Create a Custom Authentication Provider Plug-in

Single sign-on (SSO) lets users access authorized network resources with one login. You validate usernames and passwords against your corporate user database or other client app rather than Salesforce managing separate passwords for each resource. Out of the box, Salesforce supports several external authentication providers for single sign-on, including Facebook, Google, LinkedIn, and service providers that implement the OpenID Connect protocol. By creating a plug-in with Apex, you can add your own OAuth-based authentication provider. Your users can then use the SSO credentials they already use for non-Salesforce applications with your Salesforce orgs.

Before you create your Apex class, you create a custom metadata type record for your authentication provider. For details, see Create a Custom External Authentication Provider.