summaryrefslogtreecommitdiff
path: root/program/lib/Roundcube/rcube_ldap_generic.php
blob: 097ddafd5722e1407aa8077370916f0aefffe1ae (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
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
<?php

/*
 +-----------------------------------------------------------------------+
 | Roundcube/rcube_ldap_generic.php                                      |
 |                                                                       |
 | This file is part of the Roundcube Webmail client                     |
 | Copyright (C) 2006-2013, The Roundcube Dev Team                       |
 | Copyright (C) 2012-2013, Kolab Systems AG                             |
 |                                                                       |
 | Licensed under the GNU General Public License version 3 or            |
 | any later version with exceptions for skins & plugins.                |
 | See the README file for a full license statement.                     |
 |                                                                       |
 | PURPOSE:                                                              |
 |   Provide basic functionality for accessing LDAP directories          |
 |                                                                       |
 +-----------------------------------------------------------------------+
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 |         Aleksander Machniak <machniak@kolabsys.com>                   |
 +-----------------------------------------------------------------------+
*/


/*
  LDAP connection properties
  --------------------------

  $prop = array(
      'host'            => '<ldap-server-address>',
      // or
      'hosts'           => array('directory.verisign.com'),
      'port'            => 389,
      'use_tls'         => true|false,
      'ldap_version'    => 3,             // using LDAPv3
      'auth_method'     => '',            // SASL authentication method (for proxy auth), e.g. DIGEST-MD5
      'attributes'      => array('dn'),   // List of attributes to read from the server
      'vlv'             => false,         // Enable Virtual List View to more efficiently fetch paginated data (if server supports it)
      'config_root_dn'  => 'cn=config',   // Root DN to read config (e.g. vlv indexes) from
      'numsub_filter'   => '(objectClass=organizationalUnit)',   // with VLV, we also use numSubOrdinates to query the total number of records. Set this filter to get all numSubOrdinates attributes for counting
      'sizelimit'       => '0',           // Enables you to limit the count of entries fetched. Setting this to 0 means no limit.
      'timelimit'       => '0',           // Sets the number of seconds how long is spend on the search. Setting this to 0 means no limit.
      'network_timeout' => 10,            // The timeout (in seconds) for connect + bind arrempts. This is only supported in PHP >= 5.3.0 with OpenLDAP 2.x
      'referrals'       => true|false,    // Sets the LDAP_OPT_REFERRALS option. Mostly used in multi-domain Active Directory setups
  );
*/

/**
 * Model class to access an LDAP directories
 *
 * @package    Framework
 * @subpackage LDAP
 */
class rcube_ldap_generic
{
    const UPDATE_MOD_ADD = 1;
    const UPDATE_MOD_DELETE = 2;
    const UPDATE_MOD_REPLACE = 4;
    const UPDATE_MOD_FULL = 7;

    public $conn;
    public $vlv_active = false;

    /** private properties */
    protected $cache = null;
    protected $config = array();
    protected $attributes = array('dn');
    protected $entries = null;
    protected $result = null;
    protected $debug = false;
    protected $list_page = 1;
    protected $page_size = 10;
    protected $vlv_config = null;


    /**
    * Object constructor
    *
    * @param array $p LDAP connection properties
    */
    function __construct($p)
    {
        $this->config = $p;

        if (is_array($p['attributes']))
            $this->attributes = $p['attributes'];

        if (!is_array($p['hosts']) && !empty($p['host']))
            $this->config['hosts'] = array($p['host']);
    }

    /**
     * Activate/deactivate debug mode
     *
     * @param boolean $dbg True if LDAP commands should be logged
     */
    public function set_debug($dbg = true)
    {
        $this->debug = $dbg;
    }

    /**
     * Set connection options
     *
     * @param mixed $opt Option name as string or hash array with multiple options
     * @param mixed $val Option value
     */
    public function set_config($opt, $val = null)
    {
        if (is_array($opt))
            $this->config = array_merge($this->config, $opt);
        else
            $this->config[$opt] = $value;
    }

