Re: [TLS] A la carte handshake negotiation

Nico Williams <nico@cryptonector.com> Mon, 29 June 2015 12:55 UTC

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Date: Mon, 29 Jun 2015 07:55:40 -0500
From: Nico Williams <nico@cryptonector.com>
To: Peter Gutmann <pgut001@cs.auckland.ac.nz>
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Subject: Re: [TLS] A la carte handshake negotiation
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On Mon, Jun 29, 2015 at 08:58:11AM +0000, Peter Gutmann wrote:
> Nico Williams <nico@cryptonector.com>; writes:
> >On Sun, Jun 28, 2015 at 10:44:03AM +0300, Ilari Liusvaara wrote:
> >
> >>"Chinese menus" with coupled choices are classical source of interop
> >>problems.
> >
> >It's worked for SSHv2.
> 
> It worked for SSH because implementations use algorithm groups in
> highly stereotyped ways, so you have a de facto interop profile. Try
> negotiating e.g. RC4+SHA in one direction and AES+SHA2 in the other
> and see how quickly the wheels fall off.

That was an idiotic mistake that nobody takes advantage of.