login with VB.NET and httpwebrequest cookiecontainer - vb.net

Question

I think there is a problem with cookiecontainer (httpwebrequest)
there are 2 main functions in my class, first getting a new form (a hidden token in form tag), and it should set the cookies (which not set) and then second function (doLogin) should login the form. why cookie is not set...?
here is my codes: (you can test my code with "http://wetcatdesign.com/wiki/" as wikiURL)
Public Class wiki_submitter
Dim CookieJar As New CookieContainer
Public wikiURL As String
Private Function cutStr(ByVal Str As String, ByVal startStr As String, _
ByVal finishStr As String, Optional ByVal startPos As Integer = 1) As String
Dim start As Integer = InStr(startPos, Str, startStr) + Len(startStr)
Dim finish As Integer = InStr(start + 1, Str, finishStr)
cutStr = Mid(Str, start, finish - start)
End Function
Public Function GetNewForm()
Try
Dim req As HttpWebRequest = HttpWebRequest.Create(wikiURL & "index.php?title=Special:UserLogin&returnto=Main_Page")
Dim res As HttpWebResponse
req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0"
res = req.GetResponse()
'Setting cookies
req.CookieContainer = CookieJar
'getting HTML result
Dim sr As StreamReader = New StreamReader(res.GetResponseStream())
Dim HTML = sr.ReadToEnd
sr.Close()
Dim wpLoginToken As String = cutStr(HTML, "<input type=""hidden"" name=""wpLoginToken"" value=""", """") ' finding wpLoginToken parameter
GetNewForm = wpLoginToken
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Function
Public Function doLogin(ByVal username As String, ByVal pass As String)
Dim req As HttpWebRequest = HttpWebRequest.Create(wikiURL & "index.php?title=Special:UserLogin&action=submitlogin&type=login")
Dim res As HttpWebResponse
Dim HTML As String
'-------Setting up headers------------
req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0"
req.Referer = wikiURL & "index.php?title=Special:UserLogin&returnto=Main_Page"
req.ContentType = "application/x-www-form-urlencoded" 'Form content type
req.Method = "POST" 'data will be send in POST method
req.CookieContainer = CookieJar 'Setting cookies
'-------------------------------------
Dim sw As StreamWriter = New StreamWriter(req.GetRequestStream)
Dim poststring = "wpLoginToken=" & GetNewForm() & "&wpLoginattempt=Log in&wpName=" & username & "&wpPassword=" & pass
Try
sw.Write(poststring)
Catch ex As Exception
MsgBox(ex.Message)
Finally
sw.Close()
End Try
res = req.GetResponse()
Dim sr As StreamReader = New StreamReader(res.GetResponseStream())
HTML = sr.ReadToEnd 'HTML as result
sr.Close()
doLogin = HTML 'returns HTML result
End Function
End Class

Answer 1

What happens if you set it before res = req.GetResponse() ?

Answer 2

Firstly, you need to set cookies before sending the request and secondly you need to extract cookies from the response when you expect them. Here's one way of doing it
Public Class wiki_submitter
Dim CookieJar As New CookieContainer
Public wikiURL As String
Private Function cutStr(ByVal Str As String, ByVal startStr As String, _
ByVal finishStr As String, Optional ByVal startPos As Integer = 1) As String
Dim start As Integer = InStr(startPos, Str, startStr) + Len(startStr)
Dim finish As Integer = InStr(start + 1, Str, finishStr)
cutStr = Mid(Str, start, finish - start)
End Function
Public Function GetNewForm()
Try
Dim req As HttpWebRequest = HttpWebRequest.Create(wikiURL & "index.php?title=Special:UserLogin&returnto=Main_Page")
Dim res As HttpWebResponse
req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0"
res = req.GetResponse()
'Setting cookies
'req.CookieContainer = CookieJar
SaveIncomingCookies(res, wikiURL)
'getting HTML result
Dim sr As StreamReader = New StreamReader(res.GetResponseStream())
Dim HTML = sr.ReadToEnd
sr.Close()
Dim wpLoginToken As String = cutStr(HTML, "<input type=""hidden"" name=""wpLoginToken"" value=""", """") ' finding wpLoginToken parameter
GetNewForm = wpLoginToken
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Function
Public Function doLogin(ByVal username As String, ByVal pass As String)
Dim req As HttpWebRequest = HttpWebRequest.Create(wikiURL & "index.php?title=Special:UserLogin&action=submitlogin&type=login")
Dim res As HttpWebResponse
Dim HTML As String
'-------Setting up headers------------
req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0"
req.Referer = wikiURL & "index.php?title=Special:UserLogin&returnto=Main_Page"
req.ContentType = "application/x-www-form-urlencoded" 'Form content type
req.Method = "POST" 'data will be send in POST method
'req.CookieContainer = CookieJar 'Setting cookies
'-------------------------------------
Dim sw As StreamWriter = New StreamWriter(req.GetRequestStream)
Dim poststring = "wpLoginToken=" & GetNewForm() & "&wpLoginattempt=Log in&wpName=" & username & "&wpPassword=" & pass
Try
req.CookieContainer = CookieJar
sw.Write(poststring)
Catch ex As Exception
MsgBox(ex.Message)
Finally
sw.Close()
End Try
res = req.GetResponse()
SaveIncomingCookies(res, wikiURL)
Dim sr As StreamReader = New StreamReader(res.GetResponseStream())
HTML = sr.ReadToEnd 'HTML as result
sr.Close()
doLogin = HTML 'returns HTML result
End Function
Private Function SaveIncomingCookies(ByRef response As HttpWebResponse, ByRef Uri As String)
If response.Headers("Set-Cookie") <> Nothing Then
CookieJar.SetCookies(New Uri("http://wetcatdesign.com"), response.Headers("Set-Cookie"))
End If
End Function
End Class