Rename lib/dokuwiki to vendors/dokuwiki

1 files changed, 942 insertions, 0 deletions

diff --git a/vendors/dokuwiki/inc/auth/mysql.class.php b/vendors/dokuwiki/inc/auth/mysql.class.php
new file mode 100644
index 000000000..b1c6a3a52
--- /dev/null
+++ b/vendors/dokuwiki/inc/auth/mysql.class.php
@@ -0,0 +1,942 @@
+<?php
+/**
+ * MySQLP authentication backend
+ *
+ * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ * @author     Andreas Gohr <andi@splitbrain.org>
+ * @author     Chris Smith <chris@jalakai.co.uk>
+ * @author     Matthias Grimm <matthias.grimmm@sourceforge.net>
+*/
+
+define('DOKU_AUTH', dirname(__FILE__));
+require_once(DOKU_AUTH.'/basic.class.php');
+
+class auth_mysql extends auth_basic {
+
+    var $dbcon        = 0;
+    var $dbver        = 0;    // database version
+    var $dbrev        = 0;    // database revision
+    var $dbsub        = 0;    // database subrevision
+    var $cnf          = null;
+    var $defaultgroup = "";
+
+    /**
+     * Constructor
+     *
+     * checks if the mysql interface is available, otherwise it will
+     * set the variable $success of the basis class to false
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function auth_mysql() {
+      global $conf;
+      $this->cnf          = $conf['auth']['mysql'];
+
+      if (method_exists($this, 'auth_basic'))
+        parent::auth_basic();
+
+      if(!function_exists('mysql_connect')) {
+        if ($this->cnf['debug'])
+          msg("MySQL err: PHP MySQL extension not found.",-1,__LINE__,__FILE__);
+        $this->success = false;
+        return;
+      }
+
+      // default to UTF-8, you rarely want something else
+      if(!isset($this->cnf['charset'])) $this->cnf['charset'] = 'utf8';
+
+      $this->defaultgroup = $conf['defaultgroup'];
+
+      // set capabilities based upon config strings set
+      if (empty($this->cnf['server']) || empty($this->cnf['user']) ||
+          empty($this->cnf['password']) || empty($this->cnf['database'])){
+        if ($this->cnf['debug'])
+          msg("MySQL err: insufficient configuration.",-1,__LINE__,__FILE__);
+        $this->success = false;
+        return;
+      }
+
+      $this->cando['addUser']      = $this->_chkcnf(array('getUserInfo',
+                                                          'getGroups',
+                                                          'addUser',
+                                                          'getUserID',
+                                                          'getGroupID',
+                                                          'addGroup',
+                                                          'addUserGroup'),true);
+      $this->cando['delUser']      = $this->_chkcnf(array('getUserID',
+                                                          'delUser',
+                                                          'delUserRefs'),true);
+      $this->cando['modLogin']     = $this->_chkcnf(array('getUserID',
+                                                          'updateUser',
+                                                          'UpdateTarget'),true);
+      $this->cando['modPass']      = $this->cando['modLogin'];
+      $this->cando['modName']      = $this->cando['modLogin'];
+      $this->cando['modMail']      = $this->cando['modLogin'];
+      $this->cando['modGroups']    = $this->_chkcnf(array('getUserID',
+                                                          'getGroups',
+                                                          'getGroupID',
+                                                          'addGroup',
+                                                          'addUserGroup',
+                                                          'delGroup',
+                                                          'getGroupID',
+                                                          'delUserGroup'),true);
+      /* getGroups is not yet supported
+      $this->cando['getGroups']    = $this->_chkcnf(array('getGroups',
+                                                          'getGroupID'),false); */
+      $this->cando['getUsers']     = $this->_chkcnf(array('getUsers',
+                                                          'getUserInfo',
