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ABFAB                                                         J. Howlett
Internet-Draft                                                 JANET(UK)
Intended status: Informational                                S. Hartman
Expires: May 3, 2012                                   Painless Security
                                                        October 31, 2011


           A RADIUS Attribute, Binding and Profiles for SAML
                      draft-ietf-abfab-aaa-saml-02

Abstract

   This document specifies a RADIUS attribute, binding and two profiles
   for the Security Assertion Mark-up Language (SAML).  The attribute
   provides RADIUS encapsulation of SAML protocol messages, while the
   binding describes the transport of this attribute, and the SAML
   protocol messages within, using RADIUS.  The profiles describe the
   application of this binding for Abfab authentication and assertion
   query/request.  The SAML RADIUS attribute and binding are defined
   generically to permit application in other scenarios, such as network
   access.

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
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 3, 2012.

Copyright Notice

   Copyright (c) 2011 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
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents



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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  RADIUS SAML-Message Attribute  . . . . . . . . . . . . . . . .  4
   4.  SAML RADIUS Binding  . . . . . . . . . . . . . . . . . . . . .  5
     4.1.  Required Information . . . . . . . . . . . . . . . . . . .  5
     4.2.  Operation  . . . . . . . . . . . . . . . . . . . . . . . .  5
       4.2.1.  Metadata Considerations  . . . . . . . . . . . . . . .  6
   5.  Abfab Authentication Profile . . . . . . . . . . . . . . . . .  6
     5.1.  Required Information . . . . . . . . . . . . . . . . . . .  6
     5.2.  Profile Overview . . . . . . . . . . . . . . . . . . . . .  7
     5.3.  Profile Description  . . . . . . . . . . . . . . . . . . .  9
       5.3.1.  User Agent Request to Relying Party  . . . . . . . . .  9
       5.3.2.  Relying Party Issues <samlp:AuthnRequest> to
               Identity Provider  . . . . . . . . . . . . . . . . . .  9
       5.3.3.  Identity Provider Identifies Principal . . . . . . . .  9
       5.3.4.  Identity Provider Issues <samlp:Response> to
               Relying Party  . . . . . . . . . . . . . . . . . . . . 10
       5.3.5.  Relying Party Grants or Denies Access to Principal . . 10
     5.4.  Use of Authentication Request Protocol . . . . . . . . . . 10
       5.4.1.  <samlp:AuthnRequest> Usage . . . . . . . . . . . . . . 10
       5.4.2.  <samlp:Response message> Usage . . . . . . . . . . . . 11
       5.4.3.  samlp:Response Message Processing Rules  . . . . . . . 12
       5.4.4.  Unsolicited Responses  . . . . . . . . . . . . . . . . 12
       5.4.5.  Use of the SAML RADIUS Binding . . . . . . . . . . . . 12
       5.4.6.  Metadata Considerations  . . . . . . . . . . . . . . . 12
   6.  Abfab Assertion Query/Request Profile  . . . . . . . . . . . . 12
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 13
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 13
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 13
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 14












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1.  Introduction

   The SAML RADIUS attribute, binding and profiles are motivated by the
   requirements of the Abfab architecture [I-D.lear-abfab-arch].  In
   this architecture, it is often desirable to convey Security Assertion
   Mark-up Language (SAML) protocol messages between a SAML requester
   and SAML responder; for example, to allow a Relying Party to obtain a
   SAML assertion containing attributes that describe a principal.

   SAML [OASIS.saml-core-2.0-os] defines a number of SAML protocol
   messages that are used for a range of different purposes
   [OASIS.saml-profiles-2.0-os].  These messages are derived from common
   request and reponse abstract types.  These request and response
   protocol messages can be exchanged using a variety of underlying
   transport protocols, such as HTTP.  In the SAML model, the means by
   which a SAML protocol message exchange is framed over an underlying
   transport protocol is known as a SAML 'binding'.  SAML already
   defines [OASIS.saml-bindings-2.0-os] a number of mainly HTTP-based
   bindings; these principally use HTTP as the underlying transport
   protocol, generally for use with the SAML Web Browser Single Sign-On
   Profile [OASIS.saml-profiles-2.0-os].

