AuthZForce - User and Programmers Guide

AuthZForce is the reference implementation of the Authorization PDP GE. In this regard, it provides an API to manage XACML-based access control policies and provide authorization decisions based on such policies and the context of a given access request. This guide explains how to use the API.

Background and Detail

This User and Programmers Guide relates to the reference implementation of the Authorization PDP GE which is part of FIWARE Security Architecture. Please find more information about this Generic Enabler in the following Open Specification.

User Guide

Since the Authorization PDP is a Generic Enabler which provides backend functionality to other applications (e.g. Generic Enablers or end user facing applications) and security administrators, we do not distinguish between the User and Programmers Guide. Please refer to the Programmers Guide section for more information.

Programmer Guide

AuthZForce provides the following APIs:

  • PDP API (PDP = Policy Decision Point in the XACML terminology): provides an API for getting authorization decisions computed by a XACML-compliant access control engine;
  • PAP API (PAP = Policy Administration Point in XACML terminology): provides API for managing XACML policies to be handled by the Authorization Service PDP.

The full API (RESTful) is described by a document written in the Web Application Description Language format (WADL) and associated XML schema files available in Authzforce rest-api-model project files.

XACML is the main international OASIS standard for access control language and request-response formats, that addresses most use cases of access control. AuthZForce supports the full core XACML 3.0 language; therefore it allows to enforce very generic and complex access control policies.

Attribute-Based Access Control

AuthZForce provides Attribute-Based Access Control. To understand what is meant by “attribute” in the context of access control, below is the list of categories of attributes identified by the XACML standard:

  • Subject attributes: the subject is an actor (human, program, device, etc.) requesting access to a resource; attributes may be user ID, Organization, Role, Clearance, etc.
  • Resource attributes: the resource is a passive entity (from the access control perspective) on which subject requests to act upon (e.g. data but also human, device, application, etc.); resource attributes may be resource ID, URL, classification, etc.
  • Action attributes: the action is the action that the subject requests to perform on the resource (e.g. create, read, delete); attributes may be action ID, parameter A, parameter B, etc.
  • Environment attributes: anything else, e.g. current time, CPU load of the PEP/PDP, global threat level, etc.

Domain Management API

The API allows AuthZForce application administrators or administration interfaces to create domains for the users, and remove domains once they are no longer used. This part of the API is described in the Installation and Administration guide. The API also allows users to update certain properties of the domain allocated to them:

  • An externalId (optional) for the domain, which users/clients can modify and more easily use as reference, as opposed to the unique and read-only domain ID assigned by the API - once and for all - when the domain is created;
  • Root policy reference (mandatory): a policy ID and version constraints expected to match one of the domain’s policies and used as the root policy enforced by the domain’s PDP. These policies are managed via the Policy Administration API described in the next section;
  • A description of the domain (optional).

You may retrieve the current domain properties as follows:

  • Method: GET

  • Path: /domains/{domainId}/properties

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example, this request gets the properties of domain iMnxv7sDEeWFwqVFFMDLTQ, i.e. its externalId and root policy reference. This reference points to some policy PolicyABC that must exist in the domain (added via the PAP API mentioned later) as a prerequisite:

 GET /domains/iMnxv7sDEeWFwqVFFMDLTQ/properties
 HTTP/1.1
 Accept: application/xml; charset=UTF-8

 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <ns4:domainProperties
  xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4">
  <rootPolicyRef Version="1.0">PolicyABC</rootPolicyRef>
</ns4:domainProperties>

You may update the domain properties as follows:

  • Method: PUT

  • Path: /domains/{domainId}/properties

  • Headers:

    • Content-Type: application/xml; charset=UTF-8
    • Accept: application/xml; charset=UTF-8

  • Body: new properties.

For example, this request sets/updates the externalId to my-domain-123 and the root policy reference to some policy PolicyABC (in version 2.1) that must exist in the domain (added via the PAP API mentioned later) as a prerequisite:

PUT /domains/iMnxv7sDEeWFwqVFFMDLTQ/properties
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:domainProperties
  xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4" externalId="my-domain-123">
  <rootPolicyRef Version="2.1">PolicyDEF</rootPolicyRef>
</ns4:domainProperties>

Note that the Version attribute is optional here. If omitted, the latest version available is used. The response is the new properties.

