title: ASP.NET authentication to external server with client credentials
body: <p>I have a site (ASP.NET) and this will be an Intranet only site.</p>
  
  <p>Users will connect and be able to upload and edit images and then the image will be saved to a sharepoint Library with their username as the creator. </p>
  
  <p>Right now, it looks like I can't use the user credentials to connect to SharePoint, and it uses the service account, which isn't allowed to the library, and kicks back a 401 error.</p>
  
  <p>Without having to have the user put their credentials on the page, what can I do to authenticate using integrated windows credentials?</p>