One document matched: draft-ietf-abfab-aaa-saml-04.xml


<?xml version="1.0" encoding="US-ASCII"?>

<?rfc toc="yes"?>
<?rfc symrefs="yes"?>
<?rfc compact="yes"?>
<?rfc subcompact="no"?>
<?rfc strict="no"?>
<?rfc rfcedstyle="yes"?>
<?rfc comments="yes"?>
<?rfc inline="yes"?>

<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!ENTITY rfc2119 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml">
<!ENTITY rfc2865 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.2865.xml">
<!ENTITY rfc3575 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.3575.xml">
<!ENTITY rfc3579 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.3579.xml">
<!ENTITY rfc3588 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.3588.xml">
<!ENTITY rfc4282 SYSTEM "http://xml.resource.org/public/rfc/bibxml/reference.RFC.4282.xml">
<!ENTITY I-D.ietf-abfab-arch SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-ietf-abfab-arch-03.xml">
<!ENTITY I-D.ietf-abfab-gss-eap SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-ietf-abfab-gss-eap-04.xml">
<!ENTITY I-D.jones-diameter-abfab SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-jones-diameter-abfab-00.xml">
<!ENTITY I-D.draft-ietf-radext-radsec SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-ietf-radext-radsec-09.xml">
<!ENTITY I-D.draft-perez-radext-radius-fragmentation SYSTEM "http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-perez-radext-radius-fragmentation-01.xml">
<!ENTITY SAML2Core SYSTEM "http://xml.resource.org/public/rfc/bibxml2/reference.OASIS.saml-core-2.0-os.xml">
<!ENTITY SAML2Profiles SYSTEM "http://xml.resource.org/public/rfc/bibxml2/reference.OASIS.saml-profiles-2.0-os.xml">
<!ENTITY SAML2Bindings SYSTEM "http://xml.resource.org/public/rfc/bibxml2/reference.OASIS.saml-bindings-2.0-os.xml">
<!ENTITY SAML2Metadata SYSTEM "http://xml.resource.org/public/rfc/bibxml2/reference.OASIS.saml-metadata-2.0-os.xml">
]>

<rfc category="info" docName="draft-ietf-abfab-aaa-saml-04" ipr="trust200902">

    <front>
        <title abbrev="SAML RADIUS">A RADIUS Attribute, Binding and Profiles for SAML</title>
        <author initials="J." surname="Howlett" fullname="Josh Howlett">
          <organization>Janet</organization>
          <address>
            <postal>
              <street>Lumen House, Library Avenue, Harwell</street>
              <city>Oxford</city>
              <code>OX11 0SG</code>
              <country>UK</country>
            </postal>
            <phone>+44 1235 822363</phone>
            <email>Josh.Howlett@ja.net</email>
          </address>
        </author>
        <author initials="S." surname="Hartman" fullname="Sam Hartman">
          <organization>Painless Security</organization>
          <address>
            <postal>
              <street> </street>
              <city> </city>
              <code> </code>
              <country> </country>
            </postal>
            <phone> </phone>
            <email>hartmans-ietf@mit.edu</email>
          </address>
        </author>
        <date year="2012" />
        <area>Security Area</area>
        <workgroup>ABFAB</workgroup>
        <keyword>ABFAB</keyword>
        <keyword>AAA</keyword>
        <keyword>EAP</keyword>
        <keyword>GSS</keyword>
        <keyword>RADIUS</keyword>
        <keyword>SAML</keyword>
        <abstract>
            <t>
                This document specifies a RADIUS attribute, a binding and two profiles for the 
		Security Assertion Mark-up Language (SAML). The attribute provides RADIUS 
		encapsulation of SAML protocol messages, and the binding describes the use of
		this attribute, and the SAML protocol messages within, with RADIUS transport. 
		The two profiles describe the application of this binding for ABFAB 
		authentication and assertion query/request respectively. The SAML RADIUS 
		attribute and binding are defined generically to permit application in other 
		scenarios, such as network access.
            </t>
        </abstract>
    </front>