   However, the goal of Abfab is to extend the applicability of
   federated identity beyond the Web to other application protocols by
   building on the AAA framework.  Consequently here exists a
   requirement for an AAA-based binding, that is functionally equivalent
   to the existing bindings, that uses the RADIUS [RFC2865] and Diameter
   [RFC3588] protocols, rather than HTTP.  This document defines a new
   RADIUS-based SAML binding, building on a SAML RADIUS attribute also
   defined by this document.

   This attribute and binding are likely to be useful for purposes
   besides Abfab; an example of one potential application is SAML-based
   authorisation for network access.  The attribute and binding are
   therefore defined generically to facilitate general applicability.
   Nonetheless it is useful to also define how the SAML RADIUS binding
   should be used for Abfab-specific purposes to facilitate
   interoperability.  This document therefore also define two profiles
   of this binding to support authentication and assertion request.

   To summarise, this document specifies:

   o  A SAML RADIUS attribute that defines how to encapsulate a SAML
      protocol message within a RADIUS attribute.

   o  A SAML RADIUS binding that defines how SAML requesters and
      responders can exchange SAML protocol messages.




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   o  The Abfab Authentication Profile that defines how the SAML RADIUS
      binding is used to effect SAML-based authentication and
      authorisation within the Abfab architecture.

   o  The Abfab Assertion Request Profile that defines how the SAML
      RADIUS binding is used to effect SAML-based assertion request
      within the Abfab architecture.

   The RADIUS SAML binding and profile specifications aspire to adhere
   to the guidelines stipulated by [OASIS.saml-bindings-2.0-os] and
   [OASIS.saml-profiles-2.0-os] respectively.  To this end, the binding
   and profiles provide a 'Required Information' section that
   enumerates:

   o  A URI that uniquely identifies the protocol binding or profile

   o  Postal or electronic contact information for the author

   o  A reference to previously defined bindings or profiles that the
      new binding updates or obsoletes.

   o  In the case of a profile, any SAML confirmation method identifiers
      defined and/or utilized by the profile.

2.  Conventions

   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 RFC 2119 [RFC2119].

3.  RADIUS SAML-Message Attribute

   This attribute contains a SAML [OASIS.saml-core-2.0-os] protocol
   message.  Where multiple SAML-Message attributes are included in a
   RADIUS message, the Message fields of these attributes are to be
   concatenated to form a single SAML message.

   A summary of the SAML-Message format is shown below.  The fields are
   transmitted from left to right.

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Type      |    Length     |         SAML Message...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                                    Figure 1




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   Type:  TBD

   Length:  >=4

   Message:  The Message field is one or more octets containing a SAML
      message.  If larger than a single attribute, the SAML message data
      MUST be split on 253-octet boundaries over as many attributes as
      necessary.  The SAML message is reconstructed by concatenating the
      contents of all SAML-Message attributes.

   TODO: request a new RADIUS attribute

4.  SAML RADIUS Binding

   The SAML RADIUS binding defines how RADIUS [RFC2865] can be used to
   enable a RADIUS client and server to exchange SAML protocol messages.

4.1.  Required Information

   Identification: TBD

   Contact information: TBD

   Updates: None.

4.2.  Operation

   RADIUS can be used over multiple underlying transports; this binding
   calls out the use of RADIUS over UDP as REQUIRED.  It is RECOMMENDED
   that the RADIUS exchange is protected using TLS encryption for RADIUS
   [I-D.ietf-radext-radsec] to provide confidentiality and improve
   integrity protection.

   The system model used for SAML conversations over RADIUS is a simple
   request-response model, using the RADIUS SAML-Message attribute
   defined in Section 3 to encapsulate the SAML protocol messages.

   1.  The RADIUS client, acting as a SAML requester, transmits a SAML
       request element within a RADIUS Access-Request message.  This
       message MUST include a single instance of the RADIUS User-Name
       attribute whose value MUST conform to the Network Access
       Identifier [RFC4282] scheme.  The NAI SHOULD be used to route the
       message towards the SAML responder, which MAY be more than one
       RADIUS hop distant.  The SAML requester MUST NOT include more
       than one SAML request element.

   2.  The RADIUS server, acting as a SAML responder, MAY return a SAML
       protocol message within a RADIUS Access-Accept or Access-Reject



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       message.  The SAML responder MUST NOT include more than one SAML
       response.  A SAML responder that refuses to perform a message
       exchange with the SAML requester MUST silently discard the SAML
       request.

   A SAML responder MAY also return an unsolicited responser (a SAML
   response generated and emitted in the absence of a request from a
   SAML requester).

   This binding is intended to be composed with any use of RADIUS, such
   as network access.  Therefore, other arbitrary RADIUS attributes MAY
   be used in either the request of response.

   In the case of a SAML processing error and successful authentication,
   the RADIUS server SHOULD include a SAML-specified <samlp:Status>
   element in the SAML response that is transported within the Access-
   Accept packet sent by the RADIUS server.

   In the case of a SAML processing error and failed authentication, the
   RADIUS server MAY include a SAML-specified <samlp:Status> element in
   the SAML response that is transported within the Access-Reject packet
   sent by the RADIUS server.

4.2.1.  Metadata Considerations

   There are no metadata considerations particular to this binding.

5.  Abfab Authentication Profile

   In the scenario supported by the Abfab Authentication Profile, a
   Principal controlling a User Agent requests access to a Relying
   Party.  The User Agent and Relying Party use the GSS EAP mechanism to
   authenticate the Principal.  The Relying Party, acting as an EAP
   pass-through authenticator, acts as a conduit for the EAP frames
   emitted by the User Agent and an EAP server which acts as the
   Principal's Identity Provider.  If the Identity Provider successfully
   authenticates the Principal, it produces an authentication assertion
   which is consumed by the Relying Party.  During this process, a name
   identifier might also be established between the Relying Party and
   the Identity Provider.

5.1.  Required Information

   Identification: TBD

   Contact information: TBD

   SAML Confirmation Method Identifiers: The SAML V2.0 "sender vouches"



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   confirmation method identifier,
   urn:oasis:names:tc:SAML:2.0:cm:sender-vouches, is used by this
   profile.

   Updates: None.

5.2.  Profile Overview

   To implement this scenario, a profile of the SAML Authentication
   Request protocol is used in conjuction with the SAML RADIUS binding
   defined in Section 4 and the GSS EAP mechanism
   [I-D.ietf-abfab-gss-eap].

   This profile is based on the SAML Web Browser Single Sign-On Profile
   [OASIS.saml-profiles-2.0-os].  There are some important differences
   between these profiles; specifically:

   o  Authentication.  This profile specifically calls out the use of a
      particular authentication framework (although not a particular
      authentication mechanism).  This is necessary so that the profile
      is able to build on the AAA and GSS frameworks.

   o  Bindings.  This profile does not use any HTTP-based bindings;
      instead, all SAML protocol messages are transported using the SAML
      RADIUS binding defined in Section 4.  This is intended to minimize
      the number of bindings that interoperable implementations must
      support.

   o  Signatures.  This profile prohibits the use of digital signatures
      in SAML elements.  This includes signatures in the <samlp:
      AuthnRequest>, <samlp:Response> and <saml:Assertion> elements.
      Message source authentication and integrity are provided by the
      binding's transport.  This is intended to simplify the trust model
      and reduce the size of the SAML payloads.

   o  Requests.  The profile does not permit the Relying Party to name
      the <saml:Subject> of the <samlp:AuthnRequest>.  This is intended
      to simplify the business logic of interoperable implementations.

   o  Responses.  The profile only permits the Identity Provider to
      return a single assertion that must contain exactly one
      authentication statement.  Other statements may be included within
      this assertion at the disgression of the Identity Provider.  This
      is intended to simplify the business logic of interoperable
      implementations.






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   Figure 1 below illustrates the flow of messages within this profile.

     User Agent          Relying Party             Identity Provider
         |                     |                           |
         |         (1)         |                           |
         | - - - - - - - - - > |                           |
         |                     |                           |
         |                     |            (2)            |
         |                     | - - - - - - - - - - - - > |
         |                     |                           |
         |              (3)    |                           |
         | < - - - - - - - - - |- - - - - - - - - - - - -> |
         |                     |                           |
         |                     |            (4)            |
         |                     | < - - - - - - - - - - - - |
         |                     |                           |
         |         (5)         |                           |
         | < - - - - - - - - - |                           |
         |                     |                           |
         V                     V                           V

   The following steps are described by the profile.  Within an
   individual step, there may be one or more actual message exchanges.

                                 Figure 1

   1.  User Agent Request to Relying Party (Section 5.3.1): In step 1,
       the Principal, via a User Agent, makes a request for a secured
       resource at the Relying Party.  The Relying Party determines that
       no security context for the User Agent exists and initiates GSS
       EAP authentication of the Principal.

   2.  Relying Party Issues <samlp:AuthnRequest> to Identity Provider
       (Section 5.3.2).  In step 2, the Relying Party issues a <samlp:
       AuthnRequest> message to be delivered to the Identity Provider
       using the SAML RADIUS binding.

   3.  Identity Provider Identifies Principal (Section 5.3.3).  In step
       3, the Principal is identified by the Identity Provider using EAP
       authentication, while honoring any requirements imposed by the
       Relying Party in the <samlp:AuthnRequest> message.

   4.  Identity Provider Issues <samlp:Response> to Relying Party
       (Section 5.3.4).  In step 4, the Identity Provider issues a
       <samlp:Response> message to the Relying Party using the SAML
       RADIUS binding.  The response either indicates an error or
       includes an authentication statement in exactly one assertion.




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   5.  Relying Party Grants or Denies Access to Principal
       (Section 5.3.5).  In step 5, having received the response from
       the Identity Provider, the Relying Party can respond to the
       Principal's User Agent with its own error, or can establish its
       own security context for the Principal and return the requested
       resource.

   Note that an Identity Provider can initiate this profile at step 4
   and issue a <samlp:Response> message to a Relying Party without the
   preceding steps.

5.3.  Profile Description

   The Abfab Authentication Profile is a profile of the SAML V2.0
   Authentication Request Protocol [OASIS.saml-core-2.0-os].  Where this
   specification conflicts with Core, the former takes precedence.

   If the profile is initiated by the Relying Party, start with
   Section 5.3.1.  If initiated by the Identity Provider, start with
   Section 5.3.4.

5.3.1.  User Agent Request to Relying Party

   The profile is initiated by an arbitrary User Agent request to the
   Relying Party.  There are no restrictions on the form of the request.
   The Relying Party is free to use any means it wishes to associate the
   subsequent interactions with the original request.  The Relying
   Party, acting as a GSS acceptor, MUST invoke the GSS EAP mechanism
   (either spontaneously or as the result of a mechanism negotiation)
   and send an EAP-Identity/Request message to the User Agent, acting as
   a GSS initiator.

5.3.2.  Relying Party Issues <samlp:AuthnRequest> to Identity Provider

   The Relying Party, on receiving the EAP-Response/Identity message
   from the User Agent, MUST send it towards the Identity Provider using
   the SAML RADIUS binding.  The Relying Party MAY include a <samlp:
   AuthnRequest> within this RADIUS Access-Request message.  The next
   hop destination MAY be the Identity Provider or alternatively an
   intermediate RADIUS proxy.

   Profile-specific rules for the contents of the <samlp:AuthnRequest>
   element are given in Section 5.4.1.

5.3.3.  Identity Provider Identifies Principal

   The Identity Provider MUST establish the identity of the Principal
   using EAP authentication, or else it will return an error.  If the



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   ForceAuthn attribute on the <samlp:AuthnRequest> element is present
   and true, the Identity Provider MUST freshly establish this identity
   rather than relying on any existing session state it may have with
   the Principal (for example, TLS state that may be used for session
   resumption).  Otherwise, and in all other respects, the Identity
   Provider may use any EAP method to authenticate the Principal,
   subject to the requirements of Section 5.8 of
   [I-D.ietf-abfab-gss-eap]. and any others called out in the <samlp:
   AuthnRequest> message.

