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Re: [TLS] Unifying tickets and sessions

Viktor Dukhovni <ietf-dane@dukhovni.org> Thu, 23 October 2014 22:58 UTC

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Date: Thu, 23 Oct 2014 22:58:20 +0000
From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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References: <CAK3OfOj9bZcSDdWhHGeGT0STg6XBkYaExW+rQFN-FFE4oaPLrw@mail.gmail.com> <54483C33.4000702@polarssl.org> <11886639.VyNDkQ3oKj@pintsize.usersys.redhat.com> <54493904.7010807@fussenegger.info> <20141023174537.GW19158@mournblade.imrryr.org> <5449463D.7080904@fussenegger.info> <20141023183637.GX19158@mournblade.imrryr.org> <03546F3D-816C-481A-A577-9797855A9DED@pahtak.org> <20141023200134.GY19158@mournblade.imrryr.org> <5449837C.7080305@fussenegger.info>
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Subject: Re: [TLS] Unifying tickets and sessions
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On Fri, Oct 24, 2014 at 12:38:52AM +0200, Richard Fussenegger wrote:

> With N = 2 your tickets are either T or 2 * T, depending on the time the
> client received the ticket. The client sends the ticket to the server
> expecting to continue were it left of but instead ends up with a full new
> handshake because the ticket is rejected, although the lifetime indicates
> that it's valid. (Of course no big deal.)

This is not true, I only promise the client a lifetime of T, so
the client asks for a new session after T anyway.  And the time
the ticket is good for is not discrete, it varies uniformly between
T and 2*T.

> With N = 3 your ticket is always 2 * T, no matter when the client received
> the ticket.

Not true, it varies uniformly between 2*T and 3*T.  The client
lifetime hint should be 2*T in this case.

-- 
	Viktor.

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