Re: [TLS] Inclusion of OCB mode in TLS 1.3

Nikos Mavrogiannopoulos <nmav@redhat.com> Mon, 19 January 2015 09:03 UTC

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From: Nikos Mavrogiannopoulos <nmav@redhat.com>
To: Aaron Zauner <azet@azet.org>
Date: Mon, 19 Jan 2015 10:03:09 +0100
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Cc: Manuel Pégourié-Gonnard <mpg@polarssl.org>, TLS Mailing List <tls@ietf.org>
Subject: Re: [TLS] Inclusion of OCB mode in TLS 1.3
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On Sat, 2015-01-17 at 16:11 +0100, Aaron Zauner wrote:
> > > (EC)DHE:
> > > TLS_DHE_RSA_WITH_AES_128_OCB	
> > > TLS_DHE_RSA_WITH_AES_256_OCB
> > > TLS_ECDHE_RSA_WITH_AES_128_OCB
> > > TLS_ECDHE_RSA_WITH_AES_256_OCB
> > > TLS_ECDHE_ECDSA_WITH_AES_128_OCB
> > > TLS_ECDHE_ECDSA_WITH_AES_256_OCB
> > > 
> > > PSK:
> > > TLS_DHE_PSK_WITH_AES_128_OCB
> > > TLS_DHE_PSK_WITH_AES_256_OCB	
> > > TLS_ECDHE_PSK_WITH_AES_128_OCB
> > > TLS_ECDHE_PSK_WITH_AES_256_OCB
> > > 
> > I think it would make sense to also include pure PSK (no DH) suite for very
> > constrained devices that can't afford the asymetric crypto.
> 
> Makes sense. So your suggestion is to swap or add these
> ciphersuites? I have no real-world data on the usage of TLS with
> pre-shared keys, nor it's deployment. I can only guess, would be
> interesting to hear the opinion of embedded development people on
> that subject.

I don't believe you can second guess here. There can be many valid
use-cases unknown to anyone in the WG, or IETF, as PSK is often used in
protocols which are non-standardized or standardized outside IETF.

regards,
Nikos