TeraGrid Plans for Authentication and

Authorization Testbed

Dane Skow, Argonne National LaboratoryComputation Institute Seminar

September 28, 2006

Workshop

• Workshop on TeraGrid Authentication, Authorization, and Account Management - August 30-31, 2006, Argonne National Laboratory– Organizers: Von Welch, Tony Rimovsky, Jim Marsteller,

Carolyn Peters, Dane Skow

• Attendees: 42 persons, representatives from all TeraGrid Resource Provider sites, OSG, Internet2, Globus

• http://www-fp.mcs.anl.gov/tgmeeting/AAA-Agenda.htm

• Whitepaper (Von Welch, Ian Foster, Tom Scavo, Frank Siebenlist,

Charlie Catlett) http//gridshib.globus.org/tg-paper.html

Authentication vs Authorization

•Identifier: A unique name – (username, DN, GUID, SSN, etc.)

•Authentication: Verifying Identity of users – associating them with a Identifier Authorization: Deciding whether or not a request will be granted

– Different authentication methods have different levels of certainty

•Authorization Policy: The set of rules by which an authorization decision is made

•Authentication does not imply Authorization– E.g. just because you trust a CA doesn’t mean all the user with certificates from it are authorized

Issues with Authentication Status Quo

• IDs sometimes contain sensitive information (e.g. SSN)

• ID sources do not typically have direct, ongoing relationship with users

• Many sources of authentication mean confusion, error and insecurity for all parties

• Protection of online secrets is difficult and point of attack

• Scaling beyond ~100 sources of identity call for index and/or hierarchy– 100+ in MacOS X default, etc– Currently 90+ CAs in IGTF PMA set– ~1500 Institutions in EDUCAUSE

Authorization Status Quo

• Currently solely ID based– A user has only one mapping in the system

•no capability for roles•Single group membership

• Need prior knowledge of group membership– Maintenance /synchronization problem

• No differentiation between services for access levels– Allocated users– Authenticated users– TG Community users– Partner/Campus users– Public

• Scaling– Workload scales by ID not by group– Adds new sources of authority to manage

Account Management Status Quo

• Single Account/authorization doesn’t map to rich set of services

• Persistent Execution Environments– Pre-provisioning individual environments (accounts) has large overhead and vulnerabilities

– Shared environments – Environment configuration for groups must be independently duplicated

• Traceable actions– Need to preserve connection from actions (and costs) to individual initiating the action for troubleshooting

Operational Example

• Number and Levels of Credentials– Resource specific (login) credentials

•Direct machine logins•TeraGrid webpages•TeraGrid forum

– Grid service credentials•Users internal TeraGrid X509 credentials (from kx509, MyProxy, etc)•Gateway/broker credentials•User’s external x509 credentials (from DOEGrids, etc)

– Gateway community credentials•Portal login/password•Home institution credentials

– Commercial credentials

• Scale of compromise recovery effort is large– Single general server compromise 1000s of credentials

Authentication Process Today

•User and RP share a secret.– RP authoritative itself

•Maintains contact information– User <-> RP correction relationship– Individual traceability *

•CAs issue identify credentials– RP can validate credentials (trusting CA)– CA maintains contact information (maybe)– Typically not available to RP– CA has loose relation to user– User <-> CA <-> RP correction relationship– Individual traceability *

* Provided there’s no collusion

Future

•User authenticates to local institution/authority,– authority vouches for user (by constructing appropriate attributes in credential)

– RP can validate authority attribute and binding to request (?)

– RP may itself be a local institution– Local institution maintains contact information with user

– Heirarchies allowed (ala bond brokers)– Individual traceability (maybe pseudynmous)

Individual User Environment

ResourceTGCDBuid

uiduid project

(G)Id(G)Id(G)Id

Grant Process

Use cases:Traditional users, Development

O(10)

O(1)O(10)

O(1000)O(1000)

O(1)

Authenticated User Environment

ResourceTGCDB

project

(G)Id(G)Id(G)Id

Grant Process

Use cases:Grid-savvy user communities, Production runs, user managed services

uidO(10) ?

O(10)

O(1)

O(1)

O(10)

O(1)

Gateway

Gateway Environment

ResourceTGCDB

project

Grant Process

Use cases:Large communities of users, novice users, public

uiduid

GId

ComId

O(1) ?

O(10)

O(10)O(1)

O(10)

O(1) ?

O(1)O(100) ?

O(1000)

O(100)O(1000)

O(100)

O(100-106) ?

O(1)

Community Gateway Accounts

•Shift authentication and authorization from RP to the Science Gateway

•Whole community then appears as “one” user to the RP in terms of authorization–One grid-mapfile and /etc/password entry

•or perhaps (a mapped set of) virtual machine images

–Except accounting and troubleshooting. We still need an individual identifier

The Proposal

•Plan for a world where users can be authenticated via their home campus identity management system

•Enable attribute-based authorization of users by RP site– Allow for user authentication with authorization by community

•Prototype system in testbed, with involvement of interested parties to work out issues

•All usage still billed to an allocation– Community or individual

Testbed

Testbed Components

•Enhanced CTSSv3 stack– Existing GT component extensions to enable attribute-based authorization

•Identify testbed resources– UChicago/ANL, NCSA Mercury, ORNL

– Use OSG/TG VOMS test server

•Handful of user communities– Science Gateway, Educational, OSG, others TBD.

•Use of Shibboleth and related software– myVocs, GridShib

– Leverage InQueue/TestShib, UT Fed

Testbed Use Cases

1. Individual New User2. Individual Existing User Access3. Shibboleth authentication to Gateway4. Gateway attribute authorization to RP Use

Case5. OSG/VOMS access6. Educational Access7. Incident Response

Individual New TG User

• Registration process here…– Campus id gets into TGCDB as part of process– Utilize Shibboleth tooling for Registration process

• User authenticate with campus credentials– Gets short-lived X509 credential with DN based on Shibboleth-provided Id

– With campus attributes– No TG attributes (maybe project in future?)

• User access via gsi-ssh, GRAM, gridftp– X509 cred w/attributes presented to RP– DN+attribute registration matched to local UID through gxmap (mod)

• RP does authorization based on DN– Provisioning may use attribute common set (TBD)– TP logs other attributes

Identifying Key Communities

•Large enough to suffer scaling problems– So there’s a payoff for the work

•Feasibly represented by Shibboleth or VOMS in the next 2 years

•Or represented by a persistent attribute authority (e.g. a Gateway)– So that it’s not yet another security system

•Some subset of community represented now– So that there’s someone to work with in evaluating the use cases

Technical and Policy Issues to be Resolved (a subset)

• What identifiers and attributes are needed by TeraGrid from campuses?

• How will other attributes be sourced? E.g. Gateway communities.

• Policy distribution mechanisms– Consistent TG-wide policy vs Site autonomy

• Agreement between TeraGrid and campuses providing attributes

• Identify issues related to forensics/incident response and accounting

• Scaling issues with key services

Issues which will remain challenges

•Numerous, small, dynamic VOs will remain difficult to support– This is key to capturing the ultimate vision of grid as infrastructure

•Policy rules (expression and interpretation) remain terra incognita– There are grammars and engines, but little operating experience

•Scaling growth in number of authorities needs improvement– Lessons to be learned from DNS

Phased Deployment

1. Enable logging of attributes through the system

– Improves traceability and prepares for attribute handling

2. Enable group membership decisions based on attributes

– Provides for community based authorization

3. Enable attribute based authorization/provisioning decisions

– Enables user mapping to different environments– Enables specialized provisioning by attribute

set