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J2EE Platform Security Model

factory. For example, the 

javax.sql.DataSource

 interface provides a resource

manager factory interface to obtain a 

javax.sql.Connection

 for a database. JMS,

JavaMail, and URL connection factories are also available for these common types

of resources. 

When integrating with enterprise information systems, J2EE components may

use different security mechanisms and operate in different protection domains

than the resources they access. In these cases, you can configure the calling con 

tainer to manage for the calling component the authentication to the resource, a

form of authentication called 

container managed resource manager sign on

. The

J2EE architecture also recognizes that some components need to directly manage

the specification of caller identity and the production of a suitable authenticator.

For these applications, the J2EE architecture provides a means for an application

component to engage in what is called

 application managed resource manager

sign on

. Use application managed resource manager sign on when the ability to

manipulate the authentication details is fundamental to the component's function 

ality.

The 

resource ref

 elements of a component's deployment descriptor declare

the resources used by the component. The value of the 

res auth 

subelement

declares whether sign on to the resource is managed by the container or the appli 

cation. With application managed resource manager sign on, it is possible for

components that programmatically manage resource sign on to use the

EJBContext.getCallerPrincipal

 or 

HttpServletRequest

.

getUserPrincipal

methods to obtain the identity of their caller. A component can map the identity of

its caller to a new identity or authentication secret as required by the target enter 

prise information system. With container managed resource manager sign on, the

container performs 

principal mapping 

on behalf of the component.

Care should be taken to ensure that access to any component with a capability

to sign on to another resource is secured by appropriate authorization rules. Oth 

erwise, that component can be misused to gain unauthorized access to the

resource.

The J2EE Connector architecture offers a standard API for application 

managed resource manager sign on. This API ensures portability of components

that authenticate with enterprise information systems.

7.2.2 Authorization

Authorization 

mechanisms limit interactions with resources to collections of users

or systems for the purpose of enforcing integrity, confidentiality, or availability