Пример #1
0
func getRequest(conn *ss.Conn, auth bool) (host string, ota bool, err error) {
	ss.SetReadTimeout(conn)

	// buf size should at least have the same size with the largest possible
	// request size (when addrType is 3, domain name has at most 256 bytes)
	// 1(addrType) + 1(lenByte) + 256(max length address) + 2(port) + 10(hmac-sha1)
	buf := make([]byte, 270)
	// read till we get possible domain length field
	if _, err = io.ReadFull(conn, buf[:idType+1]); err != nil {
		return
	}

	var reqStart, reqEnd int
	addrType := buf[idType]
	switch addrType & ss.AddrMask {
	case typeIPv4:
		reqStart, reqEnd = idIP0, idIP0+lenIPv4
	case typeIPv6:
		reqStart, reqEnd = idIP0, idIP0+lenIPv6
	case typeDm:
		if _, err = io.ReadFull(conn, buf[idType+1:idDmLen+1]); err != nil {
			return
		}
		reqStart, reqEnd = idDm0, int(idDm0+buf[idDmLen]+lenDmBase)
	default:
		err = fmt.Errorf("addr type %d not supported", addrType&ss.AddrMask)
		return
	}

	if _, err = io.ReadFull(conn, buf[reqStart:reqEnd]); err != nil {
		return
	}

	// Return string for typeIP is not most efficient, but browsers (Chrome,
	// Safari, Firefox) all seems using typeDm exclusively. So this is not a
	// big problem.
	switch addrType & ss.AddrMask {
	case typeIPv4:
		host = net.IP(buf[idIP0 : idIP0+net.IPv4len]).String()
	case typeIPv6:
		host = net.IP(buf[idIP0 : idIP0+net.IPv6len]).String()
	case typeDm:
		host = string(buf[idDm0 : idDm0+buf[idDmLen]])
	}
	// parse port
	port := binary.BigEndian.Uint16(buf[reqEnd-2 : reqEnd])
	host = net.JoinHostPort(host, strconv.Itoa(int(port)))
	// if specified one time auth enabled, we should verify this
	if auth || addrType&ss.OneTimeAuthMask > 0 {
		ota = true
		if _, err = io.ReadFull(conn, buf[reqEnd:reqEnd+lenHmacSha1]); err != nil {
			return
		}
		iv := conn.GetIv()
		key := conn.GetKey()
		actualHmacSha1Buf := ss.HmacSha1(append(iv, key...), buf[:reqEnd])
		if !bytes.Equal(buf[reqEnd:reqEnd+lenHmacSha1], actualHmacSha1Buf) {
			err = fmt.Errorf("verify one time auth failed, iv=%v key=%v data=%v", iv, key, buf[:reqEnd])
			return
		}
	}
	return
}