    <middle>
	<section title="TODO">
	    <list style="symbols">
		<t>
		    Clean up use of terminology (e.g., "principal") to ensure consistency with
		    other ABFAB docs.
		</t>
		<t>
		    Understand Alan DeK's preferences with respect to choreography of SAML
		    messages and the RADIUS exchange(s).
		</t>
		<t>
		    Request a new RADIUS attribute
		</t>
		<t>
		    Check that binding/profiles identification URNs are reasonable
		</t>
	    </list>
	</section>
        <section title="Introduction">
	    <t>
		The SAML RADIUS attribute, binding and profiles are motivated by the requirements 
		of the ABFAB architecture <xref target="I-D.ietf-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. This can be
		used, for example, to allow a Relying Party to request a SAML assertion from an 
		Identity Provider that describes a particular principal. This attribute and 
		binding are also likely to be useful for other purposes besides ABFAB; for 
		example, SAML-based authorization for network access. The attribute and binding
                are therefore defined generically to facilitate general applicability.
	    </t>
	    <t>
		SAML defines a number of SAML protocol messages
		<xref target="OASIS.saml-core-2.0-os" />, derived from common request and 
		response abstract types. These request and response protocol messages can be 
		exchanged using different modes of transport, such as HTTP; in the SAML 
		architecture, these are known as 'bindings'. SAML already 
		defines a number of HTTP-based bindings <xref target="OASIS.saml-bindings-2.0-os" />; 
		and these are primarily intended for use with the SAML V2.0 Web Browser 
		Single Sign-On Profile <xref target="OASIS.saml-profiles-2.0-os" /> which
		describes how the SAML protocol messages and HTTP-based bindings can be used
		to effect Web-based Single Sign-On (SSO) by federating an identity between 
		an Identity Provider and a Service Provider
	    </t>
	    <t>
		However the goal of ABFAB is to extend the applicability of federated identity 
		beyond the Web to other applications by building on the AAA framework. 
		Consequently there exists a requirement for an AAA-based binding that is 
		functionally equivalent to the existing bindings but using AAA protocols, such
		as <xref target="RFC2865"/> and Diameter <xref target="RFC3588"/>, rather than 
		HTTP. This document therefore defines a new RADIUS-based SAML binding, building 
		on a SAML RADIUS attribute also defined by this document, to meet this need.
	    </t>
	    <t>
		In addition to this attribute and binding, this document also profiles their 
		application in the context of two specific use cases: authentication and 
		assertion query/request. This is intended to promote interoperability between
		implementations for these common use cases.
	    </t>
	    <t>
		A companion specification <xref target="I-D.jones-diameter-abfab" /> specifies 
		equivalent funtionality for Diameter.
            </t>
	    <t>
		In summary this document specifies:
		<list style="symbols">
		    <t>
			A SAML RADIUS attribute that defines how to encapsulate a SAML protocol 
			message within a RADIUS attribute.
		    </t>
		    <t>
			A SAML RADIUS binding that defines how SAML requesters and responders can 
			exchange SAML protocol messages.
	    	    </t>
	    	    <t>
			An Authentication Profile that defines how the SAML RADIUS binding 
			is used to effect SAML-based authentication and authorization.
	    	    </t>
	    	    <t>
			An Assertion Query/Request Profile that defines how the SAML RADIUS 
			binding is used to effect SAML-based assertion request.
	    		</t>
		</list>
	    </t>
	    <t>
		The RADIUS SAML binding and profile specifications aspire to adhere to the 
		guidelines stipulated by <xref target="OASIS.saml-bindings-2.0-os" /> and 
		<xref target="OASIS.saml-profiles-2.0-os" /> for defining new SAML bindings
		and profiles respectively. These new bindings and profiles are asked to
		provide a 'Required Information' section that enumerates:
		<list style="symbols">
		    <t>
			A URI that uniquely identifies the protocol binding or profile
		    </t>
		    <t>
			Postal or electronic contact information for the author
		    </t>
		    <t>
			A reference to previously defined bindings or profiles that the new 
			binding updates or obsoletes
		    </t>
		    <t>
			In the case of a profile, any SAML confirmation method identifiers 
			defined and/or utilized by the profile
		    </t>
		</list>
	    </t>
        </section>

