Subject: [Spasm] Erratum 4988

From: Jacob Hoffman-Andrews <[email-masked]>
Date: Wed, 5 Apr 2017 12:43:28 -0700

https://www.rfc-editor.org/errata_search.php?eid=4988

Rob Stradling said:
> 2. Bug?: Shouldn't this...
>   o  If A(X) is not null, and CAA(A(X)), then R(X) =
>      CAA(X), otherwise
>
> ...actually be this...
>
>   o  If A(X) is not null, and CAA(A(X)), then R(X) =
>      CAA(A(X)), otherwise

A further edit: "and CAA(A(X))" should be "and CAA(A(X)) is not empty"

Also, did you see my earlier suggestion on the list? I think now that we
aren't tree-climbing on CNAME targets, we can express this algorithm in
a more straightforward way that emphasizes its similarity to how other
DNS records are looked up:

----- Proposal -----
   Let CAA(X) be the record set returned by performing a CAA record
query on the domain name X, according to the name server lookup
algorithm specified in RFC 1034 section 4.3.2 (in particular including
CNAME responses). Let P(X) be the domain name produced by removing the
leftmost label of X.

 - If CAA(X) contains any CAA resource records, R(X) = CAA(X), otherwise
 - If P(X) is the root domain '.', then R(X) is empty, otherwise
 - R(X) = R(P(X))

----- End proposal -----