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Attributes, Anonymity, and Access: Shibboleth and Globus Integration to Facilitate Grid Collaboration 4th Annual PKI R&D Workshop. Tom Barton, Kate Keahey, Frank Siebenlist, Von Welch. Outline. Overview of Shibboleth and Globus Our Motivation and Use Cases Integration Approach. Shibboleth.
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Attributes, Anonymity, and Access: Shibboleth and Globus Integration to Facilitate Grid Collaboration4th Annual PKI R&D Workshop Tom Barton, Kate Keahey, Frank Siebenlist, Von Welch
Outline • Overview of Shibboleth and Globus • Our Motivation and Use Cases • Integration Approach 4th Annual PKI R&D Workshop
Shibboleth • http://shibboleth.internet2.edu/ • Internet2 project • Allows for inter-institutional sharing of web resources (via browsers) • Provides attributes for authorization between institutions • Allows for pseudonymity via temporary, meaningless identifiers called ‘Handles’ • Standards-based (SAML) • Being extended to non-web resources 4th Annual PKI R&D Workshop
Shibboleth • Identity Provider composed of single sign-on (SSO) and attribute authority (AA) services • SSO: authenticates user locally and issues authentication assertion with Handle • Assertion is short-lived bearer assertion • Handle is also short-lived and non-identifying • Handle is registered with AA • Attribute Authority responds to queries regarding handle 4th Annual PKI R&D Workshop
Shibboleth • Service Provider composed of Assertion Consumer and Attribute Requestor • Assertion Consumer parses authentication assertion • Attribute Requestor: request attributes from AA • Attributes used for authorization • Where Are You From (WAYF) service determines user’s Identity Provider 4th Annual PKI R&D Workshop
Globus Toolkit • http://www.globus.org • Toolkit for Grid computing • Job submission, data movement, data management, resource management • Based on Web Services and WSRF • Security based on X.509 identity- and proxy-certificates • Maybe from conventional or on-line CAs • Some initial attribute-based authorization 4th Annual PKI R&D Workshop
Motivation • Many Grid VOs are focused on science or business other than IT support • Don’t have expertise or resources to run security services • Allow for leveraging of Shibboleth code and deployments run by campuses 4th Annual PKI R&D Workshop
Use Cases • Project leveraging campus attributes • Simplest case • Project-operated Shib service • Project operates own service, conceptually easy, but not ideal • Campus-operated, project-administered Shib • Ideal mix, but need mechanisms for provisioning of attribute administration 4th Annual PKI R&D Workshop
Integration Approach • Conceptually, replace Shibboleth’s handle-based authentication with X509 • Provides stronger security for non-web browser apps • Works with existing PKI install base • To allow leveraging of Shibboleth install base, require as few changes to Shibboleth AA as possible 4th Annual PKI R&D Workshop
Integration Areas • Assertion Transmission • Attribute Authority Discovery • Distribute Attribute Administration • Pseudonymous Interaction • Authorization 4th Annual PKI R&D Workshop
Assertion Transmission • How to get SAML assertions from AA into Globus? • Initially: Pull mode with Globus acting as a Shibboleth Attribute Requestor • Will explore Pull modes to help with privacy and role combination • Implement Grid Name Mapper to map X509 DNs to local identities used to obtain attributes 4th Annual PKI R&D Workshop
Attribute Authority Discovery • No interactive WAYF service in the Grid • Place identifier of Identity Provider in cert • Either in long-term EEC or short-term Proxy Cert • Will explore pushing attributes • Avoids the problem • Might also address combined attributes from multiple AAs 4th Annual PKI R&D Workshop
Distributed Attribute Administration • Campus is ideal for running services, but may not know all attributes of users • How does a campus issue attributes for which it is not authoritative? • E.g. IEEE Membership of staff • In Grid case, Project Membership • This may be the largest hurdle due to social, political and/or legal issues • Need accepted cookbook for process • Plan on exploring signet • http://middleware.internet2.edu/signet/ 4th Annual PKI R&D Workshop
Pseudonymous Interaction • How to maintain Shibboleth pseudonymous functionality with X509? • Will develop online CA that issues certificates with non-identifying DNs • Register with AA just as SSO • Basically holder-of-key assertions 4th Annual PKI R&D Workshop
Authorization • Develop authorization framework in Globus Toolkit • Pluggable modules for processing authentication, gathering and processing attributes and rendering decisions • XACML used for expressing gathered identity, attribute and policy information • Convert Attributes into common format for policy evaluation • Allows for common evaluation of attributes expressed in SAML and X509 (and others…) 4th Annual PKI R&D Workshop
Status • Working on X509 profiles in OASIS • Initial pieces tested • Developing initial pull-mode prototype for initial evaluation 4th Annual PKI R&D Workshop
Acknowledgements and Details • NSF NMI project to allow the use of Shibboleth-issued attributes for authorization in NMI Grids built on the Globus Toolkit • Funded under NSF award SCI-0438424 • Goal: GT 4.2 & Shibboleth 1.3 • GridShib team: NCSA, U. Chicago, ANL • Tom Barton, David Champion, Tim Freemon, Kate Keahey, Tom Scavo, Frank Siebenlist, Von Welch • Working in collaboration with Steven Carmody, Scott Cantor, Bob Morgan and the rest of the Internet2 Shibboleth Design team 4th Annual PKI R&D Workshop
Questions? • Project website: • http://grid.ncsa.uiuc.edu/GridShib/ 4th Annual PKI R&D Workshop