Page Comparison

Here is an example of an XACML policy which addresses the following requirement: a given resource can be accessed only by a user belonging to a particular role, and all requests to access any other resource should fail.

Code Block
<Policy xmlns="urn:oasis:names:tc:xacml:2.0:policy:schema:os" PolicyId="urn:sample:xacml:2.0:samplepolicy" RuleCombiningAlgId="urn:oasis:names:tc:xacml:1.0:rule-combining-algorithm:first-applicable">

...


   <Description>Sample XACML Authorization Policy</Description>

...


   <Target></Target>

...


   <Rule Effect="Permit" RuleId="primary-group-rule">

...


      <Target>
         <Resources>
            <Resource>
               <ResourceMatch MatchId="urn:oasis:names:tc:xacml:1.0:function:string-regexp-match">

...


                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string"

...

>http://localhost:8280/services/echo/</AttributeValue>

...


                  <ResourceAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" DataType="http://www.w3.org/2001/XMLSchema#string"></ResourceAttributeDesignator>

...


               </ResourceMatch>

...


            </Resource>

...


         </Resources>

...


         <Actions>
            <Action>
               <ActionMatch MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">

...


                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>

...


                  <ActionAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id" DataType="http://www.w3.org/2001/XMLSchema#string"></ActionAttributeDesignator>

...


               </ActionMatch>

...


            </Action>

...


         </Actions>

...


      </Target>

...


      <Condition>
         <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-subset">

...


            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-bag">

...


               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin</AttributeValue>

...


            </Apply>

...


            <SubjectAttributeDesignator AttributeId="group" DataType="http://www.w3.org/2001/XMLSchema#string"></SubjectAttributeDesignator>

...


         </Apply>

...


      </Condition>

...


   </Rule>

...


   <Rule Effect="Deny" RuleId="deny-rule"></Rule>
</Policy>

The following are a few valid requests which will result in "Permit/Not Applicable/Deny" once evaluated against the above policy.

The first XACML request

Resource - http://localhost:8280/services/echo/

...

User - "admin" belongs only to the "admin" group
Result - Permit

Code Block

<Request xmlns="urn:oasis:names:tc:xacml:2.0:context:schema:os"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <Subject>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
      <Attribute AttributeId="group"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
     </Subject>
     <Resource>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>http://localhost:8280/services/echo/</AttributeValue>
      </Attribute>
     </Resource>
     <Action>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>read</AttributeValue>
      </Attribute>
     </Action>
     <Environment />
    </Request>

The Second XACML request

Resource - http://localhost:8280/services/echo/
User - "admin" belongs to the "admin" group and the "business" group
Result - Permit

Code Block

<Request xmlns="urn:oasis:names:tc:xacml:2.0:context:schema:os"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <Subject>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
      <Attribute AttributeId="group"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
      <Attribute AttributeId="group"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>business</AttributeValue>
      </Attribute>
     </Subject>
     <Resource>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>http://localhost:8280/services/echo/</AttributeValue>
      </Attribute>
     </Resource>
     <Action>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>read</AttributeValue>
      </Attribute>
     </Action>
     <Environment />
    </Request>

The third XACML request

Resource - http://localhost:8280/services/test/
User - "admin" belongs to the "admin" group
Result - Deny

Code Block

<Request xmlns="urn:oasis:names:tc:xacml:2.0:context:schema:os"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <Subject>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
      <Attribute AttributeId="group"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
     </Subject>
     <Resource>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>http://localhost:8280/services/test/</AttributeValue>
      </Attribute>
     </Resource>
     <Action>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>read</AttributeValue>
      </Attribute>
     </Action>
     <Environment />
    </Request>

The forth XACML request

Resource - http://localhost:8280/services/echo/
User - "admin" belongs to the "business" group
Result - Deny

Code Block

<Request xmlns="urn:oasis:names:tc:xacml:2.0:context:schema:os"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <Subject>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>admin</AttributeValue>
      </Attribute>
      <Attribute AttributeId="group"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>business</AttributeValue>
      </Attribute>
     </Subject>
     <Resource>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>http://localhost:8280/services/echo/</AttributeValue>
      </Attribute>
     </Resource>
     <Action>
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
       DataType="http://www.w3.org/2001/XMLSchema#string">
       <AttributeValue>read</AttributeValue>
      </Attribute>
     </Action>
     <Environment />
    </Request>

Excerpt

hidden	true

Instructions on how to write XACML policies in WSO2 Identity Server. Part 2.

Versions Compared

Old Version 2

New Version Current

Key

The first XACML request

The Second XACML request

The third XACML request

The forth XACML request