title: Windows Authentication Between React and ASP.NET Back-end
body: <p>I have a multi-tier application which is using 2 NET Core ASP.NET tiers.</p>
  
  <ul>
  <li>Tier 01
  
  <ul>
  <li>React JS hosted via ASP.NET Core</li>
  </ul></li>
  <li>Tier 02
  
  <ul>
  <li>Back-end HTTP rest</li>
  </ul></li>
  </ul>
  
  <p>The Tier 01 is using NTLM, so when the User open the Browser, ASP.NET Core loads the React SPA and from ASP.NET Core I can get the IPrincipal of the current Windows User. The Back-end, unfortunately, is always running in the context of the App Pool service account.</p>
  
  <p>In this scenario, what would be the correct way, from React, to call the Back-end using the Windows Account which is running the application? Is there a way to generate a Token, like OAuth, in the Front-end NET Core host and then pass it to the Back-end?</p>
  
  <p><strong>Note</strong></p>
  
  <p>I do have an architectural requirement, I can't use Username and Password, I can't use Basic Authentication. The Front-end must open using NTLM and display the current Windows Account (<em>this part is working</em>)</p>