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Security Web Authorization Protocol authorization abac authzen openid This specification defines a profile of OAuth 2.0 Rich Authorization Requests leveraging the OpenID AuthZEN authorization request/response formats within the authorization_details JSON object. Authorization servers and resource servers from different vendors can leverage this profile to request and receive relevant authorization decisions from an AuthZEN-compatible PDP in an interoperable manner. About This Document The latest revision of this draft can be found at . Status information for this document may be found at . Discussion of this document takes place on the Web Authorization Protocol Working Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at .

Introduction OpenID AuthZEN is a Working Group under the OpenID Foundation which aims to increase interoperability and standardization in the authorization realm. In particular, AuthZEN aims to:

• build standards-based authorization APIs
• define standard design patterns for authorization
• produce educational material to help raise awareness of externalized authorization.

The aim of this profile is to define an AuthZEN-conformant profile of the OAuth 2.0 Rich Authorization Requests . introduces a new parameter authorization_details that allows clients to specify their fine-grained authorization requirements using the expressiveness of JSON data structures. This specification introduces a more structured format for the authorization_details parameter. The new format is also JSON as a result of which this specification is conformant with and is merely a stricter profile. For example the authorization request for a credit transfer mentioned in would now be structured as follows

Source Authorization Request

Using AuthZEN as a format for authorization_details will increase the usability and the interoperability of . In particular, it will be possible for the AS to forward the contents of the authorization_details parameter to an AuthZEN-conformant Policy Decision Point (PDP).

Conventions and Definitions 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 when, and only when, they appear in all capitals, as shown here. This specification uses the terms "access token", "refresh token", "authorization server" (AS), "resource server" (RS), "authorization endpoint", "authorization request", "authorization response", "token endpoint", "grant type", "access token request", "access token response", and "client" defined by "The OAuth 2.0 Authorization Framework" . This specification uses the terms "PDP" and "PEP" defined by and .

Request Parameter authorization_details In , the request parameter authorization_details contains, in JSON notation, an array of objects. Each JSON object contains the data to specify the authorization requirements for a certain type of resource. This specification defines the format for each one of these objects such that it conforms to and . groups JSON datastructures into 4 JSON objects:

• subject: A Subject is the user or robotic principal about whom the Authorization API is being invoked. The Subject may be requesting access at the time the Authorization API is invoked.
• resource: A Resource is the target of an access request. It is a JSON () object that is constructed similar to a Subject entity.
• action: An Action is the type of access that the requester intends to perform. Action is a JSON () object that contains at least a name field.
• context: The Context object is a set of attributes that represent environmental or contextual data about the request such as time of day. It is a JSON () object.

Note: the aforementioned is indicative only. Always refer to for the formal definition of each element.

authorization_details Structure Because type is REQUIRED, the new authorization_details structure is as follows:

• type: An identifier for the authorization details type as a string. The value for this profile is "authzen_evaluation" or "authzen_evaluations", corresponding to the AuthZEN API being invoked. The value is case-insensitive. This field is REQUIRED.
• request: this field contains the entire AuthZEN-conformant authorization request. This field is REQUIRED.

Authorization Details Types This profile declares a new value for the type field as stated in the previous section. The value for this profile is "authzen_evaluation" or "authzen_evaluations". This indicates there will be another field called request and its value will be an AuthZEN-conformant authorization request. The "authzen_evaluation" or "authzen_evaluations" types also indicate that the authorization response should contain a response field containing the authorization response matching the request or requests. The response field will be an AuthZEN-conformant authorization response (see below). AuthZEN also defines a type field in the Subject and Resource categories. This field is meant to describe the type of user and/or resource required.

Common Data Fields No field other than type and request shall be allowed in authorization_details when the type is authzen_evaluation or authzen_evaluations. All other fields such as the ones mentioned in shall be inserted inside the AuthZEN request in the relevant object (Subject, Resource, Action, or Context).

Authorization Request Conformant to , the authorization_details authorization request parameter can be used to specify authorization requirements in all places where the scope parameter is used for the same purpose, examples include:

• authorization requests as specified in
• device authorization requests as specified in
• backchannel authentication requests as defined in

Parameter encoding follows the exact same rules as .

Example (non-normative)

Source Authorization Request

Support for Multiple Authorization Requests supports a profile that allows the expression of multiple authorization requests in a single JSON object. As a result, this profile recommends the use of a single authorization_details object containing boxcarred requests as described in when possible and the use of the authorization_details array otherwise.

Example (non-normative) This example is based on the one in under section 3. Authorization Request.

Authorization Responses Whereas doesn't specify any extensions for authorization_details responses, standardizes the responses expected from the PDP. An AuthZEN response is therefore expected for all AuthZEN requests. This response can be used by authorization clients directly or by the AS during token creation. In particular, authorization response can be used in conjunction with any user-consent flow. The new authorization_details response structure is as follows:

• type: The value of this field is expected to be "authzen_evaluation" for a single authorization request, or "authzen_evaluations" for multiple (Boxcarred) evalution requests. This field is REQUIRED.
• response: This field contains the entire AuthZEN-conformant authorization response. This field is REQUIRED.

Single-response Example (non-normative)

Source Authorization Response

Boxcarred-response Example (non-normative) Using responses as described in , a response to the boxcarred example of the multi-authorization requests section above could be:

Source Authorization Response

Security Considerations The Security Considerations of , , , and all apply.

IANA Considerations This document has no IANA actions.

References Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. The OAuth 2.0 authorization framework enables a third-party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf. This specification replaces and obsoletes the OAuth 1.0 protocol described in RFC 5849. [STANDARDS-TRACK] This specification defines a method for a protected resource to query an OAuth 2.0 authorization server to determine the active state of an OAuth 2.0 token and to determine meta-information about this token. OAuth 2.0 deployments can use this method to convey information about the authorization context of the token from the authorization server to the protected resource. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format. It was derived from the ECMAScript Programming Language Standard. JSON defines a small set of formatting rules for the portable representation of structured data. This document removes inconsistencies with other specifications of JSON, repairs specification errors, and offers experience-based interoperability guidance. This specification defines a metadata format that an OAuth 2.0 client can use to obtain the information needed to interact with an OAuth 2.0 authorization server, including its endpoint locations and authorization server capabilities. The OAuth 2.0 device authorization grant is designed for Internet- connected devices that either lack a browser to perform a user-agent- based authorization or are input constrained to the extent that requiring the user to input text in order to authenticate during the authorization flow is impractical. It enables OAuth clients on such devices (like smart TVs, media consoles, digital picture frames, and printers) to obtain user authorization to access protected resources by using a user agent on a separate device. This document specifies a new parameter that is used to carry fine-grained authorization data in OAuth messages. Aserto Axiomatics SGNL Aserto Axiomatics SGNL Informative References Axiomatics AB NIST NIST

Acknowledgments We would like to thank members of the OpenID AuthZEN Working Group for their valuable feedback during the preparation of this specification. In particular our thanks go to Gerry Gebel and Allan Foster. We would also like to thank Justin Richer and Pieter Kasselman for their guidance on this spec and the overall IETF process.