As a result, the policy now enforced by the domain’s Policy Decision Point (see the PDP API in the last section of this document) is PolicyABC (in version 2.1) and the domain’s external ID my-domain-123 points to the domain iMnxv7sDEeWFwqVFFMDLTQ. Clients may only rely on the externalId under their control to recover the API-defined domain ID, before they begin to use other API operations that require the API-defined domain ID. Indeed, clients may request the API-defined ID corresponding to a given externalId as follows:

GET /domains?externalId=my-domain-123
HTTP/1.1
Accept: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:resources
    xmlns:ns2="http://authzforce.github.io/rest-api-model/xmlns/authz/4"
    xmlns:ns3="http://www.w3.org/2005/Atom">
    <ns3:link rel="item" href="iMnxv7sDEeWFwqVFFMDLTQ" title="iMnxv7sDEeWFwqVFFMDLTQ"/>
</ns2:resources>

Policy Administration API

The PAP is used by policy administrators to manage the policy repository from which the PDP loads the enforced policies. The PAP supports multi-tenancy in the form of generic administration domains that are separate from each other. Each policy administator (except the Superadmin) is in fact a domain administrator, insofar as he is allowed to manage the policy for one or more specific domains. Domains are typically used to support isolation of tenants (one domain per tenant).

Adding Policies

The PAP provides a RESTful API for adding policies to a specific domain. HTTP requests to this API must be formatted as follows:

  • Method: POST

  • Path: /domains/{domainId}/pap/policies

  • Headers:

    • Content-Type: application/xml; charset=UTF-8
    • Accept: application/xml; charset=UTF-8

  • Body: XACML PolicySet as defined in the XACML 3.0 schema.

Example of request given below:

POST /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<PolicySet xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17" PolicySetId="P1"
 Version="1.0"
 PolicyCombiningAlgId="urn:oasis:names:tc:xacml:3.0:policy-combining-algorithm:deny-unless-permit">
 <Description>Sample PolicySet</Description>
 <Target />
 <Policy PolicyId="MissionManagementApp" Version="1.0"
  RuleCombiningAlgId="urn:oasis:names:tc:xacml:3.0:rule-combining-algorithm:deny-unless-permit">
  <Description>Policy for MissionManagementApp</Description>
  <Target>
   <AnyOf>
    <AllOf>
     <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
      <AttributeValue
       DataType="http://www.w3.org/2001/XMLSchema#string">MissionManagementApp</AttributeValue>
       <AttributeDesignator
        Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource"
        AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
        DataType="http://www.w3.org/2001/XMLSchema#string"
        MustBePresent="true" />
      </Match>
     </AllOf>
    </AnyOf>
   </Target>
  <Rule RuleId="MissionManager_role_can_manage_team" Effect="Permit">
   <Description>Only MissionManager role authorized to manage the mission team</Description>
   <Target>
    <AnyOf>
     <AllOf>
      <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
       <AttributeValue
        DataType="http://www.w3.org/2001/XMLSchema#string">Team</AttributeValue>
       <AttributeDesignator
        Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource"
        AttributeId="urn:thales:xacml:2.0:resource:sub-resource-id"
        DataType="http://www.w3.org/2001/XMLSchema#string"
        MustBePresent="true" />
      </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">manage</AttributeValue>
       <AttributeDesignator
        Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action"
        AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
        DataType="http://www.w3.org/2001/XMLSchema#string"
        MustBePresent="true" />
      </Match>
     </AllOf>
    </AnyOf>
   </Target> <Condition>
    <Apply FunctionId="urn:oasis:names:tc:xacml:3.0:function:any-of">
     <Function FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal" />
      <AttributeValue
       DataType="http://www.w3.org/2001/XMLSchema#string">MissionManager</AttributeValue>
      <AttributeDesignator AttributeId="urn:oasis:names:tc:xacml:2.0:subject:role"
       DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="false"
       Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject" />
    </Apply>
   </Condition>
  </Rule>
 </Policy>
</PolicySet>

The HTTP response status is 200 with a link to manage the new policy, if the request was successfull. The link is made of the policy ID and version separated by ‘/’.

