Re: [TLS] Version negotiation, take two

Hubert Kario <hkario@redhat.com> Wed, 14 September 2016 16:39 UTC

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From: Hubert Kario <hkario@redhat.com>
To: David Benjamin <davidben@chromium.org>
Date: Wed, 14 Sep 2016 18:39:43 +0200
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Subject: Re: [TLS] Version negotiation, take two
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On Wednesday, 14 September 2016 16:17:50 CEST David Benjamin wrote:
> Yes, we find list intolerance too---servers which only look at the second
> byte in a cipher suite, servers which forgot a default in their NamedGroup
> switch-case, servers which get confused on unknown HashAlgorithms, servers
> which require the final extension non-empty---but this is dramatically less
> than version intolerance. It's usually within tolerable levels that we
> needn't resort to fallbacks.
> 
> The proposal switches from something which we know does not work to
> something new. Perhaps this new one will break too, but it is very similar
> to things that have worked before, and I am hopeful that GREASE will help.

Was the option to do "one extension point = specific TLS version supported" 
discussed too? What arguments are there against it?

-- 
Regards,
Hubert Kario
Senior Quality Engineer, QE BaseOS Security team
Web: www.cz.redhat.com
Red Hat Czech s.r.o., Purky┼łova 99/71, 612 45, Brno, Czech Republic