Re: [TLS] New Cached info draft

Martin Rex <mrex@sap.com> Wed, 31 March 2010 19:08 UTC

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From: Martin Rex <mrex@sap.com>
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To: agl@imperialviolet.org (Adam Langley)
Date: Wed, 31 Mar 2010 21:08:49 +0200 (MEST)
In-Reply-To: <o2g396556a21003311032wac904836h89b84f1a1fdeb94b@mail.gmail.com> from "Adam Langley" at Mar 31, 10 01:32:33 pm
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Cc: tls@ietf.org
Subject: Re: [TLS] New Cached info draft
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Adam Langley wrote:
> 
> On Tue, Mar 30, 2010 at 8:32 PM, Stefan Santesson <stefan@aaa-sec.com>; wrote:
> > This and the fact that it mixes the use of two extensions makes me feel a
> > bit uncomfortable with this.
> >
> > Is there a compelling use case?
> 
> I agree that the mixing of extensions here is a little nasty. Maybe
> this is best left to the multi ocsp draft.

Although it looked like a pretty good candidate for caching,
I'm starting to believe the multi OCSP extension should take care of
this optimization.  The ClientHelloExtension container of that
extension should provide room for (at least) two pieces of
information:  A limit/constraint for "producedAt" and a hash of
either the server certificate or whole server certificate chain
which the client expects to receive from the server and for which
the client still has OCSP responses cached that it considers
acceptably fresh.


-Martin