protected function search($filter, $baseDn = null, $scope = Zend\Ldap\Ldap::SEARCH_SCOPE_SUB, $attributes = [], $sort = '')
    {
        $records = $this->ldap->search($filter, $baseDn, $scope, $attributes, $sort);

        $results = [];
        foreach ($records as $record) {
            foreach ($record as $attribute => $value) {
                // if the value is an array with a single value, e.g. 'samaccountname' => array(0 => 'myusername')
                // then make sure it's just set in the results as 'samaccountname' => 'myusername' so that it
                // can be used directly by ArrayData
                if (is_array($value) && count($value) == 1) {
                    $value = $value[0];
                }

                // ObjectGUID and ObjectSID attributes are in binary, we need to convert those to strings
                if ($attribute == 'objectguid') {
                    $value = LDAPUtil::bin_to_str_guid($value);
                }
                if ($attribute == 'objectsid') {
                    $value = LDAPUtil::bin_to_str_sid($value);
                }

                $record[$attribute] = $value;
            }

            $results[] = $record;
        }

        return $results;
    }