    /**
     * Enable caching by passing an instance of rcube_cache to be used by this object
     *
     * @param object rcube_cache Instance or False to disable caching
     */
    public function set_cache($cache_engine)
    {
        $this->cache = $cache_engine;
    }

    /**
     * Set properties for VLV-based paging
     *
     * @param  number $page  Page number to list (starting at 1)
     * @param  number $size  Number of entries to display on one page
     */
    public function set_vlv_page($page, $size = 10)
    {
        $this->list_page = $page;
        $this->page_size = $size;
    }

    /**
    * Establish a connection to the LDAP server
    */
    public function connect($host = null)
    {
        if (!function_exists('ldap_connect')) {
            rcube::raise_error(array('code' => 100, 'type' => 'ldap',
                'file' => __FILE__, 'line' => __LINE__,
                'message' => "No ldap support in this installation of PHP"),
                true);
            return false;
        }

        if (is_resource($this->conn) && $this->config['host'] == $host)
            return true;

        if (empty($this->config['ldap_version']))
            $this->config['ldap_version'] = 3;

        // iterate over hosts if none specified
        if (!$host) {
            if (!is_array($this->config['hosts']))
                $this->config['hosts'] = array($this->config['hosts']);

            foreach ($this->config['hosts'] as $host) {
                if ($this->connect($host)) {
                    return true;
                }
            }

            return false;
        }

        // open connection to the given $host
        $host     = rcube_utils::idn_to_ascii(rcube_utils::parse_host($host));
        $hostname = $host . ($this->config['port'] ? ':'.$this->config['port'] : '');

        $this->_debug("C: Connect to $hostname [{$this->config['name']}]");

        if ($lc = @ldap_connect($host, $this->config['port'])) {
            if ($this->config['use_tls'] === true)
                if (!ldap_start_tls($lc))
                    continue;

            $this->_debug("S: OK");

            ldap_set_option($lc, LDAP_OPT_PROTOCOL_VERSION, $this->config['ldap_version']);
            $this->config['host'] = $host;
            $this->conn = $lc;

            if (!empty($this->config['network_timeout']))
              ldap_set_option($lc, LDAP_OPT_NETWORK_TIMEOUT, $this->config['network_timeout']);

            if (isset($this->config['referrals']))
                ldap_set_option($lc, LDAP_OPT_REFERRALS, $this->config['referrals']);
        }
        else {
            $this->_debug("S: NOT OK");
        }

        if (!is_resource($this->conn)) {
            rcube::raise_error(array('code' => 100, 'type' => 'ldap',
                'file' => __FILE__, 'line' => __LINE__,
                'message' => "Could not connect to any LDAP server, last tried $hostname"),
                true);
            return false;
        }

        return true;
    }

    /**
     * Bind connection with (SASL-) user and password
     *
     * @param string $authc Authentication user
     * @param string $pass  Bind password
     * @param string $authz Autorization user
     *
     * @return boolean True on success, False on error
     */
    public function sasl_bind($authc, $pass, $authz=null)
    {
        if (!$this->conn) {
            return false;
        }

        if (!function_exists('ldap_sasl_bind')) {
            rcube::raise_error(array('code' => 100, 'type' => 'ldap',
                'file' => __FILE__, 'line' => __LINE__,
                'message' => "Unable to bind: ldap_sasl_bind() not exists"),
                true);
            return false;
        }

        if (!empty($authz)) {
            $authz = 'u:' . $authz;
        }

        if (!empty($this->config['auth_method'])) {
            $method = $this->config['auth_method'];
        }
        else {
            $method = 'DIGEST-MD5';
        }

        $this->_debug("C: SASL Bind [mech: $method, authc: $authc, authz: $authz, pass: $pass]");

        if (ldap_sasl_bind($this->conn, NULL, $pass, $method, NULL, $authc, $authz)) {
            $this->_debug("S: OK");
            return true;
        }

