从Google ReCaptcha Scraping获取Bad Captcha图像

Question

我正在尝试加载Captcha,然后在WebBrowser控件中渲染它们然后复制/粘贴图像并将其渲染到图片框中.

为什么不立即将图片直接下载到PictureBox中,这样可以减少CPU使用率和内存,这个解决方案适用于任何其他更高级的验证码服务,称为Solve Media(如果您查看图像URL,则使用Solve Media)下次你试图查看它时,它会给你一个假的错误catpcha图像).

但是现在我需要支持ReCaptcha Captcha系统,以便以更快的速度自动化我的机器人,然后只刷新网页并等待渲染.

所以我就写我的代码在这里,据我了解,我只是缺少仿效HTML请求的属性之一,我得到了用户代理伪造作为一个真正的Internet Explorer 8,我认为这个问题是饼干看起来有点它生成一个我无法弄清楚在哪里的cookie,但我也想通过下载Javascript文件得到一个Cookie.

无论哪种方式谷歌ReCaptcha试图欺骗你一个假的Captcha,你不能阅读,在你的脸上擦你不做正确的事情.当你看到2个黑色圆圈时,我发现它显然是假的.

这是Bad Captcha和Good Captcha的一个例子

有一次,我记得验证码了,如果你从那里它放在我不知道怎么说,因为工作我下载的一切权本地实际域加载验证码图片莫名其妙地知道其他安全功能？但他们似乎已经删除了这个功能.(实际上它存在于某些网站上似乎默认是禁用的,很容易欺骗它使用Referer标头)

我不打算在这里欺骗任何东西我仍然会手动输入这些Captcha,但是我想要更快地输入它们然后通常需要渲染页面.

我希望Captcha成为那些街道号码......或者至少2个单词没有那些黑色圆圈.

无论如何这里是我的当前代码.

Dim newCaptcha = New Captcha
Dim myUserAgent As String = ""
Dim myReferer As String = "http://www.google.com/recaptcha/demo/"
Dim outputSite As String = HTTP.HTTPGET("http://www.google.com/recaptcha/demo/", "", "", "", myUserAgent, myReferer)
Dim recaptchaChallengeKey = GetBetween(outputSite, "http://www.google.com/recaptcha/api/challenge?k=", """")

'Google ReCaptcha Captcha
outputSite = HTTP.HTTPGET("http://www.google.com/recaptcha/api/challenge?k=" & recaptchaChallengeKey, "", "", "", myUserAgent, myReferer)

'outputSite = outputSite.Replace("var RecaptchaState = {", "{""RecaptchaState"": {")
'outputSite = outputSite.Replace("};", "}}")
'Dim jsonDictionary As Dictionary(Of String, Object) = New JavaScriptSerializer().Deserialize(Of Dictionary(Of String, Object))(outputSite)
Dim recaptchaChallenge = GetBetween(outputSite, "challenge : '", "',")
outputSite = HTTP.HTTPGET("http://www.google.com/recaptcha/api/js/recaptcha.js", "", "", "", myUserAgent, myReferer) 'This page looks useless but it seems the javascript loads this anyways, maybe this why I get bad captchas?

If HTTP.LoadWebImageToPictureBox(newCaptcha.picCaptcha, "http://www.google.com/recaptcha/api/image?c=" & recaptchaChallenge, myUserAgent, myReferer) = False Then
    MessageBox.Show("Recaptcha Image loading failed!")
Else
    Dim newWork As New Work
    newWork.CaptchaForm = newCaptcha
    newWork.AccountId = 1234 'ID of Accounts.
    newWork.CaptchaHash = "recaptcha_challenge_field=" & recaptchaChallenge
    newWork.CaptchaType = "ReCaptcha"
    Works.Add(newWork)
    newCaptcha.Show()
End If

这是我使用的HTTP类.

Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.Net
Imports System.IO
Public Class HTTP

    Public StoredCookies As New CookieContainer

    Public Function HTTPGET(ByVal url As String, ByVal proxyname As String, ByVal proxylogin As String, ByVal proxypassword As String, ByVal userAgent As String, ByVal referer As String) As String
        Dim resp As HttpWebResponse
        Dim req As HttpWebRequest = DirectCast(WebRequest.Create(url), HttpWebRequest)

        If userAgent = "" Then
            userAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)"
        End If
        req.UserAgent = userAgent
        req.Referer = referer
        req.AllowAutoRedirect = True
        req.ReadWriteTimeout = 5000
        req.CookieContainer = StoredCookies
        req.Headers.Set("Accept-Language", "en-us")

        req.KeepAlive = True
        req.Method = "GET"

        Dim stream_in As StreamReader

        If proxyname <> "" Then
            Dim proxyIP As String = proxyname.Split(New Char() {":"})(0)
            Dim proxyPORT As Integer = CInt(proxyname.Split(New Char() {":"})(1))

