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Versions: 00 01

OAuth Working Group                                             M. Jones
Internet-Draft                                                 Microsoft
Intended status: Standards Track                                 P. Hunt
Expires: July 23, 2017                                            Oracle
                                                        January 19, 2017


                 OAuth 2.0 Protected Resource Metadata
                 draft-jones-oauth-resource-metadata-01

Abstract

   This specification defines a metadata format that an OAuth 2.0 client
   can use to obtain the information needed to interact with an OAuth
   2.0 protected resource.

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 July 23, 2017.

Copyright Notice

   Copyright (c) 2017 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
   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.




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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Notation and Conventions . . . . . . . . . .   3
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Protected Resource Metadata . . . . . . . . . . . . . . . . .   4
     2.1.  Signed Protected Resource Metadata  . . . . . . . . . . .   5
   3.  Obtaining Protected Resource Metadata . . . . . . . . . . . .   6
     3.1.  Protected Resource Metadata Request . . . . . . . . . . .   6
     3.2.  Protected Resource Metadata Response  . . . . . . . . . .   7
     3.3.  Protected Resource Metadata Validation  . . . . . . . . .   8
   4.  Authorization Server Metadata . . . . . . . . . . . . . . . .   8
   5.  String Operations . . . . . . . . . . . . . . . . . . . . . .   8
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
     6.1.  TLS Requirements  . . . . . . . . . . . . . . . . . . . .   9
     6.2.  Impersonation Attacks . . . . . . . . . . . . . . . . . .   9
     6.3.  Publishing Metadata in a Standard Format  . . . . . . . .  10
     6.4.  Authorization Servers . . . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
     7.1.  OAuth Protected Resource Metadata Registry  . . . . . . .  11
       7.1.1.  Registration Template . . . . . . . . . . . . . . . .  12
       7.1.2.  Initial Registry Contents . . . . . . . . . . . . . .  12
     7.2.  OAuth Authorization Server Metadata Registry  . . . . . .  14
       7.2.1.  Registry Contents . . . . . . . . . . . . . . . . . .  14
     7.3.  Well-Known URI Registry . . . . . . . . . . . . . . . . .  14
       7.3.1.  Registry Contents . . . . . . . . . . . . . . . . . .  14
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Appendix A.  Acknowledgements . . . . . . . . . . . . . . . . . .  17
   Appendix B.  Document History . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   This specification defines a metadata format enabling OAuth 2.0
   clients to obtain information needed to interact with an OAuth 2.0
   protected resource.  This specification is intentionally as parallel
   as possible to "OAuth 2.0 Dynamic Client Registration Protocol"
   [RFC7591], which enables a client to provide metadata about itself to
   an OAuth 2.0 authorization server and to OAuth 2.0 Authorization
   Server Metadata [OAuth.AuthorizationMetadata], which enables a client
   to obtain metadata about an OAuth 2.0 authorization server.

   The metadata for a protected resource is retrieved from a well-known
   location as a JSON [RFC7159] document, which declares information
   about its capabilities and optionally, its relationships to other
   services.  This process is described in Section 3.



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   This metadata can either be communicated in a self-asserted fashion
   or as a set of signed metadata values represented as claims in a JSON
   Web Token (JWT) [JWT].  In the JWT case, the issuer is vouching for
   the validity of the data about the protected resource.  This is
   analogous to the role that the Software Statement plays in OAuth
   Dynamic Client Registration [RFC7591].

   Each protected resource publishing metadata about itself makes its
   own metadata document available at a well-known location rooted at
   the protect resource's URL, even when the resource server implements
   multiple protected resources.  This prevents attackers from
   publishing metadata supposedly describing the protected resource, but
   that is not actually authoritative for the protected resource, as
   described in Section 6.2.

   The means by which the client obtains the location of the protected
   resource metadata document is out of scope.  In some cases, the
   location may be manually configured into the client.  In other cases,
   it may be dynamically discovered, for instance, through the use of
   WebFinger [RFC7033], in a manner related to the description in
   Section 2 of "OpenID Connect Discovery 1.0" [OpenID.Discovery].

