Adding upstream version 2.11.4.upstream/2.11.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1513 insertions, 0 deletions

diff --git a/library/Icinga/Authentication/UserGroup/DbUserGroupBackend.php b/library/Icinga/Authentication/UserGroup/DbUserGroupBackend.php
new file mode 100644
index 0000000..66db97f
--- /dev/null
+++ b/library/Icinga/Authentication/UserGroup/DbUserGroupBackend.php
@@ -0,0 +1,325 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Authentication\UserGroup;
+
+use Exception;
+use Icinga\Data\Filter\Filter;
+use Icinga\Data\Inspectable;
+use Icinga\Data\Inspection;
+use Icinga\Exception\NotFoundError;
+use Icinga\Repository\DbRepository;
+use Icinga\Repository\RepositoryQuery;
+use Icinga\User;
+
+class DbUserGroupBackend extends DbRepository implements Inspectable, UserGroupBackendInterface
+{
+    /**
+     * The query columns being provided
+     *
+     * @var array
+     */
+    protected $queryColumns = array(
+        'group' => array(
+            'group_id'      => 'g.id',
+            'group'         => 'g.name COLLATE utf8mb4_general_ci',
+            'group_name'    => 'g.name',
+            'parent'        => 'g.parent',
+            'created_at'    => 'UNIX_TIMESTAMP(g.ctime)',
+            'last_modified' => 'UNIX_TIMESTAMP(g.mtime)'
+        ),
+        'group_membership' => array(
+            'group_id'      => 'gm.group_id',
+            'user'          => 'gm.username COLLATE utf8mb4_general_ci',
+            'user_name'     => 'gm.username',
+            'created_at'    => 'UNIX_TIMESTAMP(gm.ctime)',
+            'last_modified' => 'UNIX_TIMESTAMP(gm.mtime)'
+        )
+    );
+
+    /**
+     * The table aliases being applied
+     *
+     * @var array
+     */
+    protected $tableAliases = array(
+        'group'             => 'g',
+        'group_membership'  => 'gm'
+    );
+
+    /**
+     * The statement columns being provided
+     *
+     * @var array
+     */
+    protected $statementColumns = array(
+        'group' => array(
+            'group_id'      => 'id',
+            'group_name'    => 'name',
+            'parent'        => 'parent',
+            'created_at'    => 'ctime',
+            'last_modified' => 'mtime'
+        ),
+        'group_membership' => array(
+            'group_id'      => 'group_id',
+            'group_name'    => 'group_id',
+            'user_name'     => 'username',
+            'created_at'    => 'ctime',
+            'last_modified' => 'mtime'
+        )
+    );
+
+    /**
+     * The columns which are not permitted to be queried
+     *
+     * @var array
+     */
+    protected $blacklistedQueryColumns = array('group', 'user');
+
+    /**
+     * The search columns being provided
+     *
+     * @var array
+     */
+    protected $searchColumns = array('group', 'user');
+
+    /**
+     * The value conversion rules to apply on a query or statement
+     *
+     * @var array
+     */
+    protected $conversionRules = array(
+        'group'             => array(
+            'parent'        => 'group_id'
+        ),
+        'group_membership'  => array(
+            'group_name'    => 'group_id'
+        )
+    );
+
+    /**
+     * Initialize this database user group backend
+     */
+    protected function init()
+    {
+        if (! $this->ds->getTablePrefix()) {
+            $this->ds->setTablePrefix('icingaweb_');
+        }
+    }
+
+    /**
+     * Initialize this repository's filter columns
+     *
+     * @return  array
+     */
+    protected function initializeFilterColumns()
+    {
+        $userLabel = t('Username') . ' ' . t('(Case insensitive)');
+        $groupLabel = t('User Group') . ' ' . t('(Case insensitive)');
+        return array(
+            $userLabel          => 'user',
+            t('Username')       => 'user_name',
+            $groupLabel         => 'group',
+            t('User Group')     => 'group_name',
+            t('Parent')         => 'parent',
+            t('Created At')     => 'created_at',
+            t('Last modified')  => 'last_modified'
+        );
+    }
+
+    /**
+     * Insert a table row with the given data
+     *
+     * @param   string  $table
+     * @param   array   $bind
+     */
+    public function insert($table, array $bind, array $types = array())
+    {
+        $bind['created_at'] = date('Y-m-d H:i:s');
+        parent::insert($table, $bind);
+    }
+
+    /**
+     * Update table rows with the given data, optionally limited by using a filter
+     *
+     * @param   string  $table
+     * @param   array   $bind
+     * @param   Filter  $filter
+     */
+    public function update($table, array $bind, Filter $filter = null, array $types = array())
+    {
+        $bind['last_modified'] = date('Y-m-d H:i:s');
+        parent::update($table, $bind, $filter);
+    }
+
+    /**
+     * Delete table rows, optionally limited by using a filter
+     *
+     * @param   string  $table
+     * @param   Filter  $filter
+     */
+    public function delete($table, Filter $filter = null)
+    {
+        if ($table === 'group') {
+            parent::delete('group_membership', $filter);
+            $idQuery = $this->select(array('group_id'));
+            if ($filter !== null) {
+                $idQuery->applyFilter($filter);
+            }
+
+            $this->update('group', array('parent' => null), Filter::where('parent', $idQuery->fetchColumn()));
+        }
+
+        parent::delete($table, $filter);
+    }
+
+    /**
+     * Return the groups the given user is a member of
+     *
+     * @param   User    $user
+     *
+     * @return  array
+     */
+    public function getMemberships(User $user)
+    {
+        $groupQuery = $this->ds
+            ->select()
+            ->from(
+                array('g' => $this->prependTablePrefix('group')),
+                array(
+                    'group_name'    => 'g.name',
+                    'parent_name'   => 'gg.name'
+                )
+            )->joinLeft(
+                array('gg' => $this->prependTablePrefix('group')),
+                'g.parent = gg.id',
+                array()
+            );
+
+        $groups = array();
+        foreach ($groupQuery as $group) {
+            $groups[$group->group_name] = $group->parent_name;
+        }
+
+        $membershipQuery = $this
+            ->select()
+            ->from('group_membership', array('group_name'))
+            ->where('user_name', $user->getUsername());
+
+        $memberships = array();
+        foreach ($membershipQuery as $membership) {
+            $memberships[] = $membership->group_name;
+            $parent = $groups[$membership->group_name];
+            while ($parent !== null) {
+                $memberships[] = $parent;
+                // Usually a parent is an existing group, but since we do not have a constraint on our table..
