JSON Web Token (JWT) Bearer Token Profiles for OAuth 2.0Microsoftmbj@microsoft.comhttp://self-issued.info/Ping Identity Corp.brian.d.campbell@gmail.comSalesforcecmortimore@salesforce.com
Security
OAuth Working GroupOAuthJWTAssertionTokenSecurity TokenThis specification defines the use of a JSON Web Token (JWT) Bearer Token as a means for requesting an OAuth 2.0 access
token as well as for use as a means of client authentication.
JSON Web Token (JWT)
is a JavaScript Object Notation (JSON)
based security token encoding that enables
identity and security information to be shared across security
domains.
A security token is generally issued by an identity provider
and consumed by a relying party that relies on its content to
identify the token's subject for security related purposes.
The OAuth 2.0 Authorization Framework
provides
a method for making authenticated HTTP requests to a resource using an access token.
Access tokens are issued to third-party clients by an
authorization server (AS) with the (sometimes implicit) approval of the resource owner.
In OAuth, an authorization grant is an abstract term used to describe
intermediate credentials that represent the resource owner
authorization. An authorization grant is used by the client to obtain an access token.
Several authorization grant types are defined to support a wide range
of client types and user experiences.
OAuth also allows for the definition of new extension grant types
to support additional clients or to provide a bridge between OAuth and other trust frameworks.
Finally, OAuth allows the definition of additional authentication mechanisms to be used by clients when interacting with the authorization server.
The Assertion Framework for OAuth 2.0 is an abstract extension to OAuth 2.0 that provides a general
framework for the use of Assertions (a.k.a. Security Tokens) as client credentials and/or authorization grants with OAuth 2.0.
This specification profiles the Assertion Framework for OAuth 2.0 to define an extension grant type that uses a JSON Web Token (JWT) Bearer Token to
request an OAuth 2.0 access token as well as for use as client credentials.
The format and processing rules for the JWT defined in this specification are intentionally similar,
though not identical, to those in the closely related
SAML 2.0 Bearer Assertion Profiles for OAuth 2.0.
This document defines how a JSON Web Token (JWT) Bearer Token can be used to request an access token when a client wishes to utilize an existing trust
relationship, expressed through the semantics of (and digital signature calculated over) the JWT,
without a direct user approval step at the authorization server. It also defines how a JWT can be used as a client authentication mechanism.
The use of a security token for client
authentication is orthogonal to and separable from using a security token as an
authorization grant. They can be used either in combination or separately.
Client authentication using a JWT is nothing more than an alternative way for a client to authenticate
to the token endpoint and must be used in conjunction with some grant type to form a complete and
meaningful protocol request. JWT authorization grants may be used with or without client authentication
or identification. Whether or not client authentication is needed in conjunction with a JWT authorization
grant, as well as the supported types of client authentication, are policy decisions at the discretion of the authorization server.
The process by which the client obtains the JWT, prior to exchanging it with the authorization server or using it for client authentication, is out of scope.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.
Unless otherwise noted, all the protocol parameter names and values are case sensitive.
All terms are as defined in
The OAuth 2.0 Authorization Framework,
Assertion Framework for OAuth 2.0, and
JSON Web Token (JWT).
The Assertion Framework for OAuth 2.0 defines generic HTTP parameters for transporting Assertions (a.k.a. Security Tokens) during interactions with a token endpoint.
This section defines the values of those parameters for use with JWT Bearer Tokens.
To use a JWT Bearer Token as an authorization grant, use the following parameter values and encodings.The value of the grant_type parameter MUST be
urn:ietf:params:oauth:grant-type:jwt-bearer.
The value of the assertion parameter
MUST contain a single JWT.
The following non-normative example demonstrates an Access Token Request with a JWT as an authorization grant
(with extra line breaks for display purposes only):To use a JWT Bearer Token for client authentication, use the following parameter values and encodings.The value of the client_assertion_type parameter MUST be
urn:ietf:params:oauth:client-assertion-type:jwt-bearer.
The value of the client_assertion parameter
MUST contain a single JWT.
The following non-normative example demonstrates client
authentication using a JWT during the presentation of an authorization code grant in an
Access Token Request
(with extra line breaks for display purposes only):
In order to issue an access token response as described in
The OAuth 2.0 Authorization Framework
or to rely on a JWT for client authentication,
the authorization server MUST validate the JWT according to the criteria below.
Application of additional restrictions and policy are at the discretion of the authorization server.
The JWT MUST contain an iss
(issuer) claim that contains a unique identifier for the
entity that issued the JWT.
The JWT MUST contain a prn
(principal) claim identifying the subject of the transaction.
