Section 9.10. EJB Security


9.10. EJB Security

To secure the EJB tier, we need to do the following:

  • Deploy the JAAS-based security realm with the JBoss container.

  • Protect the EJB:

    • Allow access to non-secure methods.

    • Configure access to administrative methods.

    • Add security roles.

  • Automate extra ejb-jar.xml settings with XDoclet.

9.10.1. JAAS Domain in jboss.xml

The security domain in jboss.xml defines a security domain used by all EJBs in the application. To join the global security domain for the entire JAW Motors application, the security domain must match the "JawJaasDbRealm" JAAS application name from login-config.xml and the <security-domain> element in jboss-web.xml. The <security-domain> element defines a single security domain used by all EJBs in the application. The <security-domain> element comes before the elements that define the JNDI-based resources. Example 9-13 shows the <security-domain> element in jboss.xml.

Example 9-13. jboss.xml
 <jboss>     <security-domain>java:/jaas/JawJaasDbRealm</security-domain>     ... </jboss> 

The <security-domain> uses java:/jaas/JawJaasDbRealm because it is the JBoss-specific JNDI name used when JBoss deploys the LoginModule as a managed service. The pattern here is that JBoss prefixes its JAAS JNDI names with java:/jaas.

9.10.2. Automating JAAS Domain Settings in jboss.xml

If you recall from the Session Bean chapter, we used XDoclet's Ant <ejbdoclet> task and its <jboss> subtask to generate the J2EE standard ejb-jar.xml and jboss.xml JBoss-specific EJB deployment descriptors, respectively. We now add a securitydomain attribute to the <jboss> subtask in the ejb sub-project's build.xml (Example 9-14) to generate the <security-domain> element in jboss.xml.

Example 9-14. ejb/build.xml
     ...     <ejbdoclet>         ...         <jboss version="4.0" destdir="${gen.source.dir}"                securitydomain="java:/jaas/JawJaasDbRealm"/>     </ejbdoclet>     ... 

9.10.3. Protecting EJBs with ejb-jar.xml

J2EE provides Declarative Security, so we modify ejb-jar.xml in Example 9-15 to configure EJB security.

Example 9-15. ejb-jar.xml
 <enterprise-beans>     <session>         ...         <ejb-name>InventoryFacade</ejb-name>         ...     </session>     ... </enterprise-beans> ...  <!-- Assembly Descriptor -->    <assembly-descriptor>      <security-role>        <role-name>Manager</role-name>      </security-role>      <security-role>        <role-name>guest</role-name>      </security-role>      ...      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>create</method-name>          <method-params>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>create</method-name>          <method-params>          </method-params>        </method>      </method-permission>         <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>listAvailableCars</method-name>          <method-params>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>listAvailableCars</method-name>          <method-params>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>findCar</method-name>          <method-params>             <method-param>int</method-param>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>findCar</method-name>          <method-params>             <method-param>int</method-param>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>deleteCars</method-name>          <method-params>             <method-param>java.lang.String[  ]</method-param>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>deleteCars</method-name>          <method-params>             <method-param>java.lang.String[  ]</method-param>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>saveCar</method-name>          <method-params>             <method-param> com.jbossatwork.dto.CarDTO</method-param>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>saveCar</method-name>          <method-params>             <method-param>com.jbossatwork.dto.CarDTO</method-param>          </method-params>        </method>     </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Local</method-intf>          <method-name>buyCar</method-name>          <method-params>             <method-param>int</method-param>             <method-param>double</method-param>>          </method-params>        </method>      </method-permission>      <method-permission>        <role-name>guest</role-name>        <role-name>Manager</role-name>        <method>          <ejb-name>InventoryFacade</ejb-name>          <method-intf>Remote</method-intf>          <method-name>buyCar</method-name>          <method-params>             <method-param>int</method-param>             <method-param>double</method-param>          </method-params>        </method>     </method-permission>      ... </assembly-descriptor> 

As we did in web.xml, we're creating <security-role> elements for the guest and Manager security roles in the JAW Motors application. The <security-role-ref> elements define the security roles (guest, Manager) for the InventoryFacade Bean. The <method-permission> elements specify that:

  • Only users with the (unauthenticated) guest or (authenticated and authorized) Manager roles can invoke the non-secure create( ), listAvailableCars( ), findCar( ), and buyCar( ) methods when using the Remote and Local Component Interface.

