Hi Martin, Thanks for your review.
On 19/06/2017, 23:34, "Acme on behalf of Martin Thomson" <[email protected] on behalf of [email protected]> wrote: > > A few brief comments on this draft. > > On 16 June 2017 at 22:19, <[email protected]> wrote: > This memo proposes an ACME extension to enable the issuance of short- > term and automatically renewed certificates. This allows a domain > name owner to delegate the use of certificates to another party, > while retaining the capability to cancel this delegation at any time > with no need to rely on certificate revocation mechanisms. > > I found the introduction overly specific. The generic use case is to > simplify the deployment of certificates to unprivileged nodes. The > unprivileged nodes then only need to be configured with a URL for > their certificates. > > That requires a couple of paragraphs of exposition at most. This > extends to Section 2, which describes a system architecture that > implies the existence of protocol elements that are simply not defined > in this document. > > Sections 1 and 2 could much more clearly describe what *this* document > provides. It provides an extension to ACME that allows for the > creation of a certificate that automatically renews. > > The focus on the CDN case affects the entire document. The point is > that the authorized entity is delegating the ability to use a > certificate for its name to an unprivileged node. Don't use "CDN", > "content owner" or any of these highly specific terms. Use generic > terms; make new terms if necessary. FWIW, while NDC is a cute > reversal, "consumer" really isn't accurate. Agree, there is still a bit of LURK baggage attached (especially here, but also in a few other points). We will do an editorial pass to streamline the document before -01 and take in the suggestions above. > draft-iab-web-pki-problems has been abandoned. It's not a great idea > to cite it. OK, will drop the reference -- too bad, though. > In Section 3.1.1, I think that the resolution of these fields, being > in days, is not conducive to reducing granularity. (Or will you > permit 5.7e-3 as a value?) Seconds granularity then? 32 bit should be enough for >100 years while allowing baryon-like lifetimes on the other end of the scale :-) (Personally, I'd avoid any string representation, but that's my taste.) > Section 3.1.1 needs to clearly articulate how > "recurrent-certificate-validity" (could this be any more verbose and > hard to type?) relates to "expires". OK > Please include a definition for the new attributes, rather than just > providing an example and commenting the JSON. OK > In Section 3.1.2, you REALLY, REALLY need to authenticate this > request. Sure. Every non-RO operation needs to be authenticated. We forgot to be explicit about that; thanks for spotting it. > My suggestion is to change this to a POST request with { > "recurrent": false }. (I'd have suggested PUT or PATCH, but ACME's > reliance on JWS perverts that in ways that is incompatible with those > methods.) I have no strong opinion about the syntax of the order termination. DELETE just seemed the most natural to me (certainly more straightforward than POSTing '{ "recurrent": false }'), but I'm probably missing something? > In Section 3.2, the discussion about a Proxy is misleading. The only > relevant actor in this is an ACME client. This section could be > reduced to: > > An ACME client discovers whether a server supports this extension by > examining a newly created order. The "recurrent" member will exist if > the server supports automatic recurring certificate issuance; the > "recurrent" member will be true if the server accepts the request. Yes, agreed. This is another example of the LURK clean-out that we need to finish off. > Can the server specify a shorter value for "recurrent-total-lifetime"? Yes. And if the client is not happy with the chosen value I guess it will just abandon the order and let it expire (as suggested in 3.2). > I don't understand Section 3.3 at all. I'd recommend removing this > section. The DNO will decide what authorizations it requests amply > without this level of proscription in standards. Yaron: thoughts on this? > In Section 3.4, the use of the Expires header field is a common > mistake. This is an HTTP caching directive. It should probably be > shorter than the expiration time of the certificate (half in fact), > but not for the reasons that you might think. The purpose of a > recommendation on Expires is to ensure that the certificate is not > cached beyond the point where a newer certificate will be issued. You > should remove this text. OK > Section 5.1 should be promoted to Section 5 OK > Don't mention time-sensitive policy actions by the CA/B Forum. Makes sense. > Can't you simply ensure that the CDN can't modify the CAA record? This is the minimum we could say. At this point, I think we are trying to explore a bit what other mitigations can be put in place. > One further thought. ACME uses an absolute time for expiration. This > uses a relative time. I think that I prefer the former. I realize that > consistency might be impossible in this case, since the recurrent > duration is necessarily relative, but I though it worth raising. This is a good observation. Maybe instead of mirroring "recurrent-total-lifetime", server could come back with the absolute time when the renewal ends on its side (e.g., "recurrent-expiration"). Cheers, thanks _______________________________________________ Acme mailing list [email protected] https://www.ietf.org/mailman/listinfo/acme
