AHM 2006 September 2006 DyVOSE Project: Experiences in Applying Advanced Authorisation Infrastructures John Watt ( [email protected] )[email protected].

AHM 2006 September 2006

DyVOSE Project: Experiences in Applying Advanced

Authorisation Infrastructures

John Watt ( [email protected] )Richard Sinnott ( [email protected] )

University of Glasgow, Scotland, UK


“Investigating the establishment of scalable Virtual Organisations in an e-Science education domain.”

• 2 year JISC-funded project (May ’04 – July ’06)• In partnership with University of Kent (and EDINA)

Dynamic Virtual Organisations ine-Science Education

http://www.nesc.ac.uk/hub/projects/dyvose


Project Goals (Glasgow)

Creation of a permanent Grid Computing Module (GC5) as an option within the Advanced MSc. postgraduate course in Glasgow’s Computing Science departmentProvide a lasting lab infrastructure to support practical Grid Computing lab sessionsInvestigate technologies that enable Grid Services to be protected with advanced authorisation infrastructures which the students can deploy as part of an assignment


Course Details

Single term course of 20 lectures and 10 tutorials (Jan-Mar)

1st year (’04-’05) – 19 students2nd year (’05-’06) – 16 students

Three short essay/programming assessmentsFinal Exam in June (answer 3 questions of 5)Month-long Programming Assignment

This assignment forms the core of the DyVOSE authorisation investigations


Assignment

In both years the assignment took the following form:

Students are split into two teamsWrite a Grid Service (and a client) in GT3.3 to perform some taskWrite a scheduler that will split a large job into many sub-jobs and submit to the local Condor poolProtect the Grid Service so that some functions are only available to students who are in the same team

For both years, students used PERMIS to protect their Grid Services…


Assignment

Year 1Investigate STATIC privilege management

Roles are issued by a local Source of Authority (SoA) stored in a local LDAP for access to a local service only

Year 2Investigate DYNAMIC privilege management

Roles are issued by a local SoA stored in a local LDAP for accessing local AND REMOTE services

But roles required for access to the REMOTE service are not recognised within the local infrastructure

REMOTE SoA DELEGATES the right to assign these REMOTE roles to the LOCAL SoA (they form a VO!)

Will prove that this can be done SECURELY and EASILY (from a user perspective) with PERMIS…


Generic Java API for Role Based Access Control (RBAC)Provides method-level protection to applications and Web ServicesProtects Grid Services through GGF-standardised SAML Authz APIRoles are issue in the form of X509 Attribute Certificates (ACs)

http://sec.cs.kent.ac.uk/permishttp://www.permis.org


Generic Authorisation

A generic framework for authorisation is defined in X.812 ISO 10181-3 Acc. Ctrl. Framework


PERMIS with GGF Authz API

•PERMIS deployed in Grid Service container•WSDD file contains policy location, LDAP server details and trust info•GSI provides user DN, PERMIS retrieves ACs


PERMIS Components

XML PolicyRoles

and heirarchy

TargetsActionsSOAsDN ScopeAttribute Storelist

LDAPs

Policy Editor toolsyntax checks


PERMIS Components

Privilege Allocator or Attribute Certificate Manager (ACM)Creates and signs X509 Attribute Certificates (ACs) and loads into LDAP

ACs contain digitally signed attributes (roles)PERMIS API verifies PKI chain of trust (if more than unity length) on invocation

Fully supports a static PMIOne SoA, home roles only…


Year 1 Assignment

“Write a Grid service (and client) to parse the Complete Works of Shakespeare and offer a “Search” service to everyone, but a “Sort” service only to members of the same team. Split the job into sub-jobs and submit to the Condor pool.”

Support (as Sys Admins) Create PKI (CA) and p12 certificates for Globus Write a local XML policy to enforce the rules Create LDAP entries and use the ACM to issue ACs to the students

which contain their role

Students were given LDAP and PKI info to amend their PERMIS service

A tough assignment for four weeks. We got 2 completions and about 5 or 6 who were about 90% there.

