Question

I’m attempting to login to a cPanel using a POST Request in VB.Net. I have the correct credentials when logging in and when posting I still get an ‘Unauthorized (401)’ response when it should be ‘301’ (analysed using Tamper Data Firefox Add-On). Below is my post request information and function.

  Private Function POSTreq(ByVal URL$, ByVal Data$)
        Dim tempCookie As New CookieContainer
        Dim DataBytes As Byte() = Encoding.ASCII.GetBytes(Data)
        Dim Request As HttpWebRequest = TryCast(WebRequest.Create(URL), HttpWebRequest)
        Request.Method = "POST"
        Request.ContentType = "application/x-www-form-urlencoded"
        Request.ContentLength = DataBytes.Length

        Dim PostData As Stream = Request.GetRequestStream()
        PostData.Write(DataBytes, 0, DataBytes.Length)
        PostData.Close()

        Dim Response As HttpWebResponse = Request.GetResponse()
        Dim ResponseStream As Stream = Response.GetResponseStream()
        Dim StreamReader As New StreamReader(ResponseStream)
        Dim Text$ = StreamReader.ReadToEnd()

        Return Text
    End Function

Post URL

http://example.com:2082/login/

Post Data

login_theme=cpanel&user=USERNAME&pass=PASSWORD&goto_uri=%2F

Answer 1

I could reproduce your described behaviour with your code.

If I set the CookieContainer it works on my side, and I was able to log in:

rem ...
Request.CookieContainer = tempCookie
Request.Method = "POST"
rem ... and so on ...

The second Solution would be to just provide the Credentials:

rem ...
Dim myFullUri = new Uri(URL)
Dim myCredentials As New NetworkCredential(Username, Password)
Dim myCache As New CredentialCache()

rem Add the credentials for that specific host and 
rem for "Basic" authentication only
myCache.Add(New Uri(myFullUri.Scheme & "://" & myFullUri.Authority), _
    "Basic", myCredentials)

Request.Credentials = myCache

Request.CookieContainer = tempCookie
Request.Method = "POST"
rem ... and so on ...