The principal MAY identify the resource owner for
whom the access token is being requested.
For client authentication, the principal MUST be the client_id of the OAuth client. When using
a JWT as an authorization grant, the principal SHOULD identify
an authorized accessor for whom the access token is being requested (typically the resource owner, or an authorized delegate).
The JWT MUST contain an aud
(audience) claim containing a URI reference that
identifies the
authorization server, or the service provider principal entity of its controlling domain, as an
intended audience. The token endpoint URL of the authorization server MAY be used as an
acceptable value for an aud element.
The authorization server MUST verify that it is an intended audience for
the JWT.
The JWT MUST contain an exp
(expiration) claim that limits the time window during
which the JWT can be used. The authorization server
MUST verify that the expiration time has not passed,
subject to allowable clock skew between systems. The
authorization server MAY reject JWTs with an exp claim value that is
unreasonably far in the future.
The JWT MAY contain an nbf
(not before) claim that identifies the time before which
the token MUST NOT be accepted for processing.
The JWT MAY contain an iat
(issued at) claim that identifies the time at which the
JWT was issued. The authorization server MAY reject JWTs
with an iat claim value that is
unreasonably far in the past.
The JWT MAY contain a jti
(JWT ID) claim that provides a unique identifier for
the token.
The authorization server MAY ensure that JWTs are not
replayed by maintaining the set of used
jti values for the length of
time for which the JWT would be considered valid based
on the applicable exp instant.
The JWT MAY contain other claims.
The JWT MUST be digitally signed by the issuer and the
authorization server MUST verify the signature.
The authorization server MUST verify that the JWT is
valid in all other respects per
JSON Web Token (JWT).
If present, the authorization server MUST also validate the client credentials.If the JWT is not valid, or the current time is not within the token's valid time window for use, the
authorization server MUST construct an error response as defined in
OAuth 2.0.
The value of the error parameter MUST be the
invalid_grant error code. The authorization server
MAY include additional information regarding the reasons the JWT was considered invalid using the
error_description or error_uri parameters.
If the client JWT is not valid, or its subject confirmation requirements cannot be met, the
authorization server MUST construct an error response as defined in
OAuth 2.0.
The value of the error parameter MUST be the
invalid_client error code. The authorization server
MAY include additional information regarding the reasons the JWT was considered invalid using the
error_description or error_uri parameters.
Though non-normative, the following examples illustrate what a conforming JWT and access token request would look like.
No additional security considerations apply beyond those described within
The OAuth 2.0 Authorization Framework,
the Assertion Framework for OAuth 2.0,
and the JSON Web Token (JWT) specification.
This specification registers the value
grant-type:jwt-bearer in the
IANA urn:ietf:params:oauth registry established in
An IETF URN Sub-Namespace for OAuth.
URN: urn:ietf:params:oauth:grant-type:jwt-bearerCommon Name: JWT Bearer Token Grant Type Profile for OAuth 2.0Change controller: IETFSpecification Document: [[this document]]
This specification registers the value
client-assertion-type:jwt-bearer in the
IANA urn:ietf:params:oauth registry established in
An IETF URN Sub-Namespace for OAuth.
URN: urn:ietf:params:oauth:client-assertion-type:jwt-bearerCommon Name: JWT Bearer Token Profile for OAuth 2.0 Client Authentication Change controller: IETFSpecification Document: [[this document]]JSON Web Token (JWT)Microsoftmbj@microsoft.comhttp://self-issued.info/Ping Identityve7jtb@ve7jtb.comNomura Research Instituten-sakimura@nri.co.jp
This profile was derived from
SAML 2.0 Bearer Assertion Profiles for OAuth 2.0
by Brian Campbell and Chuck Mortimore.
[[ to be removed by the RFC editor before publication as an RFC ]]
-03
Reference RFC 6749 and RFC 6755.
-02
Add more text to intro explaining that an assertion/JWT grant type can be used with or without client
authentication/identification and that client assertion/JWT authentication is nothing more than an alternative way for a client to authenticate to the token endpointAdd examples to Sections 2.1 and 2.2Update references
-01
Tracked specification name changes:
"The OAuth 2.0 Authorization Protocol" to "The OAuth 2.0 Authorization Framework" and
"OAuth 2.0 Assertion Profile" to "Assertion Framework for OAuth 2.0".
Merged in changes between draft-ietf-oauth-saml2-bearer-11
and draft-ietf-oauth-saml2-bearer-13.
All changes were strictly editorial.
-00
Created the initial IETF draft based upon
draft-jones-oauth-jwt-bearer-04 with no normative
changes.