org.springframework.security.cas.web
Class CasAuthenticationFilter

java.lang.Object
  org.springframework.web.filter.GenericFilterBean
      org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter
          org.springframework.security.cas.web.CasAuthenticationFilter

All Implemented Interfaces:

javax.servlet.Filter, Aware, BeanNameAware, DisposableBean, InitializingBean, ApplicationEventPublisherAware, EnvironmentAware, MessageSourceAware, ServletContextAware

public class CasAuthenticationFilter
extends AbstractAuthenticationProcessingFilter

Processes a CAS service ticket, obtains proxy granting tickets, and processes proxy tickets.

Service Tickets

A service ticket consists of an opaque ticket string. It arrives at this filter by the user's browser successfully authenticating using CAS, and then receiving a HTTP redirect to a service. The opaque ticket string is presented in the ticket request parameter.

This filter monitors the service URL so it can receive the service ticket and process it. By default this filter processes the URL /j_spring_cas_security_check. When processing this URL, the value of ServiceProperties.getService() is used as the service when validating the ticket. This means that it is important that ServiceProperties.getService() specifies the same value as the filterProcessesUrl.

Processing the service ticket involves creating a UsernamePasswordAuthenticationToken which uses CAS_STATEFUL_IDENTIFIER for the principal and the opaque ticket string as the credentials.

Obtaining Proxy Granting Tickets

If specified, the filter can also monitor the proxyReceptorUrl. The filter will respond to requests matching this url so that the CAS Server can provide a PGT to the filter. Note that in addition to the proxyReceptorUrl a non-null proxyGrantingTicketStorage must be provided in order for the filter to respond to proxy receptor requests. By configuring a shared ProxyGrantingTicketStorage between the TicketValidator and the CasAuthenticationFilter one can have the CasAuthenticationFilter handle the proxying requirements for CAS.

Proxy Tickets

The filter can process tickets present on any url. This is useful when wanting to process proxy tickets. In order for proxy tickets to get processed ServiceProperties.isAuthenticateAllArtifacts() must return true. Additionally, if the request is already authenticated, authentication will not occur. Last, AuthenticationDetailsSource.buildDetails(Object) must return a ServiceAuthenticationDetails. This can be accomplished using the ServiceAuthenticationDetailsSource. In this case ServiceAuthenticationDetails.getServiceUrl() will be used for the service url.

Processing the proxy ticket involves creating a UsernamePasswordAuthenticationToken which uses CAS_STATELESS_IDENTIFIER for the principal and the opaque ticket string as the credentials. When a proxy ticket is successfully authenticated, the FilterChain continues and the authenticationSuccessHandler is not used.

Notes about the AuthenticationManager

The configured AuthenticationManager is expected to provide a provider that can recognise UsernamePasswordAuthenticationTokens containing this special principal name, and process them accordingly by validation with the CAS server. Additionally, it should be capable of using the result of ServiceAuthenticationDetails.getServiceUrl() as the service when validating the ticket.

Example Configuration

An example configuration that supports service tickets, obtaining proxy granting tickets, and proxy tickets is illustrated below:

