summaryrefslogtreecommitdiffstats
path: root/system/libraries/Session/drivers/Session_files_driver.php
blob: d9966273b6e835888f7141e9dec50883d5c0c127 (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
<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2019, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @license	https://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 3.0.0
 * @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter Session Files Driver
 *
 * @package	CodeIgniter
 * @subpackage	Libraries
 * @category	Sessions
 * @author	Andrey Andreev
 * @link	https://codeigniter.com/user_guide/libraries/sessions.html
 */
class CI_Session_files_driver extends CI_Session_driver implements SessionHandlerInterface {

	/**
	 * Save path
	 *
	 * @var	string
	 */
	protected $_save_path;

	/**
	 * File handle
	 *
	 * @var	resource
	 */
	protected $_file_handle;

	/**
	 * File name
	 *
	 * @var	resource
	 */
	protected $_file_path;

	/**
	 * File new flag
	 *
	 * @var	bool
	 */
	protected $_file_new;

	/**
	 * Validate SID regular expression
	 *
	 * @var	string
	 */
	protected $_sid_regexp;

	/**
	 * mbstring.func_overload flag
	 *
	 * @var	bool
	 */
	protected static $func_overload;

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

	/**
	 * Class constructor
	 *
	 * @param	array	$params	Configuration parameters
	 * @return	void
	 */
	public function __construct(&$params)
	{
		parent::__construct($params);

		if (isset($this->_config['save_path']))
		{
			$this->_config['save_path'] = rtrim($this->_config['save_path'], '/\\');
			ini_set('session.save_path', $this->_config['save_path']);
		}
		else
		{
			log_message('debug', 'Session: "sess_save_path" is empty; using "session.save_path" value from php.ini.');
			$this->_config['save_path'] = rtrim(ini_get('session.save_path'), '/\\');
		}

		$this->_sid_regexp = $this->_config['_sid_regexp'];

		isset(self::$func_overload) OR self::$func_overload = (extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
	}

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

	/**
	 * Open
	 *
	 * Sanitizes the save_path directory.
	 *
	 * @param	string	$save_path	Path to session files' directory
	 * @param	string	$name		Session cookie name
	 * @return	bool
	 */
	public function open($save_path, $name)
	{
		if ( ! is_dir($save_path))
		{
			if ( ! mkdir($save_path, 0700, TRUE))
			{
				log_message('error', "Session: Configured save path '".$this->_config['save_path']."' is not a directory, doesn't exist or cannot be created.");
				return $this->_failure;
			}
		}
		elseif ( ! is_writable($save_path))
		{
			log_message('error', "Session: Configured save path '".$this->_config['save_path']."' is not writable by the PHP process.");
			return $this->_failure;
		}

		$this->_config['save_path'] = $save_path;
		$this->_file_path = $this->_config['save_path'].DIRECTORY_SEPARATOR
			.$name // we'll use the session cookie name as a prefix to avoid collisions
			.($this->_config['match_ip'] ? md5($_SERVER['REMOTE_ADDR']) : '');

		$this->php5_validate_id();

		return $this->_success;
	}

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

	/**
	 * Read
	 *
	 * Reads session data and acquires a lock
	 *
	 * @param	string	$session_id	Session ID
	 * @return	string	Serialized session data
	 */
	public function read($session_id)
	{
		// This might seem weird, but PHP 5.6 introduces session_reset(),
		// which re-reads session data
		if ($this->_file_handle === NULL)
		{
			$this->_file_new = ! file_exists($this->_file_path.$session_id);

			if (($this->_file_handle = fopen($this->_file_path.$session_id, 'c+b')) === FALSE)
			{
				log_message('error', "Session: Unable to open file '".$this->_file_path.$session_id."'.");
				return $this->_failure;
			}

			if (flock($this->_file_handle, LOCK_EX) === FALSE)
			{
				log_message('error', "Session: Unable to obtain lock for file '".$this->_file_path.$session_id."'.");
				fclose($this->_file_handle);
				$this->_file_handle = NULL;
				return $this->_failure;
			}

			// Needed by write() to detect session_regenerate_id() calls
			$this->_session_id = $session_id;

			if ($this->_file_new)
			{
				chmod($this->_file_path.$session_id, 0600);
				$this->_fingerprint = md5('');
				return '';
			}

			// Prevent possible data corruption
			// See https://github.com/bcit-ci/CodeIgniter/issues/5857
			clearstatcache(TRUE, $this->_file_path.$session_id);
		}
		// We shouldn't need this, but apparently we do ...
		// See https://github.com/bcit-ci/CodeIgniter/issues/4039
		elseif ($this->_file_handle === FALSE)
		{
			return $this->_failure;
		}
		else
		{
			rewind($this->_file_handle);
		}

		$session_data = '';
		for ($read = 0, $length = filesize($this->_file_path.$session_id); $read < $length; $read += self::strlen($buffer))
		{
			if (($buffer = fread($this->_file_handle, $length - $read)) === FALSE)
			{
				break;
			}

