function init_plugin($authtype) {
        $this->pluginconfig = 'auth_'.$authtype;
        $this->config = get_config($this->pluginconfig);
        if (empty($this->config->ldapencoding)) {
            $this->config->ldapencoding = 'utf-8';
        }
        if (empty($this->config->user_type)) {
            $this->config->user_type = 'default';
        }

        $ldap_usertypes = ldap_supported_usertypes();
        $this->config->user_type_name = $ldap_usertypes[$this->config->user_type];
        unset($ldap_usertypes);

        $default = ldap_getdefaults();

        // Use defaults if values not given
        foreach ($default as $key => $value) {
            // watch out - 0, false are correct values too
            if (!isset($this->config->{$key}) or $this->config->{$key} == '') {
                $this->config->{$key} = $value[$this->config->user_type];
            }
        }

        // Hack prefix to objectclass
        $this->config->objectclass = ldap_normalise_objectclass($this->config->objectclass);
    }