GitHub supports a variety of authentication protocols for user management, as described below.
If you accepted the default settings when you configured your GitHub Enterprise instance, you will be using built-in authentication. All authentication details will be stored within your Enterprise instance; users must sign in with a username and password specific to the installation.
To start inviting users to set up their accounts, click Invite user near the bottom of the menu on the left side of the Site Admin dashboard.
Choose a username and provide an email address for each of the user accounts that you'd like to set up. A confirmation email with sign-in instructions will be sent to each of the provided addresses.
If you choose to use LDAP for authentication, GitHub Enterprise can import user account credentials from your LDAP server. You do not need to invite users to your installation—their accounts will be created automatically when they sign in (using their LDAP credentials) for the first time. To view a list of all the LDAP users that GitHub Enterprise was able to find, click LDAP users near the bottom of the menu on the left side of the Site Admin dashboard.
Unlike built-in authentication, CAS doesn't require you to invite users to your GitHub Enterprise instance. Simply send them a link to your instance's sign-in page and they will authenticate through your separate CAS installation.
Unlike built-in authentication, GitHub OAuth doesn't require you to invite users to your GitHub Enterprise instance. Simply send them a link to your instance's sign-in page and they will authenticate using their credentials on GitHub.com.