OAuth Working Group                                     N. Sakimura, Ed.
Internet-Draft                                 Nomura Research Institute
Intended status: Standards Track                              J. Bradley
Expires: April 16, July 22, 2016                                     Ping Identity
                                                        October 14, 2015
                                                        January 19, 2016

                  OAuth 2.0 JWT Authorization Request
                       draft-ietf-oauth-jwsreq-06
                       draft-ietf-oauth-jwsreq-07

Abstract

   The authorization request in RFC6749 OAuth 2.0 [RFC6749] utilizes query
   parameter
   serialization. serialization, which means that parameters are encoded in
   the URI of the request.  This specification defines document introduces the ability to send
   request parameters in form of a JSON Web Token (JWT) instead, which
   allows the authorization request to be signed and encrypted.  using JWT
   serialization.  The request is sent by value through
   "request" parameter or by reference through "request_uri" parameter
   that points to the JWT, allowing the request to be optionally signed
   and encrypted. reference.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on April 16, July 22, 2016.

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   Copyright (c) 2015 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Request Object  . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Request Object URI  . . . . . . . . . . . . . . . . . . .   4   5
   3.  Request Object  . . . . . . . . . . . . . . . . . . . . . . .   4   5
   4.  Authorization Request . . . . . . . . . . . . . . . . . . . .   6   7
     4.1.  Passing a Request Object by Value . . . . . . . . . . . .   7   8
     4.2.  Passing a Request Object by Reference . . . . . . . . . .   8
       4.2.1.  URL Referencing the Request Object  . . . . . . . . .  10
       4.2.2.  Request using the "request_uri" Request Parameter . .  10
       4.2.3.  Authorization Server Fetches Request Object . . . . .  11
   5.  Validating JWT-Based Requests . . . . . . . . . . . . . . . .  11
     5.1.  Encrypted Request Object  . . . . . . . . . . . . . . . .  11
     5.2.  Signed Request Object . . . . . . . . . . . . . . . . . .  11
     5.3.  Request Parameter Assembly and Validation . . . . . . . .  12
   6.  Authorization Server Response . . . . . . . . . . . . . . . .  12
   7.  IANA  Considerations  . . . . . . . . . . . . . . . . . . . .  12
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  13
   10. Revision History  . . . . . . . . . . . . . . . . . . . . . .  13
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  14  15
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  14  15
     11.2.  Informative References . . . . . . . . . . . . . . . . .  15  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15  16

1.  Introduction

   The OAuth 2.0 specification [RFC 6749] defines the encoding of
   requests and responses and in case of the authorization request query
   parameter serialization has been chosen.  For example, the parameters
   'response_type', 'client_id', 'state', and 'redirect_uri' are encoded
   in the URI of the request:

GET /authorize?response_type=code&client_id=s6BhdRkqt3&state=xyz &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb HTTP/1.1
Host: server.example.com

   The encoding in the URI does not allow application layer security
   with confidentiality and integrity protection to be used.  While TLS
   is used to offer communication security between the client and the
   resource server, TLS sessions are often terminated prematurely at
   some middlebox (such as a load balancer).  The use of application
   layer security additionally allows requests to be prepared by a third
   party so that a client application cannot request more permissions
   than previously agreed.  This offers an additional degree of privacy
   protection.

   Further, the request by reference allows to reduce the over-the-wire
   overhead.

   There are other potential formats that could be used for this purpose
   instead of JWT.  The JWT was chosen because of

   1.  its close relationship with JSON, which is used as OAuth's
       response format;

   2.  its developer friendliness due to its textaual nature;

   3.  its relative compactness compared to XML;

   4.  its development status that it is an RFC and so is its associated
       signing and encryption methods as [RFC7515] and [RFC7516].

   The parameters "request" and "request_uri" are introduced as
   additional authorization request parameters for the OAuth 2.0
   [RFC6749] flows.  The "request" parameter is a JSON Web Token (JWT)
   [RFC7519] whose JWT Claims Set holds the JSON encoded OAuth 2.0
   authorization request parameters.  The JWT [RFC7519] can be passed to
   the authorization endpoint by reference, in which case the parameter
   "request_uri" is used instead of the "request".

   Using JWT [RFC7519] as the request encoding instead of query
   parameters has several advantages:

   1.  The request can be signed so that an integrity check can be
       implemented.  If a suitable algorithm is used for the signing,
       then it will provide verification of the client making the
       request.

