People reverse engineered\decompiled some code from Sharepoint that happens to have this feature.
I tested it in an ASP.NET MVC 5
app and it's working as expected.
The code is based on decompiling the Microsoft.TeamFoundation.WebAccess which has the "Sign in as a different User" function.
public ActionResult LogOut()
{
HttpCookie cookie = Request.Cookies["TSWA-Last-User"];
if(User.Identity.IsAuthenticated == false || cookie == null || StringComparer.OrdinalIgnoreCase.Equals(User.Identity.Name, cookie.Value))
{
string name = string.Empty;
if(Request.IsAuthenticated)
{
name = User.Identity.Name;
}
cookie = new HttpCookie("TSWA-Last-User", name);
Response.Cookies.Set(cookie);
Response.AppendHeader("Connection", "close");
Response.StatusCode = 401; // Unauthorized;
Response.Clear();
//should probably do a redirect here to the unauthorized/failed login page
//if you know how to do this, please tap it on the comments below
Response.Write("Unauthorized. Reload the page to try again...");
Response.End();
return RedirectToAction("Index");
}
cookie = new HttpCookie("TSWA-Last-User", string.Empty)
{
Expires = DateTime.Now.AddYears(-5)
};
Response.Cookies.Set(cookie);
return RedirectToAction("Index");
}
Source:
Force Sign in as a different user while using Windows Authentication in asp.net