Distribution of EAP-Based Keys for Handover and Re-Authentication
draft-ietf-hokey-key-mgm-13

[Ballot comment]
Section 5 says that "the local ER server requesting the DSRK MUST
include a KDE-Request in the first EAP-Response message from the
peer".  I don't think this "MUST" serves any useful purpose in this
document (and rules out perfectly valid design choices); where and
how exactly KDE-Request is sent will be anyway specified in the
concrete ERP-over-RADIUS or -Diameter specification.

[Ballot discuss]
I have reviewed draft-ietf-hokey-key-mgm-09, and have couple of
concerns/questions that I'd like to discuss before recommending
approval of the document:

- After reading the abstract ("The document defines a key distribution
exchange (KDE) protocol that can distribute these different types of
root keys..."), I was expecting that this document would define a
protocol (message formats and their processing).

But the document never does that -- it's more like "high-level design
for a protocol to be defined in the future".  Earlier versions of this
draft actually included message formats, but it seems the were removed
-- but the abstract and introduction were not updated to reflect
this rather major change.

- Since you cannot actually implement this document (and thus can't
have two interoperable implementations), does it even belong on
Standards Track?

- Section 5 has a MUST-level requirement that's probably a leftover
from times when this still defined a protocol: "the local ER server
requesting the DSRK MUST include a KDE-Request message in the first
EAP-Response message from the peer."

[Ballot discuss]
I have reviewed draft-ietf-hokey-key-mgm-09, and have couple of
concerns/questions that I'd like to discuss before recommending
approval of the document:

- After reading the abstract ("The document defines a key distribution
exchange (KDE) protocol that can distribute these different types of
root keys..."), I was expecting that this document would define a
protocol (message formats and their processing).

But the document never does that -- it's more like "high-level design
for a protocol to be defined in the future".  Earlier versions of this
draft actually included message formats, but it seems the were removed
-- but the abstract and introduction were not updated to reflect
this rather major change.

- Since you cannot actually implement this document (and thus can't
have two interoperable implementations), does it even belong on
Standards Track?

- Section 5 has a MUST-level requirement that's probably a leftover
from times when this still defined a protocol: "the local ER server
requesting the DSRK MUST include a KDE-Request message in the first
EAP-Response message from the peer."

[Ballot discuss]
This was a well written document, and I was about to vote Yes on it.
However, before recommending the approval I would like you to help
me understand this:

  The encoding of the key type is left to the discretion of
  the implementer.

Yet, the document is scheduled to become a Proposed Standard, and later
in the document you talk about the encoding of at least some fields
in AAA protocols (PID = User-Name etc). To what extent does is this
specification complete? What else is there missing than the KT field?
Or, if there are missing things, why is this a proposed standard,
wouldn't an informational specification that gives a general outline
of an approach be more suitable?

[Ballot comment]
I noticed that the PROTO write-up includes the following:

>My only concern is whether the document should be on the Standards track or
>if BCP would be a better classification: the original document was less
>abstract & more RADIUS-specific & so Standards Track made some sense; I'm
>not so sure about this version. 

I actually am quite confortable with this document being approved as PS, because it does define a mechanism that involves interoperability on the wire. It would be good however for the IESG to consider again this issue before approval.

[Ballot comment]
AAA is not an RFC Editor "well-known" abbrevation, and should be
expanded in the Abstract and on first use in the main text. You
might also add it to section 2.

[Ballot comment]
In the Gen-ART Review by Francis Dupont on 2009-07-30, it was suggested:

    I understand this specification is very abstract about on wire
    entities (for instance there is nothing about encoding, etc) but
    this can become an issue about key labels, i.e., the reader has
    to read the (referenced) RFC 5295 if (s)he wants to know what are
    exactly these key labels (note the term "label" can denote many
    different things). I suggest to be slightly more reader friendly,
    for instance by writing the RFC 5295 establishes a IANA registry
    for "USRK Key Labels" too:
   
    for the specification of key labels -> ... and associated IANA registry.

[Ballot comment]
The following 2 references don't look like Normative references:

  [RFC2865]  Rigney, C., Willens, S., Rubens, A., and W. Simpson,
              "Remote Authentication Dial In User Service (RADIUS)",
              RFC 2865, June 2000.

  [RFC3588]  Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
              Arkko, "Diameter Base Protocol", RFC 3588, September 2003.