Response:

HTTP/1.1 200 OK
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns3:link xmlns:ns3="http://www.w3.org/2005/Atom"
  rel="item" href="P1/1.0" title="Policy 'P1' v1.0"/>

Getting Policies and Policy Versions

Once added to the domain as shown previously, you can get the policy by its ID as follows:

  • Method: GET

  • Path: /domains/{domainId}/pap/policies/{policyId}

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example:

GET /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies/P1
HTTP/1.1
Accept: application/xml; charset=UTF-8

The response is the list of links to the versions of the policy available in the domain:

HTTP/1.1 200 OK
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:resources
  xmlns:ns2="http://authzforce.github.io/rest-api-model/xmlns/authz/4"
  xmlns:ns3="http://www.w3.org/2005/Atom">
    <ns3:link rel="item" href="1.0"/>
    <ns3:link rel="item" href="1.1"/>
    <ns3:link rel="item" href="2.0"/>
    <ns3:link rel="item" href="2.1"/>
    <ns3:link rel="item" href="2.2"/>
    ...
</ns2:resources>

Therefore, you may get a specific version of the policy as follows:

  • Method: GET

  • Path: /domains/{domainId}/pap/policies/{policyId}/{version}

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example:

GET /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies/P1/1.0
HTTP/1.1
Accept: application/xml; charset=UTF-8

The response is the policy document (XACML PolicySet) in this version.

Last but not least, you may get all policies in the domain as follows:

  • Method: GET

  • Path: /domains/{domainId}/pap/policies

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example:

GET /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies
HTTP/1.1
Accept: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns2:resources
  xmlns:ns2="http://authzforce.github.io/rest-api-model/xmlns/authz/4"
  xmlns:ns3="http://www.w3.org/2005/Atom">
    <ns3:link rel="item" href="root"/>
    <ns3:link rel="item" href="P1"/>
    <ns3:link rel="item" href="P2"/>
    ...
</ns2:resources>

Removing Policies and Policy Versions

You may remove a policy version from the domain as follows:

  • Method: DELETE

  • Path: /domains/{domainId}/pap/policies/{policyId}/{version}

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example:

DELETE /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies/P1/1.0
HTTP/1.1
Accept: application/xml; charset=UTF-8

The response is the removed policy document (XACML PolicySet) in this version.

You may remove all versions of a policy from the domain as follows:

  • Method: DELETE

  • Path: /domains/{domainId}/pap/policies/{policyId}

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example:

DELETE /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies/P1
HTTP/1.1
Accept: application/xml; charset=UTF-8

The response is the list of links to all the removed versions of the policy, similar to the the GET request on the same URL.

Re-usable Policies (e.g. for Hierarchical RBAC)

The PAP API supports policies that have references to other policies existing in the domain. This allows to include/reuse a given policy from multiple policies, or multiple parts of the same policy, by means of XACML <PolicySetIdReference> elements. One major application of this is Hierarchical RBAC. You can refer to the Core and hierarchical role based access control (RBAC) profile of XACML v3.0 specification for how to achieve hierarchical RBAC with <PolicySetIdReference> elements.

For example, I want to define a role Employee and a role Manager derived from Employee. In other words, permissions of an Employee are included in the permissions of a Manager.

In order to create this role hierarchy, we first add the Employee’s Permission PolicySet:

POST /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8"?>
<PolicySet PolicySetId="PPS:Employee" Version="1.0"
 PolicyCombiningAlgId="urn:oasis:names:tc:xacml:3.0:policy-combining-algorithm:deny-unless-permit">
 <Description>Permissions specific to the Employee role</Description>
 <Target />
 <Policy PolicyId="PP:Employee" Version="1.0"
  RuleCombiningAlgId="urn:oasis:names:tc:xacml:3.0:rule-combining-algorithm:deny-unless-permit">
  <Target />
  <Rule RuleId="Permission_to_create_issue_ticket" Effect="Permit">
   <Target>
    <AnyOf>
     <AllOf>
      <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
       <AttributeValue
        DataType="http://www.w3.org/2001/XMLSchema#string">https://acme.com/tickets</AttributeValue>
       <AttributeDesignator Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource"
        AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
        DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true" />
      </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">POST</AttributeValue>
       <AttributeDesignator
        Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action"
        AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
        DataType="http://www.w3.org/2001/XMLSchema#string"
        MustBePresent="true" />
      </Match>
     </AllOf>
    </AnyOf>
   </Target>
  </Rule>
 </Policy>
</PolicySet>

Then we add the role-based hierarchical policy defining the Employee role and the Manager role, both with a reference (<PolicySetIdReference>) to the Employee’s Permission PolicySet added previously; except the Manager role one policy more, so more permissions:

POST /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/policies
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<PolicySet xmlns="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" PolicySetId="rbac:policyset" Version="1.0"
 PolicyCombiningAlgId="urn:oasis:names:tc:xacml:3.0:policy-combining-algorithm:deny-unless-permit">
 <Description>Root PolicySet</Description>
 <Target />
 <PolicySet PolicySetId="RPS:Employee" Version="1.0"
  PolicyCombiningAlgId="urn:oasis:names:tc:xacml:3.0:policy-combining-algorithm:deny-unless-permit">
  <Description>Employee Role PolicySet</Description> <Target>
   <AnyOf>
    <AllOf>
     <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
      <AttributeValue
       DataType="http://www.w3.org/2001/XMLSchema#string">Employee</AttributeValue>
      <AttributeDesignator
       Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject"
       AttributeId="urn:oasis:names:tc:xacml:2.0:subject:role"
       DataType="http://www.w3.org/2001/XMLSchema#string"
       MustBePresent="true" />
     </Match>
    </AllOf>
   </AnyOf>
  </Target>
  <PolicySetIdReference>PPS:Employee</PolicySetIdReference>
 </PolicySet>
 <PolicySet PolicySetId="RPS:Manager" Version="1.0"
  PolicyCombiningAlgId="urn:oasis:names:tc:xacml:3.0:policy-combining-algorithm:deny-unless-permit">
  <Description>Manager Role PolicySet</Description>
  <Target>
   <AnyOf>
    <AllOf>
     <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
      <AttributeValue DataType="http://www.w3.org/2001/XMLSchema#string">Manager</AttributeValue>
      <AttributeDesignator
       Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject"
       AttributeId="urn:oasis:names:tc:xacml:2.0:subject:role"
       DataType="http://www.w3.org/2001/XMLSchema#string"
       MustBePresent="true" />
     </Match>
    </AllOf>
   </AnyOf>
  </Target>
  <Policy PolicyId="PP1:Manager" Version="1.0"
   RuleCombiningAlgId="urn:oasis:names:tc:xacml:3.0:rule-combining-algorithm:deny-unless-permit">
   <Description>Permissions specific to Manager Role</Description>
   <Target />
   <Rule
   RuleId="Permission_to_create_new_project" Effect="Permit">
    <Target>
     <AnyOf>
      <AllOf>
       <Match MatchId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
        <AttributeValue
         DataType="http://www.w3.org/2001/XMLSchema#string">https://acme.com/projects</AttributeValue>
        <AttributeDesignator
         Category="urn:oasis:names:tc:xacml:3.0:attribute-category:resource"
         AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
         DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true" />
       </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">POST</AttributeValue>
        <AttributeDesignator
         Category="urn:oasis:names:tc:xacml:3.0:attribute-category:action"
         AttributeId="urn:oasis:names:tc:xacml:1.0:action:action-id"
         DataType="http://www.w3.org/2001/XMLSchema#string" MustBePresent="true"/>
       </Match>
      </AllOf>
     </AnyOf>
    </Target>
   </Rule>
  </Policy>
  <!-- This role is senior to the Employee role, therefore includes the Employee role Permission
   PolicySet -->
  <PolicySetIdReference>PPS:Employee</PolicySetIdReference>
 </PolicySet>
</PolicySet>

You may add more policies for more roles as you wish. Once you are satisfied with your role hierarchy, you may apply your new RBAC policy by updating the domain’s root policy reference (this may not be necessary if you reused the same root policy ID as before, in which case your policy is already active by now):

PUT /domains/iMnxv7sDEeWFwqVFFMDLTQ/properties
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:domainProperties xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4">
  <rootPolicyRef>rbac:policyset</rootPolicyRef>
</ns4:domainProperties>

The policy is now enforced by the PDP as described in the next section.

Attribute Providers

The API allows to manage PDP attribute providers. These are PDP extensions that enable the PDP to get attributes from other sources than PEPs’ requests. Such sources may be remote services, databases, etc. The AuthZForce Server distribution does not provide attribute providers out of the box, but allows you to plug in custom-made one(s) from your own invention or from third parties. The AuthZForce project also provides a separate Attribute Provider example, for testing and documentation purposes only. If you wish to make your own attribute provider, read on the next section. If you wish to test the example provided by AuthZForce or have another one ready for use, you may jump to the section Integrating an Attribute Provider into AuthZForce Server.

