/halogy/libraries/Session.php
PHP | 758 lines | 397 code | 111 blank | 250 comment | 57 complexity | e9065a454a8aa10940d74878a96cebd9 MD5 | raw file
1<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); 2/** 3 * CodeIgniter 4 * 5 * An open source application development framework for PHP 4.3.2 or newer 6 * 7 * @package CodeIgniter 8 * @author ExpressionEngine Dev Team 9 * @copyright Copyright (c) 2008 - 2009, EllisLab, Inc. 10 * @license http://codeigniter.com/user_guide/license.html 11 * @link http://codeigniter.com 12 * @since Version 1.0 13 * @filesource 14 */ 15 16// ------------------------------------------------------------------------ 17 18/** 19 * Session Class 20 * 21 * @package CodeIgniter 22 * @subpackage Libraries 23 * @category Sessions 24 * @author ExpressionEngine Dev Team 25 * @link http://codeigniter.com/user_guide/libraries/sessions.html 26 */ 27class CI_Session { 28 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_match_ip = FALSE; 34 var $sess_match_useragent = TRUE; 35 var $sess_cookie_name = 'ci_session'; 36 var $cookie_prefix = ''; 37 var $cookie_path = ''; 38 var $cookie_domain = ''; 39 var $sess_time_to_update = 300; 40 var $encryption_key = ''; 41 var $flashdata_key = 'flash'; 42 var $time_reference = 'time'; 43 var $gc_probability = 5; 44 var $userdata = array(); 45 var $CI; 46 var $now; 47 48 /** 49 * Session Constructor 50 * 51 * The constructor runs the session routines automatically 52 * whenever the class is instantiated. 53 */ 54 function CI_Session($params = array()) 55 { 56 log_message('debug', "Session Class Initialized"); 57 58 // Set the super object to a local variable for use throughout the class 59 $this->CI =& get_instance(); 60 61 // Set all the session preferences, which can either be set 62 // manually via the $params array above or via the config file 63 foreach (array('sess_encrypt_cookie', 'sess_use_database', 'sess_table_name', 'sess_expiration', 'sess_match_ip', 'sess_match_useragent', 'sess_cookie_name', 'cookie_path', 'cookie_domain', 'sess_time_to_update', 'time_reference', 'cookie_prefix', 'encryption_key') as $key) 64 { 65 $this->$key = (isset($params[$key])) ? $params[$key] : $this->CI->config->item($key); 66 } 67 68 // Load the string helper so we can use the strip_slashes() function 69 $this->CI->load->helper('string'); 70 71 // Do we need encryption? If so, load the encryption class 72 if ($this->sess_encrypt_cookie == TRUE) 73 { 74 $this->CI->load->library('encrypt'); 75 } 76 77 // Are we using a database? If so, load it 78 if ($this->sess_use_database === TRUE AND $this->sess_table_name != '') 79 { 80 $this->CI->load->database(); 81 } 82 83 // Set the "now" time. Can either be GMT or server time, based on the 84 // config prefs. We use this to set the "last activity" time 85 $this->now = $this->_get_time(); 86 87 // Set the session length. If the session expiration is 88 // set to zero we'll set the expiration two years from now. 89 if ($this->sess_expiration == 0) 90 { 91 $this->sess_expiration = (60*60*24*365*2); 92 } 93 94 // Set the cookie name 95 $this->sess_cookie_name = $this->cookie_prefix.$this->sess_cookie_name; 96 97 // Run the Session routine. If a session doesn't exist we'll 98 // create a new one. If it does, we'll update it. 99 if ( ! $this->sess_read()) 100 { 101 $this->sess_create(); 102 } 103 else 104 { 105 $this->sess_update(); 106 } 107 108 // Delete 'old' flashdata (from last request) 109 $this->_flashdata_sweep(); 110 111 // Mark all new flashdata as old (data will be deleted before next request) 112 $this->_flashdata_mark(); 113 114 // Delete expired sessions if necessary 115 $this->_sess_gc(); 116 117 log_message('debug', "Session routines successfully run"); 118 } 119 120 // -------------------------------------------------------------------- 121 122 /** 123 * Fetch the current session data if it exists 124 * 125 * @access public 126 * @return bool 127 */ 128 function sess_read() 129 { 130 // Fetch the cookie 131 $session = $this->CI->input->cookie($this->sess_cookie_name); 132 133 // No cookie? Goodbye cruel world!... 