title: ASP.NET Core 2 Google OAuth token endpoint failure
body: <p>I have a problem that relates to the authentication with the google. 
  I followed the tutorials and finally managed to reach google site where I can select the choose an account section. Then I select one and get redirect to the local address: <a href="https://localhost:44377/signin-google?state" rel="nofollow noreferrer">https://localhost:44377/signin-google?state</a> ...</p>
  
  <p>but there I get:
  An unhandled exception occurred while processing the request.</p>
  
  <pre>
  Exception: OAuth token endpoint failure: Status: Unauthorized;Headers: Cache-Control: max-age=0, private
  Date: Sat, 10 Feb 2018 22:14:21 GMT
  Transfer-Encoding: chunked
  Accept-Ranges: none
  Server: GSE
  Vary: X-Origin, Origin, Accept-Encoding
  WWW-Authenticate: Bearer realm="https://accounts.google.com/"
  X-Content-Type-Options: nosniff
  X-Frame-Options: SAMEORIGIN
  X-XSS-Protection: 1; mode=block
  Alt-Svc: hq=":443"; ma=2592000; quic=51303431; quic=51303339; quic=51303338; quic=51303337; quic=51303335,quic=":443"; ma=2592000; v="41,39,38,37,35"
  ;Body: {
  "error": "invalid_client",
  "error_description": "Unauthorized"
  }
  ;
  
  Microsoft.AspNetCore.Authentication.RemoteAuthenticationHandler+d__12.MoveNext()
  
  </pre>
  
  <p>Any help in investigating this would be very helpful.</p>