I've been requested by a client to incorporate OAuth authentication within a REST service. The setup I am working with is client/user accessing a service directly. The service is not connecting to another service. I was asked to have OAuth implemented so that users/clients are authenticated by supplying the username and password in the authorization request and not have them log in via a web page. My client has read information from other sites like paypal (https://developer.paypal.com/docs/integration/direct/paypal-oauth2/) which lead him to believe this was possible. So my underlying question is how do I configure an Authoirzation Server to allow for authorization when supplied a password and username directly?
Peter