Re: [dns-privacy] Working Group Last Call for draft-ietf-dprive-bcp-op

[Stephen Farrell <[e-mail]>]

Hiya,

I had an hour so gave this a read. I like the draft
but think it's not ready quite yet. Depending on the
answer to my question at #1 below, that could all be
fixed before or just after the end of the WGLC though
but it might take a bit longer as there's more than a
teeny bit of work needed I'd say.

Substantive comments and nits below.

Cheers,
S.


#1: I wonder would we be better to wait until some real
operators have published DPPPS documents before making
this an RFC? I'd expect that there'll be some changes
when/if that happens (I'm assuming it's not yet happened
but didn't check.) If some such operator has said they'd
do that, but want to wait 'till there's an RFC, then
that's a good enough reason to go ahead now. If we just
don't know, then going ahead and recording this in an
RFC is probably ok, but risks this not being followed
much or at all.

#2: I think a sample DPPPS document should at least
exist and be referenced from this or included as an
appendix. Is there one somewhere? If not, then I think
we really ought fix that before publication.

#3: Perhaps we should ask the pearg and httpbis folks if
there's any more/better guidance to add to 5.1.3.2?
IIRC a pearg presentation at IETF105 seems to have
indicated that some h2 session management stuff might
also assist with traffic analysis. Checking that out
before publication would seem worthwhile in case there's
more to usefully say here.

#4: 5.1.4: the lowercase "must" for DNSSEC validation is
odd. I'd like a "MUST" but perhaps that's not feasible
now?

#5: given that 1% of zones are signed, and that DNSSEC
answers are big, do we think padding is sufficient to
prevent an observer from knowing when a qname is in the
1%? If so, great! (But really?;-) If not, is that a
problem worth mentioning? And is there anything one could
do about it?

#6: I don't think mention of "consent" is a good thing
to positively recommend operators do as there is (afaik)
no good way to really do that. The idea that whatever is
behind a DNS stub client can meaningfully "consent" to
something is really just broken IMO.  (Mentioning that
one cannot assume consent is fine, but saying to go get
it, when that makes no sense, isn't fine IMO.) Same
applies to 6.1.1 item 7.

#7: 6.1.1, item 3: "sold or rented" - heh - good luck
with that;-) Why not just say doing that's a "MUST NOT"?
What operator adhering to this BCP would really be
selling or renting the data? I would hope none, and that
the BCP calls that out as non-conforming.

#8: 6.1.1, item 6: That all looks too heavy to actually
be done by any of the bigger folks who use anycast - are
we really expecting them to list all the local laws that
might apply?  What use would that be to someone
selecting an operator really? While some information
about jurisdictions ought be part of this, I think that
needs more thought.

nits:

- abstract: Is "DNS operators" right? Maybe this is
  really just "DNS recursive resolver operators" and
doesn't include advice for authoritative server
operators? Probably better to have the abstract
correct.

- DPPPS: that's not a great term, hard to say and hard
to remember how many P's - I'd suggest a bit of creative
bacronyming might be worthwhile - I'll start the bikeshed
painting with "DNS Recursive Operator Privacy statement"
or "DROP statement":-)

- I don't understand the bullet list just before section
  5.1, nor the preceding paragraph - what's it trying
to say?

- 5.1.2: X.509 probably needs a reference to rfc5280,
  but where do I go to find a definition of an "SPKI
pinset"? Later you point to rfc7858 for that but I don't
find the term "pinset" used in there - "pin set" (with a
space) is used in appendix A there, so maybe that's the
reference you want.

- 5.1.2: (sadly) maybe it'd be better to remove the
  mention of the DNSSEC chain extension draft. I suspect
it'd just confuse readers of an RFC later.

- 5.1.2: Is anyone publishing TLSA for DoT/DoH servers?
  If so, great! If not, "can also consider" mightn't be
worth saying.

- 5.1.3.1: the link at [1] seems broken? I didn't check
  all others, but someone should:-)

- 5.1.3.1: Maybe say using RFC8467 or a successor
  specification? It's pretty early days to be very
confident in that RFC. (Much though I like it.)

- 5.1.7: Is "Operator" in the section heading here
  really the operator of the DNS privacy service?
Better to be clear about that. People might think you
mean n/w operators between the stub and recursive.

- 5.2.3: The content of [10] really needs to be in the
  document body, or else the text above it needs to
change.

- 5.3.1: The "NOTE" that the authors may add something
  later needs fixing.

- 5.3.2: The "pitfalls" link reference is broken I
  think.

- 6.1.1, item 2: add "and for how long and how those
  logs are handled" (and maybe more) - this bullet also
overlaps with item 3, so maybe it'd be better to
re-organise this list a bit?

- section 8: A "TODO" there isn't gonna work really:-)