        $this->_debug("S: ".ldap_error($this->conn));

        rcube::raise_error(array(
            'code' => ldap_errno($this->conn), 'type' => 'ldap',
            'file' => __FILE__, 'line' => __LINE__,
            'message' => "SASL Bind failed for authcid=$authc ".ldap_error($this->conn)),
            true);
        return false;
    }

    /**
     * Bind connection with DN and password
     *
     * @param string $dn   Bind DN
     * @param string $pass Bind password
     *
     * @return boolean True on success, False on error
     */
    public function bind($dn, $pass)
    {
        if (!$this->conn) {
            return false;
        }

        $this->_debug("C: Bind $dn [pass: $pass]");

        if (@ldap_bind($this->conn, $dn, $pass)) {
            $this->_debug("S: OK");
            return true;
        }

        $this->_debug("S: ".ldap_error($this->conn));

        rcube::raise_error(array(
            'code' => ldap_errno($this->conn), 'type' => 'ldap',
            'file' => __FILE__, 'line' => __LINE__,
            'message' => "Bind failed for dn=$dn: ".ldap_error($this->conn)),
            true);

        return false;
    }

    /**
     * Close connection to LDAP server
     */
    public function close()
    {
        if ($this->conn) {
            $this->_debug("C: Close");
            ldap_unbind($this->conn);
            $this->conn = null;
        }
    }

    /**
     * Return the last result set
     *
     * @return object rcube_ldap_result Result object
     */
    function get_result()
    {
        return $this->result;
    }

    /**
     * Get a specific LDAP entry, identified by its DN
     *
     * @param string $dn Record identifier
     * @return array     Hash array
     */
    function get_entry($dn)
    {
        $rec = null;

        if ($this->conn && $dn) {
            $this->_debug("C: Read $dn [(objectclass=*)]");

            if ($ldap_result = @ldap_read($this->conn, $dn, '(objectclass=*)', $this->attributes)) {
                $this->_debug("S: OK");

                if ($entry = ldap_first_entry($this->conn, $ldap_result)) {
                    $rec = ldap_get_attributes($this->conn, $entry);
                }
            }
            else {
                $this->_debug("S: ".ldap_error($this->conn));
            }

            if (!empty($rec)) {
                $rec['dn'] = $dn; // Add in the dn for the entry.
            }
        }

        return $rec;
    }

    /**
     * Execute the LDAP search based on the stored credentials
     *
     * @param string $base_dn  The base DN to query
     * @param string $filter   The LDAP filter for search
     * @param string $scope    The LDAP scope (list|sub|base)
     * @param array  $attrs    List of entry attributes to read
     * @param array  $prop     Hash array with query configuration properties:
     *   - sort: array of sort attributes (has to be in sync with the VLV index)
     *   - search: search string used for VLV controls
     * @param boolean $count_only Set to true if only entry count is requested
     *
     * @return mixed  rcube_ldap_result object or number of entries (if count_only=true) or false on error
     */
    public function search($base_dn, $filter = '', $scope = 'sub', $attrs = array('dn'), $prop = array(), $count_only = false)
    {
        if ($this->conn) {
            if (empty($filter))
                $filter = $filter = '(objectclass=*)';

            $this->_debug("C: Search $base_dn for $filter");

            $function = self::scope2func($scope, $ns_function);

            // find available VLV index for this query
            if (!$count_only && ($vlv_sort = $this->_find_vlv($base_dn, $filter, $scope, $prop['sort']))) {
                // when using VLV, we get the total count by...
                // ...either reading numSubOrdinates attribute
                if ($this->config['numsub_filter'] && ($result_count = @$ns_function($this->conn, $base_dn, $this->config['numsub_filter'], array('numSubOrdinates'), 0, 0, 0))) {
                    $counts = ldap_get_entries($this->conn, $result_count);
                    for ($vlv_count = $j = 0; $j < $counts['count']; $j++)
                        $vlv_count += $counts[$j]['numsubordinates'][0];
                    $this->_debug("D: total numsubordinates = " . $vlv_count);
                }
                // ...or by fetching all records dn and count them
                else if (!function_exists('ldap_parse_virtuallist_control')) {
                    $vlv_count = $this->search($base_dn, $filter, $scope, array('dn'), $prop, true);
                }