        <section title="Conventions">
            <t>
                 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 <xref target="RFC2119" />.
            </t>
        </section>
        
        <section title="RADIUS SAML-Message Attribute" anchor="SAML_RADIUS_Message_attribute">
            <t>
                This attribute contains a SAML <xref target="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.
            </t>
            <t>
                A summary of the SAML-Message format is shown below.  The fields are 
		transmitted from left to right.
            </t>
            <figure>
                <artwork><![CDATA[
 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
                ]]></artwork>
            </figure>
	    <list style="hanging">
		<t hangText="Type:">
			TBD
		</t>
		<t hangText="Length:">
			>=3
		</t>
		<t hangText="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.
                </t>
            </list>
        </section>

	<section title="SAML RADIUS Binding" anchor="SAML_RADIUS_binding">
	    <t>
		The SAML RADIUS binding defines how RADIUS <xref target="RFC2865"/> can be 
		used to enable a RADIUS client and server to exchange SAML protocol messages.
	    </t>
		<section title="Required Information">
		    <t>
			Identification: urn:ietf:params:xml:ns:abfab:bindings:radius
		    </t>
		    <t>
			Contact information: iesg@ietf.org
		    </t>
		    <t>
			Updates: None.
		    </t>
		</section>
		<section title="Operation">
		    <t>
			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 
			<xref target="I-D.ietf-radext-radsec" /> to provide confidentiality 
			and improve integrity protection. Implementations of this profile 
			MUST support RADIUS packet fragmentation 
			<xref target="I-D.perez-radext-radius-fragmentation" /> to permit 
			transport of large SAML messages.
		    </t>
		    <t>
			The system model used for SAML conversations over RADIUS is a simple 
			request-response model, using the RADIUS SAML-Message attribute 
			defined in <xref target='SAML_RADIUS_Message_attribute' /> to 
			encapsulate the SAML protocol messages.
		    </t>
		    <list style="numbers">
			<t>
			    The RADIUS client, acting as a SAML requester, MAY transmit 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 
			    <xref target="RFC4282" /> scheme. The SAML requester MUST NOT 
			    include more than one SAML request element.
			</t>
			<t>
			    The RADIUS server, acting as a SAML responder, MAY return a SAML 
			    protocol message within a RADIUS Access-Accept or Access-Reject 
			    message. These messages necessarily conclude a RADIUS exchange 
			    and therefore this is the only opportunity for the SAML responder 
			    to send a response in the context of this exchange. 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.
	        	</t>
	    	    </list>
	    	<t>
	            A SAML responder MAY also return an unsolicited response (a SAML response 
		    generated and emitted in the absence of a request from a SAML requester).
	   	 </t>
	    	<t>
		    This binding is intended to be composed with other uses of RADIUS, such as 
		    network access. Therefore, other arbitrary RADIUS attributes MAY be used in 
		    either the request or response.
	        </t>
	        <t>
		    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.
	        </t>
	        <t>
		    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.
	        </t>
		<section title="Use of XML Signatures">
		    <t>
			This bindings calls for the use of SAML elements that support XML 
			signatures. To promote interoperability implementations of this binding 
			MUST NOT require the use of XML signatures. Implementations MAY choose 
			to use XML signatures, but this usage is outside of the scope of this 
			binding.
		    </t>
		</section>
		<section title="Metadata Considerations">
		    <t>
			There are no metadata considerations particular to this binding.
		    </t>
		</section>
	    </section>
	</section>

