1. Introduction to the Spring Security CAS Plugin

The CAS plugin adds CAS single sign-on support to a Grails application that uses Spring Security. It depends on the Spring Security Core plugin.

Once you have configured a CAS server and have configured your Grails application(s) as clients, you can authenticate to any application that is a client of the CAS server and be automatically authenticated to all other clients.

2. Usage

Configuring your CAS server is beyond the scope of this document. There are many different approaches and this will most likely be done by IT staff. It’s assumed here that you already have a running CAS server.

CAS is a popular single sign-on implementation. It’s open source and has an Apache-like license, and is easy to get started with but is also highly configurable. In addition it has clients written in Java, .Net, PHP, Perl, and other languages.

2.1. Installation

There isn’t much that you need to do in your application to be a CAS client. Add a dependency in build.gradle for this plugin:

If you are using 3.3.x use:

build.gradle
dependencies {
   ...
   compile 'org.grails.plugins:spring-security-cas:3.1.1.BUILD-SNAPSHOT'
   ...

If you are using Grails 3.0.x 3.1.x or 3.2.x use:

build.gradle
dependencies {
   ...
   compile 'org.grails.plugins:spring-security-cas:3.0.1'
   ...

then configure any required parameters and whatever optional parameters you want in application.yml or application.groovy. These are described in detail in the Configuration section but typically you only need to set these properties:

grails-app/conf/application.yml
grails:
    plugin:
        springsecurity:
            cas:
                loginUri: /login
                serviceUrl: http://localhost:8080/login/cas
                serverUrlPrefix: https://your-cas-server/cas
                proxyCallbackUrl: http://localhost:8080/secure/receptor
                proxyReceptorUrl: /secure/receptor

2.2. Single Signout

Single signout is enabled by default and enables signing out for all CAS-managed applications with one logout. This works best in the plugin when combined with the afterLogoutUrl parameter, for example:

grails:
   plugin:
      springsecurity:
         logout:
            afterLogoutUrl: https://your-cas-server/cas/logout?url=http://localhost:8080/

With this configuration, when a user logs out locally by navigating to /logout/ they’ll then be redirected to the CAS server’s logout URL. This request includes a local URL to redirect back afterwards. When the whole process is finished they’ll be logged out locally and at the CAS server, so subsequent secure URLs at the local server or other CAS-managed servers will require a new login.

If you don’t want the single signout filter registered, you can disable the feature:

grails:
   plugin:
      springsecurity:
         cas:
            useSingleSignout: false

3. Configuration

There are a few configuration options for the CAS plugin.

All of these property overrides must be specified in grails-app/conf/application.yml (or application.groovy) using the grails.plugin.springsecurity suffix, for example

grails:
   plugin:
      springsecurity:
         cas:
            serverUrlPrefix: https://cas-server/cas
Name Default Meaning

cas.active

true

whether the plugin is enabled (e.g. to disable per-environment)

cas.serverUrlPrefix

null, must be set

the 'root' of all CAS server URLs, e.g. https://cas-server/cas

cas.serverUrlEncoding

'UTF-8'

encoding for the server URL

cas.loginUri

null, must be set

the login URI, relative to cas.serverUrlPrefix, e.g. /login

cas.sendRenew

false

if true, ticket validation will only succeed if it was issued from a login form, but will fail if it was issued from a single sign-on session. Analogous to IS_AUTHENTICATED_FULLY in Spring Security

cas.serviceUrl

null, must be set

the local application login URL, e.g. http://localhost:8080/login/cas

cas.key

'grails-spring-security-cas', should be changed

used by CasAuthenticationProvider to identify tokens it previously authenticated

cas.artifactParameter

'ticket'

the ticket login url parameter

cas.serviceParameter

'service'

the service login url parameter

cas.filterProcessesUrl

'/login/cas'

the URL that the filter intercepts for login

cas.proxyCallbackUrl

null, should be set

proxy callback url, e.g. 'http://localhost:8080/secure/receptor'

cas.proxyReceptorUrl

null, should be set

proxy receptor url, e.g. '/secure/receptor'

cas.useSingleSignout

true

if true a org.jasig.cas.client.session. SingleSignOutFilter is registered

4. Release History

  • Version 3.1.0

    • released Oct 3, 2017

  • Version 2.0.1

    • released Oct 3, 2017

  • Version 3.0.1

    • released May 2, 2017

  • Version 3.0.0

    • released December 8, 2015

  • Version 2.0.0

    • released December 7, 2015

  • Version 3.0.0.M1

    • released September 23, 2015

  • Version 2.0-RC1

    • released November 11, 2013

  • Version 1.0.4

    • released July 11, 2012

  • Version 1.0.3

    • released July 4, 2012

  • Version 1.0.2

    • released February 12, 2011

  • Version 1.0.1

    • released September 1, 2010

  • Version 1.0

    • released July 27, 2010

  • Version 0.1

    • released June 18, 2010