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Versions: (draft-jones-json-web-token) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22

OAuth Working Group                                             M. Jones
Internet-Draft                                                 Microsoft
Intended status: Standards Track                              J. Bradley
Expires: November 23, 2012                                 Ping Identity
                                                             N. Sakimura
                                                                     NRI
                                                            May 22, 2012


                          JSON Web Token (JWT)
                   draft-ietf-oauth-json-web-token-00

Abstract

   JSON Web Token (JWT) is a means of representing claims to be
   transferred between two parties.  The claims in a JWT are encoded as
   a JSON object that is digitally signed or MACed using JSON Web
   Signature (JWS) and/or encrypted using JSON Web Encryption (JWE).

   The suggested pronunciation of JWT is the same as the English word
   "jot".

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].

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 23, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the



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   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.








































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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  JSON Web Token (JWT) Overview  . . . . . . . . . . . . . . . .  5
     3.1.  Example JWT  . . . . . . . . . . . . . . . . . . . . . . .  6
   4.  JWT Claims . . . . . . . . . . . . . . . . . . . . . . . . . .  6
     4.1.  Reserved Claim Names . . . . . . . . . . . . . . . . . . .  7
       4.1.1.  "exp" (Expiration Time) Claim  . . . . . . . . . . . .  7
       4.1.2.  "nbf" (Not Before) Claim . . . . . . . . . . . . . . .  7
       4.1.3.  "iat" (Issued At) Claim  . . . . . . . . . . . . . . .  7
       4.1.4.  "iss" (Issuer) Claim . . . . . . . . . . . . . . . . .  8
       4.1.5.  "aud" (Audience) Claim . . . . . . . . . . . . . . . .  8
       4.1.6.  "prn" (Principal) Claim  . . . . . . . . . . . . . . .  8
       4.1.7.  "jti" (JWT ID) Claim . . . . . . . . . . . . . . . . .  8
       4.1.8.  "typ" (Type) Claim . . . . . . . . . . . . . . . . . .  8
     4.2.  Public Claim Names . . . . . . . . . . . . . . . . . . . .  8
     4.3.  Private Claim Names  . . . . . . . . . . . . . . . . . . .  9
   5.  JWT Header . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     5.1.  "typ" (Type) Header Parameter  . . . . . . . . . . . . . . 10
   6.  Plaintext JWTs . . . . . . . . . . . . . . . . . . . . . . . . 10
     6.1.  Example Plaintext JWT  . . . . . . . . . . . . . . . . . . 10
   7.  Rules for Creating and Validating a JWT  . . . . . . . . . . . 11
   8.  Cryptographic Algorithms . . . . . . . . . . . . . . . . . . . 13
   9.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 13
     9.1.  JSON Web Token Claims Registry . . . . . . . . . . . . . . 14
     9.2.  Sub-Namespace Registration of
           urn:ietf:params:oauth:token-type:jwt . . . . . . . . . . . 14
     9.3.  Registration of application/jwt MIME Media Type  . . . . . 14
     9.4.  Registration of "JWT" Type Value . . . . . . . . . . . . . 15
   10. Security Considerations  . . . . . . . . . . . . . . . . . . . 16
   11. Open Issues and Things To Be Done (TBD)  . . . . . . . . . . . 16
   12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     12.1. Normative References . . . . . . . . . . . . . . . . . . . 16
     12.2. Informative References . . . . . . . . . . . . . . . . . . 17
   Appendix A.  Relationship of JWTs to SAML Tokens . . . . . . . . . 18
   Appendix B.  Relationship of JWTs to Simple Web Tokens (SWTs)  . . 18
   Appendix C.  Acknowledgements  . . . . . . . . . . . . . . . . . . 18
   Appendix D.  Document History  . . . . . . . . . . . . . . . . . . 19
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19











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1.  Introduction

   JSON Web Token (JWT) is a compact token format intended for space
   constrained environments such as HTTP Authorization headers and URI
   query parameters.  JWTs encode claims to be transmitted as a JSON
   object (as defined in RFC 4627 [RFC4627]) that is base64url encoded
   and digitally signed or MACed and/or encrypted.  Signing and MACing
   is performed using JSON Web Signature (JWS) [JWS].  Encryption is
   performed using JSON Web Encryption (JWE) [JWE].