+                                                          'getGroups'),false);
+      $this->cando['getUserCount'] = $this->_chkcnf(array('getUsers'),false);
+    }
+
+    /**
+     * Check if the given config strings are set
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     * @return  bool
+     */
+    function _chkcnf($keys, $wop=false){
+      foreach ($keys as $key){
+        if (empty($this->cnf[$key])) return false;
+      }
+
+      /* write operation and lock array filled with tables names? */
+      if ($wop && (!is_array($this->cnf['TablesToLock']) ||
+                   !count($this->cnf['TablesToLock']))){
+        return false;
+      }
+
+      return true;
+    }
+
+    /**
+     * Checks if the given user exists and the given plaintext password
+     * is correct. Furtheron it might be checked wether the user is
+     * member of the right group
+     *
+     * Depending on which SQL string is defined in the config, password
+     * checking is done here (getpass) or by the database (passcheck)
+     *
+     * @param  $user  user who would like access
+     * @param  $pass  user's clear text password to check
+     * @return bool
+     *
+     * @author  Andreas Gohr <andi@splitbrain.org>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function checkPass($user,$pass){
+      $rc  = false;
+
+      if($this->_openDB()) {
+        $sql    = str_replace('%{user}',$this->_escape($user),$this->cnf['checkPass']);
+        $sql    = str_replace('%{pass}',$this->_escape($pass),$sql);
+        $sql    = str_replace('%{dgroup}',$this->_escape($this->defaultgroup),$sql);
+        $result = $this->_queryDB($sql);
+
+        if($result !== false && count($result) == 1) {
+          if($this->cnf['forwardClearPass'] == 1)
+            $rc = true;
+          else
+            $rc = auth_verifyPassword($pass,$result[0]['pass']);
+        }
+        $this->_closeDB();
+      }
+      return $rc;
+    }
+
+    /**
+     * [public function]
+     *
+     * Returns info about the given user needs to contain
+     * at least these fields:
+     *   name  string  full name of the user
+     *   mail  string  email addres of the user
+     *   grps  array   list of groups the user is in
+     *
+     * @param $user   user's nick to get data for
+     *
+     * @author  Andreas Gohr <andi@splitbrain.org>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function getUserData($user){
+      if($this->_openDB()) {
+        $this->_lockTables("READ");
+        $info = $this->_getUserInfo($user);
+        $this->_unlockTables();
+        $this->_closeDB();
+      } else
+        $info = false;
+      return $info;
+    }
+
+    /**
+     * [public function]
+     *
+     * Create a new User. Returns false if the user already exists,
+     * null when an error occurred and true if everything went well.
+     *
+     * The new user will be added to the default group by this
+     * function if grps are not specified (default behaviour).
+     *
+     * @param $user  nick of the user
+     * @param $pwd   clear text password
+     * @param $name  full name of the user
+     * @param $mail  email address
+     * @param $grps  array of groups the user should become member of
+     *
+     * @author  Andreas Gohr <andi@splitbrain.org>
+     * @author  Chris Smith <chris@jalakai.co.uk>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function createUser($user,$pwd,$name,$mail,$grps=null){
+      if($this->_openDB()) {
+        if (($info = $this->_getUserInfo($user)) !== false)
+          return false;  // user already exists
+
+        // set defaultgroup if no groups were given
+        if ($grps == null)
+          $grps = array($this->defaultgroup);
+
+        $this->_lockTables("WRITE");
+        $pwd = $this->cnf['forwardClearPass'] ? $pwd : auth_cryptPassword($pwd);
+        $rc = $this->_addUser($user,$pwd,$name,$mail,$grps);
+        $this->_unlockTables();
+        $this->_closeDB();
+        if ($rc) return true;
+      }
+      return null;  // return error
+    }
+
+    /**
+     * Modify user data [public function]
+     *
+     * An existing user dataset will be modified. Changes are given in an array.
+     *
+     * The dataset update will be rejected if the user name should be changed
+     * to an already existing one.
