Server Form Post

P

pinster

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Joined
Jan 28, 2002
Messages
29
Location
Penang, Malaysia
Hi, I remember the old days, we can do form posting using INET or Winsock. Switching to ASP.NET, the server-side form is working in a different way... eg. post back, view state, etc.

I'm trying to programatically login to the website, http://mawar.www.gov.my/eGA.NET/aca.aspx?Target=UserMain&LANG=1

but I'm not getting the desire result page although i had submitted the correct username and password...

My code goes like this: (It's a custom control which is used in a web form)
Visual Basic: 
        Dim _ResponseData As String, _ViewState As String
        Dim _FormParam As String, oWebRequest As HttpWebRequest, oWebResponse As HttpWebResponse
        Dim ResponseReader As StreamReader, RequestWriter As StreamWriter
        Dim cookies As New CookieContainer, _target As String
        Dim _EventTarget As String, _EventArg As String

        'Download HTML
        oWebRequest = HttpWebRequest.Create("http://mawar.www.gov.my/eGA.NET/aca.aspx?Target=UserMain&LANG=1")
        ResponseReader = New StreamReader(oWebRequest.GetResponse.GetResponseStream)
        _ResponseData = ResponseReader.ReadToEnd
        ResponseReader.Close()

        'Extract ViewState
        _ResponseData = _ResponseData.Replace("name=""__VIEWSTATE"" value=""", "~")

        '_ViewState = _ResponseData.Substring(_ResponseData.IndexOf("~") + 1, (_ResponseData.IndexOf(""" />", _ResponseData.IndexOf("~")) - 1) - _ResponseData.IndexOf("~"))
        _ViewState = Web.HttpUtility.UrlEncodeUnicode(_ResponseData.Substring(_ResponseData.IndexOf("~") + 1, (_ResponseData.IndexOf(""" />", _ResponseData.IndexOf("~")) - 1) - _ResponseData.IndexOf("~")))

        _target = "Login"
        _EventTarget = ""
        _EventArg = ""
        _FormParam = String.Format("target={0}&__EVENTTARGET={1}&__EVENTARGUMENT={2}&__VIEWSTATE={3}&txtUser={4}&txtPassword={5}", _target, _EventTarget, _EventArg, _ViewState, "user", "pwd")

        oWebRequest = HttpWebRequest.Create("http://mawar.www.gov.my/eGA.NET/aca.aspx?target=Login&p=http://mawar.www.gov.my/eGA.NET/aca.aspx?target=UserMain")
        oWebRequest.Method = "POST"
        oWebRequest.ContentType = "application/x-www-form-urlencoded"
        oWebRequest.ContentLength = _FormParam.Length
        'oWebRequest.CookieContainer = cookies

        RequestWriter = New StreamWriter(oWebRequest.GetRequestStream)
        RequestWriter.Write(_FormParam)
        RequestWriter.Close()

        'oWebRequest.GetResponse.Close()

        oWebResponse = oWebRequest.GetResponse 'HttpWebRequest.Create("http://mawar.www.gov.my/eGA.NET/aca.aspx?Target=UserMain&LANG=1")
        'oWebRequest.CookieContainer = cookies
        ResponseReader = New StreamReader(oWebResponse.GetResponseStream)
        _text = ResponseReader.ReadToEnd
        ResponseReader.Close()

Basically, I'm requesting for the login.aspx, get the viewstate, post my username and password, then get the protected page. In this example, if it's login failed, we should get back to the same login page with an error message 'Invalid Login. Please enter a valid User Name and Password'. Otherwise, if successful, we should get to another page with the word 'My Profile' inside the page.

I'm really stucked with this.. I hope there is any expert who can help or guide me. Thank you!
 
Have a look at the following code in the Web page:

Code: 
<script language="javascript">
<!--
	function __doPostBack(eventTarget, eventArgument) {
		var theform = document.Form1;
		theform.__EVENTTARGET.value = eventTarget;
		theform.__EVENTARGUMENT.value = eventArgument;
		theform.submit();
	}
// -->
</script>

Perhaps that'll give you a hint as to what you're missing. :)
 
Last time I had to do something similar to you, I just used Mozilla with LiveHTTPHeaders to 1st look at what was sent and receiving, and them perform the same thing in code using HttpRequests/HttpResponse, sort of like what you're doing.
 
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