CodeIgniter Session Failing only in China
I also experienced alot of issues on CI sessions and ended up using this library for sessions ever since i am a happy man <?php/** The EckoTools Session Library @package The EckoTools Session Library @category Libraries @author Hartmut König (h.koenig@eckotools.com) @link http://www.okidoe.de @version 1.0.2 @copyright Hartmut König 2009 A class to handle sessions by using a mySQL database for session related data storage providing better security then the default session handler used by PHP with added protection against Session Hijacking & Fixation including the flashdata-Feature of CI. It don't use Browser or IP to identify the user. Instead I generate a fingerprint of different seldom changing data (@link _generate_fingerprint) To prevent session hijacking, don't forget to use the {@link regenerate_id} method whenever you do a privilege change in your application -- -- MYSQL: Table structure for table `ci_sessions` --CREATE TABLE `ci_sessions` ( `session_id` varchar(32) NOT NULL default '', `fingerprint` varchar(32) NOT NULL default '', `session_data` blob NOT NULL, `session_expire` int(11) NOT NULL default '0', PRIMARY KEY (`session_id`)) ENGINE=MyISAM DEFAULT CHARSET=latin1; This class is an adaptation between the original CI Sessions, Native Sessions and my own coding*/error_reporting(E_ALL);class CI_Session{ /** * Constructor of class * * Initializes the class and starts a new session * * There is no need to call start_session() after instantiating this class * * $gc_maxlifetime (optional) the number of seconds after which data will be seen as 'garbage' and * cleaned up on the next run of the gc (garbage collection) routine * * Default is specified in php.ini file * * $gc_probability (optional) used in conjunction with gc_divisor, is used to manage probability that * the gc routine is started. the probability is expressed by the formula * * probability = $gc_probability / $gc_divisor * * So if $gc_probability is 1 and $gc_divisor is 100 means that there is * a 1% chance the the gc routine will be called on each request * * Default is specified in php.ini file * * $gc_divisor (optional) used in conjunction with gc_probability, is used to manage probability * that the gc routine is started. the probability is expressed by the formula * * probability = $gc_probability / $gc_divisor * * So if $gc_probability is 1 and $gc_divisor is 100 means that there is * a 1% chance the the gc routine will be called on each request * * Default is specified in php.ini file * * $security_code (optional) the value of this argument is appended to the fingerprint before * creating the md5 hash out of it. this way we'll try to prevent fingerprint * spoofing * * Default is 'LeouOeEkKpvSnD-YCHd5ogt3y' * * $table_name (optional) You can change the name of that table by setting this property * * Default is 'ci_sessions' * * @return void */ function CI_Session( $security_code="LeouOeEkKpvSnD-YCHd5ogt3y",$table_name="ci_sessions" ) { //-- CI Config $this->CI = & get_instance(); $this->flashdata_key = 'flash'; // prefix for "flash" variables (eg. flash:new:message) $table_name = $this->CI->config->item('sess_table_name'); $gc_maxlifetime = $this->CI->config->item('sess_expiration'); $gc_probability = $this->CI->config->item('sess_gc_probability'); $gc_divisor = $this->CI->config->item('sess_gc_divisor'); $sess_name = $this->CI->config->item('sess_cookie_name'); // if $gc_maxlifetime is specified and is an integer number (!empty($gc_maxlifetime) && is_integer($gc_maxlifetime)) ? @ini_set('session.gc_maxlifetime', $gc_maxlifetime) : false; // if $gc_probability is specified and is an integer number (!empty($gc_probability) && is_integer($gc_probability)) ? @ini_set('session.gc_probability', $gc_probability) : false; // if $gc_divisor is specified and is an integer number (!empty($gc_divisor) && is_integer($gc_divisor)) ? @ini_set('session.gc_divisor', $gc_divisor) : false; (!empty($sess_name)) ? @ini_set('session.name', $sess_name) : false; // get session lifetime $this->sessionLifetime = ini_get("session.gc_maxlifetime"); // we'll use this later in order to prevent fingerprint spoofing $this->securityCode = $security_code; $this->tableName = $table_name; // register the new handler session_set_save_handler( array(&$this, '_open'), array(&$this, '_close'), array(&$this, '_read'), array(&$this, '_write'), array(&$this, '_destroy'), array(&$this, '_gc') ); register_shutdown_function('session_write_close'); // start the session session_start(); // Delete 'old' flashdata (from last request) $this->_flashdata_sweep(); // Mark all new flashdata as old (data will be deleted before next request) $this->_flashdata_mark(); } /** * Reads given session attribute value * * @return integer sessionvalue */ function userdata($item) { //added for backward-compatibility if($item == 'session_id') { return session_id(); } if(isset($_SESSION[$item])) { return($_SESSION[$item]); } return(false); } /** * Fetch all session data * * @access public * @return mixed */ function all_userdata() { return ( ! isset($_SESSION)) ? FALSE : $_SESSION; } /** * Sets session attributes to the given values * * @return void */ function set_userdata($newdata = array(), $newval = '') { (is_string($newdata)) ? $newdata = array($newdata => $newval) : false; if(count($newdata) > 0) { foreach($newdata as $key => $val) { $_SESSION[$key] = $val; } } } /** * Erases given session attributes * * @return void */ function unset_userdata($newdata = array()) { (is_string($newdata)) ? $newdata = array($newdata => '') : false; if(count($newdata) > 0) { foreach ($newdata as $key => $val) { unset($_SESSION[$key]); } } } /** * Deletes all data related to the session * @return void */ function sess_destroy() { $this->regenerate_id(); session_unset(); session_destroy(); } /** * Regenerates the session id. * * <b>Call this method whenever you do a privilege change!</b> * * @return void */ function regenerate_id() { // saves the old session's id $oldSessionID = session_id(); // regenerates the id // this function will create a new session, with a new id and containing the data from the old session // but will not delete the old session session_regenerate_id(); // because the session_regenerate_id() function does not delete the old session, // we have to delete it manually $this->_destroy($oldSessionID); } /** * Add or change flashdata, only available * until the next request * * @access public * @param mixed * @param string * @return void */ function set_flashdata($newdata = array(), $newval = '') { if (is_string($newdata)) { $newdata = array($newdata => $newval); } if (count($newdata) > 0) { foreach ($newdata as $key => $val) { $flashdata_key = $this->flashdata_key.':new:'.$key; $this->set_userdata($flashdata_key, $val); } } } // ------------------------------------------------------------------------ /** * Keeps existing flashdata available to next request. * * @access public * @param string * @return void */ function keep_flashdata($key) { // 'old' flashdata gets removed. Here we mark all // flashdata as 'new' to preserve it from _flashdata_sweep() // Note the function will return FALSE if the $key // provided cannot be found $old_flashdata_key = $this->flashdata_key.':old:'.$key; $value = $this->userdata($old_flashdata_key); $new_flashdata_key = $this->flashdata_key.':new:'.$key; $this->set_userdata($new_flashdata_key, $value); } // ------------------------------------------------------------------------ /** * Fetch a specific flashdata item from the session array * * @access public * @param string * @return string */ function flashdata($key) { $flashdata_key = $this->flashdata_key.':old:'.$key; return $this->userdata($flashdata_key); } // ------------------------------------------------------------------------ /** * Identifies flashdata as 'old' for removal * when _flashdata_sweep() runs. * * @access private * @return void */ function _flashdata_mark() { $userdata = $this->all_userdata(); foreach ($userdata as $name => $value) { $parts = explode(':new:', $name); if (is_array($parts) && count($parts) === 2) { $new_name = $this->flashdata_key.':old:'.