+                $parent = isset($groups[$parent]) ? $groups[$parent] : null;
+            }
+        }
+
+        return $memberships;
+    }
+
+    /**
+     * Return the name of the backend that is providing the given user
+     *
+     * @param   string  $username   Currently unused
+     *
+     * @return  null|string     The name of the backend or null in case this information is not available
+     */
+    public function getUserBackendName($username)
+    {
+        return null; // TODO(10373): Store this to the database when inserting and fetch it here
+    }
+
+    /**
+     * Join group into group_membership
+     *
+     * @param   RepositoryQuery     $query
+     */
+    protected function joinGroup(RepositoryQuery $query)
+    {
+        $query->getQuery()->join(
+            $this->requireTable('group'),
+            'gm.group_id = g.id',
+            array()
+        );
+    }
+
+    /**
+     * Join group_membership into group
+     *
+     * @param   RepositoryQuery     $query
+     */
+    protected function joinGroupMembership(RepositoryQuery $query)
+    {
+        $query->getQuery()->joinLeft(
+            $this->requireTable('group_membership'),
+            'g.id = gm.group_id',
+            array()
+        )->group('g.id');
+    }
+
+    /**
+     * Fetch and return the corresponding id for the given group's name
+     *
+     * @param   string|array    $groupName
+     *
+     * @return  int
+     *
+     * @throws  NotFoundError
+     */
+    protected function persistGroupId($groupName)
+    {
+        if (! $groupName || empty($groupName) || is_numeric($groupName)) {
+            return $groupName;
+        }
+
+        if (is_array($groupName)) {
+            if (is_numeric($groupName[0])) {
+                return $groupName; // In case the array contains mixed types...
+            }
+
+            $groupIds = $this->ds
+                ->select()
+                ->from($this->prependTablePrefix('group'), array('id'))
+                ->where('name', $groupName)
+                ->fetchColumn();
+            if (empty($groupIds)) {
+                throw new NotFoundError('No groups found matching one of: %s', implode(', ', $groupName));
+            }
+
+            return $groupIds;
+        }
+
+        $groupId = $this->ds
+            ->select()
+            ->from($this->prependTablePrefix('group'), array('id'))
+            ->where('name', $groupName)
+            ->fetchOne();
+        if ($groupId === false) {
+            throw new NotFoundError('Group "%s" does not exist', $groupName);
+        }
+
+        return $groupId;
+    }
+
+    /**
+     * Inspect this object to gain extended information about its health
+     *
+     * @return Inspection           The inspection result
+     */
+    public function inspect()
+    {
+        $insp = new Inspection('Db User Group Backend');
+        $insp->write($this->ds->inspect());
+
+        try {
+            $insp->write(sprintf('%s group(s)', $this->select()->count()));
+        } catch (Exception $e) {
+            $insp->error(sprintf('Query failed: %s', $e->getMessage()));
+        }
+
+        return $insp;
+    }
+}
diff --git a/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php b/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php
new file mode 100644
index 0000000..54ccaa9
--- /dev/null
+++ b/library/Icinga/Authentication/UserGroup/LdapUserGroupBackend.php
@@ -0,0 +1,944 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Authentication\UserGroup;
+
+use Exception;
+use Icinga\Authentication\User\UserBackend;
+use Icinga\Authentication\User\LdapUserBackend;
+use Icinga\Application\Logger;
+use Icinga\Data\ConfigObject;
+use Icinga\Data\Inspectable;
+use Icinga\Data\Inspection;
+use Icinga\Exception\AuthenticationException;
+use Icinga\Exception\ConfigurationError;
+use Icinga\Exception\ProgrammingError;
+use Icinga\Protocol\Ldap\LdapException;
+use Icinga\Protocol\Ldap\LdapUtils;
+use Icinga\Repository\LdapRepository;
+use Icinga\Repository\RepositoryQuery;
+use Icinga\User;
+
+class LdapUserGroupBackend extends LdapRepository implements Inspectable, UserGroupBackendInterface
+{
+    /**
+     * The user backend being associated with this user group backend
+     *
+     * @var LdapUserBackend
+     */
+    protected $userBackend;
+
+    /**
+     * The base DN to use for a user query
+     *
+     * @var string
+     */
+    protected $userBaseDn;
+
+    /**
+     * The base DN to use for a group query
+     *
+     * @var string
+     */
+    protected $groupBaseDn;
+
+    /**
+     * The objectClass where look for users
+     *
+     * @var string
+     */
+    protected $userClass;
+
+    /**
+     * The objectClass where look for groups
+     *
+     * @var string
+     */
+    protected $groupClass;
+
+    /**
+     * The attribute name where to find a user's name
+     *
+     * @var string
+     */
+    protected $userNameAttribute;
+
+    /**
+     * The attribute name where to find a group's name
+     *
+     * @var string
+     */
+    protected $groupNameAttribute;
+
+    /**
+     * The attribute name where to find a group's member
+     *
+     * @var string
+     */
+    protected $groupMemberAttribute;
+
+    /**
+     * Whether the attribute name where to find a group's member holds ambiguous values
+     *
+     * @var bool
+     */
+    protected $ambiguousMemberAttribute;
+
+    /**
+     * The custom LDAP filter to apply on a user query
+     *
+     * @var string
+     */
+    protected $userFilter;
+
+    /**
+     * The custom LDAP filter to apply on a group query
+     *
+     * @var string
+     */
+    protected $groupFilter;
+
+    /**
+     * ActiveDirectory nested group on the user?
