11 Configuring EJB Application Security

Specifying Users and Groups

OC4J supports the definition of users and groups—either shared by all deployed applications or specific to given applications. You define shared or application-specific users and groups within either the OracleAS JAAS Provider or XML user managers. See the Oracle Application Server Containers for J2EE User's Guide and Oracle Application Server Containers for J2EE Services Guide. for directions.

Specifying Logical Roles in the EJB Deployment Descriptor

As shown in Figure 11-2, you can use a logical name for a role within your bean implementation, and map this logical name to the correct database role or user. The mapping of the logical name to a database role is specified in the OC4J-specific deployment descriptor. See "Mapping Logical Roles to Users and Groups" for more information.

Figure 11-2 Security Mapping

Description of the illustration security2.gif

If you use a logical name for a database role within your bean implementation for methods such as isCallerInRole, you can map the logical name to an actual database role by doing the following:

1. Declare the logical name within the <enterprise-beans> section <security-role-ref> element. For example, to define a role used within the purchase order example, you may have checked, within the bean's implementation, to see if the caller had authorization to sign a purchase order. Thus, the caller would have to be signed in under a correct role. In order for the bean to not need to be aware of database roles, you can check isCallerInRole on a logical name, such as POMgr, since only purchase order managers can sign off on the order. Thus, you would define the logical security role, POMgr within the <security-role-ref><role-name> element within the <enterprise-beans> section, as follows:

   <enterprise-beans>
   ...
     <security-role-ref>
      <role-name>POMgr</role-name>
      <role-link>myMgr</role-link>
     </security-role-ref>
   </enterprise-beans>
   
   

   The <role-link> element within the <security-role-ref> element can be the actual database role, which is defined further within the <assembly-descriptor> section. Alternatively, it can be another logical name, which is still defined more in the <assembly-descriptor> section and is mapped to an actual database role within the Oracle-specific deployment descriptor.

   
   

   Note: The <security-role-ref> element is not required. You only specify it when using security context methods within your bean.

   
   

2. Define the role and the methods that it applies to. In the purchase order example, any method executed within the PurchaseOrder bean must have authorized itself as myMgr. Note that PurchaseOrder is the name declared in the <entity | session><ejb-name> element.

   Thus, the following defines the role as myMgr, the EJB as PurchaseOrder, and all methods by denoting the '*' symbol.

   
   

   Note: The myMgr role in the <security-role> element is the same as the <role-link> element within the <enterprise-beans> section. This ties the logical name of POMgr to the myMgr definition.

   
   

   <assembly-descriptor>
    <security-role>
     <description>Role needed purchase order authorization</description>
     <role-name>myMgr</role-name>
    </security-role>
    <method-permission>
     <role-name>myMgr</role-name>
     <method>
      <ejb-name>PurchaseOrder</ejb-name>
      <method-name>*</method-name>
     </method>
    </method-permission>
   ...
   </assembly-descriptor>
   
   

After performing both steps, you can refer to POMgr within the bean's implementation and the container translates POMgr to myMgr.

The <method-permission><method> element is used to specify the security role for one or more methods within an interface or implementation. According to the EJB specification, this definition can be of one of the following forms:

1. Defining all methods within a bean by specifying the bean name and using the '*' character to denote all methods within the bean, as follows:

   <method-permission>
     <role-name>myMgr</role-name>
     <method>
   	<ejb-name>EJBNAME</ejb-name>
   	<method-name>*</method-name>
     </method>
   </method-permission>
   
   

2. Defining a specific method that is uniquely identified within the bean. Use the appropriate interface name and method name, as follows:

   <method-permission>
     <role-name>myMgr</role-name>
     <method>
   	<ejb-name>myBean</ejb-name>
   	<method-name>myMethodInMyBean</method-name>
     </method>
   </method-permission>
   

   
   

   Note: If there are multiple methods with the same overloaded name, the element of this style refers to all the methods with the overloaded name.

   
   

3. Defining a method with a specific signature among many overloaded versions, as follows:

   <method-permission>
     <role-name>myMgr</role-name>
     <method>
   	<ejb-name>myBean</ejb-name>
   	<method-name>myMethod</method-name>
   	<method-params>
   		<method-param>javax.lang.String</method-param>
   		<method-param>javax.lang.String</method-param>
       	</method-params>
     </method>
   </method-permission>
   
   

   The parameters are the fully-qualified Java types of the method's input parameters. If the method has no input arguments, the <method-params> element contains no elements. Arrays are specified by the array element's type, followed by one or more pair of square brackets, such as int[ ][ ].

Specifying Unchecked Security for EJB Methods

If you want certain methods to not be checked for security roles, you define these methods as unchecked, as follows:

<method-permission>
  <unchecked/>
  <method>
     <ejb-name>EJBNAME</ejb-name>
     <method-name>*</method-name>
  </method>
</method-permission>

Instead of a <role-name> element defined, you define an <unchecked/> element. When executing any methods in the EJBNAME bean, the container does not check for security. Unchecked methods always override any other role definitions.

Specifying the runAs Security Identity

You can specify that all methods of an EJB execute under a specific identity. That is, the container does not check different roles for permission to run specific methods; instead, the container executes all of the EJB methods under the specified security identity. You can specify a particular role or the caller's identity as the security identity.