1.1.  Requirements Notation and Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC
   2119 [RFC2119].

   All uses of JSON Web Signature (JWS) [JWS] and JSON Web Encryption
   (JWE) [JWE] data structures in this specification utilize the JWS
   Compact Serialization or the JWE Compact Serialization; the JWS JSON
   Serialization and the JWE JSON Serialization are not used.

1.2.  Terminology

   This specification uses the terms "Access Token", "Authorization
   Code", "Authorization Endpoint", "Authorization Grant",
   "Authorization Server", "Client", "Client Authentication", "Client
   Identifier", "Client Secret", "Grant Type", "Protected Resource",
   "Redirection URI", "Refresh Token", "Resource Owner", "Resource
   Server", "Response Type", and "Token Endpoint" defined by OAuth 2.0
   [RFC6749], the terms "Claim Name", "Claim Value", and "JSON Web Token
   (JWT)" defined by JSON Web Token (JWT) [JWT].







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2.  Protected Resource Metadata

   Protected resources can have metadata describing their configuration.
   The following protected resource metadata values are used by this
   specification and are registered in the IANA "OAuth Protected
   Resource Metadata" registry established in Section 7.1:

   resource
      REQUIRED.  The protected resource's resource identifier, which is
      a URL that uses the "https" scheme and has no fragment components.
      This is the location where ".well-known" RFC 5785 [RFC5785]
      resources containing information about the protected resource are
      published.  Using these well-known resources is described in
      Section 3.

   authorization_servers
      OPTIONAL.  JSON array containing a list of OAuth authorization
      server issuer identifiers, as defined in
      [OAuth.AuthorizationMetadata], for authorization servers that can
      be used with this protected resource.  Protected resources MAY
      choose not to advertise some supported authorization servers even
      when this parameter is used.  In some use cases, the set of
      authorization servers will not be enumerable, in which case this
      metadata parameter would not be used.

   jwks_uri
      OPTIONAL.  URL of the protected resource's JWK Set [JWK] document.
      This contains keys belonging to the protected resource.  For
      instance, this JWK Set MAY contain encryption key(s) that are used
      to encrypt access tokens to the protected resource.  When both
      signing and encryption keys are made available, a "use" (public
      key use) parameter value is REQUIRED for all keys in the
      referenced JWK Set to indicate each key's intended usage.

   scopes_provided
      RECOMMENDED.  JSON array containing a list of the OAuth 2.0
      [RFC6749] "scope" values that are used in authorization requests
      to request access to this protected resource.  Protected resources
      MAY choose not to advertise some scope values provided even when
      this parameter is used.

   bearer_methods_supported
      OPTIONAL.  JSON array containing a list of the OAuth 2.0 Bearer
      Token [RFC6750] presentation methods that this protected resource
      supports.  Defined values are "["header", "fragment", "query"]",
      corresponding to Sections 2.1, 2.2, and 2.3 of RFC 6750.

   resource_signing_alg_values_supported



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      OPTIONAL.  JSON array containing a list of the JWS [JWS] signing
      algorithms ("alg" values) [JWA] supported by the protected
      resource for signed content.  The value "none" MAY be included.

   resource_encryption_alg_values_supported
      OPTIONAL.  JSON array containing a list of the JWE [JWE]
      encryption algorithms ("alg" values) [JWA] supported by the
      protected resource for encrypted content.

   resource_encryption_enc_values_supported
      OPTIONAL.  JSON array containing a list of the JWE encryption
      algorithms ("enc" values) [JWA] supported by the protected
      resource for encrypted content.

   resource_documentation
      OPTIONAL.  URL of a page containing human-readable information
      that developers might want or need to know when using the
      protected resource

   resource_policy_uri
      OPTIONAL.  URL that the protected resource provides to read about
      the protected resource's requirements on how the client can use
      the data provided by the protected resource

   resource_tos_uri
      OPTIONAL.  URL that the protected resource provides to read about
      the protected resource's terms of service

   Additional protected resource metadata parameters MAY also be used.

