Writing XACML 3.0 policies, Diverse Rules Per Operation - 2

This is a continuation from my previous post 'Working with XACML 3.0 policies for fine-grained authorization -1'. Here I will share a sample XACML 3 policy which defines two distinct rules to act over two distinct resources, followed by few sample requests to understand it's behaviour.

Let's imagine a requirement like as follows.
  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.
I have wrote following policy to satisfy this. It's bit longer than the previous policy, but same pattern applies.

<Policy xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17"  PolicyId="sample" RuleCombiningAlgId="urn:oasis:names:tc:xacml:1.0:rule-combining-algorithm:first-applicable" Version="1.0">
   <Description>sample policy</Description>
   <Target></Target>
   <Rule Effect="Permit" RuleId="primary-group-customer-rule">
      <Target>
         <AnyOf>
            <AllOf>
               <Match 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>
                  <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
               </Match>
               <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
                  <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id" Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
               </Match>
            </AllOf>
         </AnyOf>
      </Target>
      <Condition>
         <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
               <AttributeDesignator AttributeId="group" Category="urn:oasis:names:tc:xacml:3.0:example-group" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
            </Apply>
            <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin_customers</AttributeValue>
         </Apply>
      </Condition>
   </Rule>
   <Rule Effect="Permit" RuleId="primary-group-emps-rule">
      <Target>
         <AnyOf>
            <AllOf>
               <Match 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/getEmployee</AttributeValue>
                  <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
               </Match>
               <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
                  <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id" Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
               </Match>
            </AllOf>
         </AnyOf>
      </Target>
      <Condition>
         <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
               <AttributeDesignator AttributeId="group" Category="urn:oasis:names:tc:xacml:3.0:example-group" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
            </Apply>
            <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin_emps</AttributeValue>
         </Apply>
      </Condition>
   </Rule>
   <Rule Effect="Deny" RuleId="deny-rule"></Rule>
</Policy>


As we can notice this has 3 'Rule' elements where two of them define what needs to be permitted and the other to deny all other requests, satisfying each requirement we defined in the beginning in the order. Let's check this with some requests.

  • Admin of admin_customers group tries to access operation 'http://localhost:8280/services/Customers/getCustomers'. Response: Permit

<Request xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17" CombinedDecision="false" ReturnPolicyIdList="false">
<Attributes Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:3.0:example-group">
    <Attribute AttributeId="group" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin_customers</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">http://localhost:8280/services/Customers/getCustomers</AttributeValue>
    </Attribute>
</Attributes>
</Request> 

  • Admin of admin_emps group tries to access operation 'http://localhost:8280/services/Customers/getCustomers'. Response:Deny
<Request xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17" CombinedDecision="false" ReturnPolicyIdList="false">
<Attributes Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:3.0:example-group">
    <Attribute AttributeId="group" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">admin_emps</AttributeValue>
    </Attribute>
</Attributes>
<Attributes Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource">
    <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" IncludeInResult="false">
        <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">http://localhost:8280/services/Customers/getCustomers</AttributeValue>
    </Attribute>
</Attributes>
</Request>

Cheers!
Here is my next post, http://pushpalankajaya.blogspot.com/2013/06/xacml-30-policies-restricting.html it discusses a policy that is more restricting than what we tried out so far.

References: Corresponding XACML 2.0 policy - FacileLogin

Popular posts from this blog

Signing SOAP Messages - Generation of Enveloped XML Signatures

Image
Digital signing is a widely used mechanism to make digital contents authentic. By producing a digital signature for some content, we can let another party capable of validating that content. It can provide a guarantee that, is not altered after we signed it, with this validation. With this sample I am to share how to generate the a signature for SOAP envelope. But of course this is valid for any other content signing as well. Here, I will sign The SOAP envelope itself An attachment  Place the signature inside SOAP header  With the placement of signature inside the SOAP header which is also signed by the signature, this becomes a demonstration of enveloped signature. I am using Apache Santuario library for signing. Following is the code segment I used. I have shared the complete sample here to to be downloaded . public static void main(String unused[]) throws Exception {         String keystoreType = "JKS";         Stri...
Read more

Tomcat JDBC Pool - Connection Leak - Catch the Culprit

Database connection leaks are something that can stay hidden unless paid specific attention and would come to the surface at the most critical stages at a peak time of the system. We would manually check if all the open connections have been closed properly. Then we have various code quality plugins that would scan and check for that. Still when the connections are passed through a complex structure of program both of these can miss a possible connection leak. Then at unit test or integration test levels, we can have checks to validate the counts in the connection pool to avoid this unfortunate situation, that would keep engineers busy at year-end, black Friday, etc. :) In the unfortunate case of hitting with a performance degrade or a total crash of the system which can be propagated via a JDBC connection leak, when we suspect a connection leak, how easily and quickly isolate the culprit. In the Tomcat connection pool, we can do this using 3 properties. removeAbandoned If a...
Read more

How to convert WSDL to Java

Image
Background Basically WSDL (Web Services Development Language) is an XML document used to describe or locate web services. WSDL stands for Web Services Description Language. The document describes a Web service. It specifies the location of the service and the operations that can be taken.  WSDL2Java is distributed with Axis2 package of Apache and need to set-up Axis2 to use this service. A  guide to set-up Axis2  can be found in apache organization documents .WSDL 2.0 is the currently using version. Obviously JDK should be properly installed too. Note: For the 3rd method you are not needed to set these things by yourself. The WSDL document includes server Java programs for Web services and generated classes using WSDL2Java feature includes client stubs, server skeletons and data types that can help in writing client side. The generated stub classes play a great role in distributed computing and if you are interested can read on  what are...
Read more