  • Only users with the (authorized) Manager roles can invoke the administrative/secure deleteCars( ) and saveCar( ) method when using the Remote and Local Component Interface.

These security settings in ejb-jar.xml ensure that someone with the Manager role has full access to both the secure and non-secure methods in InventoryFacadeBean, and that a guest user can only create the EJB and access its non-secure methods.

What About EJB-Based Programmatic Security?

The EJB API enables you to go farther with security and add more fine-grained control to resources that use the following methods on javax.ejb.EJBContext:

  • isCallerInRole( )

  • getCallerPrincipal( )

These methods determine the caller's identity or whether she plays a particular role in the system.

We don't want to use Programmatic Security in the EJB Tier for the same reasons why we didn't use it in the Web Tier. We'd rather let the container do the work so we can avoid writing our own infrastructure.


9.10.4. Automating EJB Security Settings with XDoclet

We already have an Ant-based build process that works with XDoclet, so we just have to add a couple of XDoclet tags to the InventoryFacadeBean in Example 9-16 so the Ant build process generates the new security settings in the ejb-jar.xml J2EE standard EJB deployment descriptor.

Example 9-16. InventoryFacadeBean.java
 /**  * ...  *  * @ejb.security-role-ref  *  role-name="Manager"  *  role-link="Manager"  *  * @ejb.security-role-ref  *  role-name="guest"  *  role-link="guest"  */ public class InventoryFacadeBean implements SessionBean {     ...     /**      * @ejb.create-method      * @ejb.permission      *  role-name="guest,Manager"      *      */     public void ejbCreate(  ) throws CreateException {  }     ...     /**      * ...      * @ejb.permission      *  role-name="guest,Manager"      *      */     public List listAvailableCars(  ) throws EJBException {         ...     }     ...     /**      * ...      * @ejb.permission      *  role-name="guest,Manager"      *      */     public CarDTO findCar(int id) throws EJBException {         ...     }     /**      * ...      * @ejb.permission      *  role-name="Manager"      *      */     public void deleteCars(String[  ] ids) throws EJBException {         ...     }     /**      * ...      * @ejb.permission      *  role-name="Manager"      *      */     public void saveCar(CarDTO car) throws EJBException {         ...     }     /**      * ...      * @ejb.permission      *  role-name="guest,Manager"      *      */     public void buyCar(int carId, double price) throws EJBException {         ...     } } 

The class-level @ejb.security-role-ref XDoclet tags associate the InventoryFacade Bean with the Manager security role. The @ejb.permission tag on the ejbCreate( ), listAvailableCars( ), findCar( ), and buyCar( ) methods makes them accessible only to users in the guest and Manager roles. The @ejb.permission tag on the deleteCars( ) and saveCar( ) methods makes them accessible only to users in the Manager role.

9.10.5. Testing Secure EJB Methods

Now that we've propagated the correct user credentials and restricted access to the InventoryFacadeBean's secure methods, let's test our application to ensure that everything still works properly. Here are the steps you should follow to build and deploy the application:

  • Type ant in the root directory of ch09-c to build the project.

  • Shut down JBoss so the Ant script can clean up the JBoss deployment area.

  • Type ant colddeploy to deploy the EAR file (jaw.ear) to the $JBOSS_HOME/server/default/deploy directory.

  • Start JBoss back up.

  • Visit http://localhost:8080/jaw in a web browser.

Click on the "Modify Inventory" link on the JAW Motors home page and everything should work properly.



JBoss at Work. A Practical Guide
JBoss at Work: A Practical Guide
ISBN: 0596007345
EAN: 2147483647
Year: 2004
Pages: 197

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