+     *
+     * The password must be provides unencrypted. Pasword cryption is done
+     * automatically if configured.
+     *
+     * If one or more groups could't be updated, an error would be set. In
+     * this case the dataset might already be changed and we can't rollback
+     * the changes. Transactions would be really usefull here.
+     *
+     * modifyUser() may be called without SQL statements defined that are
+     * needed to change group membership (for example if only the user profile
+     * should be modified). In this case we asure that we don't touch groups
+     * even $changes['grps'] is set by mistake.
+     *
+     * @param   $user     nick of the user to be changed
+     * @param   $changes  array of field/value pairs to be changed (password
+     *                    will be clear text)
+     * @return  bool      true on success, false on error
+     *
+     * @author  Chris Smith <chris@jalakai.co.uk>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function modifyUser($user, $changes) {
+      $rc = false;
+
+      if (!is_array($changes) || !count($changes))
+        return true;  // nothing to change
+
+      if($this->_openDB()) {
+        $this->_lockTables("WRITE");
+
+        if (($uid = $this->_getUserID($user))) {
+          $rc = $this->_updateUserInfo($changes, $uid);
+
+          if ($rc && isset($changes['grps']) && $this->cando['modGroups']) {
+            $groups = $this->_getGroups($user);
+            $grpadd = array_diff($changes['grps'], $groups);
+            $grpdel = array_diff($groups, $changes['grps']);
+
+            foreach($grpadd as $group)
+              if (($this->_addUserToGroup($user, $group, 1)) == false)
+                $rc = false;
+
+            foreach($grpdel as $group)
+              if (($this->_delUserFromGroup($user, $group)) == false)
+                $rc = false;
+          }
+        }
+
+        $this->_unlockTables();
+        $this->_closeDB();
+      }
+      return $rc;
+    }
+
+    /**
+     * [public function]
+     *
+     * Remove one or more users from the list of registered users
+     *
+     * @param   array  $users   array of users to be deleted
+     * @return  int             the number of users deleted
+     *
+     * @author  Christopher Smith <chris@jalakai.co.uk>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function deleteUsers($users) {
+      $count = 0;
+
+      if($this->_openDB()) {
+        if (is_array($users) && count($users)) {
+          $this->_lockTables("WRITE");
+          foreach ($users as $user) {
+            if ($this->_delUser($user))
+              $count++;
+          }
+          $this->_unlockTables();
+        }
+        $this->_closeDB();
+      }
+      return $count;
+    }
+
+    /**
+     * [public function]
+     *
+     * Counts users which meet certain $filter criteria.
+     *
+     * @param  array  $filter  filter criteria in item/pattern pairs
+     * @return count of found users.
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function getUserCount($filter=array()) {
+      $rc = 0;
+
+      if($this->_openDB()) {
+        $sql = $this->_createSQLFilter($this->cnf['getUsers'], $filter);
+
+        if ($this->dbver >= 4) {
+          $sql = substr($sql, 6);  /* remove 'SELECT' or 'select' */
+          $sql = "SELECT SQL_CALC_FOUND_ROWS".$sql." LIMIT 1";
+          $this->_queryDB($sql);
+          $result = $this->_queryDB("SELECT FOUND_ROWS()");
+          $rc = $result[0]['FOUND_ROWS()'];
+        } else if (($result = $this->_queryDB($sql)))
+          $rc = count($result);
+
+        $this->_closeDB();
+      }
+      return $rc;
+    }
+
+    /**
+     * Bulk retrieval of user data. [public function]
+     *
+     * @param   first     index of first user to be returned
+     * @param   limit     max number of users to be returned
+     * @param   filter    array of field/pattern pairs
+     * @return  array of userinfo (refer getUserData for internal userinfo details)
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function retrieveUsers($first=0,$limit=10,$filter=array()) {
+      $out   = array();
+
+      if($this->_openDB()) {
+        $this->_lockTables("READ");
+        $sql  = $this->_createSQLFilter($this->cnf['getUsers'], $filter);
+        $sql .= " ".$this->cnf['SortOrder']." LIMIT $first, $limit";
+        $result = $this->_queryDB($sql);
+
+        if (!empty($result)) {