                $this->vlv_active = $this->_vlv_set_controls($vlv_sort, $this->list_page, $this->page_size, $prop['search']);
            }
            else {
                $this->vlv_active = false;
            }

            // only fetch dn for count (should keep the payload low)
            if ($ldap_result = @$function($this->conn, $base_dn, $filter,
                $attrs, 0, (int)$this->config['sizelimit'], (int)$this->config['timelimit'])
            ) {
                // when running on a patched PHP we can use the extended functions to retrieve the total count from the LDAP search result
                if ($this->vlv_active && function_exists('ldap_parse_virtuallist_control')) {
                    if (ldap_parse_result($this->conn, $ldap_result, $errcode, $matcheddn, $errmsg, $referrals, $serverctrls)) {
                        ldap_parse_virtuallist_control($this->conn, $serverctrls, $last_offset, $vlv_count, $vresult);
                        $this->_debug("S: VLV result: last_offset=$last_offset; content_count=$vlv_count");
                    }
                    else {
                        $this->_debug("S: ".($errmsg ? $errmsg : ldap_error($this->conn)));
                    }
                }
                else if ($this->debug) {
                    $this->_debug("S: ".ldap_count_entries($this->conn, $ldap_result)." record(s) found");
                }

                $this->result = new rcube_ldap_result($this->conn, $ldap_result, $base_dn, $filter, $vlv_count);

                return $count_only ? $this->result->count() : $this->result;
            }
            else {
                $this->_debug("S: ".ldap_error($this->conn));
            }
        }

        return false;
    }

    /**
     * Modify an LDAP entry on the server
     *
     * @param string $dn      Entry DN
     * @param array  $params  Hash array of entry attributes
     * @param int    $mode    Update mode (UPDATE_MOD_ADD | UPDATE_MOD_DELETE | UPDATE_MOD_REPLACE)
     */
    public function modify($dn, $parms, $mode = 255)
    {
        // TODO: implement this

        return false;
    }

    /**
     * Wrapper for ldap_add()
     *
     * @see ldap_add()
     */
    public function add($dn, $entry)
    {
        $this->_debug("C: Add $dn: ".print_r($entry, true));

        $res = ldap_add($this->conn, $dn, $entry);
        if ($res === false) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_delete()
     *
     * @see ldap_delete()
     */
    public function delete($dn)
    {
        $this->_debug("C: Delete $dn");

        $res = ldap_delete($this->conn, $dn);
        if ($res === false) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_mod_replace()
     *
     * @see ldap_mod_replace()
     */
    public function mod_replace($dn, $entry)
    {
        $this->_debug("C: Replace $dn: ".print_r($entry, true));

        if (!ldap_mod_replace($this->conn, $dn, $entry)) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_mod_add()
     *
     * @see ldap_mod_add()
     */
    public function mod_add($dn, $entry)
    {
        $this->_debug("C: Add $dn: ".print_r($entry, true));

        if (!ldap_mod_add($this->conn, $dn, $entry)) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_mod_del()
     *
     * @see ldap_mod_del()
     */
    public function mod_del($dn, $entry)
    {
        $this->_debug("C: Delete $dn: ".print_r($entry, true));

        if (!ldap_mod_del($this->conn, $dn, $entry)) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_rename()
     *
     * @see ldap_rename()
     */
    public function rename($dn, $newrdn, $newparent = null, $deleteoldrdn = true)
    {
        $this->_debug("C: Rename $dn to $newrdn");

        if (!ldap_rename($this->conn, $dn, $newrdn, $newparent, $deleteoldrdn)) {
            $this->_debug("S: ".ldap_error($this->conn));
            return false;
        }

