RFC 8693 | OAuth 2.0 Token Exchange | January 2020 |
Jones, et al. | Standards Track | [Page] |
This specification defines a protocol for an HTTP- and JSON-based Security Token Service (STS) by defining how to request and obtain security tokens from OAuth 2.0 authorization servers, including security tokens employing impersonation and delegation.¶
This is an Internet Standards Track document.¶
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.¶
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8693.¶
Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://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.¶
A security token is a set of information that facilitates the sharing of identity and security information in heterogeneous environments or across security domains. Examples of security tokens include JSON Web Tokens (JWTs) [JWT] and Security Assertion Markup Language (SAML) 2.0 assertions [OASIS.saml-core-2.0-os]. Security tokens are typically signed to achieve integrity and sometimes also encrypted to achieve confidentiality. Security tokens are also sometimes described as assertions, such as in [RFC7521].¶
A Security Token Service (STS) is a service capable of validating security tokens provided to it and issuing new security tokens in response, which enables clients to obtain appropriate access credentials for resources in heterogeneous environments or across security domains. Web Service clients have used WS-Trust [WS-Trust] as the protocol to interact with an STS for token exchange. While WS-Trust uses XML and SOAP, the trend in modern Web development has been towards RESTful (Representational State Transfer) patterns and JSON. The OAuth 2.0 Authorization Framework [RFC6749] and OAuth 2.0 Bearer Tokens [RFC6750] have emerged as popular standards for authorizing third-party applications' access to HTTP and RESTful resources. The conventional OAuth 2.0 interaction involves the exchange of some representation of resource owner authorization for an access token, which has proven to be an extremely useful pattern in practice. However, its input and output are somewhat too constrained as is to fully accommodate a security token exchange framework.¶
This specification defines a protocol extending OAuth 2.0 that enables clients to request and obtain security tokens from authorization servers acting in the role of an STS. Similar to OAuth 2.0, this specification focuses on client developer simplicity and requires only an HTTP client and JSON parser, which are nearly universally available in modern development environments. The STS protocol defined in this specification is not itself RESTful (an STS doesn't lend itself particularly well to a REST approach) but does utilize communication patterns and data formats that should be familiar to developers accustomed to working with RESTful systems.¶
A new grant type for a token exchange request and the associated specific parameters for such a request to the token endpoint are defined by this specification. A token exchange response is a normal OAuth 2.0 response from the token endpoint with a few additional parameters defined herein to provide information to the client.¶
The entity that makes the request to exchange tokens is considered the client in the context of the token exchange interaction. However, that does not restrict usage of this profile to traditional OAuth clients. An OAuth resource server, for example, might assume the role of the client during token exchange in order to trade an access token that it received in a protected resource request for a new token that is appropriate to include in a call to a backend service. The new token might be an access token that is more narrowly scoped for the downstream service or it could be an entirely different kind of token.¶
The scope of this specification is limited to the definition of a basic request-and-response protocol for an STS-style token exchange utilizing OAuth 2.0. Although a few new JWT claims are defined that enable delegation semantics to be expressed, the specific syntax, semantics, and security characteristics of the tokens themselves (both those presented to the authorization server and those obtained by the client) are explicitly out of scope, and no requirements are placed on the trust model in which an implementation might be deployed. Additional profiles may provide more detailed requirements around the specific nature of the parties and trust involved, such as whether signing and/or encryption of tokens is needed or if proof-of-possession-style tokens will be required or issued. However, such details will often be policy decisions made with respect to the specific needs of individual deployments and will be configured or implemented accordingly.¶
The security tokens obtained may be used in a number of contexts, the specifics of which are also beyond the scope of this specification.¶
One common use case for an STS (as alluded to in the previous section) is to allow a resource server A to make calls to a backend service C on behalf of the requesting user B. Depending on the local site policy and authorization infrastructure, it may be desirable for A to use its own credentials to access C along with an annotation of some form that A is acting on behalf of B ("delegation") or for A to be granted a limited access credential to C but that continues to identify B as the authorized entity ("impersonation"). Delegation and impersonation can be useful concepts in other scenarios involving multiple participants as well.¶
When principal A impersonates principal B, A is given all the rights that B has within some defined rights context and is indistinguishable from B in that context. Thus, when principal A impersonates principal B, then insofar as any entity receiving such a token is concerned, they are actually dealing with B. It is true that some members of the identity system might have awareness that impersonation is going on, but it is not a requirement. For all intents and purposes, when A is impersonating B, A is B within the context of the rights authorized by the token. A's ability to impersonate B could be limited in scope or time, or even with a one-time-use restriction, whether via the contents of the token or an out-of-band mechanism.¶
Delegation semantics are different than impersonation semantics, though the two are closely related. With delegation semantics, principal A still has its own identity separate from B, and it is explicitly understood that while B may have delegated some of its rights to A, any actions taken are being taken by A representing B. In a sense, A is an agent for B.¶
Delegation and impersonation are not inclusive of all situations. When a principal is acting directly on its own behalf, for example, neither delegation nor impersonation are in play. They are, however, the more common semantics operating for token exchange and, as such, are given more direct treatment in this specification.¶
Delegation semantics are typically expressed in a token by including information about both the
primary subject of the token as well as the actor to whom that subject has delegated some of its rights.
