OAuth Working Group                                          N. Sakimura, Ed. Sakimura
Internet-Draft                                 Nomura Research Institute
Intended status: Standards Track                              J. Bradley
Expires: July 22, 2016 February 3, 2017                                  Ping Identity
                                                        January 19,
                                                          August 2, 2016

               OAuth 2.0 JWT Authorization Request
                       draft-ietf-oauth-jwsreq-07 (JAR)
                       draft-ietf-oauth-jwsreq-08

Abstract

   The authorization request in OAuth 2.0 [RFC6749] utilizes query
   parameter serialization, which means that Authorization Request
   parameters are encoded in the URI of the request. request and sent through
   user agents such as web browsers.  While it is easy to implement, it
   means that (a) the communication through the user agents are not
   integrity protected and thus the parameters can be tainted, and (b)
   the source of the communication is not authentciated.  Because of
   these weaknesses, several attacks to the protocol have now been put
   forward.

   This document introduces the ability to send request parameters in form of a
   JSON Web Token (JWT) instead, which allows the request to be JWS
   signed and/or JWE encrypted so that the integrity, source
   authentication and encrypted.  using JWT
   serialization. confidentiallity property of the Authorization
   Request is attained.  The request is can be sent by value or by
   reference.

Status of This Memo

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   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on July 22, 2016. February 3, 2017.

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   4   5
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4   5
     2.1.  Request Object  . . . . . . . . . . . . . . . . . . . . .   4   6
     2.2.  Request Object URI  . . . . . . . . . . . . . . . . . . .   5   6
   3.  Symbols and abbreviated terms . . . . . . . . . . . . . . . .   6
   4.  Request Object  . . . . . . . . . . . . . . . . . . . . . . .   5
   4.   6
   5.  Authorization Request . . . . . . . . . . . . . . . . . . . .   7
     4.1.   8
     5.1.  Passing a Request Object by Value . . . . . . . . . . . .   8
     4.2.   9
     5.2.  Passing a Request Object by Reference . . . . . . . . . .   8
       4.2.1.  10
       5.2.1.  URL Referencing the Request Object  . . . . . . . . .  10
       4.2.2.  12
       5.2.2.  Request using the "request_uri" Request Parameter . .  10
       4.2.3.  12
       5.2.3.  Authorization Server Fetches Request Object . . . . .  11
   5.  12
   6.  Validating JWT-Based Requests . . . . . . . . . . . . . . . .  11
     5.1.  13
     6.1.  Encrypted Request Object  . . . . . . . . . . . . . . . .  11
     5.2.  13
     6.2.  JWS Signed Request Object . . . . . . . . . . . . . . . . . .  11
     5.3.  13
     6.3.  Request Parameter Assembly and Validation . . . . . . . .  12
   6.  13
   7.  Authorization Server Response . . . . . . . . . . . . . . . .  12
   7.  IANA  Considerations  13
   8.  TLS Requirements  . . . . . . . . . . . . . . . . . . . .  12
   8.  Security . .  14
   9.  IANA  Considerations  . . . . . . . . . . . . . . . . . . .  12
   9.  Acknowledgements .  14
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  14
     10.1.  Choice of Algorithms . . . .  13
   10. Revision History . . . . . . . . . . . . . .  14
     10.2.  Choice of Parameters to include in the Request Object  .  14
     10.3.  Request Source Authentication  . . . . . . .  13
   11. References . . . . . .  15
   11. Privacy Considerations  . . . . . . . . . . . . . . . . . . .  15
     11.1.  Normative References  Collection limitation  . . . . . . . . . . . . . . . . . .  15  16
     11.2.  Informative References  Disclosure Limitation  . . . . . . . . . . . . . . . . .  16
   Authors' Addresses
       11.2.1.  Request Disclosure . . . . . . . . . . . . . . . . .  16
       11.2.2.  Tracking using Request Object URI  . . . . . .  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 . . .  17
   12. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   13. Revision History  . . . . . . . . . . . . . . . . . . . . . .  17
   14. References  . . . . . . . . . . . . . . . . . . . . . . . . .  19
     14.1.  Normative References . . . . . . . . . . . . . . . . . .  19
     14.2.  Informative References . . . . . . . . . . . . . . . . .  20
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  21

1.  Introduction

   The Authorization Request in OAuth 2.0 [RFC6749] utilizes query
   parameter serialization and typically sent through user agents such
   as web browsers.

   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

   While it is easy to implement, 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 Client and the
   resource server, user-agent and the user-agent and
   the Authorization Server, TLS sessions are terminated in the user-
   agent.  In addition, TLS sessions are often terminated prematurely at some
   middlebox (such as a load balancer).  The use

   As the result, the Authorization Request of application
   layer security additionally allows requests to be prepared by [RFC6749] has a third
   party so property
   that a client

   (a)  the communication through the user agents are not integrity
        protected and thus the parameters can be tainted (integrity
        protection failure);

   (b)  the source of the communication is not authentciated (source
        authentication failure); and

   (c)  the communication through the user agents can be monitored
        (containment failure).

   Because of these weaknesses, several attacks to the protocol such as
   Redirection URI rewrite has been put forward by now.

   The use of application layer security mitigates these issues.

   In addition, it 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 reduction of over-the-
   wire overhead.

   There are other potential formats that could be used for this purpose
   instead of JWT. JWT [RFC7519].  The JWT was chosen because of

   1.

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

   2.

   (2)  its developer friendliness due to its textaual textual nature;

   3.

   (3)  its relative compactness compared to XML;

   4.

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

   (5)  relative ease of JWS and JWE compared to XML Signature and
        Encryption.

   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.  This JWT is integrity protected
   and source authenticated using JWS.

   The JWT [RFC7519] can be passed to
   the authorization endpoint by reference, 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:

   (a)  (integrity protection) The request can be signed so that the
        integrity of the request can be checked ;

   (b)  (source authentication) The request can be signed so that the
        signer can be authenticated ;

   (c)  (containment) The request can be encrypted so that end-to-end
        confidentiality can be provided even if the TLS connection is
        terminated at one point or another ; and

   (d)  (collection minimization) The request can 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
        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 desirable to reduce the size of transmitted request.
       The use of application layer security increases the size of the
       request, particularly when public key cryptography is used.

   2.  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 contents of the
       resources referenced by the Request Object URI.  With this, the
       server knows if the resource has changed without fetching it, so
       it does not have to re-fetch the same content, which is a win as
       well.  This is explained in Section 5.2.

   4.  When the client does not want to do the crypto: The Authorization
       Server may provide an endpoint to accept the Authorization
       Request through direct communication with the Client so that the
       Client is authentcicated and the channel is TLS protected.

   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 in addition to what is defined in OAuth 2.0 Framework
   [RFC6749], JSON Web Signature [RFC7515], and JSON Web Encryption
   [RFC7519] 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.  Symbols and abbreviated terms

   The following abbreviations are common to this specification.

   JSON  Javascript Object Notation

   JWT  JSON Web Token

   JWS  JSON Web Signature

   JWE  JSON Web Encryption

   URI  Uniform Resource Identifier

   URL  Uniform Resource Locator

   WAP  Wireless Application Protocol

4.  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.  The parameters are represented as
   the JWT claims.  Parameter names and string values MUST be included
   as JSON strings.  Since it is a JWT, JSON strings MUST be represented
   in UTF-8.  Numerical values MUST be included as JSON numbers.  It MAY
   include any extension parameters.  This JSON [RFC7159] constitutes
   the JWT Claims Set [RFC7519].  The JWS Claims Set is then signed,
   encrypted, or signed and encrypted.

   To sign, JSON Web Signature (JWS) [RFC7515] is used.  The result is a
   JWS 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.

   To encrypt, JWE [RFC7516] is used.  Unless the algorithm used in JWE
   allows for the source to be authenticated, JWS signature should also
   be applied.  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 be sent by value as described in
   Section 5.1 or by reference as described in Section 5.2.

   Required OAuth 2.0 Authorization Request parameters that are not
   included in the Request Object MUST be sent as query parameters.  If
   a required parameter is missing from both the query parameters and
   the Request Object, 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 take
   precedence.  This means that if it intends to use a cached request
   object, it cannot include parameters such as "state" that are
   expected to differ in every request.  It is fine to include them in which case
   the parameter
   "request_uri" request object if it is used instead going to be prepared afresh every time.