	<section title="ABFAB Authentication Profile">
	    <t>
		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.
	    </t>
	    <section title="Required Information">
		<t>
		    Identification: urn:ietf:params:xml:ns:abfab:profiles:authentication
		</t>
		<t>
		    Contact information: iesg@ietf.org
		</t>
		<t>
		    SAML Confirmation Method Identifiers: The SAML V2.0 "sender vouches" 
		    confirmation method identifier, urn:oasis:names:tc:SAML:2.0:cm:sender-vouches, 
		    is used by this profile.
		</t>
		<t>
		    Updates: None.
		</t>
	    </section>
	    <section title="Profile Overview">
		<t>
		    To implement this scenario, a profile of the SAML Authentication Request 
		    protocol is used in conjuction with the SAML RADIUS binding defined in 
		    <xref target="SAML_RADIUS_binding" /> and the GSS EAP mechanism
		    <xref target="I-D.ietf-abfab-gss-eap" />.
		</t>
		<t>
		    This profile is based on the SAML V2.0 Web Browser Single Sign-On Profile 
		    <xref target="OASIS.saml-profiles-2.0-os" />. There are some important 
		    differences, specifically:
		</t>
		<list style="hanging">
		    <t hangText="Authentication:">
			This profile requires the use of a particular authentication
			framework (namely the GSS EAP mechanism), although not a particular EAP 
			authentication method. This allows the profile to build on the EAP, AAA 
			and GSS frameworks that comprise the core of the ABFAB architecture.
		    </t>
		    <t hangText="Bindings:">
			This profile does not require the use of HTTP-based bindings. Instead all 
			SAML protocol messages are transported using the SAML RADIUS binding 
			defined in <xref target="SAML_RADIUS_binding" />. This is intended to 
			reduce the number of bindings that implementations must support to be 
			interoperable.
		    </t>
		    <t hangText="Requests:">
			The profile does not permit the Relying Party to name the 
			<saml:Subject> of the <samlp:AuthnRequest>. This is intended 
			to simplify implementation and interoperability.
		    </t>
		    <t hangText="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 discretion of 
			the Identity Provider. This is intended to simplify implementation and
			interoperability.
		    </t>
		</list>
	        <figure anchor="AAP_swimlane">
		    <preamble>
		        <xref target="AAP_swimlane" /> below illustrates the flow of messages 
			within this profile.
		    </preamble>
		    <artwork>
  User Agent          Relying Party             Identity Provider
      |	                    |                           |
      |	        (1)         |                           |
      | - - - - - - - - - > |                           |
      |	                    |                           |
      |	                    |            (2)            |
      |	                    | - - - - - - - - - - - - > |
      |                     |                           |
      |	             (3)    |                           |
      | < - - - - - - - - - |- - - - - - - - - - - - -> |
      |                     |                           |
      |	                    |            (4)            |
      |                     | < - - - - - - - - - - - - |
      |	                    |				|
      |	        (5)         |                           |
      | < - - - - - - - - - |                           |
      |	                    |                           |
      V                     V                           V
		    </artwork>
		    <postamble>
		        The following steps are described by the profile. Within an individual 
			step, there may be one or more actual message exchanges.
		    </postamble>
	        </figure>
		<list style="numbers">
		    <t>
			User Agent Request to Relying Party (<xref target="AAP_UA2RP" />): 
