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

Jari, 
we will push one out today 

	Olafur

On Jun 10, 2014, at 8:30 AM, Jari Arkko <jari.arkko@ericsson.com> wrote:

> 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 <brian.e.carpenter@gmail.com> 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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> 