2.1.  Signed Protected Resource Metadata

   In addition to JSON elements, metadata values MAY also be provided as
   a "signed_metadata" value, which is a JSON Web Token (JWT) [JWT] that
   asserts metadata values about the protected resource as a bundle.  A
   set of claims that can be used in signed metadata are defined in
   Section 2.  The signed metadata MUST be digitally signed or MACed
   using JSON Web Signature (JWS) [JWS] and MUST contain an "iss"
   (issuer) claim denoting the party attesting to the claims in the
   signed metadata.  Consumers of the metadata MAY ignore the signed
   metadata if they do not support this feature.  If the consumer of the
   metadata supports signed metadata, metadata values conveyed in the
   signed metadata MUST take precedence over those conveyed using plain
   JSON elements.

   Signed metadata is included in the protected resource metadata JSON
   object using this OPTIONAL member:




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   signed_metadata
      A JWT containing metadata values about the protected resource as
      claims.  This is a string value consisting of the entire signed
      JWT.  A "signed_metadata" metadata value SHOULD NOT appear as a
      claim in the JWT.

3.  Obtaining Protected Resource Metadata

   Protected resources supporting metadata MUST make a JSON document
   containing metadata as specified in Section 2 available at a path
   formed by concatenating a well-known URI string such as "/.well-
   known/oauth-protected-resource" to the protected resource's resource
   identifier.  The syntax and semantics of ".well-known" are defined in
   RFC 5785 [RFC5785].  The well-known URI path suffix used MUST be
   registered in the IANA "Well-Known URIs" registry [IANA.well-known].

   Different applications utilizing OAuth protected resources in
   application-specific ways may define and register different well-
   known URI path suffixes used to publish protected resource metadata
   as used by those applications.  For instance, if the Example
   application uses an OAuth protected resource in an Example-specific
   way, and there are Example-specific metadata values that it needs to
   publish, then it might register and use the "example-resource-
   configuration" URI path suffix and publish the metadata document at
   the path formed by concatenating "/.well-known/example-resource-
   configuration" to the protected resource's resource identifier.

   An OAuth 2.0 application using this specification MUST specify what
   well-known URI string it will use for this purpose.  The same
   protected resource MAY choose to publish its metadata at multiple
   well-known locations relative to its resource identifier, for
   example, publishing metadata at both "/.well-known/example-resource-
   configuration" and "/.well-known/oauth-protected-resource".

3.1.  Protected Resource Metadata Request

   A protected resource metadata document MUST be queried using an HTTP
   "GET" request at the previously specified path.

   The consumer of the metadata would make the following request when
   the resource identifier is "https://resource.example.com" and the
   well-known URI path suffix is "oauth-protected-resource" to obtain
   the metadata, since the resource identifier contains no path
   component:

     GET /.well-known/oauth-protected-resource HTTP/1.1
     Host: resource.example.com




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   If the resource identifier value contains a path component, any
   terminating "/" MUST be removed before appending "/.well-known/" and
   the well-known URI path suffix.  The consumer of the metadata would
   make the following request when the resource identifier is
   "https://resource.example.com/resource1" and the well-known URI path
   suffix is "oauth-protected-resource" to obtain the metadata, since
   the resource identifier contains a path component:

     GET /resource1/.well-known/oauth-protected-resource HTTP/1.1
     Host: resource.example.com

   Using path components enables supporting multiple resources per host.
   This is required in some multi-tenant hosting configurations.  This
   use of ".well-known" is for supporting multiple resources per host;
   unlike its use in RFC 5785 [RFC5785], it does not provide general
   information about the host.

3.2.  Protected Resource Metadata Response

   The response is a set of claims about the protected resource's
   configuration.  A successful response MUST use the 200 OK HTTP status
   code and return a JSON object using the "application/json" content
   type that contains a set of claims as its members that are a subset
   of the metadata values defined in Section 2.  Other claims MAY also
   be returned.