134 if ($session === FALSE) 135 { 136 log_message('debug', 'A session cookie was not found.'); 137 return FALSE; 138 } 139 140 // Decrypt the cookie data 141 if ($this->sess_encrypt_cookie == TRUE) 142 { 143 $session = $this->CI->encrypt->decode($session); 144 } 145 else 146 { 147 // encryption was not used, so we need to check the md5 hash 148 $hash = substr($session, strlen($session)-32); // get last 32 chars 149 $session = substr($session, 0, strlen($session)-32); 150 151 // Does the md5 hash match? This is to prevent manipulation of session data in userspace 152 if ($hash !== md5($session.$this->encryption_key)) 153 { 154 log_message('error', 'The session cookie data did not match what was expected. This could be a possible hacking attempt.'); 155 $this->sess_destroy(); 156 return FALSE; 157 } 158 } 159 160 // Unserialize the session array 161 $session = $this->_unserialize($session); 162 163 // Is the session data we unserialized an array with the correct format? 164 if ( ! is_array($session) OR ! isset($session['session_id']) OR ! isset($session['ip_address']) OR ! isset($session['user_agent']) OR ! isset($session['last_activity'])) 165 { 166 $this->sess_destroy(); 167 return FALSE; 168 } 169 170 // Is the session current? 171 if (($session['last_activity'] + $this->sess_expiration) < $this->now) 172 { 173 $this->sess_destroy(); 174 return FALSE; 175 } 176 177 // Does the IP Match? 178 if ($this->sess_match_ip == TRUE AND $session['ip_address'] != $this->CI->input->ip_address()) 179 { 180 $this->sess_destroy(); 181 return FALSE; 182 } 183 184 // Does the User Agent Match? 185 if ($this->sess_match_useragent == TRUE AND trim($session['user_agent']) != trim(substr($this->CI->input->user_agent(), 0, 50))) 186 { 187 $this->sess_destroy(); 188 return FALSE; 189 } 190 191 // Is there a corresponding session in the DB? 192 if ($this->sess_use_database === TRUE) 193 { 194 $this->CI->db->where('session_id', $session['session_id']); 195 196 if ($this->sess_match_ip == TRUE) 197 { 198 $this->CI->db->where('ip_address', $session['ip_address']); 199 } 200 201 if ($this->sess_match_useragent == TRUE) 202 { 203 $this->CI->db->where('user_agent', $session['user_agent']); 204 } 205 206 $query = $this->CI->db->get($this->sess_table_name); 207 208 // No result? Kill it! 209 if ($query->num_rows() == 0) 210 { 211 $this->sess_destroy(); 212 return FALSE; 213 } 214 215 // Is there custom data? If so, add it to the main session array 216 $row = $query->row(); 217 if (isset($row->user_data) AND $row->user_data != '') 218 { 219 $custom_data = $this->_unserialize($row->user_data); 220 221 if (is_array($custom_data)) 222 { 223 foreach ($custom_data as $key => $val) 224 { 225 $session[$key] = $val; 226 } 227 } 228 } 229 } 230 231 // Session is valid! 232 $this->userdata = $session; 233 unset($session); 234 235 return TRUE; 236 } 237 238 // -------------------------------------------------------------------- 239 240 /** 241 * Write the session data 242 * 243 * @access public 244 * @return void 245 */ 246 function sess_write() 247 { 248 // Are we saving custom data to the DB? If not, all we do is update the cookie 249 if ($this->sess_use_database === FALSE) 250 { 251 $this->_set_cookie(); 252 return; 253 } 254 255 // set the custom userdata, the session data we will set in a second 256 $custom_userdata = $this->userdata; 257 $cookie_userdata = array(); 258 259 // Before continuing, we need to determine if there is any custom data to deal with. 260 // Let's determine this by removing the default indexes to see if there's anything left in the array 261 // and set the session data while we're at it 262 foreach (array('session_id','ip_address','user_agent','last_activity') as $val) 263 { 264 unset($custom_userdata[$val]); 265 $cookie_userdata[$val] = $this->userdata[$val]; 266 } 267 268 // Did we find any custom data? If not, we turn the empty array into a string 269 // since there's no reason to serialize and store an empty array in the DB 270 if (count($custom_userdata) === 0) 271 { 272 $custom_userdata = ''; 273 } 274 else 275 { 276 // Serialize the custom data array so we can store it 277 $custom_userdata = $this->_serialize($custom_userdata); 278 } 279 280 // Run the update query 281 $this->CI->db->where('session_id', $this->userdata['session_id']); 282 $this->CI->db->update($this->sess_table_name, array('last_activity' => $this->userdata['last_activity'], 'user_data' => $custom_userdata)); 283 284 // Write the cookie. Notice that we manually pass the cookie data array to the 285 // _set_cookie() function. Normally that function will store $this->userdata, but 286 // in this case that array contains custom data, which we do not want in the cookie. 287 $this->_set_cookie($cookie_userdata); 288 } 289 290 // -------------------------------------------------------------------- 291 292 /** 293 * Create a new session 294 * 295 * @access public 296 * @return void 297 */ 298 function sess_create() 299 { 300 $sessid = ''; 301 while (strlen($sessid) < 32) 302 { 303 $sessid .= mt_rand(0, mt_getrandmax()); 304 } 305 306 // To make the session ID even more secure we'll combine it with the user's IP 307 $sessid .= $this->CI->input->ip_address(); 308 309 $this->userdata = array( 310 'session_id' => md5(uniqid($sessid, TRUE)), 311 'ip_address' => $this->CI->input->ip_address(), 312 'user_agent' => substr($this->CI->input->user_agent(), 0, 50), 313 'last_activity' => $this->now 314 ); 315 316 317 // Save the data to the DB if needed 318 if ($this->sess_use_database === TRUE) 319 { 320 $this->CI->db->query($this->CI->db->insert_string($this->sess_table_name, $this->userdata)); 321 } 322 323 // Write the cookie 324 $this->_set_cookie(); 325 } 326 327 // -------------------------------------------------------------------- 328 329 /** 330 * Update an existing session 331 * 332 * @access public 333 * @return void 334 */ 335 function sess_update() 336 { 337 // We only update the session every five minutes by default 338 if (($this->userdata['last_activity'] + $this->sess_time_to_update) >= $this->now) 339 { 340 return; 341 } 342 343 // Save the old session id so we know which record to 344 // update in the database if we need it 345 $old_sessid = $this->userdata['session_id']; 346 $new_sessid = ''; 347 while (strlen($new_sessid) < 32) 348 { 349 $new_sessid .= mt_rand(0, mt_getrandmax()); 350 } 351 352 // To make the session ID even more secure we'll combine it with the user's IP 353 $new_sessid .= $this->CI->input->ip_address(); 354 355 // Turn it into a hash 356 $new_sessid = md5(uniqid($new_sessid, TRUE)); 357 358 // Update the session data in the session data array 359 $this->userdata['session_id'] = $new_sessid; 360 $this->userdata['last_activity'] = $this->now; 361 362 // _set_cookie() will handle this for us if we aren't using database sessions 363 // by pushing all userdata to the cookie. 364 $cookie_data = NULL; 365 366 // Update the session ID and last_activity field in the DB if needed 367 if ($this->sess_use_database === TRUE) 368 { 369 // set cookie explicitly to only have our session data 370 $cookie_data = array(); 371 foreach (array('session_id','ip_address','user_agent','last_activity') as $val) 372 { 373 $cookie_data[$val] = $this->userdata[$val]; 374 } 375 376 $this->CI->db->query($this->CI->db->update_string($this->sess_table_name, array('last_activity' => $this->now, 'session_id' => $new_sessid), array('session_id' => $old_sessid))); 377 } 378 379 // Write the cookie 380 $this->_set_cookie($cookie_data); 381 } 382 383 // -------------------------------------------------------------------- 384 385 /** 386 * Destroy the current session 387 * 388 * @access public 389 * @return void 390 */ 391 function sess_destroy() 392 { 393 // Kill the session DB row 394 if ($this->sess_use_database === TRUE AND isset($this->userdata['session_id'])) 395 { 396 $this->CI->db->where('session_id', $this->userdata['session_id']); 397 $this->CI->db->delete($this->sess_table_name); 398 } 399 