How to impersonate a user for a short period to access a page/file?
<p>I'm using FormsAuthentication to allow users to login. However I have a Excel file that gets generated in memory by one of my pages, for example when they go to:</p>

<p><a href="http://www.mywebsite.com/report?date=050809" rel="nofollow">http://www.mywebsite.com/report?date=050809</a></p>

<p>This generates an Excel report for that date given, in a memory stream and passes it back to the user to download as long as they are logged in. But what I need to do is allow them to access that URL and the Excel report from that link, without having to login manually, is there a quick and dirty way to login them in (impersonate?) for a very short period to get the file and then expire their cookie after a few seconds?</p>

<p>(I'm doing this through asp.net mvc by the way, but it should make no difference I assume in webforms either)</p>