   2.  The request may be encrypted so that end-to-end confidentiality
       may be obtained even if in the case TLS connection is terminated
       at a gateway or a similar device.

   3.  The request may be signed by a third party attesting that the
       authorization request is compliant to certain policy.  For
       example, a request can be pre-examined by a third party that all
       the personal data requested is strictly necessary to perform the
       process that the end-user asked for, and statically signed by
       that third party.  The client would then send the request along
       with dynamic parameters such as state.  The authorization server
       then examines the signature and show shows the conformance status to
       the end-user, who would have some assurance as to the legitimacy
       of the request when authorizing it.  In some cases, it may even
       be desirable to skip the authorization dialogue under such
       circumstances.

   There are a few cases that request by reference are useful such as:

   1.  When it is detected that desirable to reduced the User Agent does not support long
       URLs: Some extensions size of transmitted request.
       Since we are using application layer security, it may extend
       substantially increase the URL.  For example, size of the
       client might want to send a request particulary in the
       case of using public key with the request. cryptography.

   2.  Static signature: The client can make a signed Request Object and
       put it at a place that the Authorization Server can access.  This
       may just be done by a client utility or other process, so that
       the private key does not have to reside on the client,
       simplifying programming.  Downside of it is that the signed
       portion just become a token.

   3.  When the server wants the requests to be cacheable: The
       request_uri may include a SHA-256 hash of the file, as defined in
       FIPS180-2 [FIPS180-2], contents of the
       resources referenced by the Request URI.  With this, the server
       knows if the file resource has changed without fetching it, so it does
       not have to re-fetch a the same file, content, which is a win as well.

   4.  When the client wants to simplify the implementation without
       compromising the security.  If the request parameters go through
       the browser, they may be tampered in the browser even if TLS was
       used.
       This implies we need to have signature on the request as
       well.  However, if HTTPS "request_uri" was used, it is not going
       to be tampered, thus we now do not have to sign the request.
       This simplifies the implementation. explained in Section 4.2.

   This capability is in use by OpenID Connect [OpenID.Core].

1.1.  Requirements Language

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

2.  Terminology

   For the purposes of this specification, the following terms and
   definitions apply.

2.1.  Request Object

   JWT [RFC7519] that holds an OAuth 2.0 authorization request as JWT
   Claims Set

2.2.  Request Object URI

   Absolute URI from which the Request Object (Section 2.1) can be
   obtained

3.  Request Object

   A Request Object (Section 2.1) is used to provide authorization
   request parameters for an OAuth 2.0 authorization request.  It
   contains OAuth 2.0 [RFC6749] authorization request parameters
   including extension parameters.  It is a JSON Web Signature (JWS)
   [RFC7515] signed JWT [RFC7519] .  The parameters are represented as
   the JWT claims.  Parameter names and string values MUST be included
   as JSON strings.  Numerical values MUST be included as JSON numbers.
   It MAY include any extension parameters.  This JSON [RFC7159]
   constitutes the JWT [RFC7519] Claims Set. Set [RFC7519].  The Request Object MAY be signed JWS Claims Set is then
   signed, encrypted, or be an Unsecured JWS.  When it signed and encrypted.

   To sign, JSON Web Signature (JWS) [RFC7515] is
   an unsecured JWS, this used.  The result is indicated by use of the "none" algorithm
   JWA [RFC7518] in the a
   JWS header. signed JWT [RFC7519].  If signed, the Authorization Request
   Object SHOULD contain the Claims "iss" (issuer) and "aud" (audience)
   as members, with their semantics being the same as defined in the JWT
   [RFC7519] specification.

   The Request Object MAY also be encrypted using

   To encrypt, JWE [RFC7516] and MAY
   be encrypted without is used.  Note that JWE is always integrity
   protected, so if only integrity protection is desired, JWS signature
   is not needed.

   It can also being signed.  If both signing and
   encryption are performed, be signed then encrypted.  This is sometimes desired to
   reduced the repudiation risk from the point of view of the receiver.
   In this case, it MUST be signed then encrypted, with the result being
   a Nested JWT, as defined in JWT [RFC7519].

   The Authorization Request Object MAY alternatively may be sent by
   reference using the "request_uri" parameter. value as described in
   Section 4.1 or by reference as described in Section 4.2.

