Re: [Curdle] SSH/QUIC draft

[Benjamin Kaduk <[e-mail]>]

On Sat, Jul 11, 2020 at 09:02:50PM -0500, denis bider wrote:
> Ilari:
> 
> 
> > I presume server authentication should be done using the TLS server
> certificate.
> 
> Server authentication needs to happen using existing SSH host keys with no
> change for users. Users should be able to update to new SSH software
> versions that support SSH/QUIC and everything should work out of the box
> without the user noticing a difference. Server admins may need to open a
> UDP port in the firewall, and that's it.
[...]
> 
> > For client authentication, one probably should use SSH-layer mechanisms
> 
> For client authentication, we use the exact same mechanisms currently used
> in SSH.  Anything less than "no change for the user" does not fly.

I'd be interested in hearing what (if anything) Ilari has to say about the
potential for cross-protocol attacks when reusing ssh host and client keys
for this related-but-not-exactly-the-same protocol.  On the face of it it
seems like something that "requires careful analysis" and quickly skimming
draft-bider-ssh-quic didn't give me enough context to be able to say
anything useful.

-Ben