$parts[1]; $this->set_userdata($new_name, $value); $this->unset_userdata($name); } } } // ------------------------------------------------------------------------ /** * Removes all flashdata marked as 'old' * * @access private * @return void */ function _flashdata_sweep() { $userdata = $this->all_userdata(); foreach($userdata as $key => $value) { if (strpos($key, ':old:')) { $this->unset_userdata($key); } } } /** * Get the number of online users * * @return integer number of users currently online */ function get_users_online() { // counts the rows from the database $query = $this->CI->db->query("SELECT COUNT(session_id) as count FROM ".$this->tableName); $result = $query->row(); // return the number of found rows return $result->count; } /** * Generates key as protection against Session Hijacking & Fixation. * @access private * @return string */ function _generate_fingerprint() { //-- We don't use the ip-adress, because this is a subject to change in most cases (proxies etc.) $list = array('HTTP_ACCEPT_CHARSET', 'HTTP_ACCEPT_ENCODING', 'HTTP_ACCEPT_LANGUAGE', 'HTTP_USER_AGENT'); $key = array($this->securityCode); foreach($list as $item) { $key[] = $this->CI->input->server($item); } return md5(implode("\0", $key)); } /** * Custom open() function * * @access private */ function _open($save_path, $session_name) { return(true); } /** * Custom close() function * * @access private */ function _close() { return(true); } /** * Custom read() function * * @access private */ function _read($session_id) { // reads session data associated with the session id // but only // - if the fingerprint is the same as the one who had previously written to this session AND // - if session has not expired $result = $this->CI->db->query("SELECT session_data ". "FROM ".$this->tableName." ". "WHERE session_id = ".$this->CI->db->escape($session_id)." ". "AND fingerprint = ".$this->CI->db->escape($this->_generate_fingerprint())." ". "AND session_expire > '".time()."' LIMIT 1"); // if anything was found if($result->num_rows() > 0) { // return found data $fields = $result->row(); // Unserialization - PHP handles this automatically return $fields->session_data; } // if there was an error return an empty string - this HAS to be an empty string return(""); } /** * Custom write() function * * @access private */ function _write($session_id, $session_data) { // insert OR update session's data - this is how it works: // first it tries to insert a new row in the database BUT if session_id is already in the database then just // update session_data and session_expire for that specific session_id // read more here http://dev.mysql.com/doc/refman/4.1/en/insert-on-duplicate.html $result = $this->CI->db->query( "INSERT INTO ".$this->tableName." (". "session_id,". "fingerprint,". "session_data,". "session_expire". ") VALUES (". $this->CI->db->escape($session_id).",". $this->CI->db->escape($this->_generate_fingerprint()).",". $this->CI->db->escape($session_data).",". $this->CI->db->escape(time() + $this->sessionLifetime). ")". "ON DUPLICATE KEY UPDATE ". "session_data = ".$this->CI->db->escape($session_data).",". "session_expire = ".$this->CI->db->escape(time() + $this->sessionLifetime)); // note that after this type of queries, mysql_affected_rows() returns // - 1 if the row was inserted // - 2 if the row was updated switch($this->CI->db->affected_rows()) { // if the row was inserted case 1: return(""); break; // if the row was updated case 2: return(true); break; // if something went wrong, return false default: return(false); break; } } /** * Custom destroy() function * * @access private */ function _destroy($session_id) { // deletes the current session id from the database $result = $this->CI->db->query("DELETE FROM ".$this->tableName." ". "WHERE session_id = ".$this->CI->db->escape($session_id)); // if anything happened if($this->CI->db->affected_rows()) { return(true); } // if something went wrong, return false return(false); } /** * Custom gc() function (garbage collector) * * @access private */function _gc($maxlifetime) { // it deletes expired sessions from database $result = $this->CI->db->query("DELETE FROM ".$this->tableName." ". "WHERE session_expire < ".$this->CI->db->escape(time() - $maxlifetime)); }}?>
Though there are a large number of possible causes (CodeIgniter sessions are notorious for being glitchy) this is likely a timezone issue, not a character issue.
To fix the problem—assuming you do not need a low timeout—increase the session timeout!
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