We have since Shibboleth-enabled this service, check URL at end…


Year 2 Assignment

“Write a Grid Service and client which runs BLAST on a set of data extracted from a remote database and schedule into sub-jobs for submission to the Condor pool”

Student experience much the same as before implementation-wise (deploy PERMIS in container – point to our PMI details)

But the Support part requires a more sophisticated AC allocator application to handle external as well as local roles (among other properties)

Enter the Delegation Issuing Service (DIS)…– (and a slightly modified PERMIS too)


Delegation Issuing Service

No user key pair required to issue ACs‘dis’ user signs all ACs on behalf of the delegator

If a rogue employee is kicked out, any certificates they issued to trustworthy employees are still valid

– Not the case with AC chains

DIS checks the local policy before signingOnly policy-valid ACs can ever be issued

With previous PERMIS tools it is possible to issue ANY AC with ANY role

Deployed as a web service utilising SOAPCan be used anywhere by valid users


Delegation Issuing Service

Extensions to the PERMIS API allow forCross-certification

Allow ACs signed by a remote CA to be recognised– Currently done through an SoA policy extension

Role-mapping Recognise the meaning of an external role

– Currently done by equating the names of the roles in the local policies

» Future tools will do this equality on the fly without having to alter local core policy

The above implement the necessary features to allow Glasgow to issue Edinburgh roles within their PMI and in accordance with both sites policies


DIS Implementation

Web ServiceAXIS, Apache, TomcatNot too tricky

An afternoon Docs fine for this part

Underlying PKIOpenSSLQuite complex

Had to be quite careful with compatibility of VO PKIs

Have written extension to manual detailing the steps required in full


Dynamic PMI Use Case

Student AssignmentStudent were split into two teams

They were issued with Attribute Certificates which assigned them with one of two roles (GlaTeamN and GlaTeamP)

Students implemented a BLAST Grid Service which queried an external database (hosted in Edinburgh) for gene data

Database was PERMIS protected so only members of the correct team got the right data (based on EdTeam roles)

Students PERMIS protected their service so only members of their own team could invoke the service



PERMIS Policy Details

BLAST DATA Service (Edinburgh) Send Nucleotide Data if User presents PERMIS Role

“EdTeamN” Send Protein Data if User presents PERMIS Role “EdTeamP”

BLAST Service (Glasgow) Invoke BLASTN service if User presents PERMIS Role

“GlaTeamN” Invoke BLASTP service if User presents PERMIS Role

“GlaTeamP”



Dynamic DelegationEdinburgh issues a Delegation Statement to the Glasgow SoA that allows them to assign the EDINBURGH PERMIS role ‘EdTeamN/P’

Done through Glasgow policy extension (RoleMapping)

Glasgow SoA delegates the responsibility to issue this role to user ‘ext’

Issues ‘ext’ an Attribute Certificate containing the Edinburgh roles with the delegation flag set

User ‘ext’ assigns the Edinburgh roles to Glasgow students By issuing the Glasgow students Attribute Certificates This user can be in the Glasgow infrastructure or can be the Edinburgh SoA (by

logging into the Glasgow DIS) – both models can be supported (the former being the more direct)

Edinburgh Data Service searches both LDAP directories Service finds User entries in Glasgow LDAP that contain the correct Edinburgh role

– ACCESS GRANTED


Dynamic PMI Use CaseEdinburgh Glasgow

GT3.3 Container GT3.3 Container

BLASTDATA

BLASTSERVICE

PERMIS Service

PERMIS Service

LDAPLDAP

Student

BLASTClient

PPPPCONDOR

“You mayassign

EdinburghRoles”


In Practise


Summary

PERMIS simple to deploy for usersFor sys admins, deployment is tricky, but use is easy

Dynamic Delegation of Authority can be secure and workable

Future tools (next year?) will optimise this processUser need not know of certificates!

Happier usersDyVOSE legacy

Third year of Grid module starting in Jan ’07Permanent Grid Computing Laboratory in NeSC GlasgowA set of tools which we are able to apply to many of our security projects now and in the future

Fancy doing the course next year?http://www.dcs.gla.ac.uk/courses/MSc_ACS/

AHM 2006 September 2006 DyVOSE Project: Experiences in Applying Advanced Authorisation Infrastructures John Watt ( [email protected] )[email protected].

Documents

permis slide

permis service

local service

assignment slide

acs slide

local roles

grid services slide

local ldap