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Re: [TLS] TLS 1.3 multiple PSKs (was session tickets) from the client?

Viktor Dukhovni <ietf-dane@dukhovni.org> Thu, 10 May 2018 23:08 UTC

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From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Date: Thu, 10 May 2018 19:08:11 -0400
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Subject: Re: [TLS] TLS 1.3 multiple PSKs (was session tickets) from the client?
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> On May 10, 2018, at 1:28 PM, Viktor Dukhovni <ietf-dane@dukhovni.org> wrote:
> 
> On a related note, should a client sending both a resumption and
> an external PSK place the resumption PSK first in the list of
> PSK identities?  My concern is that server implementations might
> otherwise recognize the external PSK first, and then not even
> look at the resumption PSK.  Is that a valid concern?
> 
> Should server implementations first see if any of the PSKs
> are resumption PSKs before considering the rest?

Perhaps a better question is:

 Should servers issue resumption tickets after an initial PSK handshake?
 And if so, should resumption be preferred for any reason when the client
 sends both a resumption ticket and the external PSK?

-- 
	Viktor.

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