Re: [PATCH] Respect WG protocol reserved bytes

[Laura Zelenku <laura.zelenku@wandera.com>]

If the client send some data in reserved bytes you will have logs full of errors because the message gets type from 4 bytes instead of 1 byte (like it is in protocol description).
I would like implementation respects protocol - https://www.wireguard.com/papers/wireguard.pdf . Yes, in our project we use reserved bytes.

I know that when there are zeros in reserved bytes, everything is correct. But if you receive some non-zero value in reserved bytes?

Laura

> On 17. 3. 2021, at 13:35, Aaron Jones <me@aaronmdjones.net> wrote:
> 
> On 17/03/2021 07:55, Laura Zelenku wrote:
>> Packet that respects WG protocol contains Type on first byte followed by
>> three reserved bytes. Because wireguard-go implementation uses element
>> pools it is required to make sure that reserved bytes are cleared for
>> outgoing traffic (can get dirty by "bad" clients). Clearing reserved
>> bytes is also for backwards compatibility.
> 
> Encoding the message type as a little-endian 32-bit integer already
> takes care of setting the reserved bytes to zero; e.g. for a packet of
> message type 1 (handshake initiation), its little-endian 32-bit encoding
> is the following sequence of bytes: [ 0x01 0x00 0x00 0x00 ].
> 
> This is also the approach used for checking message types on the
> receiving end, so packets whose reserved bytes are non-zero are already
> discarded as being those of unknown types of message.
> 
> Regards,
> Aaron Jones
> 


-- 
*IMPORTANT NOTICE*: This email, its attachments and any rights attaching 
hereto are confidential and intended exclusively for the person to whom the 
email is addressed. If you are not the intended recipient, do not read, 
copy, disclose or use the contents in any way. Wandera accepts no liability 
for any loss, damage or consequence resulting directly or indirectly from 
the use of this email and attachments.