On Apr 1, 2015, at 2:13 PM, Nico Williams <[email protected]> wrote:

> On Wed, Apr 01, 2015 at 01:17:15AM -0000, John Levine wrote:
>>> An alternative is to go back to the original base32 encoding, which
>>> is lossless, and thus can allow the remote DNS server (a special-purpose
>>> DNS lookup engine serving a zone with per-user information) to
>>> decode the local-part and perform whatever fuzzy matching may be
>>> appropriate.
>>> 
>>> The lossless encoding can support longer names by breaking them up
>>> into multiple labels.
>>> 
>>> This allows static DNS to be published where desired, and custom
>>> code to produce dynamic results when appropriate.
>> 
>> I wrote up a draft summarizing the ways one might do mailbox
>> name lookups in the DNS with something close to the local-part
>> rules that MTAs have:
>> 
>> http://datatracker.ietf.org/doc/draft-levine-dns-mailbox/
> 
> The All Names Valid approach has a problem: we're looking for S/MIME or
> OPENPGP public keys, so that's what needs to be found.  For any public
> key algorithms where not every possible bit string is a possible public
> key, and where clients can figure that out, the server would have to
> generate distinct plausible public keys, otherwise clients could still
> enumerate the set of plausible mailboxes.
> 
> I would still prefer to require MUAs to implement the DNS
> (base32-encoded) LHS lookup and the pointer-to-HTTPS-server lookup.
> Whether mail domains choose to implement static or dynamic DNS lookups,
> or the pointer-to-HTTPS-server, should be up to them.

Following up on an earlier comment: by adding a URI field to the SMIMEA RR (and 
keeping the CAD for verification on the other end), zone admin/operators can 
add an RR at the apex of their zone, that points to another service, secure the 
delegation with the CAD material, and then (optionally) add per-inbox RRs (also 
possibly using URI pointers) in their zone.  This would also let domains 
experiment with oracle-like-services in a compatible way with direct key 
learning from mailboxes, me thinks. :)

<snip>

Eric
_______________________________________________
dane mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dane

Reply via email to