Imports System.Net
.
.
.
Public Sub WriteXMLData(URL as String, UserId as String, Password as String)
    Dim oXML As New System.Xml.XmlDocument
    Dim oRequest As New HTTPWeb.Request
    Dim oNode As System.Xml.XmlNode
    Dim oRootNode As System.Xml.XmlNode
    Dim sRawXML As String

    Try
        sRawXML = ReadURL(sURL, sSiteLogin, sSitePwd, "")
        oXML.LoadXml(sRawXML)     ' This will generate an error if the Raw XML is malformed
        oRootNode = oXML.ChildNodes(0)

        Response.Write("Root node name is [" & oRootNode.Name & "]") 
        For Each oNode In oRootNode
            Response.Write("Found Child node [" & oNode.Name & "]")
            ' Etc.
        Next
    Catch ex as System.Exception
        Response.Write("<p>Your URL is junk, dude!")
    End Try
End Sub

Private Function ReadURL(ByVal URL As String, ByVal UserId As String, ByVal Password As String, ByVal Domain As String) As String
    Dim oRequest As New HTTPWeb.Request

    ' Create a new request credentials according to the user's input.
    Dim oCred As New NetworkCredential(UserId, Password)
    If Domain = [String].Empty Then
        oCred = New NetworkCredential(UserName, Password)
    Else
        oCred = New NetworkCredential(UserName, Password, Domain)
    End If

    Try
        oRequest.URL = URL
        oRequest.UserId = UserId
        oRequest.Password = Password
        ' You may need to add some credentials here (to do: strip out base from URL passed)
        oRequest.AddCredential("https://www.yourserver.com/", "Negotiate")
        oRequest.AddCredential("https://www.yourserver.com/", "Basic")
        oRequest.AddCredential("https://www.yourserver.com/", "NTLM")
        oRequest.AddCredential("https://www.yourserver.com/", "NTLMSSP")
        oRequest.FormVars.Add("FormVar1", "1")
        oRequest.FormVars.Add("FormVar2", "2")
        oRequest.FormVars.Add("FormVar3", "3")
        oRequest.Execute()
        Return oRequest.Response
    Catch ex As System.Exception
        Return (ex.Message & vbCrLf & ex.StackTrace)
    End Try
End Function

Imports System
Imports System.Net
Imports System.Threading
Imports System.Text
Imports System.IO
Imports System.Collections
Imports System.Collections.Specialized

Namespace HTTPWeb
    Class Request
        Protected allDone As New ManualResetEvent(False)
        Private sResponse As String
        Private sTarget As String
        Private sPostData As String
        Private oFormVars As System.Collections.Hashtable
        Private sUserId As String
        Private sPassword As String
        Private sDomain As String
        Private sCredentials As System.Collections.ArrayList
        Private oCredentialCache As CredentialCache

        Public Sub New()
            oFormVars = New System.Collections.Hashtable
            sTarget = ""
            sPostData = ""
            sResponse = ""
            sUserId = ""
            sPassword = ""
            sDomain = ""
            sCredentials = New System.Collections.ArrayList
            oCredentialCache = Nothing
        End Sub

        Public Sub AddCredential(ByVal Site As String, ByVal Type As String)
            Dim sItem(1, 2) As String
            sItem(0, 0) = Site
            sItem(0, 1) = Type
            sCredentials.Add(sItem)
        End Sub

        Public Property CredentialCache() As CredentialCache
            Get
                Return oCredentialCache
            End Get
            Set(ByVal Value As CredentialCache)
                oCredentialCache = Value
            End Set
        End Property

        Public Property UserId() As String
            Get
                Return (sUserId)
            End Get
            Set(ByVal Value As String)
                sUserId = Value
            End Set
        End Property

        Public Property Password() As String
            Get
                Return ("**********")
            End Get
            Set(ByVal Value As String)
                sPassword = Value
            End Set
        End Property

        Public Property Domain() As String
            Get
                Return sDomain
            End Get
            Set(ByVal Value As String)
                sDomain = Value
            End Set
        End Property

        Property URL() As String
            Get
                Return sTarget
            End Get
            Set(ByVal Value As String)
                sTarget = Value
            End Set
        End Property

        ReadOnly Property FormVars() As System.Collections.Hashtable
            Get
                Return oFormVars
            End Get
        End Property

        ReadOnly Property Response() As String
            Get
                Return (sResponse)
            End Get
        End Property

        Public Sub Execute()
            ' Create a new HttpWebRequest object.
            Dim oRequest As HttpWebRequest = CType(WebRequest.Create(sTarget), HttpWebRequest)

            ' Assign an instance of a System.Net.ICertificatePolicy  for this application
            '   this is required to bypass the default return value for CheckValidationResult
            '   which is 'false'. This overrides the default behavior which causes all HTTPS over SSL 
            '   to fail
            ServicePointManager.CertificatePolicy = New ERSCertificateValidation

            ' Set the ContentType property.
            oRequest.ContentType = "application/x-www-form-urlencoded"

            '  Set the Method property to 'POST' to post data to the URI.
            oRequest.Method = "POST"

            ' Create the Credential Cache Object if user has not already
            If oCredentialCache Is Nothing Then
                oCredentialCache = New CredentialCache
                If sCredentials.Count > 0 Then
                    Dim oNetworkCredential As New NetworkCredential(sUserId, sPassword)
                    Dim sItem(,) As String
                    For Each sItem In sCredentials
                        oCredentialCache.Add(New Uri(sItem(0, 0).ToString), sItem(0, 1).ToString, oNetworkCredential)
                    Next
                End If
            End If
            oRequest.Credentials = oCredentialCache

            ' Force http request to authenticate if the userid is specified
            oRequest.PreAuthenticate = (sUserId.Length > 0)

            ' Start the asynchronous operation.        
            Dim oResult As IAsyncResult = CType(oRequest.BeginGetRequestStream(AddressOf ReadCallback, oRequest), IAsyncResult)

            ' Keep the main thread from continuing while the asynchronous operation completes. 
            ' A real world application could do something useful such as updating its user interface. 
            allDone.WaitOne()

            '  Get the response.
            Dim response As HttpWebResponse = CType(oRequest.GetResponse(), HttpWebResponse)

            Try
                response = CType(oRequest.GetResponse(), HttpWebResponse)
            Catch ex As System.Exception
                Me.sResponse = "<br>Error while getting response"
                Exit Sub
            End Try

            Dim streamResponse As Stream = response.GetResponseStream()
            Dim streamRead As New StreamReader(streamResponse)
            sResponse = streamRead.ReadToEnd()

            ' Close Stream object.
            streamResponse.Close()
            streamRead.Close()

            ' Release the HttpWebResponse.
            response.Close()

        End Sub ' Execute()

        Private Sub ReadCallback(ByVal asynchronousResult As IAsyncResult)
            Dim request As HttpWebRequest = CType(asynchronousResult.AsyncState, HttpWebRequest)
            ' End the operation.
            Dim postStream As Stream = request.EndGetRequestStream(asynchronousResult)
            Dim oEntry As System.Collections.DictionaryEntry
            Dim sPostData As String

            If oFormVars.Count > 0 Then
                For Each oEntry In oFormVars
                    sPostData &= "&" & oEntry.Key & "=" & oEntry.Value.ToString
                Next
                sPostData = sPostData.Substring(1)

                '  Convert the string into byte array.
                Dim byteArray As Byte() = Encoding.UTF8.GetBytes(sPostData)
                ' Write to the stream.
                postStream.Write(byteArray, 0, sPostData.Length)
                postStream.Close()
            End If
            allDone.Set()
        End Sub ' ReadCallback()

    End Class

    Public Class CertificateValidation
        Implements System.Net.ICertificatePolicy

        Public Function CheckValidationResult(ByVal sp As ServicePoint, ByVal cert As System.Security.Cryptography.X509Certificates.X509Certificate, ByVal req As WebRequest, ByVal problem As Integer) As Boolean Implements System.Net.ICertificatePolicy.CheckValidationResult
            Return True
        End Function
    End Class

End Namespace