draft-uma-core.xml

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<rfc category="std" docName="draft-uma-core-v1-00.txt" ipr="trust200902">
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  <front>
    <title abbrev="UMA Core Protocol">User-Managed Access (UMA) Core
    Protocol</title>

    <author fullname="Christian Scholz" initials="C" role="editor"
            surname="Scholz">
      <organization>COM.lounge GmbH</organization>

      <address>
        <email>cs@comlounge.net</email>

        <uri>http://comlounge.net</uri>
      </address>
    </author>

    <author fullname="Paul Bryan" initials="P" surname="Bryan">
      <organization>?</organization>

      <address>
        <email>email@pbryan.net</email>

        <uri>http://pbryan.net</uri>
      </address>
    </author>

    <author fullname="Maciej Machulak" initials="M" surname="Machulak">
      <organization>Newcastle University</organization>

      <address>
        <email>m.p.machulak@ncl.ac.uk</email>

        <uri>http://ncl.ac.uk/</uri>
      </address>
    </author>

    <author fullname="Eve Maler" initials="E" surname="Maler">
      <organization>PayPal</organization>

      <address>
        <email>eve@xmlgrrl.com</email>

        <uri>http://www.paypal.com/</uri>
      </address>
    </author>

    <date year="2010" />

    <abstract>
      <t>This specification defines the User-Managed Access (UMA) core
      protocol. This protocol provides a method for users to control access to
      their protected resources, residing on any number of host sites, through
      an authorization manager that makes access decisions based on user
      policy.</t>

      <t>This document is a product of the User-Managed Access Work Group of
      the Kantara Initiative. It is currently under active development. It has
      not yet been submitted to the IETF. The User-Managed Access Work Group
      operates under Kantara IPR Policy - Option Patent and Copyright:
      Reciprocal Royalty Free with Opt-Out to Reasonable And Non
      discriminatory (RAND) and the publication of this document is governed
      by the policies outlined in this option.</t>
    </abstract>
  </front>

  <middle>
    <section title="Introduction">
      <t>The User-Managed Access (UMA) core protocol provides a method, based
      on <xref target="OAuth2" /> (currently draft 10), for users to control
      access to their protected resources, residing on any number of host
      sites, through an authorization manager that makes access decisions
      based on user policy.</t>

      <t>For example, a web user (authorizing user) can authorize a web app
      (requester) to gain one-time or ongoing access to a resource containing
      his home address stored at a "personal data store" service (host), by
      telling the host to act on access decisions made by his authorization
      decision-making service (authorization manager or AM). The requesting
      party might be an e-commerce company whose site is acting on behalf of
      the user himself to assist him in arranging for shipping a purchased
      item, or it might be his friend who is using an online address book
      service to collect addresses, or it might be a survey company that uses
      an online service to compile population demographics.</t>

      <t>In enterprise settings, application access management often involves
      letting back-office applications serve only as policy enforcement points
      (PEPs), depending entirely on access decisions coming from a central
      policy decision point (PDP) to govern the access they give to
      requesters. This separation eases auditing and allows policy
      administration to scale in several dimensions. UMA makes use of this
      separation, letting the authorizing user serve as a policy administrator
      crafting authorization strategies on his or her own behalf.</t>

      <t>The UMA protocol profiles and extends <xref target="OAuth2" />,
      applying two instances of OAuth flow patterns among the entities.</t>

      <t>First, UMA allows a host to trust an AM to which it has been
      introduced dynamically. To accomplish this, the host acquires a host
      access token that it can subsequently use in interacting with a set of
      host-specific protected resources at the AM. These resources can be
      considered an OAuth-protected API. Thus, when the host accesses these
      resources, it acts in the role of an OAuth client while the AM acts in
      the dual roles of an OAuth resource server and authorization server.</t>

      <t>Subsequently, when a requester interacts with the AM and the host in
      the course of getting access to some protected resource on the host, the
      requester acts in the role of an OAuth client to get and use a requester
      access token; the host acts in the role of an OAuth resource server; and
      the AM acts in the role of an OAuth authorization server.</t>

      <t>UMA has the following major steps: <list style="numbers">
          <t>The authorizing user introduces a host to an AM.</t>

          <t>The requester gets an access token from the AM.</t>

          <t>The requester wields the access token at the host to gain
          access.</t>
        </list></t>

      <section title="Notational 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 <xref
        target="RFC2119" />.</t>

        <t>This document uses the Augmented Backus-Naur Form (ABNF) notation
        of <xref target="I-D.ietf-httpbis-p1-messaging" />. Additionally, the
        realm and auth-param rules are included from <xref
        target="RFC2617" />.</t>

        <t>Unless otherwise noted, all the protocol parameter names and values
        are case sensitive.</t>
      </section>

      <section title="Terminology">
        <t>
          <list hangIndent="6" style="hanging">
            <t hangText="authorizing user"><vspace />An UMA-defined variant of
            an OAuth resource owner; a web user who configures an
            authorization manager with policies that control how it makes
            access decisions when a requester attempts to access a protected
            resource at a host.</t>

            <t hangText="authorization manager"><vspace />An UMA-defined
            variant of an OAuth authorization server that carries out an
            authorizing user's policies governing access to a protected
            resource.</t>

            <t hangText="protected resource"><vspace />An access-restricted
            resource at a host.</t>

            <t hangText="host"><vspace />An UMA-defined variant of an OAuth
            resource server that enforces access to the protected resources it
            hosts, as decided by an authorization manager.</t>

            <t hangText="host access token"><vspace />An access token
            representing the authorizing user's consent for a host to trust a
            particular authorization manager for access decisions about
            resources hosted there.</t>

            <t hangText="claim"><vspace />A statement of the value or values
            of one or more identity attributes of a requesting party. Claims
            are conveyed by a requester on behalf of a requesting party to an
            authorization manager in an attempt to satisfy an authorizing
            user's policy.</t>

            <t hangText="requester"><vspace />An UMA-defined variant of an
            OAuth client that seeks access to a protected resource.</t>

            <t hangText="requester access token"><vspace />An access token
            representing the authorizing user's consent for a requester's
            access to particular resources at a host.</t>

            <t hangText="requesting party"><vspace />A web user, or a
            corporation (or other legal person), that uses a requester to seek
            access to a protected resource.</t>
          </list>
        </t>
      </section>
    </section>

    <section title="Step 1: Authorizing user introduces host to AM">
      <t>In order for a host to be able to delegate authorization to an AM,
      the authorizing user must introduce the host to the AM. The result is as
      follows: <list style="symbols">
          <t>The host has received metadata about the AM, such as OAuth
          endpoints.</t>

          <t>The host has received an OAuth access token (known as the host
          access token) that represents the authorizing user's approval for
          the host to work with this AM in protecting resources. This token is
          used when the host makes requests at host-specific AM endpoints.</t>

          <t>The AM has optionally acquired information about scopes on the
          host it is supposed to protect on behalf of the user.</t>
        </list></t>

      <t>The following substeps are performed in order to achieve these
      results: <list style="numbers">
          <t>The host looks up the AM's metadata and learns about its API
          endpoints and supported formats.</t>

          <t>If the host has not yet obtained an OAuth client identifier and
          optional secret from the AM, it registers with and binds to the AM
          dynamically, for example via <xref
          target="Dyn-Reg">Dyn-Reg</xref>.</t>

          <t>The host obtains an access token from the AM with the authorizing
          user's consent, by following the OAuth 2.0 web server profile.</t>

          <t>The host optionally registers scopes with the AM that are
          intended to be protected, via [[draft-uma-resource-reg]].</t>
        </list></t>

      <section title="Host looks up AM metadata">
        <t>The host needs to learn the OAuth- and UMA-related endpoints of the
        AM before they can begin interacting. The authorizing user might
        provide the AM's location to get the host started in this process, for
        example typing a URL into a web form field or clicking a button, or
        the host might have been configured to work with a single AM without
        requiring any user input. The exact process is beyond the scope of
        this specification, and it is up to the host to choose a method.</t>

        <t>From the data provided, discovered, or configured, the host MUST
        retrieve the hostmeta document as described in section 2 of <xref
        target="hostmeta">hostmeta</xref>. For example, if the user supplied
        "am.example.com" as the authorization manager's domain, the host
        creates the URL "https://am.example.com/.well-known/host-meta" and
        performs a GET request on it.</t>

        <t>The AM MUST provide a XRD 1.0 formatted document at the hostmeta
        location, documenting the following: <list style="symbols">
            <t>One set of OAuth 2.0 end-user authorization and token endpoints
            for the host to use</t>

