XACML 2.0 implementation for CEDA (the Centre for Environmental Data Analysis) STFC, Rutherford Appleton Laboratory. This is follow on work from the NERC (Natural Environment Research Council) DataGrid 3 Project.
XACML (eXtensible Access Control Mark-up Language), is an XML based language for expressing access control policies.
See: http://www.oasis-open.org/committees/xacml/
- Fix for test_pdp with SubjectMatch semantics - ALL values must match within a element for a rule match
- Added MANIFEST.in to fix missing policy files in test area
- fixed epydoc mark-up
Major enhancements including additional language features and support for lxml:
- Optional support for lxml as alternative to ElementTree - gives better Xpath support
- Added concatenate functions and custom functions for URL encoding and MD5 hash custom functions.
- Added support for language features:
- for SAML 2.0 profile of XACML v2.0 (http://docs.oasis-open.org/xacml/2.0/access_control-xacml-2.0-saml-profile-spec-os.pdf)
- AttributeSelectors
- PolicySets.
- first-applicable rule combining algorithm
- Incorporated NOT and modified AND functions (from Prashant Kediyal).
- Support for adding custom functions with ndg.xacml.core.functions.FunctionMap.load_custom_function
- Fix for ticket:1130 and related bug
- In ndg.xacml.core.target.Target._matchChild, all SubjectMatches within a Subject must evaluate to true for an overall match for the Subject (and similarly for Resource, Action and Environment).
- In ndg.xacml.core.match.MatchBase, matching of the attribute value for a SubjectMatch with any of the values for the selected attribute of the Subject should result in an overall match (and similarly for Resource, Action and Environment).
Added support for custom DataTypes and functions. e.g.
# Add attribute value type
AttributeValueClassFactory.addClass('<my new type uri',
MyAttributeValueClass)
# ...and new parser for this type
DataTypeReaderClassFactory.addReader('<my new type uri',
ETreeMyDataTypeReaderClass)
# Add new function
functionMap['<my function type uri'] = MyNewFunctionClass
Includes important fixes for equals functions, and improvement to at least one member functions. Unit tests improved with wider coverage of different rule definitions and example request contexts.
Improved and added to support for context handler and Policy Information Point interfaces including the ability for the PDP to call back to a PIP via a Context handler to retrieve additional subject attributes.
Only the parts of the specification immediately required for CEDA have been implemented in this initial release: Policy Decision Point; Deny overrides and Permit overrides rule combining algorithms; AttributeDesignators; various function types: see ndg.xacml.core.functions; and attribute types: see ndg.xacml.core.attribute; incomplete support for s, , . ; includes an ElementTree based parser for Policies. No support for writing out policies or read/write of XML representation of and ;
See ndg.xacml.test for unit tests and examples.
The software follows a modular structure to allow it to be extended easily to include new parsers, functions and attribute types