summaryrefslogtreecommitdiff
path: root/program/include/rcmail.php
blob: 6352f80f87d10301bfd6bc55f9d08e65d979797a (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
<?php

/*
 +-----------------------------------------------------------------------+
 | program/include/rcmail.php                                            |
 |                                                                       |
 | This file is part of the RoundCube Webmail client                     |
 | Copyright (C) 2008, RoundCube Dev. - Switzerland                      |
 | Licensed under the GNU GPL                                            |
 |                                                                       |
 | PURPOSE:                                                              |
 |   Application class providing core functions and holding              |
 |   instances of all 'global' objects like db- and imap-connections     |
 +-----------------------------------------------------------------------+
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 +-----------------------------------------------------------------------+

 $Id: rcube_browser.php 328 2006-08-30 17:41:21Z thomasb $

*/


/**
 * Application class of RoundCube Webmail
 * implemented as singleton
 *
 * @package Core
 */
class rcmail
{
  static public $main_tasks = array('mail','settings','addressbook','login','logout');
  
  static private $instance;
  
  public $config;
  public $user;
  public $db;
  public $imap;
  public $output;
  public $task = 'mail';
  public $action = '';
  public $comm_path = './';
  
  private $texts;
  
  
  /**
   * This implements the 'singleton' design pattern
   *
   * @return object qvert The one and only instance
   */
  static function get_instance()
  {
    if (!self::$instance) {
      self::$instance = new rcmail();
      self::$instance->startup();  // init AFTER object was linked with self::$instance
    }

    return self::$instance;
  }
  
  
  /**
   * Private constructor
   */
  private function __construct()
  {
    // load configuration
    $this->config = new rcube_config();
    
    register_shutdown_function(array($this, 'shutdown'));
  }
  
  
  /**
   * Initial startup function
   * to register session, create database and imap connections
   *
   * @todo Remove global vars $DB, $USER
   */
  private function startup()
  {
    $config_all = $this->config->all();

    // set task and action properties
    $this->set_task(strip_quotes(get_input_value('_task', RCUBE_INPUT_GPC)));
    $this->action = strip_quotes(get_input_value('_action', RCUBE_INPUT_GPC));

    // connect to database
    $GLOBALS['DB'] = $this->get_dbh();

    // use database for storing session data
    include_once('include/session.inc');

    // set session domain
    if (!empty($config_all['session_domain'])) {
      ini_set('session.cookie_domain', $config_all['session_domain']);
    }
    // set session garbage collecting time according to session_lifetime
    if (!empty($config_all['session_lifetime'])) {
      ini_set('session.gc_maxlifetime', ($config_all['session_lifetime']) * 120);
    }

    // start PHP session (if not in CLI mode)
    if ($_SERVER['REMOTE_ADDR'])
      session_start();

    // set initial session vars
    if (!isset($_SESSION['auth_time'])) {
      $_SESSION['auth_time'] = time();
      $_SESSION['temp'] = true;
    }


    // create user object
    $this->set_user(new rcube_user($_SESSION['user_id']));

    // reset some session parameters when changing task
    if ($_SESSION['task'] != $this->task)
      unset($_SESSION['page']);

    // set current task to session
    $_SESSION['task'] = $this->task;

    // create IMAP object
    if ($this->task == 'mail')
      $this->imap_init();
  }
  
  
  /**
   * Setter for application task
   *
   * @param string Task to set
   */
  public function set_task($task)
  {
    if (!in_array($task, self::$main_tasks))
      $task = 'mail';
    
    $this->task = $task;
    $this->comm_path = './?_task=' . $task;
    
    if ($this->output)
      $this->output->set_env('task', $task);
  }
  
  
  /**
   * Setter for system user object
   *
   * @param object rcube_user Current user instance
   */
  public function set_user($user)
  {
    if (is_object($user)) {
      $this->user = $user;
      $GLOBALS['USER'] = $this->user;
      
      // overwrite config with user preferences
      $this->config->merge((array)$this->user->get_prefs());
    }
    
    $_SESSION['language'] = $this->user->language = $this->language_prop($this->config->get('language'));

    // set localization
    setlocale(LC_ALL, $_SESSION['language'] . '.utf8');
  }
  
  
  /**
   * Check the given string and return a valid language code
   *
   * @param string Language code
   * @return string Valid language code
   */
  private function language_prop($lang)
  {
    static $rcube_languages, $rcube_language_aliases;

    if (empty($rcube_languages)) {
      @include(INSTALL_PATH . 'program/localization/index.inc');
    }
    
    // check if we have an alias for that language
    if (!isset($rcube_languages[$lang]) && isset($rcube_language_aliases[$lang])) {
      $lang = $rcube_language_aliases[$lang];
    }
    // try the first two chars
    else if (!isset($rcube_languages[$lang])) {
      $short = $this->language_prop(substr($lang, 0, 2));
      
      // check if we have an alias for the short language code
      if (!isset($rcube_languages[$short]) && isset($rcube_language_aliases[$short])) {
        $lang = $rcube_language_aliases[$short];
      }
      // expand 'nn' to 'nn_NN'
      else if (!isset($rcube_languages[$short])) {
        $lang = $short.'_'.strtoupper($short);
      }
    }

    if (!isset($rcube_languages[$lang]) || !is_dir(INSTALL_PATH . 'program/localization/' . $lang)) {
      $lang = 'en_US';
    }

    return $lang;
  }
  
  
  /**
   * Get the current database connection
   *
   * @return object rcube_db  Database connection object
   */
  public function get_dbh()
  {
    if (!$this->db) {
      $dbclass = "rcube_" . $this->config->get('db_backend', 'mdb2');
      $config_all = $this->config->all();

      $this->db = new $dbclass($config_all['db_dsnw'], $config_all['db_dsnr'], $config_all['db_persistent']);
      $this->db->sqlite_initials = INSTALL_PATH . 'SQL/sqlite.initial.sql';
      $this->db->set_debug((bool)$config_all['sql_debug']);
      $this->db->db_connect('w');
    }

    return $this->db;
  }
  
  
  /**
   * Init output object for GUI and add common scripts.
   * This will instantiate a rcmail_template object and set
   * environment vars according to the current session and configuration
   */
  public function load_gui($framed = false)
  {
    // init output page
    $this->output = new rcube_template($this->task, $framed);

    foreach (array('flag_for_deletion') as $js_config_var) {
      $this->output->set_env($js_config_var, $this->config->get($js_config_var));
    }

    if ($framed) {
      $this->comm_path .= '&_framed=1';
      $this->output->set_env('framed', true);
    }

    $this->output->set_env('task', $this->task);
    $this->output->set_env('action', $this->action);
    $this->output->set_env('comm_path', $this->comm_path);
    $this->output->set_charset($this->config->get('charset', RCMAIL_CHARSET));

    // add some basic label to client
    $this->output->add_label('loading');
    
    return $this->output;
  }
  
  
  /**
   * Create an output object for JSON responses
   */
  public function init_json()
  {
    $this->output = new rcube_json_output($this->task);
    
    return $this->output;
  }
  
  
  /**
   * Create global IMAP object and connect to server
   *
   * @param boolean True if connection should be established
   * @todo Remove global $IMAP
   */
  public function imap_init($connect = false)
  {
    $this->imap = new rcube_imap($this->db);
    $this->imap->debug_level = $this->config->get('debug_level');
    $this->imap->skip_deleted = $this->config->get('skip_deleted');

    // enable caching of imap data
    if ($this->config->get('enable_caching')) {
      $this->imap->set_caching(true);
    }

    // set pagesize from config
    $this->imap->set_pagesize($this->config->get('pagesize', 50));
  
