Overlapping AllowedIPs Configuration

[Toke Høiland-Jørgensen]

Paul Zillmann <paul at zil.li> writes:

> Hello,
>
> we have the same problem here, although our allowed IP ranges should be 
> 0.0.0.0/0 for all peers.
> We have OSPF traffic on the wireguard links so it should be task of the 
> Kernel's routing table to decide where to send what.
>
> The problem is that the allowed-ips configuration has multiple purposes: 
> routing table and firewall/packet filter. This introduces these 
> problems. It would be helpfull to get a compile flag or something else 
> to make this behavior optional.

That is probably not going to happen; the crypto-routing is quite
integral to Wireguard, and is an important security feature.

> Right now Wireguard isn't very friendly to dynamic routing.
>
> I came up with multiple solutions:
> - create multiple interfaces + tunnels.
> or
> - create a bash script that injects the Kernel's routing table into the 
> wg tool every other minute.
>
> Do you guys have a better idea? If not I would create the bash script.

IMO, the "right" way to fix this is to make your routing daemon aware of
wireguard and have it configure the routes directly into the wireguard
table. That also gives you security for your routing protocol
automatically (since only authenticated sources/destinations will be
allowed), as long as you have a secure way of bootstrapping the
wireguard keying.

-Toke