   Claims that return multiple values are represented as JSON arrays.
   Claims with zero elements MUST be omitted from the response.

   An error response uses the applicable HTTP status code value.

   The following is a non-normative example response:

     HTTP/1.1 200 OK
     Content-Type: application/json

     {
      "resource":
        "https://resource.example.com",
      "authorization_servers":
        ["https://as1.example.com",
         "https://as2.example.net"],
      "bearer_methods_supported":
        ["header", "body"],
      "resource_documentation":
        "http://resource.example.com/resource_documentation.html"
     }




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3.3.  Protected Resource Metadata Validation

   The "resource" value returned MUST be identical to the protected
   resource's resource identifier value that was concatenated with the
   well-known URI path suffix to create the URL used to retrieve the
   metadata.  If these values are not identical, the data contained in
   the response MUST NOT be used.

4.  Authorization Server Metadata

   To support use cases in which the set of legitimate protected
   resources to use with the authorization server is fixed and
   enumerable, this specification defines the "protected_resources"
   metadata value, which enables explicitly listing them.  Note that if
   the set of legitimate authorization servers to use with a protected
   resource is also fixed and enumerable, lists in the authorization
   server metadata and protected resource metadata should be cross-
   checked against one another for consistency when these lists are used
   by the application profile.

   The following authorization server metadata value is defined by this
   specification and is registered in the IANA "OAuth Authorization
   Server Metadata" registry established in OAuth 2.0 Authorization
   Server Metadata [OAuth.AuthorizationMetadata].

   protected_resources
      OPTIONAL.  JSON array containing a list of resource identifiers
      for OAuth protected resources for protected resources that can be
      used with this authorization server.  Authorization servers MAY
      choose not to advertise some supported protected resources even
      when this parameter is used.  In some use cases, the set of
      protected resources will not be enumerable, in which case this
      metadata parameter would not be used.

5.  String Operations

   Processing some OAuth 2.0 messages requires comparing values in the
   messages to known values.  For example, the member names in the
   metadata response might be compared to specific member names such as
   "resource".  Comparing Unicode [UNICODE] strings, however, has
   significant security implications.

   Therefore, comparisons between JSON strings and other Unicode strings
   MUST be performed as specified below:

   1.  Remove any JSON applied escaping to produce an array of Unicode
       code points.




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   2.  Unicode Normalization [USA15] MUST NOT be applied at any point to
       either the JSON string or to the string it is to be compared
       against.

   3.  Comparisons between the two strings MUST be performed as a
       Unicode code point to code point equality comparison.

6.  Security Considerations

6.1.  TLS Requirements

   Implementations MUST support TLS.  Which version(s) ought to be
   implemented will vary over time, and depend on the widespread
   deployment and known security vulnerabilities at the time of
   implementation.  The protected resource MUST support TLS version 1.2
   [RFC5246] and MAY support additional transport-layer security
   mechanisms meeting its security requirements.  When using TLS, the
   client MUST perform a TLS/SSL server certificate check, per RFC 6125
   [RFC6125].  Implementation security considerations can be found in
   Recommendations for Secure Use of TLS and DTLS [BCP195].

   To protect against information disclosure and tampering,
   confidentiality protection MUST be applied using TLS with a
   ciphersuite that provides confidentiality and integrity protection.

6.2.  Impersonation Attacks

   TLS certificate checking MUST be performed by the client, as
   described in Section 6.1, when making a protected resource metadata
   request.  Checking that the server certificate is valid for the
   resource identifier URL prevents man-in-middle and DNS-based attacks.
   These attacks could cause a client to be tricked into using an
   attacker's resource server, which would enable impersonation of the
   legitimate protected resource.  If an attacker can accomplish this,
   they can access the resources that the affected client has access to
   using the protected resource that they are impersonating.

   An attacker may also attempt to impersonate a protected resource by
   publishing a metadata document that contains a "resource" claim using
   the resource identifier URL of the protected resource being
   impersonated, but containing information of the attacker's choosing.
   This would enable it to impersonate that protected resource, if
   accepted by the client.  To prevent this, the client MUST ensure that
   the resource identifier URL it is using as the prefix for the
   metadata request exactly matches the value of the "resource" metadata
   value in the protected resource metadata document received by the
   client.




