java/org/apache/catalina/authenticator/package.html
This package contains Authenticator implementations for the various supported authentication methods (BASIC, DIGEST, and FORM). In addition, there is a convenience base class, AuthenticatorBase, for customized Authenticator implementations.
If you are using the standard context configuration class (org.apache.catalina.startup.ContextConfig) to configure the Authenticator associated with a particular context, you can register the Java class to be used for each possible authentication method by modifying the following Properties file:
src/share/org/apache/catalina/startup/Authenticators.properties
Each of the standard implementations extends a common base class (AuthenticatorBase), which is configured by setting the following JavaBeans properties (with default values in square brackets):
Realm) if this request is part of an HTTP session? [true]The standard authentication methods that are currently provided include: