Re: [Ace] [Anima] est-coaps clarification on /att and /crts

Michael Richardson <mcr+ietf@sandelman.ca> Wed, 12 December 2018 21:50 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Hannes Tschofenig <Hannes.Tschofenig@arm.com>
cc: "Panos Kampanakis \(pkampana\)" <pkampana@cisco.com>, "ace\@ietf.org" <ace@ietf.org>, "anima\@ietf.org" <anima@ietf.org>, Peter van der Stok <stokcons@bbhmail.nl>, "Max Pritikin \(pritikin\)" <pritikin@cisco.com>
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Date: Wed, 12 Dec 2018 16:49:59 -0500
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Subject: Re: [Ace] [Anima] est-coaps clarification on /att and /crts
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Hannes Tschofenig <Hannes.Tschofenig@arm.com> wrote:
> > We want all our clients to be authenticated by DTLS before they start
> > loading up our RF network.
> > I'm not suggesting that the DTLS be skipped, I'm suggesting that the
> > client certificate presented might be meaningless to the EST server.

> I am curious what security model you have in mind? If you don't do client
> authentication then you are essentially issuing certificates to an
> anonymous entity. This feels like a very bad idea, particularly since the
> CA is supposed to assert the identifier of the client via the certificate.

Clients which are not **yet** authenticatable.
The client shows up, does a DTLS connection.

We let the DTLS connection succeed, because we want to record the particulars
of the client, so we can ask a human.  Much like happens when you ssh to
a new host: it stops to ask if you you agree with the key.
You don't know, so you hit ^C.
So, that's all.  We don't intend to issue certificates... yet.

I'm also asking if there is some use case where the client might legitimate
need the list of trust anchors (/cacerts request) in order so that it can...?
(I couldn't think of a use case)

--
Michael Richardson <mcr+IETF@sandelman.ca>ca>, Sandelman Software Works
 -= IPv6 IoT consulting =-