Re: [DNSOP] New Version Notification for draft-yorgos-dnsop-dry-run-dnssec-01.txt

[George Thessalonikefs <[e-mail]>]

Hi Libor,

Thanks for the time and feedback!

If you prefer the dry-run DS to have a static length maybe then you are 
more interested in the dry-run equivalent algorithm per actual algorithm 
timeline?

It would be interesting to know if your concern for static length arises 
from a registry point of view (as also mentioned in section 5.1.1), or 
something else.

Although security is unlikely to be an issue currently, it still means 
that whichever number we choose today may not work in the future.
If collisions could happen then a dry-run zone could be spoofed.
Although that would not matter for the DNSSEC adoption case as the zone 
was unsigned in the first place, the other cases (sections 3.1.2 and 
3.1.3) would weaken the security of an already DNSSEC signed zone.

But apart from security, I am also worried about the extra steps needed 
to handle the contents of the DS record and using it for DNSSEC (need to 
also crop/stretch the key digests while validating).
I would prefer the DNSSEC part to be mostly intact when dry running so 
that there is confidence on the reported results and expect the same 
behavior when advancing from a dry-run state.

Do my concerns make sense?

Best regards,
-- Yorgos

On 13/07/2022 13:26, libor.peltan wrote:
> Hi Willem, Yorgos, Roy, dnsop,
> I dare to repeat my support for the ideas in dry-run-dnssec draft.
> However, I still don't like the suggested format of dry-run DS record.
> Another alternative idea: how about putting the Digest Type into the 
> first octet of Digest field like in the draft, but cropping (or 
> stretching) the rest of the actual digest in a way that the overall size 
> of the resulting Digest field is something "normal" (e.g. 32 octets), 
> and does not differ based on actual Digest Type? I assume that for 
> dry-run, the weakened actual security of cropped Digest is not a big deal.
> Please consider my thought and employ/deny it as needed.
> Best,
> Libor
> 
> Dne 12. 07. 22 v 16:35 Willem Toorop napsal(a):
>> Dear dnsop,
>>
>> We submitted a new version of a “dry-run DNSSEC” draft. The draft
>> describes a method that allows for testing DNSSEC deployments in real
>> world DNS(SEC) deployments without affecting the DNS service in case of
>> DNSSEC errors. Any encountered errors are signaled to the DNS operator
>> of the faulty zone with DNS Error Reporting
>> (draft-ietf-dnsop-dns-error-reporting).
>>
>> This is a new idea which will be presented during dnsop at the IETF114
>> and was also presented at the IETF113. A recording of the IETF113
>> presentation is here: https://youtu.be/watch?v=7HxcmvFOnlU&t=3675s
>> Slides here:
>> https://datatracker.ietf.org/meeting/113/materials/slides-113-dnsop-dry-run-dnssec-01 
>>
>>
>> We received a lot of feedback with our presentation which we used to
>> reorganize the draft to convey the idea more clearly and coherently. We
>> also received some critique and objections which were non-technical in
>> nature. Below is a list with these objections followed by our response.
>>
>> ** This is another straw on the camel’s back **
>>
>> Not all resolvers have to support/implement it. Most important is that
>> provisioning at the registry and signaling of Dry-run is supported. If
>> needed we can say it is OPTIONAL for resolvers in the draft. We intend
>> to implement it ourselves in Unbound and have it enabled by default when
>> error reporting is enabled. We know from experience with trust-anchor
>> signaling and sentinel record that with only a small, up to date
>> resolver population, the signaling is already quite substantial.
>>
>> There are different kinds of straws and this one is one that has the
>> good cause of enabling operators to deploy DNSSEC with confidence.
>>
>>
>> ** Why not have a duplicate parallel test deployment? **
>>
>> There is nothing better than testing with your actual user population to
>> dry-run your DNSSEC deployment. Note that slack’s parallel test
>> deployment did not show them the Route53 failure that caused them to
>> have an DNSSEC outage eventually[1]
>>
>>
>> ** Why not sell DNSSEC domains cheaper? **
>>
>> Yes, we’re all for that too, but that’s orthogonal to seeing what the
>> actual effect of starting DNSSEC with your deployment with your real
>> user population would be.
>>
>>
>> The other objections which were more technical, like for example
>> “registries supporting only fixed sized hashes per algorithm” and
>> “couldn’t we normalize the different DS hacks somehow” are all addressed
>> in the new version of the document.
>>
>> We’re looking forward to a new round of feedback and critique ;)
>> Both on-list and in-person at the IETF-114!
>>
>> Kind regards,
>>
>> Yorgos, Willem and Roy
>>
>>
>> Op 11-07-2022 om 23:58 schreef [e-mail]:
>>> A new version of I-D, draft-yorgos-dnsop-dry-run-dnssec-01.txt
>>> has been successfully submitted by Yorgos Thessalonikefs and posted 
>>> to the
>>> IETF repository.
>>>
>>> Name:        draft-yorgos-dnsop-dry-run-dnssec
>>> Revision:    01
>>> Title:        dry-run DNSSEC
>>> Document date:    2022-07-11
>>> Group:        Individual Submission
>>> Pages:        12
>>> URL:            
>>> https://www.ietf.org/archive/id/draft-yorgos-dnsop-dry-run-dnssec-01.txt
>>> Status:         
>>> https://datatracker.ietf.org/doc/draft-yorgos-dnsop-dry-run-dnssec/
>>> Html:           
>>> https://www.ietf.org/archive/id/draft-yorgos-dnsop-dry-run-dnssec-01.html 
>>>
>>> Htmlized:       
>>> https://datatracker.ietf.org/doc/html/draft-yorgos-dnsop-dry-run-dnssec
>>> Diff:           
>>> https://www.ietf.org/rfcdiff?url2=draft-yorgos-dnsop-dry-run-dnssec-01
>>>
>>> Abstract:
>>>     This document describes a method called "dry-run DNSSEC" that allows
>>>     for testing DNSSEC deployments without affecting the DNS service in
>>>     case of DNSSEC errors.  It accomplishes that by introducing a new DS
>>>     Type Digest Algorithm that signals validating resolvers that dry-run
>>>     DNSSEC is used for the zone.  DNSSEC errors are then reported with
>>>     DNS Error Reporting, but any bogus responses to clients are 
>>> withheld.
>>>     Instead, validating resolvers fallback from dry-run DNSSEC and
>>>     provide the response that would have been answered without the
>>>     presence of a dry-run DS.  A further option is presented for clients
>>>     to opt-in for dry-run DNSSEC errors and allow for end-to-end DNSSEC
>>>     testing.
>>>
>>>
>>>
>>> The IETF Secretariat
>>>
>>>
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