FW: [xacml] Re: [xacml-comment] D024

[Daniel Engovatov <dengovatov@crosslogix.com>]

<?xml version="1.0" encoding="UTF-8"?>
<Policy/>

against

<?xml version="1.0" encoding="UTF-8"?>
<RequestContext/>

Both structures are valid XML, aren't they? What would a compliant valid
PDP evaluate this scenario to?

--------------

They are not, not according to this schema: 

	<xs:element name="Policy" type="xacml:PolicyType"/>
	<xs:complexType name="PolicyType">
		<xs:sequence>
			<xs:element ref="xacml:Description" minOccurs="0"/>
			<xs:element ref="xacml:PolicyDefaults"
minOccurs="0"/>
			<xs:element ref="xacml:Target"/>
			<xs:element ref="xacml:Rule" minOccurs="0"
maxOccurs="unbounded"/>
			<xs:element ref="xacml:Obligations" minOccurs="0"/>
		</xs:sequence>
		<xs:attribute name="PolicyId" type="xs:anyURI"
use="required"/>
		<xs:attribute name="RuleCombiningAlgId" type="xs:anyURI"
use="required"/>
	</xs:complexType>


In any case it is not the issue of the document validity - but the issue
that the policy exists (and can be "compiled" and accepted independent of
the data context, in the general case.