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

Ilari Liusvaara <ilari.liusvaara@elisanet.fi> Mon, 23 March 2015 17:07 UTC

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Date: Mon, 23 Mar 2015 19:07:33 +0200
From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
To: 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 04:59:36PM +0000, Viktor Dukhovni wrote:
> 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.

No, it isn't. The client will need to handle 0-RTT being lost
anyway.

And even if the client manages to guess what went wrong (if it doesn't
non-retry error is the best case), recovering from abort much more
expensive.


-Ilari