Comment puis-je obtenir html de la page avec cloudflare ddos portection?

J'ai aussi rencontré ce problème il y a quelques temps. Le réel solution serait de résoudre le défi de la cloudflare sites web vous donne (vous avez besoin de calculer une réponse correcte à l'aide de javascript, de le retourner, et puis vous recevez un cookie de votre jeton avec laquelle vous pouvez continuer à afficher le site web). Donc tout ce que vous obtiendriez normalement, c'est une page comme

En fin de compte, je viens d'appeler un python script avec une coquille d'exécuter. J'ai utilisé les modules fournis dans cette github fourche. Ceci pourrait servir de point de départ pour mettre en œuvre le contournement de la cloudflare anti-dDoS page en C# aswell.

Pour info, le script python que j'ai écrit pour mon usage personnel seulement écrit le cookie dans un fichier. J'ai lu que plus tard, à nouveau à l'aide de C# et de le stocker dans un CookieJar pour continuer à naviguer sur la page à l'intérieur de C#.

#!/usr/bin/env python
import cfscrape
import sys

scraper = cfscrape.create_scraper() # returns a requests.Session object
fd = open("cookie.txt", "w")
c = cfscrape.get_cookie_string(sys.argv[1])
fd.write(str(c))
fd.close()  
print(c)

EDIT: Pour répéter cela, cela n'a que PEU à voir avec les cookies! Cloudflare vous oblige à résoudre un RÉEL défi à l'aide des commandes javascript. Ce n'est pas aussi facile que d'accepter un cookie et l'utiliser plus tard. Regardez https://github.com/Anorov/cloudflare-scrape/blob/master/cfscrape/init.py et le ~40 lignes de javascript émulation pour résoudre le défi.

Edit2: au Lieu d'écrire quelque chose de contourner la protection, j'ai aussi vu des gens utiliser à part entière du navigateur d'objet (c'est pas un headless browser) pour aller sur le site et vous abonner à certains événements lorsque la page est chargée. Utiliser le WebBrowser classe pour créer un infinetly petite fenêtre de navigateur et de vous abonner à la appropriée des événements.

Edit3:
Bon, j'ai effectivement mis en œuvre le C#. Il utilise le Moteur JavaScript Jint pour .NET, disponible via https://www.nuget.org/packages/Jint

Le cookie de code de traitement est laid parce que parfois les HttpResponse classe ne capte pas les cookies, bien que l'en-tête contient un Set-Cookie section.

