title: How to get access token from httpcontext using owin and Mvc 5
body: <p>I've got a IDP implemented in <a href="https://identityserver4.readthedocs.io/en/release/" rel="noreferrer">IdentityServer 4</a>. My web app client(implemented in Mvc 5) authenticates with the IDP but now I need to get the access token from the request.
  A way to do that in .Net Core is to use the <a href="https://docs.microsoft.com/en-us/aspnet/core/api/microsoft.aspnetcore.authentication.authenticationtokenextensions" rel="noreferrer"><code>Microsoft.AspNetCore.Authentication.AuthenticationTokenExtensions</code></a> like so:</p>
  
  <pre><code>HttpContext.Authentication.GetTokenAsync("acccess_token")
  </code></pre>
  
  <p>I would like to be able to do the same in my .net Mvc5 web app client but I can't find any nuget package or namespace that has a similar implementation. It is important to be able to do this in MVC5 and not .net Core. Anyone came across this before?</p>
  
  <p>PS- Also worth to mention that I'm using OpenIdConnect</p>