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6.3.  Publishing Metadata in a Standard Format

   Publishing information about the protected resource in a standard
   format makes it easier for both legitimate clients and attackers to
   use the protected resource.  Whether a protected resource publishes
   its metadata in an ad-hoc manner or in the standard format defined by
   this specification, the same defenses against attacks that might be
   mounted that use this information should be applied.

6.4.  Authorization Servers

   Secure determination of appropriate authorization servers to use with
   a protected resource for all use cases is out of scope of this
   specification.  This specification assumes that the client has a
   means of determining appropriate authorization servers to use with a
   protected resource and that the client is using the correct metadata
   for each protected resource.  Implementers need to be aware that if
   an inappropriate authorization server is used by the client, that an
   attacker may be able to act as a man-in-the-middle proxy to a valid
   authorization server without it being detected by the authorization
   server or the client.

   The ways to determine the appropriate authorization servers to use
   with a protected resource are in general, application-dependent.  For
   instance, some protected resources are used with a fixed
   authorization server or set of authorization servers, the locations
   of which may be well known, or which could be published as metadata
   values by the protected resource.  In other cases, the set of
   authorization servers that can be used with a protected resource can
   by dynamically changed by administrative actions or by changes to the
   set of authorization servers adhering to a trust framework.  Many
   other means of determining appropriate associations between protected
   resources and authorization servers are also possible.

   To support use cases in which the set of legitimate authorization
   servers to use with the protected resource is fixed and enumerable,
   this specification defines the "authorization_servers" metadata
   value, which enables explicitly listing them.  Note that if the set
   of legitimate protected resources to use with an authorization server
   is also fixed and enumerable, lists in the protected resource
   metadata and authorization server metadata should be cross-checked
   against one another for consistency when these lists are used by the
   application profile.








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7.  IANA Considerations

   The following registration procedure is used for the registry
   established by this specification.

   Values are registered on a Specification Required [RFC5226] basis
   after a two-week review period on the oauth-ext-review@ietf.org
   mailing list, on the advice of one or more Designated Experts.
   However, to allow for the allocation of values prior to publication,
   the Designated Experts may approve registration once they are
   satisfied that such a specification will be published.

   Registration requests sent to the mailing list for review should use
   an appropriate subject (e.g., "Request to register OAuth Protected
   Resource Metadata: example").

   Within the review period, the Designated Experts will either approve
   or deny the registration request, communicating this decision to the
   review list and IANA.  Denials should include an explanation and, if
   applicable, suggestions as to how to make the request successful.
   Registration requests that are undetermined for a period longer than
   21 days can be brought to the IESG's attention (using the
   iesg@ietf.org mailing list) for resolution.

   Criteria that should be applied by the Designated Experts includes
   determining whether the proposed registration duplicates existing
   functionality, determining whether it is likely to be of general
   applicability or whether it is useful only for a single application,
   and whether the registration makes sense.

   IANA must only accept registry updates from the Designated Experts
   and should direct all requests for registration to the review mailing
   list.

   It is suggested that multiple Designated Experts be appointed who are
   able to represent the perspectives of different applications using
   this specification, in order to enable broadly-informed review of
   registration decisions.  In cases where a registration decision could
   be perceived as creating a conflict of interest for a particular
   Expert, that Expert should defer to the judgment of the other
   Experts.

7.1.  OAuth Protected Resource Metadata Registry

   This specification establishes the IANA "OAuth Protected Resource
   Metadata" registry for OAuth 2.0 protected resource metadata names.
   The registry records the protected resource metadata member and a
   reference to the specification that defines it.



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7.1.1.  Registration Template

   Metadata Name:
      The name requested (e.g., "resource").  This name is case-
      sensitive.  Names may not match other registered names in a case-
      insensitive manner unless the Designated Experts state that there
      is a compelling reason to allow an exception.

