1 <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
5 * An open source application development framework for PHP 5.1.6 or newer
8 * @author ExpressionEngine Dev Team
9 * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
10 * @license http://codeigniter.com/user_guide/license.html
11 * @link http://codeigniter.com
16 // ------------------------------------------------------------------------
21 * @package CodeIgniter
22 * @subpackage Libraries
24 * @author ExpressionEngine Dev Team
25 * @link http://codeigniter.com/user_guide/libraries/sessions.html
29 var $sess_encrypt_cookie = FALSE;
30 var $sess_use_database = FALSE;
31 var $sess_table_name = '';
32 var $sess_expiration = 7200;
33 var $sess_expire_on_close = FALSE;
34 var $sess_match_ip = FALSE;
35 var $sess_match_useragent = TRUE;
36 var $sess_cookie_name = 'ci_session';
37 var $cookie_prefix = '';
38 var $cookie_path = '';
39 var $cookie_domain = '';
40 var $cookie_secure = FALSE;
41 var $sess_time_to_update = 300;
42 var $encryption_key = '';
43 var $flashdata_key = 'flash';
44 var $time_reference = 'time';
45 var $gc_probability = 5;
46 var $userdata = array();
53 * The constructor runs the session routines automatically
54 * whenever the class is instantiated.
56 public function __construct($params = array())
58 log_message('debug', "Session Class Initialized");
60 // Set the super object to a local variable for use throughout the class
61 $this->CI =& get_instance();
63 // Set all the session preferences, which can either be set
64 // manually via the $params array above or via the config file
65 foreach (array('sess_encrypt_cookie', 'sess_use_database', 'sess_table_name', 'sess_expiration', 'sess_expire_on_close', 'sess_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'cookie_secure', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key') as $key)
67 $this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key);
70 if ($this->encryption_key == '')
72 show_error('In order to use the Session class you are required to set an encryption key in your config file.');
75 // Load the string helper so we can use the strip_slashes() function
76 $this->CI->load->helper('string');
78 // Do we need encryption? If so, load the encryption class
79 if ($this->sess_encrypt_cookie == TRUE)
81 $this->CI->load->library('encrypt');
84 // Are we using a database? If so, load it
85 if ($this->sess_use_database === TRUE AND $this->sess_table_name != '')
87 $this->CI->load->database();
90 // Set the "now" time. Can either be GMT or server time, based on the
91 // config prefs. We use this to set the "last activity" time
92 $this->now = $this->_get_time();
94 // Set the session length. If the session expiration is
95 // set to zero we'll set the expiration two years from now.
96 if ($this->sess_expiration == 0)
98 $this->sess_expiration = (60*60*24*365*2);
101 // Set the cookie name
102 $this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;
104 // Run the Session routine. If a session doesn't exist we'll
105 // create a new one. If it does, we'll update it.
106 if ( ! $this->sess_read())
108 $this->sess_create();
112 $this->sess_update();
115 // Delete 'old' flashdata (from last request)
116 $this->_flashdata_sweep();
118 // Mark all new flashdata as old (data will be deleted before next request)
119 $this->_flashdata_mark();
121 // Delete expired sessions if necessary
124 log_message('debug', "Session routines successfully run");
127 // --------------------------------------------------------------------
130 * Fetch the current session data if it exists
138 $session = $this->CI->input->cookie($this->sess_cookie_name);
140 // No cookie? Goodbye cruel world!...
141 if ($session === FALSE)
143 log_message('debug', 'A session cookie was not found.');
147 // Decrypt the cookie data
148 if ($this->sess_encrypt_cookie == TRUE)
150 $session = $this->CI->encrypt->decode($session);
154 // encryption was not used, so we need to check the md5 hash
155 $hash = substr($session, strlen($session)-32); // get last 32 chars
156 $session = substr($session, 0, strlen($session)-32);
158 // Does the md5 hash match? This is to prevent manipulation of session data in userspace
159 if ($hash !== md5($session.$this->encryption_key))
161 log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.');
162 $this->sess_destroy();
167 // Unserialize the session array
168 $session = $this->_unserialize($session);
170 // Is the session data we unserialized an array with the correct format?
171 if ( ! is_array($session) OR ! isset($session['session_id']) OR ! isset($session['ip_address']) OR ! isset($session['user_agent']) OR ! isset($session['last_activity']))
173 $this->sess_destroy();
177 // Is the session current?
178 if (($session['last_activity'] + $this->sess_expiration) < $this->now)
180 $this->sess_destroy();
184 // Does the IP Match?
185 if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address())
187 $this->sess_destroy();
191 // Does the User Agent Match?
192 if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 50)))
194 $this->sess_destroy();
198 // Is there a corresponding session in the DB?
199 if ($this->sess_use_database === TRUE)
201 $this->CI->db->where('session_id', $session['session_id']);
203 if ($this->sess_match_ip == TRUE)
205 $this->CI->db->where('ip_address', $session['ip_address']);
208 if ($this->sess_match_useragent == TRUE)
210 $this->CI->db->where('user_agent', $session['user_agent']);
213 $query = $this->CI->db->get($this->sess_table_name);
215 // No result? Kill it!