Making an Attribute Provider

The steps to make your own PDP Attribute Provider extension for AuthZForce go as follows:

  1. Create a Maven project with jar packaging type.

  2. Create an XML schema file with .xsd extension in the src/main/resources folder of your Maven project. Make sure this filename is potentially unique on a Java classpath, like your usual Java class names. One way to make sure is to use a filename prefix following the same conventions as the Java package naming conventions. In this schema file, define an XML type for your attribute provider configuration format. This type must extend AbstractAttributeProvider from namespace http://authzforce.github.io/xmlns/pdp/ext/3. You may use the schema of AuthZForce Test Attribute Provider (used for AuthZForce unit tests only) as an example. In this example, the XSD filename is org.ow2.authzforce.core.test.xsd and the defined XML type extending AbstractAttributeProvider is TestAttributeProvider.

  3. Copy the files bindings.xjb and catalog.xml from Authzforce source code into the src/main/jaxb folder (you have to create this folder first) of your Maven project.

  4. Add the following Maven dependency and build plugin configuration to your Maven POM:

    ...
<dependencies>
 <dependency>
  <groupId>org.ow2.authzforce</groupId>
  <artifactId>authzforce-ce-core-pdp-api</artifactId>
  <version>3.6.1</version>
 </dependency>
 ...
</dependencies>
...

<build>
 ...
 <plugins>
  <plugin>
   <groupId>org.jvnet.jaxb2.maven2</groupId>
   <artifactId>maven-jaxb2-plugin</artifactId>
   <version>0.13.0</version>
   <configuration>
    <debug>false</debug>
    <strict>false</strict>
    <verbose>false</verbose>
    <removeOldOutput>true</removeOldOutput>
    <extension>true</extension>
    <useDependenciesAsEpisodes>false</useDependenciesAsEpisodes>
    <episodes>
     <episode>
      <groupId>org.ow2.authzforce</groupId>
      <artifactId>authzforce-ce-pdp-ext-model</artifactId>
      <version>3.3.7</version>
     </episode>
    </episodes>
    <catalog>src/main/jaxb/catalog.xml</catalog>
    <bindingDirectory>src/main/jaxb</bindingDirectory>
    <schemaDirectory>src/main/resources</schemaDirectory>
   </configuration>
  </plugin>
  ...
 </plugins>
</build>
...

  5. Run Maven generate-sources. This will generate the JAXB-annotated class(es) from the XML schema into the folder target/generated-sources/xjc, one of which corresponds to your attribute provider XML type defined in the second step, therefore has the same name and also extends org.ow2.authzforce.xmlns.pdp.ext.AbstractAttributeProvider class corresponding to AbstractAttributeProvider type in the XML schema. For example, in the case of the Authzforce Test Attribute Provider aforementioned, the corresponding generated class is org.ow2.authzforce.core.xmlns.test.TestAttributeProvider. In your case and in general, we will refer to it as your Attribute Provider Model Class.

  6. Create your Attribute Provider factory and concrete implementation class (as in the Factory design pattern). The Java class must extend org.ow2.authzforce.core.pdp.api.CloseableAttributeProviderModule.FactoryBuilder<APM>, where APM stands for your Attribute Provider Model Class. You may use the AuthZForce TestAttributeProviderModule class (used for AuthZForce unit tests only) as an example. In this example, the static nested class Factory is the one extending CloseableAttributeProviderModule.FactoryBuilder<TestAttributeProvider>. Such a class has a factory method getInstance(APM configuration) (getInstance(TestAttributeProvider conf) in the example) that, from an instance of your APM representing the XML input (TestAttributeProvider in the example), creates an instance of your Attribute Provider implementation class (TestAttributeProviderModule in the example). The latter must implement a method get(attributeGUID, attributeDatatype, context)) in charge of actually retrieving the extra attributes (TestAttributeProviderModule#get(...) in the example). The attributeGUID identifies an XACML attribute category, ID and Issuer that the PDP is requesting from your attribute provider; the attributeDatatype is the expected attribute datatype; and context is the request context, including the content from the current XACML Request and possibly extra attributes retrieved so far by other Attribute Providers.

