Re: [TLS] draft-jay-tls-psk-identity-extension-01

Eric Rescorla <ekr@rtfm.com> Wed, 21 September 2016 20:50 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Wed, 21 Sep 2016 13:49:24 -0700
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To: David Woodhouse <dwmw2@infradead.org>
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Cc: "jayaraghavendran@gmail.com" <jayaraghavendran@gmail.com>, "tls@ietf.org" <tls@ietf.org>, Nikos Mavrogiannopoulos <n.mavrogiannopoulos@gmail.com>
Subject: Re: [TLS] draft-jay-tls-psk-identity-extension-01
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On Wed, Sep 21, 2016 at 1:43 PM, David Woodhouse <dwmw2@infradead.org>;
wrote:

> On Wed, 2016-09-21 at 13:36 -0700, Eric Rescorla wrote:
> > >
> > I don't see how this is appreciably easier than just having the
> > client offer one and then the server HRR.
>
> If I have ten PSK identities I can offer, it may take nine round-trips
> before I send the one you want.
>
> If I list them all in my first ClientHello and you *tell* me which one
> you want, that's only one more round-trip.


Is there a real-world use-case where this is relevant?

-Ekr