Role-based security with embedded TAM


The Java EE role-based authorization model uses the concepts of roles and resources. An example is provided here.


Table 1. Roles

  Methods
Roles getBalance deposit closeAccount
Teller granted granted  
Cashier granted    
Supervisor     granted

In the example of the banking application that is conceptualized in the previous table, three roles are defined: teller, cashier, and supervisor. Permission to perform the getBalance, deposit, and closeAccount application methods are mapped to these roles. From the example, we can see that users assigned the role, Supervisor, can run the closeAccount method, whereas the other two roles are unable to run this method.

The term, principal, within WebSphere Application Sever security refers to a person or a process that performs activities. Groups are logical collections of principals that are configured in WAS to promote the ease of applying security. Roles can be mapped to principals, groups, or both.

The entry that is invoked in the following table indicates that the principal or group can invoke any methods that are granted to that role.
  Roles
Principal/Group Teller Cashier Supervisor
TellerGroup Invoke    
CashierGroup   Invoke  
SupervisorGroup      
Frank: A principal who is not a member of any of the previous groups   Invoke Invoke

In the previous example, the principal Frank, can invoke the getBalance and the closeAccount methods, but cannot invoke the deposit method because this method is not granted either the Cashier or the Supervisor role.

At the time of application deployment, the Java Authorization Contract for Container (JACC) provider of TAM populates the TAM-protected object space with any security policy information contained in the application deployment descriptor and or annotations. This security information is used to determine access whenever the WAS resource is requested.

By default, the TAM access check is performed using the role name, the cell name, the application name, and the module name.

TAM access control lists (ACLs) determine which application roles are assigned to a principal. ACLs are attached to the applications in the TAM-protected object space at the time of application deployment.

Principal-to-role mappings are managed from the WAS admin console and are never modified using TAM. Direct updates to ACLs are performed for administrative security users only.

The following sequence of events occur:

  1. During application deployment, policy information is sent to the JACC provider of TAM . This policy information contains permission-to-role mappings and role-to-principal and role-to-group mapping information.

  2. The JACC provider of TAM converts the information into the required format, and passes this information to the TAM policy server.

  3. The policy server adds entries to the TAM-protected object space to represent the roles defined for the application and the permission-to-role mappings. A permission is represented as a TAM-protected object and the role that is granted to this object is attached as an extended attribute.




 

Related concepts


Authorization providers

 

Related tasks


Administer security users and roles with TAM
Set TAM groups