+          foreach ($result as $user)
+            if (($info = $this->_getUserInfo($user['user'])))
+              $out[$user['user']] = $info;
+        }
+
+        $this->_unlockTables();
+        $this->_closeDB();
+      }
+      return $out;
+    }
+
+    /**
+     * Give user membership of a group [public function]
+     *
+     * @param   $user
+     * @param   $group
+     * @return  bool    true on success, false on error
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function joinGroup($user, $group) {
+      $rc = false;
+
+      if ($this->_openDB()) {
+        $this->_lockTables("WRITE");
+        $rc  = $this->_addUserToGroup($user, $group);
+        $this->_unlockTables();
+        $this->_closeDB();
+      }
+      return $rc;
+    }
+
+    /**
+     * Remove user from a group [public function]
+     *
+     * @param   $user    user that leaves a group
+     * @param   $group   group to leave
+     * @return  bool
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function leaveGroup($user, $group) {
+      $rc = false;
+
+      if ($this->_openDB()) {
+        $this->_lockTables("WRITE");
+        $uid = $this->_getUserID($user);
+        $rc  = $this->_delUserFromGroup($user, $group);
+        $this->_unlockTables();
+        $this->_closeDB();
+      }
+      return $rc;
+    }
+
+    /**
+     * MySQL is case-insensitive
+     */
+    function isCaseSensitive(){
+        return false;
+    }
+
+    /**
+     * Adds a user to a group.
+     *
+     * If $force is set to '1' non existing groups would be created.
+     *
+     * The database connection must already be established. Otherwise
+     * this function does nothing and returns 'false'. It is strongly
+     * recommended to call this function only after all participating
+     * tables (group and usergroup) have been locked.
+     *
+     * @param   $user    user to add to a group
+     * @param   $group   name of the group
+     * @param   $force   '1' create missing groups
+     * @return  bool     'true' on success, 'false' on error
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _addUserToGroup($user, $group, $force=0) {
+      $newgroup = 0;
+
+      if (($this->dbcon) && ($user)) {
+        $gid = $this->_getGroupID($group);
+        if (!$gid) {
+          if ($force) {  // create missing groups
+            $sql = str_replace('%{group}',$this->_escape($group),$this->cnf['addGroup']);
+            $gid = $this->_modifyDB($sql);
+            $newgroup = 1;  // group newly created
+          }
+          if (!$gid) return false; // group didn't exist and can't be created
+        }
+
+        $sql = $this->cnf['addUserGroup'];
+        if(strpos($sql,'%{uid}') !== false){
+            $uid = $this->_getUserID($user);
+            $sql = str_replace('%{uid}',  $this->_escape($uid),$sql);
+        }
+        $sql = str_replace('%{user}', $this->_escape($user),$sql);
+        $sql = str_replace('%{gid}',  $this->_escape($gid),$sql);
+        $sql = str_replace('%{group}',$this->_escape($group),$sql);
+        if ($this->_modifyDB($sql) !== false) return true;
+
+        if ($newgroup) { // remove previously created group on error
+          $sql = str_replace('%{gid}',  $this->_escape($gid),$this->cnf['delGroup']);
+          $sql = str_replace('%{group}',$this->_escape($group),$sql);
+          $this->_modifyDB($sql);
+        }
+      }
+      return false;
+    }
+
+    /**
+     * Remove user from a group
+     *
+     * @param   $user    user that leaves a group
+     * @param   $group   group to leave
+     * @return  bool     true on success, false on error
+     *
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _delUserFromGroup($user, $group) {
+      $rc = false;
+
+
+      if (($this->dbcon) && ($user)) {
+        $sql = $this->cnf['delUserGroup'];
+        if(strpos($sql,'%{uid}') !== false){
+            $uid = $this->_getUserID($user);
+            $sql = str_replace('%{uid}',  $this->_escape($uid),$sql);
+        }
+        $gid = $this->_getGroupID($group);
+        if ($gid) {
+          $sql = str_replace('%{user}', $this->_escape($user),$sql);
+          $sql = str_replace('%{gid}',  $this->_escape($gid),$sql);
+          $sql = str_replace('%{group}',$this->_escape($group),$sql);
+          $rc  = $this->_modifyDB($sql) == 0 ? true : false;
+        }
+      }
+      return $rc;
+    }
+
+    /**
+     * Retrieves a list of groups the user is a member off.
