Subject: [Ace] Francesca Palombini's Yes on draft-ietf-ace-dtls-authorize-16: (with COMMENT)

From: Francesca Palombini via Datatracker <[email-masked]>
Date: Wed, 24 Mar 2021 08:49:41 -0700

Francesca Palombini has entered the following ballot position for
draft-ietf-ace-dtls-authorize-16: Yes

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COMMENT:
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Thank you for this document. Some minor comments below.

Francesca

1. -----

   The response MAY contain a "profile" parameter with the value

   authorizes the client, it returns an AS-to-Client response.  If the
   profile parameter is present, it is set to "coap_dtls".  The

         profile    : coap_dtls,

FP: s/profile/ace_profile

2. -----

   [RFC8747].  A resource server MUST have the capacity to store one
   access token for every proof-of-possession key of every authorized
   client.

FP: I am not sure this BCP 14 MUST is correct here.

3. ------

   raw public keys, it needs to determine which key to use.  The
   authorization server can help with this decision by including a "cnf"
   parameter in the access token that is associated with this
   communication.  In this case, the resource server MUST use the

FP: The example in Figure 4 show how the whole RPK of the client can be
included in the access_token, so maybe this paragraph should cover that case,
or the example changed.

4. -----

   token carries a symmetric key, the access token MUST be encrypted
   using a "COSE_Encrypt0" structure.  The authorization server MUST use

FP: Since only CWT is allowed in this profile, it might be good to reference
section 7.1 of RFC 8392.

5. -----

   the "psk_identity" field.  If key derivation is used, the resource
   server uses the "COSE_KDF_Context" information as described above.

FP: "COSE_KDF_Context" appears here for the first time, so this might need to
be rephrased.

6. -----

   As recommended in Section 5.8 of [I-D.ietf-ace-oauth-authz], this
   specification uses CBOR web tokens to convey claims within an access
   token issued by the server.  While other formats could be used as

FP: I think this warrants for RFC 8392 to be moved to normative reference (but
can be convinced of the contrary).