CAS Single logout not working

Question

I am implementing Single-Sign-On + Single-Log-Out in a Java EE environment through CAS.

On the authentication side I have the cas-server-webapp v4.0.1. Then 2 simple Java + Spring MVC web apps with the cas-client-corev3.1.10.

No issues regarding single sign on. If I access /app1 I'm redirected to cas login page in cas-server-webapp. After the user+pass input I get redirected to /app1 correctly authenticated. In addition, if I navigate to /app2, this one gets its auth ticket. So far so good.

As for single logout, maybe I have misunderstood the doc: but this is what I do:

app1 and app2 have each a Spring controller mapped for /logout url:

@Controller
public class LogoutController {

    @RequestMapping("/logout")
    public String logout(HttpSession session){
        session.invalidate();
        return "redirect:https://cas-server-host:8443/cas/logout?service=http://cas-server-host:9080/cas1/action/index";
    }
}

That is to say, I invalidate the http session and redirect to the cas server logout url so that the tickets get invalidated.

In the cas server log I see that it destroys the TGT ticket and sends a logout request to the CAS filter of each app:

DEBUG [org.jasig.cas.CentralAuthenticationServiceImpl] - <Removing ticket [TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org] from registry.>
DEBUG [org.jasig.cas.ticket.registry.DefaultTicketRegistry] - <Attempting to retrieve ticket [TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org]>
DEBUG [org.jasig.cas.ticket.registry.DefaultTicketRegistry] - <Ticket [TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org] found in registry.>
DEBUG [org.jasig.cas.CentralAuthenticationServiceImpl] - <Ticket found. Processing logout requests and then deleting the ticket...>
DEBUG [org.jasig.cas.logout.SamlCompliantLogoutMessageCreator] - <Generated logout message: [<samlp:LogoutRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" ID="LR-13-TfRj1HnvAjpBjNIdaDvDMJUMXk7wffdXgB5" Version="2.0" IssueInstant="2015-02-10T12:18:18Z"><saml:NameID xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">@NOT_USED@</saml:NameID><samlp:SessionIndex>ST-16-aXpUJpwO4MQ09caXZRKX-cas01.example.org</samlp:SessionIndex></samlp:LogoutRequest>]>
DEBUG [org.jasig.cas.logout.LogoutManagerImpl] - <Sending logout request for: [http://localhost:9080/cas2]>
DEBUG [org.jasig.cas.util.SimpleHttpClient] - <Attempting to access http://localhost:9080/cas2>
DEBUG [org.jasig.cas.logout.SamlCompliantLogoutMessageCreator] - <Generated logout message: [<samlp:LogoutRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" ID="LR-14-BaKvuaIbwxg9Le9H3QIvWORfNSE0dxaxsCE" Version="2.0" IssueInstant="2015-02-10T12:18:20Z"><saml:NameID xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">@NOT_USED@</saml:NameID><samlp:SessionIndex>ST-15-zaX6aojKs0PiggCles6J-cas01.example.org</samlp:SessionIndex></samlp:LogoutRequest>]>
DEBUG [org.jasig.cas.util.SimpleHttpClient] - <Finished sending message to http://localhost:9080/cas2>
DEBUG [org.jasig.cas.logout.LogoutManagerImpl] - <Sending logout request for: [http://localhost:9080/cas1]>
DEBUG [org.jasig.cas.ticket.registry.DefaultTicketRegistry] - <Removing ticket [TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org] from registry>
DEBUG [org.jasig.cas.ticket.registry.DefaultTicketRegistry] - <Attempting to retrieve ticket [TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org]>
DEBUG [org.jasig.cas.util.SimpleHttpClient] - <Attempting to access http://localhost:9080/cas1>
INFO [com.github.inspektr.audit.support.Slf4jLoggingAuditTrailManager] - <Audit trail record BEGIN
=============================================================
WHO: audit:unknown
WHAT: TGT-9-inxrphuRfIFpkbPTvNf6v1bAx7RlR7IMeMUFU0aokNCdbZ43Ij-cas01.example.org
ACTION: TICKET_GRANTING_TICKET_DESTROYED
APPLICATION: CAS
WHEN: Tue Feb 10 12:18:20 CET 2015
CLIENT IP ADDRESS: 192.168.13.164
SERVER IP ADDRESS: 192.168.13.164
=============================================================

Now, suppose that I logged out from /cas1, I am sent back to the cas-server login page. Without login again, if I access /app2, I am allowed to navigated this app as if I were still authenticated and I can access both its java.user.Principal and session. How can this be possible? Shouldn't the logout request received in /app2 have destroyed the Principal and http session?

Answer 1

...my fault, as expected I was missing something. I had to include the Single Sign Out Filter and Listener in both apps :

    <filter>   
        <filter-name>CAS Single Sign Out Filter</filter-name>   
        <filter-class>org.jasig.cas.client.session.SingleSignOutFilter
        </filter-class>
    </filter>
    <filter-mapping>   
        <filter-name>CAS Single Sign Out Filter</filter-name>   
        <url-pattern>/*</url-pattern></filter-mapping>
    <listener>    
        <listener-class>org.jasig.cas.client.session.SingleSignOutHttpSessionListener</listener-class>
    </listener>

    <filter>  
        <filter-name>CAS Authentication Filter</filter-name>  
        <filter-class>org.jasig.cas.client.authentication.AuthenticationFilter</filter-class>  
        <init-param>  
            <param-name>casServerLoginUrl</param-name>  
            <param-value>https://cas-server-host:8443/cas/login</param-value>  
        </init-param>  
        <init-param>  
            <param-name>service</param-name>  
            <param-value>http://localhost:9080/cas1</param-value>  
        </init-param>  
    </filter>
     <filter-mapping>  
        <filter-name>CAS Authentication Filter</filter-name>  
        <url-pattern>/*</url-pattern>  
    </filter-mapping>  

    <filter>  
        <filter-name>CAS Validation Filter</filter-name>  
        <filter-class>org.jasig.cas.client.validation.Cas20ProxyReceivingTicketValidationFilter</filter-class>  
        <init-param>  
            <param-name>casServerUrlPrefix</param-name>  
            <param-value>https://cas-server-host:8443/cas/</param-value>  
        </init-param>  
        <init-param>  
            <param-name>service</param-name>  
            <param-value>http://localhost:9080/cas1</param-value>  
        </init-param>  
    </filter> 
    <filter-mapping>  
        <filter-name>CAS Validation Filter</filter-name>  
        <url-pattern>/*</url-pattern>  
    </filter-mapping>   

    <filter>  
        <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>  
        <filter-class>org.jasig.cas.client.util.HttpServletRequestWrapperFilter</filter-class>  
    </filter>  
    <filter-mapping>  
        <filter-name>CAS HttpServletRequest Wrapper Filter</filter-name>  
        <url-pattern>/*</url-pattern>  
    </filter-mapping>