+     *
+     * The database connection must already be established
+     * for this function to work. Otherwise it will return
+     * 'false'.
+     *
+     * @param  $user  user whose groups should be listed
+     * @return bool   false on error
+     * @return array  array containing all groups on success
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _getGroups($user) {
+      $groups = array();
+
+      if($this->dbcon) {
+        $sql = str_replace('%{user}',$this->_escape($user),$this->cnf['getGroups']);
+        $result = $this->_queryDB($sql);
+
+        if($result !== false && count($result)) {
+          foreach($result as $row)
+            $groups[] = $row['group'];
+        }
+        return $groups;
+      }
+      return false;
+    }
+
+    /**
+     * Retrieves the user id of a given user name
+     *
+     * The database connection must already be established
+     * for this function to work. Otherwise it will return
+     * 'false'.
+     *
+     * @param  $user   user whose id is desired
+     * @return user id
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _getUserID($user) {
+      if($this->dbcon) {
+        $sql = str_replace('%{user}',$this->_escape($user),$this->cnf['getUserID']);
+        $result = $this->_queryDB($sql);
+        return $result === false ? false : $result[0]['id'];
+      }
+      return false;
+    }
+
+    /**
+     * Adds a new User to the database.
+     *
+     * The database connection must already be established
+     * for this function to work. Otherwise it will return
+     * 'false'.
+     *
+     * @param  $user  login of the user
+     * @param  $pwd   encrypted password
+     * @param  $name  full name of the user
+     * @param  $mail  email address
+     * @param  $grps  array of groups the user should become member of
+     * @return bool
+     *
+     * @author  Andreas Gohr <andi@splitbrain.org>
+     * @author  Chris Smith <chris@jalakai.co.uk>
+     * @author  Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _addUser($user,$pwd,$name,$mail,$grps){
+      if($this->dbcon && is_array($grps)) {
+        $sql = str_replace('%{user}', $this->_escape($user),$this->cnf['addUser']);
+        $sql = str_replace('%{pass}', $this->_escape($pwd),$sql);
+        $sql = str_replace('%{name}', $this->_escape($name),$sql);
+        $sql = str_replace('%{email}',$this->_escape($mail),$sql);
+        $uid = $this->_modifyDB($sql);
+
+        if ($uid) {
+          foreach($grps as $group) {
+            $gid = $this->_addUserToGroup($user, $group, 1);
+            if ($gid === false) break;
+          }
+
+          if ($gid) return true;
+          else {
+            /* remove the new user and all group relations if a group can't
+             * be assigned. Newly created groups will remain in the database
+             * and won't be removed. This might create orphaned groups but
+             * is not a big issue so we ignore this problem here.
+             */
+            $this->_delUser($user);
+            if ($this->cnf['debug'])
+              msg ("MySQL err: Adding user '$user' to group '$group' failed.",-1,__LINE__,__FILE__);
+          }
+        }
+      }
+      return false;
+    }
+
+    /**
+     * Deletes a given user and all his group references.
+     *
+     * The database connection must already be established
+     * for this function to work. Otherwise it will return
+     * 'false'.