+     *
+     * @var bool
+     */
+    protected $nestedGroupSearch;
+
+    /**
+     * The domain the backend is responsible for
+     *
+     * @var string
+     */
+    protected $domain;
+
+    /**
+     * The columns which are not permitted to be queried
+     *
+     * @var array
+     */
+    protected $blacklistedQueryColumns = array('group', 'user');
+
+    /**
+     * The search columns being provided
+     *
+     * @var array
+     */
+    protected $searchColumns = array('group', 'user');
+
+    /**
+     * The default sort rules to be applied on a query
+     *
+     * @var array
+     */
+    protected $sortRules = array(
+        'group_name' => array(
+            'order' => 'asc'
+        )
+    );
+
+    /**
+     * Set the user backend to be associated with this user group backend
+     *
+     * @param   LdapUserBackend     $backend
+     *
+     * @return  $this
+     */
+    public function setUserBackend(LdapUserBackend $backend)
+    {
+        $this->userBackend = $backend;
+        return $this;
+    }
+
+    /**
+     * Return the user backend being associated with this user group backend
+     *
+     * @return  LdapUserBackend
+     */
+    public function getUserBackend()
+    {
+        return $this->userBackend;
+    }
+
+    /**
+     * Set the base DN to use for a user query
+     *
+     * @param   string  $baseDn
+     *
+     * @return  $this
+     */
+    public function setUserBaseDn($baseDn)
+    {
+        if ($baseDn && ($baseDn = trim($baseDn))) {
+            $this->userBaseDn = $baseDn;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Return the base DN to use for a user query
+     *
+     * @return  string
+     */
+    public function getUserBaseDn()
+    {
+        return $this->userBaseDn;
+    }
+
+    /**
+     * Set the base DN to use for a group query
+     *
+     * @param   string  $baseDn
+     *
+     * @return  $this
+     */
+    public function setGroupBaseDn($baseDn)
+    {
+        if ($baseDn && ($baseDn = trim($baseDn))) {
+            $this->groupBaseDn = $baseDn;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Return the base DN to use for a group query
+     *
+     * @return  string
+     */
+    public function getGroupBaseDn()
+    {
+        return $this->groupBaseDn;
+    }
+
+    /**
+     * Set the objectClass where to look for users
+     *
+     * @param   string  $userClass
+     *
+     * @return  $this
+     */
+    public function setUserClass($userClass)
+    {
+        $this->userClass = $this->getNormedAttribute($userClass);
+        return $this;
+    }
+
+    /**
+     * Return the objectClass where to look for users
+     *
+     * @return string
+     */
+    public function getUserClass()
+    {
+        return $this->userClass;
+    }
+
+    /**
+     * Set the objectClass where to look for groups
+     *
+     * @param   string  $groupClass
+     *
+     * @return  $this
+     */
+    public function setGroupClass($groupClass)
+    {
+        $this->groupClass = $this->getNormedAttribute($groupClass);
+        return $this;
+    }
+
+    /**
+     * Return the objectClass where to look for groups
+     *
+     * @return string
+     */
+    public function getGroupClass()
+    {
+        return $this->groupClass;
+    }
+
+    /**
+     * Set the attribute name where to find a user's name
+     *
+     * @param   string  $userNameAttribute
+     *
+     * @return  $this
+     */
+    public function setUserNameAttribute($userNameAttribute)
+    {
+        $this->userNameAttribute = $this->getNormedAttribute($userNameAttribute);
+        return $this;
+    }
+
+    /**
+     * Return the attribute name where to find a user's name
+     *
+     * @return  string
+     */
+    public function getUserNameAttribute()
+    {
+        return $this->userNameAttribute;
+    }
+
+    /**
+     * Set the attribute name where to find a group's name
+     *
+     * @param   string  $groupNameAttribute
+     *
+     * @return  $this
+     */
+    public function setGroupNameAttribute($groupNameAttribute)
+    {
+        $this->groupNameAttribute = $this->getNormedAttribute($groupNameAttribute);
+        return $this;
+    }
+
+    /**
+     * Return the attribute name where to find a group's name
+     *
+     * @return  string
+     */
+    public function getGroupNameAttribute()
+    {
+        return $this->groupNameAttribute;
+    }
+
+    /**
+     * Set the attribute name where to find a group's member
+     *
+     * @param   string  $groupMemberAttribute
+     *
+     * @return  $this
+     */
+    public function setGroupMemberAttribute($groupMemberAttribute)
+    {
+        $this->groupMemberAttribute = $this->getNormedAttribute($groupMemberAttribute);
+        return $this;
+    }
+
+    /**
+     * Return the attribute name where to find a group's member
+     *
+     * @return  string
+     */
+    public function getGroupMemberAttribute()
+    {
+        return $this->groupMemberAttribute;
+    }
+
+    /**
+     * Set the custom LDAP filter to apply on a user query
+     *
+     * @param   string  $filter
+     *
+     * @return  $this
+     */
+    public function setUserFilter($filter)
+    {
+        if ($filter && ($filter = trim($filter))) {
+            if ($filter[0] === '(') {
+                $filter = substr($filter, 1, -1);
+            }
+
+            $this->userFilter = $filter;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Return the custom LDAP filter to apply on a user query
+     *
+     * @return  string
+     */
+    public function getUserFilter()
+    {
+        return $this->userFilter;
+    }
+
+    /**
+     * Set the custom LDAP filter to apply on a group query
