Subject: [Acme] Francesca Palombini's Discuss on draft-ietf-acme-star-delegation-07: (with DISCUSS and COMMENT)

From: Francesca Palombini via Datatracker <[email-masked]>
Date: Wed, 07 Apr 2021 00:43:28 -0700

Francesca Palombini has entered the following ballot position for
draft-ietf-acme-star-delegation-07: Discuss

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DISCUSS:
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EDIT (06-04-2021): Thank you very much to Carsten Bormann for the CDDL review:
https://mailarchive.ietf.org/arch/msg/cbor/23A-PFhRY-pdkg2-Kgcd4jqySVo/ Authors
- please make sure to answer Carsten's comments (and keep me in cc so I can
clear my DISCUSS).

EDIT (07-04-2021): Also wanted to point out the IANA Designated Expert review
to make sure it is addressed (found in the datatracker, but which I report here
for simplicity as well) - thank you to Richard Barnes for it:

 1. The "delegation" field is currently attached to the "identifier" object,
 which is a bad semantic fit in a few ways. ACME orders can have multiple
 identifiers, and delegations can describe multiple SAN values, yet this design
 assumes singularity on both sides. This field should be moved to the order
 object; in fact, if you wanted to be more radical, you could even use it to
 replace the "identifiers" field in the newOrder request.

2. The "allow-certificate-get" field is listed as configurable. It seems like
this is a matter of CA policy, so it should either be non-configurable, or if
you allow the client to request a value for it, there should be a clear
specification that the server is allowed to ignore the client's preference.

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COMMENT:
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Thank you for the work on this document, which I found clear and easy to read.
You can find some minor comments below. The only one that might require more
attention is 7. about IANA expert guidelines missing.

EDIT TO ADD (06-04-2021): I see that Lars has added a discuss about the same
topic - I support that discuss.

Francesca

1. -----

   the ACME CA and waits for the explicit revocation based on CRL and
   OCSP to propagate to the relying parties.

   ...

   result, the TLS connection to the dCDN edge is done with an SNI equal

FP: Please expand CRL, OCSP and SNI on first use.

2. -----

   *  delegations (required, string): A URL from which a list of
      delegations configured for this account can be fetched via a POST-
      as-GET request.

FP: the second occurrence of "delegation" needs a pointer to the next
subsection - Delegation Objects, otherwise this definition becomes confusing
(delegations is a URL from which a list of delegations can be fetched).

3. -----

   An example delegation object is shown in Figure 3.

FP: please note that the examples are in JSON.

4. -----

   (Forbidden) and type "urn:ietf:params:acme:error:unknownDelegation".

FP: suggestion to change to:

   (Forbidden), providing a problem document [RFC7807] with type 
   "urn:ietf:params:acme:error:unknownDelegation", as registered in section 5.5.

The error type appears later on as well (e.g. section 2.3.2), but even without
repeating each time, I think this reference at least here where it appears
first would help the reader.

5. -----

   The Order object created by the IdO:

   ...

   *  MUST copy the "star-certificate" field from the STAR Order.  The

FP: (suggestion for clarification) because there are 2 Orders going on in
sequence, this bullet point and more precisely "from the STAR Order" is
slightly confusing. You could use Order1 and Order2 as you have used in Figure
1 to clarify things (I believe this should be "from the STAR Order2 into
Order1) (Note that this is just a suggestion, the rest of the text is mostly
clear about which Order it refers to) Otherwise, I think it would be good to
add "... from the STAR Order into its Order resource." The same comment apply
to the next occurrence:

   *  MUST copy the "certificate" field from the Order, as well as

6. -----

   uCDN is configured to delegate to dCDN, and CP is configured to
   delegate to uCDN, both as defined in Section 2.3.1.

FP: Re Figure 12: I assume that 0. refers to the configuration CP and uCDN
share? In this case, why is there no arrow between uCDN and dCDN? If my
assumption is wrong, then what's the meaning of 0?

7. -----

FP: This document defines two new registry, one with policy Specification
required and the other Expert review (both of which will need designated
experts). https://tools.ietf.org/html/rfc8126#section-5.3 states that:

   When a designated expert is used, the documentation should give clear
   guidance to the designated expert, laying out criteria for performing
   an evaluation and reasons for rejecting a request.  In the case where

I have noticed that RFC 8555 only provided guidance for one of its registries,
and that the registries are quite straight forwards, but I still believe that
having some guidance for the experts to evaluate requests helps.