   The following is a non-normative example of the "request".

   Using JWT [RFC7519] Claims in a Request
   Object before base64url encoding and signing.  Note that it includes
   extension variables such as "nonce" and "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
     }

   Signing it with the request encoding instead of query
   parameters has several advantages:

   1. "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 request can be signed so that an integrity check following RSA public key, represented in JWK format, can be
       implemented.  If a suitable algorithm is 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"
     }

5.  Authorization Request

   The client constructs the signing,
       then it will provide verification authorization request URI by adding one of
   the client making following parameters but not both to the
       request.

   2.  The query component of the
   authorization endpoint URI using the "application/x-www-form-
   urlencoded" format:

   request may be encrypted so  The Request Object (Section 4) that end-to-end confidentiality
       may be obtained even if holds authorization
      request parameters stated 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 section 4 of OAuth 2.0 [RFC6749].

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

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

   For example, a request can be pre-examined by a third party that all the personal data requested is strictly necessary to perform client directs the
       process that end-user's user-agent to make the end-user asked for, and statically signed by
       that third party.
   following HTTPS request:

   GET /authz?request=eyJhbG..AlMGzw HTTP/1.1
   Host: server.example.com

   The client would then send value for the request along
       with dynamic parameters such as state. parameter is abbreviated for brevity.

   The authorization server
       then examines the signature request object MUST be either

   (a)  JWS signed; or

   (b)  JWE encrypted; or

   (c)  JWS signed and shows JWE encrypted.

   When the conformance status to Request Object is used, the end-user, who would have some assurance as to OAuth 2.0 request parameter
   values contained in the legitimacy
       of JWS Signed and/or JWE Encrypted JWT supersede
   those passed using the OAuth 2.0 request when authorizing it.  In some cases, it may even syntax.  However, parameters
   MAY also be desirable to skip passed using the authorization dialogue under such
       circumstances.

   There are a few cases that OAuth 2.0 request by reference are useful such as:

   1.  When it syntax even when a
   Request Object is desirable used; this would typically be done to reduced the size of transmitted request.
       Since we are using application layer security, it may
       substantially increase the size of enable a
   cached, pre-signed (and possibly pre-encrypted) Request Object value
   to be used containing the fixed request particulary in the
       case of using public key cryptography.

   2.  Static signature: The client parameters, while parameters
   that can make vary with each request, such as "state" and "nonce" of
   OpenID Connect, are passed as OAuth 2.0 parameters.

5.1.  Passing a signed Request Object and
       put it at a place that by Value

   The Client sends the Authorization Server can access.  This
       may just be done by Request as a client utility or other process, so that
       the private key does not have Request Object to reside on the client,
       simplifying programming.  Downside of it is that the signed
       portion just become a token.

   3.  When the server wants
   Authorization Endpoint as the requests to be cacheable: "request" parameter value.

   The
       request_uri may include following is a SHA-256 hash of the contents non-normative example of the
       resources referenced by the an Authorization Request URI.  With this, the server
       knows if the resource has changed without fetching it, so it does
       not have to re-fetch
   using the same content, which is "request" parameter (with line wraps within values for
   display purposes only):

     https://server.example.com/authorize?
       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

5.2.  Passing a win as well.
       This is explained in Section 4.2.

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

1.1.  Requirements Language Reference

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are "request_uri" Authorization Request parameter enables OAuth
   authorization requests to be interpreted as described in RFC 2119 [RFC2119].

2.  Terminology

   For passed by reference, rather than by
   value.  This parameter is used identically to the purposes of this specification, "request"
   parameter, other than that the following terms and
   definitions apply.

