summaryrefslogtreecommitdiffstats
path: root/system/libraries/Session/drivers/Session_cookie.php
blob: 9392a4dbe3ebcd3f49502e14bcc9fa17f64ef87a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the files license.txt / license.rst.  It is
 * also available through the world wide web at this URL:
 * http://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Cookie-based session management driver
 *
 * This is the classic CI_Session functionality, as written by EllisLab, abstracted out to a driver.
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Sessions
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/sessions.html
 */
class CI_Session_cookie extends CI_Session_driver {

	/**
	 * Whether to encrypt the session cookie
	 *
	 * @var bool
	 */
	public $sess_encrypt_cookie		= FALSE;

	/**
	 * Whether to use to the database for session storage
	 *
	 * @var bool
	 */
	public $sess_use_database		= FALSE;

	/**
	 * Name of the database table in which to store sessions
	 *
	 * @var string
	 */
	public $sess_table_name			= '';

	/**
	 * Length of time (in seconds) for sessions to expire
	 *
	 * @var int
	 */
	public $sess_expiration			= 7200;

	/**
	 * Whether to kill session on close of browser window
	 *
	 * @var bool
	 */
	public $sess_expire_on_close	= FALSE;

	/**
	 * Whether to match session on ip address
	 *
	 * @var bool
	 */
	public $sess_match_ip			= FALSE;

	/**
	 * Whether to match session on user-agent
	 *
	 * @var bool
	 */
	public $sess_match_useragent	= TRUE;

	/**
	 * Name of session cookie
	 *
	 * @var string
	 */
	public $sess_cookie_name		= 'ci_session';

	/**
	 * Session cookie prefix
	 *
	 * @var string
	 */
	public $cookie_prefix			= '';

	/**
	 * Session cookie path
	 *
	 * @var string
	 */
	public $cookie_path				= '';

	/**
	 * Session cookie domain
	 *
	 * @var string
	 */
	public $cookie_domain			= '';

	/**
	 * Whether to set the cookie only on HTTPS connections
	 *
	 * @var bool
	 */
	public $cookie_secure			= FALSE;

	/**
	 * Whether cookie should be allowed only to be sent by the server
	 *
	 * @var bool
	 */
	public $cookie_httponly 		= FALSE;

	/**
	 * Interval at which to update session
	 *
	 * @var int
	 */
	public $sess_time_to_update		= 300;

	/**
	 * Key with which to encrypt the session cookie
	 *
	 * @var string
	 */
	public $encryption_key			= '';

	/**
	 * Timezone to use for the current time
	 *
	 * @var string
	 */
	public $time_reference			= 'local';

	/**
	 * Session data
	 *
	 * @var array
	 */
	public $userdata				= array();

	/**
	 * Current time
	 *
	 * @var int
	 */
	public $now;

	/**
	 * Default userdata keys
	 *
	 * @var	array
	 */
	protected $defaults = array(
		'session_id' => NULL,
		'ip_address' => NULL,
		'user_agent' => NULL,
		'last_activity' => NULL
	);

	/**
	 * Data needs DB update flag
	 *
	 * @var	bool
	 */
	protected $data_dirty = FALSE;

	/**
	 * Initialize session driver object
	 *
	 * @return	void
	 */
	protected function initialize()
	{
		// Set all the session preferences, which can either be set
		// manually via the $params array or via the config file
		$prefs = 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',
			'cookie_httponly',
			'sess_time_to_update',
			'time_reference',
			'cookie_prefix',
			'encryption_key'
		);

		foreach ($prefs as $key)
		{
			$this->$key = isset($this->_parent->params[$key])
				? $this->_parent->params[$key]
				: $this->CI->config->item($key);
		}

		if (empty($this->encryption_key))
		{
			show_error('In order to use the Cookie Session driver you are required to set an encryption key in your config file.');
		}

		// Do we need encryption? If so, load the encryption class
		if ($this->sess_encrypt_cookie === TRUE)
		{
			$this->CI->load->library('encrypt');
		}

		// Check for database
		if ($this->sess_use_database === TRUE && $this->sess_table_name !== '')
		{
			// Load database driver
			$this->CI->load->database();

			// Register shutdown function
			register_shutdown_function(array($this, '_update_db'));
		}

		// Set the "now" time. Can either be GMT or server time, based on the config prefs.
		// We use this to set the "last activity" time
		$this->now = $this->_get_time();

		// Set the session length. If the session expiration is
		// set to zero we'll set the expiration two years from now.
		if ($this->sess_expiration === 0)
		{
			$this->sess_expiration = (60*60*24*365*2);
		}

		// Set the cookie name
		$this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name;