+     *
+     * @param   string  $filter
+     *
+     * @return  $this
+     */
+    public function setGroupFilter($filter)
+    {
+        if ($filter && ($filter = trim($filter))) {
+            $this->groupFilter = $filter;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Return the custom LDAP filter to apply on a group query
+     *
+     * @return  string
+     */
+    public function getGroupFilter()
+    {
+        return $this->groupFilter;
+    }
+
+    /**
+     * Set nestedGroupSearch for the group query
+     *
+     * @param   bool    $enable
+     *
+     * @return  $this
+     */
+    public function setNestedGroupSearch($enable = true)
+    {
+        $this->nestedGroupSearch = $enable;
+        return $this;
+    }
+
+    /**
+     * Get nestedGroupSearch for the group query
+     *
+     * @return bool
+     */
+    public function getNestedGroupSearch()
+    {
+        return $this->nestedGroupSearch;
+    }
+
+    /**
+     * Get the domain the backend is responsible for
+     *
+     * If the LDAP group backend is linked with a LDAP user backend,
+     * the domain of the user backend will be returned.
+     *
+     * @return string
+     */
+    public function getDomain()
+    {
+        return $this->userBackend !== null ? $this->userBackend->getDomain() : $this->domain;
+    }
+
+    /**
+     * Set the domain the backend is responsible for
+     *
+     * If the LDAP group backend is linked with a LDAP user backend,
+     * the domain of the user backend will be used nonetheless.
+     *
+     * @param   string  $domain
+     *
+     * @return  $this
+     */
+    public function setDomain($domain)
+    {
+        if ($domain && ($domain = trim($domain))) {
+            $this->domain = $domain;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Return whether the attribute name where to find a group's member holds ambiguous values
+     *
+     * This tries to detect if the member attribute of groups contain:
+     *
+     *  full DN -> distinguished name of another object
+     *  other   -> ambiguous field referencing the member by userNameAttribute
+     *
+     * @return  bool
+     *
+     * @throws  ProgrammingError    In case either $this->groupClass or $this->groupMemberAttribute
+     *                              has not been set yet
+     */
+    protected function isMemberAttributeAmbiguous()
+    {
+        if ($this->ambiguousMemberAttribute === null) {
+            if ($this->groupClass === null) {
+                throw new ProgrammingError(
+                    'It is required to set the objectClass where to look for groups first'
+                );
+            } elseif ($this->groupMemberAttribute === null) {
+                throw new ProgrammingError(
+                    'It is required to set a attribute name where to find a group\'s members first'
+                );
+            }
+
+            $sampleValues = $this->ds
+                ->select()
+                ->from($this->groupClass, array($this->groupMemberAttribute))
+                ->where($this->groupMemberAttribute, '*')
+                ->limit(Logger::getInstance()->getLevel() === Logger::DEBUG ? 3 : 1)
+                ->setUnfoldAttribute($this->groupMemberAttribute)
+                ->setBase($this->groupBaseDn)
+                ->fetchAll();
+
+            Logger::debug('Ambiguity query returned %d results', count($sampleValues));
+
+            $i = 0;
+            $sampleValue = null;
+            foreach ($sampleValues as $key => $value) {
+                if ($sampleValue === null) {
+                    $sampleValue = $value;
+                }
+
+                Logger::debug('Result %d: %s (%s)', ++$i, $value, $key);
+            }
+
+            if (is_object($sampleValue) && isset($sampleValue->{$this->groupMemberAttribute})) {
+                $this->ambiguousMemberAttribute = ! LdapUtils::isDn($sampleValue->{$this->groupMemberAttribute});
+
+                Logger::debug(
+                    'Ambiguity check came to the conclusion that the member attribute %s ambiguous. Tested sample: %s',
+                    $this->ambiguousMemberAttribute ? 'is' : 'is not',
+                    $sampleValue->{$this->groupMemberAttribute}
+                );
+            } else {
+                Logger::warning(
+                    'Ambiguity query returned zero or invalid results. Sample value is `%s`',
+                    print_r($sampleValue, true)
+                );
+            }
+        }
+
+        return $this->ambiguousMemberAttribute;
+    }
+
+    /**
+     * Initialize this repository's virtual tables
+     *
+     * @return  array
+     *
+     * @throws  ProgrammingError    In case $this->groupClass has not been set yet
+     */
+    protected function initializeVirtualTables()
+    {
+        if ($this->groupClass === null) {
+            throw new ProgrammingError('It is required to set the object class where to find groups first');
+        }
+
+        return array(
+            'group'             => $this->groupClass,
+            'group_membership'  => $this->groupClass
+        );
+    }
+
+    /**
+     * Initialize this repository's query columns
+     *
+     * @return  array
+     *
+     * @throws  ProgrammingError    In case either $this->groupNameAttribute or
+     *                              $this->groupMemberAttribute has not been set yet
+     */
+    protected function initializeQueryColumns()
+    {
+        if ($this->groupNameAttribute === null) {
+            throw new ProgrammingError('It is required to set a attribute name where to find a group\'s name first');
+        }