2.1. Request Object

   JWT [RFC7519] that holds an 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 as parameter values contained in the referenced JWT
   Claims Set

2.2.  Request Object URI

   Absolute URI from which supersede
   those passed using 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 request syntax.  However, parameters
   MAY also be passed using the OAuth 2.0 [RFC6749] authorization 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
   including extension parameters.  The parameters are represented
   that can vary with each request, such as
   the JWT claims.  Parameter names "state" and string values MUST be included
   as JSON strings.  Numerical values MUST be included "nonce", are
   passed as JSON numbers.
   It MAY include any extension OAuth 2.0 parameters.  This JSON [RFC7159]
   constitutes

   Servers MAY cache the JWT Claims Set [RFC7519].  The JWS Claims Set is then
   signed, encrypted, or signed and encrypted.

   To sign, JSON Web Signature (JWS) [RFC7515] is used.  The result is a
   JWS signed JWT [RFC7519].  If signed, contents of the Authorization resources referenced by Request
   Object SHOULD contain URIs.  If the Claims "iss" (issuer) and "aud" (audience)
   as members, with their semantics being contents of the referenced resource could ever
   change, the URI SHOULD include the same base64url encoded SHA-256 hash as
   defined in RFC6234 [RFC6234] of the JWT
   [RFC7519] specification.

   To encrypt, JWE [RFC7516] is used.  Note that JWE is always integrity
   protected, so if only integrity protection is desired, JWS signature
   is not needed.

   It can also be signed then encrypted.  This is sometimes desired to
   reduced the repudiation risk from referenced resource contents as
   the point of view fragment component of the receiver.
   In this case, it MUST be signed then encrypted, with URI.  If the result being fragment value used for a Nested JWT, as defined in JWT [RFC7519].

   The Authorization Request Object may be sent by
   URI changes, that signals the server that any cached value as described in
   Section 4.1 or by reference as described in Section 4.2.

   REQUIRED OAuth 2.0 Authorization Request parameters for that are not
   included in
   URI with the old fragment value is no longer valid.

   The entire Request Object URI MUST be sent 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 query parameters.  If 2G mobile connection, a required parameter large URL
       would cause the slow response and using such is missing not advisable
       from both the query parameters and user experience point of view.

   The contents of the Request Object, resource referenced by the request is malformed.

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

   If the parameter exists in both the query string and the
   Authorization a Request Object, the values
   Object.  The scheme used in the "request_uri" value MUST be "https",
   unless the target Request Object take
   precedence.  This means that if it intends to use is signed in a cached request
   object, it cannot include parameters such as "state" way that are
   expected to differ in every request.  It is fine to include them in
   verifiable by the request object if it is going to Authorization Server.  The "request_uri" value MUST
   be prepared afresh every time. reachable by the Authorization Server, and SHOULD be reachable by
   the Client.

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

   Signing it with the "RS256" algorithm results in this Request Object
   value 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

5.2.1.  URL Referencing the Request Object

   The following RSA public key, represented in JWK format, Client stores the Request Object resource either locally or
   remotely at a URL the Authorization Server can access.  The URL MUST
   be HTTPS URL.  This URL is the Request Object URI, "request_uri".

   It is possible for the Request Object to include values that is to be
   revealed only to 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.

   Unless the access to validate the "request_uri" over TLS provides adequate
   authentciation of the source of the Request Object signature in this and subsequent Object, the Request
   Object MUST be JWS Signed.

   The following is a non-normative example of a Request Object examples URI
   value (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

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

5.2.2.  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" format:

   request "request_uri" Request Parameter

   The Client sends the Authorization Request Object (Section 3) that holds authorization
      request parameters stated in to the section 4 of OAuth 2.0 [RFC6749].

   request_uri Authorization
   Endpoint.

   The absolute URL that points to 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

5.2.3.  Authorization Server Fetches Request Object
      (Section 3) that holds authorization request parameters stated in
      the section 4

   Upon receipt of OAuth 2.0 [RFC6749].

   The client directs the resource owner to Request, the constructed URI using Authorization Server MUST send an
   HTTP redirection response, or by other means available "GET" request to the "request_uri" to retrieve the referenced
   Request Object, unless it via is already cached, and parse it to recreate
   the
   user-agent.

   For example, Authorization Request parameters.

   Note that the client directs SHOULD use a unique URI for each request
   containing distinct parameters values, or otherwise prevent the end-user's user-agent to make
   Authorization Server from caching the "request_uri".

