Removing expiry dates for TOFU

[Solderpunk]

On Mon Jul 6, 2020 at 12:18 AM CEST,  wrote:
> 5 year certs sound like a good compromise to me. We can make client
> messages sufficiently scary, seeing as a five year expiry will make
> TOFU issue somewhat rare. Will you set that as a default for your
> cert tool then?

Maybe! ;)  I *do* plan to finally start work on that tool this week, by
the way.

Hopefully by 2025 we'll have agreed on a way to do smooth roll-overs
which is widely implemented!  If that does happen, and it's easily
automated (which I'd very much like it to be), maybe we can start
shifting towards less long-lived keys/certs for a extra peace of mind.

> Do you agree with my original recommendation that clients should
> auto-accept any cert once the old one has expired? This seems relevant
> here. I think it's nice for UX, although I see the obvious security
> risk.

In the absence of any other roll-over mechanism, yeah, this seems like
sane behaviour for a TOFU client.

Cheers,
Solderpunk