            Dim proxy As New WebProxy(proxyIP, proxyPORT)
            'if proxylogin is an empty string then don't use proxy credentials (open proxy)
            If proxylogin <> "" Then
                proxy.Credentials = New NetworkCredential(proxylogin, proxypassword)
            End If
            req.Proxy = proxy
        End If

        Dim response As String = ""
        Try
            resp = DirectCast(req.GetResponse(), HttpWebResponse)
            StoredCookies.Add(resp.Cookies)
            stream_in = New StreamReader(resp.GetResponseStream())
            response = stream_in.ReadToEnd()
            stream_in.Close()
        Catch ex As Exception
        End Try
        Return response
    End Function


    Public Function LoadWebImageToPictureBox(ByVal pb As PictureBox, ByVal ImageURL As String, ByVal userAgent As String, ByVal referer As String) As Boolean
        Dim bAns As Boolean

        Try
            Dim resp As WebResponse
            Dim req As HttpWebRequest

            Dim sURL As String = Trim(ImageURL)

            If Not sURL.ToLower().StartsWith("http://") Then sURL = "http://" & sURL

            req = DirectCast(WebRequest.Create(sURL), HttpWebRequest)

            If userAgent = "" Then
                userAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)"
            End If
            req.UserAgent = userAgent
            req.Referer = referer
            req.AllowAutoRedirect = True
            req.ReadWriteTimeout = 5000
            req.CookieContainer = StoredCookies
            req.Headers.Set("Accept-Language", "en-us")

            req.KeepAlive = True
            req.Method = "GET"

            resp = req.GetResponse()
            If Not resp Is Nothing Then
                Dim remoteStream As Stream = resp.GetResponseStream()
                Dim objImage As New MemoryStream
                Dim bytesProcessed As Integer = 0
                Dim myBuffer As Byte()
                ReDim myBuffer(1024)
                Dim bytesRead As Integer
                bytesRead = remoteStream.Read(myBuffer, 0, 1024)
                Do While (bytesRead > 0)
                    objImage.Write(myBuffer, 0, bytesRead)
                    bytesProcessed += bytesRead
                    bytesRead = remoteStream.Read(myBuffer, 0, 1024)
                Loop
                pb.Image = Image.FromStream(objImage)
                bAns = True
                objImage.Close()
            End If
        Catch ex As Exception
            bAns = False
        End Try

        Return bAns
    End Function
End Class

编辑:我想出了这个谷歌Javascript Clientside混淆加密系统的问题

http://www.google.com/js/th/1lOyLe_nzkTfeM2GpTkE65M1Lr8y0MC8hybXoEd-x1s.js

我仍然希望能够打败它而不使用沉重的webbrowser也许一些轻量级的快速javascript评估控件？在unobfuscating它和将它移植到VB.NET,因为只要我做到这一点,他们可能会改变几个变量或加密完全和我没有白白所有这些工作,所以我想要的东西,更智能的无点.此时我甚至不知道URL是如何生成的,它现在看起来似乎是静态的,它可能是一个真实的文件,而不仅仅是生成时间的文件.

原来,_challenge这给该挑战的图像页面只是一个诱饵挑战..这一挑战,然后被替换(可能是加密的？)使用变量T1,T2,T3,客户面似乎这种加密每次不使用,如果你传递它,一旦你获得访问做我想做的几乎我的代码工作,但它停止工作在非常随机的时间间隔,我想要一些更坚实的东西,我可以无人看管几个星期.

Answer 1

我有同样的问题,并找到了一个解决方案,它不会提供最简单的验证码,但至少图像更容易.结果将是一个可读的单词和一个模糊的.

我发现下载"recaptcha/api/reload"对于实现这一点非常重要.也许它可以添加"cachestop"参数,也许是引用者.

data = UrlMgr("http://www.google.com/recaptcha/api/challenge?k=%s&cachestop=%.17f" % (id, random.random()), referer=referer, nocache=True).data
challenge = re.search("challenge : '(.*?)',", data).group(1)
server = re.search("server : '(.*?)',", data).group(1)
# this step is super important to get readable captchas - normally we could take the "c" from above and already retrieve a captcha but
# this one would be barely readable
reloadParams["c"] = challenge
reloadParams["k"] = id
reloadParams["lang"] = "de"
reloadParams["reason"] = "i"
reloadParams["type"] = "image"
data = UrlMgr("http://www.google.com/recaptcha/api/reload" , params=reloadParams, referer=referer, nocache=True).data
challenge = textextract(data, "Recaptcha.finish_reload('", "',")
return challenge, solveCaptcha(UrlMgr("%simage" % (server), params={"c":challenge}, referer=referer))

对于进一步的改进,我的猜测是"th"参数用于检测机器人.它是由一些复杂的JavaScript生成的,我自己没有调试.