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Versions: 00 01 02 03 04 05 06 rfc6711                     Informational
Network Working Group                                       L. Johansson
Internet-Draft                                                  NORDUNet
Intended status: Informational                         February 18, 2012
Expires: August 21, 2012


         An IANA registry for Level of Assurance (LoA) Profiles
                    draft-johansson-loa-registry-04

Abstract

   This document establishes an IANA registry for Level of Assurance
   (LoA) Profiles.  The registry is intended to be used as an aid to
   discovering such LoA definitions in protocols that use an LoA
   concept, including SAML 2.0 and OpenID Connect.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on August 21, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   described in the Simplified BSD License.




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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . . . 3
   2.  Name of Registry  . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Registration Template . . . . . . . . . . . . . . . . . . . . . 4
     3.1.  Example Registration  . . . . . . . . . . . . . . . . . . . 5
     3.2.  Note on the Example . . . . . . . . . . . . . . . . . . . . 6
   4.  Registration Policy . . . . . . . . . . . . . . . . . . . . . . 6
     4.1.  Reviewer Expectations . . . . . . . . . . . . . . . . . . . 6
   5.  Registry Semantics  . . . . . . . . . . . . . . . . . . . . . . 6
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
   7.  Security Considerations . . . . . . . . . . . . . . . . . . . . 7
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 7
   9.  Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     9.1.  since -00 . . . . . . . . . . . . . . . . . . . . . . . . . 7
     9.2.  since -01 . . . . . . . . . . . . . . . . . . . . . . . . . 8
     9.3.  since -02 . . . . . . . . . . . . . . . . . . . . . . . . . 8
     9.4.  since -03 . . . . . . . . . . . . . . . . . . . . . . . . . 8
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     10.1. Normative References  . . . . . . . . . . . . . . . . . . . 8
     10.2. Informative References  . . . . . . . . . . . . . . . . . . 8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 9




























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1.  Introduction

   This document establishes an IANA registry for Level of Assurance
   Profiles.  One definition of a 'level of assurance' is given in
   RFC4949 [RFC4949] which also identifies the roots of such profiles in
   the NIST special publication series, in particular SP 800-63 [SP63].
   Such profiles are used in various protocols, including SAML 2.0 and
   OpenID Connect.  For SAML 2.0 the registry entries reference XML
   schema definitions that fulfil the requirements of sstc.saml-
   assurance-profile [OASIS.sstc.saml-assurance-profile].  For OpenID
   Connect the registry consists a controlled vocabulary for the
   iso29115level claim type.  Quoting from sstc.saml-assurance-profile
   [OASIS.sstc.saml-assurance-profile] we find the following definition
   of the concept of level of assurance:

   _Many existing (and potential) SAML federation deployments have
   adopted a "levels of assurance" (or LOA) model for categorizing the
   wide variety of authentication methods into a small number of levels,
   typically based on some notion of the strength of the authentication.
   Federation members (service providers or "relying parties") then
   decide which level of assurance is required to access specific
   protected resources, based on some assessment of "value" or "risk"._

   Several so called trust frameworks and identity federations now
   exist, some of which define one or more Level of Assurance (LoA).
   The purpose of this specification is to create an IANA registry where
   such LoA definitions can be discovered.  While the quote above
   references SAML explicitly the notion of a "level of assurance" has
   gained wide-spread acceptance and should be treated as a protocol-
   independent concept.  The proposed IANA registry attempts to reflects
   this.

   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.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].


2.  Name of Registry

   The name of the registry shall be "SAML 2.0 LoA Context Class", in



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   plural "SAML LoA Context Classes".  The term LoA is an abbreviation
   of Level of Assurance.


3.  Registration Template

   The following information MUST be provided with each registration:

   URI:  A URI referencing a Level of Assurance Profile This is the
      registry key.

   Context Class:  A valid XML schema definition for the SAML 2.0 LoA
      Context Class fulfilling the requirements of sstc.saml-assurance-
      profile [OASIS.sstc.saml-assurance-profile].  The registry key
      (the URI) is the unique identifier for the Context Class.

   Name:  A string uniquely identifying the LoA for use in protocols
      where URIs are not appropriate.

   Informational URL:  A URL containing auxilliary information.  This
      URL MUST minimally reference contact information for the
      administrative authority of the level of assurance definition.

   Note that it is not uncommon for a single XML Schema to contain
   definitions of multiple URIs.  In that case the registration MUST be
   repeated for each URI.  Both the name and the URI MUST uniquely
   identify the LoA.  The name is meant to be used in protocols where
   URIs are not appropriate.  In addition the requester is expected to
   provide basic contact information and the name of the organization on
   behalf of which the LoA definition is registered.

   The name MUST fulfill the following ABNF:
   label = ( ALPHA / DIGIT )
   name = label 1*( label / "-" / "." / "_" )

   The following ABNF productions represent reserved values and names
   matching any of these productions MUST NOT be present in any
   registration:
   reserved = loa / al / num
   loa = ( "l" / "L" ) ( "o" / "O" ) ( "a" / "A") *DIGIT
   al = ( "a" / "A") ( "l" / "L") *DIGIT
   num = *DIGIT
   The reason for excluding these productions is a desire to avoid a
   race to register overly generic LoA profiles under names like "AL1"
   or "LOA2".






