Re: [DNSOP] [Technical Errata Reported] RFC8078 (5049)

[Dick Franks <[e-mail]>]

 On 24 June 2017 at 16:45, Ondřej Caletka <[e-mail]> wrote:

>8

The result that made it to the RFC is that there should be indeed one
> byte with value of 00 in the Digest/Public key field instead of no data
> at all.


That does not appear to be the position at all.

RFC8078 mandates a specific presentation format notation for the entire
RDATA string whenever algorithm is zero, and irrespective of actual values
in other fields.

The RFC is conspicuously silent about the equivalent wire-format
representation.


This avoids the need of defining new format and updating all the
> deployed software. It's not only about parsers of the wire format but
> also about zone file parsers, that would need an update as the single
> zero is not conformant with currently defined presentation format of
> CDS/CDNSKEY RRs.
>

It is clear from the text of draft-ietf-dnsop-maintain-ds-04 that the
notion of mandated presentation format notation was already present.
Moreover, that version also carried the warning:

    This is a change in format from strict interpretation of
    [RFC7344] and may cause problems with some deployed software.

Your primary argument was therefore a non-starter even before the
appearance of the unparseable single zero.


I believe changing RRdata format just for this one purpose would add an
> unnecessary complexity.
>
> That train has already left the station.