Such a token is sometimes referred to as a composite token because it is composed of information
about multiple subjects. Typically, in the request, the subject_token
represents the identity of the party on
behalf of whom the token is being requested while the actor_token
represents
the identity of the party to whom the access rights of the issued token are being delegated.
A composite token issued by the authorization server will contain information about both parties.
When and if a composite token is issued is at the discretion of the authorization server and
applicable policy and configuration.¶
The specifics of representing a composite token and even whether or not
such a token will be issued depend on the details of the implementation
and the kind of token. The representations of composite tokens that are
not JWTs are beyond the scope of this specification. The actor_token
request parameter, however, does provide
a means for providing information about the desired actor, and the JWT
act
claim can provide a representation of a
chain of delegation.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
This specification uses the terms "access token type", "authorization server", "client", "client identifier", "resource server", "token endpoint", "token request", and "token response" defined by OAuth 2.0 [RFC6749], and the terms "Base64url Encoding", "Claim", and "JWT Claims Set" defined by JSON Web Token (JWT) [JWT].¶
A client requests a security token by making a token request to the authorization server's token endpoint using the extension grant type mechanism defined in Section 4.5 of [RFC6749].¶
Client authentication to the authorization server is done using the normal mechanisms provided by OAuth 2.0. Section 2.3.1 of [RFC6749] defines password-based authentication of the client, however, client authentication is extensible and other mechanisms are possible. For example, [RFC7523] defines client authentication using bearer JSON Web Tokens (JWTs) [JWT]. The supported methods of client authentication and whether or not to allow unauthenticated or unidentified clients are deployment decisions that are at the discretion of the authorization server. Note that omitting client authentication allows for a compromised token to be leveraged via an STS into other tokens by anyone possessing the compromised token. Thus, client authentication allows for additional authorization checks by the STS as to which entities are permitted to impersonate or receive delegations from other entities.¶
The client makes a token exchange request to the token endpoint with an extension
grant type using the HTTP POST
method. The
following parameters are included in the HTTP request entity-body
using the application/x-www-form-urlencoded
format with a character encoding of UTF-8 as described in
Appendix B of [RFC6749].¶
urn:ietf:params:oauth:grant-type:token-exchange
indicates that a token exchange is being performed.¶
resource
parameter allows the client to indicate to the authorization server
where it intends to use the issued token by providing the location, typically as an https URL, in the
token exchange request in the same form that will be used to access that resource.
The authorization server will typically have the capability to map from a resource URI value to
an appropriate policy. The value of the resource
parameter MUST be an
absolute URI, as specified by Section 4.3 of [RFC3986],
that MAY include a query component and MUST NOT include a fragment component.
Multiple resource
parameters may be used to indicate
that the issued token is intended to be used at the multiple resources listed.
See [OAUTH-RESOURCE] for additional
background and uses of the resource
parameter.¶
resource
parameter but with the client
providing a logical name for the target service. Interpretation of the
name requires that the value be something that both the client and the
authorization server understand. An OAuth client identifier, a SAML entity
identifier [OASIS.saml-core-2.0-os], and an OpenID Connect
Issuer Identifier [OpenID.Core] are examples of things that
might be used as audience
parameter values.
However, audience
values used with a given
authorization server must be unique within that server to ensure that
they are properly interpreted as the intended type of value. Multiple
audience
parameters may be used to indicate
that the issued token is intended to be used at the multiple audiences
listed. The audience
and resource
parameters may be used together to indicate
multiple target services with a mix of logical names and resource URIs.¶
resource
or
audience
parameter.¶
subject_token
parameter.¶
actor_token
parameter.
