Re: [Gen-art] Gen-ART telechat review of draft-ietf-dnsop-delegation-trust-maintainance-13.txt (updated)

[Jari Arkko <[e-mail]>]

Thanks for the review, Brian, and thank you Warren and Olafur for answers. I do agree with the remaining issues as listed by Brian below; can I expect a new draft revision to address these?

Jari

On 06 Jun 2014, at 05:12, Brian E Carpenter <[e-mail]> wrote:

> I am the assigned Gen-ART reviewer for this draft. For background on
> Gen-ART, please see the FAQ at
> < http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> 
> Please wait for direction from your document shepherd
> or AD before posting a new version of the draft.
> 
> Document: draft-ietf-dnsop-delegation-trust-maintainance-13.txt
> Reviewer: Brian Carpenter
> Review Date: 2014-06-06
> IETF LC End Date: 2014-05-26
> IESG Telechat date: 2014-06-12
> 
> Summary:  Almost ready
> --------
> 
> Comment:
> --------
> 
> These are my Last Call comments on version -13. The authors responded
> with helpful explanations, and I understand that they plan some
> corresponding changes before publication.
> 
> Minor issues:
> -------------
> 
>> 1. Introduction
> ...
>> Any manual process is susceptible to mistakes and / or errors.
> 
> Also susceptible to social engineering or malicious leaks, I think.
> There's a fairly strong security argument for getting humans out
> of the process.
> 
>> 3. CDS / CDNSKEY (Child DS / Child DNSKEY) Record Definitions
> ...
>> it is up to the consumer of the records to
>> translate that into the appropriate add/delete operations in the
>> provisioning systems
> 
> Not clear here whether this is expected to be an automated or manual process.
> 
>> If no CDS / CDNSKEY RRset is present in child,
>> this means that no change is needed.
> 
> Not clear here how we ensure that update is performed exactly once. See below.
> 
>> 4. Automating DS Maintenance With CDS / CDNSKEY records
>> 
>> CDS / CDNSKEY resource records are intended to be "consumed" by
>> delegation trust maintainers.  The use of CDS / CDNSKEY is optional.
> 
> I think that could be OPTIONAL.
> 
>> The child SHOULD publish both CDS and CDNSKEY resource records.
> 
> Given the previous sentence, I think this needs to be
> 
> If the child publishes either the CDS or the CDNSKEY resource record, it
> SHOULD publish both.
> 
>> 4.1. CDS / CDNSKEY Processing Rules
> ...
>> If there are no CDS / CDNSKEY RRset in the child, this signals that
>> no change should be made to the current DS set.  This means that,
>> once the child and parent are in sync, the Child DNS Operator MAY
>> remove all CDS and CDNSKEY resource records from the zone.
> 
> Does that mean the the child MAY/SHOULD/MUST monitor what the
> parent is publishing in order to automate this process? If not, you
> are calling for a manual operation. (The text in section 5
> is repetitious, by the way, but still doesn't clarify this.)
> 
>> If any these conditions fail the CDS / CDNSKEY resource record MUST
>> be ignored.
> 
> Silently? Should this be logged? Any DOS potential here? Should use of
> these RRs be rate-limited in both child and parent to avoid any DOS risk?
> 
>> 6. Parent Side CDS / CDNSKEY Consumption
> 
> I don't think you specify what the parent should do if it receives
> both a CDS and a CDNSKEY and they are inconsistent (in violation
> of section 4). Yes, it's a corner case but Murphy's law always applies.
> 
>> 9. Security Considerations
> ...
>> While it may be tempting, this SHOULD NOT be used for initial
>> enrollment of keys since there is no way to ensure that the initial
>> key is the correct one.  If is used, strict rules for inclusion of
>> keys such as hold down times, challenge data inclusion or similar,
>> ought to be used, along with some kind of challenge mechanism.
> 
> Shouldn't that "ought to" be MUST? Weak protection against a bogus
> initial key really seems like a "Crypto Won't Save You Either" poster
> child.
> 
> Nits:
> -----
> 
> (from the shepherd's write-up)
> "The document references the document draft-ietf-dnsop-dnssec-key-timing, which had
> been approved for publication but never followed through on, and is shown to be expired."
> 
> This is an informational reference and could probably be deleted without harm.
> 
> "Additionally, the document references RFC2119 key word "NOT RECOMMENDED" without referencing it. "
> 
> That is a well known bug in RFC 2119 itself. The citation can be fixed as per
> http://www.rfc-editor.org/errata_search.php?eid=499
> 
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