Shibboleth

Authenticate Locally, Act GloballyA Penn State Case Study

Agenda• Shibboleth - Background and Status• Technical Review -- how does it work?• Shibboleth - Why?• Penn State Background• “Shibbified” Penn State Applications• Integrating Shibboleth with the PSU infrastructure• Future

What is Shibboleth?• An initiative to develop an architecture and policy framework supporting the sharing – between domains -- of secured web resources and services

• Built on a “Federated” Model• A project delivering an open source implementation of the architecture and framework

Deliverables:–Software for Origins (campuses)–Software for targets (vendors)–Operational Federations (scalable trust)

Shibboleth Goals• Use federated administration as the lever; have the

enterprise broker most services (authentication, authorization, resource discovery, etc.) in inter-realm interactions

• Provide security while not degrading privacy.–Attribute-based Access Control

• Foster inter-realm trust fabrics: federations and virtual organizations

• Leverage campus expertise and build rough consensus• Influence the marketplace; develop where necessary• Support for heterogeneity and open standards

Attribute-based Authorization• Identity-based approach

–The identity of a prospective user is passed to the controlled resource and is used to determine (perhaps with requests for additional attributes about the user) whether to permit access.

–This approach requires the user to trust the target to protect privacy.

•Attribute-based approach–Attributes are exchanged about a prospective user until the

controlled resource has sufficient information to make a decision. –This approach does not degrade privacy.

Stage 1 - Addressing Four Scenario’s•Member of campus community accessing licensed resource

–Anonymity required•Member of a course accessing remotely controlled resource

–Anonymity required•Member of a workgroup accessing controlled resources

–Controlled by unique identifiers (e.g. name) •Intra-university information access

–Controlled by a variety of identifiers•Taken individually, each of these situations can be solved in a variety of straightforward ways. •Taken together, they present the challenge of meeting the user's reasonable expectations for protection of their personal privacy.

So… What is Shibboleth?•A Web Single-Signon System (SSO)?

•An Access Control Mechanism for Attributes?

•A Standard Interface and Vocabulary for Attributes?

•A Standard for Adding AuthN and AuthZ to Applications?

Shibboleth Status• Software Availability

– Version 1.1 available August, 2003– Version 1.2 available March, 2004– Version 1.3 available Summer, 2003– Target implementation - works with Apache and IIS targets

• Campus Adoption accelerating…• Working with second round of information

vendors• Java target implementation underway• Work underway on some of the essential

management tools such as attribute release managers, target resource management, etc.

Shibboleth Status

• Likely to coexist well with Liberty Alliance and may work within the WS framework from Microsoft.

• Growing development interest in several countries, providing resource manager tools, digital rights management, listprocs, etc.

• Used by several federations today – NSDL, InQueue, SWITCH and several more soon (JISC, Australia, etc.)

High Level Architecture• Federations provide common Policy and Trust• Destination and origin site collaborate to provide a

privacy-preserving “context” for Shibboleth users• Origin site authenticates user, asserts Attributes• Destination site requests attributes about user directly

from origin site• Destination site makes an Access Control Decision• Users (and origin organizations) can control what

attributes are released

Technical Components• Origin Site – Required Enterprise Infrastructure

–Authentication–Attribute Repository

• Origin Site – Shib Components–Handle Server –Attribute Authority–Attribute Release Policy

• Target Site - Required Enterprise Infrastructure–Web Server (Apache or IIS)

• Target Site – Shib Components–SHIRE–SHAR–WAYF–Resource Manager

Shibboleth AA ProcessR

esource

WAYF

Users Home Org Resource Owner1

SHIRE

I don’t know you.Not even which home

org you are from.I redirect your request

to the WAYF32

Please tell me where are you from?

HS

5

6

I don’t know you.Please authenticateUsing WEBLOGIN

7

User DB

Credentials

OK, I know you now.I redirect your requestto the target, together

with a handle

4

OK, I redirect yourrequest now to

the Handle Service of your home org.

SHAR

Handle

Handle8

I don’t know theattributes of this user.Let’s ask the Attribute

Authority

Handle9AA

Let’s pass over the attributes the userhas allowed me to

release

Attributes 10

Resource

Manager

Attributes

OK, based on theattributes, I grant

access to the resource

Shibboleth Architecture (still photo, no moving parts)

Attribute Authority --Management of Attribute Release Policies

• The AA provides ARP management tools/interfaces.

