Enterprise JavaBeans 2.1

Introduction

This chapter is concerned with the protection of data against unauthorized access in an Enterprise JavaBeans application. The security of systems for implementation throughout an enterprise is a large and extensive topic. A strategy for addressing the following topics is necessary in the design of such systems:

• Identification of users (authentication);

• Access restriction (authorization);

• Secure data transfer (encryption);

• Management of user data, certification, etc.

The relevant security concepts are components of the Java 2 Enterprise Edition (J2EE) together with certain extensions. The most important extensions of the Java platform in the area of security are the Java Cryptography Extension (JCE; see the reference [30]), the Java Authentication and Authorization Service (JAAS; see [31]), and the Java Secure Socket Extension (JSSE; see [32]).

JCE might be considered a library for data encryption that allows seamless integration of the components of the Java run-time environment into the Java platform via the security API (package java.security.*). JSSE is a library for encrypted data transfer over network sockets (secure socket layer, or SSL), which allows integration into the Java platform as seamless as that of the JCE. Thanks to the flexible architecture of the Java run-time environment (see java.net.SocketImplFactory), normal network sockets can be replaced by secure network sockets of JSSE without the overlying layers being affected. JAAS is a service for the authentication and authorization of users that is provided to an application over a separate API.

A product that supports these security mechanisms enables the configuration and administration of the corresponding services and provides the developer the relevant Java interfaces. These security mechanisms are of a fundamental nature and affect Enterprise JavaBeans only indirectly. This chapter concentrates on the security concepts of the EJB architecture, which are specified for every EJB container by the EJB specification. Extensive information on these topics can be found in [11] and [16]. The EJB security management specification has a distinct focus on flexibility and portability.

In this chapter we consider the following topics:

• Definition of roles: Enterprise Beans work with defined roles, which are mapped to users or user groups. Users and user groups are defined externally to the EJB container.

• Access to the identity of a user and its roles: In the context of every Enterprise Bean (class EJBContext) there are methods available for access to the user. Furthermore, checking of role membership is possible.

• Access protection for methods: For methods of the home and remote home interfaces of an Enterprise Bean one can define the roles that users must possess in order for them to be allowed to call the methods.

• Execution of Enterprise Beans with a defined user context: It is possible to configure an Enterprise Bean in such a way that its methods are not executed in the context of the registered user, but in another user context.

The following sections are devoted to exploring these topics in detail. An overview is given in Figure 8-1.

Figure 8-1: Schematic representation of EJB security.

In addition to the defined security concepts, the EJB container can offer additional services, such as certificate management or a key service. The EJB container offers such services via JNDI in the bean's environment. However, whoever uses such services risks limiting Enterprise Bean portability, since another EJB container may not offer those services, or offer them in a different form.