Subject: Re: rrsig(qtype)

From: Derek Atkins <[email-masked]>
Date: Thu, 17 Jun 2004 10:33:17 -0400

Can you be more explicit about what's actually signed in this
proposal?  You clearly need to make the signature bound to the actual
asked question.  But "sign(RRSIG_RDATA)" is not sufficient in my mind
to explain what's included in the signature in this response, nor
sufficient to bind the RRSIG to this particular question.

I do like this approach....

-derek

Roy Arends <[email-masked]> writes:

> This is an alternative online signing proposal:
>
> Deny existence for QTYPE,QNAME,QCLASS by responding with empty answer
> section and RRSIG in authority section, which is dynamically generated and
> has signature field value: sign(RRSIG_RDATA).
>
> example:
>
> Dynamic No Data Error
>
>    A "NODATA" response.  The RRSIG proves that the requested RR type does
>    not exist.
>
>    ;; Header: QR AA DO RCODE=0
>    ;;
>    ;; Question
>    mail.example.     IN MX
>
>    ;; Answer
>    ;; (empty)
>
>    ;; Authority
>    mail.example. 600 IN RRSIG  MX 5 1 600 20040609183619 (
>                                20040609183019 37223 example.
>                                ONx0k36rcjaxYtcNgq6iQnpNV5+drqYAsC9h
>                                ..
>                                jV7j86HyQgM5e7+miRAz8V01b0I= )
>
>    ;; Additional
>    ;; (empty)
>
> Roy

-- 
       Derek Atkins                 617-623-3745
       [email-masked]             www.ihtfp.com
       Computer and Internet Security Consultant

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---

From: Roy Arends <[email-masked]>
Date: Thu, 17 Jun 2004 17:06:45 +0200 (CEST)

> sufficient to bind the RRSIG to this particular question.

Sign(RRSIG_RDATA) assumed that owner name was a field in RRSIG_RDATA,
which is not the case.  I should have said sign(RRSIG_RDATA | QNAME |
QCLASS) where RRSIG_RDATA is the wire format of the RRSIG RDATA fields
with the Signer's Name field in canonical form and the Signature field
excluded. This RRSIG RDATA has QTYPE in the type covered field.

Presented as said in my previous mail (empty answer, rrsig in auth), it
can then be interpreted as an authenticated denial for
QNAME,QTYPE,QCLASS.

Roy

---

From: Derek Atkins <[email-masked]>
Date: Thu, 17 Jun 2004 11:21:53 -0400

> can then be interpreted as an authenticated denial for

Thank you.  I believe that sign(RRSIG_RDATA | QNAME | QCLASS) does
provide an authenticated denial for QNAME/QTYPE/QCLASS because it'll
be a sig over empty data, but still depend on the name/type/class.

I'm certainly in favor of this proposal.

-derek

---

From: Roy Arends <[email-masked]>
Date: Thu, 17 Jun 2004 17:32:26 +0200 (CEST)

On Thu, 17 Jun 2004, Derek Atkins wrote:

> I'm certainly in favor of this proposal

Okay, d'you think it is appropriate for -trans ?

Roy

---

From: Derek Atkins <[email-masked]>
Date: Thu, 17 Jun 2004 11:55:34 -0400

> Okay, d'you think it is appropriate for -trans ?

If -trans is suggesting real-time signatures for people who don't want
NSEC, then yes I think it's appropriate for -trans.  Does it require
any changes to bis for proper resolver interpretation of this answer?
(I believe the answer to this question is "no", but it's something
that needs to be asked).

-derek

---

From: Roy Arends <[email-masked]>
Date: Thu, 17 Jun 2004 18:21:47 +0200 (CEST)

On Thu, 17 Jun 2004, Derek Atkins wrote:

> NSEC, then yes I think it's appropriate for -trans.

Yes. -trans is suggesting real-time signatures as a measure against
zone-traversal until dnssec-ter has arrived. For the rest, there is
dnssec-ter, or the DoNothing option.

> Does it require any changes to bis for proper resolver interpretation of
> this answer? (I believe the answer to this question is "no", but it's
> something that needs to be asked).

Well, hmmm,  it is a response-type that dnssec-bis resolvers do not yet
swallow. I think the changes to -bis are minimal to allow this.

Roy

---

From: "Scott Rose" <[email-masked]>
Date: Thu, 17 Jun 2004 12:31:36 -0400

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Derek Atkins
>
>

I believe it does require some spec change.  Now RRSIGs are being used to
provide non-existent responses, instead of just providing origin
authentication and data integrity.   Not major overhauls, but changes.

And signaling non-signed delegations might need some clarification (if this
scheme is used).  It would look something like this (if I am not mistaken):

Question:  www.example.com

Ans:

Auth:
	example.com.    NS  somehost
	example.com   RRSIG(DS)  signer-.com
Add:
	somehost  	A	10.10.10.1

It sounds like an possibly viable option.  One that could be added to the
DNSSECbis->DNSSECter draft.

Scott

---

From: "Olaf M. Kolkman" <[email-masked]>
Date: Fri, 18 Jun 2004 10:31:13 +0200

On Thu, 17 Jun 2004 09:28:32 +0200 (CEST)

> This is an alternative online signing proposal:

Please move this to [email-masked] and report back to namedroppers
when the idea has been cooked and the changes in the security model
are ironed out.

Please concentrate on DNSSEC-bis and the possible minor changes that
are needed in the light of allowing _a_ viable transition. 

Even though this alternative is related to trans we should try not to
widen the discussion by introducing new ideas that need in depth
analysis.

The question on the table is can DNSSEC-bis be shipped without
closing the door &c &c &c

-- Olaf
   DNSSEXT Co-Chair

---------------------------------| Olaf M. Kolkman
---------------------------------| RIPE NCC