Re: [Ace] [core] Proposed charter for ACE (EAP over CoAP?)

Benjamin Kaduk <kaduk@mit.edu> Tue, 12 January 2021 19:05 UTC

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Date: Tue, 12 Jan 2021 11:05:16 -0800
From: Benjamin Kaduk <kaduk@mit.edu>
To: Dan Garcia Carrillo <garciadan@uniovi.es>
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Subject: Re: [Ace] [core] Proposed charter for ACE (EAP over CoAP?)
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Hi Dan,

Sorry to reply to such an old message...

On Sat, Dec 12, 2020 at 06:36:53PM +0100, Dan Garcia Carrillo wrote:
> Hi Mališa,
> 
> 
> El 11/12/2020 a las 19:45, Mališa Vučinić escribió:
> >
> > Hi Dan,
> >
> > Thanks for the clarification regarding minimal-security. The points 
> > that you mention below, e.g. flexible authentication or the fresh 
> > generation of the PSK, were never in the design scope of our work.
> >
> > While I fail to understand what exactly do you plan on using 
> > EAP-over-CoAP for, I do not object on this work being done in ACE if 
> > you are willing to spend cycles on it. I do have reservations on the 
> > lightweight aspect of this, however, considering that the sequence 
> > diagram that you depict in Fig. 2 in draft-marin-ace-wg-coap-eap-06 
> > spans 3 pages and consumes 2 round trips just to get things started! 
> > Surely, we can do better?
> >
> Yes, we will submit an updated version of the draft.

When you do, I suggest putting in some discussion of the relative
size/overhead for CoAP as EAP lower-layer vs the EAP payloads themselves.
I note that the IESG recently approved draft-ietf-emu-eaptlscert that
discusses some pathological cases with TLS-based EAP methods and very large
certificate chains.  While I assume that you're not planning to do
EAP-over-CoAP with such long TLS certificate chains, giving reviewers a
sense for how big of an improvement this mechanism can be will presumably
be helpful.

Thanks,

Ben