   REQUIRED OAuth 2.0 Authorization Request parameters that are not
   included in the Request Object MUST be sent as a query parameter. parameters.  If
   a required parameter is not present in neither missing from both the query parameter
   nor parameters and
   the Request Object, it forms a malformed request. the request is malformed.

   "request" and "request_uri" parameters MUST NOT be included in
   Request Objects.

   If the parameter exists in both the query string and the
   Authorization Request Object, the values in the Request Object takes take
   precedence.  This means that if it intends to use a cached request
   object, it cannot include such parameters like such as "state" that is are
   expected to differ in every request.  It is fine to include them in
   the request object if it is going to be prepared afresh every time.

   The following is a non-normative example of the Claims in a Request
   Object before base64url encoding and signing.  Note that it includes
   extension variables such as "nonce", "userinfo", "nonce" and "id_token". "max_age".

     {
      "iss": "s6BhdRkqt3",
      "aud": "https://server.example.com",
      "response_type": "code id_token",
      "client_id": "s6BhdRkqt3",
      "redirect_uri": "https://client.example.org/cb",
      "scope": "openid",
      "state": "af0ifjsldkj",
      "nonce": "n-0S6_WzA2Mj",
      "max_age": 86400,
      "claims":
       {
        "userinfo":
         {
          "given_name": {"essential": true},
          "nickname": null,
          "email": {"essential": true},
          "email_verified": {"essential": true},
          "picture": null
         },
        "id_token":
         {
          "gender": null,
          "birthdate": {"essential": true},
          "acr": {"values": ["urn:mace:incommon:iap:silver"]}
         }
       } 86400
     }

   Signing it with the "RS256" algorithm results in this Request Object
   value (with line wraps within values for display purposes only):

     eyJhbGciOiJSUzI1NiIsImtpZCI6ImsyYmRjIn0.ew0KICJpc3MiOiAiczZCaGRSa3
     F0MyIsDQogImF1ZCI6ICJodHRwczovL3NlcnZlci5leGFtcGxlLmNvbSIsDQogInJl
     c3BvbnNlX3R5cGUiOiAiY29kZSBpZF90b2tlbiIsDQogImNsaWVudF9pZCI6ICJzNk
     JoZFJrcXQzIiwNCiAicmVkaXJlY3RfdXJpIjogImh0dHBzOi8vY2xpZW50LmV4YW1w
     bGUub3JnL2NiIiwNCiAic2NvcGUiOiAib3BlbmlkIiwNCiAic3RhdGUiOiAiYWYwaW
     Zqc2xka2oiLA0KICJub25jZSI6ICJuLTBTNl9XekEyTWoiLA0KICJtYXhfYWdlIjog
     ODY0MDAsDQogImNsYWltcyI6IA0KICB7DQogICAidXNlcmluZm8iOiANCiAgICB7DQ
     ogICAgICJnaXZlbl9uYW1lIjogeyJlc3NlbnRpYWwiOiB0cnVlfSwNCiAgICAgIm5p
     Y2tuYW1lIjogbnVsbCwNCiAgICAgImVtYWlsIjogeyJlc3NlbnRpYWwiOiB0cnVlfS
     wNCiAgICAgImVtYWlsX3ZlcmlmaWVkIjogeyJlc3NlbnRpYWwiOiB0cnVlfSwNCiAg
     ICAgInBpY3R1cmUiOiBudWxsDQogICAgfSwNCiAgICJpZF90b2tlbiI6IA0KICAgIH
     sNCiAgICAgImdlbmRlciI6IG51bGwsDQogICAgICJiaXJ0aGRhdGUiOiB7ImVzc2Vu
     dGlhbCI6IHRydWV9LA0KICAgICAiYWNyIjogeyJ2YWx1ZXMiOiBbInVybjptYWNlOm
     luY29tbW9uOmlhcDpzaWx2ZXIiXX0NCiAgICB9DQogIH0NCn0.nwwnNsk1-Zkbmnvs
     F6zTHm8CHERFMGQPhos-EJcaH4Hh-sMgk8ePrGhw_trPYs8KQxsn6R9Emo_wHwajyF
     KzuMXZFSZ3p6Mb8dkxtVyjoy2GIzvuJT_u7PkY2t8QU9hjBcHs68PkgjDVTrG1uRTx
     0GxFbuPbj96tVuj11pTnmFCUR6IEOXKYr7iGOCRB3btfJhM0_AKQUfqKnRlrRscc8K
     ol-cSLWoYE9l5QqholImzjT_cMnNIznW9E7CDyWXTsO70xnB4SkG6pXfLSjLLlxmPG
     iyon_-Te111V8uE83IlzCYIb_NMXvtTIVc1jpspnTSD7xMbpL-2QgwUsAlMGzw