+     *
+     * @param  $user   user whose id is desired
+     * @return bool
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _delUser($user) {
+      if($this->dbcon) {
+        $uid = $this->_getUserID($user);
+        if ($uid) {
+          $sql = str_replace('%{uid}',$this->_escape($uid),$this->cnf['delUserRefs']);
+          $this->_modifyDB($sql);
+          $sql = str_replace('%{uid}',$this->_escape($uid),$this->cnf['delUser']);
+          $sql = str_replace('%{user}',  $this->_escape($user),$sql);
+          $this->_modifyDB($sql);
+          return true;
+        }
+      }
+      return false;
+    }
+
+    /**
+     * getUserInfo
+     *
+     * Gets the data for a specific user The database connection
+     * must already be established for this function to work.
+     * Otherwise it will return 'false'.
+     *
+     * @param  $user  user's nick to get data for
+     * @return bool   false on error
+     * @return array  user info on success
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _getUserInfo($user){
+      $sql = str_replace('%{user}',$this->_escape($user),$this->cnf['getUserInfo']);
+      $result = $this->_queryDB($sql);
+      if($result !== false && count($result)) {
+        $info = $result[0];
+        $info['grps'] = $this->_getGroups($user);
+        return $info;
+      }
+      return false;
+    }
+
+    /**
+     * Updates the user info in the database
+     *
+     * Update a user data structure in the database according changes
+     * given in an array. The user name can only be changes if it didn't
+     * exists already. If the new user name exists the update procedure
+     * will be aborted. The database keeps unchanged.
+     *
+     * The database connection has already to be established for this
+     * function to work. Otherwise it will return 'false'.
+     *
+     * The password will be crypted if necessary.
+     *
+     * @param  $changes  array of items to change as pairs of item and value
+     * @param  $uid      user id of dataset to change, must be unique in DB
+     * @return true on success or false on error
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _updateUserInfo($changes, $uid) {
+      $sql  = $this->cnf['updateUser']." ";
+      $cnt = 0;
+      $err = 0;
+
+      if($this->dbcon) {
+        foreach ($changes as $item => $value) {
+          if ($item == 'user') {
+            if (($this->_getUserID($changes['user']))) {
+              $err = 1; /* new username already exists */
+              break;    /* abort update */
+            }
+            if ($cnt++ > 0) $sql .= ", ";
+            $sql .= str_replace('%{user}',$value,$this->cnf['UpdateLogin']);
+          } else if ($item == 'name') {
+            if ($cnt++ > 0) $sql .= ", ";
+            $sql .= str_replace('%{name}',$value,$this->cnf['UpdateName']);
+          } else if ($item == 'pass') {
+            if (!$this->cnf['forwardClearPass'])
+              $value = auth_cryptPassword($value);
+            if ($cnt++ > 0) $sql .= ", ";
+            $sql .= str_replace('%{pass}',$value,$this->cnf['UpdatePass']);
+          } else if ($item == 'mail') {
+            if ($cnt++ > 0) $sql .= ", ";
+            $sql .= str_replace('%{email}',$value,$this->cnf['UpdateEmail']);
+          }
+        }
+
+        if ($err == 0) {
+          if ($cnt > 0) {
+            $sql .= " ".str_replace('%{uid}', $uid, $this->cnf['UpdateTarget']);
+            if(get_class($this) == 'auth_mysql') $sql .= " LIMIT 1"; //some PgSQL inheritance comp.
+            $this->_modifyDB($sql);
+          }
+          return true;
+        }
+      }
+      return false;
+    }
+
+    /**
+     * Retrieves the group id of a given group name
+     *
+     * The database connection must already be established
+     * for this function to work. Otherwise it will return
+     * 'false'.