216 if ($query->num_rows() == 0)
218 $this->sess_destroy();
222 // Is there custom data? If so, add it to the main session array
223 $row = $query->row();
224 if (isset($row->user_data) AND $row->user_data != '')
226 $custom_data = $this->_unserialize($row->user_data);
228 if (is_array($custom_data))
230 foreach ($custom_data as $key => $val)
232 $session[$key] = $val;
239 $this->userdata = $session;
245 // --------------------------------------------------------------------
248 * Write the session data
253 function sess_write()
255 // Are we saving custom data to the DB? If not, all we do is update the cookie
256 if ($this->sess_use_database === FALSE)
258 $this->_set_cookie();
262 // set the custom userdata, the session data we will set in a second
263 $custom_userdata = $this->userdata;
264 $cookie_userdata = array();
266 // Before continuing, we need to determine if there is any custom data to deal with.
267 // Let's determine this by removing the default indexes to see if there's anything left in the array
268 // and set the session data while we're at it
269 foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
271 unset($custom_userdata[$val]);
272 $cookie_userdata[$val] = $this->userdata[$val];
275 // Did we find any custom data? If not, we turn the empty array into a string
276 // since there's no reason to serialize and store an empty array in the DB
277 if (count($custom_userdata) === 0)
279 $custom_userdata = '';
283 // Serialize the custom data array so we can store it
284 $custom_userdata = $this->_serialize($custom_userdata);
287 // Run the update query
288 $this->CI->db->where('session_id', $this->userdata['session_id']);
289 $this->CI->db->update($this->sess_table_name, array('last_activity' => $this->userdata['last_activity'], 'user_data' => $custom_userdata));
291 // Write the cookie. Notice that we manually pass the cookie data array to the
292 // _set_cookie() function. Normally that function will store $this->userdata, but
293 // in this case that array contains custom data, which we do not want in the cookie.
294 $this->_set_cookie($cookie_userdata);
297 // --------------------------------------------------------------------
300 * Create a new session
305 function sess_create()
308 while (strlen($sessid) < 32)
310 $sessid .= mt_rand(0, mt_getrandmax());
313 // To make the session ID even more secure we'll combine it with the user's IP
314 $sessid .= $this->CI->input->ip_address();
316 $this->userdata = array(
317 'session_id' => md5(uniqid($sessid, TRUE)),
318 'ip_address' => $this->CI->input->ip_address(),
319 'user_agent' => substr($this->CI->input->user_agent(), 0, 50),
320 'last_activity' => $this->now
324 // Save the data to the DB if needed
325 if ($this->sess_use_database === TRUE)
327 $this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata));
331 $this->_set_cookie();
334 // --------------------------------------------------------------------
337 * Update an existing session
342 function sess_update()
344 // We only update the session every five minutes by default
345 if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
350 // Save the old session id so we know which record to
351 // update in the database if we need it
352 $old_sessid = $this->userdata['session_id'];
354 while (strlen($new_sessid) < 32)
356 $new_sessid .= mt_rand(0, mt_getrandmax());
359 // To make the session ID even more secure we'll combine it with the user's IP
360 $new_sessid .= $this->CI->input->ip_address();
362 // Turn it into a hash
363 $new_sessid = md5(uniqid($new_sessid, TRUE));
365 // Update the session data in the session data array
366 $this->userdata['session_id'] = $new_sessid;
367 $this->userdata['last_activity'] = $this->now;
369 // _set_cookie() will handle this for us if we aren't using database sessions
370 // by pushing all userdata to the cookie.
373 // Update the session ID and last_activity field in the DB if needed
374 if ($this->sess_use_database === TRUE)
376 // set cookie explicitly to only have our session data
377 $cookie_data = array();
378 foreach (array('session_id','ip_address','user_agent','last_activity') as $val)
380 $cookie_data[$val] = $this->userdata[$val];
383 $this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'session_id' => $new_sessid), array('session_id' => $old_sessid)));
387 $this->_set_cookie($cookie_data);
390 // --------------------------------------------------------------------
393 * Destroy the current session
398 function sess_destroy()
400 // Kill the session DB row
401 if ($this->sess_use_database === TRUE AND isset($this->userdata['session_id']))
403 $this->CI->db->where('session_id', $this->userdata['session_id']);
404 $this->CI->db->delete($this->sess_table_name);
409 $this->sess_cookie_name,
410 addslashes(serialize(array())),
411 ($this->now - 31500000),
413 $this->cookie_domain,
418 // --------------------------------------------------------------------
421 * Fetch a specific item from the session array
427 function userdata($item)
429 return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item];
432 // --------------------------------------------------------------------
435 * Fetch all session data
440 function all_userdata()
442 return ( ! isset($this->userdata)) ? FALSE : $this->userdata;
445 // --------------------------------------------------------------------
448 * Add or change data in the "userdata" array
455 function set_userdata($newdata = array(), $newval = '')
457 if (is_string($newdata))
459 $newdata = array($newdata => $newval);
462 if (count($newdata) > 0)
464 foreach ($newdata as $key => $val)
466 $this->userdata[$key] = $val;
473 // --------------------------------------------------------------------
476 * Delete a session variable from the "userdata" array
481 function unset_userdata($newdata = array())
483 if (is_string($newdata))
485 $newdata = array($newdata => '');
488 if (count($newdata) > 0)
490 foreach ($newdata as $key => $val)
492 unset($this->userdata[$key]);
499 // ------------------------------------------------------------------------
502 * Add or change flashdata, only available
503 * until the next request
510 function set_flashdata($newdata = array(), $newval = '')
512 if (is_string($newdata))
514 $newdata = array($newdata => $newval);
517 if (count($newdata) > 0)
519 foreach ($newdata as $key => $val)
521 $flashdata_key = $this->flashdata_key.':new:'.$key;
522 $this->set_userdata($flashdata_key, $val);
527 // ------------------------------------------------------------------------
530 * Keeps existing flashdata available to next request.