   Metadata Description:
      Brief description of the metadata (e.g., "Resource identifier
      URL").

   Change Controller:
      For Standards Track RFCs, list the "IESG".  For others, give the
      name of the responsible party.  Other details (e.g., postal
      address, email address, home page URI) may also be included.

   Specification Document(s):
      Reference to the document or documents that specify the parameter,
      preferably including URIs that can be used to retrieve copies of
      the documents.  An indication of the relevant sections may also be
      included but is not required.

7.1.2.  Initial Registry Contents

   o  Metadata Name: "resource"
   o  Metadata Description: Protected resource's resource identifier URL
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "authorization_servers"
   o  Metadata Description: JSON array containing a list of OAuth
      authorization server issuer identifiers
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "jwks_uri"
   o  Metadata Description: URL of the protected resource's JWK Set
      document
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "scopes_provided"
   o  Metadata Description: JSON array containing a list of the OAuth
      2.0 "scope" values that are used in authorization requests to
      request access this protected resource
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]



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   o  Metadata Name: "bearer_methods_supported"
   o  Metadata Description: JSON array containing a list of the OAuth
      2.0 Bearer Token presentation methods that this protected resource
      supports
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_signing_alg_values_supported"
   o  Metadata Description: JSON array containing a list of the JWS
      signing algorithms ("alg" values) supported by the protected
      resource for signed content
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_encryption_alg_values_supported"
   o  Metadata Description: JSON array containing a list of the JWE
      encryption algorithms ("alg" values) supported by the protected
      resource for encrypted content
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_encryption_enc_values_supported"
   o  Metadata Description: JSON array containing a list of the JWE
      encryption algorithms ("enc" values) supported by the protected
      resource for encrypted content
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_documentation"
   o  Metadata Description: URL of a page containing human-readable
      information that developers might want or need to know when using
      the protected resource
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_policy_uri"
   o  Metadata Description: URL that the protected resource provides to
      read about the protected resource's requirements on how the client
      can use the data provided by the protected resource
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]

   o  Metadata Name: "resource_tos_uri"
   o  Metadata Description: URL that the protected resource provides to
      read about the protected resource's terms of service
   o  Change Controller: IESG
   o  Specification Document(s): Section 2 of [[ this specification ]]




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7.2.  OAuth Authorization Server Metadata Registry

   The following authorization server metadata value is registered in
   the IANA "OAuth Authorization Server Metadata" registry established
   in OAuth 2.0 Authorization Server Metadata
   [OAuth.AuthorizationMetadata].

7.2.1.  Registry Contents

   o  Metadata Name: "protected_resources"
   o  Metadata Description: JSON array containing a list of resource
      identifiers for OAuth protected resources
   o  Change Controller: IESG
   o  Specification Document(s): Section 4 of [[ this specification ]]

7.3.  Well-Known URI Registry

   This specification registers the well-known URI defined in Section 3
   in the IANA "Well-Known URIs" registry [IANA.well-known] established
   by RFC 5785 [RFC5785].

7.3.1.  Registry Contents

   o  URI suffix: "oauth-protected-resource"
   o  Change controller: IESG
   o  Specification document: Section 3 of [[ this specification ]]
   o  Related information: (none)

8.  References

8.1.  Normative References

   [BCP195]   Sheffer, Y., Holz, R., and P. Saint-Andre,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
              2015, <http://www.rfc-editor.org/info/bcp195>.

   [JWA]      Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
              DOI 10.17487/RFC7518, May 2015,
              <http://tools.ietf.org/html/rfc7518>.

   [JWE]      Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)",
              RFC 7516, DOI 10.17487/RFC7516, May 2015,
              <http://tools.ietf.org/html/rfc7516>.






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   [JWK]      Jones, M., "JSON Web Key (JWK)", RFC 7517,
              DOI 10.17487/RFC7517, May 2015,
              <http://tools.ietf.org/html/rfc7517>.

