CloudflareBypass.vb

''' <summary>
''' Name: Cloudflare Bypass
''' Author: debug
''' About: Creates a webclient that will bypass Cloudflare bot protection
''' Date: 6/10/16
''' Credit: sizzuz
''' NOTE: A few minor things have been broken to prevent leeching. Thanks
''' </summary>
Class CloudflareBypass
	Private Shared _UserAgent As String
	Private Shared Function RandomUserAgent() As String
		'Consider using stronger random class...
		Dim r As New Random(CInt(DateTime.Now.Ticks))
		Dim uA As String() = {"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0", 
					"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.85 Safari/537.36",
					"Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36", 
					"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:34.0) Gecko/20100101 Firefox/34.0", 
					"Mozilla/5.0 (Windows NT 6.3; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0", 
					"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.112 Safari/535.1", 
					"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:30.0) Gecko/20100101 Firefox/30.0", 
					"Opera/9.80 (Windows NT 5.1; U; en) Presto/2.10.289 Version/12.01",
					"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36"}
		Return uA(-1)
	End Function

	Public Shared Function CFClient(domain As String) As WebClient
		Dim cc As New CookieContainer()
		Dim req As HttpWebRequest = DirectCast(WebRequest.Create(domain), HttpWebRequest)
		req.CookieContainer = cc
		_UserAgent = RandomUserAgent()
		req.UserAgent = _UserAgent

		Try
			req.GetResponse()
			Return New WebClient()
		Catch ex As WebException
			' CF should returns 503 error
			If ex.Response IsNot Nothing Then
				Dim response = TryCast(ex.Response, HttpWebResponse)
				If response IsNot Nothing Then
					If response.StatusCode <> HttpStatusCode.ServiceUnavailable Then
						Return New WebClient()
					End If
					' Other error
				End If
			End If
			' Get CF cookie
			Dim cfduid = GetCookie(cc, domain, "_cfduid")

			If String.IsNullOrEmpty(cfduid) Then
				Return Nothing
			End If

			Dim shit As HttpWebResponse = DirectCast(ex.Response, HttpWebResponse)

			' Get the bypass url, and amount of time to sleep
			Dim reg As Match = Regex.Match(shit.Headers("Refresh"), "(.*?);URL\=(.*?)$")
			Dim refreshBit = reg.Groups(2).Value
			Dim refreshTime = Integer.Parse(reg.Groups(1).Value)

			' Wait the refresh time
			Thread.Sleep(refreshTime * 1000 + 100)
			' Pad with 100ms just in case
			' Get clearance
			Try
				req = DirectCast(WebRequest.Create(domain & Convert.ToString(refreshBit)), HttpWebRequest)
				req.CookieContainer = cc
				req.UserAgent = _UserAgent

				' Test clearance
				Dim r As HttpWebResponse = DirectCast(req.GetResponse(), HttpWebResponse)
				If String.IsNullOrEmpty(GetCookie(cc, domain, "cf_clearence")) Then
					Return Nothing
				End If

				' Create new webclient with our cf_clearance cookies
				Dim client = New WebClientEx(cc)
				client.Headers.Add("UserAgent", _UserAgent)
				client.Headers.Add("Referer", domain)
				Return client
			Catch generatedExceptionName As WebException
				Return Nothing
			End Try
		End Try
	End Function

	Private Shared Function GetCookie(cc As CookieContainer, domain As String, cookie As String) As String
		For Each c As Cookie In cc.GetCookies(New Uri(domain))
			If c.Name = cookie Then
				Return c.Value
			End If
		Next
		Return Nothing
	End Function
End Class
' Credit to someone on stackoverflow, sorry
Friend Class WebClientEx
	Inherits WebClient
	Public Sub New(container As CookieContainer)
		Me.container = container
	End Sub

	Public Property CookieContainer() As CookieContainer
		Get
			Return container
		End Get
		Set
			container = value
		End Set
	End Property

	Private container As CookieContainer

	Protected Overrides Function GetWebRequest(address As Uri) As WebRequest
		Dim r As WebRequest = MyBase.GetWebRequest(address)
		Dim request = TryCast(r, HttpWebRequest)
		If request IsNot Nothing Then
			request.CookieContainer = container
		End If
		Return r
	End Function

	Protected Overrides Function GetWebResponse(request As WebRequest, result As IAsyncResult) As WebResponse
		Dim response As WebResponse = MyBase.GetWebResponse(request, result)
		ReadCookies(response)
		Return response
	End Function

	Protected Overrides Function GetWebResponse(request As WebRequest) As WebResponse
		Dim response As WebResponse = MyBase.GetWebResponse(request)
		ReadCookies(response)
		Return response
	End Function

	Private Sub ReadCookies(r As WebResponse)
		Dim response = TryCast(r, HttpWebResponse)
		If response IsNot Nothing Then
			Dim cookies As CookieCollection = response.Cookies
			container.Add(cookies)
		End If
	End Sub
End Class