[ietf-dkim] Consensus check: Domain Existence Check

[Steve Atkins]

On May 29, 2008, at 2:45 AM, Stephen Farrell wrote:

>
> There has been considerable debate in the past few weeks regarding the
> need for a check for domain existence in ADSP.
>
> I think we've had sufficient time for debating this, let's decide.
> Please respond to this by Friday June 6th.
>
> The text in question (from section 4.2.2 of draft-ietf-dkim-ssp-03)
> is as follows:
>
>   2.  _Verify Domain Exists._ The host MUST perform a DNS query for a
>       record corresponding to the Author Domain (with no prefix).  The
>       type of the query can be of any type, since this step is only to
>       determine if the domain itself exists in DNS.  This query MAY be
>       done in parallel with the query made in step 2.  If the result  
> of
>       this query is an "NXDOMAIN" error, the algorithm MUST terminate
>       with an appropriate error.
>
>          NON-NORMATIVE DISCUSSION: Any resource record type could be
>          used for this query since the existence of a resource record
>          of any type will prevent an "NXDOMAIN" error.  MX is a
>          reasonable choice for this purpose is because this record  
> type
>          is thought to be the most common for likely domains, and will
>          therefore result in a result which can be more readily cached
>          than a negative result.
>
> There are three options that have been actively discussed:

Modify.

(I might be talked into "keep", but "remove" would be a complete
non-starter.)

Cheers,
   Steve