    // set global object for backward compatibility
    $GLOBALS['IMAP'] = $this->imap;
    
    if ($connect)
      $this->imap_connect();
  }


  /**
   * Connect to IMAP server with stored session data
   *
   * @return bool True on success, false on error
   */
  public function imap_connect()
  {
    $conn = false;
    
    if ($_SESSION['imap_host']) {
      if (!($conn = $this->imap->connect($_SESSION['imap_host'], $_SESSION['username'], $this->decrypt_passwd($_SESSION['password']), $_SESSION['imap_port'], $_SESSION['imap_ssl'], rcmail::get_instance()->config->get('imap_auth_type', 'check')))) {
        if ($this->output)
          $this->output->show_message($this->imap->error_code == -1 ? 'imaperror' : 'sessionerror', 'error');
      }

      $this->set_imap_prop();
    }

    return $conn;    
  }


  /**
   * Perfom login to the IMAP server and to the webmail service.
   * This will also create a new user entry if auto_create_user is configured.
   *
   * @param string IMAP user name
   * @param string IMAP password
   * @param string IMAP host
   * @return boolean True on success, False on failure
   */
  function login($username, $pass, $host=NULL)
  {
    $user = NULL;
    $config = $this->config->all();

    if (!$host)
      $host = $config['default_host'];

    // Validate that selected host is in the list of configured hosts
    if (is_array($config['default_host'])) {
      $allowed = false;
      foreach ($config['default_host'] as $key => $host_allowed) {
        if (!is_numeric($key))
          $host_allowed = $key;
        if ($host == $host_allowed) {
          $allowed = true;
          break;
        }
      }
      if (!$allowed)
        return false;
      }
    else if (!empty($config['default_host']) && $host != $config['default_host'])
      return false;

    // parse $host URL
    $a_host = parse_url($host);
    if ($a_host['host']) {
      $host = $a_host['host'];
      $imap_ssl = (isset($a_host['scheme']) && in_array($a_host['scheme'], array('ssl','imaps','tls'))) ? $a_host['scheme'] : null;
      $imap_port = isset($a_host['port']) ? $a_host['port'] : ($imap_ssl ? 993 : $config['default_port']);
    }
    else
      $imap_port = $config['default_port'];


    /* Modify username with domain if required  
       Inspired by Marco <P0L0_notspam_binware.org>
    */
    // Check if we need to add domain
    if (!empty($config['username_domain']) && !strpos($username, '@')) {
      if (is_array($config['username_domain']) && isset($config['username_domain'][$host]))
        $username .= '@'.$config['username_domain'][$host];
      else if (is_string($config['username_domain']))
        $username .= '@'.$config['username_domain'];
    }

    // try to resolve email address from virtuser table    
    if (!empty($config['virtuser_file']) && strpos($username, '@'))
      $username = rcube_user::email2user($username);

    // lowercase username if it's an e-mail address (#1484473)
    if (strpos($username, '@'))
      $username = strtolower($username);

    // user already registered -> overwrite username
    if ($user = rcube_user::query($username, $host))
      $username = $user->data['username'];

    // exit if IMAP login failed
    if (!($imap_login  = $this->imap->connect($host, $username, $pass, $imap_port, $imap_ssl, $config['imap_auth_type'])))
      return false;

    // user already registered -> update user's record
    if (is_object($user)) {
      $user->touch();
    }
    // create new system user
    else if ($config['auto_create_user']) {
      if ($created = rcube_user::create($username, $host)) {
        $user = $created;

        // get existing mailboxes (but why?)
        // $a_mailboxes = $this->imap->list_mailboxes();
      }
    }
    else {
      raise_error(array(
        'code' => 600,
        'type' => 'php',
        'file' => "config/main.inc.php",
        'message' => "Acces denied for new user $username. 'auto_create_user' is disabled"
        ), true, false);
    }

    // login succeeded
    if (is_object($user) && $user->ID) {
      $this->set_user($user);

      // set session vars
      $_SESSION['user_id']   = $user->ID;
      $_SESSION['username']  = $user->data['username'];
      $_SESSION['imap_host'] = $host;
      $_SESSION['imap_port'] = $imap_port;
      $_SESSION['imap_ssl']  = $imap_ssl;
      $_SESSION['password']  = $this->encrypt_passwd($pass);
      $_SESSION['login_time'] = mktime();

