Re: [TLS] Salsa20 and Poly1305 in TLS

Adam Langley <agl@google.com> Tue, 30 July 2013 22:09 UTC

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From: Adam Langley <agl@google.com>
Date: Tue, 30 Jul 2013 18:08:57 -0400
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To: Geoffrey Keating <geoffk@geoffk.org>
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Subject: Re: [TLS] Salsa20 and Poly1305 in TLS
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On Tue, Jul 30, 2013 at 2:26 PM, Geoffrey Keating <geoffk@geoffk.org> wrote:
> Surely if you discover that the remote end appears to support only SSL
> 3 but yet somehow supports Salsa, you should stop trying to
> communicate because you're under a downgrade attack?

Unfortunately there exist middleboxes that prevent > SSLv3 from being
used, but which don't interfere with the encrypted traffic itself.
Breaking these is costly, and fundamentally ineffective because the
users will switch to a client that `works'. Ideally we would be able
to support secure connections in the broadest range of situations.


Cheers

AGL