This is REQUIRED when the actor_token
parameter
is present in the request but MUST NOT be included otherwise.¶
In processing the request, the authorization server MUST perform the appropriate validation procedures for the indicated token type and, if the actor token is present, also perform the appropriate validation procedures for its indicated token type. The validity criteria and details of any particular token are beyond the scope of this document and are specific to the respective type of token and its content.¶
In the absence of one-time-use or other semantics specific to the token type, the act of performing a token exchange has no impact on the validity of the subject token or actor token. Furthermore, the exchange is a one-time event and does not create a tight linkage between the input and output tokens, so that (for example) while the expiration time of the output token may be influenced by that of the input token, renewal or extension of the input token is not expected to be reflected in the output token's properties. It may still be appropriate or desirable to propagate token-revocation events. However, doing so is not a general property of the STS protocol and would be specific to a particular implementation, token type, or deployment.¶
When requesting a token, the client can indicate the desired target
service(s) where it intends to use that token by way of the audience
and resource
parameters as well as indicate the
desired scope of the requested token using the scope
parameter.
The semantics of such a request are that the client is asking for a token with the requested
scope that is usable at all the requested target services. Effectively, the requested access rights of
the token are the Cartesian product of all the scopes at all the target services.¶
An authorization server may be unwilling or unable to fulfill any token request, but the likelihood
of an unfulfillable request is significantly higher when very broad access rights are being solicited.
As such, in the absence of specific knowledge about the relationship of systems in a deployment,
clients should exercise discretion in the breadth of the access requested, particularly the
number of target services. An authorization server can use the invalid_target
error code, defined in Section 2.2.2, to inform a client that it requested access to
too many target services simultaneously.¶
The authorization server responds to a token exchange request with a normal OAuth 2.0 response from the token endpoint, as specified in Section 5 of [RFC6749]. Additional details and explanation are provided in the following subsections.¶
If the request is valid and meets all policy and other criteria of the authorization server, a successful token response is constructed by adding the following parameters to the entity-body of the HTTP response using the "application/json" media type, as specified by [RFC8259], and an HTTP 200 status code. The parameters are serialized into a JavaScript Object Notation (JSON) structure by adding each parameter at the top level. Parameter names and string values are included as JSON strings. Numerical values are included as JSON numbers. The order of parameters does not matter and can vary.¶
access_token
parameter from
Section 5.1 of [RFC6749] is used here to carry the requested
token, which allows this token exchange protocol to use the existing OAuth 2.0 request
and response constructs defined for the token endpoint.
The identifier access_token
is used for historical
reasons and the issued token need not be an OAuth access token.¶
Bearer
, as specified in [RFC6750],
indicates that the issued security token is a bearer token and the client
can simply present it as is without any additional proof of eligibility
beyond the contents of the token itself. Note that the meaning of this
parameter is different from the meaning of the issued_token_type
parameter, which declares the
representation of the issued security token; the term "token type" is more
typically used to mean the structural or syntactical representation of the security token, as it is in all *_token_type
parameters in this specification. If the
issued token is not an access token or usable as an access token, then the
token_type
value N_A
is used to indicate that an OAuth 2.0 token_type
identifier is not applicable in that context.¶
urn:ietf:params:oauth:grant-type:token-exchange
grant type requests.¶
If the request itself is not valid or if either the subject_token
or actor_token
are invalid for any reason, or are
unacceptable based on policy, the authorization server MUST construct an
error response, as specified in Section 5.2 of [RFC6749].
The value of the error
parameter MUST be the
invalid_request
error code.¶
If the authorization server is unwilling or unable to issue a token for any target service
indicated by the resource
or audience
parameters,
the invalid_target
error code SHOULD be used in the error response.¶
The authorization
server MAY include additional information regarding the reasons for the error
using the error_description
as discussed in Section 5.2 of [RFC6749].¶
Other error codes may also be used, as appropriate.¶
The following example demonstrates a hypothetical token exchange in which an OAuth resource server assumes the role of the client during the exchange. It trades an access token, which it received in a protected resource request, for a new token that it will use to call to a backend service (extra line breaks and indentation in the examples are for display purposes only).¶
Figure 1 shows the resource server receiving a protected resource request containing an OAuth access token in the Authorization header, as specified in Section 2.1 of [RFC6750].¶
In Figure 2, the resource server assumes the role of
client for the token exchange, and the access token from the request in
Figure 1 is sent to the authorization server using a
request as specified in Section 2.1. The value of the subject_token
parameter carries the access token, and
the value of the subject_token_type
parameter
indicates that it is an OAuth 2.0 access token. The resource server, acting
in the role of the client, uses its identifier and secret to authenticate to
the authorization server using the HTTP Basic authentication scheme. The
resource
parameter indicates the location of the
backend service, <https://backend.example.com/api>, where the issued token
will be used.¶
The authorization server validates the client credentials and the
subject_token
presented in the token
exchange request. From the resource
parameter, the authorization server is able to determine the
appropriate policy to apply to the request and issues a token
suitable for use at <https://backend.example.com>.