+        if ($this->groupMemberAttribute === null) {
+            throw new ProgrammingError('It is required to set a attribute name where to find a group\'s members first');
+        }
+
+        if ($this->ds->getCapabilities()->isActiveDirectory()) {
+            $createdAtAttribute = 'whenCreated';
+            $lastModifiedAttribute = 'whenChanged';
+        } else {
+            $createdAtAttribute = 'createTimestamp';
+            $lastModifiedAttribute = 'modifyTimestamp';
+        }
+
+        $columns = array(
+            'group'         => $this->groupNameAttribute,
+            'group_name'    => $this->groupNameAttribute,
+            'user'          => $this->groupMemberAttribute,
+            'user_name'     => $this->groupMemberAttribute,
+            'created_at'    => $createdAtAttribute,
+            'last_modified' => $lastModifiedAttribute
+        );
+        return array('group' => $columns, 'group_membership' => $columns);
+    }
+
+    /**
+     * Initialize this repository's filter columns
+     *
+     * @return  array
+     */
+    protected function initializeFilterColumns()
+    {
+        return array(
+            t('Username')       => 'user_name',
+            t('User Group')     => 'group_name',
+            t('Created At')     => 'created_at',
+            t('Last modified')  => 'last_modified'
+        );
+    }
+
+    /**
+     * Initialize this repository's conversion rules
+     *
+     * @return  array
+     */
+    protected function initializeConversionRules()
+    {
+        $rules = array(
+            'group' => array(
+                'created_at'    => 'generalized_time',
+                'last_modified' => 'generalized_time'
+            ),
+            'group_membership' => array(
+                'created_at'    => 'generalized_time',
+                'last_modified' => 'generalized_time'
+            )
+        );
+        if (! $this->isMemberAttributeAmbiguous()) {
+            $rules['group_membership']['user_name'] = 'user_name';
+            $rules['group_membership']['user'] = 'user_name';
+            $rules['group']['user_name'] = 'user_name';
+            $rules['group']['user'] = 'user_name';
+        }
+
+        return $rules;
+    }
+
+    /**
+     * Return the distinguished name for the given uid or gid
+     *
+     * @param   string  $name
+     *
+     * @return  string
+     */
+    protected function persistUserName($name)
+    {
+        try {
+            $userDn = $this->ds
+                ->select()
+                ->from($this->userClass, array())
+                ->where($this->userNameAttribute, $name)
+                ->setBase($this->userBaseDn)
+                ->setUsePagedResults(false)
+                ->fetchDn();
+            if ($userDn) {
+                return $userDn;
+            }
+
+            $groupDn = $this->ds
+                ->select()
+                ->from($this->groupClass, array())
+                ->where($this->groupNameAttribute, $name)
+                ->setBase($this->groupBaseDn)
+                ->setUsePagedResults(false)
+                ->fetchDn();
+            if ($groupDn) {
+                return $groupDn;
+            }
+        } catch (LdapException $_) {
+            // pass
+        }
+
+        Logger::debug('Unable to persist uid or gid "%s" in repository "%s". No DN found.', $name, $this->getName());
+        return $name;
+    }
+
+    /**
+     * Return the uid for the given distinguished name
+     *
+     * @param   string  $username
+     *
+     * @param   string
+     */
+    protected function retrieveUserName($dn)
+    {
+        return $this->ds
+            ->select()
+            ->from('*', array($this->userNameAttribute))
+            ->setUnfoldAttribute($this->userNameAttribute)
+            ->setBase($dn)
+            ->fetchOne();
+    }
+
+    /**
+     * Validate that the requested table exists
+     *
+     * @param   string              $table      The table to validate
+     * @param   RepositoryQuery     $query      An optional query to pass as context
+     *
+     * @return  string
+     *
+     * @throws  ProgrammingError                In case the given table does not exist
+     */
+    public function requireTable($table, RepositoryQuery $query = null)
+    {
+        if ($query !== null) {
+            $query->getQuery()->setBase($this->groupBaseDn);
+            if ($table === 'group' && $this->groupFilter) {
+                $query->getQuery()->setNativeFilter($this->groupFilter);
+            }
+        }
+
+        return parent::requireTable($table, $query);
+    }
+
+    /**
+     * Validate that the given column is a valid query target and return it or the actual name if it's an alias
+     *
+     * @param   string              $table  The table where to look for the column or alias
+     * @param   string              $name   The name or alias of the column to validate
+     * @param   RepositoryQuery     $query  An optional query to pass as context
+     *
+     * @return  string                      The given column's name
+     *
+     * @throws  QueryException              In case the given column is not a valid query column
+     */
+    public function requireQueryColumn($table, $name, RepositoryQuery $query = null)
+    {
+        $column = parent::requireQueryColumn($table, $name, $query);
+        if (($name === 'user_name' || $name === 'group_name') && $query !== null) {
+            $query->getQuery()->setUnfoldAttribute($name);
+        }
+
+        return $column;
+    }
+
+    /**
+     * Return the groups the given user is a member of
+     *
+     * @param   User    $user
+     *
+     * @return  array