   The following RSA public key, represented in JWK format, can be used
   to validate the Request Object signature in this and subsequent
   Request Object examples (with line wraps within values for display
   purposes only):

     {
      "kty":"RSA",
      "kid":"k2bdc",
      "n":"y9Lqv4fCp6Ei-u2-ZCKq83YvbFEk6JMs_pSj76eMkddWRuWX2aBKGHAtKlE5P
           7_vn__PCKZWePt3vGkB6ePgzAFu08NmKemwE5bQI0e6kIChtt_6KzT5OaaXDF
           I6qCLJmk51Cc4VYFaxgqevMncYrzaW_50mZ1yGSFIQzLYP8bijAHGVjdEFgZa
           ZEN9lsn_GdWLaJpHrB3ROlS50E45wxrlg9xMncVb8qDPuXZarvghLL0HzOuYR
           adBJVoWZowDNTpKpk2RklZ7QaBO7XDv3uR7s_sf2g-bAjSYxYUGsqkNA9b3xV
           W53am_UZZ3tZbFTIh557JICWKHlWj5uzeJXaw",
      "e":"AQAB"
     }

4.  Authorization Request

   The client constructs the authorization request URI by adding one of
   the following parameters but not both to the query component of the
   authorization endpoint URI using the "application/x-www-form-urlencoded" "application/x-www-form-
   urlencoded" format:

   request  REQUIRED unless "request_uri" is specified.  The Request Object (Section 3) that holds authorization
      request parameters stated in the section 4 of OAuth 2.0 [RFC6749].

   request_uri  REQUIRED unless "request" is specified.  The absolute URL that points to the Request Object
      (Section 3) that holds authorization request parameters stated in
      the section 4 of OAuth 2.0 [RFC6749].

   state  RECOMMENDED.  OAuth 2.0 [RFC6749] state.

   The client directs the resource owner to the constructed URI using an
   HTTP redirection response, or by other means available to it via the
   user-agent.

   For example, the client directs the end-user's user-agent to make the
   following HTTPS request (line breaks are for display purposes only): request:

   GET /authorize?request_uri=https%3A%2F%2Fclient%2Eexample%2Ecom%2Fcb /authz?request=eyJhbG..AlMGzw HTTP/1.1
   Host: server.example.com

   The value for the request parameter is abbreviated for brevity.

   The authorization request object MAY be signed AND/OR encrypted.

   When the "request" parameter Request Object is used, the OAuth 2.0 request parameter
   values contained in the JWT supersede those passed using the OAuth
   2.0 request syntax.  However, parameters MAY also be passed using the
   OAuth 2.0 request syntax even when a Request Object is used; this
   would typically be done to enable a cached, pre-signed (and possibly
   pre-encrypted) Request Object value to be used containing the fixed
   request parameters, while parameters that can vary with each request,
   such as state and nonce, are passed as OAuth 2.0 parameters.

4.1.  Passing a Request Object by Value

   The Client sends the Authorization Request as a Request Object to the
   Authorization Endpoint as the "request" parameter value.

   The following is a non-normative example of an Authorization Request
   using the "request" parameter (with line wraps within values for
   display purposes only):

