/*
 * Copyright (C) 2014 ~ 2018 Deepin Technology Co., Ltd.
 *
 * Author:     jouyouyun <jouyouwen717@gmail.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package dbus

import (
	"encoding/hex"
)

// AuthExternal returns an Auth that authenticates as the given user with the
// EXTERNAL mechanism.
func AuthExternal(user string) Auth {
	return authExternal{user}
}

// AuthExternal implements the EXTERNAL authentication mechanism.
type authExternal struct {
	user string
}

func (a authExternal) FirstData() ([]byte, []byte, AuthStatus) {
	b := make([]byte, 2*len(a.user))
	hex.Encode(b, []byte(a.user))
	return []byte("EXTERNAL"), b, AuthOk
}

func (a authExternal) HandleData(b []byte) ([]byte, AuthStatus) {
	return nil, AuthError
}
