[PATCH] Respect WG protocol reserved bytes

[Aaron Jones]

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

-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://lists.zx2c4.com/pipermail/wireguard/attachments/20210317/c7db4502/attachment.sig>