This article addresses the following authorization requirements.
1. The operation getCustomers
in the service "http://localhost:8280/services/Customers" should only be accessed by users belonging to the admin_customers
group.
2. The operation getEmployees
in the service "http://localhost:8280/services/Customers" should only be accessed by users belonging to the admin_emps
group.
3. Requests to any other service or operation should fail.
<?xml version="1.0" encoding="UTF-8"?> <Policy PolicyId="urn:sample:xacml:2.0:samplepolicy" RuleCombiningAlgId="urn:oasis:names:tc:xacml:1.0:rule-combining-algorithm:first-applicable" xmlns="urn:oasis:names:tc:xacml:2.0:policy:schema:os"> <Description>Sample XACML Authorization Policy</Description> <Target> <Subjects> <AnySubject/> </Subjects> <Actions> <AnyAction/> </Actions> <Resources> <AnyResource/> </Resources> </Target> <Rule Effect="Permit" RuleId="primary-group-customer-rule"> <Target> <Subjects> <AnySubject/> </Subjects> <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/Customers/getCustomers</AttributeValue> <ResourceAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" DataType="http://www.w3.org/2001/XMLSchema#string"/> </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"/> </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_customers</AttributeValue> </Apply> <SubjectAttributeDesignator AttributeId="group" DataType="http://www.w3.org/2001/XMLSchema#string"/> </Apply> </Condition> </Rule> <Rule Effect="Permit" RuleId="primary-group-emps-rule"> <Target> <Subjects> <AnySubject/> </Subjects> <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/Customers/getEmployees</AttributeValue> <ResourceAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" DataType="http://www.w3.org/2001/XMLSchema#string"/> </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"/> </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_emps</AttributeValue> </Apply> <SubjectAttributeDesignator AttributeId="group" DataType="http://www.w3.org/2001/XMLSchema#string"/> </Apply> </Condition> </Rule> <Rule Effect="Deny" RuleId="deny-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/Customers/getCustomers
- User - "admin" belongs only to the "admin_customers" group
- Result - Permit
<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_customers</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/Customers/getCustomers</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/Customers/getCustomers
- User - "admin" belongs only to the "admin_emps" group
- Result - Deny
<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_emps</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/Customers/getCustomers</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>