Subject: [Ace] Options for Transporting Access Tokens

From: Hannes Tschofenig <[email-masked]>
Date: Wed, 2 Mar 2016 18:42:16 +0100

Hi all,

in the ACE architecture there needs to be the option to pass the access
token from the client to the resource server. It turns out that there
are various options to do so (each with pros & cons).

Here is the list we discussed at the interim meeting:
= POST to a well-known or discoverable resource (e.g. /authz-info)
= Use a dedicated CoAP option
= Use TLS supplemental data (RFC 4680)
= Use psk_identity (DCAF)
= Define new TLS certificate type (similar to RPK)
= Use ticket extension (RFC 5077)

Here are the slides from the ACE virtual interim meeting providing
further background information:
https://www.ietf.org/proceedings/interim/2016/03/02/ace/slides/slides-interim-2016-ace-1-2.pdf

Since we are still in the phase of exploring options and finding new
options we soliciting your input without setting a specific deadline.

Ciao
Hannes & Kepeng