     https://server.example.com/authorize?
       response_type=code%20id_token
       &client_id=s6BhdRkqt3
       &redirect_uri=https%3A%2F%2Fclient.example.org%2Fcb
       &scope=openid
       &state=af0ifjsldkj
       &nonce=n-0S6_WzA2Mj
       &request=eyJhbGciOiJSUzI1NiIsImtpZCI6ImsyYmRjIn0.ew0KICJpc3MiOiA
       iczZCaGRSa3F0MyIsDQogImF1ZCI6ICJodHRwczovL3NlcnZlci5leGFtcGxlLmN
       vbSIsDQogInJlc3BvbnNlX3R5cGUiOiAiY29kZSBpZF90b2tlbiIsDQogImNsaWV
       udF9pZCI6ICJzNkJoZFJrcXQzIiwNCiAicmVkaXJlY3RfdXJpIjogImh0dHBzOi8
       vY2xpZW50LmV4YW1wbGUub3JnL2NiIiwNCiAic2NvcGUiOiAib3BlbmlkIiwNCiA
       ic3RhdGUiOiAiYWYwaWZqc2xka2oiLA0KICJub25jZSI6ICJuLTBTNl9XekEyTWo
       iLA0KICJtYXhfYWdlIjogODY0MDAsDQogImNsYWltcyI6IA0KICB7DQogICAidXN
       lcmluZm8iOiANCiAgICB7DQogICAgICJnaXZlbl9uYW1lIjogeyJlc3NlbnRpYWw
       iOiB0cnVlfSwNCiAgICAgIm5pY2tuYW1lIjogbnVsbCwNCiAgICAgImVtYWlsIjo
       geyJlc3NlbnRpYWwiOiB0cnVlfSwNCiAgICAgImVtYWlsX3ZlcmlmaWVkIjogeyJ
       lc3NlbnRpYWwiOiB0cnVlfSwNCiAgICAgInBpY3R1cmUiOiBudWxsDQogICAgfSw
       NCiAgICJpZF90b2tlbiI6IA0KICAgIHsNCiAgICAgImdlbmRlciI6IG51bGwsDQo
       gICAgICJiaXJ0aGRhdGUiOiB7ImVzc2VudGlhbCI6IHRydWV9LA0KICAgICAiYWN
       yIjogeyJ2YWx1ZXMiOiBbInVybjptYWNlOmluY29tbW9uOmlhcDpzaWx2ZXIiXX0
       NCiAgICB9DQogIH0NCn0.nwwnNsk1-ZkbmnvsF6zTHm8CHERFMGQPhos-EJcaH4H
       h-sMgk8ePrGhw_trPYs8KQxsn6R9Emo_wHwajyFKzuMXZFSZ3p6Mb8dkxtVyjoy2
       GIzvuJT_u7PkY2t8QU9hjBcHs68PkgjDVTrG1uRTx0GxFbuPbj96tVuj11pTnmFC
       UR6IEOXKYr7iGOCRB3btfJhM0_AKQUfqKnRlrRscc8Kol-cSLWoYE9l5QqholImz
       jT_cMnNIznW9E7CDyWXTsO70xnB4SkG6pXfLSjLLlxmPGiyon_-Te111V8uE83Il
       zCYIb_NMXvtTIVc1jpspnTSD7xMbpL-2QgwUsAlMGzw

4.2.  Passing a Request Object by Reference

   The "request_uri" Authorization Request parameter enables OAuth
   authorization requests to be passed by reference, rather than by
   value.  This parameter is used identically to the "request"
   parameter, other than that the Request Object value is retrieved from
   the resource at the specified URL, rather than passed by value.

   When the "request_uri" parameter is used, the OAuth 2.0 authorization
   request parameter values contained in the referenced JWT supersede
   those passed using the OAuth 2.0 request syntax.  However, parameters
   MAY also be passed using the OAuth 2.0 request syntax even when a
   "request_uri" is used; this would typically be done to enable a
   cached, pre-signed (and possibly pre-encrypted) Request Object value
   to be used containing the fixed request parameters, while parameters
   that can vary with each request, such as "state" and "nonce", are
   passed as OAuth 2.0 parameters.

   Servers MAY cache the contents of the resources referenced by Request
   URIs.  If the contents of the referenced resource could ever change,
   the URI SHOULD include the base64url encoded SHA-256 hash as defined
   in FIPS180-2 [FIPS180-2] of the referenced resource contents as the
   fragment component of the URI.  If the fragment value used for a URI
   changes, that signals the server that any cached value for that URI
   with the old fragment value is no longer valid.

   The entire Request URI MUST NOT exceed 512 ASCII characters.  There
   are three reasons for this restriction.

   1.  Many WAP / feature phones do not accept large payloads.  The
       restriction are typically either 512 or 1024 ASCII characters.

   2.  The maximum URL length supported by older versions of Internet
       Explorer is 2083 ASCII characters.

   3.  On a slow connection such as 2G mobile connection, a large URL
       would cause the slow response and using such is not advisable
       from the user experience point of view.