The hokey WG requested the publication of Distribution of EAP based keys for
>handover and re-authentication
>(http://www.ietf.org/internet-drafts/draft-ietf-hokey-key-mgm-08.txt) as a
>Proposed Standard RFC.  The proto write-up follows.
>
>
>    (1.a) Who is the Document Shepherd for this document? Has the
>          Document Shepherd personally reviewed this version of the
>          document and, in particular, does he or she believe this
>          version is ready for forwarding to the IESG for publication?
>Glen Zorn is the document shepherd.  He has personally reviewed the document
>and believes that it is ready to be forwarded to the IESG.
>
>    (1.b) Has the document had adequate review both from key WG members
>          and from key non-WG members? Does the Document Shepherd have
>          any concerns about the depth or breadth of the reviews that
>          have been performed?
>Adequate review, no concerns.
>
>    (1.c) Does the Document Shepherd have concerns that the document
>          needs more review from a particular or broader perspective,
>          e.g., security, operational complexity, someone familiar with
>          AAA, internationalization or XML?
>No.
>
>    (1.d) Does the Document Shepherd have any specific concerns or
>          issues 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. Has an IPR disclosure related to this document
>          been filed? If so, please include a reference to the
>          disclosure and summarize the WG discussion and conclusion on
>          this issue.
>My only concern is whether the document should be on the Standards track or
>if BCP would be a better classification: the original document was less
>abstract & more RADIUS-specific & so Standards Track made some sense; I'm
>not so sure about this version.  No IPR disclosures have been made.
>
>    (1.e) 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?
>The WG has been asked to review the document.  A few issues were raised and
>dealt with.  The WG Chairs did not attempt to force the WG members to
>specifically approve of the document, preferring to rely upon the
>millenia-old convention that silence signifies assent.
>
>    (1.f) 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
>          entered into the ID Tracker.)
>No.
>
>    (1.g) Has the Document Shepherd personally verified that the
>          document satisfies all ID nits? (See
>          http://www.ietf.org/ID-Checklist.html and
>          http://tools.ietf.org/tools/idnits/). Boilerplate checks are
>          not enough; this check needs to be thorough. Has the document
>          met all formal review criteria it needs to, such as the MIB
>          Doctor, media type and URI type reviews?
>Yes.
>
>    (1.h) Has the document split its references into normative and
>          informative? 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
>          strategy for their completion? Are there normative references
>          that are downward references, as described in [RFC3967]? If
>          so, list these downward references to support the Area
>          Director in the Last Call procedure for them [RFC3967].
>The references look fine.
>
>    (1.i) Has the Document Shepherd verified that the document IANA
>          consideration section exists and is consistent with the body
>          of the document? If the document specifies protocol
>          extensions, are reservations requested in appropriate IANA
>          registries? Are the IANA registries clearly identified? If
>          the document creates a new registry, does it define the
>          proposed initial contents of the registry and an allocation
>          procedure for future registrations? Does it suggest a
>          reasonable name for the new registry? See [RFC5226]. If the
>          document describes an Expert Review process has Shepherd
>          conferred with the Responsible Area Director so that the IESG
>          can appoint the needed Expert during the IESG Evaluation?
>The document makes no demands upon the IANA.
>
>    (1.j) Has the Document Shepherd verified that sections of the
>          document that are written in a formal language, such as XML
>          code, BNF rules, MIB definitions, etc., validate correctly in
>          an automated checker?
>N/A.
>
>    (1.k) 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
>              Relevant content can frequently be found in the abstract
>              and/or introduction of the document. If not, this may be
>              an indication that there are deficiencies in the abstract
>              or introduction.
>          Working Group Summary
>              Was there anything in WG process that is worth noting? For
>              example, was there controversy about particular points or
>              were there decisions where the consensus was particularly
>              rough?
>          Document Quality
>              Are there existing implementations of the protocol? Have a
>              significant number of vendors indicated their plan to
>              implement the specification? Are there any reviewers that
>              merit special mention as having done a thorough review,
>              e.g., one that resulted in important changes or a
>              conclusion that the document had no substantive issues? If
>              there was a MIB Doctor, Media Type or other expert review,
>              what was its course (briefly)? In the case of a Media Type
>              review, on what date was the request posted?
>Technical Summary
>    This document describes a mechanism for delivering root keys from an
>    Extensible Authentication Protocol (EAP) server to another network
>    server that requires the keys for offering security protected
>    services, such as re-authentication, to an EAP peer.  The distributed
>    root key can be either a usage-specific root key (USRK), a domain-
>    specific root key (DSRK) or a domain-specific usage-specific root key
>    (DSUSRK) that has been derived from an Extended Master Session Key
>    (EMSK) hierarchy previously established between the EAP server and an
>    EAP peer.  The document defines a key distribution exchange (KDE)
>    protocol that can distribute these different types of root keys over
>    AAA and discusses its security requirements.
>
>Working Group Summary
>    The hokey WG has reviewed the document without particular controversy.
>
>Document Quality
>    The document is of high quality and well written.