			$session_data .= $buffer;
		}

		$this->_fingerprint = md5($session_data);
		return $session_data;
	}

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

	/**
	 * Write
	 *
	 * Writes (create / update) session data
	 *
	 * @param	string	$session_id	Session ID
	 * @param	string	$session_data	Serialized session data
	 * @return	bool
	 */
	public function write($session_id, $session_data)
	{
		// If the two IDs don't match, we have a session_regenerate_id() call
		// and we need to close the old handle and open a new one
		if ($session_id !== $this->_session_id && ($this->close() === $this->_failure OR $this->read($session_id) === $this->_failure))
		{
			return $this->_failure;
		}

		if ( ! is_resource($this->_file_handle))
		{
			return $this->_failure;
		}
		elseif ($this->_fingerprint === md5($session_data))
		{
			return ( ! $this->_file_new && ! touch($this->_file_path.$session_id))
				? $this->_failure
				: $this->_success;
		}

		if ( ! $this->_file_new)
		{
			ftruncate($this->_file_handle, 0);
			rewind($this->_file_handle);
		}

		if (($length = strlen($session_data)) > 0)
		{
			for ($written = 0; $written < $length; $written += $result)
			{
				if (($result = fwrite($this->_file_handle, substr($session_data, $written))) === FALSE)
				{
					break;
				}
			}

			if ( ! is_int($result))
			{
				$this->_fingerprint = md5(substr($session_data, 0, $written));
				log_message('error', 'Session: Unable to write data.');
				return $this->_failure;
			}
		}

		$this->_fingerprint = md5($session_data);
		return $this->_success;
	}

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

	/**
	 * Close
	 *
	 * Releases locks and closes file descriptor.
	 *
	 * @return	bool
	 */
	public function close()
	{
		if (is_resource($this->_file_handle))
		{
			flock($this->_file_handle, LOCK_UN);
			fclose($this->_file_handle);

			$this->_file_handle = $this->_file_new = $this->_session_id = NULL;
		}

		return $this->_success;
	}

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

	/**
	 * Destroy
	 *
	 * Destroys the current session.
	 *
	 * @param	string	$session_id	Session ID
	 * @return	bool
	 */
	public function destroy($session_id)
	{
		if ($this->close() === $this->_success)
		{
			if (file_exists($this->_file_path.$session_id))
			{
				$this->_cookie_destroy();
				return unlink($this->_file_path.$session_id)
					? $this->_success
					: $this->_failure;
			}

			return $this->_success;
		}
		elseif ($this->_file_path !== NULL)
		{
			clearstatcache();
			if (file_exists($this->_file_path.$session_id))
			{
				$this->_cookie_destroy();
				return unlink($this->_file_path.$session_id)
					? $this->_success
					: $this->_failure;
			}

			return $this->_success;
		}

		return $this->_failure;
	}

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

	/**
	 * Garbage Collector
	 *
	 * Deletes expired sessions
	 *
	 * @param	int 	$maxlifetime	Maximum lifetime of sessions
	 * @return	bool
	 */
	public function gc($maxlifetime)
	{
		if ( ! is_dir($this->_config['save_path']) OR ($directory = opendir($this->_config['save_path'])) === FALSE)
		{
			log_message('debug', "Session: Garbage collector couldn't list files under directory '".$this->_config['save_path']."'.");
			return $this->_failure;
		}

		$ts = time() - $maxlifetime;

		$pattern = ($this->_config['match_ip'] === TRUE)
			? '[0-9a-f]{32}'
			: '';

		$pattern = sprintf(
			'#\A%s'.$pattern.$this->_sid_regexp.'\z#',
			preg_quote($this->_config['cookie_name'])
		);

		while (($file = readdir($directory)) !== FALSE)
		{
			// If the filename doesn't match this pattern, it's either not a session file or is not ours
			if ( ! preg_match($pattern, $file)
				OR ! is_file($this->_config['save_path'].DIRECTORY_SEPARATOR.$file)
				OR ($mtime = filemtime($this->_config['save_path'].DIRECTORY_SEPARATOR.$file)) === FALSE
				OR $mtime > $ts)
			{
				continue;
			}

			unlink($this->_config['save_path'].DIRECTORY_SEPARATOR.$file);
		}

		closedir($directory);

		return $this->_success;
	}

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

	/**
	 * Validate ID
	 *
	 * Checks whether a session ID record exists server-side,
	 * to enforce session.use_strict_mode.
	 *
	 * @param	string	$id
	 * @return	bool
	 */
	public function validateSessionId($id)
	{
		$result = is_file($this->_file_path.$id);
		clearstatcache(TRUE, $this->_file_path.$id);
		return $result;
	}

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

	/**
	 * Byte-safe strlen()
	 *
	 * @param	string	$str
	 * @return	int
	 */
	protected static function strlen($str)
	{
		return (self::$func_overload)
			? mb_strlen($str, '8bit')
			: strlen($str);
	}
}