      // force reloading complete list of subscribed mailboxes
      $this->set_imap_prop();
      $this->imap->clear_cache('mailboxes');

      if ($config['create_default_folders'])
          $this->imap->create_default_folders();

      return true;
    }

    return false;
  }


  /**
   * Set root dir and last stored mailbox
   * This must be done AFTER connecting to the server!
   */
  public function set_imap_prop()
  {
    $this->imap->set_charset($this->config->get('default_charset', RCMAIL_CHARSET));

    // set root dir from config
    if ($imap_root = $this->config->get('imap_root')) {
      $this->imap->set_rootdir($imap_root);
    }
    if ($default_folders = $this->config->get('default_imap_folders')) {
      $this->imap->set_default_mailboxes($default_folders);
    }
    if (!empty($_SESSION['mbox'])) {
      $this->imap->set_mailbox($_SESSION['mbox']);
    }
    if (isset($_SESSION['page'])) {
      $this->imap->set_page($_SESSION['page']);
    }
  }


  /**
   * Auto-select IMAP host based on the posted login information
   *
   * @return string Selected IMAP host
   */
  public function autoselect_host()
  {
    $default_host = $this->config->get('default_host');
    $host = !empty($default_host) ? get_input_value('_host', RCUBE_INPUT_POST) : $default_host;
    
    if (is_array($host)) {
      list($user, $domain) = explode('@', get_input_value('_user', RCUBE_INPUT_POST));
      if (!empty($domain)) {
        foreach ($host as $imap_host => $mail_domains) {
          if (is_array($mail_domains) && in_array($domain, $mail_domains)) {
            $host = $imap_host;
            break;
          }
        }
      }

      // take the first entry if $host is still an array
      if (is_array($host))
        $host = array_shift($host);
    }

    return $host;
  }


  /**
   * Get localized text in the desired language
   *
   * @param mixed Named parameters array or label name
   * @return string Localized text
   */
  public function gettext($attrib)
  {
    // load localization files if not done yet
    if (empty($this->texts))
      $this->load_language();
    
    // extract attributes
    if (is_string($attrib))
      $attrib = array('name' => $attrib);

    $nr = is_numeric($attrib['nr']) ? $attrib['nr'] : 1;
    $vars = isset($attrib['vars']) ? $attrib['vars'] : '';

    $command_name = !empty($attrib['command']) ? $attrib['command'] : NULL;
    $alias = $attrib['name'] ? $attrib['name'] : ($command_name && $command_label_map[$command_name] ? $command_label_map[$command_name] : '');

    // text does not exist
    if (!($text_item = $this->texts[$alias])) {
      /*
      raise_error(array(
        'code' => 500,
        'type' => 'php',
        'line' => __LINE__,
        'file' => __FILE__,
        'message' => "Missing localized text for '$alias' in '$sess_user_lang'"), TRUE, FALSE);
      */
      return "[$alias]";
    }

    // make text item array 
    $a_text_item = is_array($text_item) ? $text_item : array('single' => $text_item);

    // decide which text to use
    if ($nr == 1) {
      $text = $a_text_item['single'];
    }
    else if ($nr > 0) {
      $text = $a_text_item['multiple'];
    }
    else if ($nr == 0) {
      if ($a_text_item['none'])
        $text = $a_text_item['none'];
      else if ($a_text_item['single'])
        $text = $a_text_item['single'];
      else if ($a_text_item['multiple'])
        $text = $a_text_item['multiple'];
    }

    // default text is single
    if ($text == '') {
      $text = $a_text_item['single'];
    }