            <t>One set of OAuth 2.0 end-user authorization and token endpoints
            for requesters to use, which the host will need to provide to
            unauthorized requesters</t>

            <t>Optionally, the location of an UMA token validation endpoint
            for the host to use in validating access tokens received from a
            requester in step 3</t>

            <t>At least one access token format the AM produces</t>

            <t>Any claims formats the AM supports</t>
          </list></t>

        <t>(Note that the method of endpoint discovery defined here is
        intended to be compatible with the ultimate dynamic discovery,
        registration, and binding solution proposed by the OAuth group. The
        UMA group has proposed a generic solution at <xref
        target="Dyn-Reg">Dyn-Reg</xref>, with which this discovery step is
        compatible.)</t>

        <t>Property type values for access token and claim format information:
        <list hangIndent="6" style="hanging">
            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/token_formats"><vspace />
            REQUIRED (one or more). Access token format produced by this AM.
            Options are (@@TBS).</t>

            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/claim_formats"><vspace />
            OPTIONAL (zero or more). Claim format supported by this AM.
            Options are (@@TBS).</t>
          </list></t>

        <t>Link relationship rel values for the endpoint URLs for the host:
        <list hangIndent="6" style="hanging">
            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/host_user_uri"><vspace />REQUIRED.
            Available HTTP methods are as defined by [[OAuth20]] for an
            end-user authorization endpoint. Supplies the endpoint hosts
            should use to gather the consent of the authorizing user for a
            host-AM relationship.</t>

            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/host_token_uri"><vspace />REQUIRED.
            Available HTTP methods are as defined by [[OAuth20]] for a token
            issuance endpoint. Supplies the endpoint hosts should use to ask
            for a host access token.</t>

            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/host_registration_uri"><vspace />REQUIRED.
            Supports the POST HTTP method, accompanied by a host access token.
            Supplies the endpoint hosts should use for registering information
            with the AM, such as descriptions of resources that are to be
            protected by this AM (as defined in [[draft-uma-resource-reg]]).
            The AM SHOULD require the use of a transport-layer security
            mechanism such as TLS when the host sends requests to the host
            registration endpoint.</t>

            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/host_token_validation_uri"><vspace />OPTIONAL.
            Supports the POST HTTP method, accompanied by a host access token.
            Supplies the endpoint hosts should use to request validation of
            access tokens presented to them by requesters in Step 3. This
            endpoint SHOULD require the use of a transport-layer security
            mechanism such as TLS.</t>
          </list></t>

        <t>Link relationship rel values for the endpoint URLs for the
        requester: <list hangIndent="6" style="hanging">
            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/req_user_uri"><vspace />
            REQUIRED. Available HTTP methods are as defined by <xref
            target="OAuth2" /> for a user authorization URL. Supplies the user
            authorization URL requesters should use to gather the consent of
            the authorizing user for user delegation flows in synchronous
            person-to-service sharing scenarios. (See Section @@TODO for the
            definition of this UMA-specific client profile.) This endpoint
            SHOULD require the use of a transport-layer security mechanism
            such as TLS.</t>

            <t
            hangText="http://kantarainitiative.org/confluence/display/uma/req_token_uri"><vspace />
            REQUIRED. Available HTTP methods are as defined by <xref
            target="OAuth2" /> for a token issuance URL. Supplies the token
            URL requesters should use to ask for an access token in step 2.
            This endpoint SHOULD require the use of a transport-layer security
            mechanism such as TLS.</t>
          </list></t>

        <figure>
          <preamble>For example:</preamble>

          <artwork><![CDATA[
      
<!-- Applies to both hosts and requesters --> 
<Property 
  type="http://wguma.org/confluence/display/uma/token_formats">
  saml
</Property>
<Property 
  type="http://wguma.org/confluence/display/uma/claim_formats">
  json
</Property>

<!-- Host "authorization API" --> 
<Link 
rel="http://wguma.org/confluence/display/uma/host_token_uri"
href="https://am.example.com/host/token_uri"></Link> 
<Link 
rel="http://wguma.org/confluence/display/uma/host_user_uri"
href="https://am.example.com/host/user_uri"></Link> 
<<<<<<< HEAD
<Link 
rel="http://wguma.org/confluence/display/uma/host_resource_details_uri"
=======
<Link rel="http://kantarainitiative.org/confluence/display/uma/host_registration_uri"
>>>>>>> b739d760a257c5b06aff0e1b0b7a962418425a08
href="https://am.example.com/host/resource_details_uri"></Link> 
<Link 
rel="http://wguma.org/confluence/display/uma/host_token_validation_uri"
href="https://am.example.com/host/token_validation_uri"></Link> 

<!-- Requester token-getting endpoints --> 
<Link rel="http://wguma.org/confluence/display/uma/req_token_uri"
href="https://am.example.com/requester/token_uri"></Link> 
<Link rel="http://wguma.org/confluence/display/uma/req_user_uri"
href="https://am.example.com/requester/user_uri"></Link>

       ]]></artwork>
        </figure>
      </section>

      <section title="Host dynamically registers with AM">
        <t>If the host has not already obtained a client identifier and
        optional secret from this AM previously, in this substep it MUST do
        so, if the AM supports dynamic registration, in order to engage in
        OAuth-based interactions with it. It is anticipated that the OAuth
        group will define a solution for dynamic registration and
        client-authorization server binding; the UMA proposal for this is at
        <xref target="Dyn-Reg">Dyn-Reg</xref>.</t>
      </section>

      <section title="Host obtains host access token">
        <t>In this substep, the host acquires a host access token from the AM
        that represents the approval of the authorizing user for the host to
        trust this AM for protecting resources for this user.</t>

        <t>The host MUST use the <xref target="OAuth2">OAuth2</xref> web
        server profile (@@TODO: subsequently profile it to use UMA recursively
        for claims-getting purposes?), utilizing the end-user authorization
        and token endpoints discovered earlier. The host acts in the role of
        an OAuth client; the authorizing user acts in the role of an OAuth
        end-user resource owner; and the AM, though the provided endpoint
        URLs, acts in the role of an OAuth authorization server.</t>
      </section>

      <section title="Host registers resources to be protected">
        <t>Once the host has received an access token, in this substep it MAY,
        immediately or at any time until user authorization is revoked,
        present the token at the AM's host_registration_uri endpoint in the
        manner defined in [[draft-uma-resource-reg]] in order to register
        resources that this AM needs to protect.</t>

        <t>Note that the host is free to offer the option to protect any
        subset of the user's resources using different AMs or other means
        entirely, or to protect some resources and not others; any such
        partitioning by the host or user is outside the scope of this
        specification.</t>
      </section>
    </section>

    <section title="Step 2: Requester gets access token from AM">
      <t>In this step, the requester in the role of an OAuth client seeks a
      requester access token from the AM in the role of OAuth authorization
      server.</t>

      <t>This step extends OAuth to add a third possible response from the AM
      in addition to successful vs. unsuccessful access token responses. The
      third option is to ask for more information from the requesting party,
      in the form of claims. It also profiles all OAuth profiles to specify
      how the requester must supply scope values in asking for
      authorization.</t>

      <t>This step has the following substeps: <list style="numbers">
          <t>Requester attempts to access resource at host and is given AM's
          req_token_uri endpoint (and also AM's req_user_uri endpoint,
          depending on the sharing profile).</t>

          <t>Requester visits req_token_uri endpoint, indicating its desired
          scope of access.</t>

          <t>AM either provides access token, rejects authorization, or asks
          requester for claims.</t>

          <t>Requester provides claims as requested, until access token
          request either succeeds or fails definitively.</t>
        </list></t>

      <t>The substep detail is as follows.</t>

      <t>If the requester knows, by whatever means, the access token URL for
      the AM that is protecting the desired resource and how to express its
      desired scope of access without first approaching the host, it MAY
      proceed directly to that URL. Alternatively, it MAY attempt to access
      the resource directly at the host; if it does not present an access
      token, the host MUST respond with a challenge, using the "HTTP 401
      Unauthorized" code and providing the req_token_uri endpoint (and the
      req_user_uri endpoint, depending on the sharing profile) in the HTTP
      header "WWW-Authenticate".</t>

      <t>The requester submits a GET request to the access token URL,
      providing the desired scope of access in the "scope" parameter. [@@TBS:
      Rework this to describe how the desired scope information is provided
      (e.g. whether it is in plain text or is passed through in protected form
      from the host) and whether there are extension points to allow other
      information to be provided. Provide code examples.]</t>

