Re: [TLS] A la carte handshake negotiation

Nico Williams <nico@cryptonector.com> Sun, 28 June 2015 05:09 UTC

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Date: Sun, 28 Jun 2015 00:09:46 -0500
From: Nico Williams <nico@cryptonector.com>
To: Dave Garrett <davemgarrett@gmail.com>
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Subject: Re: [TLS] A la carte handshake negotiation
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On Fri, Jun 26, 2015 at 09:51:47PM -0400, Dave Garrett wrote:
> On Friday, June 26, 2015 09:40:35 pm Nico Williams wrote:
> > We could do even better: stop cartesian products altogether.
> > 
> >   TLS_SRV_AUTH_NONE (anon)
> >   TLS_SRV_AUTH_PKIX (certs)
> >   TLS_SRV_AUTH_PSK  (also authenticates the client)
> 
> What's "SRV" in this context, short for "server"?

Yes.

> > [...]
> 
> I don't really like this variation. It adds a lot more stuff in the
> existing cipher suite codespace and makes it a lot more complicated.

It would reduce the number of new cipher suite allocations.

> I'd rather either go for less change or maximal change, i.e. current
> draft proposal or deprecate suites in favor of a new extension. I

I didn't necessarily mean that these are all in one namespace.  I was
ambiguous on purpose.  I'd be ecstatic with any solution that gets us
past the cartesian product registry and pessimized negotiation.

> don't think this sort of middle-ground is worth it. I suggested
> something somewhat similar to this in prior discussion, but we ended
> up moving towards the current proposal.

Fully dropping the pre-1.3 pre-registered cartesian products and having
N sets of negotiable things instead *is* the maximal change.  Whether we
use a new extension (sure, that seems cleanest) or not is a detail.

Nico
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