All security attributes are carried in the Credentials object. Credentials is used by LoginModules during the authentication process. The user supplied attributes from LoginModules are accessed by CallbackHandlers. To access the Credentials object, Hazelcast uses its own specialized CallbackHandler. During initialization of LoginModules, Hazelcast passes this special CallbackHandler into the LoginModule.initialize() method.

Your implementation of LoginModule should create an instance of and call the handle(Callback[] callbacks) method of CallbackHandler during the login process.

CredentialsCallback.getCredentials() returns the supplied Credentials object.

public abstract class CustomLoginModule implements LoginModule {

    protected boolean loginSucceeded;
    CallbackHandler callbackHandler;
    Subject subject;
    Credentials credentials;

    public void initialize( Subject subject, CallbackHandler callbackHandler,
                            Map<String, ?> sharedState, Map<String, ?> options ) {
        this.subject = subject;
        this.callbackHandler = callbackHandler;

    public final boolean login() throws LoginException {
        CredentialsCallback callback = new CredentialsCallback();
        try {
            callbackHandler.handle( new Callback[] { callback } );
            credentials = callback.getCredentials();
        } catch ( Exception e ) {
            throw new LoginException( e.getMessage() );
        return loginSucceeded;

To use the default Hazelcast permission policy, you must create an instance of that holds the Credentials object and you must add it to Subject.principals onLoginModule.commit() as shown below.

public class MyCustomLoginModule implements LoginModule {
    public boolean commit() throws LoginException {
        Principal principal = new ClusterPrincipal( credentials );
        subject.getPrincipals().add( principal );
        return true;

Hazelcast has an abstract implementation of LoginModule that does callback and cleanup operations and holds the resulting Credentials instance. LoginModule`s extending `ClusterLoginModule can access Credentials, Subject, LoginModule instances and options and sharedState maps. Extending the ClusterLoginModule is recommended instead of implementing all required stuff.

public abstract class ClusterLoginModule implements LoginModule {
    protected abstract boolean onLogin() throws LoginException;
    protected abstract boolean onCommit() throws LoginException;
    protected abstract boolean onAbort() throws LoginException;
    protected abstract boolean onLogout() throws LoginException;

Enterprise Integration

Using the above API, you can implement a LoginModule that performs authentication against the Security System of your choice, such as an LDAP store like Apache Directory or some other corporate standard you might have. For example, you may wish to have your clients send an identification token in the Credentials object. This token can then be sent to your back-end security system via the LoginModule that runs on the cluster side.

Additionally, the same system may authenticate the user and also then return the roles that are attributed to the user. These roles can then be used for data structure authorization.

See the JAAS Reference Guide for further information.