			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.
		    </t>
		    <t>
			Relying Party Issues <samlp:AuthnRequest> to Identity Provider 
			(<xref target="RP2IDP" />). In step 2, the Relying Party may optionally 
			issue a <samlp:AuthnRequest> message to be delivered to the Identity 
			Provider using the SAML RADIUS binding.
		    </t>
		    <t>
			Identity Provider Identifies Principal (<xref target="IDP2P" />). 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 if provided.
		    </t>
		    <t>
			Identity Provider Issues <samlp:Response> to Relying Party 
			(<xref target="IDP2RP" />). 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.
		    </t>
		    <t>
			Relying Party Grants or Denies Access to Principal (<xref target="RP2P" />). 
			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.
		    </t>
		</list>
	    </section>
	    <section title="Profile Description">
		<t>
		    The ABFAB Authentication Profile is a profile of the SAML V2.0 
		    Authentication Request Protocol <xref target="OASIS.saml-core-2.0-os" />. Where 
		    this specification conflicts with Core, the former takes precedence.
		</t>
	        <section title="User Agent Request to Relying Party" anchor="AAP_UA2RP">
		    <t>
			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.
		    </t>
	        </section>
	        <section title="Relying Party Issues <samlp:AuthnRequest> to Identity Provider" anchor="RP2IDP">
		    <t>
			The Relying Party, on receiving the EAP-Identity/Response message from 
			the User Agent, MUST send it towards the Identity Provider using RADIUS 
			as described in <xref target="RFC3579"/>. The Relying Party MAY include a 
			<samlp:AuthnRequest> within this RADIUS Access-Request message using 
			the SAML RADIUS binding. The next hop destination MAY be the Identity 
			Provider or alternatively an intermediate RADIUS proxy.
		    </t>
		    <t>
			Profile-specific rules for the contents of the <samlp:AuthnRequest> 
			element are given in <xref target="AAP_ARP_Usage" />.
		    </t>
	        </section>
	        <section title="Identity Provider Identifies Principal" anchor="IDP2P">
		    <t>
			The Identity Provider MUST establish the identity of the Principal using 
			EAP authentication, or else it will return an error. If the ForceAuthn 
			attribute on the <samlp:AuthnRequest> element (if sent by the requester)
			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 <xref target="I-D.ietf-abfab-gss-eap" />
			and any others called out in the <samlp:AuthnRequest> message.
		    </t>
	        </section>
	        <section title="Identity Provider Issues <samlp:Response> to Relying Party" anchor="IDP2RP">
		    <t>
			The Identity Provider MUST conclude the EAP authentication in a manner 
			consistent with the EAP authentication result, and MAY issue a 
			<samlp:Response> message to the Relying Party consisent with the 
			authentication result and as described in 
			<xref target="OASIS.saml-core-2.0-os" /> and delivered to the Relying 
			Party using the SAML RADIUS binding. 
		    </t>
		    <t>
			Profile-specific rules regarding the contents of the 
			<samlp:Response> element are given in <xref target="AAP_ARP_Response" />.
		    </t>
	        </section>
	        <section title="Relying Party Grants or Denies Access to Principal" anchor="RP2P">
		    <t>
			If issued by the Identity Provider, the Relying Party MUST process the 
			<samlp:Response> message and any enclosed <saml:Assertion> 
			elements as described in <xref target="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.
		    </t>
		    <t>
			To complete the profile, the Relying Party creates a GSS security context 
			for the User Agent.
		    </t>
		</section>
	    </section>
	    <section title="Use of Authentication Request Protocol">
		<t>
