Re: [TLS] Broken browser behaviour with SCADA TLS

Ilari Liusvaara <ilariliusvaara@welho.com> Wed, 04 July 2018 08:16 UTC

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Date: Wed, 4 Jul 2018 11:15:19 +0300
From: Ilari Liusvaara <ilariliusvaara@welho.com>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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Subject: Re: [TLS] Broken browser behaviour with SCADA TLS
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On Wed, Jul 04, 2018 at 07:57:41AM +0000, Peter Gutmann wrote:
> Ilari Liusvaara <ilariliusvaara@welho.com>; writes:
> 
> >More serious problem is servers returning too small modulus due lack of
> >negotiation. Which was the reason why Chrome disabled DHE.
> 
> Why not reject the handshake if the modulus is too small, rather than
> disabling all DHE suites on the off chance that the server returns a value you
> don't like?

Chrome initially did that. It caused quite a lot of bad feedback from
owners of various bad embedded stuff. The thread on relevant forums was
quite something. Hundreds of messages blaming Google for breaking
stuff.


-Ilari