   The suggested pronunciation of JWT is the same as the English word
   "jot".


2.  Terminology

   JSON Web Token (JWT)  A string consisting of multiple parts, the
      first being the Encoded JWT Header, plus additional parts
      depending upon the contents of the header, with the parts being
      separated by period ('.') characters, and each part containing
      base64url encoded content.

   JWT Header  A string representing a JSON object that describes the
      cryptographic operations applied to the JWT.  When the JWT is
      digitally signed or MACed, the JWT Header is a JWS Header.  When
      the JWT is encrypted, the JWT Header is a JWE Header.

   Header Parameter Names  The names of the members within the JWT
      Header.

   Header Parameter Values  The values of the members within the JWT
      Header.

   JWT Claims Set  A string representing a JSON object that contains the
      claims conveyed by the JWT.  When the JWT is digitally signed or
      MACed, the bytes of the UTF-8 representation of the JWT Claims Set
      are base64url encoded to create the Encoded JWS Payload.  When the
      JWT is encrypted, the bytes of the UTF-8 representation of the JWT
      Claims Set are used as the JWE Plaintext.

   Claim Names  The names of the members of the JSON object represented
      by the JWT Claims Set.

   Claim Values  The values of the members of the JSON object
      represented by the JWT Claims Set.






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   Encoded JWT Header  Base64url encoding of the bytes of the UTF-8 RFC
      3629 [RFC3629] representation of the JWT Header.

   Base64url Encoding  For the purposes of this specification, this term
      always refers to the URL- and filename-safe Base64 encoding
      described in RFC 4648 [RFC4648], Section 5, with the (non URL-
      safe) '=' padding characters omitted, as permitted by Section 3.2.
      (See Appendix C of [JWS] for notes on implementing base64url
      encoding without padding.)

   StringOrURI  A JSON string value, with the additional requirement
      that while arbitrary string values MAY be used, any value
      containing a ":" character MUST be a URI as defined in RFC 3986
      [RFC3986].

   IntDate  A JSON numeric value representing the number of seconds from
      1970-01-01T0:0:0Z UTC until the specified UTC date/time.  See RFC
      3339 [RFC3339] for details regarding date/times in general and UTC
      in particular.


3.  JSON Web Token (JWT) Overview

   JWTs represent a set of claims as a JSON object that is base64url
   encoded and digitally signed or MACed and/or encrypted.  The JWT
   Claims Set represents this JSON object.  As per RFC 4627 [RFC4627]
   Section 2.2, the JSON object consists of zero or more name/value
   pairs (or members), where the names are strings and the values are
   arbitrary JSON values.  These members are the claims represented by
   the JWT.

   The member names within the JWT Claims Set are referred to as Claim
   Names.  The corresponding values are referred to as Claim Values.

   The bytes of the UTF-8 representation of the JWT Claims Set are
   digitally signed or MACed in the manner described in JSON Web
   Signature (JWS) [JWS] and/or encrypted in the manner described in
   JSON Web Encryption (JWE) [JWE].

   The contents of the JWT Header describe the cryptographic operations
   applied to the JWT Claims Set. If the JWT Header is a JWS Header, the
   claims are digitally signed or MACed.  If the JWT Header is a JWE
   Header, the claims are encrypted.

   A JWT is represented as a JWS or JWE.  The number of parts is
   dependent upon the representation of the resulting JWS or JWE.





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3.1.  Example JWT

   The following example JWT Header declares that the encoded object is
   a JSON Web Token (JWT) and the JWT is MACed using the HMAC SHA-256
   algorithm:
   {"typ":"JWT",
    "alg":"HS256"}

   Base64url encoding the bytes of the UTF-8 representation of the JWT
   Header yields this Encoded JWS Header value, which is used as the
   Encoded JWT Header:
   eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9

   The following is an example of a JWT Claims Set:
   {"iss":"joe",
    "exp":1300819380,
    "http://example.com/is_root":true}

   Base64url encoding the bytes of the UTF-8 representation of the JSON
   Claims Set yields this Encoded JWS Payload (with line breaks for
   display purposes only):
   eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly
   9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ

   Signing the Encoded JWS Header and Encoded JWS Payload with the HMAC
   SHA-256 algorithm and base64url encoding the signature in the manner
   specified in [JWS], yields this Encoded JWS Signature:
   dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

   Concatenating these parts in this order with period characters
   between the parts yields this complete JWT (with line breaks for
   display purposes only):
   eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
   .
   eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
   cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
   .
   dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

   This computation is illustrated in more detail in [JWS], Appendix
   A.1.


4.  JWT Claims

   The JWT Claims Set represents a JSON object whose members are the
   claims conveyed by the JWT.  The Claim Names within this object MUST
   be unique; JWTs with duplicate Claim Names MUST be rejected.  Note



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   however, that the set of claims that a JWT must contain to be
   considered valid is context-dependent and is outside the scope of
   this specification.  When used in a security-related context,
   implementations MUST understand and support all of the claims
   present; otherwise, the JWT MUST be rejected for processing.

   There are three classes of JWT Claim Names: Reserved Claim Names,
   Public Claim Names, and Private Claim Names.

4.1.  Reserved Claim Names

   The following claim names are reserved.  None of the claims defined
   below are intended to be mandatory, but rather, provide a starting
   point for a set of useful, interoperable claims.  All the names are
   short because a core goal of JWTs is for the tokens to be compact.
   Additional reserved claim names MAY be defined via the IANA JSON Web
   Token Claims registry Section 9.1.

4.1.1.  "exp" (Expiration Time) Claim

   The "exp" (expiration time) claim identifies the expiration time on
   or after which the token MUST NOT be accepted for processing.  The
   processing of the "exp" claim requires that the current date/time
   MUST be before the expiration date/time listed in the "exp" claim.
   Implementers MAY provide for some small leeway, usually no more than
   a few minutes, to account for clock skew.  Its value MUST be a number
   containing an IntDate value.  This claim is OPTIONAL.

4.1.2.  "nbf" (Not Before) Claim

   The "nbf" (not before) claim identifies the time before which the
   token MUST NOT be accepted for processing.  The processing of the
   "nbf" claim requires that the current date/time MUST be after or
   equal to the not-before date/time listed in the "nbf" claim.
   Implementers MAY provide for some small leeway, usually no more than
   a few minutes, to account for clock skew.  Its value MUST be a number
   containing an IntDate value.  This claim is OPTIONAL.

4.1.3.  "iat" (Issued At) Claim

   The "iat" (issued at) claim identifies the time at which the JWT was
   issued.  This claim can be used to determine the age of the token.
   Its value MUST be a number containing an IntDate value.  This claim
   is OPTIONAL.







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4.1.4.  "iss" (Issuer) Claim

   The "iss" (issuer) claim identifies the principal that issued the
   JWT.  The processing of this claim is generally application specific.
   The "iss" value is case sensitive.  Its value MUST be a string
   containing a StringOrURI value.  This claim is OPTIONAL.

4.1.5.  "aud" (Audience) Claim

   The "aud" (audience) claim identifies the audience that the JWT is
   intended for.  The principal intended to process the JWT MUST be
   identified with the value of the audience claim.  If the principal
   processing the claim does not identify itself with the identifier in
   the "aud" claim value then the JWT MUST be rejected.  The
   interpretation of the audience value is generally application
   specific.  The "aud" value is case sensitive.  Its value MUST be a
   string containing a StringOrURI value.  This claim is OPTIONAL.

4.1.6.  "prn" (Principal) Claim

   The "prn" (principal) claim identifies the subject of the JWT.  The
   processing of this claim is generally application specific.  The
   "prn" value is case sensitive.  Its value MUST be a string containing
   a StringOrURI value.  This claim is OPTIONAL.

4.1.7.  "jti" (JWT ID) Claim

   The "jti" (JWT ID) claim provides a unique identifier for the JWT.
   The identifier value MUST be assigned in a manner that ensures that
   there is a negligible probability that the same value will be
   accidentally assigned to a different data object.  The "jti" claim
   can be used to prevent the JWT from being replayed.  The "jti" value
   is case sensitive.  Its value MUST be a string.  This claim is
   OPTIONAL.

4.1.8.  "typ" (Type) Claim

   The "typ" (type) claim is used to declare a type for the contents of
   this JWT Claims Set. The "typ" value is case sensitive.  Its value
   MUST be a string.  This claim is OPTIONAL.

   The values used for the "typ" claim SHOULD come from the same value
   space as the "typ" header parameter, with the same rules applying.

4.2.  Public Claim Names

   Claim names can be defined at will by those using JWTs.  However, in
   order to prevent collisions, any new claim name SHOULD either be



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   defined in the IANA JSON Web Token Claims registry Section 9.1 or be
   a URI that contains a collision resistant namespace.  Examples of
   collision resistant namespaces include:

   o  Domain Names,

   o  Object Identifiers (OIDs) as defined in the ITU-T X.660 and X.670
      Recommendation series, or

   o  Universally Unique IDentifier (UUID) as defined in RFC 4122
      [RFC4122].

   In each case, the definer of the name or value needs to take
   reasonable precautions to make sure they are in control of the part
   of the namespace they use to define the claim name.

4.3.  Private Claim Names

   A producer and consumer of a JWT may agree to any claim name that is
   not a Reserved Name Section 4.1 or a Public Name Section 4.2.  Unlike
   Public Names, these private names are subject to collision and should
   be used with caution.


5.  JWT Header

   The members of the JSON object represented by the JWT Header describe
   the cryptographic operations applied to the JWT and optionally,
   additional properties of the JWT.  The member names within the JWT
   Header are referred to as Header Parameter Names.  These names MUST
   be unique; JWTs with duplicate Header Parameter Names MUST be
   rejected.  The corresponding values are referred to as Header
   Parameter Values.

   Implementations MUST understand the entire contents of the header;
   otherwise, the JWT MUST be rejected for processing.

   There are two ways of distinguishing whether the JWT is a JWS or JWE.
   The first is by examining the "alg" (algorithm) header value.  If the
   value represents a signature algorithm, the JWT is a JWS; if it
   represents an encryption algorithm, the JWT is a JWE.  A second
   method is determining whether an "enc" (encryption method) member
   exists.  If the "enc" member exists, the JWT is a JWE; otherwise, the
   JWT is a JWS.  Both methods will yield the same result.

   JWS Header Parameters are defined by [JWS].  JWE Header Parameters
   are defined by [JWE].  This specification further specifies the use
   of the following header parameters in both the cases where the JWT is



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   a JWS and where it is a JWE.

5.1.  "typ" (Type) Header Parameter

   The "typ" (type) header parameter is used to declare structural
   information about the JWT.  In the normal case where nested signing
   or encryption operations are not employed, the use of this header
   parameter is OPTIONAL, and if present, it is RECOMMENDED that its
   value be either "JWT" or "urn:ietf:params:oauth:token-type:jwt".  In
   the case that nested signing or encryption steps are employed, the
   use of this header parameter is REQUIRED; in this case, the value
   MUST either be "JWS", to indicate that a nested digitally signed or
   MACed JWT is carried in this JWT or "JWE", to indicate that a nested
   encrypted JWT is carried in this JWT.


6.  Plaintext JWTs

   To support use cases where the JWT content is secured by a means
   other than a signature and/or encryption contained within the token
   (such as a signature on a data structure containing the token), JWTs
   MAY also be created without a signature or encryption.  A plaintext
   JWT is a JWS using the "none" JWS "alg" header parameter value
   defined in JSON Web Algorithms (JWA) [JWA]; it is a JWS with an empty
   JWS Signature value.

6.1.  Example Plaintext JWT

   The following example JWT Header declares that the encoded object is
   a Plaintext JWT:
   {"alg":"none"}

   Base64url encoding the bytes of the UTF-8 representation of the JWT
   Header yields this Encoded JWT Header:
   eyJhbGciOiJub25lIn0

   The following is an example of a JWT Claims Set:
   {"iss":"joe",
    "exp":1300819380,
    "http://example.com/is_root":true}

   Base64url encoding the bytes of the UTF-8 representation of the JSON
   Claims Set yields this Encoded JWS Payload (with line breaks for
   display purposes only):
   eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
   cGxlLmNvbS9pc19yb290Ijp0cnVlfQ

   The Encoded JWS Signature is the empty string.



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   Concatenating these parts in this order with period characters
   between the parts yields this complete JWT (with line breaks for
   display purposes only):
   eyJhbGciOiJub25lIn0
   .
   eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
   cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
   .


7.  Rules for Creating and Validating a JWT

   To create a JWT, one MUST perform these steps.  The order of the
   steps is not significant in cases where there are no dependencies
   between the inputs and outputs of the steps.

   1.  Create a JWT Claims Set containing the desired claims.  Note that
       white space is explicitly allowed in the representation and no
       canonicalization is performed before encoding.

   2.  Let the Message be the bytes of the UTF-8 representation of the
       JWT Claims Set.

   3.  Create a JWT Header containing the desired set of header
       parameters.  The JWT MUST conform to either the [JWS] or [JWE]
       specifications.  Note that white space is explicitly allowed in
       the representation and no canonicalization is performed before
       encoding.

   4.  Base64url encode the bytes of the UTF-8 representation of the JWT
       Header.  Let this be the Encoded JWT Header.

   5.  Depending upon whether the JWT is a JWS or JWE, there are two
       cases:

       *  If the JWT is a JWS, create a JWS using the JWT Header as the
          JWS Header and the Message as the JWS Payload; all steps
          specified in [JWS] for creating a JWS MUST be followed.

       *  Else, if the JWT is a JWE, create a JWE using the JWT Header
          as the JWE Header and the Message as the JWE Plaintext; all
          steps specified in [JWE] for creating a JWE MUST be followed.

   6.  If a nested signing or encryption operation will be performed,
       let the Message be the JWS or JWE, and return to Step 3, using a
       "typ" value of either "JWS" or "JWE" respectively in the new JWT
       Header created in that step.




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   7.  Otherwise, let the resulting JWT be the JWS or JWE.

   When validating a JWT the following steps MUST be taken.  The order
   of the steps is not significant in cases where there are no
   dependencies between the inputs and outputs of the steps.  If any of
   the listed steps fails then the token MUST be rejected for
   processing.

   1.   The JWT MUST contain at least one period character.

   2.   Let the Encoded JWT Header be the portion of the JWT before the
        first period character.

   3.   The Encoded JWT Header MUST be successfully base64url decoded
        following the restriction given in this specification that no
        padding characters have been used.

   4.   The resulting JWT Header MUST be completely valid JSON syntax
        conforming to RFC 4627 [RFC4627].

   5.   The resulting JWT Header MUST be validated to only include
        parameters and values whose syntax and semantics are both
        understood and supported.

   6.   Determine whether the JWT is a JWS or a JWE by examining the
        "alg" (algorithm) header value and optionally, the "enc"
        (encryption method) header value, if present.

   7.   Depending upon whether the JWT is a JWS or JWE, there are two
        cases:

        *  If the JWT is a JWS, all steps specified in [JWS] for
           validating a JWS MUST be followed.  Let the Message be the
           result of base64url decoding the JWS Payload.

        *  Else, if the JWT is a JWE, all steps specified in [JWE] for
           validating a JWE MUST be followed.  Let the Message be the
           JWE Plaintext.

   8.   If the JWT Header contains a "typ" value of either "JWS" or
        "JWE", then the Message contains a JWT that was the subject of
        nested signing or encryption operations, respectively.  In this
        case, return to Step 1, using the Message as the JWT.

   9.   Otherwise, let the JWT Claims Set be the Message.

   10.  The JWT Claims Set MUST be completely valid JSON syntax
        conforming to RFC 4627 [RFC4627].



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   11.  When used in a security-related context, the JWT Claims Set MUST
        be validated to only include claims whose syntax and semantics
        are both understood and supported.

   Processing a JWT inevitably requires comparing known strings to
   values in the token.  For example, in checking what the algorithm is,
   the Unicode string encoding "alg" will be checked against the member
   names in the JWT Header to see if there is a matching header
   parameter name.  A similar process occurs when determining if the
   value of the "alg" header parameter represents a supported algorithm.

   Comparisons between JSON strings and other Unicode strings MUST be
   performed as specified below:

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

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

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


8.  Cryptographic Algorithms

   JWTs use JSON Web Signature (JWS) [JWS] and JSON Web Encryption (JWE)
   [JWE] to sign and/or encrypt the contents of the JWT.

   Of the JWS signing algorithms, only HMAC SHA-256 and "none" MUST be
   implemented by conforming JWT implementations.  It is RECOMMENDED
   that implementations also support the RSA SHA-256 and ECDSA P-256
   SHA-256 algorithms.  Support for other algorithms and key sizes is
   OPTIONAL.

   If an implementation provides encryption capabilities, of the JWE
   encryption algorithms, only RSA-PKCS1-1.5 with 2048 bit keys, AES-
   128-KW, AES-256-KW, AES-128-CBC, and AES-256-CBC MUST be implemented
   by conforming implementations.  It is RECOMMENDED that
   implementations also support ECDH-ES with 256 bit keys, AES-128-GCM,
   and AES-256-GCM.  Support for other algorithms and key sizes is
   OPTIONAL.


9.  IANA Considerations





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9.1.  JSON Web Token Claims Registry

   This specification establishes the IANA JSON Web Token Claims
   registry for reserved JWT claim names.  Inclusion in the registry is
   RFC Required in the RFC 5226 [RFC5226] sense.  The registry records
   the reserved claim name and a reference to the RFC that defines it.
   This specification registers the claim names defined in Section 4.1.

9.2.  Sub-Namespace Registration of urn:ietf:params:oauth:token-type:jwt

   This specification registers the value "token-type:jwt" in the
   registry urn:ietf:params:oauth established in An IETF URN Sub-
   Namespace for OAuth [I-D.ietf-oauth-urn-sub-ns].

   o  URN: urn:ietf:params:oauth:token-type:jwt

   o  Common Name: JSON Web Token (JWT) Token Type

   o  Change controller: IETF

   o  Description: [[this document]]

9.3.  Registration of application/jwt MIME Media Type

   This specification registers the "application/jwt" MIME Media Type
   RFC 2045 [RFC2045].

   Type name:
      application

   Subtype name:
      jwt

   Required parameters:
      n/a

   Optional parameters:
      n/a

   Encoding considerations:
      n/a

   Security considerations:
      See the Security Considerations section of this document







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   Interoperability considerations:
      n/a

   Published specification:
      [[ this document ]]

   Applications that use this media type:
      OpenID Connect, Mozilla Browser ID, Salesforce, Google, numerous
      others

   Additional information:
      Magic number(s): n/a
      File extension(s): n/a
      Macintosh file type code(s): n/a

   Person & email address to contact for further information:
      Michael B. Jones
      mbj@microsoft.com

   Intended usage:
      COMMON

   Restrictions on usage:
      none

   Author:
      Michael B. Jones
      mbj@microsoft.com

   Change controller:
      IETF

9.4.  Registration of "JWT" Type Value

   This specification registers the following "typ" header parameter
   value in the JSON Web Signature and Encryption "typ" Values registry
   established by the JSON Web Algorithms (JWA) [JWA] specification:

   "typ" header parameter value:
      "JWT"

   Abbreviation for MIME type:
      application/jwt

   Change controller:
      IETF





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   Description:
      [[ this document ]]


10.  Security Considerations

   All the security considerations in the JWS specification also apply
   to JWT, as do the JWE security considerations when encryption is
   employed.  In particular, the JWS JSON Security Considerations and
   Unicode Comparison Security Considerations apply equally to the JWT
   Claims Set in the same manner that they do to the JWS Header.


11.  Open Issues and Things To Be Done (TBD)

   The following items remain to be done in this draft:

   o  Provide an example of an encrypted JWT.


12.  References

12.1.  Normative References

   [I-D.ietf-oauth-urn-sub-ns]
              Tschofenig, H., "An IETF URN Sub-Namespace for OAuth",
              draft-ietf-oauth-urn-sub-ns-02 (work in progress),
              January 2012.

   [JWA]      Jones, M., "JSON Web Algorithms (JWA)", May 2012.

   [JWE]      Jones, M., Rescorla, E., and J. Hildebrand, "JSON Web
              Encryption (JWE)", May 2012.

   [JWS]      Jones, M., Bradley, J., and N. Sakimura, "JSON Web
              Signature (JWS)", May 2012.

   [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
              Extensions (MIME) Part One: Format of Internet Message
              Bodies", RFC 2045, November 1996.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3339]  Klyne, G., Ed. and C. Newman, "Date and Time on the
              Internet: Timestamps", RFC 3339, July 2002.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO



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              10646", STD 63, RFC 3629, November 2003.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, January 2005.

