Re: [TLS] 0-RTT and Anti-Replay

Viktor Dukhovni <ietf-dane@dukhovni.org> Mon, 23 March 2015 16:59 UTC

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Date: Mon, 23 Mar 2015 16:59:36 +0000
From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Subject: Re: [TLS] 0-RTT and Anti-Replay
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On Mon, Mar 23, 2015 at 06:52:01PM +0200, Ilari Liusvaara wrote:

> On Mon, Mar 23, 2015 at 04:22:00PM +0000, Viktor Dukhovni wrote:
> > 
> >     * If clients make 0-RTT requests to a stack that does not
> >     support these, all connection abort when the stack requests
> >     non-expedited data, while expedited data is pending.
> 
> I regard that as very bad idea. The server should reject the
> 0-RTT data, not abort the connection, because the former can
> sanely be handled by the client, the latter can't.

A connection on which the initial data was lost is broken.  Signalling
such loss is simplest by dropping the connection.

In practice 0-RTT clients will talk to 0-RTT enabled servers.
Everyone else avoids the can of worms.  The 0-RTT mechanism will
support the specialized applications that need it.

--
	Viktor.