Re: [TLS] One approach to rollback protection

Badra <badra@isima.fr> Tue, 27 September 2011 15:37 UTC

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Date: Tue, 27 Sep 2011 17:40:20 +0200
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From: Badra <badra@isima.fr>
To: Eric Rescorla <ekr@rtfm.com>
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Subject: Re: [TLS] One approach to rollback protection
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Hi,

do the current TLS servers parse all the cipher suites received in the
ClientHello?

Best regards
Badra

On Tue, Sep 27, 2011 at 1:44 AM, Eric Rescorla <ekr@rtfm.com>; wrote:

> I've been doing some thinking about how to prevent rollback to
> TLS 1.0/SSLv3 from TLS 1.1-capable agents.
>
> Since there's very little deployment of TLS 1.1+, basically anything
> we do now will roll out more or less in parallel with TLS 1.1 deployment,
> as long as it's backward compatible.The obvious technique here is to
> stuff the relevant indicator in the cipher suites list, since we know that
> servers ignore unknown entries there.
>
> I've taken an initial crack at a draft for this:
>
> http://svn.resiprocate.org/rep/ietf-drafts/ekr/draft-rescorla-tls-version-cs.txt
>
> -Ekr
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