J2EE Security

Chapter 21 of the j2ee spec http://java.sun.com/products/j2ee/

J2ee security can be implemented either as declarative (i.e. entirely in configuration files) or programmatic (i.e. implemented in code, using the Sun API's). Declarative is recommended.

Concepts

Subject - defined by JAAS as "any user of a computing service." Maps roughly onto an Axia "party."

Principal - an entity that can be authenticated, in fact a name that a Subject uses to interact with a service. Each user of the system will typically have a set of Principals which they use to interact with the system. A principal has a Principal Name and Authentication Data. Maps roughly onto an Axia "alias."

Credentials - data or attributes used to authenticate a Principal.

Realm - a set of security policies. Users belong to one realm. The default realm always exists.

Group - a user can be a part of a J2EE group. A J2EE group's scope is the entire J2EE environment.

Security Role - similar to a group, but scope is only within a single application. Roles are declared in the ear file. Each Principal is mapped into one or more roles.

There are two approaches to authorization: capabilities and permissions. Capabilities are user-oriented, i.e. the user can do this or that but not the other. Permissions work the other way. i.e. for this method on this EJB, only these roles can call it.

-- TobyCabot - 30 Jul 2001