 <b:bean id="serviceProperties"
     class="org.springframework.security.cas.ServiceProperties"
     p:service="https://service.example.com/cas-sample/j_spring_cas_security_check"
     p:authenticateAllArtifacts="true"/>
 <b:bean id="casEntryPoint"
     class="org.springframework.security.cas.web.CasAuthenticationEntryPoint"
     p:serviceProperties-ref="serviceProperties" p:loginUrl="https://login.example.org/cas/login" />
 <b:bean id="casFilter"
     class="org.springframework.security.cas.web.CasAuthenticationFilter"
     p:authenticationManager-ref="authManager"
     p:serviceProperties-ref="serviceProperties"
     p:proxyGrantingTicketStorage-ref="pgtStorage"
     p:proxyReceptorUrl="/j_spring_cas_security_proxyreceptor">
     <b:property name="authenticationDetailsSource">
         <b:bean class="org.springframework.security.cas.web.authentication.ServiceAuthenticationDetailsSource"/>
     </b:property>
     <b:property name="authenticationFailureHandler">
         <b:bean class="org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler"
             p:defaultFailureUrl="/casfailed.jsp"/>
     </b:property>
 </b:bean>
 <!--
     NOTE: In a real application you should not use an in memory implementation. You will also want
           to ensure to clean up expired tickets by calling ProxyGrantingTicketStorage.cleanup()
  -->
 <b:bean id="pgtStorage" class="org.jasig.cas.client.proxy.ProxyGrantingTicketStorageImpl"/>
 <b:bean id="casAuthProvider" class="org.springframework.security.cas.authentication.CasAuthenticationProvider"
     p:serviceProperties-ref="serviceProperties"
     p:key="casAuthProviderKey">
     <b:property name="authenticationUserDetailsService">
         <b:bean
             class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">
             <b:constructor-arg ref="userService" />
         </b:bean>
     </b:property>
     <b:property name="ticketValidator">
         <b:bean
             class="org.jasig.cas.client.validation.Cas20ProxyTicketValidator"
             p:acceptAnyProxy="true"
             p:proxyCallbackUrl="https://service.example.com/cas-sample/j_spring_cas_security_proxyreceptor"
             p:proxyGrantingTicketStorage-ref="pgtStorage">
             <b:constructor-arg value="https://login.example.org/cas" />
         </b:bean>
     </b:property>
     <b:property name="statelessTicketCache">
         <b:bean class="org.springframework.security.cas.authentication.EhCacheBasedTicketCache">
             <b:property name="cache">
                 <b:bean class="net.sf.ehcache.Cache"
                   init-method="initialise"
                   destroy-method="dispose">
                     <b:constructor-arg value="casTickets"/>
                     <b:constructor-arg value="50"/>
                     <b:constructor-arg value="true"/>
                     <b:constructor-arg value="false"/>
                     <b:constructor-arg value="3600"/>
                     <b:constructor-arg value="900"/>
                 </b:bean>
             </b:property>
         </b:bean>
     </b:property>
 </b:bean>
 

Field Summary

static String	CAS_STATEFUL_IDENTIFIER Used to identify a CAS request for a stateful user agent, such as a web browser.
static String	CAS_STATELESS_IDENTIFIER Used to identify a CAS request for a stateless user agent, such as a remoting protocol client (e.g.

Fields inherited from class org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter

authenticationDetailsSource, eventPublisher, messages, SPRING_SECURITY_LAST_EXCEPTION_KEY

Fields inherited from class org.springframework.web.filter.GenericFilterBean

logger

Constructor Summary

CasAuthenticationFilter()

Method Summary

Authentication	attemptAuthentication(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Performs actual authentication.
protected String	obtainArtifact(javax.servlet.http.HttpServletRequest request) If present, gets the artifact (CAS ticket) from the HttpServletRequest.
protected boolean	requiresAuthentication(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Overridden to provide proxying capabilities.
void	setAuthenticationFailureHandler(AuthenticationFailureHandler failureHandler) Wraps the AuthenticationFailureHandler to distinguish between handling proxy ticket authentication failures and service ticket failures.
void	setProxyAuthenticationFailureHandler(AuthenticationFailureHandler proxyFailureHandler) Sets the AuthenticationFailureHandler for proxy requests.
void	setProxyGrantingTicketStorage(org.jasig.cas.client.proxy.ProxyGrantingTicketStorage proxyGrantingTicketStorage)
void	setProxyReceptorUrl(String proxyReceptorUrl)
void	setServiceProperties(ServiceProperties serviceProperties)
protected void	successfulAuthentication(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, javax.servlet.FilterChain chain, Authentication authResult) Default behaviour for successful authentication.

Methods inherited from class org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter

afterPropertiesSet, doFilter, getAllowSessionCreation, getAuthenticationManager, getFailureHandler, getFilterProcessesUrl, getRememberMeServices, getSuccessHandler, setAllowSessionCreation, setApplicationEventPublisher, setAuthenticationDetailsSource, setAuthenticationManager, setAuthenticationSuccessHandler, setContinueChainBeforeSuccessfulAuthentication, setFilterProcessesUrl, setMessageSource, setRememberMeServices, setRequiresAuthenticationRequestMatcher, setSessionAuthenticationStrategy, successfulAuthentication, unsuccessfulAuthentication

Methods inherited from class org.springframework.web.filter.GenericFilterBean

addRequiredProperty, destroy, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, initFilterBean, setBeanName, setEnvironment, setServletContext

Methods inherited from class java.lang.Object

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

Field Detail

CAS_STATEFUL_IDENTIFIER

public static final String CAS_STATEFUL_IDENTIFIER

Used to identify a CAS request for a stateful user agent, such as a web browser.