+     */
+    public function getMemberships(User $user)
+    {
+        $domain = $this->getDomain();
+
+        if ($domain !== null) {
+            if (! $user->hasDomain() || strtolower($user->getDomain()) !== strtolower($domain)) {
+                return array();
+            }
+
+            $username = $user->getLocalUsername();
+        } else {
+            $username = $user->getUsername();
+        }
+
+        if ($this->isMemberAttributeAmbiguous()) {
+            $queryValue = $username;
+        } elseif (($queryValue = $user->getAdditional('ldap_dn')) === null) {
+            $userQuery = $this->ds
+                ->select()
+                ->from($this->userClass)
+                ->where($this->userNameAttribute, $username)
+                ->setBase($this->userBaseDn)
+                ->setUsePagedResults(false);
+            if ($this->userFilter) {
+                $userQuery->setNativeFilter($this->userFilter);
+            }
+
+            if (($queryValue = $userQuery->fetchDn()) === null) {
+                return array();
+            }
+        }
+
+        if ($this->nestedGroupSearch) {
+            $groupMemberAttribute = $this->groupMemberAttribute . ':1.2.840.113556.1.4.1941:';
+        } else {
+            $groupMemberAttribute = $this->groupMemberAttribute;
+        }
+
+        $groupQuery = $this->ds
+            ->select()
+            ->from($this->groupClass, array($this->groupNameAttribute))
+            ->setUnfoldAttribute($this->groupNameAttribute)
+            ->where($groupMemberAttribute, $queryValue)
+            ->setBase($this->groupBaseDn);
+        if ($this->groupFilter) {
+            $groupQuery->setNativeFilter($this->groupFilter);
+        }
+
+        $groups = array();
+        foreach ($groupQuery as $row) {
+            $groups[] = $row->{$this->groupNameAttribute};
+            if ($domain !== null) {
+                $groups[] = $row->{$this->groupNameAttribute} . "@$domain";
+            }
+        }
+
+        return $groups;
+    }
+
+    /**
+     * Return the name of the backend that is providing the given user
+     *
+     * @param   string  $username   Unused
+     *
+     * @return  null|string     The name of the backend or null in case this information is not available
+     */
+    public function getUserBackendName($username)
+    {
+        $userBackend = $this->getUserBackend();
+        if ($userBackend !== null) {
+            return $userBackend->getName();
+        }
+    }
+
+    /**
+     * Apply the given configuration on this backend
+     *
+     * @param   ConfigObject    $config
+     *
+     * @return  $this
+     *
+     * @throws  ConfigurationError      In case a linked user backend does not exist or is invalid
+     */
+    public function setConfig(ConfigObject $config)
+    {
+        if ($config->backend === 'ldap') {
+            $defaults = $this->getOpenLdapDefaults();
+        } elseif ($config->backend === 'msldap') {
+            $defaults = $this->getActiveDirectoryDefaults();
+        } else {
+            $defaults = new ConfigObject();
+        }
+
+        if ($config->user_backend && $config->user_backend !== 'none') {
+            $userBackend = UserBackend::create($config->user_backend);
+            if (! $userBackend instanceof LdapUserBackend) {
+                throw new ConfigurationError('User backend "%s" is not of type LDAP', $config->user_backend);
+            }
+
+            if ($this->ds->getHostname() !== $userBackend->getDataSource()->getHostname()
+                || $this->ds->getPort() !== $userBackend->getDataSource()->getPort()
+            ) {
+                // TODO(jom): Elaborate whether it makes sense to link directories on different hosts
+                throw new ConfigurationError(
+                    'It is required that a linked user backend refers to the '
+                    . 'same directory as it\'s user group backend counterpart'
+                );
+            }
+
+            $this->setUserBackend($userBackend);
+            $defaults->merge(array(
+                'user_base_dn'          => $userBackend->getBaseDn(),
+                'user_class'            => $userBackend->getUserClass(),
+                'user_name_attribute'   => $userBackend->getUserNameAttribute(),
+                'user_filter'           => $userBackend->getFilter(),
+                'domain'                => $userBackend->getDomain()
+            ));
+        }
+
+        return $this
+            ->setGroupBaseDn($config->base_dn)
+            ->setUserBaseDn($config->get('user_base_dn', $defaults->get('user_base_dn', $this->getGroupBaseDn())))
+            ->setGroupClass($config->get('group_class', $defaults->group_class))
+            ->setUserClass($config->get('user_class', $defaults->user_class))
+            ->setGroupNameAttribute($config->get('group_name_attribute', $defaults->group_name_attribute))
+            ->setUserNameAttribute($config->get('user_name_attribute', $defaults->user_name_attribute))
+            ->setGroupMemberAttribute($config->get('group_member_attribute', $defaults->group_member_attribute))
+            ->setGroupFilter($config->group_filter)
+            ->setUserFilter($config->user_filter)
+            ->setNestedGroupSearch((bool) $config->get('nested_group_search', $defaults->nested_group_search))
+            ->setDomain($defaults->get('domain', $config->domain));
+    }
+
+    /**
+     * Return the configuration defaults for an OpenLDAP environment
+     *
+     * @return  ConfigObject
+     */
+    public function getOpenLdapDefaults()
+    {
+        return new ConfigObject(array(