The access_token
parameter of the
response shown in Figure 3 contains the new token, which is itself a bearer OAuth
access token that is valid for one minute. The token happens to be
a JWT; however, its structure and format are opaque to
the client, so the issued_token_type
indicates only that it is an access token.¶
The resource server can then use the newly acquired access token in making a request to the backend server as illustrated in Figure 4.¶
Additional examples can be found in Appendix A.¶
Several parameters in this specification utilize an identifier as the value to
describe the token in question.
Specifically, they are the
requested_token_type
,
subject_token_type
, and actor_token_type
parameters of the request and the issued_token_type
member of the response.
Token type identifiers are URIs.
Token exchange can work with both tokens issued by other parties and tokens from
the given authorization server. For the former, the token type identifier indicates
the syntax (e.g., JWT or SAML 2.0) so the authorization server can parse it; for the latter, it indicates
what the given authorization server issued it for (e.g., access_token
or refresh_token
).¶
The following token type identifiers are defined by this specification. Other URIs MAY be used to indicate other token types.¶
The value urn:ietf:params:oauth:token-type:jwt
, which is defined in
Section 9 of [JWT], indicates that the token is a JWT.¶
The distinction between an access token and a JWT is subtle.
An access token represents a delegated authorization decision, whereas JWT is a token format.
An access token can be formatted as a JWT but doesn't necessarily have to be. And a
JWT might well be an access token, but not all JWTs are access tokens.
The intent of this specification is that urn:ietf:params:oauth:token-type:access_token
be an indicator that the token is a typical OAuth access token issued by the authorization server in question, opaque to the client,
and usable the same manner as any other access token obtained from that authorization server.
(It could well be a JWT, but the client isn't and needn't be aware of that fact.)
Whereas, urn:ietf:params:oauth:token-type:jwt
is to indicate specifically that a JWT is
being requested or sent (perhaps in a cross-domain use case where the JWT is used as an authorization grant to
obtain an access token from a different authorization server as is facilitated by [RFC7523]).¶
Note that for tokens that are binary in nature, the URI used for conveying them needs to be associated with the semantics of a base64 or other encoding suitable for usage with HTTP and OAuth.¶
It is useful to have defined mechanisms to express delegation within a token as well as to express authorization to delegate or impersonate. Although the token exchange protocol described herein can be used with any type of token, this section defines claims to express such semantics specifically for JWTs and in an OAuth 2.0 Token Introspection [RFC7662] response. Similar definitions for other types of tokens are possible but beyond the scope of this specification.¶
Note that the claims not established herein but used in examples and descriptions,
such as iss
, sub
,
exp
, etc., are defined by [JWT].¶
The act
(actor) claim provides a means
within a JWT to express that delegation has occurred and identify the
acting party to whom authority has been delegated. The act
claim value is a JSON object, and members in
the JSON object are claims that identify the actor. The claims that
make up the act
claim identify and possibly
provide additional information about the actor. For example, the
combination of the two claims iss
and sub
might be necessary to uniquely identify an
actor.¶
However, claims within the act
claim pertain only to the identity of the actor
and are not relevant to the validity of the containing JWT in the same manner as the top-level claims.
Consequently, non-identity claims (e.g., exp
, nbf
,
and aud
) are not meaningful when used within an
act
claim and are therefore not used.¶
Figure 5 illustrates the act
(actor) claim within a JWT Claims Set. The
claims of the token itself are about user@example.com while the act
claim indicates that admin@example.com is the
current actor.¶
A chain of delegation can be expressed by nesting one act
claim within
another. The outermost act
claim represents the current actor while nested
act
claims represent prior actors. The least recent actor is the most deeply
nested. The nested act
claims
serve as a history trail that connects the initial request and subject
through the various delegation steps undertaken before reaching the
current actor. In this sense, the current actor is considered to
include the entire authorization/delegation history, leading naturally
to the nested structure described here.¶
For the purpose of applying access control policy, the consumer of a token MUST only consider the token's
top-level claims and the party identified as the current actor by the act
claim. Prior actors identified by any nested act
claims are
informational only and are not to be considered in access control decisions.¶
The following example in Figure 6 illustrates nested act
(actor) claims within a JWT Claims Set.
