src/Util/Security.php

   1 <?php
   2 /**
   3  * @file /src/Util/Security.php
   4  */
   5
   6 namespace Friendica\Util;
   7
   8 use Friendica\Database\DBA;
   9 use Friendica\Model\Contact;
  10 use Friendica\Model\Group;
  11 use Friendica\Model\User;
  12 use Friendica\Core\Session;
  13
  14 /**
  15  * Secures that User is allow to do requests
  16  */
  17 class Security
  18 {
  19         public static function canWriteToUserWall($owner)
  20         {
  21                 static $verified = 0;
  22
  23                 if (!Session::isAuthenticated()) {
  24                         return false;
  25                 }
  26
  27                 $uid = local_user();
  28                 if ($uid == $owner) {
  29                         return true;
  30                 }
  31
  32                 if (local_user() && ($owner == 0)) {
  33                         return true;
  34                 }
  35
  36                 if (!empty(Session::getRemoteContactID($owner))) {
  37                         // use remembered decision and avoid a DB lookup for each and every display item
  38                         // DO NOT use this function if there are going to be multiple owners
  39                         // We have a contact-id for an authenticated remote user, this block determines if the contact
  40                         // belongs to this page owner, and has the necessary permissions to post content
  41
  42                         if ($verified === 2) {
  43                                 return true;
  44                         } elseif ($verified === 1) {
  45                                 return false;
  46                         } else {
  47                                 $cid = Session::getRemoteContactID($owner);
  48                                 if (!$cid) {
  49                                         return false;
  50                                 }
  51
  52                                 $r = q("SELECT `contact`.*, `user`.`page-flags` FROM `contact` INNER JOIN `user` on `user`.`uid` = `contact`.`uid`
  53                                         WHERE `contact`.`uid` = %d AND `contact`.`id` = %d AND `contact`.`blocked` = 0 AND `contact`.`pending` = 0
  54                                         AND `user`.`blockwall` = 0 AND `readonly` = 0  AND (`contact`.`rel` IN (%d , %d) OR `user`.`page-flags` = %d) LIMIT 1",
  55                                         intval($owner),
  56                                         intval($cid),
  57                                         intval(Contact::SHARING),
  58                                         intval(Contact::FRIEND),
  59                                         intval(User::PAGE_FLAGS_COMMUNITY)
  60                                 );
  61
  62                                 if (DBA::isResult($r)) {
  63                                         $verified = 2;
  64                                         return true;
  65                                 } else {
  66                                         $verified = 1;
  67                                 }
  68                         }
  69                 }
  70
  71                 return false;
  72         }
  73
  74         public static function getPermissionsSQLByUserId($owner_id)
  75         {
  76                 $local_user = local_user();
  77                 $remote_contact = Session::getRemoteContactID($owner_id);
  78
  79                 /*
  80                  * Construct permissions
  81                  *
  82                  * default permissions - anonymous user
  83                  */
  84                 $sql = " AND allow_cid = ''
  85                          AND allow_gid = ''
  86                          AND deny_cid  = ''
  87                          AND deny_gid  = '' ";
  88
  89                 /*
  90                  * Profile owner - everything is visible
  91                  */
  92                 if ($local_user && $local_user == $owner_id) {
  93                         $sql = '';
  94                 /*
  95                  * Authenticated visitor. Load the groups the visitor belongs to.
  96                  */
  97                 } elseif ($remote_contact) {
  98                         $gs = '<<>>'; // should be impossible to match
  99
 100                         $groups = Group::getIdsByContactId($remote_contact);
 101
 102                         if (is_array($groups)) {
 103                                 foreach ($groups as $g) {
 104                                         $gs .= '|<' . intval($g) . '>';
 105                                 }
 106                         }
 107
 108                         $sql = sprintf(
 109                                 " AND (NOT (deny_cid REGEXP '<%d>' OR deny_gid REGEXP '%s')
 110                                   AND (allow_cid REGEXP '<%d>' OR allow_gid REGEXP '%s' OR (allow_cid = '' AND allow_gid = ''))) ",
 111                                 intval($remote_contact),
 112                                 DBA::escape($gs),
 113                                 intval($remote_contact),
 114                                 DBA::escape($gs)
 115                         );
 116                 }
 117                 return $sql;
 118         }
 119 }