+            'group_class'               => 'group',
+            'user_class'                => 'inetOrgPerson',
+            'group_name_attribute'      => 'gid',
+            'user_name_attribute'       => 'uid',
+            'group_member_attribute'    => 'member',
+            'nested_group_search'       => '0'
+        ));
+    }
+
+    /**
+     * Return the configuration defaults for an ActiveDirectory environment
+     *
+     * @return  ConfigObject
+     */
+    public function getActiveDirectoryDefaults()
+    {
+        return new ConfigObject(array(
+            'group_class'               => 'group',
+            'user_class'                => 'user',
+            'group_name_attribute'      => 'sAMAccountName',
+            'user_name_attribute'       => 'sAMAccountName',
+            'group_member_attribute'    => 'member',
+            'nested_group_search'       => '0'
+        ));
+    }
+
+    /**
+     * Inspect if this LDAP User Group Backend is working as expected by probing the backend
+     *
+     * Try to bind to the backend and fetch a single group to check if:
+     * <ul>
+     *  <li>Connection credentials are correct and the bind is possible</li>
+     *  <li>At least one group exists</li>
+     *  <li>The specified groupClass has the property specified by groupNameAttribute</li>
+     * </ul>
+     *
+     * @return  Inspection  Inspection result
+     */
+    public function inspect()
+    {
+        $result = new Inspection('Ldap User Group Backend');
+
+        // inspect the used connection to get more diagnostic info in case the connection is not working
+        $result->write($this->ds->inspect());
+
+        try {
+            try {
+                $groupQuery = $this->ds
+                    ->select()
+                    ->from($this->groupClass, array($this->groupNameAttribute))
+                    ->setBase($this->groupBaseDn);
+
+                if ($this->groupFilter) {
+                    $groupQuery->setNativeFilter($this->groupFilter);
+                }
+
+                $res = $groupQuery->fetchRow();
+            } catch (LdapException $e) {
+                throw new AuthenticationException('Connection not possible', $e);
+            }
+
+            $result->write('Searching for: ' . sprintf(
+                'objectClass "%s" in DN "%s" (Filter: %s)',
+                $this->groupClass,
+                $this->groupBaseDn ?: $this->ds->getDn(),
+                $this->groupFilter ?: 'None'
+            ));
+
+            if ($res === false) {
+                throw new AuthenticationException('Error, no groups found in backend');
+            }
+
+            $result->write(sprintf('%d groups found in backend', $groupQuery->count()));
+
+            if (! isset($res->{$this->groupNameAttribute})) {
+                throw new AuthenticationException(
+                    'GroupNameAttribute "%s" not existing in objectClass "%s"',
+                    $this->groupNameAttribute,
+                    $this->groupClass
+                );
+            }
+        } catch (AuthenticationException $e) {
+            if (($previous = $e->getPrevious()) !== null) {
+                $result->error($previous->getMessage());
+            } else {
+                $result->error($e->getMessage());
+            }
+        } catch (Exception $e) {
+            $result->error(sprintf('Unable to validate backend: %s', $e->getMessage()));
+        }
+
+        return $result;
+    }
+}
diff --git a/library/Icinga/Authentication/UserGroup/UserGroupBackend.php b/library/Icinga/Authentication/UserGroup/UserGroupBackend.php
new file mode 100644
index 0000000..76fa2d0
--- /dev/null
+++ b/library/Icinga/Authentication/UserGroup/UserGroupBackend.php
@@ -0,0 +1,188 @@
+<?php
+/* Icinga Web 2 | (c) 2014 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Authentication\UserGroup;
+
+use Icinga\Application\Logger;
+use Icinga\Application\Icinga;
+use Icinga\Data\ConfigObject;
+use Icinga\Data\ResourceFactory;
+use Icinga\Exception\ConfigurationError;
+
+/**
+ * Factory for user group backends
+ */
+class UserGroupBackend
+{
+    /**
+     * The default user group backend types provided by Icinga Web 2
+     *
+     * @var array
+     */
+    protected static $defaultBackends = array(
+        'db',
+        'ldap',
+        'msldap'
+    );
+
+    /**
+     * The registered custom user group backends with their identifier as key and class name as value
+     *
+     * @var array
+     */
+    protected static $customBackends;
+
+    /**
+     * Register all custom user group backends from all loaded modules
+     */
+    public static function registerCustomUserGroupBackends()
+    {
+        if (static::$customBackends !== null) {
+            return;
+        }
+
+        static::$customBackends = array();
+        $providedBy = array();
+        foreach (Icinga::app()->getModuleManager()->getLoadedModules() as $module) {
+            foreach ($module->getUserGroupBackends() as $identifier => $className) {
+                if (array_key_exists($identifier, $providedBy)) {
+                    Logger::warning(
+                        'Cannot register user group backend of type "%s" provided by module "%s".'
+                        . ' The type is already provided by module "%s"',
+                        $identifier,
+                        $module->getName(),
+                        $providedBy[$identifier]
+                    );
+                } elseif (in_array($identifier, static::$defaultBackends)) {
+                    Logger::warning(
+                        'Cannot register user group backend of type "%s" provided by module "%s".'