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

     GET /authz?request=eyJhbG..AlMGzw /request.jwt 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 client.example.org

6.  Validating JWT-Based Requests

6.1.  Encrypted Request Object is used,

   The Authorization Server MUST decrypt the OAuth 2.0 request parameter
   values contained JWT in accordance with the JWT supersede those passed using
   JSON Web Encryption [RFC7516] specification.  If the OAuth
   2.0 result is a
   signed request syntax.  However, parameters MAY also object, signature validation MUST be passed using performed as
   defined in Section 6.2 as well.

   If decryption fails, 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) Authorization Server MUST return
   "invalid_request_object" error.

6.2.  JWS Signed Request Object

   To perform JWS Signature Validation, the "alg" Header Parameter in
   the JOSE Header MUST match the value to of the pre-registered algorithm.
   The signature MUST be used containing validated against the fixed
   request parameters, while parameters appropriate key for that can vary with each request,
   such as state
   "client_id" and nonce, are passed as OAuth 2.0 parameters.

4.1.  Passing a algorithm.

   If signature validation fails, the Authorization Server MUST return
   "invalid_request_object" error.

6.3.  Request Object by Value Parameter Assembly and Validation

   The Client sends Authorization Server MUST assemble the set of Authorization
   Request as a Request Object parameters to be used from the
   Authorization Endpoint as Request Object value and the "request" parameter value.

   The following is a non-normative example of an
   OAuth 2.0 Authorization Request
   using parameters (minus the "request" or
   "request_uri" parameters).  If the same 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 exists both in the
   Request Object by Reference

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

   When Authorization Server then
   validates the "request_uri" parameter request as specified in OAuth 2.0 [RFC6749].

7.  Authorization Server Response

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

   In addition, this document uses these additional error values:

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

   invalid_request_object  The request parameter values contained in contains an invalid
      Request Object.

   request_not_supported  The Authorization Server does not support the referenced JWT supersede
   those passed using
      use of the OAuth 2.0 request syntax.  However, parameters
   MAY also be passed using "request" parameter.

   request_uri_not_supported  The Authorization Server does not support
      use of 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) parameter.

8.  TLS Requirements

   Client implementations supporting the Request Object value
   to URI method MUST
   support TLS as recommended in Recommendations for Secure Use of
   Transport Layer Security (TLS) and Datagram Transport Layer Security
   (DTLS) [RFC7525].

   To protect against information disclosure and tampering,
   confidentiality protection MUST be used containing the fixed request parameters, while parameters
   that can vary applied using TLS with each request, such as "state" a
   ciphersuite that provides confidentiality and "nonce", are
   passed as integrity protection.

   Whenever TLS is used, the identity of the service provider encoded in
   the TLS server certificate MUST be verified using the procedures
   described in Section 6 of [RFC6125].

9.  IANA Considerations

   This specification requests no actions by IANA.

10.  Security Considerations

   In addition to the all the security considerations discussed in OAuth
   2.0 parameters.

   Servers MAY cache [RFC6819], the contents following security considerations should be taken
   into account.

10.1.  Choice of Algorithms

   When sending the resources referenced by Request
   URIs.  If the contents authorization request object through "request"
   parameter, it MUST either be JWS signed with then considered
   appropriate algorithm or encrypted using [RFC7516].

10.2.  Choice of the referenced resource could ever change,
   the URI SHOULD Parameters to 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 Request Object

   Unless there is a URI
   changes, compelling reasons to do otherwise, it is strongly
   recommended to create a request object that signals covers all the server that any cached value for parameters
   so 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 request is 2083 ASCII characters.

   3.  On a slow connection such as 2G mobile connection, a large URL
       would cause integrity protected.

   This means that the slow response request object is going to be prepared fresh each
   time an authorization request is made and using cacheing cannot be used.
   It has a performance disadvantage, but where such disadvantage is not advisable
       from the user experience point of view.

   The contents of
   permissible, it should be considered.

   Unless the resource referenced by server and the URL MUST be a Request
   Object.  The scheme used in client have agreed prior to the "request_uri" value MUST be "https",
   unless
   authorization request to use the target Request Object is signed in non-protected parameters, the
   authorization server SHOULD reject a way request that is
   verifiable by the Authorization Server. not fully
   integrity protected and source authenticated.