        $this->_debug("S: OK");
        return true;
    }

    /**
     * Wrapper for ldap_list() + ldap_get_entries()
     *
     * @see ldap_list()
     * @see ldap_get_entries()
     */
    public function list_entries($dn, $filter, $attributes = array('dn'))
    {
        $list = array();
        $this->_debug("C: List $dn [{$filter}]");

        if ($result = ldap_list($this->conn, $dn, $filter, $attributes)) {
            $list = ldap_get_entries($this->conn, $result);

            if ($list === false) {
                $this->_debug("S: ".ldap_error($this->conn));
                return array();
            }

            $count = $list['count'];
            unset($list['count']);

            $this->_debug("S: $count record(s)");
        }
        else {
            $this->_debug("S: ".ldap_error($this->conn));
        }

        return $list;
    }

    /**
     * Wrapper for ldap_read() + ldap_get_entries()
     *
     * @see ldap_read()
     * @see ldap_get_entries()
     */
    public function read_entries($dn, $filter, $attributes = null)
    {
        $this->_debug("C: Read $dn [{$filter}]");

        if ($this->conn && $dn) {
            if (!$attributes)
                $attributes = $this->attributes;

            $result = @ldap_read($this->conn, $dn, $filter, $attributes, 0, (int)$this->config['sizelimit'], (int)$this->config['timelimit']);
            if ($result === false) {
                $this->_debug("S: ".ldap_error($this->conn));
                return false;
            }

            $this->_debug("S: OK");
            return ldap_get_entries($this->conn, $result);
        }

        return false;
    }

    /**
     * Choose the right PHP function according to scope property
     *
     * @param string $scope         The LDAP scope (sub|base|list)
     * @param string $ns_function   Function to be used for numSubOrdinates queries
     * @return string  PHP function to be used to query directory
     */
    public static function scope2func($scope, &$ns_function = null)
    {
        switch ($scope) {
          case 'sub':
            $function = $ns_function  = 'ldap_search';
            break;
          case 'base':
            $function = $ns_function = 'ldap_read';
            break;
          default:
            $function = 'ldap_list';
            $ns_function = 'ldap_read';
            break;
        }

        return $function;
    }

    /**
     * Convert the given scope integer value to a string representation
     */
    public static function scopeint2str($scope)
    {
        switch ($scope) {
            case 2:  return 'sub';
            case 1:  return 'one';
            case 0:  return 'base';
            default: $this->_debug("Scope $scope is not a valid scope integer");
        }

        return '';
    }

    /**
     * Escapes the given value according to RFC 2254 so that it can be safely used in LDAP filters.
     *
     * @param string $val Value to quote
     * @return string The escaped value
     */
    public static function escape_value($val)
    {
        return strtr($str, array('*'=>'\2a', '('=>'\28', ')'=>'\29',
            '\\'=>'\5c', '/'=>'\2f'));
    }

    /**
     * Escapes a DN value according to RFC 2253
     *
     * @param string $dn DN value o quote
     * @return string The escaped value
     */
    public static function escape_dn($dn)
    {
        return strtr($str, array(','=>'\2c', '='=>'\3d', '+'=>'\2b',
            '<'=>'\3c', '>'=>'\3e', ';'=>'\3b', '\\'=>'\5c',
            '"'=>'\22', '#'=>'\23'));
    }

    /**
     * Normalize a LDAP result by converting entry attributes arrays into single values
     *
     * @param array $result LDAP result set fetched with ldap_get_entries()
     * @return array        Hash array with normalized entries, indexed by their DNs
     */
    public static function normalize_result($result)
    {
        if (!is_array($result)) {
            return array();
        }

