Curious Case of Windows Forms Authentication via PowerShell

Welcome Forums General PowerShell Q&A Curious Case of Windows Forms Authentication via PowerShell

This topic contains 0 replies, has 1 voice, and was last updated by  Forums Archives 7 years ago.

  • Author
  • #5402

    Points: 0
    Rank: Member

    by karmista at 2013-01-05 06:01:49

    Curious Case of Windows Forms Authentication via PowerShell –
    How to login to a webpage via powershell and download a million pdf documents?

    Hi Powershell Gurus,

    Need your assistance with this interesting problem in this regard.
    We need to login to a webpage via powershell and download nearly a million pdf documents. There are 2 levels of authentication – Negotiate (via a standard pop-up & Forms (via the UN/Pwd field in the login.aspx)

    Last week, I had a post on this wonderful forum & got a brilliant idea to pursue a programmatic approach.

    The web site is hosted on IIS 6. It has "Integrated Windows Authentication" check box checked (IIS 6).

    web.config Authentication & Authorization info looks like this –



    Below Power Shell code authenticates & gets to the login.aspx page. However, I am unable to perform the "Forms" authentication from the login.aspx page.

    If I attempt to directly download URL2 i.e. $webclient.DownloadFile($url2,$path), I get a HTTP 500 Internal Server Error message.

    Need your assistance in getting through these authentication via tweaks to the below code.

    $url = ""
    $path = "D:\temp\myfile1.pdf"

    #$url2 = ""

    $webclient = new-object System.Net.WebClient
    $credCache = new-object System.Net.CredentialCache

    $creds = new-object System.Net.NetworkCredential("username","password", "domain")
    $credCache.Add($url, "Negotiate", $creds)
    $webclient.Credentials = $credCache


    by DonJ at 2013-01-08 08:23:57

    This is going to be pretty complicated, and you're getting pretty deep into .NET programming. For a PowerShell forum, I don't think you're necessarily going to get a lot of answers. You might consider asking at, which has a developer following and folks who've probably done this.

    Forms authentication doesn't accept a credential in the way you're providing. With Forms auth, you're not responding to an HTTP authentication prompt, you're entering a username and password into form fields and pressing a Submit button. The Web server authenticates that on the back-end, and then issues you one or more cookies in the response to show you've been authenticated. You have to store those cookies and re-present them in every new request. A Web browser does all of this for you; given that you're essentially writing you're own Web browser, it's on you.

    I can't help but wonder if some Download Manager-style browser plugin might not be a better way for you to do this. I've seen tools that can crawl a site and download files in bulk. Otherwise, you're going to be doing quite a lot of coding to make this work.

The topic ‘Curious Case of Windows Forms Authentication via PowerShell’ is closed to new replies.