		    This profile is based on the Authentication Request Protocol defined in 
		    <xref target="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.
		</t>
		<section title="<samlp:AuthnRequest> Usage" anchor="AAP_ARP_Usage">
		    <t>
		        A Relying Party MAY include any message content described in 
			<xref target="OASIS.saml-core-2.0-os" />, section 3.4.1. All processing 
			rules are as defined in <xref target="OASIS.saml-core-2.0-os" />. 
		    </t>
		    <t>
		        If the Identity Provider cannot or will not satisfy the request, it MAY 
			respond with a <samlp:Response> message containing an appropriate 
			error status code or codes.
		    </t>
		    <t>
		        If the Relying Party 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.
		    </t>
		    <t>
		        The Relying Party MUST NOT include a <saml:Subject> element in 
			the request. The authenticated EAP Identity names the Principal of 
			the requested <samlp:AuthnRequest> to the Identity Provider.
		    </t>
		    <t>
		        The <samlp:AuthnRequest> message MAY be signed. Authentication 
			and integrity are also provided by the RADIUS SAML binding.
		    </t>
		</section>
		<section title="<samlp:Response message> Usage" anchor="AAP_ARP_Response">
		    <t>
			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:
		    </t>
		    <list style="symbols">
			<t>
			    It MAY be signed.
			</t>
			<t>
			    It MUST contain exactly one <saml:Assertion>. The 
			    <saml:Subject> element of this assertion MUST refer to the 
			    authenticated Principal.
			</t>
			<t>
			    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.
			</t>
			<t>
			    Other conditions MAY be included as requested by the Relying Party
			    or at the discretion of the Identity Provider. The Identity Provider 
			    is NOT obligated to honor the requested set of conditions in the 
			    <samlp:AuthnRequest>, if any.
			</t>
		    </list>
		</section>
		<section title="samlp:Response Message Processing Rules">
		    <t>
			The Relying Party MUST do the following:
		    </t>
		    <list style="symbols">
			<t>
			    Verify that the InResponseTo attribute in the sender-vouches 
			    <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.
			</t>
			<t>
			    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.
			</t>
			<t>
			    Verify that any assertions relied upon are valid according to 
			    processing rules in <xref target="OASIS.saml-core-2.0-os" />.
			</t>
			<t>
			    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.
			</t>
		    </list>
		</section>
		<section title="Unsolicited Responses">
		    <t>
			An Identity Provider MAY initiate this profile by delivering an unsolicited <samlp:Response> message 
			to a Relying Party.
		    </t>
		    <t>
			An unsolicited <samlp:Response> MUST NOT contain an InResponseTo attribute, nor should any sender-vouches
			<saml:SubjectConfirmationData> elements contain one.
		    </t>
		</section>
		<section title="Use of the SAML RADIUS Binding">
		    <t>
			It is RECOMMENDED that the RADIUS exchange is protected using TLS encryption for RADIUS 
			<xref target="I-D.ietf-radext-radsec" /> to provide confidentiality and improve integrity protection.
		    </t>
		</section>
		<section title="Use of XML Signatures">
		    <t>
			This profile calls for the use of SAML elements that support XML signatures. To promote interoperability
			implementations of this profile MUST NOT require the use of XML signatures. Implementations 
			MAY choose to use XML signatures, but this usage is outside of the scope of this profile.
		    </t>
		</section>
		<section title="Metadata Considerations">
		    <t>
			There are no metadata considerations particular to this binding.
		    </t>
		</section>
	    </section>
	</section>

