SFTP-based VPN bootstrapping with automatic collision-free IPs assignment/peers' public data sharing

[ST]

Hi Jason,

On Mon, 2018-04-16 at 00:37 +0200, Jason A. Donenfeld wrote:
> Hi ST,
> 
> It's a cool idea using the file system like that (the sticky bit would
> make the permissions part work correctly, perhaps), though I wonder if
> it's a bit complicated. If the model you're after is simply "server
> allocates IPs for peers already known through some channel but with
> unknown wireguard public keys", then maybe a better SSH-based
> interface is a special user that is only allowed to run one program,
> and that program does one thing: accepts as input a public key, and
> outputs [without races] an allocated IP, endpoint, and the server's
> public key. Under the hood that information could be stored in a
> variety of ways. Alternatively, this could be its own protocol over
> the wire or over TLS or over whatever the pre-established trust
> mechanism is that the idea is based on. One of the earliest dirty bash
> scripts for WireGuard did this (insecurely) over TCP --
> https://git.zx2c4.com/WireGuard/tree/contrib/examples/ncat-client-server/server.sh
> -- this is what's running on demo.wireguard.com.

I looked into those scripts - thank you! What discourages me is its
warning not to use in production! So I'm wondering maybe it is possible
to just use DHCP server/client somehow with WG for this purpose? Are
there any expected pitfalls for such a configuration? 

Thank you!