Re: [PATCH RFC] GnuTLS: Support TOFU certificate checking.

[Lars Magne Ingebrigtsen <larsi@gnus.org>]

Toke Høiland-Jørgensen <toke@toke.dk> writes:

>> I like the simplicity of it. It would be nice to do this inside Emacs
>> itself (it's OK if it requires some kind of `emacs --batch' call,
>> doesn't have to be immediate). Either way, the errors should tell us
>> specifically what to run from the command line in these two cases:
>
> I have an updated version where I split out the parameters into
> :tofu-strict and :tofu-auto, where the latter will automatically add a
> certificate that hasn't been seen before (and fail on mismatch only).
> This might be more suitable to have turned out by default.

Well, I kinda think the TOFU stuff is a fine band-aid, but we really
need a suture here, and the band-aid really sounds like it would more
get in the way of getting what we really need.  :-)

Anything less than what I described earlier in this thread doesn't
really give the Emacs users the security they need.  For instance, it
doesn't help with the man-in-the-middle-stripping-the-STARTTLS-announcement.

To make this workable (i.e., if we add lots of manual management, users
won't bother), we need a more complete solution.

I don't really see the TOFU thing in itself (which would arise naturally
as a side-effect from the Emacs-driven certificate handling we need) as
a step forward, I'm sorry to say.

But it all depends on how realistic the `open-network-stream' scenario I
proposed is -- I don't know the details of how the gnutls library works,
and whether it would allow us the proposed work flow.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no