      <t>The requester performs a GET on the access token URL, using the
      standard HTTP "Accept" header to express the acceptable media type(s) of
      any claims-required list. The AM responds in one of three ways: <list
          style="symbols">
          <t>If the AM requires no claims from the requester in order to grant
          authorization based on user policy, it responds with a successful
          OAuth access token response. The response MAY include a refresh
          token URL for the requester to attempt to use subsequently in
          reusing this authorization to generate future access tokens.</t>

          <t>If the requester is definitively not authorized according to user
          policy, the AM responds with an unsuccessful OAuth access token
          response and the authorization negotiation phase ends.</t>

          <t>If user policy demands more information from the requester, the
          AM responds with a claims-required response containing a
          claims-required list. The list SHOULD use the media type that was
          indicated by the requester as acceptable.</t>
        </list></t>

      <t>On receiving a claims-required list, the requester performs a POST to
      the authorization negotiation URL supplying a claims document,
      specifying its type in the "Content-Type" header. The AM rejects the
      document if it does not recognize its type. If the AM accepts the
      document, it responds with a successful or unsuccessful access token
      response as detailed above, or with another claims-required response.
      [Eventually need a special claims response that allows for the
      trusted-claims model to unfold.]</t>

      <t>If the access token request is successful, the access token supplied
      MUST be in one of the formats contemporaneously advertised in the AM's
      host-meta metadata.</t>

      <t>This specification does not define the formats of required-claims
      lists and claims documents. It may ultimately put minimum conformance
      requirements on requesters and AMs to handle particular claim formats
      defined in other specifications, as well as specifying requirements that
      claim formats seeking consideration for use in UMA must meet. One
      candidate specification for lightweight claims requests and responses is
      <xref target="Claims2.0">Claims2.0</xref>.</t>

      <section title="Sharing profiles">
        <t>Access to the protected resource may be sought by one of a variety
        of parties. In OAuth, typically the same end-user resource owner (who
        authenticates to the authorization server to grant access) also
        operates the client application; UMA refers to this as "person-to-self
        sharing" (in technical terms, an authorizing user who is the same
        natural person as a requesting party operating a requester). UMA also
        allows for "person-to-person sharing", in which the requesting party
        is a natural person different from the authorizing user, and
        "person-to-organization sharing", in which the requesting party is a
        corporation or other legal person.</t>

        <t>A requester mediating person-to-person or person-to-organization
        sharing MUST use an OAuth profile (UMA-extended to include claims
        support, as specified above) that does not involve use of the
        req_user_uri endpoint, to allow for issuing an access token that does
        not require the authorizing user's presence at the time of issuance. A
        requester mediating person-to-self sharing MUST use OAuth profile
        (UMA-extended to include claims support, as specified above) that
        involves use of the req_user_uri endpoint, such that this person
        synchronously authorizes access through first presenting user
        credentials to the AM.</t>
      </section>
    </section>

    <section title="Step 3: Requester wields access token at host to gain access">
      <t>In this step, the requester in the role of an OAuth client interacts
      with the host in the role of an OAuth resource server in order to gain
      access to the protected resource. This step extends OAuth to require the
      host to validate the token at the authorization manager instead of
      locally.</t>

      <t>(This step is currently defined to provide a baseline of
      functionality and security that relies on non-cryptographic methods such
      as a short-lived requester access token; it is anticipated that
      OAuth-compatible digital signature-based methods for authenticating the
      requester more strongly will be added.) This step has the following
      substeps: <list style="numbers">
          <t>Requester presents the requester access token to the host in
          attempting to access desired resource.</t>

          <t>Host asks AM to validate the requester access token.</t>

          <t>AM validates the token and responds with either a valid response
          or an error response; host passes through the result.</t>
        </list></t>

      <section title="Requester attempts access">
        <t>The requester attempts to access the protected resource at the host
        by presenting the request access token it was issued by the AM in step
        2, using the process described in section 5 of <xref
        target="OAuth2">OAuth2</xref>.</t>

        <t>If the the request is invalid, for example because it is missing an
        access token, the host issues an invalid_request error response as
        described in section 5.2.1 of <xref target="OAuth2">OAuth2</xref> and
        does not proceed.</t>
      </section>