Specify the runAs security identity in the <security-identity> element, which is contained in the <enterprise-beans> section. The following XML demonstrates that the POMgr is the role under which all the entity bean methods execute.

<enterprise-beans>
 <entity>
 ... 
  <security-identity>
     <run-as>
        <role-name>POMgr</role-name>
     </run-as>
  </security-identity>
...
 </entity>
</enterprise-beans>

Alternatively, the following XML example demonstrates how to specify that all methods of the bean execute under the identity of the caller:

<enterprise-beans>
 <entity>
 ... 
  <security-identity>
     <use-caller-identity/>
  </security-identity>
...
 </entity>
</enterprise-beans>

Mapping Logical Roles to Users and Groups

You can use logical roles or actual users and groups in the EJB deployment descriptor. However, if you use logical roles, you must map them to the actual users and groups defined either in the OracleAS JAAS Provider or XML User Managers.

Map the logical roles defined in the application deployment descriptors to OracleAS JAAS Provider or XML User Manager users or groups through the <security-role-mapping> element in the OC4J-specific deployment descriptor.

• The name attribute of this element defines the logical role that is to be mapped.

• The group or user element maps the logical role to a group or user name. This group or user must be defined in the OracleAS JAAS Provider or XML User Manager configuration. See Oracle Application Server Containers for J2EE User's Guide and Oracle Application Server Containers for J2EE Services Guide for a description of the OracleAS JAAS Provider and XML User Managers.

<security-role-mapping name="POMGR"> 
 <group name="managers" /> 
</security-role-mapping> 

To map this role to a specific user, do the following:

<security-role-mapping name="POMGR"> 
 <user name="guest" /> 
</security-role-mapping> 

Lastly, you can map a role to a specific user within a specific group, as follows:

<security-role-mapping name="POMGR"> 
 <group name="managers" />
 <user name="guest" /> 
</security-role-mapping> 

As shown in Figure 11-3, the logical role name for POMGR defined in the EJB deployment descriptor is mapped to managers within the OC4J-specific deployment descriptor in the <security-role-mapping> element.

Figure 11-3 Security Mapping

Description of the illustration security3.gif

Notice that the <role-name> in the EJB deployment descriptor is the same as the name attribute in the <security-role-mapping> element in the OC4J-specific deployment descriptor. This is what identifies the mapping.

Specifying a Default Role Mapping for Undefined Methods

If any methods have not been associated with a role mapping, they are mapped to the default security role through the <default-method-access> element in the orion-ejb-jar.xml file. The following is the automatic mapping for any insecure methods:

<default-method-access>
   <security-role-mapping name="&lt;default-ejb-caller-role&gt;"
                          impliesAll="true" >
   </security-role-mapping>
</default-method-access>

The default role is <default-ejb-caller-role> and is defined in the name attribute. You can replace this string with any name for the default role. The impliesAll attribute indicates whether any security role checking occurs for these methods. This attribute defaults to true, which states that no security role checking occurs for these methods. If you set this attribute to false, the container will check for this default role on these methods.

If the impliesAll attribute is false, you must map the default role defined in the name attribute to a OracleAS JAAS Provider or XML user or group through the <user> and <group> elements. The following example shows how all methods not associated with a method permission are mapped to the "others" group.

<default-method-access>
   <security-role-mapping name="default-role" impliesAll="false" >
      <group name="others" />
   </security-role-mapping>
</default-method-access>

Specifying Users and Groups by the Client

In order for the client to access methods that are protected by users and groups, the client must provide the correct user or group name with a password that the OracleAS JAAS Provider or XML User Manager recognizes. And the user or group must be the same one as designated in the security role for the intended method. See "Specifying Credentials in EJB Clients" for more information.

Credentials in JNDI Properties

Indicate the username (principal) and password (credentials) to use when looking up remote EJBs in the jndi.properties file.

For example, if you want to access remote EJBs as POMGR/welcome, define the following properties. The factory.initial property indicates that you will use the Oracle JNDI implementation:

java.naming.security.principal=POMGR
java.naming.security.credentials=welcome
java.naming.factory.initial= 	com.evermind.server.ApplicationClientInitialContextFactory
java.naming.provider.url=opmn:ormi://opmnhost:oc4j_inst1/ejbsamples

In your application program, authenticate and access the remote EJBs, as shown below:

InitialContext ic = new InitialContext();
CustomerHome = 	(CustomerHome)ic.lookup("java:comp/env/purchaseOrderBean"); 

Credentials in the InitialContext

To access remote EJBs from a servlet or JavaBean, pass the credentials in the InitialContext object, as follows:

Hashtable env = new Hashtable(); 
env.put("java.naming.provider.url", 	"opmn:ormi://opmnhost:oc4j_inst1/ejbsamples"); 
env.put("java.naming.factory.initial", 
        "com.evermind.server.ApplicationClientInitialContextFactory"); 
env.put(Context.SECURITY_PRINCIPAL, "POMGR"); 
env.put(Context.SECURITY_CREDENTIALS, "welcome"); 
Context ic = new InitialContext (env); 
CustomerHome =  
   (CustomerHome) ic.lookup ("java:comp/env/purchaseOrderBean");