The Java Authentication and Authorization Service (JAAS) is a pluggable authentication service, which is implemented by a login module. A particular instance of a JAAS service is known as a JAAS realm and is identified by a realm name.

Applications integrated with JAAS must be configured to use a specific realm, by specifying the realm name.

The default realm in Fuse ESB Enterprise is identified by the karaf realm name. The standard administration services in Fuse ESB Enterprise (SSH remote console, JMX port, and so on) are all configured to use the karaf realm by default.

Fuse ESB Enterprise provides the following alternative JAAS realm implementations:

In a standalone container, the karaf realm installs two JAAS login modules, which are used in parallel:

In a fabric, a karaf realm based on the ZookeeperLoginModule login module is automatically installed in every container (the fabric-jaas feature is included in the default profile) and is responsible for securing the SSH remote console and other administrative services. The Zookeeper login module stores the secure user data in the Fabric Registry.

	Note
	In containers where the standalone JAAS realm and the Fabric JAAS realm are both installed, the Fabric JAAS realm takes precedence, because it defines a karaf realm with a higher rank.

It is also possible to configure a container to use an LDAP login module with JAAS. For details of how to set this up, see LDAP Authentication Tutorial in Security Guide.