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Re: [TLS] Addressing cookie theft (think BEAST) with channel bound cookies using TLS session IDs

Florian Weimer <fweimer@bfk.de> Thu, 29 September 2011 10:49 UTC

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From: Florian Weimer <fweimer@bfk.de>
To: Nico Williams <nico@cryptonector.com>
References: <CAK3OfOjKwn16uKN44AjDDYoFxJwdghK=21zEKr6zSrp4gzATFQ@mail.gmail.com>
Date: Thu, 29 Sep 2011 10:52:08 +0000
In-Reply-To: <CAK3OfOjKwn16uKN44AjDDYoFxJwdghK=21zEKr6zSrp4gzATFQ@mail.gmail.com> (Nico Williams's message of "Wed, 28 Sep 2011 15:10:11 -0500")
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Cc: tls@ietf.org
Subject: Re: [TLS] Addressing cookie theft (think BEAST) with channel bound cookies using TLS session IDs
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* Nico Williams:

> A while back Dirk Balfanz proposed something he called "origin bound
> certificates" and "channel bound cookies".  A lighter-weight
> alternative (i.e., involving no protocol changes) would be nice.
> Mine: use TLS session IDs as the channel binding.

If we're interested in working around the cookie issue (as opposed to
fixing the protocol issue), I think it would be simpler to include a
random prefix in the cookie, ignored by the server, and the server would
change the prefix every few requests.

-- 
Florian Weimer                <fweimer@bfk.de>
BFK edv-consulting GmbH       http://www.bfk.de/
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99

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