On Dec 1, 2014, at 5:29 PM, Paul Vixie <[email protected]> wrote:
> i think you meant "zone" not "root zone" here.

I meant "root zone" because I have heard nearly no one talk about verifying 
other zones. If what is created works for other zones, great.
>> 
>> A signed hash meets (2) regardless of how the zone was transmitted.
> 
> not inevitably. the verification tool would be new logic, either built into 
> the secondary name server, or as an outboard tool available to the transfer 
> mechanism.

Others on this list have asked for a third use case, namely zone files sitting 
on disk.

>  when i compare the complexity-cost of that tool to the contents of the 
> <ftp://ftp.internic.net/domain> directory, i see that existing tools whose 
> complexity-cost i already pay would work just fine. (those being pgp and 
> md5sum). so, a detached signature can in some cases meet (2) far more easily 
> than an in-band signature.

Your proposal skips over the "how do I trust this signing key" part. You might 
want to force everyone else to do the work you have done to get to that trust; 
others might want a simpler solution.

> it's also the case that rsync and similar tools (and AXFR) use TCP which most 
> of us consider "reliable" even though its checksums aren't nearly as strong 
> as SCTP's. therefore your problem statement "being sure they got the exact 
> right zone" would have to refer to an MiTM, possibly inside the secondary 
> server (if the zone receiver is a tertiary), or possibly on-path.

Yes.

> in either case, to frustrate the MiTM, the proposed in-band signature would 
> have to be DNSSEC based.

No offense, but you're making no sense. Above, you give a counter-example to 
that assertion.

> and there is already an in-band DNSSEC-based zone identity/coherency test -- 
> zone walking. why would we add another way to do the same thing we could do 
> with existing DNSSEC data?

Maybe I'm just being dense, but I'm not seeing how zone walking validates the 
contents of the glue records.

> i think walking the existing zone and verifying that there are no records 
> between the nsecs and that every signature is valid and that the nsec chain 
> ends at the apex, is simpler.

It is. Unless I'm missing something, it is also incomplete.

(And, of course, doesn't work for zones that use NSEC3...)

--Paul Hoffman
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