    // replace vars in text
    if (is_array($attrib['vars'])) {
      foreach ($attrib['vars'] as $var_key => $var_value)
        $a_replace_vars[$var_key{0}=='$' ? substr($var_key, 1) : $var_key] = $var_value;
    }

    if ($a_replace_vars)
      $text = preg_replace('/\$\{?([_a-z]{1}[_a-z0-9]*)\}?/ei', '$a_replace_vars["\1"]', $text);

    // format output
    if (($attrib['uppercase'] && strtolower($attrib['uppercase']=='first')) || $attrib['ucfirst'])
      return ucfirst($text);
    else if ($attrib['uppercase'])
      return strtoupper($text);
    else if ($attrib['lowercase'])
      return strtolower($text);

    return $text;
  }


  /**
   * Load a localization package
   *
   * @param string Language ID
   */
  public function load_language($lang = null)
  {
    $lang = $lang ? $this->language_prop($lang) : $_SESSION['language'];
    
    // load localized texts
    if (empty($this->texts) || $lang != $_SESSION['language']) {
      $this->texts = array();

      // get english labels (these should be complete)
      @include(INSTALL_PATH . 'program/localization/en_US/labels.inc');
      @include(INSTALL_PATH . 'program/localization/en_US/messages.inc');

      if (is_array($labels))
        $this->texts = $labels;
      if (is_array($messages))
        $this->texts = array_merge($this->texts, $messages);

      // include user language files
      if ($lang != 'en' && is_dir(INSTALL_PATH . 'program/localization/' . $lang)) {
        include_once(INSTALL_PATH . 'program/localization/' . $lang . '/labels.inc');
        include_once(INSTALL_PATH . 'program/localization/' . $lang . '/messages.inc');

        if (is_array($labels))
          $this->texts = array_merge($this->texts, $labels);
        if (is_array($messages))
          $this->texts = array_merge($this->texts, $messages);
      }
      
      $_SESSION['language'] = $lang;
    }
  }


  /**
   * Read directory program/localization and return a list of available languages
   *
   * @return array List of available localizations
   */
  public function list_languages()
  {
    static $sa_languages = array();

    if (!sizeof($sa_languages)) {
      @include(INSTALL_PATH . 'program/localization/index.inc');

      if ($dh = @opendir(INSTALL_PATH . 'program/localization')) {
        while (($name = readdir($dh)) !== false) {
          if ($name{0}=='.' || !is_dir(INSTALL_PATH . 'program/localization/' . $name))
            continue;

          if ($label = $rcube_languages[$name])
            $sa_languages[$name] = $label ? $label : $name;
        }
        closedir($dh);
      }
    }

    return $sa_languages;
  }


  /**
   * Check the auth hash sent by the client against the local session credentials
   *
   * @return boolean True if valid, False if not
   */
  function authenticate_session()
  {
    global $SESS_CLIENT_IP, $SESS_CHANGED;

    // advanced session authentication
    if ($this->config->get('double_auth')) {
      $now = time();
      $valid = ($_COOKIE['sessauth'] == $this->get_auth_hash(session_id(), $_SESSION['auth_time']) ||
                $_COOKIE['sessauth'] == $this->get_auth_hash(session_id(), $_SESSION['last_auth']));

      // renew auth cookie every 5 minutes (only for GET requests)
      if (!$valid || ($_SERVER['REQUEST_METHOD']!='POST' && $now - $_SESSION['auth_time'] > 300)) {
        $_SESSION['last_auth'] = $_SESSION['auth_time'];
        $_SESSION['auth_time'] = $now;
        setcookie('sessauth', $this->get_auth_hash(session_id(), $now));
      }
    }
    else {
      $valid = $this->config->get('ip_check') ? $_SERVER['REMOTE_ADDR'] == $SESS_CLIENT_IP : true;
    }

