Multiple Decisions Profile Policy in XACML 3.0

2
votes

I have requirement to write a policy for the particular user it will return the xacml response like this :

This policy is based on single user : bob 

FirstName: Create= true , Read = true, Update = true, Delete = false 
MiddleName:  Create= true , Read = true, Update = true, Delete = false   
LastName: Create= true , Read = true, Update = true, Delete = false

How to write a xacml policy for such requirement and how the request will look like for the same policy.

How to achieve this policy using Axiomatics Alfa plugin and WSO2 identity server.

1
wso2wso2isxacmlxacml3xacml2
You want to retrieve the allowed action for user bob? What is "FirstName, MiddleName, LastName" mean? Could you please explain more? Then I wish, we can provide a better answer. – Asela
BOB is the user in the system , FirstName: BOB , MiddleName :PETER , LastName : MATHEW , so here i need to send a request for the user bob , what are the resources he is allowed to access, suppose bob can Read FirstName but he can't Write i mean to say he can't update his name , so i want to return these values in a response as FirstName: Create= false, Read = true, Update = false, Delete = false . – Utsav
I have one more scenario also to achieve the same for better understanding suppose I have three attributes like 1. Name 2. Age 3. DOB . When the user logged in the application after authentication we initiate the authorization process. So the user can only authorize for accessing these attributes like : Name: {Read=true, Write = "false"}, Age: {Read = true, Write = false}, DOB: {Read =true , Write = false}. So I want to achieve the xacml response like this. For this how the policy structure will look like I don't know. – Utsav

1 Answers

1
votes

Let get as following... This policy is based on single user : bob 

FirstName: Create= true , Read = true, Update = true, Delete = false 
MiddleName:  Create= true , Read = true, Update = false, Delete = false   
LastName: Create= false , Read = true, Update = false, Delete = false

Following is the policy, policy is based on user ("bob"). Therefore we can take the user name as the policy target and can create three rules. In rules, "FirstName", "MiddleName" and "LastName" have been taken as resources and for each resource, rule has been created.

<Policy xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17"  PolicyId="NamePolicy" RuleCombiningAlgId="urn:oasis:names:tc:xacml:1.0:rule-combining-algorithm:first-applicable" Version="1.0">
   <Target>
      <AnyOf>
         <AllOf>
            <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">bob</AttributeValue>
               <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id" Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject" DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"></AttributeDesignator>
            </Match>
         </AllOf>
      </AnyOf>
   </Target>
   <Rule Effect="Permit" RuleId="Rule-1">
      <Target>
         <AnyOf>
            <AllOf>
               <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">FirstName</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>
            </AllOf>
         </AnyOf>
      </Target>
      <Condition>
         <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-at-least-one-member-of">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-bag">
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">create</AttributeValue>
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">update</AttributeValue>
            </Apply>
            <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>
         </Apply>
      </Condition>
   </Rule>
   <Rule Effect="Permit" RuleId="Rule-2">
      <Target>
         <AnyOf>
            <AllOf>
               <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">MiddleName</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>
            </AllOf>
         </AnyOf>
      </Target>
      <Condition>
         <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-at-least-one-member-of">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-bag">
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">create</AttributeValue>
               <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
            </Apply>
            <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>
         </Apply>
      </Condition>
   </Rule>
   <Rule Effect="Permit" RuleId="Rule-3">
      <Target>
         <AnyOf>
            <AllOf>
               <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
                  <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">LastName</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>
            </AllOf>
         </AnyOf>
         <AnyOf>
            <AllOf>
               <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>
   </Rule>
   <Rule Effect="Deny" RuleId="Rule-4"></Rule>
</Policy>

Following is the XACML multiple decision profile request that you can try out. Here, you can change the resource value and see the authorization for each resource. It would return permit result for the actions that are permit for "bob"

<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:resource">
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" IncludeInResult="false">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">LastName</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">bob</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">create</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">update</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">delete</AttributeValue>
      </Attribute>
   </Attributes>
</Request>
<?xml version="1.0" encoding="UTF-8"?>
<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:resource">
      <Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" IncludeInResult="false">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">LastName</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">bob</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">create</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">read</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">update</AttributeValue>
      </Attribute>
   </Attributes>
   <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="true">
         <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">delete</AttributeValue>
      </Attribute>
   </Attributes>
</Request>