surfing with the same CookieContainer

Question

How can you surf on a website assigning the same CookieContainer to each web request?

Answer 1

This is a class I wrote a few years back. It's not quite complete and was done before I fully understood how everything works (It doesn't properly encode complex POST data, for example), but it does work pretty well for the all the flaws and it will demonstrate how you can keep your cookiecontainer. It's also in VB.Net, but you can just build that into a separate assembly or run it through a translator if you need to:

Imports System.Net
Imports System.Collections.Generic

Public Class WebScraper
    Public Sub New()
        SetUserAgent(UserAgent.IE6SP1) ''//default agent
    End Sub

#Region "Cookies"
    Private Cookies As New CookieContainer()

    Public Sub AddCookie(ByVal Name As String, ByVal data As String, Optional ByVal path As String = "", Optional ByVal domain As String = "")
        Dim ck As New Cookie(Name, data, path, domain)
        AddCookie(ck)
    End Sub
    Public Sub AddCookie(ByRef cookie As Cookie)
        Cookies.Add(cookie)
    End Sub

    Public Sub ResetSession()
        Cookies = New CookieContainer()
        ''//TODO: Add other session reset code here
    End Sub

    Public Function GetCookies(ByVal uri As System.Uri) As System.Net.CookieCollection
        Return Cookies.GetCookies(uri)
    End Function
    Public Function GetCookies(ByVal url As String) As Net.CookieCollection
        Dim url2 As Uri = Nothing
        If Uri.TryCreate(url, UriKind.Absolute, url2) Then
            Return Cookies.GetCookies(url2)
        Else
            Return Nothing
        End If
    End Function
#End Region

    Public Property TimeOut() As UInteger
        Get
            Return _TimeOut
        End Get
        Set(ByVal value As UInteger)
            _TimeOut = value
        End Set
    End Property
    Private _TimeOut As UInteger = 100000 ''//100000 matches default used by httprequest if none is specified

    Public Property PageEncoding() As System.Text.Encoding
        Get
            Return _PageEncoding
        End Get
        Set(ByVal value As System.Text.Encoding)
            _PageEncoding = value
        End Set
    End Property
    Private _PageEncoding As System.Text.Encoding = System.Text.Encoding.UTF8

#Region "UserAgents"
    ''// TODO: Update this for FF3, add GoogleBot
    ''// TODO: Move to separate class with distinct sub-types (eg: UserAgents.IE.6XP or UserAgents.FF.2XP, classes that overload .ToString())
    Public Enum UserAgent
        IE6SP1
        IE7_XP
        IE7_Vista
        FF2_XP
        FF2_Vista
        FF2_Mac
        FF2_Linux
        Safari
    End Enum

    Public Sub SetUserAgent(ByVal UserAgent As UserAgent)
        Select Case UserAgent
            Case WebScraper.UserAgent.FF2_Linux
                Agent = "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.4) Gecko/20070713 Firefox/2.0.0.5"
            Case WebScraper.UserAgent.FF2_Mac
                Agent = "Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1) Gecko/20070713 Firefox/2.0.0.5"
            Case WebScraper.UserAgent.FF2_Vista
                Agent = "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.3) Gecko/20070713 Firefox/2.0.0.5"
            Case WebScraper.UserAgent.FF2_XP
                Agent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070713 Firefox/2.0.0.5"
            Case WebScraper.UserAgent.IE6SP1
                Agent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"
            Case WebScraper.UserAgent.IE7_Vista
                Agent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"
            Case WebScraper.UserAgent.IE7_XP
                Agent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)"
            Case WebScraper.UserAgent.Safari
                Agent = "Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en) AppleWebKit/522.12.1 (KHTML, like Gecko) Safari/522.12.1"
        End Select
    End Sub

    Public Sub SetUserAgent(ByVal UserAgent As String)
        Agent = UserAgent
    End Sub

    ''//defaults to IE6 SP1
    ''// TODO: Choose a better default
    Private Agent As String
#End Region

#Region "Get Page"
    Public Function GetPage(ByVal URL As Uri, Optional ByVal PostData As String = "") As String
        Dim reader As IO.StreamReader = Nothing
        Try
            reader = New System.IO.StreamReader(SendRequest(URL, PostData).GetResponseStream, PageEncoding)
            GetPage = reader.ReadToEnd()
        Catch
            GetPage = ""
        Finally
            Try
                reader.Close()
            Catch
            End Try
        End Try
    End Function
    Public Function GetPage(ByVal URL As String, Optional ByVal PostData As String = "") As String
        Dim URL2 As Uri = Nothing
        If Uri.TryCreate(URL, UriKind.Absolute, URL2) Then
            Return GetPage(URL2, PostData)
        Else
            Return ""
        End If
    End Function
    Public Function GetPage(ByVal URL As String, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As String
        Return GetPage(URL, PrepPostData(PostData))
    End Function
    Public Function GetPage(ByVal URL As Uri, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As String
        Return GetPage(URL, PrepPostData(PostData))
    End Function
#End Region

#Region "Get Response"
    Public Function GetResponse(ByVal URL As Uri, Optional ByVal Postdata As String = "") As Object
        Dim x As HttpWebResponse = SendRequest(URL, Postdata)
        If x.ContentType.Contains("text") Then
            Dim result As String
            Dim reader As IO.StreamReader = Nothing
            Try
                reader = New System.IO.StreamReader(x.GetResponseStream, System.Text.Encoding.UTF8) ''// TODO: figure out how to detect actual encoding
                result = reader.ReadToEnd()
            Catch
                result = ""
            Finally
                Try
                    reader.Close()
                Catch
                End Try
            End Try
            Return result
        ElseIf x.ContentType.Contains("image") Then
            Dim result As Drawing.Image
            Try
                result = System.Drawing.Image.FromStream(x.GetResponseStream)
            Catch
                result = Nothing
            End Try
            Return result
        Else
            Return x.GetResponseStream
        End If
    End Function
    Public Function GetResponse(ByVal URL As Uri, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As Object
        Return GetResponse(URL, PrepPostData(PostData))
    End Function
    Public Function GetResponse(ByVal URL As String, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As Object
        Return GetResponse(URL, PrepPostData(PostData))
    End Function
    Public Function GetResponse(ByVal URL As String, Optional ByVal PostData As String = "") As Object
        Dim URL2 As Uri = Nothing
        If Uri.TryCreate(URL, UriKind.Absolute, URL2) Then
            Return GetResponse(URL2, PostData)
        Else
            Return Nothing
        End If
    End Function
#End Region

#Region "SaveResponseToFile"
    Function SaveResponseToFile(ByVal FullFileName As String, ByVal URL As Uri, Optional ByVal PostData As String = "") As Boolean
        Try
            Dim x As New IO.BinaryReader(SendRequest(URL, PostData).GetResponseStream)
            Dim y As New IO.FileStream(FullFileName, IO.FileMode.Create)
            Dim z As New IO.BinaryWriter(y)

            Try ''// TODO: I can do better here
                While True
                    z.Write(x.ReadByte)
                End While
            Catch ''//continue
            End Try

            z.Flush()
            z.Close()
        Catch
            Return False
        End Try
        Return True
    End Function
    Function SaveResponseToFile(ByVal FullFileName As String, ByVal URL As String, Optional ByVal PostData As String = "") As Boolean
        Dim URL2 As Uri = Nothing
        If Uri.TryCreate(URL, UriKind.Absolute, URL2) Then
            Return SaveResponseToFile(FullFileName, URL2, PostData)
        Else : Return False
        End If
    End Function
    Function SaveResponseToFile(ByVal FullFileName As String, ByVal URL As String, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As Boolean
        Return SaveResponseToFile(FullFileName, URL, PrepPostData(PostData))
    End Function
    Function SaveResponseToFile(ByVal FullFileName As String, ByVal URL As Uri, ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As Boolean
        Return SaveResponseToFile(FullFileName, URL, PrepPostData(PostData))
    End Function
#End Region

#Region "Get Image"
    Public Function GetImage(ByVal URL As String) As System.Drawing.Image
        Try
            GetImage = System.Drawing.Image.FromStream(SendRequest(URL).GetResponseStream)
        Catch
            GetImage = Nothing
        End Try
    End Function
    Public Function GetImage(ByVal URL As Uri) As System.Drawing.Image
        Try
            GetImage = System.Drawing.Image.FromStream(SendRequest(URL).GetResponseStream)
        Catch
            GetImage = Nothing
        End Try
    End Function
#End Region

#Region "PostToURL"
    Public Sub PostToURL(ByVal URL As String, Optional ByVal PostData As String = "")
        SendRequest(URL, PostData)
    End Sub
    Public Sub PostToURL(ByVal URL As Uri, Optional ByVal PostData As String = "")
        SendRequest(URL, PostData)
    End Sub
    Public Sub PostToURL(ByVal URL As String, ByRef PostData As Dictionary(Of String, String))
        PostToURL(URL, PrepPostData(PostData))
    End Sub
    Public Sub PostToURL(ByVal URL As Uri, ByRef PostData As Dictionary(Of String, String))
        PostToURL(URL, PrepPostData(PostData))
    End Sub
#End Region

#Region "Private Methods"
    Private Function PrepPostData(ByRef PostData As IEnumerable(Of KeyValuePair(Of String, String))) As String
        PrepPostData = ""  ''// TODO: properly encode post data
        For Each pair As KeyValuePair(Of String, String) In PostData
            PrepPostData += pair.Key & "=" & pair.Value & "&"
        Next pair
        PrepPostData = PrepPostData.Remove(PrepPostData.Length - 1)
    End Function

    Private Function SendRequest(ByVal URL As String, Optional ByVal PostData As String = "") As HttpWebResponse
        Dim URL2 As Uri = Nothing
        If Uri.TryCreate(URL, UriKind.Absolute, URL2) Then
            Return SendRequest(URL2, PostData)
        Else
            Return Nothing
        End If
    End Function
    Private Function SendRequest(ByVal URL As Uri, Optional ByVal PostData As String = "") As HttpWebResponse
        Dim Request As HttpWebRequest = HttpWebRequest.Create(URL)

        Request.CookieContainer = Cookies
        Request.Timeout = TimeOut
        Request.UserAgent = Agent

        If PostData.Length > 0 Then
            Request.Method = "POST" ''// TODO: allow explicitly setting METHOD and Content-type for request via properties
            Request.ContentType = "application/x-www-form-urlencoded"
            Dim sw As New IO.StreamWriter(Request.GetRequestStream())
            sw.Write(PostData)
            sw.Close()
        End If

        Return Request.GetResponse()
    End Function
#End Region
End Class

Answer 2

CookieContainer is designed just like browser cookie store. So it can contain cookies in any sites because it will handle the domain path as well as expiry. I can tell that it possible to have any domain in the same container, so any web request should also possible to have the same container.

You should notice that CookieContainer has a bug on .Add(Cookie) and .GetCookies(uri) method.

See the details and fix here:

http://dot-net-expertise.blogspot.com/2009/10/cookiecontainer-domain-handling-bug-fix.html