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3.1.  Example Registration

   1.  Name of requester: J. Random User

   2.  E-mail address of requester: jrandom@example.com

   3.  Organization of requester: Random Trust Frameworks LLP

   4.  Requested registration:

   URI  http://foo.example.com/assurance/loa1

   Name  foo-loa-1

   SAML 2.0 Context Class Definition
 <?xml version="1.0" encoding="UTF-8"?>
 <xs:schema
     targetNamespace="http://foo.example.com/assurance/loa1"
     xmlns:xs="http://www.w3.org/2001/XMLSchema"
     xmlns="http://foo.example.com/assurance/loa1"
     finalDefault="extension"
     blockDefault="substitution"
     version="2.0">
   <xs:redefine
      schemaLocation="saml-schema-authn-context-loa-profile.xsd">
       <xs:annotation>
           <xs:documentation>
               Class identifier:
                   http://foo.example.com/assurance/loa1
                   Defines Level 1 of FAF
           </xs:documentation>
       </xs:annotation>
       <xs:complexType name="GoverningAgreementRefType">
         <xs:complexContent>
           <xs:restriction base="GoverningAgreementRefType">
             <xs:attribute name="governingAgreementRef"
               type="xs:anyURI"
               fixed="http://foo.example.com/foo_assurance.pdf#section1"
               use="required"/>
             </xs:restriction>
         </xs:complexContent>
       </xs:complexType>
   </xs:redefine>
 </xs:schema>







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3.2.  Note on the Example

   The example is borrowed from sstc.saml-assurance-profile
   [OASIS.sstc.saml-assurance-profile]


4.  Registration Policy

   The registry is to be operated under the "Designated Expert Review"
   policy from RFC5226 [RFC5226] employing a pool of experts.  IANA is
   kindly asked to do rough randomized load-balancing among the experts
   and also do an initial review of each submission to ensure that the
   name is unique within the registry.The initial pool of expert and the
   review criteria are outlined below.

   Registrations that reference multiple LoAs in a consistent set of
   policies - for instance when a trust framework defines multiple
   levels of assurance - the registered LoA Name and URIs SHOULD be
   consistently named so as to be easily identified as belonging to the
   same set of registrations.  For instance fruitLoA1,fruitLoA2 and
   fruitLoA3 is preferred over apple,pear and banana when these Names
   refer to a single set of policies defining 3 LoAs.

4.1.  Reviewer Expectations

   The expectation of the IANA LoA Registry is that it contain bona fide
   Level of Assurance Profiles while not presenting a very high bar for
   entry.  Expert reviewers SHOULD NOT place undue value in any
   percieved or actual quality of the associated trust framework or
   federation and SHOULD only exclude such registrations that in the
   view of the experts do not represent bona fide attempts at defining
   an LoA.

   The designated experts are also expected to verify that the
   registration is consistent and that the provided XML fulfills the
   requirements of sstc.saml-assurance-profile
   [OASIS.sstc.saml-assurance-profile].


5.  Registry Semantics

   The intended use for this registry is to serve as a basis for
   discovery of LoA definitions that might for instance be used by
   protocol-specific (eg SAML 2.0 or OpenID Connect) management tools.
   Consumers of the registry MUST NOT treat it as a complete list of all
   existing LoA definitions and MUST provide a way for the user to
   provide additional Level of Assurance Profile references by other
   means.  It is not expected that all LoA definitions will be contained



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   in this registry.

   The presense of an entry in the registy MUST NOT be taken to imply
   any semantics beyond the review done by the expert reviewers as part
   of the registration process.


6.  IANA Considerations

   This document sets up a registry with IANA making the whole document
   a set of considerations for IANA.


7.  Security Considerations

   An implementor of MUST NOT treat the registry as a trust framework or
   federation and MUST NOT make any assumptions about the properties of
   any of the listed level of assurance URIs or their associated trust
   frameworks or federations based on their presense in the IANA
   registry.


8.  Acknowledgements

   RL 'Bob' Morgan, Scott Cantor, Lucy Lynch and John Bradley were
   involved in the initial discussions around this idea and contributed
   to the semantics of the registry.  The various versions of the draft
   was socialized in the Kantara Federation Interoperability WG and in
   other parts of the identity community.


9.  Changes

   Note to the RFC editor: This section should be removed before
   publication.

9.1.  since -00

   o  Clarified the security considerations wrt the status of the IANA
      registry.

   o  Text in the introduction that explains that the registry can be
      used by other protocols than SAML and that this is encouraged.








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9.2.  since -01

   o  Allow for registration of short identifiers.

9.3.  since -02

   o  Make the text less explicitly dependent on SAML.

   o  Include OpenID Connect reference.

   o  Corrected the SSTC reference

   o  Reserve numeric-only LoA names (eg '1')

9.4.  since -03

   o  comments from PROTO writeup, AD and document shepherd

   o  remove initial list of reviewers - it will be decided by IESG

   o  example registration


10.  References

10.1.  Normative References

   [OASIS.sstc.saml-assurance-profile]
              Morgan, RL., Madsen, PM., and S. Cantor, "SAML V2.0
              Identity Assurance Profiles Version 1.0", November 2010.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

10.2.  Informative References

   [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
              RFC 4949, August 2007.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

   [SP63]     NIST, "Electronic Authentication Guideline, NIST Special
              Publication 800-63", June 2004.






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Author's Address

   Leif Johansson
   NORDUNet
   Tulegatan 11
   Stockholm
   Sweden

   Email: leifj@nordu.net










































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