  7. When your implementation class is ready, create a text file org.ow2.authzforce.core.pdp.api.PdpExtension in folder src/main/resources/META-INF/services (you have to create the folder first) and put the fully qualified name of your implementation class on the first line of this file, like in the example from Authzforce source code.

  8. Run Maven package to produce a JAR from the Maven project.

Now you have an Attribute Provider extension ready for integration into AuthZForce Server, as explained in the next section.

Integrating an Attribute Provider into AuthZForce Server

This section assumes you have an Attribute Provider extension in form of a JAR, typically produced by the process in the previous section. You may use AuthZForce Test Attribute Provider JAR if you only wish to test the examples in this documentation. This JAR is available on Maven Central with the following artifact information: groupId org.ow2.authzforce, artifactId authzforce-ce-core, version 3.7.0, packaging jar, classifier tests.

The steps to integrate the extension into the AuthZForce Server go as follows:

  1. Make the JAR - and any extra dependency - visible from the AuthZForce webapp in Tomcat. One way to do it consists to copy the JAR (e.g. authzforce-ce-core-3.7.0-tests.jar in our example) into /opt/authzforce-ce-server/webapp/WEB-INF/lib. For other ways, please refer to Tomcat HowTo.

  2. Import your attribute provider XML schema in the XML schema file /opt/authzforce-ce-server/conf/authzforce-ext.xsd, using namespace only (no schemaLocation), like in the example from Authzforce code with this schema import for Authzforce TestAttributeProvider:

    <xs:import namespace="http://authzforce.github.io/core/xmlns/test/3" />

  3. Add a uri element to XML catalog file /opt/authzforce-ce-server/conf/catalog.xml, with your attribute Provider XML namespace as name attribute value, and, the location of your XML schema file within the JAR, as uri attribute value, prefixed by classpath:. For example, in the sample XML catalog from Authzforce source code, we add the following line for Authzforce TestAttributeProvider:

    <uri name="http://authzforce.github.io/core/xmlns/test/3" uri="classpath:org.ow2.authzforce.core.test.xsd"/>

  4. Finally, restart Tomcat to apply changes.

Managing attribute providers configuration

Once you have deployed a new attribute provider extension on Authzforce, following previous instructions, you are ready to use it on a domain:

  • Method: PUT

  • Path: /domains/{domainId}/pap/attributeProviders

  • Headers:

    • Content-Type: application/xml; charset=UTF-8
    • Accept: application/xml; charset=UTF-8

  • Body: new attribute providers.

For example, this request instantiates a specific TestAttributeProvider configuration on domain iMnxv7sDEeWFwqVFFMDLTQ (as mentioned in the previous section, TestAttributeProvider is merely an example for testing and documentation purposes, it is not available in a default installation of Authzforce):

PUT /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/attributeProviders
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:attributeProviders
 xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4"
 xmlns:ns3="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17">
 <attributeProvider
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:ns5="http://authzforce.github.io/core/xmlns/test/3"
  xsi:type="ns5:TestAttributeProvider" id="test">
  <ns3:Attributes
  Category="urn:oasis:names:tc:xacml:1.0:subject-category:access-subject">
   <ns3:Attribute AttributeId="urn:oasis:names:tc:xacml:1.0:example:attribute:role"
    IncludeInResult="false">
    <ns3:AttributeValue
     DataType="http://www.w3.org/2001/XMLSchema#string">Physician</ns3:AttributeValue>
   </ns3:Attribute>
  </ns3:Attributes>
 </attributeProvider>
</ns4:attributeProviders>

The response is the new attribute provider configuration from the request.

In this second example, we disable all PDP attribute providers of domain iMnxv7sDEeWFwqVFFMDLTQ by sending an empty element:

PUT /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/attributeProviders
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:attributeProviders xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4" />

Finally, you may get the current attribute providers anytime as follows:

  • Method: GET

  • Path: /domains/{domainId}/pap/attributeProviders

  • Headers:

    • Accept: application/xml; charset=UTF-8

For example, this request gets the PDP attribute providers of domain iMnxv7sDEeWFwqVFFMDLTQ:

GET /domains/iMnxv7sDEeWFwqVFFMDLTQ/pap/attributeProviders
HTTP/1.1
Accept: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:attributeProviders xmlns:ns4="http://authzforce.github.io/rest-api-model/xmlns/authz/4">
  ...
</ns4:attributeProviders>

Policy Decision API

The PDP API returns an authorization decision based on the currently enforced policy, access control attributes provided in the request and possibly other attributes resolved by the PDP itself. The Authorization decision is typically Permit or Deny. The PDP is able to resolve extra attributes not provided directly in the request, such as the current date/time (environment attribute).