5.3.4.  Identity Provider Issues <samlp:Response> to Relying Party

   Regardless of the success or failure of the <samlp:AuthnRequest>, the
   Identity Provider MUST produce a <samlp:Response> message to be
   delivered to the Relying Party using the SAML RADIUS binding.

   Profile-specific rules regarding the contents of the <samlp:Response>
   element are given in Section 5.4.2.

5.3.5.  Relying Party Grants or Denies Access to Principal

   The Relying Party MUST process the <samlp:Response> message and any
   enclosed <saml:Assertion> elements as described in
   [OASIS.saml-core-2.0-os].  Any subsequent use of the <saml:Assertion>
   elements is at the discretion of the Relying Party, subject to any
   restrictions on use contained within the assertions themselves or
   previously established out-of-band policy governing interactions
   between the Identity Provider and the Relying Party.

   To complete the profile, the Relying Party creates a GSS security
   context for the User Agent.

5.4.  Use of Authentication Request Protocol

   This profile is based on the Authentication Request Protocol defined
   in [OASIS.saml-core-2.0-os].  In the nomenclature of actors
   enumerated in section 3.4, the Relying Party is the requester, the
   User Agent is the attesting entity and the Principal is the Requested
   Subject.

5.4.1.  <samlp:AuthnRequest> Usage

   A Relying Party MAY include any message content described in
   [OASIS.saml-core-2.0-os], Section 3.4.1.  All processing rules are as
   defined in [OASIS.saml-core-2.0-os].

   If the Identity Provider cannot or will not satisfy the request, it
   MUST respond with a <samlp:Response> message containing an



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   appropriate error status code or codes.

   If the Relying Provider wishes to permit the Identity Provider to
   establish a new identifier for the principal if none exists, it MUST
   include a <saml:NameIDPolicy> element with the AllowCreate attribute
   set to "true".  Otherwise, only a principal for whom the Identity
   Provider has previously established an identifier usable by the
   Relying Party can be authenticated successfully.

   The Relying Party MUST NOT include a <saml:Subject> element in the
   request.  The authenticated EAP Identity implicitly names the
   Principal of the requested <samlp:AuthnRequest> to the Identity
   Provider.

   The <samlp:AuthnRequest> message MUST NOT be signed.  Authentication
   and integrity are provided by the RADIUS SAML binding.

5.4.2.  <samlp:Response message> Usage

   If the Identity Provider wishes to return an error, it MUST NOT
   include any assertions in the <samlp:Response message>.  Otherwise,
   if the request is successful (or if the response is not associated
   with a request), the <samlp:Response> element MUST conform to the
   following:

   o  It MUST NOT be signed.

   o  It MUST contain exactly one <saml:Assertion>.  The <saml:Subject>
      element of this assertion MUST refer to the authenticated
      Principal.

   o  The assertion MUST contain a <saml:AuthnStatement>.  This MUST
      contain a <saml:Subject> element with at least one <saml:
      SubjectConfirmation> element containing a Method of
      urn:oasis:names:tc:SAML:2.0:cm:sender-vouches that reflects the
      authentication of the Principal to the Identity Provider.  If the
      containing message is in response to an <samlp:AuthnRequest>, then
      the InResponseTo attribute MUST match the request's ID.

   o  Other statements and confirmation methods MAY be included in the
      assertion at the discretion of the Identity Provider.  In
      particular, <samlp:AttributeStatement> elements MAY be included.
      Deployers should be aware of the implications of allowing weaker
      confirmation as the processing as defined in section 2.4.1.1 of
      [OASIS.saml-core-2.0-os] is effectively satisfy-any.

   o  Other conditions MAY be included as requested by the Relying Party
      or at the discretion of the Identity Provider.  The Identity



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      Provider is NOT obligated to honor the requested set of in the
      <samlp:AuthnRequest>, if any.