   The contents of the resource referenced by the URL MUST be a Request
   Object.  The scheme used in the "request_uri" value MUST be "https",
   unless the target Request Object is signed in a way that is
   verifiable by the Authorization Server.  The "request_uri" value MUST
   be reachable by the Authorization Server, and SHOULD be reachable by
   the Client.

   The following is a non-normative example of the contents of a Request
   Object resource that can be referenced by a "request_uri" (with line
   wraps within values for display purposes only):

     eyJhbGciOiJSUzI1NiIsImtpZCI6ImsyYmRjIn0.ew0KICJpc3MiOiAiczZCaGRSa3
     F0MyIsDQogImF1ZCI6ICJodHRwczovL3NlcnZlci5leGFtcGxlLmNvbSIsDQogInJl
     c3BvbnNlX3R5cGUiOiAiY29kZSBpZF90b2tlbiIsDQogImNsaWVudF9pZCI6ICJzNk
     JoZFJrcXQzIiwNCiAicmVkaXJlY3RfdXJpIjogImh0dHBzOi8vY2xpZW50LmV4YW1w
     bGUub3JnL2NiIiwNCiAic2NvcGUiOiAib3BlbmlkIiwNCiAic3RhdGUiOiAiYWYwaW
     Zqc2xka2oiLA0KICJub25jZSI6ICJuLTBTNl9XekEyTWoiLA0KICJtYXhfYWdlIjog
     ODY0MDAsDQogImNsYWltcyI6IA0KICB7DQogICAidXNlcmluZm8iOiANCiAgICB7DQ
     ogICAgICJnaXZlbl9uYW1lIjogeyJlc3NlbnRpYWwiOiB0cnVlfSwNCiAgICAgIm5p
     Y2tuYW1lIjogbnVsbCwNCiAgICAgImVtYWlsIjogeyJlc3NlbnRpYWwiOiB0cnVlfS
     wNCiAgICAgImVtYWlsX3ZlcmlmaWVkIjogeyJlc3NlbnRpYWwiOiB0cnVlfSwNCiAg
     ICAgInBpY3R1cmUiOiBudWxsDQogICAgfSwNCiAgICJpZF90b2tlbiI6IA0KICAgIH
     sNCiAgICAgImdlbmRlciI6IG51bGwsDQogICAgICJiaXJ0aGRhdGUiOiB7ImVzc2Vu
     dGlhbCI6IHRydWV9LA0KICAgICAiYWNyIjogeyJ2YWx1ZXMiOiBbInVybjptYWNlOm
     luY29tbW9uOmlhcDpzaWx2ZXIiXX0NCiAgICB9DQogIH0NCn0.nwwnNsk1-Zkbmnvs
     F6zTHm8CHERFMGQPhos-EJcaH4Hh-sMgk8ePrGhw_trPYs8KQxsn6R9Emo_wHwajyF
     KzuMXZFSZ3p6Mb8dkxtVyjoy2GIzvuJT_u7PkY2t8QU9hjBcHs68PkgjDVTrG1uRTx
     0GxFbuPbj96tVuj11pTnmFCUR6IEOXKYr7iGOCRB3btfJhM0_AKQUfqKnRlrRscc8K
     ol-cSLWoYE9l5QqholImzjT_cMnNIznW9E7CDyWXTsO70xnB4SkG6pXfLSjLLlxmPG
     iyon_-Te111V8uE83IlzCYIb_NMXvtTIVc1jpspnTSD7xMbpL-2QgwUsAlMGzw

4.2.1.  URL Referencing the Request Object

   The Client stores the Request Object resource either locally or
   remotely at a URL the Authorization Server can access.  This URL is
   the Request URI, "request_uri".

   If

   It is possible for the Request Object includes requested to include values for Claims, it MUST
   NOT that is to be
   revealed only to anybody but the Authorization Server.  As such, the
   "request_uri" MUST have appropriate entropy for its lifetime.  It is
   RECOMMENDED that it be removed if it is known that it will not be
   used again or after a reasonable timeout unless access control
   measures are taken.

   The following is a non-normative example of a Request URI value (with
   line wraps within values for display purposes only):

     https://client.example.org/request.jwt#
       GkurKxf5T0Y-mnPFCHqWOMiZi4VS138cQO_V7PZHAdM

4.2.2.  Request using the "request_uri" Request Parameter

   The Client sends the Authorization Request to the Authorization
   Endpoint.