      <section title="Host asks AM to validate requester access token">
        <t>The host verifies the requester access token by sending it to the
        AM's token verification endpoint. The AM validates the requester
        access token and returns the result to the host. The AM MUST validate
        the access token and ensure it has not expired and that the host it is
        used for is the one it was requested for.</t>

        <t>The request made by the host to the AM MUST be an OAuth-protected
        request itself, using the host access token obtained in step 1.</t>

        <t>The host's request to the AM is made with a POST containing the
        requester access token and the IP address of the requester's request.
        (The host MAY, at its discretion, instead supply the originating IP
        address indicated in the requester's X-Forwarded-For: header value.)
        The POST uses the "application/x-www-form-urlencoded" format as
        defined by [W3C.REC-html401-19991224]. The IP address or originating
        IP address is advisory only; the AM MAY ignore it for token validation
        purposes.</t>

        <figure>
          <preamble>Example of a request to the token verification endpoint
          that provides the host access token in the header:</preamble>

          <artwork><![CDATA[
POST /token_verification HTTP/1.1
Host: am.example.com
Authorization: OAuth vF9dft4qmT
Content-Type: application/x-www-form-urlencoded     

token=sbjsbhs(/SSJHBSUSSJHVhjsgvhsgvshgsv&ipaddr=192.168.1.1
       ]]></artwork>
        </figure>
      </section>

      <section title="Valid response">
        <t>After determining that the token is valid, the AM sends the host a
        response containing a list of scopes applying to this particular
        requester access token. The response usesa JSON document inside the
        body of an HTTP response using the 200 OK status code. The scopes come
        from a list of strings previously registered with the AM by the host
        (as specified in Step 1).</t>

        <figure>
          <preamble>Example:</preamble>

          <artwork><![CDATA[
HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: no-store

{
"scopes": ['read_private_photos', 'write_private_photos']
}       ]]></artwork>
        </figure>

        <t>The host MUST validate if one of the scopes is sufficient for
        requester to access the requested resource in the manner originally
        attempted. If it is, the host gives access in that manner.</t>
      </section>

      <section title="Error responses">
        <t>Ultimately the host is responsible for either granting the access
        the requester attempted, or returning an error response to the
        requester with a reason for the failure. <xref target="OAuth2" />
        defines several error responses for a resource server to return. UMA
        makes use of these error responses, but requires the host to
        "outsource" the determination of some error conditions to the AM.</t>

        <t>The host is responsible for determining "insufficient_scope". If
        the requester's attempted access does not match any of the scopes
        returned by the AM in its valid-token response to the host, the host
        returns an "insufficient_scope" error to the requester.</t>

        <t>The host is responsible for determining "invalid_request". If the
        requester's request was badly formed, the host returns an
        "invalid_request" error to the requester.</t>

        <t>If the AM determined that the requester access token is invalid, it
        returns an "invalid_requester_token" error response to the host.
        [@@TBS: Need to flesh out more and provide an example.] The host then
        returns an "invalid_token" response to the requester as described in
        section 5.2.1 of <xref target="OAuth2" />.</t>

        <t>If the AM determined that the requester access token has expired,
        it returns an "expired_requester_token" error response to the host.
        [@@TBS: Need to flesh out more and provide an example.] The host then
        returns an "invalid_token" response to the requester as described in
        section 5.2.1 of <xref target="OAuth2" />.</t>

        <t>If the host's token validation request message itself was badly
        formed, the AM returns an "invalid_request" error to the host. [@@Need
        to say what happens to the requester after that?]</t>
      </section>
    </section>

    <section title="Security Considerations">
      <t>@@TODO: Provide commentary on any requirements layered on the
      forthcoming OAuth security considerations section; discuss UMA-layer
      implications for more meaningful authentication of requesters/requesting
      parties; discuss implications of user-mediated AM/host trust model;
      discuss short-lived token technique for lightweight requester
      correlation...</t>
    </section>

    <section title="Conformance">
      <t>This section outlines conformance requirements for various entities
      implementing UMA endpoints. Currently two levels of conformance are
      defined: minimal and full. (Other types or levels may ultimately be
      defined in this specification or in other specifications that profile or
      extend this one.)</t>