   [RFC4627]  Crockford, D., "The application/json Media Type for
              JavaScript Object Notation (JSON)", RFC 4627, July 2006.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, October 2006.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

   [USA15]    Davis, M., Whistler, K., and M. Duerst, "Unicode
              Normalization Forms", Unicode Standard Annex 15, 09 2009.

12.2.  Informative References

   [CanvasApp]
              Facebook, "Canvas Applications", 2010.

   [JSS]      Bradley, J. and N. Sakimura (editor), "JSON Simple Sign",
              September 2010.

   [MagicSignatures]
              Panzer (editor), J., Laurie, B., and D. Balfanz, "Magic
              Signatures", January 2011.

   [OASIS.saml-core-2.0-os]
              Cantor, S., Kemp, J., Philpott, R., and E. Maler,
              "Assertions and Protocol for the OASIS Security Assertion
              Markup Language (SAML) V2.0", OASIS Standard saml-core-
              2.0-os, March 2005.

   [RFC3275]  Eastlake, D., Reagle, J., and D. Solo, "(Extensible Markup
              Language) XML-Signature Syntax and Processing", RFC 3275,
              March 2002.

   [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
              Unique IDentifier (UUID) URN Namespace", RFC 4122,
              July 2005.

   [SWT]      Hardt, D. and Y. Goland, "Simple Web Token (SWT)",
              Version 0.9.5.1, November 2009.




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   [W3C.CR-xml11-20021015]
              Cowan, J., "Extensible Markup Language (XML) 1.1", W3C
              CR CR-xml11-20021015, October 2002.


Appendix A.  Relationship of JWTs to SAML Tokens

   SAML 2.0 [OASIS.saml-core-2.0-os] provides a standard for creating
   tokens with much greater expressivity and more security options than
   supported by JWTs.  However, the cost of this flexibility and
   expressiveness is both size and complexity.  In addition, SAML's use
   of XML [W3C.CR-xml11-20021015] and XML DSIG [RFC3275] only
   contributes to the size of SAML tokens.

   JWTs are intended to provide a simple token format that is small
   enough to fit into HTTP headers and query arguments in URIs.  It does
   this by supporting a much simpler token model than SAML and using the
   JSON [RFC4627] object encoding syntax.  It also supports securing
   tokens using Message Authentication Codes (MACs) and digital
   signatures using a smaller (and less flexible) format than XML DSIG.

   Therefore, while JWTs can do some of the things SAML tokens do, JWTs
   are not intended as a full replacement for SAML tokens, but rather as
   a compromise token format to be used when space is at a premium.


Appendix B.  Relationship of JWTs to Simple Web Tokens (SWTs)

   Both JWTs and Simple Web Tokens SWT [SWT], at their core, enable sets
   of claims to be communicated between applications.  For SWTs, both
   the claim names and claim values are strings.  For JWTs, while claim
   names are strings, claim values can be any JSON type.  Both token
   types offer cryptographic protection of their content: SWTs with HMAC
   SHA-256 and JWTs with a choice of algorithms, including HMAC SHA-256,
   RSA SHA-256, and ECDSA P-256 SHA-256.


Appendix C.  Acknowledgements

   The authors acknowledge that the design of JWTs was intentionally
   influenced by the design and simplicity of Simple Web Tokens [SWT]
   and ideas for JSON tokens that Dick Hardt discussed within the OpenID
   community.

   Solutions for signing JSON content were previously explored by Magic
   Signatures [MagicSignatures], JSON Simple Sign [JSS], and Canvas
   Applications [CanvasApp], all of which influenced this draft.  Dirk
   Balfanz, Yaron Y. Goland, John Panzer, and Paul Tarjan all made



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   significant contributions to the design of this specification.


Appendix D.  Document History

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

   -00

   o  Created the initial IETF draft based upon
      draft-jones-json-web-token-10 with no normative changes.


Authors' Addresses

   Michael B. Jones
   Microsoft

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


   John Bradley
   Ping Identity

   Email: ve7jtb@ve7jtb.com


   Nat Sakimura
   Nomura Research Institute

   Email: n-sakimura@nri.co.jp



















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