RFC 7522: Security Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants | RFC Editor

Skip to content Primary navigationThe RFC SeriesFor AuthorsAbout UsHomeRFC 7522 View as: Plain Text, Compact HTML Info RFC 7522: Security Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grantsfederated authenticationOAuthMay 2015. B. Campbell, C. Mortimore, M. JonesProposed StandardSubscribe20 subscribed Add to Set Added to 1 Set Read aloud This RFC was updated, see RFC 10070.Internet Engineering Task Force (IETF) B. Campbell Request for Comments: 7522 Ping Identity Category: Standards Track C. Mortimore ISSN: 2070-1721 Salesforce M. Jones Microsoft May 2015 Security Assertion Markup Language (SAML) 2.0 Profile for OAuth 2.0 Client Authentication and Authorization Grants Abstract This specification defines the use of a Security Assertion Markup Language (SAML) 2.0 Bearer Assertion as a means for requesting an OAuth 2.0 access token as well as for client authentication. Status of This Memo 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 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7522. Copyright Notice Copyright (c) 2015 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 (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. Campbell, et al. Standards Track [Page 1] RFC 7522 OAuth SAML Assertion Profiles May 2015 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2. HTTP Parameter Bindings for Transporting Assertions . . . . . 4 2.1. Using SAML Assertions as Authorization Grants . . . . . . 4 2.2. Using SAML Assertions for Client Authentication . . . . . 5 3. Assertion Format and Processing Requirements . . . . . . . . 6 3.1. Authorization Grant Processing . . . . . . . . . . . . . 8 3.2. Client Authentication Processing . . . . . . . . . . . . 9 4. Authorization Grant Example . . . . . . . . . . . . . . . . . 9 5. Interoperability Considerations . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8.1. Sub-Namespace Registration of urn:ietf:params:oauth:grant-type:saml2-bearer . . . . . . 12 8.2. Sub-Namespace Registration of urn:ietf:params:oauth:client-assertion-type:saml2-bearer 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . 13 9.2. Informative References . . . . . . . . . . . . . . . . . 14 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction The Security Assertion Markup Language (SAML) 2.0 [OASIS.saml-core-2.0-os] is an XML-based framework that allows identity and security information to be shared across security domains. The SAML specification, while primarily targeted at providing cross domain Web browser single sign-on (SSO), was also designed to be modular and extensible to facilitate use in other contexts. The Assertion, an XML security token, is a fundamental construct of SAML that is often adopted for use in other protocols and specifications. (Some examples include [OASIS.WSS-SAMLTokenProfile] and [OASIS.WS-Fed].) An Assertion is generally issued by an Identity Provider and consumed by a Service Provider that relies on its content to identify the Assertion's subject for security-related purposes. The OAuth 2.0 Authorization Framework [RFC6749] 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 Campbell, et al. Standards Track [Page 2] RFC 7522 OAuth SAML Assertion Profiles May 2015 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. "Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants" [RFC7521] is an abstract extension to OAuth 2.0 that provides a general framework for the use of assertions as client credentials and/or authorization grants with OAuth 2.0. This specification profiles the OAuth Assertion Framework [RFC7521] to define an extension grant type that uses a SAML 2.0 Bearer Assertion to request an OAuth 2.0 access token as well as for use as client credentials. The format and processing rul