		// Run the Session routine. If a session doesn't exist we'll
		// create a new one. If it does, we'll update it.
		if ( ! $this->_sess_read())
		{
			$this->_sess_create();
		}
		else
		{
			$this->_sess_update();
		}

		// Delete expired sessions if necessary
		$this->_sess_gc();
	}

	// ------------------------------------------------------------------------

	/**
	 * Write the session data
	 *
	 * @return	void
	 */
	public function sess_save()
	{
		// Check for database
		if ($this->sess_use_database === TRUE)
		{
			// Mark custom data as dirty so we know to update the DB
			$this->data_dirty = TRUE;
		}

		// Write the cookie
		$this->_set_cookie();
	}

	// ------------------------------------------------------------------------

	/**
	 * Destroy the current session
	 *
	 * @return	void
	 */
	public function sess_destroy()
	{
		// Kill the session DB row
		if ($this->sess_use_database === TRUE && isset($this->userdata['session_id']))
		{
			$this->CI->db->delete($this->sess_table_name, array('session_id' => $this->userdata['session_id']));
			$this->data_dirty = FALSE;
		}

		// Kill the cookie
		$this->_setcookie($this->sess_cookie_name, '', ($this->now - 31500000),
			$this->cookie_path, $this->cookie_domain, 0);

		// Kill session data
		$this->userdata = array();
	}

	// ------------------------------------------------------------------------

	/**
	 * Regenerate the current session
	 *
	 * Regenerate the session id
	 *
	 * @param	bool	Destroy session data flag (default: false)
	 * @return	void
	 */
	public function sess_regenerate($destroy = FALSE)
	{
		// Check destroy flag
		if ($destroy)
		{
			// Destroy old session and create new one
			$this->sess_destroy();
			$this->_sess_create();
		}
		else
		{
			// Just force an update to recreate the id
			$this->_sess_update(TRUE);
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Get a reference to user data array
	 *
	 * @return	array	Reference to userdata
	 */
	public function &get_userdata()
	{
		return $this->userdata;
	}

	// ------------------------------------------------------------------------

	/**
	 * Fetch the current session data if it exists
	 *
	 * @return	bool
	 */
	protected function _sess_read()
	{
		// Fetch the cookie
		$session = $this->CI->input->cookie($this->sess_cookie_name);

		// No cookie? Goodbye cruel world!...
		if ($session === NULL)
		{
			log_message('debug', 'A session cookie was not found.');
			return FALSE;
		}

		$len = strlen($session) - 40;

		if ($len < 0)
		{
			log_message('debug', 'The session cookie was not signed.');
			return FALSE;
		}

		// Check cookie authentication
		$hmac	 = substr($session, $len);
		$session = substr($session, 0, $len);

		if ($hmac !== hash_hmac('sha1', $session, $this->encryption_key))
		{
			log_message('error', 'The session cookie data did not match what was expected.');
			$this->sess_destroy();
			return FALSE;
		}

		// Check for encryption
		if ($this->sess_encrypt_cookie === TRUE)
		{
			// Decrypt the cookie data
			$session = $this->CI->encrypt->decode($session);
		}

		// Unserialize the session array
		$session = $this->_unserialize($session);

		// Is the session data we unserialized an array with the correct format?
		if ( ! is_array($session) OR ! isset($session['session_id'], $session['ip_address'], $session['user_agent'], $session['last_activity']))
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Is the session current?
		if (($session['last_activity'] + $this->sess_expiration) < $this->now OR $session['last_activity'] > $this->now)
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Does the IP match?
		if ($this->sess_match_ip === TRUE && $session['ip_address'] !== $this->CI->input->ip_address())
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Does the User Agent Match?
		if ($this->sess_match_useragent === TRUE &&
			trim($session['user_agent']) !== trim(substr($this->CI->input->user_agent(), 0, 120)))
		{
			$this->sess_destroy();
			return FALSE;
		}

		// Is there a corresponding session in the DB?
		if ($this->sess_use_database === TRUE)
		{
			$this->CI->db->where('session_id', $session['session_id']);

			if ($this->sess_match_ip === TRUE)
			{
				$this->CI->db->where('ip_address', $session['ip_address']);
			}

			if ($this->sess_match_useragent === TRUE)
			{
				$this->CI->db->where('user_agent', $session['user_agent']);
			}

			// Is caching in effect? Turn it off
			$db_cache = $this->CI->db->cache_on;
			$this->CI->db->cache_off();

			$query = $this->CI->db->limit(1)->get($this->sess_table_name);

			// Was caching in effect?
			if ($db_cache)
			{
				// Turn it back on
				$this->CI->db->cache_on();
			}

			// No result? Kill it!
			if (empty($query) OR $query->num_rows() === 0)
			{
				$this->sess_destroy();
				return FALSE;
			}