5.4.3.  samlp:Response Message Processing Rules

   The Relying Party MUST do the following:

   o  Verify that the InResponseTo attribute in the bearer <saml:
      SubjectConfirmationData> equals the ID of its original <samlp:
      AuthnRequest> message, unless the response is unsolicited, in
      which case the attribute MUST NOT be present.

   o  If a <saml:AuthnStatement> used to establish a security context
      for the Principal contains a SessionNotOnOrAfter attribute, the
      security context SHOULD be discarded once this time is reached,
      unless the service provider reestablishes the Principal's identity
      by repeating the use of this profile.

   o  Verify that any assertions relied upon are valid according to
      processing rules in [OASIS.saml-core-2.0-os].

   o  Any assertion which is not valid, or whose subject confirmation
      requirements cannot be met MUST be discarded and MUST NOT be used
      to establish a security context for the Principal.

5.4.4.  Unsolicited Responses

   An Identity Provider MAY initiate this profile by delivering an
   unsolicited <samlp:Response> message to a Relying Party.

   An unsolicited <samlp:Response> MUST NOT contain an InResponseTo
   attribute, nor should any sender-vouches <saml:
   SubjectConfirmationData> elements contain one.

5.4.5.  Use of the SAML RADIUS Binding

   It is RECOMMENDED that the RADIUS exchange is protected using TLS
   encryption for RADIUS [I-D.ietf-radext-radsec] to provide
   confidentiality and improve integrity protection.

5.4.6.  Metadata Considerations

   There are no metadata considerations particular to this binding.

6.  Abfab Assertion Query/Request Profile






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7.  Security Considerations

   TODO

8.  IANA Considerations

   Assignments of additional enumerated values for the RADIUS attributes
   defined in this document are to be processed as described in
   [RFC3575], subject to the additional requirements of a published
   specification.

9.  References

9.1.  Normative References

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

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

   [OASIS.saml-core-2.0-os]      Cantor, S., Kemp, J., Philpott, R., and
                                 E. Maler, "Assertions and Protocol for
                                 the OASIS Security Assertion Markup
                                 Language (SAML) V2.0", OASIS
                                 Standard saml-core-2.0-os, March 2005.

   [RFC3575]                     Aboba, B., "IANA Considerations for
                                 RADIUS (Remote Authentication Dial In
                                 User Service)", RFC 3575, July 2003.

   [RFC4282]                     Aboba, B., Beadles, M., Arkko, J., and
                                 P. Eronen, "The Network Access
                                 Identifier", RFC 4282, December 2005.

   [I-D.ietf-radext-radsec]      Winter, S., McCauley, M., Venaas, S.,
                                 and K. Wierenga, "TLS encryption for
                                 RADIUS", draft-ietf-radext-radsec-09
                                 (work in progress), July 2011.

   [I-D.ietf-abfab-gss-eap]      Hartman, S. and J. Howlett, "A GSS-API
                                 Mechanism for the Extensible
                                 Authentication Protocol",
                                 draft-ietf-abfab-gss-eap-04 (work in
                                 progress), October 2011.



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Internet-Draft                 SAML RADIUS                  October 2011


9.2.  Informative References

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

   [I-D.lear-abfab-arch]         Howlett, J., Hartman, S., Tschofenig,
                                 H., and E. Lear, "Application Bridging
                                 for Federated Access Beyond Web (ABFAB)
                                 Architecture", draft-lear-abfab-arch-02
                                 (work in progress), March 2011.

   [OASIS.saml-bindings-2.0-os]  Cantor, S., Hirsch, F., Kemp, J.,
                                 Philpott, R., and E. Maler, "Bindings
                                 for the OASIS Security Assertion Markup
                                 Language (SAML) V2.0", OASIS
                                 Standard saml-bindings-2.0-os,
                                 March 2005.

   [OASIS.saml-profiles-2.0-os]  Hughes, J., Cantor, S., Hodges, J.,
                                 Hirsch, F., Mishra, P., Philpott, R.,
                                 and E. Maler, "Profiles for the OASIS
                                 Security Assertion Markup Language
                                 (SAML) V2.0", OASIS
                                 Standard OASIS.saml-profiles-2.0-os,
                                 March 2005.

Authors' Addresses

   Josh Howlett
   JANET(UK)
   Lumen House, Library Avenue, Harwell
   Oxford  OX11 0SG
   UK

   Phone: +44 1235 822363
   EMail: Josh.Howlett@ja.net


   Sam Hartman
   Painless Security


   Phone:
   EMail: hartmans-ietf@mit.edu






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