        $entries  = array();
        for ($i = 0; $i < $result['count']; $i++) {
            $key = $result[$i]['dn'] ? $result[$i]['dn'] : $i;
            $entries[$key] = self::normalize_entry($result[$i]);
        }

        return $entries;
    }

    /**
     * Turn an LDAP entry into a regular PHP array with attributes as keys.
     *
     * @param array $entry Attributes array as retrieved from ldap_get_attributes() or ldap_get_entries()
     * @return array       Hash array with attributes as keys
     */
    public static function normalize_entry($entry)
    {
        $rec = array();
        for ($i=0; $i < $entry['count']; $i++) {
            $attr = $entry[$i];
            if ($entry[$attr]['count'] == 1) {
                switch ($attr) {
                    case 'objectclass':
                        $rec[$attr] = array(strtolower($entry[$attr][0]));
                        break;
                    default:
                        $rec[$attr] = $entry[$attr][0];
                        break;
                }
            }
            else {
                for ($j=0; $j < $entry[$attr]['count']; $j++) {
                    $rec[$attr][$j] = $entry[$attr][$j];
                }
            }
        }

        return $rec;
    }

    /**
     * Set server controls for Virtual List View (paginated listing)
     */
    private function _vlv_set_controls($sort, $list_page, $page_size, $search = null)
    {
        $sort_ctrl = array('oid' => "1.2.840.113556.1.4.473",  'value' => self::_sort_ber_encode((array)$sort));
        $vlv_ctrl  = array('oid' => "2.16.840.1.113730.3.4.9", 'value' => self::_vlv_ber_encode(($offset = ($list_page-1) * $page_size + 1), $page_size, $search), 'iscritical' => true);

        $this->_debug("C: Set controls sort=" . join(' ', unpack('H'.(strlen($sort_ctrl['value'])*2), $sort_ctrl['value'])) . " ($sort[0]);"
            . " vlv=" . join(' ', (unpack('H'.(strlen($vlv_ctrl['value'])*2), $vlv_ctrl['value']))) . " ($offset/$page_size; $search)");

        if (!ldap_set_option($this->conn, LDAP_OPT_SERVER_CONTROLS, array($sort_ctrl, $vlv_ctrl))) {
            $this->_debug("S: ".ldap_error($this->conn));
            $this->set_error(self::ERROR_SEARCH, 'vlvnotsupported');
            return false;
        }

        return true;
    }

    /**
     * Returns unified attribute name (resolving aliases)
     */
    private static function _attr_name($namev)
    {
        // list of known attribute aliases
        static $aliases = array(
            'gn' => 'givenname',
            'rfc822mailbox' => 'email',
            'userid' => 'uid',
            'emailaddress' => 'email',
            'pkcs9email' => 'email',
        );

        list($name, $limit) = explode(':', $namev, 2);
        $suffix = $limit ? ':'.$limit : '';

        return (isset($aliases[$name]) ? $aliases[$name] : $name) . $suffix;
    }

    /**
     * Quotes attribute value string
     *
     * @param string $str Attribute value
     * @param bool   $dn  True if the attribute is a DN
     *
     * @return string Quoted string
     */
    public static function quote_string($str, $dn=false)
    {
        // take firt entry if array given
        if (is_array($str))
            $str = reset($str);

        if ($dn)
            $replace = array(','=>'\2c', '='=>'\3d', '+'=>'\2b', '<'=>'\3c',
                '>'=>'\3e', ';'=>'\3b', '\\'=>'\5c', '"'=>'\22', '#'=>'\23');
        else
            $replace = array('*'=>'\2a', '('=>'\28', ')'=>'\29', '\\'=>'\5c',
                '/'=>'\2f');

        return strtr($str, $replace);
    }

    /**
     * Prints debug info to the log
     */
    private function _debug($str)
    {
        if ($this->debug && class_exists('rcube')) {
            rcube::write_log('ldap', $str);
        }
    }


    /*****************  Virtual List View (VLV) related utility functions  **************** */