400 // Kill the cookie 401 setcookie( 402 $this->sess_cookie_name, 403 addslashes(serialize(array())), 404 ($this->now - 31500000), 405 $this->cookie_path, 406 $this->cookie_domain, 407 0 408 ); 409 } 410 411 // -------------------------------------------------------------------- 412 413 /** 414 * Fetch a specific item from the session array 415 * 416 * @access public 417 * @param string 418 * @return string 419 */ 420 function userdata($item) 421 { 422 return ( ! isset($this->userdata[$item])) ? FALSE : $this->userdata[$item]; 423 } 424 425 // -------------------------------------------------------------------- 426 427 /** 428 * Fetch all session data 429 * 430 * @access public 431 * @return mixed 432 */ 433 function all_userdata() 434 { 435 return ( ! isset($this->userdata)) ? FALSE : $this->userdata; 436 } 437 438 // -------------------------------------------------------------------- 439 440 /** 441 * Add or change data in the "userdata" array 442 * 443 * @access public 444 * @param mixed 445 * @param string 446 * @return void 447 */ 448 function set_userdata($newdata = array(), $newval = '') 449 { 450 if (is_string($newdata)) 451 { 452 $newdata = array($newdata => $newval); 453 } 454 455 if (count($newdata) > 0) 456 { 457 foreach ($newdata as $key => $val) 458 { 459 $this->userdata[$key] = $val; 460 } 461 } 462 463 $this->sess_write(); 464 } 465 466 // -------------------------------------------------------------------- 467 468 /** 469 * Delete a session variable from the "userdata" array 470 * 471 * @access array 472 * @return void 473 */ 474 function unset_userdata($newdata = array()) 475 { 476 if (is_string($newdata)) 477 { 478 $newdata = array($newdata => ''); 479 } 480 481 if (count($newdata) > 0) 482 { 483 foreach ($newdata as $key => $val) 484 { 485 unset($this->userdata[$key]); 486 } 487 } 488 489 $this->sess_write(); 490 } 491 492 // ------------------------------------------------------------------------ 493 494 /** 495 * Add or change flashdata, only available 496 * until the next request 497 * 498 * @access public 499 * @param mixed 500 * @param string 501 * @return void 502 */ 503 function set_flashdata($newdata = array(), $newval = '') 504 { 505 if (is_string($newdata)) 506 { 507 $newdata = array($newdata => $newval); 508 } 509 510 if (count($newdata) > 0) 511 { 512 foreach ($newdata as $key => $val) 513 { 514 $flashdata_key = $this->flashdata_key.':new:'.$key; 515 $this->set_userdata($flashdata_key, $val); 516 } 517 } 518 } 519 520 // ------------------------------------------------------------------------ 521 522 /** 523 * Keeps existing flashdata available to next request. 524 * 525 * @access public 526 * @param string 527 * @return void 528 */ 529 function keep_flashdata($key) 530 { 531 // 'old' flashdata gets removed. Here we mark all 532 // flashdata as 'new' to preserve it from _flashdata_sweep() 533 // Note the function will return FALSE if the $key 534 // provided cannot be found 535 $old_flashdata_key = $this->flashdata_key.':old:'.$key; 536 $value = $this->userdata($old_flashdata_key); 537 538 $new_flashdata_key = $this->flashdata_key.':new:'.$key; 539 $this->set_userdata($new_flashdata_key, $value); 540 } 541 542 // ------------------------------------------------------------------------ 543 544 /** 545 * Fetch a specific flashdata item from the session array 546 * 547 * @access public 548 * @param string 549 * @return string 550 */ 551 function flashdata($key) 552 { 553 $flashdata_key = $this->flashdata_key.':old:'.$key; 554 return $this->userdata($flashdata_key); 555 } 556 557 // ------------------------------------------------------------------------ 558 559 /** 560 * Identifies flashdata as 'old' for removal 561 * when _flashdata_sweep() runs. 562 * 563 * @access private 564 * @return void 565 */ 566 function _flashdata_mark() 567 { 568 $userdata = $this->all_userdata(); 569 foreach ($userdata as $name => $value) 570 { 571 $parts = explode(':new:', $name); 572 if (is_array($parts) && count($parts) === 2) 573 { 574 $new_name = $this->flashdata_key.':old:'.