+     *
+     * @param  $group   group name which id is desired
+     * @return group id
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _getGroupID($group) {
+      if($this->dbcon) {
+        $sql = str_replace('%{group}',$this->_escape($group),$this->cnf['getGroupID']);
+        $result = $this->_queryDB($sql);
+        return $result === false ? false : $result[0]['id'];
+      }
+      return false;
+    }
+
+    /**
+     * Opens a connection to a database and saves the handle for further
+     * usage in the object. The successful call to this functions is
+     * essential for most functions in this object.
+     *
+     * @return bool
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _openDB() {
+      if (!$this->dbcon) {
+        $con = @mysql_connect ($this->cnf['server'], $this->cnf['user'], $this->cnf['password']);
+        if ($con) {
+          if ((mysql_select_db($this->cnf['database'], $con))) {
+            if ((preg_match("/^(\d+)\.(\d+)\.(\d+).*/", mysql_get_server_info ($con), $result)) == 1) {
+              $this->dbver = $result[1];
+              $this->dbrev = $result[2];
+              $this->dbsub = $result[3];
+            }
+            $this->dbcon = $con;
+            if(!empty($this->cnf['charset'])){
+                 mysql_query('SET CHARACTER SET "' . $this->cnf['charset'] . '"', $con);
+            }
+            return true;   // connection and database successfully opened
+          } else {
+            mysql_close ($con);
+            if ($this->cnf['debug'])
+              msg("MySQL err: No access to database {$this->cnf['database']}.",-1,__LINE__,__FILE__);
+          }
+        } else if ($this->cnf['debug'])
+          msg ("MySQL err: Connection to {$this->cnf['user']}@{$this->cnf['server']} not possible.",
+               -1,__LINE__,__FILE__);
+
+        return false;  // connection failed
+      }
+      return true;  // connection already open
+    }
+
+    /**
+     * Closes a database connection.
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _closeDB() {
+      if ($this->dbcon) {
+        mysql_close ($this->dbcon);
+        $this->dbcon = 0;
+      }
+    }
+
+    /**
+     * Sends a SQL query to the database and transforms the result into
+     * an associative array.
+     *
+     * This function is only able to handle queries that returns a
+     * table such as SELECT.
+     *
+     * @param $query  SQL string that contains the query
+     * @return array with the result table
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _queryDB($query) {
+      if($this->cnf['debug'] >= 2){
+        msg('MySQL query: '.hsc($query),0,__LINE__,__FILE__);
+      }
+
+      $resultarray = array();
+      if ($this->dbcon) {
+        $result = @mysql_query($query,$this->dbcon);
+        if ($result) {
+          while (($t = mysql_fetch_assoc($result)) !== false)
+            $resultarray[]=$t;
+          mysql_free_result ($result);
+          return $resultarray;
+        }
+        if ($this->cnf['debug'])
+          msg('MySQL err: '.mysql_error($this->dbcon),-1,__LINE__,__FILE__);
+      }
+      return false;
+    }
+
+    /**
+     * Sends a SQL query to the database
+     *
+     * This function is only able to handle queries that returns
+     * either nothing or an id value such as INPUT, DELETE, UPDATE, etc.
+     *
+     * @param $query  SQL string that contains the query
+     * @return insert id or 0, false on error
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _modifyDB($query) {
+      if ($this->dbcon) {
+        $result = @mysql_query($query,$this->dbcon);
+        if ($result) {
+          $rc = mysql_insert_id($this->dbcon); //give back ID on insert
+          if ($rc !== false) return $rc;
+        }
+        if ($this->cnf['debug'])
+          msg('MySQL err: '.mysql_error($this->dbcon),-1,__LINE__,__FILE__);
+      }
+      return false;
+    }
+
+    /**
+     * Locked a list of tables for exclusive access so that modifications
+     * to the database can't be disturbed by other threads. The list
+     * could be set with $conf['auth']['mysql']['TablesToLock'] = array()
+     *
+     * If aliases for tables are used in SQL statements, also this aliases
+     * must be locked. For eg. you use a table 'user' and the alias 'u' in
+     * some sql queries, the array must looks like this (order is important):
+     *   array("user", "user AS u");
+     *
+     * MySQL V3 is not able to handle transactions with COMMIT/ROLLBACK
+     * so that this functionality is simulated by this function. Nevertheless
+     * it is not as powerful as transactions, it is a good compromise in safty.
