Requirements and Analysis of Media Security Management Protocols
draft-ietf-sip-media-security-requirements-09

[Ballot comment]
In my opinion, readability would be enhanced if forward references to requirements
included section numbers.

For example, in Section 3:

OLD

  The discussion in this section relates to requirements R-PASS-MEDIA,
  R-PASS-SIG, R-ASSOC, R-SIG-MEDIA, R-ACT-ACT, and R-ID-BINDING.

NEW

  The discussion in this section relates to requirements R-ASSOC (specified in
  Section 5.1), R-PASS-MEDIA,  R-PASS-SIG, R-SIG-MEDIA, R-ACT-ACT, and
  R-ID-BINDING (specified in Section 5.2).

This could alternatively be addressed in the Introduction, noting that that requirements
have the form R-xxxx and are specified after the motivating text, or by adding section
numbers to the definitions (e.g., the definiton of R-PASS-MEDIA would refer to section 3).

[Ballot comment]
(Oops -- wrong document, please ignore the "discuss" text)

Tero Kivinen's SecDir review identified some parts that would
benefit from editorial improvements (such as giving pointers
to specific sections of 5.* when discussing R-* in Sections 3 and 4).

http://www.ietf.org/mail-archive/web/secdir/current/msg00171.html

[Ballot discuss]
The document needs some more text about how the responder's
fingerprint is protected. In other words, how exactly the UPDATE
messages and associated offer/answer works together with RFC 4474
and 4916 (the UPDATE message examples in RFC 4916 have an empty
message body, and thus wouldn't protect the fingerprint).
Adding a second example to Section 7, showing UPDATE and RFC 4916
would make this much clearer.

[Ballot comment]
Tero Kivinen's SecDir review identified some parts that would
benefit from editorial improvements (such as giving pointers
to specific sections of 5.* when discussing R-* in Sections 3 and 4).

http://www.ietf.org/mail-archive/web/secdir/current/msg00171.html

[Ballot discuss]
The Gen-ART Review by Elwyn Davies on 10-Oct-2008 has not been
  addressed.  Elwyn ashed some questions, and I have not seen a
  response that offers answers to the questions.

  The Gen-ART Review by Elwyn Davies can be found at:
    http://www.softarmor.com/rai/temp-gen-art/
    draft-ietf-sip-media-security-requirements-07-davies.txt

  The questions from the review are:

  Section 5.1, Requirement R-NEGOTIATE: Does this imply that the
  protocol MAY allow the SIP UA to use the same parameters for
  several sessiosn if it wants to?

  Section 5.2, Requirement R-FIPS: Are there other similar requirements
  from other countries that ought to be considered?

  Section 5.2, Requirement R-DOS: Whilst I know that it is probably
  impossible to guarantee that a given solution will not introduce
  some arcane DOS opportunity that no one has thought of, it seems to
  me that 'MUST NOT introduce any foreseeable (or, maybe, significant)
  new DoS vulnerabilities' would be better than SHOULD NOT, which
  allows for possible weaseling.

(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?

The Document Shepherd is SIP WG chair Dean Willis, who has reviewed
the document and believes it is ready for publication.

(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?

The document has been adequate reviewed inside the WG, and
additionally reviewed by OMA. The shepherd has no concerns about the
reviews.

(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.

The shepherd is aware of no relevant issues.

(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?

Working group consensus on this document is very strong.

(1.f) Has anyone threatened an appeal or otherwise indicated
extreme discontent? If so, please summarize 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.)

The shepherd is unaware of any reservoir of extreme discontent related
to this draft.

(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? If the
document does not already indicate its intended status at
the top of the first page, please indicate the intended
status here.

The document reasonably passes all nit checks, with the exception of
several out-of-date references that do not impact the specification.

(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].

References are appropriately divided. All normative references are to
stable documents.

(1.i) Has the Document Shepherd verified that the document's IANA
Considerations 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 [RFC2434]. If the
document describes an Expert Review process, has the Document
Shepherd conferred with the Responsible Area Director so that
the IESG can appoint the needed Expert during IESG
Evaluation?

The document contains no IANA actions and specified no revew process.

(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?

The document contains no formal language.

(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

This document describes requirements for a protocol to negotiate a
security context for SIP-signaled SRTP media. In addition to the
natural security requirements, this negotiation protocol must
interoperate well with SIP in certain ways. A number of proposals
have been published and a summary of these proposals is in the
appendix of this document.

Working Group Summary

There was considerable controvery about the inclusion of requirements
related to key disclosure. The 3GPP community wished to include a
requirement that arguably enabled MITM attacks -- essentially
requiring that the media key always be disclosed to signaling path
elements, such that lawful intercept can be exceuted without the
awareness of the endpoints. This requirement was excluded from the
final version of the document.

Document Quality

Security adviser Eric Rescorla was actively involved in reviewing the
requirements, as they apply to the SRTP/DTLS framework for which he is
the editor.

Personnel

The Document Shepherd is Dean Willis. The Responsible Area Director is
Cullen Jennings. No IANA experts are required.