1--- 2stage: Ecosystem 3group: Integrations 4info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments 5--- 6 7# CAS OmniAuth Provider **(FREE SELF)** 8 9To enable the CAS OmniAuth provider you must register your application with your 10CAS instance. This requires the service URL GitLab supplies to CAS. It should be 11something like: `https://gitlab.example.com:443/users/auth/cas3/callback?url`. 12Handling for Single Logout (SLO) is enabled by default, so you only have to 13configure CAS for back-channel logout. 14 151. On your GitLab server, open the configuration file. 16 17 For Omnibus package: 18 19 ```shell 20 sudo editor /etc/gitlab/gitlab.rb 21 ``` 22 23 For installations from source: 24 25 ```shell 26 cd /home/git/gitlab 27 28 sudo -u git -H editor config/gitlab.yml 29 ``` 30 311. See [Configure initial settings](omniauth.md#configure-initial-settings) for initial settings. 32 331. Add the provider configuration: 34 35 For Omnibus package: 36 37 ```ruby 38 gitlab_rails['omniauth_providers'] = [ 39 { 40 name: "cas3", 41 label: "Provider name", # optional label for login button, defaults to "Cas3" 42 args: { 43 url: "CAS_SERVER", 44 login_url: "/CAS_PATH/login", 45 service_validate_url: "/CAS_PATH/p3/serviceValidate", 46 logout_url: "/CAS_PATH/logout" 47 } 48 } 49 ] 50 ``` 51 52 For installations from source: 53 54 ```yaml 55 - { name: 'cas3', 56 label: 'Provider name', # optional label for login button, defaults to "Cas3" 57 args: { 58 url: 'CAS_SERVER', 59 login_url: '/CAS_PATH/login', 60 service_validate_url: '/CAS_PATH/p3/serviceValidate', 61 logout_url: '/CAS_PATH/logout' } } 62 ``` 63 641. Change 'CAS_PATH' to the root of your CAS instance (such as `cas`). 65 661. If your CAS instance does not use default TGC lifetimes, update the `cas3.session_duration` to at least the current TGC maximum lifetime. To explicitly disable SLO, regardless of CAS settings, set this to 0. 67 681. Save the configuration file. 69 701. [Reconfigure](../administration/restart_gitlab.md#omnibus-gitlab-reconfigure) or 71 [restart GitLab](../administration/restart_gitlab.md#installations-from-source) for the changes to 72 take effect if you installed GitLab via Omnibus or from source respectively. 73 74On the sign in page there should now be a CAS tab in the sign in form. 75