Re: [TLS] draft-ietf-tls-cached-info-02 / New "Fast-Track" draft posted

"Brian Smith" <brian@briansmith.org> Tue, 02 February 2010 15:16 UTC

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From: "Brian Smith" <brian@briansmith.org>
To: "'Simon Josefsson'" <simon@josefsson.org>
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Date: Tue, 2 Feb 2010 09:16:23 -0600
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Cc: tls@ietf.org
Subject: Re: [TLS] draft-ietf-tls-cached-info-02 / New "Fast-Track" draft posted
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Simon Josefsson wrote:
> "Brian Smith" <brian@briansmith.org>; writes:
> 
> > I am very interested in the ideas that motivate the cached info
> > extension.
> 
> Stefan can speak for his reasons, but I see significant advantage in
> being able to cache the list of trusted CA certs that is sent from
> server to client.  For whatever reasons (which likely include poor
> server configuration), I've seen TLS handshakes in the wild that are as
> large as 30-40kb which cause some operational pains.

I didn't phrase this clearly. What I meant to say is "I find the cached info
extension interesting because optimizing the handshake is very important to
me."

> The server certificate _chain_ (note that it is the entire chain that
> is cached, not just the server certificate) also has potential of being
> large (and growing over time, it seems, as more and more interesting
> X.509 extensions are added).

Agreed. My suggestion is really just trying to extend the usefulness of this
extension to the case where the certificate chain is not large.

Cheers,
Brian