        <section title="ABFAB Assertion Query/Request Profile">
	    <t>
		This profile builds on the SAML V2.0 Assertion Query/Request Profile defined by
		<xref target="OASIS.saml-profiles-2.0-os" />. That profile describes the use of the 
		Assertion Query and Request Protocol defined by section 3.3 of <xref target="OASIS.saml-core-2.0-os" />
		with synchronous bindings, such as the SOAP binding defined in <xref target="OASIS.saml-bindings-2.0-os" /> 
		or the SAML RADIUS binding defined elsewhere in this document.
	    </t>
	    <t>
		While the SAML V2.0 Assertion Query/Request Profile is independent of the underlying binding, 
		it is nonetheless useful to describe the use of this profile with the SAML RADIUS binding in the interests of
		promoting interoperable implementations, particularly as the SAML V2.0 Assertion Query/Request Profile
		is most frequently discussed and implemented in the context of the SOAP binding.
	    </t>
	    <section title="Required Information">
		<t>
		    Identification: urn:ietf:params:xml:ns:abfab:profiles:query
		</t>
		<t>
		    Contact information: iesg@ietf.org
		</t>
		<t>
		    Description: Given below.
		</t>
		<t>
		    Updates: None.
		</t>
	    </section>
	    <section title="Profile Overview">
		<t>
		    As with the SAML V2.0 Assertion Query/Request Profile defined by <xref target="OASIS.saml-profiles-2.0-os" /> 
		    the message exchange and basic processing rules that govern this profile are largely defined by Section 3.3 of 
		    <xref target="OASIS.saml-core-2.0-os" /> that defines the messages to be exchanged, in combination 
		    with the binding used to exchange the messages. The SAML RADIUS binding described in this document 
		    defines the binding of the message exchange to RADIUS. Unless specifically noted here, all 
		    requirements defined in those specifications apply.
		</t>
	        <figure anchor="AAQRP_swimlane">
		    <preamble>
		        <xref target="AAQRP_swimlane" /> below illustrates the basic template for the query/request profile.
		    </preamble>
		    <artwork>
  SAML Requester                                  SAML Authority 
      |	                                                |
      |	                      (1)                       |
      |	- - - - - - - - - - - - - - - - - - - - - - - > |
      |                                                 |
      |	                      (2)                       |
      | < - - - - - - - - - - - - - - - - - - - - - - - |
      |                                                 |
      |	                                                |
      V                                                 V
		    </artwork>
		    <postamble>
		        The following steps are described by the profile.
		    </postamble>
	        </figure>
		<list style="numbers">
		    <t>
			Query/Request issued by SAML Requester: In step 1, a SAML requester initiates the profile by sending an
			<AssertionIDRequest>, <SubjectQuery>, <AuthnQuery>, <AttributeQuery>, or 
			<AuthzDecisionQuery> message to a SAML authority.
		    </t>
		    <t>
			<Response> issued by SAML Authority: In step 2, the responding SAML authority (after processing the 
			query or request) issues a <Response> message to the SAML requester.
		    </t>
		</list>
	    </section>
	    <section title="Profile Description">
		<section title="Differences from the SAML V2.0 Assertion Query/Request Profile">
		    <t>
			This profile is identical to the SAML V2.0 Assertion Query/Request Profile, with the following exceptions:
		    </t>
		    <list style="symbols">
			<t>
			    In respect to section 6.3.1 and 6.5, this profile does not consider the use of metadata 
			    (as in <xref target="OASIS.saml-metadata-2.0-os" />); see <xref target="AAQRP_MC" />.
			</t>
			<t>
			    In respect to sections 6.3.2, 6.4.1 and 6.4.2, this profile additionally stipulates that implementations
			    of this profile MUST NOT require the use of XML signatures; see <xref"AAQRP_XS" />.
			</t>
		    </list>
		</section>
		<section title="Use of the SAML RADIUS Binding">
		    <t>
			It is RECOMMENDED that the RADIUS exchange is protected using TLS encryption for RADIUS 
			<xref target="I-D.ietf-radext-radsec" /> to provide confidentiality and improve integrity protection.
		    </t>
		</section>
		<section title="Use of XML Signatures" anchor="AAQRP_XS">
		    <t>
			This profile calls for the use of SAML elements that support XML signatures. To promote interoperability
			implementations of this profile MUST NOT require the use of XML signatures. Implementations 
			MAY choose to use XML signatures, but this usage is outside of the scope of this profile.
		    </t>
		</section>
		<section title="Metadata Considerations" anchor="AAQRP_MC">
		    <t>
			There are no metadata considerations particular to this binding.
		    </t>
		</section>
	    </section>
	</section>

	<section title="Acknowledgements">
	    <t>TODO: Where should these go? Need to acknowledge OASIS SSTC, UoMurcia, Scott and Steven.</t>
	</section>

        <section title="Security Considerations">
            <t>
                TODO
            </t>
        </section>
        
        <section title="IANA Considerations">
            <t>
                Assignments of additional enumerated values for the RADIUS attributes defined in this document are to be processed as described in <xref target="RFC3575" />, subject to the additional requirements of a published specification.
            </t>
        </section>        
        
    </middle>

    <back>
        <references title="Normative References">
            &rfc2119;
	    &I-D.draft-ietf-radext-radsec;
	    &I-D.ietf-abfab-gss-eap;
	    &I-D.draft-perez-radext-radius-fragmentation;
        </references>

        <references title="Informative References">
            &rfc2865;
	    &rfc3575;
	    &rfc3579;
	    &rfc3588;
	    &rfc4282;
	    &I-D.jones-diameter-abfab;
	    &I-D.ietf-abfab-arch;
	    &SAML2Bindings;
	    &SAML2Core;
	    &SAML2Profiles;
	    &SAML2Metadata;
        </references>
    </back>
</rfc>

PAFTECH AB 2003-20262026-04-24 02:54:39