10.3.  Request Source Authentication

   The "request_uri" value MUST
   be reachable by source of the Authorization Server, and SHOULD Request MUST always be reachable by verified.
   There are several ways to do it in this sepcification.

   (a)  Verifying the Client.

   The following is a non-normative example JWS Signature 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 Object.

   (b)  Verifying the Request Object

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

   It is possible for MUST know out of band that
        the Client uses Request Object to include values that is to be
   revealed URI and only to the Authorization Server.  As such, the
   "request_uri" MUST have appropriate entropy for its lifetime.  It Client is
   RECOMMENDED that it be removed if
        covered by the TLS certificate.  In general, 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
        reliable method.

   (c)  Authorization
   Endpoint.

   The following Server is a non-normative example of providing an Authorization endpoint that provides a
        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 Object URI in exchange for a Request Object

   Upon receipt of the Request, Object.  In this
        case, the Authorization Server MUST send an
   HTTP "GET" request peform Client Authentication
        to accept the "request_uri" Request Object and bind the Client Identifier to retrieve
        the referenced Request Object, unless Object URI it is already cached, providing.  Since Request Object
        URI can be replayed, the lifetime of the Request Object URI MUST
        be short and parse it to recreate preferably one-time use.  The entropy of the Authorization
        Request parameters.

   Note Object URI MUST be sufficiently large.

   (d)  A third party, such as a Trust Framework Provider, provides an
        endpoint that the client SHOULD use provides a unique Request Object URI in exchange 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 Object.  The same requirements as (b) above applies.  In
        addition, the Authorization Server MUST decrypt know out-of-band that
        the JWT in accordance with Client utilizes the
   JSON Web Encryption [RFC7516] specification.  If Trust Framework Operator.

11.  Privacy Considerations

   When the result Client is being granted access to a
   signed request object, signature validation MUST be performed as
   defined in Section 5.2 as well.

   The protected resource
   containing personal data, both the Client and the Authorization
   Server MUST return an error if decryption fails.

5.2.  Signed Request Object

   To perform Signature Validation, need to adhere to Privacy Principles.  ISO/IEC 29100
   [ISO29100] is a freely accessible International Standard and its
   Privacy Principles are good to follow.

   Most of the provision would apply to The OAuth 2.0 Authorization
   Framework [RFC6749] and The OAuth 2.0 Authorization Framework: Bearer
   Token Usage [RFC6750] and not specific to this specification.  In
   what follows, only the specific provisions to this specification are
   noted.

11.1.  Collection limitation

   When the Client is being granted access to a protected resource
   containing personal data, the Client SHOULD limit the collection of
   personal data to that which is within the bounds of applicable law
   and strictly necessary for the specified purpose(s).

   It is often hard for the user to find out if the "alg" Header Parameter in personal data asked
   for is strictly necessary.  A Trust Framework Provider can help the
   JOSE Header MUST match
   user by examining the value of Client request and comparing to the pre-registered algorithm.
   The signature MUST be validated against proposed
   processing by the appropriate key for that
   "client_id" Client and algorithm.

   The Authorization Server MUST return certifying the request.  After the
   certification, the Client, when making an error if signature validation
   fails.

5.3.  Request Parameter Assembly and Validation

   The Authorization Server MUST assemble the set of Request, can
   submit Authorization Request parameters to be used from the Trust Framework Provider to
   obtain the Request Object value and the
   OAuth 2.0 Authorization URI.

   Upon receiving such Request parameters (minus the "request" or
   "request_uri" parameters).  If the same parameter exists both Object URI in the
   Request Object and Authorization Request,
   the OAuth Authorization Request parameters, Server first verifies that the
   parameter in authority portion of
   the Request Object URI is used.  Using a legitimate one for the assembled set of
   Authorization Request parameters, Trust Framework
   Provider.  Then, the Authorization Auhtorization Server then
   validates the issues HTTP GET request as specified in OAuth 2.0 [RFC6749].

6.  Authorization Server Response to
   the Request Object URI.  Uppon connecting, the Authorization Server Response is created and sent to
   MUST verify the client as in
   Section 4 of OAuth 2.0 [RFC6749] .

