title: Creating a restful Login API
body: <p>I have read a few articles on the subject, but I am just looking for some more advice really.</p>
  
  <p>I have a WordPress site with a login functionality and user database on that site.</p>
  
  <p>What I need to do is allow a 3rd party application to authenticate details which it receives against my WordPress database.</p>
  
  <p>I was thinking the best way to do this would be by sending the data to a REST API, but security wise I cannot think how I can return a successful login without this being easily duplicated by a user.</p>
  
  <p>I have read about oAuth and HMAC, but am not sure which route I should be going down.</p>
  
  <p>Any help greatly appreciated, thanks.</p>
  
  <p>Ian</p>