See Also:

Constant Field Values

CAS_STATELESS_IDENTIFIER

public static final String CAS_STATELESS_IDENTIFIER

Used to identify a CAS request for a stateless user agent, such as a remoting protocol client (e.g. Hessian, Burlap, SOAP etc). Results in a more aggressive caching strategy being used, as the absence of a HttpSession will result in a new authentication attempt on every request.

See Also:

Constant Field Values

Constructor Detail

CasAuthenticationFilter

public CasAuthenticationFilter()

Method Detail

successfulAuthentication

protected final void successfulAuthentication(javax.servlet.http.HttpServletRequest request,
                                              javax.servlet.http.HttpServletResponse response,
                                              javax.servlet.FilterChain chain,
                                              Authentication authResult)
                                       throws IOException,
                                              javax.servlet.ServletException

Description copied from class: AbstractAuthenticationProcessingFilter

Default behaviour for successful authentication.

1. Sets the successful Authentication object on the SecurityContextHolder
2. Informs the configured RememberMeServices of the successful login
3. Fires an InteractiveAuthenticationSuccessEvent via the configured ApplicationEventPublisher
4. Delegates additional behaviour to the AuthenticationSuccessHandler.

Subclasses can override this method to continue the FilterChain after successful authentication.

Overrides:

successfulAuthentication in class AbstractAuthenticationProcessingFilter

authResult - the object returned from the attemptAuthentication method.

Throws:

IOException

javax.servlet.ServletException

attemptAuthentication

public Authentication attemptAuthentication(javax.servlet.http.HttpServletRequest request,
                                            javax.servlet.http.HttpServletResponse response)
                                     throws AuthenticationException,
                                            IOException

Description copied from class: AbstractAuthenticationProcessingFilter

Performs actual authentication.

The implementation should do one of the following:

1. Return a populated authentication token for the authenticated user, indicating successful authentication
2. Return null, indicating that the authentication process is still in progress. Before returning, the implementation should perform any additional work required to complete the process.
3. Throw an AuthenticationException if the authentication process fails

Specified by:

attemptAuthentication in class AbstractAuthenticationProcessingFilter

Parameters:

request - from which to extract parameters and perform the authentication

response - the response, which may be needed if the implementation has to do a redirect as part of a multi-stage authentication process (such as OpenID).

Returns:

the authenticated user token, or null if authentication is incomplete.

Throws:

AuthenticationException - if authentication fails.

IOException

obtainArtifact

protected String obtainArtifact(javax.servlet.http.HttpServletRequest request)

If present, gets the artifact (CAS ticket) from the HttpServletRequest.

Parameters:

request -

Returns:

if present the artifact from the HttpServletRequest, else null

requiresAuthentication

protected boolean requiresAuthentication(javax.servlet.http.HttpServletRequest request,
                                         javax.servlet.http.HttpServletResponse response)

Overridden to provide proxying capabilities.

Overrides:

requiresAuthentication in class AbstractAuthenticationProcessingFilter

Returns:

true if the filter should attempt authentication, false otherwise.

setProxyAuthenticationFailureHandler

public final void setProxyAuthenticationFailureHandler(AuthenticationFailureHandler proxyFailureHandler)

Sets the AuthenticationFailureHandler for proxy requests.

Parameters:

proxyFailureHandler -

setAuthenticationFailureHandler

public final void setAuthenticationFailureHandler(AuthenticationFailureHandler failureHandler)

Wraps the AuthenticationFailureHandler to distinguish between handling proxy ticket authentication failures and service ticket failures.

Overrides:

setAuthenticationFailureHandler in class AbstractAuthenticationProcessingFilter

setProxyReceptorUrl

public final void setProxyReceptorUrl(String proxyReceptorUrl)

setProxyGrantingTicketStorage

public final void setProxyGrantingTicketStorage(org.jasig.cas.client.proxy.ProxyGrantingTicketStorage proxyGrantingTicketStorage)

setServiceProperties

public final void setServiceProperties(ServiceProperties serviceProperties)