eXtensible Access Control Markup Language - XACML
Statement of Purpose/List of Deliverables
The XACML Technical Committee will define a core XML schema for representing authorization and entitlement policies, also called XACML.
The target of a policy (hereafter referred to as "target") can be any object that can be referenced using XML.
Protocols and Bindings
The XACML Technical Committee will identify bindings to existing protocols (e.g., XPath, LDAP), and define new protocols, if necessary, as means of accessing and communicating the policies.
XACML is expected to address fine grained control of authorized activities, the effect of characteristics of the access requestor, the protocol over which the request is made, authorization based on classes of activities, and content introspection (i.e. authorization based on both the requestor and potentially attribute values within the target where the values of the attributes may not be known to the policy writer). XACML is also expected to suggest a policy authorization model to guide implementers of the authorization mechanism.
XACML core schema is extensible for as yet unknown features
The XACML Technical Committee will define interoperability of XACML core schema with other standards. To ensure work is not duplicated and standards adoption is as simple as possible, XACML shall adopt as baseline documents the work products of the Security Services Technical Committee including but not limited to a Domain Model and Glossary. Furthermore, Use Cases and Requirements documents will share content that is common through normative references. The XACML TC shall keep its work consistent with the work of the Security Services TC by requesting enhancements to, modifications of, and cross-references from Security Services TC documents through a formal liaison with the Security Services TC. This liaison will include the regular sharing of deliverables and status reports during teleconferences or at face-to-face meetings.
Successfully Using the XACML Specification:
XACML is an XML schema for representing authorization and entitlement policies. However, it is important to note that a compliant Policy Decision Point (PDP) may choose an entirely different representation for its internal evaluation and decision-making processes. That is, it is entirely permissible for XACML to be regarded simply as a policy interchange format, with any given implementation translating the XACML policy to its own local/native/proprietary/alternate policy language sometime prior to evaluation.
A set of test cases (each test case consisting of a specific XACML policy instance, along with all relevant inputs to the policy decision and the corresponding PDP output decision) will be devised and included on the XACML Web site. These test cases are provided to assist implementers in creating implementations that are conformant with the XACML specification.