   The following is a non-normative example of an Authorization Request
   using the "request_uri" parameter (with line wraps within values for
   display purposes only):

     https://server.example.com/authorize?
       response_type=code%20id_token
       &client_id=s6BhdRkqt3
       &request_uri=https%3A%2F%2Fclient.example.org%2Frequest.jwt
       %23GkurKxf5T0Y-mnPFCHqWOMiZi4VS138cQO_V7PZHAdM
       &state=af0ifjsldkj

4.2.3.  Authorization Server Fetches Request Object

   Upon receipt of the Request, the Authorization Server MUST send an
   HTTP "GET" request to the "request_uri" to retrieve the referenced
   Request Object, unless it is already cached, and parse it to recreate
   the Authorization Request parameters.

   Note that the client SHOULD use a unique URI for each request
   utilizing distinct parameters, or otherwise prevent the Authorization
   Server from caching the "request_uri".

   The following is a non-normative example of this fetch process:

     GET /request.jwt HTTP/1.1
     Host: client.example.org

5.  Validating JWT-Based Requests

5.1.  Encrypted Request Object

   The Authorization Server MUST decrypt the JWT in accordance with the
   JSON Web Encryption [RFC7516] specification.  The  If the result MAY be
   either is a
   signed or unsigned (plaintext) Request Object.  In the
   former case, request object, signature validation MUST be performed as
   defined in Section 5.2. 5.2 as well.

   The Authorization Server MUST return an error if decryption fails.

5.2.  Signed Request Object

   To perform Signature Validation, the "alg" Header Parameter in the
   JOSE Header MUST match the value of the "request_object_signing_alg"
   set during Client Registration or a value that was pre-registered by
   other means. algorithm.
   The signature MUST be validated against the appropriate key for that
   "client_id" and algorithm.

   The Authorization Server MUST return an error if signature validation
   fails.

5.3.  Request Parameter Assembly and Validation

   The Authorization Server MUST assemble the set of Authorization
   Request parameters to be used from the Request Object value and the
   OAuth 2.0 Authorization Request parameters (minus the "request" or
   "request_uri" parameters).  If the same parameter exists both in the
   Request Object and the OAuth Authorization Request parameters, the
   parameter in the Request Object is used.  Using the assembled set of
   Authorization Request parameters, the Authorization Server then
   validates the request as specified in OAuth 2.0 [RFC6749].

6.  Authorization Server Response

   Authorization Server Response is created and sent to the client as in
   Section 4 of OAuth 2.0 [RFC6749] .

   In addition, this document defines uses these additional error values as
   follows: values:

   invalid_request_uri  The "request_uri" in the Authorization Request
      returns an error or contains invalid data.

   invalid_request_object  The request parameter contains an invalid
      Request Object.

   request_not_supported  The Authorization Server does not support the
      use of the "request" parameter.

   request_uri_not_supported  The Authorization Server does not support
      use of the "request_uri" parameter.

7.  IANA Considerations

   The request_object_signing_alg OAuth Dynamic Client Registration
   Metadata is pending registration

   This specification requests no actions by OpenID Connect Dynamic
   Registration specification. IANA.

8.  Security Considerations

   In addition to the all the security considerations discussed in OAuth
   2.0 [RFC6819], the following security considerations SHOULD be taken
   into account.

   When sending the authorization request object through "request"
   parameter, it SHOULD be signed with then considered appropriate
   algorithm using [RFC7515].  The "alg=none" SHOULD NOT be used in such
   a case.

   If the request object contains personally identifiable or sensitive
   information, the "request_uri" MUST be of one-time use and MUST have
   large enough entropy deemed necessary with applicable security
   policy.  For higher security requirement, using [RFC7516] is strongly
   recommended.

9.  Acknowledgements

   Follwoing people contributed to the creation of this document in
   OAuth WG.  (Affiliations at the time of the contribution is used.)

   Sergey Beryozkin, Brian Campbell (Ping Identity), Michael B.  Jones
   (Microsoft), Axel Nenker(DT), Sergey Beryozkin, Jim Manico, Axel Nenker(DT), (add yourself).

   Following people contributed to creating this document through the
   OpenID Connect 1.0 [OpenID.Core].