The PDP provides an HTTP RESTful API for requesting authorization decisions. The HTTP request must be formatted as follows:

  • Method: POST

  • Path: /domains/{domainId}/pdp

  • Headers:

    • Content-Type: application/xml; charset=UTF-8
    • Accept: application/xml; charset=UTF-8

  • Body: XACML Request as defined in the XACML 3.0 schema.

The HTTP response body is a XACML Response as defined in the XACML 3.0 schema.

Example of request given below:

POST /domains/iMnxv7sDEeWFwqVFFMDLTQ/pdp
HTTP/1.1
Accept: application/xml; charset=UTF-8
Content-Type: application/xml; charset=UTF-8

<?xml version='1.0' encoding='UTF-8' standalone='yes'?>
<Request xmlns='urn:oasis:names:tc:xacml:3.0:core:schema:wd-17'
 CombinedDecision="false" ReturnPolicyIdList="false">
 <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'>joe</AttributeValue>
  </Attribute>
  <Attribute AttributeId="urn:oasis:names:tc:xacml:2.0:subject:role"
   IncludeInResult="false"> <AttributeValue
    DataType='http://www.w3.org/2001/XMLSchema#string'>Manager</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'>MissionManagementApp</AttributeValue>
  </Attribute>
  <Attribute
   AttributeId='urn:thales:xacml:2.0:resource:sub-resource-id' IncludeInResult="false">
   <AttributeValue
   DataType='http://www.w3.org/2001/XMLSchema#string'>Team</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="false">
   <AttributeValue
    DataType='http://www.w3.org/2001/XMLSchema#string'>manage</AttributeValue>
  </Attribute>
 </Attributes>
 <Attributes
  Category="urn:oasis:names:tc:xacml:3.0:attribute-category:environment" />
</Request>

Response:

HTTP/1.1 200 OK
Content-Type: application/xml; charset=UTF-8

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns1:Response xmlns:ns1="urn:oasis:names:tc:xacml:3.0:core:schema:wd-17" ...>
   <ns1:Result>
       <ns1:Decision>Permit</ns1:Decision>
   </ns1:Result>
</ns1:Response>

Note for developers parsing XML manually or with namespace-UNaware parsers: the namespace prefix of the Response element - ns1 in this example - might vary from a run time to another, but it is always the same XML element as the prefix is always mapped to urn:oasis:names:tc:xacml:3.0:core:schema:wd-17 (XACML 3.0 namespace). Therefore, any valid (namespace-aware) XML parser will handle it equally, no matter what the namespace prefix is.

Integration with the IdM and PEP Proxy GEs (e.g. for OAuth)

AuthZForce integrates with the Identity Management (KeyRock) and PEP Proxy GE (Wilma) reference implementations. For an overview of the main interactions, please refer to the Basic and Advanced sections of Wilma programmer guide.

After you installed and configured KeyRock, to connect it to Authzforce, you modify the properties with names prefixed by ACCESS_CONTROL_ in the configuration file fiware-idm/horizon/openstack_dashboard/local/local_settings.py (example on KeyRock Github repository) according to your AuthZForce instance properties. Then go to IdM web interface, and check that the permissions and roles are well configured for your application. You may have to ‘trigger’ the policy generation in IdM by going to your application > Manage roles and click Save to trigger the XACML generation. More information in KeyRock installation and administration guide.

Then, after you installed and configured Wilma, to connect it to Authzforce, you modify the settings in config.azf object of configuration file config.js (example) according to your AuthZForce instance properties. More information in Wilma installation and administration guide.

Software Libraries for clients of AuthZForce or other Authorization PDP GEis

The full API (RESTful) is described by a document written in the Web Application Description Language format (WADL) and associated XML schema files available in Authzforce rest-api-model project files. Therefore, you can use any WADL-supporting REST framework for clients; for instance in Java: Jersey, Apache CXF. From that, you can use WADL-to-code generators to generate your client code. For example in Java, ‘wadl2java’ tools allow to generate code for JAX-RS compatible frameworks such as Apache CXF and Jersey. Actually, we can provide a CXF-based Java library created with this tool to facilitate the development of clients.