    // check session filetime
    $lifetime = $this->config->get('session_lifetime');
    if (!empty($lifetime) && isset($SESS_CHANGED) && $SESS_CHANGED + $lifetime*60 < time()) {
      $valid = false;
    }

    return $valid;
  }


  /**
   * Destroy session data and remove cookie
   */
  public function kill_session()
  {
    $user_prefs = $this->user->get_prefs();
    
    if ((isset($_SESSION['sort_col']) && $_SESSION['sort_col'] != $user_prefs['message_sort_col']) ||
        (isset($_SESSION['sort_order']) && $_SESSION['sort_order'] != $user_prefs['message_sort_order'])) {
      $this->user->save_prefs(array('message_sort_col' => $_SESSION['sort_col'], 'message_sort_order' => $_SESSION['sort_order']));
    }

    $_SESSION = array('language' => $USER->language, 'auth_time' => time(), 'temp' => true);
    setcookie('sessauth', '-del-', time() - 60);
    $this->user->reset();
  }


  /**
   * Do server side actions on logout
   */
  public function logout_actions()
  {
    $config = $this->config->all();
    
    // on logout action we're not connected to imap server  
    if (($config['logout_purge'] && !empty($config['trash_mbox'])) || $config['logout_expunge']) {
      if (!$this->authenticate_session())
        return;

      $this->imap_init(true);
    }

    if ($config['logout_purge'] && !empty($config['trash_mbox'])) {
      $this->imap->clear_mailbox($config['trash_mbox']);
    }

    if ($config['logout_expunge']) {
      $this->imap->expunge('INBOX');
    }
  }


  /**
   * Function to be executed in script shutdown
   * Registered with register_shutdown_function()
   */
  public function shutdown()
  {
    if (is_object($this->imap)) {
      $this->imap->close();
      $this->imap->write_cache();
    }

    if (is_object($this->contacts))
      $this->contacts->close();

    // before closing the database connection, write session data
    if ($_SERVER['REMOTE_ADDR'])
      session_write_close();
  }
  
  
  /**
   * Create unique authorization hash
   *
   * @param string Session ID
   * @param int Timestamp
   * @return string The generated auth hash
   */
  private function get_auth_hash($sess_id, $ts)
  {
    $auth_string = sprintf('rcmail*sess%sR%s*Chk:%s;%s',
      $sess_id,
      $ts,
      $this->config->get('ip_check') ? $_SERVER['REMOTE_ADDR'] : '***.***.***.***',
      $_SERVER['HTTP_USER_AGENT']);

    if (function_exists('sha1'))
      return sha1($auth_string);
    else
      return md5($auth_string);
  }

  /**
   * Encrypt IMAP password using DES encryption
   *
   * @param string Password to encrypt
   * @return string Encryprted string
   */
  public function encrypt_passwd($pass)
  {
    if (function_exists('mcrypt_module_open') && ($td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, ""))) {
      $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
      mcrypt_generic_init($td, $this->config->get_des_key(), $iv);
      $cypher = mcrypt_generic($td, $pass);
      mcrypt_generic_deinit($td);
      mcrypt_module_close($td);
    }
    else if (function_exists('des')) {
      $cypher = des($this->config->get_des_key(), $pass, 1, 0, NULL);
    }
    else {
      $cypher = $pass;

      raise_error(array(
        'code' => 500,
        'type' => 'php',
        'file' => __FILE__,
        'message' => "Could not convert encrypt password. Make sure Mcrypt is installed or lib/des.inc is available"
        ), true, false);
    }

    return base64_encode($cypher);
  }


  /**
   * Decrypt IMAP password using DES encryption
   *
   * @param string Encrypted password
   * @return string Plain password
   */
  public function decrypt_passwd($cypher)
  {
    if (function_exists('mcrypt_module_open') && ($td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, ""))) {
      $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
      mcrypt_generic_init($td, $this->config->get_des_key(), $iv);
      $pass = mdecrypt_generic($td, base64_decode($cypher));
      mcrypt_generic_deinit($td);
      mcrypt_module_close($td);
    }
    else if (function_exists('des')) {
      $pass = des($this->config->get_des_key(), base64_decode($cypher), 0, 0, NULL);
    }
    else {
      $pass = base64_decode($cypher);
    }

    return preg_replace('/\x00/', '', $pass);
  }

}