      <t>This specification has dependencies on other specifications, as
      follows:<list style="symbols">
          <t>OAuth 2.0: AMs, hosts, and requesters MUST support OAuth 2.0
          features named in this specification for minimal conformance. For
          example, features related to refresh tokens, client secrets, and the
          web server profile are mentioned and support for them is
          REQUIRED.</t>

          <t>Dynamic registration: For full conformance, AMs MUST support
          dynamic registration. For minimal conformance, AMs are not required
          to support dynamic registration. Hosts need not support the
          requesting of dynamic registration at either conformance level.</t>

          <t>Resource registration: For minimal conformance, AMs and hosts
          MUST support resource registration.</t>
        </list></t>
    </section>

    <appendix title="Acknowledgements">
      <t><list style="symbols">
          <t>TBS</t>
        </list> [[ Add further WG contributors ]]</t>
    </appendix>

    <appendix title="Document History">
      <t>[[ to be removed by RFC editor before publication as an RFC ]]</t>
    </appendix>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2617.xml' ?>

      <?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml' ?>

      <?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.5785.xml' ?>

      <?rfc include='http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-hammer-hostmeta-13.xml'?>

      <?rfc include='http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-ietf-httpbis-p1-messaging-09.xml'?>
<<<<<<< HEAD
         <reference anchor="OAuth2"
       target="http://www.ietf.org/id/draft-ietf-oauth-v2-10.txt">
       <front>
         <title>The OAuth 2.0 Protocol</title>
         <author initials="E." surname="Hammer-Lahav">
           <organization>IETF</organization>
         </author>
         <date year="2010" />
       </front>
     </reference>
         <reference anchor="Dyn-Reg"
       target="http://tools.ietf.org/html/draft-oauth-dyn-reg-v1-00">
       <front>
         <title>OAuth Dynamic Client Registration Protocol</title>
         <author initials="C." surname="Scholz">
           <organization>IETF</organization>
         </author>
         <date year="2010" />
       </front>
     </reference>
     <reference anchor="hostmeta"
       target="http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-hammer-hostmeta-13.xml">
       <front>
         <title>Web Host Metadata</title>
         <author initials="E." surname="Hammer-Lahav">
           <organization>Yahoo!</organization>
         </author>
         <date year="2010" />
       </front>
     </reference>

     <reference anchor="Claims2.0"
       target="http://wguma.org/confluence/display/uma/Claims+2.0">
       <front>
         <title>Claims 2.0</title>
         <author initials="E." surname="Maler">
           <organization>Kantara</organization>
         </author>
         <date year="2010" />
       </front>
     </reference>
<!--
=======

      <reference anchor="OAuth2"
                 target="http://www.ietf.org/id/draft-ietf-oauth-v2-10.txt">
        <front>
          <title>The OAuth 2.0 Protocol</title>

          <author initials="E." surname="Hammer-Lahav">
            <organization>IETF</organization>
          </author>

          <date year="2010" />
        </front>
      </reference>

      <reference anchor="Dyn-Reg"
                 target="http://tools.ietf.org/html/draft-oauth-dyn-reg-v1-00">
        <front>
          <title>OAuth Dynamic Client Registration Protocol</title>

          <author initials="C." surname="Scholz">
            <organization>IETF</organization>
          </author>

          <date year="2010" />
        </front>
      </reference>

      <reference anchor="hostmeta"
                 target="http://xml.resource.org/public/rfc/bibxml3/reference.I-D.draft-hammer-hostmeta-13.xml">
        <front>
          <title>Web Host Metadata</title>

          <author initials="E." surname="Hammer-Lahav">
            <organization>Yahoo!</organization>
          </author>

          <date year="2010" />
        </front>
      </reference>

      <reference anchor="Claims2.0"
                 target="http://kantarainitiative.org/confluence/display/uma/Claims+2.0">
        <front>
          <title>Claims 2.0</title>

          <author initials="E." surname="Maler">
            <organization>Kantara</organization>
          </author>

          <date year="2010" />
        </front>
      </reference>

      <!--
>>>>>>> b739d760a257c5b06aff0e1b0b7a962418425a08

      <?rfc include='http://xml.resource.org/public/rfc/bibxml/reference.RFC.2045.xml' ?>
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      <?rfc include='http://xml.resource.org/public/rfc/bibxml4/reference.W3C.REC-html401-19991224.xml' ?>
-->
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</rfc>