On Tuesday, April 5, 2022 4:43:49 AM EDT Alessandro Vesely wrote: > On Mon 04/Apr/2022 15:29:40 +0200 Scott Kitterman wrote: > > The diff is relative the last text I posted. > > Section 5 has to stay before Section 4. It makes no sense to exemplify > _dmarc.example.com if we haven't yet said that: > > Domain Owner and PSO DMARC preferences are stored as DNS TXT records > in subdomains named "_dmarc". > [Current Section 5.1] > > > Then, let's make a statement like so: > > Retrieving the DMARC record of a domain implies the following steps: > > 1. Prepend the label "_dmarc" to the domain name and issue a DNS Query > for a TXT record at the resulting domain. For example, if the domain is > example.com, query _dmarc.example.com. > > 2. Collate any string returned, in the order returned. > > 3. Records that do not start with a "v=" tag that identifies the > current version of DMARC are discarded. If multiple DMARC > records are returned, they are all discarded. > > > At this point, the algorithm can be expressed in a shorter form like so: > > 1. Set the current target to the identifier at hand, which is one of > the domain(s) described above. > > 2. Retrieve the DMARC record of the current target. > > 3. If the record exists and contains either psd=y or psd=n, stop. > > 4. Break the current target name into a set of "n" ordered > labels. Number these labels from right to left; e.g., for > "a.mail.example.com", "com" would be label 1, "example" would be > label 2, "mail.example.com" would be label 3, and so forth. > > 5. Count the number of labels in the current target. Let that number > be "x". If x = 1, stop. If x < 5, remove the left-most (highest- > numbered) label from the subject domain. If x >= 5, remove the > left-most (highest-numbered) labels from the subject domain until > 4 labels remain. The resulting DNS domain name is the new target > for subsequent lookups. > > 6. Go to 2. > > > Better?
Maybe. I'd say lets get a draft out that we agree gives the correct result before we start re-writing for taste. I don't think the order matters that much. An RFC is not a single pass compiler. Scott K _______________________________________________ dmarc mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmarc
