Carl wrote:
> If this mechanism only applies to certs that conform to a profile that 
> requires presence of key identifier in the AKID extension, state that up 
> front.

I think this is a reasonable request.

Aaron wrote:
> RFC 5280 requires both that the AKID extension be present and that the 
> keyIdentifier field be present within it

I think it's worth pointing this out too.

> Do other members of this list think that using some form of the Issuer Name 
> bytes would be better than using the keyIdentifier?

Only if "some form of the Issuer Name bytes" turns out to be the CertID 
structure used by OCSP and earlier ARI drafts!  Reusing an appropriate existing 
mechanism can have benefits, but if we're now talking about defining a new 
mechanism then I'll point out that Name matching can be a bit of a footgun...

From https://datatracker.ietf.org/doc/html/rfc5280#section-8:
   Inconsistent application of name comparison rules can result in
   acceptance of invalid X.509 certification paths or rejection of valid
   ones.  The X.500 series of specifications defines rules for comparing
   distinguished names that require comparison of strings without regard
   to case, character set, multi-character white space substring, or
   leading and trailing white space.  This specification relaxes these
   requirements, requiring support for binary comparison at a minimum.

   CAs MUST encode the distinguished name in the subject field of a CA
   certificate identically to the distinguished name in the issuer field
   in certificates issued by that CA.  If CAs use different encodings,
   implementations might fail to recognize name chains for paths that
   include this certificate.  As a consequence, valid paths could be
   rejected.

________________________________
From: Acme <[email protected]> on behalf of Aaron Gable 
<[email protected]>
Sent: 27 February 2024 05:23
To: Carl Wallace <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: [Acme] I-D Action: draft-ietf-acme-ari-03.txt

CAUTION: This email originated from outside of the organization. Do not click 
links or open attachments unless you recognize the sender and know the content 
is safe.

On Mon, Feb 26, 2024 at 4:36 AM Carl Wallace 
<[email protected]<mailto:[email protected]>> wrote:
Two comments on the third paragraph of section 4.1:

- The addition of section identifiers for the references makes the sentences 
harder to read. Maybe wrapping the section identifiers and reference in 
parentheses.

Thanks, this feedback is appreciated. I've gone back and forth a lot on how 
best to do these references, and tried a bunch of different things, and this 
was my favorite phrasing so far. Unfortunately putting them in parentheses 
causes the resulting sentence to not read in plain English, unless I'm 
misunderstanding your suggestion?

- The preparation of the URI uses the keyIdentifier field of 
AuthorityKeyIdentifier. That field is optional. What should occur if it is 
absent (or if AKID is absent)? Given 5280 requires uniqueness for issuer name 
and serial and the issuer field is not optional, would the issuer field make 
for a better target than AKID? If this mechanism only applies to certs that 
conform to a profile that requires presence of key identifier in the AKID 
extension, state that up front.

This is a very interesting point. RFC 5280 requires both that the AKID 
extension be present and that the keyIdentifier field be present within it 
(Section 
4.2.1.1<https://datatracker.ietf.org/doc/html/rfc5280#section-4.2.1.1>: "The 
keyIdentifier field of the authorityKeyIdentifier extension MUST be included in 
all certificates generated by conforming CAs to facilitate certification path 
construction."). So it's not obvious to me that the issuer name + serial 
uniqueness is any more required than the existence of the keyIdentifier field. 
Do other members of this list think that using some form of the Issuer Name 
bytes would be better than using the keyIdentifier?

Thanks again,
Aaron
_______________________________________________
Acme mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/acme

Reply via email to