gridshib: campus/grid rbac integration penn state grid computing workshop august 5th, 2005

GridShib:Campus/Grid RBAC

Integration

Penn State Grid Computing WorkshopAugust 5th, 2005

Von Welch

[email protected]

August 5th, 2005 2PSU Grid Computing Workshop

Outline• Overview of Shibboleth and Globus

• Our Motivation and Use Cases

• Integration Approach

• Status


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

http://shibboleth.internet2.edu/


Acknowledgements• 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

• 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


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


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


Shibboleth (Simplified)

AA

SSO

ShibbolethIdP

Handle

Attributes

SAML

AR

ACS

ShibbolethSP

Handle

LDAP(e.g.)


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


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


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


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


GridShib (Simplified)

A

SSO

Shibboleth

DN

Attributes

DN

DN

SAML

SSL/TLS, WS-Security


Integration Areas• Assertion Transmission

• Attribute Authority Discovery

• Distribute Attribute Administration

• User Registration

• Pseudonymous Interaction

• Authorization


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


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


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/


LDAP

Getting Attributes into a Site’s Attribute Authority

uid: jdoeeduPersonAffiliation: …isMemberOf: …eduPersonEntitlement: …

SIS

HR

On-site Authorities

Loaders PersonRegistry

GroupRegistry

GrouperUI

PrivilegeRegistry

Off-site Authorities

SignetUI

Attribute Authority

Core Business Systems

Shib/GridShib

using Shibboleth


User Registration• How does the mapping from the User’s X509

DN to local Campus identity get made in NameMapper configuration?

• In initial version, this will be manual process• Yes, far from ideal• We envision

– Something akin to a registration service that authenticates user’s X509 and local credentials and puts mapping in automatically

– Or a portal that hides all the X509 from the user and also handles this mapping

• E.g. PURSE, GAMA


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


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…)


GridShib Status• Testing initial version internal to project

• Will be a drop-in addition to GT 4.0 and Shibboleth 1.3

• Current adapting to last minute Shibboleth 1.3 changes and doing internal testing

• Plan on beta release in 2-3 weeks

• Looking for interested beta testers


Questions?• Project website:

– http://grid.ncsa.uiuc.edu/GridShib/

• My email:– [email protected]

http://grid.ncsa.uiuc.edu/GridShib/





gridshib: campus/grid rbac integration penn state grid computing workshop august 5th, 2005

Documents