Re: [TLS] Last Call: draft-hoffman-tls-additional-random-ext

Martin Rex <mrex@sap.com> Wed, 21 April 2010 22:56 UTC

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From: Martin Rex <mrex@sap.com>
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To: paul.hoffman@vpnc.org (Paul Hoffman)
Date: Thu, 22 Apr 2010 00:55:18 +0200 (MEST)
In-Reply-To: <p06240887c7f52b14f905@[10.20.30.158]> from "Paul Hoffman" at Apr 21, 10 03:29:06 pm
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Cc: ietf@ietf.org, tls@ietf.org
Subject: Re: [TLS] Last Call: draft-hoffman-tls-additional-random-ext
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Paul Hoffman wrote:
> 
> At 12:05 AM +0200 4/22/10, Martin Rex wrote:
> >The IESG wrote:
> >>
> >> The IESG has received a request from an individual submitter to consider
> >> the following document:
> >>
> >> - 'Additional Random Extension to TLS '
> >>    <draft-hoffman-tls-additional-random-ext-01.txt> as a Proposed Standard
> >
> >
> >I'm somewhat confused to see a Last Call for this proposal.
> >
> >We had a discussion on this document on the TLS WG mailing list and
> >determined that this proposal is completely unable to achieve
> >the stated goal.  This extension is completely bogus.
> 
> You came to that conclusion; many other folks disagreed. You stated
> that you thought it was not useful in some environments, namely with
> RSA authentication where the client has a broken PRNG. If that is the
> only environment you care about, then this extension is not useful.
> TLS is used in many other environments, of course.

Well, I'm sorry.

There was not a single technical argument against the determination
that this extension is completely bogus in the discussion.


It is simply impossible to make up for the lack of entropy
(= secret randomness) with the addition of any amount of
published randomness, such as this extension suggests.


Get a cryptographer to make a convincing case for the value of
this extension in TLS, otherwise this extension should *NOT* be
standardized by the IETF.


-Martin