Re: [DNSOP] New Version Notification for draft-wessels-dns-zone-digest-01.txt

[Florian Weimer <[e-mail]>]

* John R. Levine:

> On Sat, 28 Jul 2018, Florian Weimer wrote:
>> A malicious server might never stop sending data, or claim that the
>> transfer is ridiculously large.  If the zone digest does not include
>> information about the amount of data, this can only be detected after
>> the server ended transmission, at which time the ZONEMD digest can be
>> compared.  But at this point, the client may already have filled its
>> storage with garbage data, unless the double transfer trick is used.
>
> I realize that hypothetically a malicious server could send you a large 
> file of garbage.  But that can happen any time you downlaod a file from 
> anywhere.  It doesn't strike me as something that needs special hackery 
> for this rather specific case.

A lot of other updaters use HTTPS, which does not have this issue if
the terminating party is also the source of the data.  Those that do
not use other mechanisms.  There is quite a bit of previous work in
this area (see <https://theupdateframework.github.io/> for specific
take on this subject), and the current ZONEMD draft does not
acknowledge this, even though its goals are broadly similar.