Application Bridging for Federated Access Beyond web (abfab) ------------------------------------------------------------ Charter Last Modified: 2011-03-31 Current Status: Active Working Group Chair(s): Leif Johansson Klaas Wierenga Security Area Director(s): Stephen Farrell Sean Turner Security Area Advisor: Stephen Farrell Mailing Lists: General Discussion:abfab@ietf.org To Subscribe: https://www.ietf.org/mailman/listinfo/abfab Archive: http://www.ietf.org/mail-archive/web/abfab/ Description of Working Group: Problem Statement Federated identity facilitates the controlled sharing of information about principals, commonly across organisational boundaries. This avoids redundant registration of principals who operate in multiple domains, reducing administrative overheads and improving usability while addressing privacy-related concerns and regulatory and statutory requirements of some jurisdictions. A number of such mechanisms are in use for the Web. This working group will specify a federated identity mechanism for use by other Internet protocols not based on HTML/HTTP, such as for instance IMAP, XMPP, SSH and NFS. The design will combine existing protocols, specifically the Extensible Authentication Protocol (EAP - RFC 3748), Authentication, Authorization and Account Protocols (RADIUS - RFC 2865 and Diameter - RFC 3588), and the Security Assertion Markup Language (SAML). Specifically EAP will be used to authenticate the subject to a trusted party, AAA (RADIUS and Diameter) will be used to authenticate and convey information from that party to a relying party and SAML and SAML message formats are used to carry subject information that can be used for authorization and personalization by a relying party. Any change in the choices for these three technical roles is out of scope for this charter. Constraints ----------- Initially the working group will focus on using GSS-API (RFC2743) as a mechanism for integrating the developed solution for federated identity into application protocols but other technologies for application interface are in scope of the working group and may be adopted as deliverables subject to the normal IETF consensus and (re)charter process. In order to be usable in all current Internet protocols, GSS-API mechanism must provide the following features: mutual authentication, key confirmation, host-based service naming, per-message tokens ("security layers") and channel binding. Support for Pseudo Random Function (PRF) is desirable, and generally feasible whenever per-message tokens are supported. As a result, all of those features are required for GSS-API mechanisms produced by this WG. Note also that some of these requirements derive from SASL (RFC 4422) applications, which can use GSS- API mechanisms through GS2 (RFC5081). Other application integration strategies are very likely to mirror these constraints. In particular, host-based service naming, mutual authentication and support for channel binding are likely to be important for defense against phishing attacks. The working group will ensure that any solution developed has technical controls for privacy protection. Other than a change to its applicability statement and the development of EAP mechanisms, the working group may not change EAP, RADIUS or Diameter without establishing consensus with the appropriate community within the IETF. The working group will use the following documents as a starting point for its work: - draft-howlett-eap-gss-00, - draft-howlett-radius-saml-attr-00 - draft-hartman-gss-eap-naming-00 Concerns have been raised that additional work is required in keying AAA associations in a federated environment. The working group is chartered to explore these concerns and if needed, specify protocols that use existing AAA key management mechanisms to address these concerns. Coordination with other SDOs ---------------------------- The Working Group will work in conjunction with the IAB to establish appropriate liaison relationships with the OASIS Security Services Technical Committee (SSTC) and take care that any changes or profiling required in SAML can be properly coordinated across the different organizations. In particular coordination is required with respect to the SAML-RADIUS binding. Deliverables ------------ 1. Descriptions of applicable use cases (informational). 2. An architecture that describes how the components of the solution fit together to address the use cases and open issues that will require future changes to the architecture (informational). 3. A standards-track update to the EAP applicability statement in RFC 3748 describing the applicability of EAP to application authentication and placing appropriate requirements on this new EAP use case. 4. A standards-track solution for using EAP methods to provide authentication within the application. 5. A standards-track update to the EMSK root key applicability statement in RFC 5295. 6. A standards-track description of GSS names and name attributes required by the solution. 7. Descriptions of usability and user-interface concerns related to this work (informational). 8. A standards-track protocol for carrying SAML messages in RADIUS and Diameter. Goals and Milestones: Oct 2010 Submit Internet draft describing applicable use cases as initial WG item. Oct 2010 Submit Internet draft describing the architecture as initial WG item. Oct 2010 Submit Internet draft that updates the EAP applicability statement as initial WG item. Oct 2010 Submit Internet draft for using EAP methods to provide authentication within the application as initial WG item. Oct 2010 Submit Internet draft that updates the EMSK root key applicability statement as initial WG item. Oct 2010 Submit Internet draft that describes GSS names and name attributes as initial WG item. Oct 2010 Submit Internet draft for usability and user-interface concerns as initial WG item. Oct 2010 Submit Internet draft for SAML messages in Radius and Diameter as an initial WG item. Dec 2010 Submit Internet draft describing applicable use cases to the IESG for consideration. Dec 2010 Submit Internet draft describing the architecture to the IESG for consideration. May 2011 Submit Internet draft that updates the EAP applicability statement to the IESG for consideration. May 2011 Submit Internet draft for using EAP methods to provide authentication within the application to the IESG for consideration. Aug 2011 Submit Internet draft that updates the EMSK root key applicability statement to the IESG for consideration. Aug 2011 Submit Internet draft that describes GSS names and name attributes to the IESG for consideration. Aug 2011 Submit Internet draft for usability and user-interface concerns to the IESG for consideration. Dec 2011 Submit Internet draft for SAML messages in Radius and Diameter to the IESG for consideration. Internet-Drafts: Posted Revised I-D Title ------ ------- -------------------------------------------- Oct 2010 Feb 2011 A GSS-API Mechanism for the Extensible Authentication Protocol Oct 2010 Mar 2011 A RADIUS Attribute for SAML Messages Mar 2011 Mar 2011 Application Bridging for Federated Access Beyond web (ABFAB) Use Cases Request For Comments: None to date.