$anch ;
+ } else {
+ $url .= $append ;
+ }
+ return $url;
+ }
+
+ /**
+ * Call this function before there has been any output to the browser to
+ * buffer output and add session ids to all internal links.
+ */
+ public static function sid_start_ob(){
+ global $CFG;
+ //don't attach sess id for bots
+
+ if (!empty($_SERVER['HTTP_USER_AGENT'])) {
+ if (!empty($CFG->opentogoogle)) {
+ if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false) {
+ @ini_set('session.use_trans_sid', '0'); // try and turn off trans_sid
+ $CFG->usesid=false;
+ return;
+ }
+ if (strpos($_SERVER['HTTP_USER_AGENT'], 'google.com') !== false) {
+ @ini_set('session.use_trans_sid', '0'); // try and turn off trans_sid
+ $CFG->usesid=false;
+ return;
+ }
+ }
+ if (strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) {
+ @ini_set('session.use_trans_sid', '0'); // try and turn off trans_sid
+ $CFG->usesid=false;
+ return;
+ }
+ }
+
+ @ini_set('session.use_trans_sid', '1'); // try and turn on trans_sid
+
+ if (ini_get('session.use_trans_sid') != 0) {
+ // use trans sid as its available
+ ini_set('url_rewriter.tags', 'a=href,area=href,script=src,link=href,frame=src,form=fakeentry');
+ ob_start(array('moodle_session', 'sid_ob_rewrite_absolute'));
+ } else {
+ //rewrite all links ourselves
+ ob_start(array('moodle_session', 'sid_ob_rewrite'));
+ }
+ }
+}
\ No newline at end of file
projects / moodle.git / commitdiff