    /**
     * Return the search string value to be used in VLV controls
     */
    private function _vlv_search($sort, $search)
    {
        foreach ($search as $attr => $value) {
            if (!in_array(strtolower($attr), $sort)) {
                $this->_debug("d: Cannot use VLV search using attribute not indexed: $attr (not in " . var_export($sort, true) . ")");
                return null;
            } else {
                return $value;
            }
        }
    }

    /**
     * Find a VLV index matching the given query attributes
     *
     * @return string Sort attribute or False if no match
     */
    private function _find_vlv($base_dn, $filter, $scope, $sort_attrs = null)
    {
        if (!$this->config['vlv'] || $scope == 'base') {
            return false;
        }

        // get vlv config
        $vlv_config = $this->_read_vlv_config();

        if ($vlv = $vlv_config[$base_dn]) {
            $this->_debug("D: Found a VLV for $base_dn");

            if ($vlv['filter'] == strtolower($filter) || stripos($filter, '(&'.$vlv['filter'].'(') === 0) {
                $this->_debug("D: Filter matches");
                if ($vlv['scope'] == $scope) {
                    // Not passing any sort attributes means you don't care
                    if (empty($sort_attrs) || in_array($sort_attrs, $vlv['sort'])) {
                        return $vlv['sort'][0];
                    }
                }
                else {
                    $this->_debug("D: Scope does not match");
                }
            }
            else {
                $this->_debug("D: Filter does not match");
            }
        }
        else {
            $this->_debug("D: No VLV for $base_dn");
        }

        return false;
    }

    /**
     * Return VLV indexes and searches including necessary configuration
     * details.
     */
    private function _read_vlv_config()
    {
        if (empty($this->config['vlv']) || empty($this->config['config_root_dn'])) {
            return array();
        }
        // return hard-coded VLV config
        else if (is_array($this->config['vlv'])) {
            return $this->config['vlv'];
        }

        // return cached result
        if (is_array($this->vlv_config)) {
            return $this->vlv_config;
        }

        if ($this->cache && ($cached_config = $this->cache->get('vlvconfig'))) {
            $this->vlv_config = $cached_config;
            return $this->vlv_config;
        }

        $this->vlv_config = array();

        $ldap_result = ldap_search($this->conn, $this->config['config_root_dn'], '(objectclass=vlvsearch)', array('*'), 0, 0, 0);
        $vlv_searches = new rcube_ldap_result($this->conn, $ldap_result, $this->config['config_root_dn'], '(objectclass=vlvsearch)');

        if ($vlv_searches->count() < 1) {
            $this->_debug("D: Empty result from search for '(objectclass=vlvsearch)' on '$config_root_dn'");
            return array();
        }

        foreach ($vlv_searches->entries(true) as $vlv_search_dn => $vlv_search_attrs) {
            // Multiple indexes may exist
            $ldap_result = ldap_search($this->conn, $vlv_search_dn, '(objectclass=vlvindex)', array('*'), 0, 0, 0);
            $vlv_indexes = new rcube_ldap_result($this->conn, $ldap_result, $vlv_search_dn, '(objectclass=vlvindex)');

            // Reset this one for each VLV search.
            $_vlv_sort = array();
            foreach ($vlv_indexes->entries(true) as $vlv_index_dn => $vlv_index_attrs) {
                $_vlv_sort[] = explode(' ', $vlv_index_attrs['vlvsort']);
            }

            $this->vlv_config[$vlv_search_attrs['vlvbase']] = array(
                'scope'  => self::scopeint2str($vlv_search_attrs['vlvscope']),
                'filter' => strtolower($vlv_search_attrs['vlvfilter']),
                'sort'   => $_vlv_sort,
            );
        }

        // cache this
        if ($this->cache)
            $this->cache->set('vlvconfig', $this->vlv_config);

