Re: [DNSOP] future-proofing (Re: Working Group Last Call for: Message Digest for DNS Zones)

["Wessels, Duane" <[e-mail]>]

> On Jan 8, 2020, at 3:55 PM, Michael StJohns <[e-mail]> wrote:


Mike,


Thank you for these suggestions.  The authors have discussed them.

> If the above is what you intended, then sections 3 and 4 should be labeled "Calculating/Verifying the DIGEST for the SIMPLE scheme", and there should be some description elsewhere indicating that later schemes will provide replacements for section 3 and 4 at a minimum.

This requires fairly large structural changes to the document. It isn't just relabeling the sections because some portions (duplicate RRs, RR ordering) are global, and some are scheme specific -- as it is a Working Group document, we'd like to see support from the WG to make them.

WG, please let us know by the end of the week if you would like us to make these changes.


> There's also the case that future ZONEMD schemes may need a different format for the digest field.   E.g. one approach to dealing with incremental changes is to have a NSEC like ZONEMD record which covers hashes only across a range of names.
> 


We think that the currently documented RR format will solve most use cases - since the digest field is variable length, it already provides a lot of flexibility for future uses, by defining additional Digest Types.  Anything which cannot be solved with this format seems like it would be a sufficiently different protocol that it would deserve a new RRtype and document. 

> So instead maybe change Digest Type -> Scheme type and   Parameter & Digest -> Scheme data (which is for this scheme just the digest data).
> 


Thank you, there are great suggestions, and we think make the document more readable / understandable.

DW