			// Is there custom data? If so, add it to the main session array
			$row = $query->row();
			if ( ! empty($row->user_data))
			{
				$custom_data = $this->_unserialize($row->user_data);

				if (is_array($custom_data))
				{
					$session = $session + $custom_data;
				}
			}
		}

		// Session is valid!
		$this->userdata = $session;
		return TRUE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Create a new session
	 *
	 * @return	void
	 */
	protected function _sess_create()
	{
		// Initialize userdata
		$this->userdata = array(
			'session_id'	=> $this->_make_sess_id(),
			'ip_address'	=> $this->CI->input->ip_address(),
			'user_agent'	=> substr($this->CI->input->user_agent(), 0, 120),
			'last_activity'	=> $this->now,
		);

		// Check for database
		if ($this->sess_use_database === TRUE)
		{
			// Add empty user_data field and save the data to the DB
			$this->CI->db->set('user_data', '')->insert($this->sess_table_name, $this->userdata);
		}

		// Write the cookie
		$this->_set_cookie();
	}

	// ------------------------------------------------------------------------

	/**
	 * Update an existing session
	 *
	 * @param	bool	Force update flag (default: false)
	 * @return	void
	 */
	protected function _sess_update($force = FALSE)
	{
		// We only update the session every five minutes by default (unless forced)
		if ( ! $force && ($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now)
		{
			return;
		}

		// Update last activity to now
		$this->userdata['last_activity'] = $this->now;

		// Save the old session id so we know which DB record to update
		$old_sessid = $this->userdata['session_id'];

		// Changing the session ID during an AJAX call causes problems
		if ( ! $this->CI->input->is_ajax_request())
		{
			// Get new id
			$this->userdata['session_id'] = $this->_make_sess_id();
		}

		// Check for database
		if ($this->sess_use_database === TRUE)
		{
			$this->CI->db->where('session_id', $old_sessid);

			if ($this->sess_match_ip === TRUE)
			{
				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
			}

			if ($this->sess_match_useragent === TRUE)
			{
				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
			}

			// Update the session ID and last_activity field in the DB
			$this->CI->db->update($this->sess_table_name,
				array(
					'last_activity' => $this->now,
					'session_id' => $this->userdata['session_id']
				)
			);
		}

		// Write the cookie
		$this->_set_cookie();
	}

	// ------------------------------------------------------------------------

	/**
	 * Update database with current data
	 *
	 * This gets called from the shutdown function and also
	 * registered with PHP to run at the end of the request
	 * so it's guaranteed to update even when a fatal error
	 * occurs. The first call makes the update and clears the
	 * dirty flag so it won't happen twice.
	 *
	 * @return	void
	 */
	public function _update_db()
	{
		// Check for database and dirty flag and unsaved
		if ($this->sess_use_database === TRUE && $this->data_dirty === TRUE)
		{
			// Set up activity and data fields to be set
			// If we don't find custom data, user_data will remain an empty string
			$set = array(
				'last_activity' => $this->userdata['last_activity'],
				'user_data' => ''
			);

			// Get the custom userdata, leaving out the defaults
			// (which get stored in the cookie)
			$userdata = array_diff_key($this->userdata, $this->defaults);

			// Did we find any custom data?
			if ( ! empty($userdata))
			{
				// Serialize the custom data array so we can store it
				$set['user_data'] = $this->_serialize($userdata);
			}

			// Run the update query
			// Any time we change the session id, it gets updated immediately,
			// so our where clause below is always safe
			$this->CI->db->where('session_id', $this->userdata['session_id']);

			if ($this->sess_match_ip === TRUE)
			{
				$this->CI->db->where('ip_address', $this->CI->input->ip_address());
			}

			if ($this->sess_match_useragent === TRUE)
			{
				$this->CI->db->where('user_agent', trim(substr($this->CI->input->user_agent(), 0, 120)));
			}

			$this->CI->db->update($this->sess_table_name, $set);

			// Clear dirty flag to prevent double updates
			$this->data_dirty = FALSE;

			log_message('debug', 'CI_Session Data Saved To DB');
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Generate a new session id
	 *
	 * @return	string	Hashed session id
	 */
	protected function _make_sess_id()
	{
		$new_sessid = '';
		do
		{
			$new_sessid .= mt_rand(0, mt_getrandmax());
		}
		while (strlen($new_sessid) < 32);

		// To make the session ID even more secure we'll combine it with the user's IP
		$new_sessid .= $this->CI->input->ip_address();

		// Turn it into a hash and return
		return md5(uniqid($new_sessid, TRUE));
	}

	// ------------------------------------------------------------------------

	/**
	 * Get the "now" time
	 *
	 * @return	int	 Time
	 */
	protected function _get_time()
	{
		if ($this->time_reference === 'local' OR $this->time_reference === date_default_timezone_get())
		{
			return time();
		}

		$datetime = new DateTime('now', new DateTimeZone($this->time_reference));
		sscanf($datetime->format('j-n-Y G:i:s'), '%d-%d-%d %d:%d:%d', $day, $month, $year, $hour, $minute, $second);

		return mktime($hour, $minute, $second, $month, $day, $year);
	}

	// ------------------------------------------------------------------------

	/**
	 * Write the session cookie
	 *
	 * @return	void
	 */
	protected function _set_cookie()
	{
		// Get userdata (only defaults if database)
		$cookie_data = ($this->sess_use_database === TRUE)
				? array_intersect_key($this->userdata, $this->defaults)
				: $this->userdata;

		// Serialize the userdata for the cookie
		$cookie_data = $this->_serialize($cookie_data);

		if ($this->sess_encrypt_cookie === TRUE)
		{
			$cookie_data = $this->CI->encrypt->encode($cookie_data);
		}

		// Require message authentication
		$cookie_data .= hash_hmac('sha1', $cookie_data, $this->encryption_key);

		$expire = ($this->sess_expire_on_close === TRUE) ? 0 : $this->sess_expiration + time();

		// Set the cookie
		$this->_setcookie($this->sess_cookie_name, $cookie_data, $expire, $this->cookie_path, $this->cookie_domain,
			$this->cookie_secure, $this->cookie_httponly);
	}

	// ------------------------------------------------------------------------

	/**
	 * Set a cookie with the system
	 *
	 * This abstraction of the setcookie call allows overriding for unit testing
	 *
	 * @param	string	Cookie name
	 * @param	string	Cookie value
	 * @param	int	Expiration time
	 * @param	string	Cookie path
	 * @param	string	Cookie domain
	 * @param	bool	Secure connection flag
	 * @param	bool	HTTP protocol only flag
	 * @return	void
	 */
	protected function _setcookie($name, $value = '', $expire = 0, $path = '', $domain = '', $secure = FALSE, $httponly = FALSE)
	{
		setcookie($name, $value, $expire, $path, $domain, $secure, $httponly);
	}

	// ------------------------------------------------------------------------

	/**
	 * Serialize an array
	 *
	 * This function first converts any slashes found in the array to a temporary
	 * marker, so when it gets unserialized the slashes will be preserved
	 *
	 * @param	mixed	Data to serialize
	 * @return	string	Serialized data
	 */
	protected function _serialize($data)
	{
		if (is_array($data))
		{
			array_walk_recursive($data, array(&$this, '_escape_slashes'));
		}
		elseif (is_string($data))
		{
			$data = str_replace('\\', '{{slash}}', $data);
		}

		return serialize($data);
	}

	// ------------------------------------------------------------------------

	/**
	 * Escape slashes
	 *
	 * This function converts any slashes found into a temporary marker
	 *
	 * @param	string	Value
	 * @param	string	Key
	 * @return	void
	 */
	protected function _escape_slashes(&$val, $key)
	{
		if (is_string($val))
		{
			$val = str_replace('\\', '{{slash}}', $val);
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Unserialize
	 *
	 * This function unserializes a data string, then converts any
	 * temporary slash markers back to actual slashes
	 *
	 * @param	mixed	Data to unserialize
	 * @return	mixed	Unserialized data
	 */
	protected function _unserialize($data)
	{
		$data = @unserialize(trim($data));

		if (is_array($data))
		{
			array_walk_recursive($data, array(&$this, '_unescape_slashes'));
			return $data;
		}

		return is_string($data) ? str_replace('{{slash}}', '\\', $data) : $data;
	}

	// ------------------------------------------------------------------------

	/**
	 * Unescape slashes
	 *
	 * This function converts any slash markers back into actual slashes
	 *
	 * @param	string	Value
	 * @param	string	Key
	 * @return	void
	 */
	protected function _unescape_slashes(&$val, $key)
	{
		if (is_string($val))
		{
	 		$val= str_replace('{{slash}}', '\\', $val);
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Garbage collection
	 *
	 * This deletes expired session rows from database
	 * if the probability percentage is met
	 *
	 * @return	void
	 */
	protected function _sess_gc()
	{
		if ($this->sess_use_database !== TRUE)
		{
			return;
		}

		$probability = ini_get('session.gc_probability');
		$divisor = ini_get('session.gc_divisor');

		srand(time());
		if ((mt_rand(0, $divisor) / $divisor) < $probability)
		{
			$expire = $this->now - $this->sess_expiration;
			$this->CI->db->delete($this->sess_table_name, 'last_activity < '.$expire);

			log_message('debug', 'Session garbage collection performed.');
		}
	}

}

/* End of file Session_cookie.php */
/* Location: ./system/libraries/Session/drivers/Session_cookie.php */