        $this->_debug("D: Refreshed VLV config: " . var_export($this->vlv_config, true));

        return $this->vlv_config;
    }

    /**
     * Generate BER encoded string for Virtual List View option
     *
     * @param integer List offset (first record)
     * @param integer Records per page
     *
     * @return string BER encoded option value
     */
    private static function _vlv_ber_encode($offset, $rpp, $search = '')
    {
        /*
            this string is ber-encoded, php will prefix this value with:
            04 (octet string) and 10 (length of 16 bytes)
            the code behind this string is broken down as follows:
            30 = ber sequence with a length of 0e (14) bytes following
            02 = type integer (in two's complement form) with 2 bytes following (beforeCount): 01 00 (ie 0)
            02 = type integer (in two's complement form) with 2 bytes following (afterCount):  01 18 (ie 25-1=24)
            a0 = type context-specific/constructed with a length of 06 (6) bytes following
            02 = type integer with 2 bytes following (offset): 01 01 (ie 1)
            02 = type integer with 2 bytes following (contentCount):  01 00

            with a search string present:
            81 = type context-specific/constructed with a length of 04 (4) bytes following (the length will change here)
            81 indicates a user string is present where as a a0 indicates just a offset search
            81 = type context-specific/constructed with a length of 06 (6) bytes following

            The following info was taken from the ISO/IEC 8825-1:2003 x.690 standard re: the
            encoding of integer values (note: these values are in
            two-complement form so since offset will never be negative bit 8 of the
            leftmost octet should never by set to 1):
            8.3.2: If the contents octets of an integer value encoding consist
            of more than one octet, then the bits of the first octet (rightmost)
            and bit 8 of the second (to the left of first octet) octet:
                a) shall not all be ones; and
                b) shall not all be zero
        */

        if ($search) {
            $search = preg_replace('/[^-[:alpha:] ,.()0-9]+/', '', $search);
            $ber_val = self::_string2hex($search);
            $str = self::_ber_addseq($ber_val, '81');
        }
        else {
            // construct the string from right to left
            $str = "020100"; # contentCount

            $ber_val = self::_ber_encode_int($offset);  // returns encoded integer value in hex format

            // calculate octet length of $ber_val
            $str = self::_ber_addseq($ber_val, '02') . $str;

            // now compute length over $str
            $str = self::_ber_addseq($str, 'a0');
        }

        // now tack on records per page
        $str = "020100" . self::_ber_addseq(self::_ber_encode_int($rpp-1), '02') . $str;

        // now tack on sequence identifier and length
        $str = self::_ber_addseq($str, '30');

        return pack('H'.strlen($str), $str);
    }

    /**
     * create ber encoding for sort control
     *
     * @param array List of cols to sort by
     * @return string BER encoded option value
     */
    private static function _sort_ber_encode($sortcols)
    {
        $str = '';
        foreach (array_reverse((array)$sortcols) as $col) {
            $ber_val = self::_string2hex($col);

            // 30 = ber sequence with a length of octet value
            // 04 = octet string with a length of the ascii value
            $oct = self::_ber_addseq($ber_val, '04');
            $str = self::_ber_addseq($oct, '30') . $str;
        }

        // now tack on sequence identifier and length
        $str = self::_ber_addseq($str, '30');

        return pack('H'.strlen($str), $str);
    }

    /**
     * Add BER sequence with correct length and the given identifier
     */
    private static function _ber_addseq($str, $identifier)
    {
        $len = dechex(strlen($str)/2);
        if (strlen($len) % 2 != 0)
            $len = '0'.$len;

        return $identifier . $len . $str;
    }

    /**
     * Returns BER encoded integer value in hex format
     */
    private static function _ber_encode_int($offset)
    {
        $val = dechex($offset);
        $prefix = '';

        // check if bit 8 of high byte is 1
        if (preg_match('/^[89abcdef]/', $val))
            $prefix = '00';

        if (strlen($val)%2 != 0)
            $prefix .= '0';

        return $prefix . $val;
    }

    /**
     * Returns ascii string encoded in hex
     */
    private static function _string2hex($str)
    {
        $hex = '';
        for ($i=0; $i < strlen($str); $i++) {
            $hex .= dechex(ord($str[$i]));
        }
        return $hex;
    }

}