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Re: [TLS] Non-extension solutions (requirements)

David-Sarah Hopwood <david-sarah@jacaranda.org> Mon, 16 November 2009 03:16 UTC

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Date: Mon, 16 Nov 2009 03:16:02 +0000
From: David-Sarah Hopwood <david-sarah@jacaranda.org>
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Subject: Re: [TLS] Non-extension solutions (requirements)
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Michael D'Errico wrote:
> With the RI extension, a client that wants to protect itself from an
> unpatched server needs to abort the handshake before sending its
> Finished message.  This is the key -- neither side will know for
> certain that an attack took place since Finished messages are not
> exchanged, and can't be if you want to remove the possibility of an
> attack.

I don't see why that is a problem. Being able to prove that an attack
took place (or to distinguish an attack from, say, line noise or any
of many possible implementation errors) was not a design goal of TLS,
and the protocol doesn't achieve that for numerous reasons. It is
hard to see how a secure channel protocol could possibly achieve this
goal, for active attacks.

-- 
David-Sarah Hopwood  ⚥  http://davidsarah.livejournal.com

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