For Google, LDAP, or CAS logins

Authorizer is a WordPress plugin that restricts access to a site to specific users, typically students enrolled in a university course. It maintains a list of approved users that you can edit to determine who has access. It also replaces the default WordPress login/authorization system with one relying on an external server, such as Google, CAS, or LDAP. Authorizer lets you limit invalid login attempts to prevent bots from compromising your users’ accounts.