536 function keep_flashdata($key)
538 // 'old' flashdata gets removed. Here we mark all
539 // flashdata as 'new' to preserve it from _flashdata_sweep()
540 // Note the function will return FALSE if the $key
541 // provided cannot be found
542 $old_flashdata_key = $this->flashdata_key.':old:'.$key;
543 $value = $this->userdata($old_flashdata_key);
545 $new_flashdata_key = $this->flashdata_key.':new:'.$key;
546 $this->set_userdata($new_flashdata_key, $value);
549 // ------------------------------------------------------------------------
552 * Fetch a specific flashdata item from the session array
558 function flashdata($key)
560 $flashdata_key = $this->flashdata_key.':old:'.$key;
561 return $this->userdata($flashdata_key);
564 // ------------------------------------------------------------------------
567 * Identifies flashdata as 'old' for removal
568 * when _flashdata_sweep() runs.
573 function _flashdata_mark()
575 $userdata = $this->all_userdata();
576 foreach ($userdata as $name => $value)
578 $parts = explode(':new:', $name);
579 if (is_array($parts) && count($parts) === 2)
581 $new_name = $this->flashdata_key.':old:'.$parts[1];
582 $this->set_userdata($new_name, $value);
583 $this->unset_userdata($name);
588 // ------------------------------------------------------------------------
591 * Removes all flashdata marked as 'old'
597 function _flashdata_sweep()
599 $userdata = $this->all_userdata();
600 foreach ($userdata as $key => $value)
602 if (strpos($key, ':old:'))
604 $this->unset_userdata($key);
610 // --------------------------------------------------------------------
620 if (strtolower($this->time_reference) == 'gmt')
623 $time = mktime(gmdate("H", $now), gmdate("i", $now), gmdate("s", $now), gmdate("m", $now), gmdate("d", $now), gmdate("Y", $now));
633 // --------------------------------------------------------------------
636 * Write the session cookie
641 function _set_cookie($cookie_data = NULL)
643 if (is_null($cookie_data))
645 $cookie_data = $this->userdata;
648 // Serialize the userdata for the cookie
649 $cookie_data = $this->_serialize($cookie_data);
651 if ($this->sess_encrypt_cookie == TRUE)
653 $cookie_data = $this->CI->encrypt->encode($cookie_data);
657 // if encryption is not used, we provide an md5 hash to prevent userside tampering
658 $cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key);
661 $expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();
665 $this->sess_cookie_name,
669 $this->cookie_domain,
674 // --------------------------------------------------------------------
679 * This function first converts any slashes found in the array to a temporary
680 * marker, so when it gets unserialized the slashes will be preserved
686 function _serialize($data)
690 foreach ($data as $key => $val)
694 $data[$key] = str_replace('\\', '{{slash}}', $val);
700 if (is_string($data))
702 $data = str_replace('\\', '{{slash}}', $data);
706 return serialize($data);
709 // --------------------------------------------------------------------
714 * This function unserializes a data string, then converts any
715 * temporary slash markers back to actual slashes
721 function _unserialize($data)
723 $data = @unserialize(strip_slashes($data));
727 foreach ($data as $key => $val)
731 $data[$key] = str_replace('{{slash}}', '\\', $val);
738 return (is_string($data)) ? str_replace('{{slash}}', '\\', $data) : $data;
741 // --------------------------------------------------------------------
746 * This deletes expired session rows from database
747 * if the probability percentage is met
754 if ($this->sess_use_database != TRUE)
760 if ((rand() % 100) < $this->gc_probability)
762 $expire = $this->now - $this->sess_expiration;
764 $this->CI->db->where("last_activity < {$expire}");
765 $this->CI->db->delete($this->sess_table_name);
767 log_message('debug', 'Session garbage collection performed.');
775 /* End of file Session.php */
776 /* Location: ./system/libraries/Session.php */