org.springframework.security.web.authentication.session
Class ConcurrentSessionControlAuthenticationStrategy

java.lang.Object
  org.springframework.security.web.authentication.session.ConcurrentSessionControlAuthenticationStrategy

All Implemented Interfaces:

Aware, MessageSourceAware, SessionAuthenticationStrategy

public class ConcurrentSessionControlAuthenticationStrategy
extends Object
implements MessageSourceAware, SessionAuthenticationStrategy

Strategy which handles concurrent session-control.

When invoked following an authentication, it will check whether the user in question should be allowed to proceed, by comparing the number of sessions they already have active with the configured maximumSessions value. The SessionRegistry is used as the source of data on authenticated users and session data.

If a user has reached the maximum number of permitted sessions, the behaviour depends on the exceptionIfMaxExceeded property. The default behaviour is to expired the least recently used session, which will be invalidated by the ConcurrentSessionFilter if accessed again. If exceptionIfMaxExceeded is set to true, however, the user will be prevented from starting a new authenticated session.

This strategy can be injected into both the SessionManagementFilter and instances of AbstractAuthenticationProcessingFilter (typically UsernamePasswordAuthenticationFilter), but is typically combined with RegisterSessionAuthenticationStrategy using CompositeSessionAuthenticationStrategy.

Since:

3.2

See Also:

CompositeSessionAuthenticationStrategy

Field Summary

protected MessageSourceAccessor

messages

Constructor Summary

ConcurrentSessionControlAuthenticationStrategy(SessionRegistry sessionRegistry)

Method Summary

protected void	allowableSessionsExceeded(List<SessionInformation> sessions, int allowableSessions, SessionRegistry registry) Allows subclasses to customise behaviour when too many sessions are detected.
protected int	getMaximumSessionsForThisUser(Authentication authentication) Method intended for use by subclasses to override the maximum number of sessions that are permitted for a particular authentication.
void	onAuthentication(Authentication authentication, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) In addition to the steps from the superclass, the sessionRegistry will be updated with the new session information.
void	setExceptionIfMaximumExceeded(boolean exceptionIfMaximumExceeded) Sets the exceptionIfMaximumExceeded property, which determines whether the user should be prevented from opening more sessions than allowed.
void	setMaximumSessions(int maximumSessions) Sets the maxSessions property.
void	setMessageSource(MessageSource messageSource) Sets the MessageSource used for reporting errors back to the user when the user has exceeded the maximum number of authentications.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

messages

protected MessageSourceAccessor messages

Constructor Detail

ConcurrentSessionControlAuthenticationStrategy

public ConcurrentSessionControlAuthenticationStrategy(SessionRegistry sessionRegistry)

Parameters:

sessionRegistry - the session registry which should be updated when the authenticated session is changed.

Method Detail

onAuthentication

public void onAuthentication(Authentication authentication,
                             javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response)

In addition to the steps from the superclass, the sessionRegistry will be updated with the new session information.

Specified by:

onAuthentication in interface SessionAuthenticationStrategy

getMaximumSessionsForThisUser

protected int getMaximumSessionsForThisUser(Authentication authentication)

Method intended for use by subclasses to override the maximum number of sessions that are permitted for a particular authentication. The default implementation simply returns the maximumSessions value for the bean.

Parameters:

authentication - to determine the maximum sessions for

Returns:

either -1 meaning unlimited, or a positive integer to limit (never zero)

allowableSessionsExceeded

protected void allowableSessionsExceeded(List<SessionInformation> sessions,
                                         int allowableSessions,
                                         SessionRegistry registry)
                                  throws SessionAuthenticationException

Allows subclasses to customise behaviour when too many sessions are detected.

Parameters:

sessions - either null or all unexpired sessions associated with the principal

allowableSessions - the number of concurrent sessions the user is allowed to have

registry - an instance of the SessionRegistry for subclass use

Throws:

SessionAuthenticationException

setExceptionIfMaximumExceeded

public void setExceptionIfMaximumExceeded(boolean exceptionIfMaximumExceeded)

Sets the exceptionIfMaximumExceeded property, which determines whether the user should be prevented from opening more sessions than allowed. If set to true, a SessionAuthenticationException will be raised which means the user authenticating will be prevented from authenticating. if set to false, the user that has already authenticated will be forcibly logged out.

Parameters:

exceptionIfMaximumExceeded - defaults to false.

setMaximumSessions

public void setMaximumSessions(int maximumSessions)

Sets the maxSessions property. The default value is 1. Use -1 for unlimited sessions.

Parameters:

maximumSessions - the maximimum number of permitted sessions a user can have open simultaneously.

setMessageSource

public void setMessageSource(MessageSource messageSource)

Sets the MessageSource used for reporting errors back to the user when the user has exceeded the maximum number of authentications.

Specified by:

setMessageSource in interface MessageSourceAware