title: ASP Core Intercept All Authentication Requests
body: <p><strong>EDIT</strong>
  I'm looking for a generic way to intercept authentication requests, there should be a way to globally configure this, using middle-ware or events etc, unrelated to the framework that I am using(IdentityServer4)</p>
  
  <p>I'm using IdentityServer4 to Authenticate my WebApi.  I'm looking for events to intercept authentication requests post and prior to authentication.</p>
  
  <p>My startup class is configured this way to handle authentication.</p>
  
  <pre><code>app.UseIdentityServerAuthentication(new IdentityServerAuthenticationOptions
  {
      Authority = "http://localhost:5000",
      RequireHttpsMetadata = false,
  
      ApiName = "api1"
  });
  </code></pre>
  
  <p>I'm looking for an event for post authentication, so that I can create a link from IdentityServer4 Users to local users so I can foreign key there references.  </p>
  
  <p>Is there an event or an easy way to plug into Post_Authentication_Requests, and authenication requests in general, I would like to do some additional logging of failed login attempts as well?</p>