title: FileServerMiddleware with credentials?
body: <p>We have the requirement in our enterprise environment to serve static file content from a network share in our ASP.NET Core application. Basically, it gets served under some sub path <code>/content</code>. For this, we have the following code, which works fine:</p>
  
  <pre><code>app.UseFileServer(new FileServerOptions
  {
      FileProvider = new PhysicalFileProvider("//our/network/share"),
      RequestPath = new PathString("/content"),
      EnableDirectoryBrowsing = false
  });
  </code></pre>
  
  <p>Now in production the <em>system user</em> under whose context the web application is hosted has no access to the file share. Thus, we have to use a <em>certain technical domain user</em> to access the files and for this we have to provide credentials (username/password) of this system user to the file server. </p>
  
  <p>Unfortunately, we did not find an option to provide credentials to <code>UseFileServer()</code>. Is it anyway possible?</p>