   Breno de Medeiros (Google), Hideki Nara (TACT),

   Brian Campbell (Ping Identity), George Fletcher (AOL), Ryo Itou
   (Yahoo!  Japan), George Fletcher (AOL), Justin Richer (MITRE), Edmund Jay (Illumila), Michael B.  Jones
   (Microsoft), Breno de Medeiros (Google), Hideki Nara (TACT), Justin
   Richer (MITRE), (add yourself).

   In addition following people contributed to this and previous
   versions through The OAuth Working Group.

   David Recordon (Facebook), Luke Shepard (Facebook),

   Dirk Balfanz (Google), James H.  Manger (Telstra), Marius Scurtescu (Google), John Panzer
   (Google), Dirk
   Balfanz David Recordon (Facebook), Marius Scurtescu (Google), Luke
   Shepard (Facebook), (add yourself).

10.  Revision History

   -07

   o  Changed the abbrev to OAuth JAR from oauth-jar.

   o  Clarified sig and enc methods.

   o  Better English.

   o  Removed claims from one of the example.

   o  Re-worded the URI construction.

   o  Changed the example to use request instead of request_uri.

   o  Clarified that Request Object parameters takes precedence
      regardless of request or request_uri parameters were used.

   o  Generalized the language in 4.2.1 to convey the intent more
      clearly.

   o  Changed "Server" to "Authorization Server" as a clarification.

   o  Stopped talking about request_object_signing_alg.

   o  IANA considerations now reflect the current status.

   o  Added Brian Campbell to the contributers list.  Made the lists
      alphabetic order based on the last names.  Clarified that the
      affiliation is at the time of the contribution.

   o  Added "older versions of " to the reference to IE uri length
      limitations.

   o  Stopped talking about signed or unsigned JWS etc.

   o  1.Introduction improved.

   -06

   o  Added explanation on the 512 chars URL restriction.

   o  Updated Acknowledgements.

   -05

   o  More alignment with OpenID Connect.

   -04

   o  Fixed typos in examples. (request_url -> request_uri, cliend_id ->
      client_id)

   o  Aligned the error messages with the OAuth IANA registry.

   o  Added another rationale for having request object.

   -03

   o  Fixed the non-normative description about the advantage of static
      signature.

   o  Changed the requirement for the parameter values in the request
      itself and the request object from 'MUST MATCH" to 'Req Obj takes
      precedence.

   -02

   o  Now that they are RFCs, replaced JWS, JWE, etc. with RFC numbers.

   -01

   o  Copy Edits.

11.  References

11.1.  Normative References

   [FIPS180-2]
              U.S. Department of Commerce and National Institute of
              Standards and Technology, "Secure Hash Signature
              Standard", FIPS 180-2, August 2002.

              Defines Secure Hash Algorithm 256 (SHA256)

   [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>.

   [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>.

   [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>.

   [RFC6819]  Lodderstedt, T., Ed., McGloin, M., and P. Hunt, "OAuth 2.0
              Threat Model and Security Considerations", RFC 6819,
              DOI 10.17487/RFC6819, January 2013,
              <http://www.rfc-editor.org/info/rfc6819>.

   [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>.

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

   [RFC7516]  Jones, M. and J. Hildebrand, "JSON Web Encryption (JWE)",
              RFC 7516, DOI 10.17487/RFC7516, May 2015,
              <http://www.rfc-editor.org/info/rfc7516>.

   [RFC7518]  Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
              DOI 10.17487/RFC7518, May 2015,
              <http://www.rfc-editor.org/info/rfc7518>.

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

11.2.  Informative References

   [OpenID.Core]
              Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and
              C. Mortimore, "OpenID Connect Core 1.0", February 2014.

Authors' Addresses

   Nat Sakimura (editor)
   Nomura Research Institute
   1-6-5 Marunouchi, Marunouchi Kitaguchi Bldg.
   Chiyoda-ku, Tokyo  100-0005
   Japan

   Phone: +81-3-5533-2111
   Email: n-sakimura@nri.co.jp
   URI:   http://nat.sakimura.org/

   John Bradley
   Ping Identity
   Casilla 177, Sucursal Talagante
   Talagante, RM
   Chile

   Phone: +44 20 8133 3718
   Email: ve7jtb@ve7jtb.com
   URI:   http://www.thread-safe.com/