   In addition, this document uses these additional error values:

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

   invalid_request_object  The request parameter contains an invalid TLS certificate is
   legitimate for the Request Object.

   request_not_supported  The Object URI.  Then, the Authorization
   Server does not support can obtain the
      use of Request Object, which includes the "request" parameter.

   request_uri_not_supported "client_id"
   representing the Client.

   The Authorization Server does not support
      use of Consent screen MUST indicate the "request_uri" parameter.

7.  IANA Considerations

   This specification requests no actions by IANA.

8.  Security Considerations

   In addition to Client and SHOULD indicate that
   the request has been vetted by the all Trust Framework Operator for the security considerations discussed in OAuth
   2.0 [RFC6819],
   adherance to the following security considerations SHOULD be taken
   into account.

   When sending Collection Limitation principle.

11.2.  Disclosure Limitation

11.2.1.  Request Disclosure

   This specification allows extension parameters.  These may include
   potentially sensitive information.  Since URI query parameter may
   leak through various means but most notably through referrer and
   browser history, if the authorization request object through "request" contains poteintially
   sensitive parameter, it SHOULD be signed with then considered appropriate
   algorithm using [RFC7515].  The "alg=none" the Client SHOULD NOT be used in such
   a case.

   If JWE [RFC7516] encrypt the
   request object.

   Where Request Object URI method is being used, if the request object
   contains personally identifiable or sensitive information, the
   "request_uri" MUST SHOULD be of one-time use and MUST have large enough
   entropy deemed necessary with applicable security
   policy.  For higher security requirement, using policy unless the
   Request Object itself is JWE [RFC7516] Encrypted.

11.2.2.  Tracking using Request Object URI

   Even if the protected resource does not include a personally
   identifiable information, it is strongly
   recommended.

9. sometimes possible to identify the
   user through the Request Object URI if persistent per-user Request
   Object URI is used.  A third party may observe it through borwser
   history etc. and start corrilating the user's activity using it.  It
   is in a way a data disclosure as well and should be avoided.

   Therefore, per-user Request Object URI should be avoided.

12.  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), Vladimir Dzhuvinov
   (Connect2id), Michael B.  Jones (Microsoft), Torsten Lodderstedt
   (Deutche Telecom) Jim Manico, Axel Nenker(DT), Nenker(Deutche Telecom), Hannes
   Tschofenig (ARM), (add yourself).

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

   Brian Campbell (Ping Identity), George Fletcher (AOL), Ryo Itou
   (Yahoo!  Japan),
   (Mixi), 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.

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

10. (Facebook).

13.  Revision History

   -08

   o  Applied changes proposed by Hannes on 2016-06-29 on IETF OAUth
      list recorded as https://bitbucket.org/Nat/oauth-jwsreq/
      issues/12/.

   o  TLS requirements added.

   o  Security Consideration reinforced.

   o  Privacy Consideration added.

   o  Introduction improved.

   -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.

14.  References

11.1.

14.1.  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.

   [RFC6125]  Saint-Andre, P. and E. Rescorla, "The 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) Protocol Version 1.2", (TLS)", RFC 5246, 6125, DOI 10.17487/RFC5246, August 2008,
              <http://www.rfc-editor.org/info/rfc5246>. 10.17487/RFC6125, March
              2011, <http://www.rfc-editor.org/info/rfc6125>.

   [RFC6234]  Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
              (SHA and SHA-based HMAC and HKDF)", RFC 6234,
              DOI 10.17487/RFC6234, May 2011,
              <http://www.rfc-editor.org/info/rfc6234>.

   [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>.

   [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.

   [RFC7525]  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/rfc7525>.

14.2.  Informative References

   [ISO29100]
              "ISO/IEC 29100 Information technology - Security
              techniques - Privacy framework", December 2011,
              <http://standards.iso.org/ittf/PubliclyAvailableStandards/
              c045123_ISO_IEC_29100_2011.zip>.

   [OpenID.Core]
              Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and
              C. Mortimore, "OpenID Connect Core 1.0", February 2014. 2014,
              <http://openid.net/specs/openid-connect-core-1_0.html>.

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/