+     *
+     * @param $mode  could be 'READ' or 'WRITE'
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _lockTables($mode) {
+      if ($this->dbcon) {
+        if (is_array($this->cnf['TablesToLock']) && !empty($this->cnf['TablesToLock'])) {
+          if ($mode == "READ" || $mode == "WRITE") {
+            $sql = "LOCK TABLES ";
+            $cnt = 0;
+            foreach ($this->cnf['TablesToLock'] as $table) {
+              if ($cnt++ != 0) $sql .= ", ";
+              $sql .= "$table $mode";
+            }
+            $this->_modifyDB($sql);
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+
+    /**
+     * Unlock locked tables. All existing locks of this thread will be
+     * abrogated.
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _unlockTables() {
+      if ($this->dbcon) {
+        $this->_modifyDB("UNLOCK TABLES");
+        return true;
+      }
+      return false;
+    }
+
+    /**
+     * Transforms the filter settings in an filter string for a SQL database
+     * The database connection must already be established, otherwise the
+     * original SQL string without filter criteria will be returned.
+     *
+     * @param  $sql     SQL string to which the $filter criteria should be added
+     * @param  $filter  array of filter criteria as pairs of item and pattern
+     * @return SQL string with attached $filter criteria on success
+     * @return the original SQL string on error.
+     *
+     * @author Matthias Grimm <matthiasgrimm@users.sourceforge.net>
+     */
+    function _createSQLFilter($sql, $filter) {
+      $SQLfilter = "";
+      $cnt = 0;
+
+      if ($this->dbcon) {
+        foreach ($filter as $item => $pattern) {
+          $tmp = '%'.$this->_escape($pattern).'%';
+          if ($item == 'user') {
+            if ($cnt++ > 0) $SQLfilter .= " AND ";
+            $SQLfilter .= str_replace('%{user}',$tmp,$this->cnf['FilterLogin']);
+          } else if ($item == 'name') {
+            if ($cnt++ > 0) $SQLfilter .= " AND ";
+            $SQLfilter .= str_replace('%{name}',$tmp,$this->cnf['FilterName']);
+          } else if ($item == 'mail') {
+            if ($cnt++ > 0) $SQLfilter .= " AND ";
+            $SQLfilter .= str_replace('%{email}',$tmp,$this->cnf['FilterEmail']);
+          } else if ($item == 'grps') {
+            if ($cnt++ > 0) $SQLfilter .= " AND ";
+            $SQLfilter .= str_replace('%{group}',$tmp,$this->cnf['FilterGroup']);
+          }
+        }
+
+        // we have to check SQLfilter here and must not use $cnt because if
+        // any of cnf['Filter????'] is not defined, a malformed SQL string
+        // would be generated.
+
+        if (strlen($SQLfilter)) {
+          $glue = strpos(strtolower($sql),"where") ? " AND " : " WHERE ";
+          $sql = $sql.$glue.$SQLfilter;
+        }
+      }
+
+      return $sql;
+    }
+
+    /**
+     * Escape a string for insertion into the database
+     *
+     * @author Andreas Gohr <andi@splitbrain.org>
+     * @param  string  $string The string to escape
+     * @param  boolean $like   Escape wildcard chars as well?
+     */
+    function _escape($string,$like=false){
+      if($this->dbcon){
+        $string = mysql_real_escape_string($string, $this->dbcon);
+      }else{
+        $string = addslashes($string);
+      }
+      if($like){
+        $string = addcslashes($string,'%_');
+      }
+      return $string;
+    }
+}
+
+//Setup VIM: ex: et ts=2 enc=utf-8 :