$parts[1]; 575 $this->set_userdata($new_name, $value); 576 $this->unset_userdata($name); 577 } 578 } 579 } 580 581 // ------------------------------------------------------------------------ 582 583 /** 584 * Removes all flashdata marked as 'old' 585 * 586 * @access private 587 * @return void 588 */ 589 590 function _flashdata_sweep() 591 { 592 $userdata = $this->all_userdata(); 593 foreach ($userdata as $key => $value) 594 { 595 if (strpos($key, ':old:')) 596 { 597 $this->unset_userdata($key); 598 } 599 } 600 601 } 602 603 // -------------------------------------------------------------------- 604 605 /** 606 * Get the "now" time 607 * 608 * @access private 609 * @return string 610 */ 611 function _get_time() 612 { 613 if (strtolower($this->time_reference) == 'gmt') 614 { 615 $now = time(); 616 $time = mktime(gmdate("H", $now), gmdate("i", $now), gmdate("s", $now), gmdate("m", $now), gmdate("d", $now), gmdate("Y", $now)); 617 } 618 else 619 { 620 $time = time(); 621 } 622 623 return $time; 624 } 625 626 // -------------------------------------------------------------------- 627 628 /** 629 * Write the session cookie 630 * 631 * @access public 632 * @return void 633 */ 634 function _set_cookie($cookie_data = NULL) 635 { 636 if (is_null($cookie_data)) 637 { 638 $cookie_data = $this->userdata; 639 } 640 641 // Serialize the userdata for the cookie 642 $cookie_data = $this->_serialize($cookie_data); 643 644 if ($this->sess_encrypt_cookie == TRUE) 645 { 646 $cookie_data = $this->CI->encrypt->encode($cookie_data); 647 } 648 else 649 { 650 // if encryption is not used, we provide an md5 hash to prevent userside tampering 651 $cookie_data = $cookie_data.md5($cookie_data.$this->encryption_key); 652 } 653 654 // Set the cookie 655 setcookie( 656 $this->sess_cookie_name, 657 $cookie_data, 658 $this->sess_expiration + time(), 659 $this->cookie_path, 660 $this->cookie_domain, 661 0 662 ); 663 } 664 665 // -------------------------------------------------------------------- 666 667 /** 668 * Serialize an array 669 * 670 * This function first converts any slashes found in the array to a temporary 671 * marker, so when it gets unserialized the slashes will be preserved 672 * 673 * @access private 674 * @param array 675 * @return string 676 */ 677 function _serialize($data) 678 { 679 if (is_array($data)) 680 { 681 foreach ($data as $key => $val) 682 { 683 $data[$key] = str_replace('\\', '{{slash}}', $val); 684 } 685 } 686 else 687 { 688 $data = str_replace('\\', '{{slash}}', $data); 689 } 690 691 return serialize($data); 692 } 693 694 // -------------------------------------------------------------------- 695 696 /** 697 * Unserialize 698 * 699 * This function unserializes a data string, then converts any 700 * temporary slash markers back to actual slashes 701 * 702 * @access private 703 * @param array 704 * @return string 705 */ 706 function _unserialize($data) 707 { 708 $data = @unserialize(strip_slashes($data)); 709 710 if (is_array($data)) 711 { 712 foreach ($data as $key => $val) 713 { 714 $data[$key] = str_replace('{{slash}}', '\\', $val); 715 } 716 717 return $data; 718 } 719 720 return str_replace('{{slash}}', '\\', $data); 721 } 722 723 // -------------------------------------------------------------------- 724 725 /** 726 * Garbage collection 727 * 728 * This deletes expired session rows from database 729 * if the probability percentage is met 730 * 731 * @access public 732 * @return void 733 */ 734 function _sess_gc() 735 { 736 if ($this->sess_use_database != TRUE) 737 { 738 return; 739 } 740 741 srand(time()); 742 if ((rand() % 100) < $this->gc_probability) 743 { 744 $expire = $this->now - $this->sess_expiration; 745 746 $this->CI->db->where("last_activity < {$expire}"); 747 $this->CI->db->delete($this->sess_table_name); 748 749 log_message('debug', 'Session garbage collection performed.'); 750 } 751 } 752 753 754} 755// END Session Class 756 757/* End of file Session.php */ 758/* Location: ./system/libraries/Session.php */