The claims of the token itself are about user@example.com while the act
claim indicates
that the system <https://service16.example.com> is the current actor and <https://service77.example.com> was a prior actor.
Such a token might come about as the result of service16 receiving a token in a call from service77
and exchanging it for a token suitable to call service26 while the authorization server
notes the situation in the newly issued token.¶
When included as a top-level member of an OAuth token introspection response, act
has the same semantics and format as the claim of the same name.¶
The value of the scope
claim is a
JSON string containing a space-separated list of
scopes associated with the token, in the format described in
Section 3.3 of [RFC6749].¶
Figure 7 illustrates the scope
claim within a JWT Claims Set.¶
OAuth 2.0 Token Introspection [RFC7662] already defines the scope
parameter to convey the scopes associated with the token.¶
The client_id
claim carries the
client identifier of the OAuth 2.0 [RFC6749] client that
requested the token.¶
The following example in Figure 8 illustrates the client_id
claim within a JWT Claims Set
indicating an OAuth 2.0 client with "s6BhdRkqt3" as its identifier.¶
OAuth 2.0 Token Introspection [RFC7662] already defines the client_id
parameter as the client identifier for the OAuth 2.0 client that requested the token.¶
The may_act
claim makes a statement that one party is authorized to
become the actor and act on behalf of another party.
The claim might be used, for example, when a subject_token
is
presented to the token endpoint in a token exchange request and
may_act
claim in the subject token can be used by the authorization
server to determine whether the client (or party identified in the
actor_token
) is authorized to engage in the requested delegation or
impersonation.
The claim value is a JSON object, and members in the JSON object are claims that identify the party that
is asserted as being eligible to act for the party identified by
the JWT containing the claim.
The claims that make up the may_act
claim identify and possibly provide additional information about the authorized actor.
For example, the combination of the two claims iss
and sub
are sometimes necessary to uniquely identify an authorized actor,
while the email
claim might be used to provide additional useful information about
that party.¶
However, claims within the may_act
claim pertain only to the identity of that party
and are not relevant to the validity of the containing JWT
in the same manner as top-level claims.
Consequently, claims such as exp
, nbf
, and
aud
are not meaningful when used within a may_act
claim and are therefore not used.¶
Figure 9 illustrates the may_act
claim within a JWT Claims Set.
The claims of the token itself are about user@example.com while the may_act
claim indicates
that admin@example.com is authorized to act on behalf of user@example.com.¶
When included as a top-level member of an OAuth token introspection response, may_act
has the same semantics and format as the claim of the same name.¶
Much of the guidance from Section 10 of [RFC6749], the Security Considerations in The OAuth 2.0 Authorization Framework, is also applicable here. Furthermore, [RFC6819] provides additional security considerations for OAuth, and [OAUTH-SECURITY] has updated security guidance based on deployment experience and new threats that have emerged since OAuth 2.0 was originally published.¶
All of the normal security issues that are discussed in [JWT], especially in relationship to comparing URIs and dealing with unrecognized values, also apply here.¶
In addition, both delegation and impersonation introduce unique
security issues. Any time one principal is delegated the rights of
another principal, the potential for abuse is a concern. The use of
the scope
claim (in addition to other
typical constraints such as a limited token lifetime) is suggested to
mitigate potential for such abuse, as it restricts the contexts in
which the delegated rights can be exercised.¶
Tokens employed in the context of the functionality described herein may contain privacy-sensitive information and, to prevent disclosure of such information to unintended parties, MUST only be transmitted over encrypted channels, such as Transport Layer Security (TLS). In cases where it is desirable to prevent disclosure of certain information to the client, the token MUST be encrypted to its intended recipient. Deployments SHOULD determine the minimally necessary amount of data and only include such information in issued tokens. In some cases, data minimization may include representing only an anonymous or pseudonymous user.¶
IANA has registered the following values in the "OAuth URI" subregistry of the "OAuth Parameters" registry [IANA.OAuth.Parameters]. The "OAuth URI" subregistry was established by [RFC6755].¶
IANA has registered the following values in the "OAuth Parameters" subregistry of the "OAuth Parameters" registry [IANA.OAuth.Parameters]. The "OAuth Parameters" subregistry was established by [RFC6749].¶
IANA has registered the following access token type in the "OAuth Access Token Types" subregistry of the "OAuth Parameters" registry [IANA.OAuth.Parameters]. The "OAuth Access Token Types" subregistry was established by [RFC6749].¶
IANA has registered the following Claims in the "JSON Web Token Claims" subregistry of the "JSON Web Token (JWT)" registry [IANA.JWT]. The "JSON Web Token Claims" subregistry was established by [JWT].¶
IANA has registered the following values in the "OAuth Token Introspection Response" registry of the "OAuth Parameters" registry [IANA.OAuth.Parameters]. The "OAuth Token Introspection Response" registry was established by [RFC7662].¶
Two example token exchanges are provided in the following sections illustrating impersonation and delegation, respectively (with extra line breaks and indentation for display purposes only).¶
In the following token exchange request, a client is requesting a token
with impersonation semantics (delegation is impossible with only a subject_token
and no actor_token
).
