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Last Call Review of draft-johansson-loa-registry-

Request Review of draft-johansson-loa-registry
Requested revision No specific revision (document currently at 06)
Type Last Call Review
Team General Area Review Team (Gen-ART) (genart)
Deadline 2012-04-10
Requested 2012-03-29
Authors Leif Johansson
I-D last updated 2012-05-01
Completed reviews Genart Last Call review of -?? by David L. Black
Genart Last Call review of -?? by David L. Black
Secdir Last Call review of -?? by Vincent Roca
Assignment Reviewer David L. Black
State Completed
Request Last Call review on draft-johansson-loa-registry by General Area Review Team (Gen-ART) Assigned
Completed 2012-05-01
The -05 version of this draft resolves all of the issues and comments raised
in the Gen-ART review of the -04 version.


> -----Original Message-----
> From: Black, David
> Sent: Sunday, April 01, 2012 4:57 PM
> To: leifj at; gen-art at; ietf at
> Cc: Black, David; Sean Turner; tim.polk at
> Subject: Gen-ART review of draft-johansson-loa-registry-04
> I am the assigned Gen-ART reviewer for this draft. For background on
> Gen-ART, please see the FAQ at
> <>.
> Please resolve these comments along with any other Last Call comments
> you may receive.
> Document: draft-johansson-loa-registry-04
> Reviewer: David L. Black
> Review Date: April 1, 2012
> IETF LC End Date: April 3, 2012
> IESG Telechat date: April 12, 2012
> This draft establishes an IETF registry of SAML Level of Assurance (LoA)
> profiles;
> it's short and clear, although it does not contain any initial content for the
> registry - presumably that will be supplied after the registry is created via
> the
> expert review registration mechanism established by this draft.
> Summary:
> This draft is on the right track but has open issues, described in the review.
> Major issues: (1)
> My major open issue concerns the last paragraph in the Introduction:
>    Although the registry will contain URIs that reference SAML
>    Authentication Context Profiles other protocols MAY use such URIs to
>    represent levels of assurance definitions without relying on their
>    SAML XML definitions.  Use of the registry by protocols other than
>    SAML or OpenID Connect is encouraged.
> While this is good in principle, and one presumes that each registration of
> sets of profiles from an existing protocol will be self-consistent, this
> text also encourages other (e.g., new) protocols to draw upon this registry
> without providing any guidance.  I'm concerned that it's probably possible
> to make a serious mess in a new protocol by using an LoA or two from multiple
> sets of registered LoAs without paying attention to whether the resulting
> collection of LoAs is consistent or coherent (or even sensible) for use in
> a single protocol.  This concern is reinforced by the guidance to expert
> reviewers in Section 4.1, which effectively conveys a desire to get all
> of the reasonable LoA profiles registered here, regardless of source or
> consistency with other registered LoA profiles.
> I'd like to see some guidance to protocol designers and others for how to
> appropriately select multiple LoA profiles from this registry in a fashion
> that results in a consistent and (hopefully) usable collection.  For example,
> it may be a good idea to use (or start with) a set of related profiles already
> in use by an existing protocol in preference to mixing/matching individual
> profiles from multiple existing protocols.  At some level, this is common
> sense advice that the presence of profiles in this registry does not obviate
> the need to apply good design judgment, but that does deserve to be stated.
> Minor issues: (2)
> (1) This draft is intended to be an informational RFC, but it uses
> RFC 2119 keywords.  That's only a good idea in exceptional circumstances. I
> suggest removing section 1.1 and replacing upper case MUST/SHOULD/MAY with
> their lower case versions or reworded explanations of rationale.  Most of
> the uses of RFC 2119 keywords are not protocol requirements, but requirements
> on IANA, registrants, and users of the registry for which RFC 2119 keywords
> are not appropriate, e.g., see RFC 2119 section 6:
>    Imperatives of the type defined in this memo must be used with care
>    and sparingly.  In particular, they MUST only be used where it is
>    actually required for interoperation or to limit behavior which has
>    potential for causing harm (e.g., limiting retransmisssions)
> (2) Section 4
>    The initial pool of expert and the
>    review criteria are outlined below.
>    The review criteria are outlined below.
> The initial pool of experts is not designated by this draft.
> Nits/editorial comments:
> Section 3
>    The following ABNF productions represent reserved values and names
>    The reserved element defined by the following ABNF productions represents
>    a set of reserved values and names
> Section 4
>    The registry is to be operated under the "Designated Expert Review"
>    policy from RFC5226 [RFC5226] employing a pool of experts
> Nope, the actual RFC5226 name of that well-known IANA policy is Expert
> Review (or Designated Expert), see section 4.1 of RFC5226.  If that
> well-known IANA policy isn't what was intended, this is a serious
> open issue.
> Top of p.7
>    The presense of an entry in the registy MUST NOT be taken to imply
>                                          ^
> r ---------------------------------------/
> Section 7
>    An implementor of MUST NOT treat the registry as a trust framework or
>    A protocol implementor MUST NOT treat the registry as a trust framework or
> The minor issue about RFC 2119 keywords also applies to this text.
> idnits 2.12.13 did not find any nits that need attention.
> Thanks,
> --David
> ----------------------------------------------------
> David L. Black, Distinguished Engineer
> EMC Corporation, 176 South St., Hopkinton, MA  01748
> +1 (508) 293-7953             FAX: +1 (508) 293-7786
> at        Mobile: +1 (978) 394-7754
> ----------------------------------------------------