The Network Endpoint Assessment (NEA) Asokan Attack Analysis
draft-ietf-nea-asokan-02

[Ballot comment]
The third sentence of the Introduction is an apparent non sequitur. It
would be nice if some context was given to the statement.

---

Section 5

  1. Protocols should make use of cryptographic binding, however
    binding identities of the tunnel endpoints in the EMA may be
    useful.

This is hard to parse. Is there an "also" missing from the second
clause?

[Ballot comment]
I have one point requiring clarification:

Section 2, paragraph 1:

>    The NEA Asokan Attack is a variation on an attack described in a
>    2002 paper written by Asokan, Niemi, and Nyberg [1]. Figure 1
>    depicts one version of the original Asokan attack. This attack
>    involves tricking an authorized user into authenticating to a decoy
>    AAA server, which forwards the authentication protocol from one
>    tunnel to another, tricking a AAA server into believing these
>    messages came from the attacker and granting access to him.

  Shouldn't it read that the 'believe that messages came from the user,
  but granting access to the attacker'?

[Ballot comment]
I had no idea what a Network Endpoint Assessment was, until I stumbled on the reference to RFC5209. It would be a good idea to move the reference up to the first line of the Introduction.

I kept meeting PT, but has no idea what that was until I found it in RFC5209. A sentence earlier in the text would be useful.

IANA has reviewed draft-ietf-nea-asokan-01, which is currently in
Last Call, and has the following comments:

IANA understands that, upon approval of this document, there are
no IANA Actions that need completion.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Subject: Last Call:  (NEA Asokan Attack Analysis) to Informational RFC


The IESG has received a request from the Network Endpoint Assessment WG
(nea) to consider the following document:
- 'NEA Asokan Attack Analysis'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
ietf@ietf.org mailing lists by 2012-09-26. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract


  The Network Endpoint Assessment protocols are subject to a subtle
  forwarding attack that has become known as the NEA Asokan Attack.
  This document describes the attack and countermeasures that may be
  mounted.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-nea-asokan/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-nea-asokan/ballot/


No IPR declarations have been submitted directly on this I-D.

(1) What type of RFC is being requested (BCP, Proposed Standard,
Internet Standard, Informational, Experimental, or Historic)? Why is
this the proper type of RFC? Is this type of RFC indicated in the title
page header?

Informational is requested and indicated in the title page header.

(2) The IESG approval announcement includes a Document
Announcement Write-Up. Please provide such a Document
Announcement Write-Up. Recent examples can be found in the
"Action" announcements for approved documents. The approval
announcement contains the following sections:

  Technical Summary:
The Network Endpoint Assessment protocols are subject to a
subtle forwarding attack that has become known as the NEA
Asokan Attack. This document describes the attack and
countermeasures that may be mounted.

  Working Group Summary:

The WG formed a design team in July 2010 with the goal of
recommending a general-purpose counter-measure that would
work for both of the PT protocols under specification in the WG.
The design team analysis and recommendation is the subject
of this document. The recommendation of the design team was
presented to the WG at the IETF meeting in November 2010
where it received solid support. The result was confirmed on the
mailing list in January 2011, and the recommended counter-
measure subsequently incorporated into the two PT protocols
specified in the NEA WG. The two PT protocols, PT-TLS and PT-
EAP, are separately specified in two standards-track documents,
and reference this document as an Informative reference.

  Document Quality:
This document does not specify a protocol. Rather, it describes
counter-measures that PT-TLS and PT-EAP can use to mitigate
against the NEA Asokan attack. The PT-TLS and PT-EAP
specifications describe how these counter-measures should be used
in these particular protocols. As described above,  this
document is the result of active participation from several WG
members and received substantive review from the WG.

  Personnel:
Susan Thomson is the Document Shepherd. Stephen Farrell is
the Responsible Area Director.

(3) Briefly describe the review of this document that was performed by
the Document Shepherd. If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.

I have reviewed the document and do not have issues with it.

(4) Does the document Shepherd have any concerns about the depth
or breadth of the reviews that have been performed?

No.

(5) Do portions of the document need review from a particular or from
broader perspective, e.g., security, operational complexity, AAA, DNS,
DHCP, XML, or internationalization? If so, describe the review that took
place.

No broader review is known to be needed.

(6) Describe any specific concerns or issues that the Document
Shepherd has with this document that the Responsible Area Director
and/or the IESG should be aware of? For example, perhaps he or she
is uncomfortable with certain parts of the document, or has concerns
whether there really is a need for it. In any event, if the WG has
discussed those issues and has indicated that it still wishes to advance
the document, detail those concerns here.

No concerns. The attack and the need for a counter-measure was
thoroughly vetted within the NEA WG.

(7) Has each author confirmed that any and all appropriate IPR
disclosures required for full conformance with the provisions of BCP 78
and BCP 79 have already been filed. If not, explain why?

Yes.

(8) Has an IPR disclosure been filed that references this document? If
so, summarize any WG discussion and conclusion regarding the IPR
disclosures.

No.

(9) How solid is the WG consensus behind this document? Does it
represent the strong concurrence of a few individuals, with others
being silent, or does the WG as a whole understand and agree with it?

There is strong consensus from the WG. The attack itself was reviewed
within the WG at multiple IETF meetings, and the recommendation for
a counter-measure made by the design team received strong
consensus and has been incorporated into the relevant PT
specifications.

(10) Has anyone threatened an appeal or otherwise indicated extreme
discontent? If so, please summarise the areas of conflict in separate email
messages to the Responsible Area Director. (It should be in a separate
email because this questionnaire is publicly available.)

No.

(11) Identify any ID nits the Document Shepherd has found in this
document. (See http://www.ietf.org/tools/idnits/ and the Internet-
Drafts Checklist). Boilerplate checks are not enough; this check needs
to be thorough.

None. Idnits tool flags no issues.

(12) Describe how the document meets any required formal review
criteria, such as the MIB Doctor, media type, and URI type reviews.

Not Applicable.

(13) Have all references within this document been identified as either
normative or informative?

Yes. All references are informative.

(14) Are there normative references to documents that are not ready
for advancement or are otherwise in an unclear state? If such
normative references exist, what is the plan for their completion?

No. There are no normative references.

(15) Are there downward normative references (see RFC 3967)? If so,
list these downward references to support the Area Director in the Last
Call procedure.

No.

(16) Will publication of this document change the status of any
existing RFCs? Are those RFCs listed on the title page header, listed in
the abstract, and discussed in the introduction? If the RFCs are not
listed in the Abstract and Introduction, explain why, and point to the
part of the document where the relationship of this document to the
other RFCs is discussed. If this information is not in the document,
explain why the WG considers it unnecessary.

No.

(17) Describe the Document Shepherd's review of the IANA
considerations section, especially with regard to its consistency with
the body of the document. Confirm that all protocol extensions that
the document makes are associated with the appropriate reservations
in IANA registries. Confirm that any referenced IANA registries have
been clearly identified. Confirm that newly created IANA registries
include a detailed specification of the initial contents for the registry,
that allocations procedures for future registrations are defined, and a
reasonable name for the new registry has been suggested (see RFC
5226).

Not applicable. The document specifies no actions for IANA.

(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find
useful in selecting the IANA Experts for these new registries.

Not applicable. The document specifies no actions for IANA.

(19) Describe reviews and automated checks performed by the
Document Shepherd to validate sections of the document written
in a formal language, such as XML code, BNF rules, MIB
definitions, etc.

Not applicable. None of the document is written in a formal
language.