The client tells the authorization server that it needs a token for use at
the target service with the logical name
urn:example:cooperation-context
.¶
The subject_token
in the prior request is a JWT, and
the decoded JWT Claims Set is shown here. The JWT is
intended for consumption by the authorization server within a specific time window.
The subject of the JWT (bdc@example.net
) is
the party on behalf of whom the new token is being requested.¶
The access_token
parameter of the token exchange
response shown below contains the new token that the client requested.
The other parameters of the response indicate that the token is a bearer access token
that expires in an hour.¶
The decoded JWT Claims Set of the issued token is shown below. The new JWT is
issued by the authorization server and intended for consumption by a system entity
known by the logical name urn:example:cooperation-context
any time before its expiration.
The subject (sub
) of the JWT
is the same as the subject the token used to make the request,
which effectively enables the client to impersonate that subject
at the system entity known by the logical name of
urn:example:cooperation-context
by using the token.¶
In the following token exchange request, a client is requesting a token
and providing both a subject_token
and an actor_token
.
The client tells the authorization server that it needs a token for use at
the target service with the logical name
urn:example:cooperation-context
. Policy at the
authorization server dictates that the issued token be a composite.¶
The subject_token
in the prior request is a JWT, and
the decoded JWT Claims Set is shown here. The JWT is
intended for consumption by the authorization server
before a specific expiration time.
The subject of the JWT
(user@example.net
) is
the party on behalf of whom the new token is being requested.¶
The actor_token
in the prior request is a JWT, and
the decoded JWT Claims Set is shown here. This JWT is also
intended for consumption by the authorization server
before a specific expiration time.
The subject of the JWT
(admin@example.net
) is
the actor that will wield the security token being requested.¶
The access_token
parameter of the token exchange
response shown below contains the new token that the client requested.
The other parameters of the response indicate that the token is a JWT
that expires in an hour and that the access token type is not applicable
since the issued token is not an access token.¶
The decoded JWT Claims Set of the issued token is shown below. The new JWT is
issued by the authorization server and intended for consumption by a system entity
known by the logical name
urn:example:cooperation-context
any time before its expiration.
The subject (sub
)
of the JWT
is the same as the subject of
the subject_token
used to make the request.
The actor (act
) of the JWT is the same as the subject
of the actor_token
used to make the request.
This indicates delegation and identifies
admin@example.net
as the current actor to whom authority
has been delegated to act on behalf of user@example.net
.¶
This specification was developed within the OAuth Working Group, which includes dozens of active and dedicated participants. It was produced under the chairmanship of Hannes Tschofenig, Derek Atkins, and Rifaat Shekh-Yusef, with Kathleen Moriarty, Stephen Farrell, Eric Rescorla, Roman Danyliw, and Benjamin Kaduk serving as Security Area Directors.¶
The following individuals contributed ideas, feedback, and wording to this specification: Caleb Baker, Vittorio Bertocci, Mike Brown, Thomas Broyer, Roman Danyliw, William Denniss, Vladimir Dzhuvinov, Eric Fazendin, Phil Hunt, Benjamin Kaduk, Jason Keglovitz, Torsten Lodderstedt, Barry Leiba, Adam Lewis, James Manger, Nov Matake, Matt Miller, Hilarie Orman, Matthew Perry, Eric Rescorla, Justin Richer, Adam Roach, Rifaat Shekh-Yusef, Scott Tomilson, and Hannes Tschofenig.¶