+                        . ' The type is a default type provided by Icinga Web 2',
+                        $identifier,
+                        $module->getName()
+                    );
+                } else {
+                    $providedBy[$identifier] = $module->getName();
+                    static::$customBackends[$identifier] = $className;
+                }
+            }
+        }
+    }
+
+    /**
+     * Get config forms of all custom user group backends
+     */
+    public static function getCustomBackendConfigForms()
+    {
+        $customBackendConfigForms = [];
+        static::registerCustomUserGroupBackends();
+        foreach (self::$customBackends as $customBackendType => $customBackendClass) {
+            if (method_exists($customBackendClass, 'getConfigurationFormClass')) {
+                $customBackendConfigForms[$customBackendType] = $customBackendClass::getConfigurationFormClass();
+            }
+        }
+
+        return $customBackendConfigForms;
+    }
+
+    /**
+     * Return the class for the given custom user group backend
+     *
+     * @param   string  $identifier     The identifier of the custom user group backend
+     *
+     * @return  string|null             The name of the class or null in case there was no
+     *                                   backend found with the given identifier
+     *
+     * @throws  ConfigurationError      In case the class associated to the given identifier does not exist
+     */
+    protected static function getCustomUserGroupBackend($identifier)
+    {
+        static::registerCustomUserGroupBackends();
+        if (array_key_exists($identifier, static::$customBackends)) {
+            $className = static::$customBackends[$identifier];
+            if (! class_exists($className)) {
+                throw new ConfigurationError(
+                    'Cannot utilize user group backend of type "%s". Class "%s" does not exist',
+                    $identifier,
+                    $className
+                );
+            }
+
+            return $className;
+        }
+    }
+
+    /**
+     * Create and return a user group backend with the given name and given configuration applied to it
+     *
+     * @param   string          $name
+     * @param   ConfigObject    $backendConfig
+     *
+     * @return  UserGroupBackendInterface
+     *
+     * @throws  ConfigurationError
+     */
+    public static function create($name, ConfigObject $backendConfig)
+    {
+        if ($backendConfig->name !== null) {
+            $name = $backendConfig->name;
+        }
+
+        if (! ($backendType = strtolower($backendConfig->backend))) {
+            throw new ConfigurationError(
+                'Configuration for user group backend "%s" is missing the \'backend\' directive',
+                $name
+            );
+        }
+        if (in_array($backendType, static::$defaultBackends)) {
+            // The default backend check is the first one because of performance reasons:
+            // Do not attempt to load a custom user group backend unless it's actually required
+        } elseif (($customClass = static::getCustomUserGroupBackend($backendType)) !== null) {
+            $backend = new $customClass($backendConfig);
+            if (! is_a($backend, 'Icinga\Authentication\UserGroup\UserGroupBackendInterface')) {
+                throw new ConfigurationError(
+                    'Cannot utilize user group backend of type "%s".'
+                    . ' Class "%s" does not implement UserGroupBackendInterface',
+                    $backendType,
+                    $customClass
+                );
+            }
+
+            $backend->setName($name);
+            return $backend;
+        } else {
+            throw new ConfigurationError(
+                'Configuration for user group backend "%s" defines an invalid backend type.'
+                . ' Backend type "%s" is not supported',
+                $name,
+                $backendType
+            );
+        }
+
+        if ($backendConfig->resource === null) {
+            throw new ConfigurationError(
+                'Configuration for user group backend "%s" is missing the \'resource\' directive',
+                $name
+            );
+        }
+
+        $resourceConfig = ResourceFactory::getResourceConfig($backendConfig->resource);
+        if ($backendType === 'db' && $resourceConfig->db === 'mysql') {
+            $resourceConfig->charset = 'utf8mb4';
+        }
+
+        $resource = ResourceFactory::createResource($resourceConfig);
+        switch ($backendType) {
+            case 'db':
+                $backend = new DbUserGroupBackend($resource);
+                break;
+            case 'ldap':
+            case 'msldap':
+                $backend = new LdapUserGroupBackend($resource);
+                $backend->setConfig($backendConfig);
+                break;
+        }
+
+        $backend->setName($name);
+        return $backend;
+    }
+}
diff --git a/library/Icinga/Authentication/UserGroup/UserGroupBackendInterface.php b/library/Icinga/Authentication/UserGroup/UserGroupBackendInterface.php
new file mode 100644
index 0000000..cc9438f
--- /dev/null
+++ b/library/Icinga/Authentication/UserGroup/UserGroupBackendInterface.php
@@ -0,0 +1,56 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Authentication\UserGroup;
+
+use Icinga\User;
+
+/**
+ * Interface for user group backends
+ */
+interface UserGroupBackendInterface
+{
+    /**
+     * Set this backend's name
+     *
+     * @param   string  $name
+     *
+     * @return  $this
+     */
+    public function setName($name);
+
+    /**
+     * Return this backend's name
+     *
+     * @return  string
+     */
+    public function getName();
+
+    /**
+     * Return the groups the given user is a member of
+     *
+     * @param   User    $user
+     *
+     * @return  array
+     */
+    public function getMemberships(User $user);
+
+    /**
+     * Return the name of the backend that is providing the given user
+     *
+     * @param   string  $username
+     *
+     * @return  null|string     The name of the backend or null in case this information is not available
+     */
+    public function getUserBackendName($username);
+
+    /**
+     * Return this backend's configuration form class path
+     *
+     * This is not part of the interface to not break existing implementations.
+     * If you need a custom backend form, implement this method.
+     *
+     * @return string
+     */
+    //public static function getConfigurationFormClass();
+}