– Different ARPs for different targets– Each ARP Specifies which attributes and which values to

release– Institutional ARPs (default)

• administrative default policies and default attributes• Site can force include and exclude

– User ARPs managed via “MyAA” web interface– Release set determined by “combining” Default and User ARP

for the specified resource

Typical Attributes in the Higher Ed Community

Affiliation “active member of community”

member@washington.edu

EPPN Identity gettes@duke.edu

Entitlement An agreed upon opaque URI

urn:mace:vendor:contract1234

OrgUnit Department Economics Department

EnrolledCourse Opaque course identifier

urn:mace:osu.edu:Physics201

Trust, and Identifying Speakers• Federations distribute files defining the trust fabric• Individual sites can create bilateral trust• When a target receives a request to create a session, the

Authn Assertion must be signed by the origin (PKI validation), and the origin must be a member of a common Federation.

• When an Origin receives a request for attributes, it must be transported across SSL.

• The name of the Requestor (from the certificate) and the name of the user (mapped from the Handle) are used to locate the appropriate ARP.

Target – Managing Attribute Acceptance

•Rules that define who can assert what…..•MIT can assert student@mit.edu•Chicago can assert staff@argonne.gov•Brown CANNOT assert student@mit.edu

•Important for entitlement values

Managing Authorization•Federations will NOT require members to do business with each other

•Target manages Access Control Policy specifying

–what attributes must be supplied –and from which origins–in order to gain access to specific resources

•Rules are attribute based

What are federations?• Associations of enterprises that come together to exchange

information about their users and resources in order to enable collaborations and transactions

• Built on the premise of –Initially “Authenticate locally, act globally”–Now, “Enroll and authenticate and attribute locally, act federally.”

• Federation provides only modest operational support and consistency in how members communicate with each other

• Enterprises (and users) retain control over what attributes are released to a resource; the resources retain control (though they may delegate) over the authorization decision.

• Over time, this will all change…

Shibboleth -- Next Steps•Full implementation of Trust Fabric

–Supporting Multi-federation origins and targets

•Support for Dynamic Content (Library-style Implementation in addition to web server plugins)

•Sysadmin GUIs for managing origin and target policy

•Grid, Virtual Organizations•? Saml V2.0, Liberty, WS-Fed•NSF grant to Shibboleth-enable open source collaboration tools

•LionShare - Federated P2P

Penn State Background• 24 campus locations• Distributed Computing Environment (DCE)

– 184,556 Principals– User managed groups

• MIT Kerberos V– Fully populated, production 4/1

• IBM’s LDAP 5.1– eduPerson

Why Shibboleth?

• True collaborative effort• Open Source/Open Standards• Solves today’s problems• Leverages existing infrastructure• Authentication agnostic• Emphasis on privacy (FERPA)• Position to co-exist/support other federated

identity solutions on the horizon• We like Ken….

Pilot with WebAssign

• Summer 2002– ~ 20 students, 2 weeks, 1 course

• Fall 2002– ~200 students– 3 courses

• Spring 2003– ~1800 students– Successful login: 63,026 – All courses at UP location can use Shibboleth

• Now in “Limited Production”

WebAssignHistorically, first two weeks - 25 to 30 questions/day Almost all are login problems

WebAssign questions

0

5

10

15

20

25

30

35

Date

Que

stio

nsThis semester -

Numbers of queries in the “Shibbilized” courses …..~1 or 2/day

A reduction of ~85%

Numbers of queries in the normal courses remain at ~15/day

Napster

• Requirement to “Authenticate locally, Act Globally”. Sound Familiar….

• Created 2 teams of PSU/Napster staff– MDS

• Caching Server, Networking, etc– Authentication/Registrationprocess

–Shibboleth

Penn State Origin Site• 7 Origin servers

– 2 WebAssign– 5 Napster

• Load balance using SLB• Software

– Shibboleth 1.1• Hardware

– IBM Blade HS20 proc 2.4GHz mem 2.5Gig

Penn State Origin Site

• Currently member of InQueue• Will join InCommon ASAP• Not using WAYF• Used to access external web resources

Future

• Shibboleth Meteor Gateway• AT&T Wireless• Use Shibboleth to access PHEAA from student

web applications• Use Shibboleth Phase II for non Web

applications such as LionShare (P2P)• Continue to pilot with library vendors

– Currently working with JSTOR, OCLC– eZProxy

• Incorporate University of Michigan’s Cosign (WebISO) with our origin site

THE END• Acknowledgements:

• Design Team: David Wasley (U of C); RL ‘Bob’ Morgan (U of Washington); Keith Hazelton (U of Wisconsin

(Madison));Marlena Erdos (IBM/Tivoli); Steven Carmody (Brown); Scott Cantor (Ohio State)

• Important Contributions from: Ken Klingenstein (I2); Michael Gettes (Duke), Scott Fullerton (Madison)

• Coding: Derek Atkins (MIT), Parviz Dousti (CMU), Scott Cantor (OSU), Walter Hoehn (Columbia)