   [JWS]      Jones, M., Bradley, J., and N. Sakimura, "JSON Web
              Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
              2015, <http://tools.ietf.org/html/rfc7515>.

   [JWT]      Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token
              (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015,
              <http://tools.ietf.org/html/rfc7519>.

   [OAuth.AuthorizationMetadata]
              Jones, M., Sakimura, N., and J. Bradley, "OAuth 2.0
              Authorization Server Metadata", draft-ietf-oauth-
              discovery-05 (work in progress), January 2017,
              <http://tools.ietf.org/html/
              draft-ietf-oauth-discovery-05>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <http://www.rfc-editor.org/info/rfc5226>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008,
              <http://www.rfc-editor.org/info/rfc5246>.

   [RFC5785]  Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
              Uniform Resource Identifiers (URIs)", RFC 5785,
              DOI 10.17487/RFC5785, April 2010,
              <http://www.rfc-editor.org/info/rfc5785>.

   [RFC6125]  Saint-Andre, P. and J. Hodges, "Representation and
              Verification of Domain-Based Application Service Identity
              within Internet Public Key Infrastructure Using X.509
              (PKIX) Certificates in the Context of Transport Layer
              Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
              2011, <http://www.rfc-editor.org/info/rfc6125>.






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   [RFC6749]  Hardt, D., Ed., "The OAuth 2.0 Authorization Framework",
              RFC 6749, DOI 10.17487/RFC6749, October 2012,
              <http://www.rfc-editor.org/info/rfc6749>.

   [RFC6750]  Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
              Framework: Bearer Token Usage", RFC 6750,
              DOI 10.17487/RFC6750, October 2012,
              <http://www.rfc-editor.org/info/rfc6750>.

   [RFC7033]  Jones, P., Salgueiro, G., Jones, M., and J. Smarr,
              "WebFinger", RFC 7033, DOI 10.17487/RFC7033, September
              2013, <http://www.rfc-editor.org/info/rfc7033>.

   [RFC7159]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
              2014, <http://www.rfc-editor.org/info/rfc7159>.

   [RFC7591]  Richer, J., Ed., Jones, M., Bradley, J., Machulak, M., and
              P. Hunt, "OAuth 2.0 Dynamic Client Registration Protocol",
              RFC 7591, DOI 10.17487/RFC7591, July 2015,
              <http://www.rfc-editor.org/info/rfc7591>.

   [UNICODE]  The Unicode Consortium, "The Unicode Standard",
              <http://www.unicode.org/versions/latest/>.

   [USA15]    Davis, M. and K. Whistler, "Unicode Normalization Forms",
              Unicode Standard Annex 15, June 2015,
              <http://www.unicode.org/reports/tr15/>.

8.2.  Informative References

   [I-D.ietf-oauth-mix-up-mitigation]
              Jones, M., Bradley, J., and N. Sakimura, "OAuth 2.0 Mix-Up
              Mitigation", draft-ietf-oauth-mix-up-mitigation-01 (work
              in progress), July 2016.

   [IANA.well-known]
              IANA, "Well-Known URIs",
              <http://www.iana.org/assignments/well-known-uris>.

   [OpenID.Discovery]
              Sakimura, N., Bradley, J., Jones, M., and E. Jay, "OpenID
              Connect Discovery 1.0", November 2014,
              <http://openid.net/specs/
              openid-connect-discovery-1_0.html>.






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Appendix A.  Acknowledgements

   Thanks to George Fletcher and Tony Nadalin for their input on the
   specification.

Appendix B.  Document History

   [[ to be removed by the RFC Editor before publication as an RFC ]]

   -01

   o  Moved the "protected_resources" authorization server metadata
      element here, removing it from draft-ietf-oauth-discovery.

   -00

   o  Created the initial version.  This draft reuses some text from
      draft-ietf-oauth-discovery-03.

Authors' Addresses

   Michael B. Jones
   Microsoft

   Email: mbj@microsoft.com
   URI:   http://self-issued.info/


   Phil Hunt
   Oracle

   Email: phil.hunt@yahoo.com



















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