1. Authorization…
It’s not just about who you are
David Brossard, @davidjbrossard
Product Manager Axiomatics AB
Member of the OASIS XACML Technical Committee

2. Axiomatics 2
What’s authorization?
“The authorization function determines whether a
particular entity is authorized to perform a given
activity, typically inherited from authentication
when logging on to an application or service.”

3. 3
What happens when authorization isn’t done right?
http://www.hhs.gov/ocr/privacy/hipaa/administrative/breachnotificationrule/breachtool.html
http://www.informationisbeautiful.net/visualizations/worlds-biggest-data-breaches-hacks/
New York City Health & Hospitals
Corporation Releases Electronic
Health Records
1 700 000
Citi Exposes Details of 150,000
Individuals Who Went into
Bankruptcy
150 000
6 000 000 Facebook’s Download Your
Information releases too much
information about your contacts

4. Axiomatics 4
Authorization is that necessary evil developers must do
But I want to do
app development
Daddy…
You will secure your
app first my son…

5. Axiomatics 5
But we, developers, hate spending time on security
80%
20%
Time spent developing an application
Business logic
Security
* And no this isn’t PacMan

6. Axiomatics 6
So how do developers do it today?
{nothing}
{application
frameworks}
{home-
grown}

7. 7
We tend to reinvent the wheel

8. Axiomatics 8
Examples of authorization frameworks (Java & Others)
JAAS
CanCan
Apache Shiro
Spring Security
Rails AuthZ
Microsoft Claims
Slim for PHP

9. In the olden days, authorization was about
Who?

10. Axiomatics 10
So how do you handle additional information?
Context Location Relationship
Classification Parent Delegation Guardian IP
address Device Pattern Behavior Risk
Clearance Employment Citizenship Time
Intellectual PropertyExport Control

11. Authorization should really be about…
When?What? How?Where?Who? Why?
11
Credits: all icons from the Noun Project | Invisible: Andrew Cameron, | Box: Martin Karachorov | Wrench: John O'Shea | Clock: Brandon Hopkins
Attribute-based Access Control
Welcome to…

12. Axiomatics 12
What’s an attribute?
An identifier
e.g. citizenship
A datatype
e.g. string
A category / object it describes
e.g. the user, the resource

13. An introduction to XACML
Axiomatics

14. Axiomatics
Behold XACML!
 eXtensible Access Control Markup Language
 An OASIS standard
 The de facto standard for fine-grained access control
 Current version: 3.0
 XACML defines
 A policy language
 A request / response scheme
 An architecture

15. 15
Three key points of XACML
Policy-based Attribute-based Technology-
neutral
Apply XACML to
Java, .NET, and more
Use policies to describe and
implement complex AuthZ
An attribute consists
of an
identifier, datatype, a
nd value

16. XACML Architecture Flow
16
Decide
Policy Decision Point
Manage
Policy Administration Point
Support
Policy Information Point
Policy Retrieval Point
Enforce
Policy Enforcement Point
Access
Document #123
Access
Document #123
Can Alice access
Document #123?
Yes, Permit
Load XACML
policies
Retrieve user
role, clearance
and document
classification

17. 17
Any-depth Authorization

18. Anywhere Authorization
18

19.  3 structural elements
 PolicySet
 Policy
 Rule
 Root: either of PolicySet or Policy
 PolicySets contain any number of PolicySets & Policies
 Policies contain Rules
 Rules contain an Effect: Permit / Deny
 Combining Algorithms are used to resolve conflicts
between rules
Language Elements of XACML

20. Root Policy
Set
PolicySet
Policy
Rule
Effect=Permit
Rule
Effect = Deny
PolicySet
Policy
Rule
Effect =
Permit
Sample XACML Policy

21. Language Structure: Russian dolls
PolicySet, Policy &
Rule can contain
Targets
Obligations
Advice
Rules can contain
Conditions
Policy Set
Policy
Rule
Effect=Permit
Target
Target
Target
Obligation
Obligation
Obligation
Condition

22. Axiomatics 22
The one question that matters in XACML
Can Manager
Alice approve
Purchase
Order 12367?
Yes, she can!

23. • Subject
User id = Alice
Role = Manager
• Action
Action id = approve
• Resource
Resource type = Purchase Order
PO #= 12367
• Environment
Device Type = Laptop
23
Structure of a XACML Request / Response
XACML Request XACML Response
Can Manager Alice approve
Purchase Order 12367?
Yes, she can
• Result
Decision: Permit
Status: ok
The core XACML specification does not
define any specific transport /
communication protocol:
-Developers can choose their own.
-The SAML profile defines a binding to send
requests/responses over SAML assertions

24. Sample Use Case
Axiomatics

25. Axiomatics
Sample Scenario – a CRM use case
 A customer representative of a large financial
organization needs to access customer data
 The compliance manager, the application owner, and
the chief security officer agree on certain “rules”
No one can access
data outside office
hours
Customer reps can
view accounts in
their region
Our customers can
blacklist some of our
employees
Customer reps
cannot work on
family accounts

26. XACML lets you define and group policies
 Sample policies
 No one can access data outside office hours
 Customer reps can view accounts in their region
 Customer reps cannot work on family accounts
 Our customers can blacklist some of our employees
 Note
 XACML lets you define negative and positive rules
 XACML can use any number of attributes
 XACML can combine policies together and define conflict
resolutions
 Policies are usually generic but can also be user-specific

27. The example reworked
 Overall policy: access customer record
 DENY if time < 9am OR time > 5pm
 DENY if employee.location!=customer.location
 DENY if customer.id belongs to employee.family
 ALLOW access

28. Implement the policies using ALFA
 ALFA plugin for Eclipse
 Add-on to the Eclipse IDE
 Write XACML using a pseudo-code called ALFA – the
Axiomatics Language for Authorization
 Free download from www.axiomatics.com
Hands-on demo

29. XACML for the Java
Developer
Axiomatics

30. 30
Use the same enforcement SDK across all your apps
XACML Enforcement Point SDK

31. Axiomatics
Example: use Java Servlet Filters
 Protect Java web apps
public class ServletPEP implements javax.servlet.Filter{
@Override
public void destroy() {
// TODO Auto-generated method stub
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
}
@Override
public void init(FilterConfig arg0) throws ServletException {
}
}

32. Example: use JAX-WS interceptors
 Protect Java web services
 Can be applied inbound and outbound
 Inspect the payload of the messages
 Also applicable to JAX-RS services
/*
* (non-Javadoc)
*
* @see
javax.xml.ws.handler.Handler#handleMessage(javax.xml.ws.handler.
* MessageContext)
*/
public boolean handleMessage(SOAPMessageContext context) {
}

33. Example: use AOP – annotations
 Example: a Student Management Service
 Create, grade, and delete students
 Apply the @XacmlEnforcementPoint annotation
 Annotate the POJOs with @XacmlAttribute
public interface StudentService {
@XacmlEnforcementPoint
Student createStudent();
}
class Student {
@XacmlAttribute
String name;
@XacmlAttribute
Integer age;
}

34. Other areas
 Spring Security
 JAAS integration
 JSP taglibs
 JMS
 Can you name any?
 Goal: provide a unified, standardized way of applying
fine-grained authorization across multiple applications

35. XACML simplifies authorization management
 The authorization logic is externalized into XACML
policies
 You no longer need to write Java code
 If the authorization logic changes, update the policies
 Strive for configuration-based authorization
 E.g. via interceptors (servlet filters, JAX-WS handlers)
 Configure the handlers using the target framework’s config files
(e.g. web.xml)

36. XACML saves you time
80%
20%
Before
Business
logic
Security
95%
5%
After
Business
logic
Security

37. Beyond Java
 Apply the same architectural approach and XACML
policies to
 .NET
 Perl
 Python
 Ruby
 Business apps
 And more!

38. A few parting words

39. 39
Just a spoonful of XACML makes…
Consolidated
authorization
Enhanced
security
Business
enabler
Compliance
Expose data and APIs
to new customers
Write once,
Enforce everywhere
Consistent
authorization
enforcement
Implement
legal frameworks

40. Axiomatics
Do you want to chip in?
 OASIS XACML TC
https://www.oasis-open.org/committees/xacml/
 Online resources
http://www.xacml.eu

41. Questions?