using System;
using System.Net;
using System.IO;
using System.Text.RegularExpressions;
using System.Web;
using System.Collections;
using System.Threading;
namespace Cloudflare_Evader
{
public class CloudflareEvader
{
///<summary>
///Tries to return a webclient with the neccessary cookies installed to do requests for a cloudflare protected website.
///</summary>
///<param name="url">The page which is behind cloudflare's anti-dDoS protection</param>
///<returns>A WebClient object or null on failure</returns>
public static WebClient CreateBypassedWebClient(string url)
{
var JSEngine = new Jint.Engine(); //Use this JavaScript engine to compute the result.
//Download the original page
var uri = new Uri(url);
HttpWebRequest req =(HttpWebRequest) WebRequest.Create(url);
req.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0";
//Try to make the usual request first. If this fails with a 503, the page is behind cloudflare.
try
{
var res = req.GetResponse();
string html = "";
using (var reader = new StreamReader(res.GetResponseStream()))
html = reader.ReadToEnd();
return new WebClient();
}
catch (WebException ex) //We usually get this because of a 503 service not available.
{
string html = "";
using (var reader = new StreamReader(ex.Response.GetResponseStream()))
html = reader.ReadToEnd();
//If we get on the landing page, Cloudflare gives us a User-ID token with the cookie. We need to save that and use it in the next request.
var cookie_container = new CookieContainer();
//using a custom function because ex.Response.Cookies returns an empty set ALTHOUGH cookies were sent back.
var initial_cookies = GetAllCookiesFromHeader(ex.Response.Headers["Set-Cookie"], uri.Host); 
foreach (Cookie init_cookie in initial_cookies)
cookie_container.Add(init_cookie);
/* solve the actual challenge with a bunch of RegEx's. Copy-Pasted from the python scrapper version.*/
var challenge = Regex.Match(html, "name=\"jschl_vc\" value=\"(\\w+)\"").Groups[1].Value;
var challenge_pass = Regex.Match(html, "name=\"pass\" value=\"(.+?)\"").Groups[1].Value;
var builder = Regex.Match(html, @"setTimeout\(function\(\){\s+(var t,r,a,f.+?\r?\n[\s\S]+?a\.value =.+?)\r?\n").Groups[1].Value;
builder = Regex.Replace(builder, @"a\.value =(.+?) \+ .+?;", "$1");
builder = Regex.Replace(builder, @"\s{3,}[a-z](?: = |\.).+", "");
//Format the javascript..
builder = Regex.Replace(builder, @"[\n\\']", "");
//Execute it. 
long solved = long.Parse(JSEngine.Execute(builder).GetCompletionValue().ToObject().ToString());
solved += uri.Host.Length; //add the length of the domain to it.
Console.WriteLine("***** SOLVED CHALLENGE ******: " + solved);
Thread.Sleep(3000); //This sleeping IS requiered or cloudflare will not give you the token!!
//Retreive the cookies. Prepare the URL for cookie exfiltration.
string cookie_url = string.Format("{0}://{1}/cdn-cgi/l/chk_jschl", uri.Scheme, uri.Host);
var uri_builder = new UriBuilder(cookie_url);
var query = HttpUtility.ParseQueryString(uri_builder.Query);
//Add our answers to the GET query
query["jschl_vc"] = challenge;
query["jschl_answer"] = solved.ToString();
query["pass"] = challenge_pass;
uri_builder.Query = query.ToString();
//Create the actual request to get the security clearance cookie
HttpWebRequest cookie_req = (HttpWebRequest) WebRequest.Create(uri_builder.Uri);
cookie_req.AllowAutoRedirect = false;
cookie_req.CookieContainer = cookie_container;
cookie_req.Referer = url;
cookie_req.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0";
//We assume that this request goes through well, so no try-catch
var cookie_resp = (HttpWebResponse)cookie_req.GetResponse();
//The response *should* contain the security clearance cookie!
if (cookie_resp.Cookies.Count != 0) //first check if the HttpWebResponse has picked up the cookie.
foreach (Cookie cookie in cookie_resp.Cookies)
cookie_container.Add(cookie);
else //otherwise, use the custom function again
{
//the cookie we *hopefully* received here is the cloudflare security clearance token.
if (cookie_resp.Headers["Set-Cookie"] != null)
{
var cookies_parsed = GetAllCookiesFromHeader(cookie_resp.Headers["Set-Cookie"], uri.Host);
foreach (Cookie cookie in cookies_parsed)
cookie_container.Add(cookie);
}
else
{
//No security clearence? something went wrong.. return null.
//Console.WriteLine("MASSIVE ERROR: COULDN'T GET CLOUDFLARE CLEARANCE!");
return null;
}
}
//Create a custom webclient with the two cookies we already acquired.
WebClient modedWebClient = new WebClientEx(cookie_container);
modedWebClient.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0");
modedWebClient.Headers.Add("Referer", url);
return modedWebClient;
}
}
/* Credit goes to https://stackoverflow.com/questions/15103513/httpwebresponse-cookies-empty-despite-set-cookie-header-no-redirect 
(user https://stackoverflow.com/users/541404/cameron-tinker) for these functions 
*/
public static CookieCollection GetAllCookiesFromHeader(string strHeader, string strHost)
{
ArrayList al = new ArrayList();
CookieCollection cc = new CookieCollection();
if (strHeader != string.Empty)
{
al = ConvertCookieHeaderToArrayList(strHeader);
cc = ConvertCookieArraysToCookieCollection(al, strHost);
}
return cc;
}
private static ArrayList ConvertCookieHeaderToArrayList(string strCookHeader)
{
strCookHeader = strCookHeader.Replace("\r", "");
strCookHeader = strCookHeader.Replace("\n", "");
string[] strCookTemp = strCookHeader.Split(',');
ArrayList al = new ArrayList();
int i = 0;
int n = strCookTemp.Length;
while (i < n)
{
if (strCookTemp[i].IndexOf("expires=", StringComparison.OrdinalIgnoreCase) > 0)
{
al.Add(strCookTemp[i] + "," + strCookTemp[i + 1]);
i = i + 1;
}
else
al.Add(strCookTemp[i]);
i = i + 1;
}
return al;
}
private static CookieCollection ConvertCookieArraysToCookieCollection(ArrayList al, string strHost)
{
CookieCollection cc = new CookieCollection();
int alcount = al.Count;
string strEachCook;
string[] strEachCookParts;
for (int i = 0; i < alcount; i++)
{
strEachCook = al[i].ToString();
strEachCookParts = strEachCook.Split(';');
int intEachCookPartsCount = strEachCookParts.Length;
string strCNameAndCValue = string.Empty;
string strPNameAndPValue = string.Empty;
string strDNameAndDValue = string.Empty;
string[] NameValuePairTemp;
Cookie cookTemp = new Cookie();
for (int j = 0; j < intEachCookPartsCount; j++)
{
if (j == 0)
{
strCNameAndCValue = strEachCookParts[j];
if (strCNameAndCValue != string.Empty)
{
int firstEqual = strCNameAndCValue.IndexOf("=");
string firstName = strCNameAndCValue.Substring(0, firstEqual);
string allValue = strCNameAndCValue.Substring(firstEqual + 1, strCNameAndCValue.Length - (firstEqual + 1));
cookTemp.Name = firstName;
cookTemp.Value = allValue;
}
continue;
}
if (strEachCookParts[j].IndexOf("path", StringComparison.OrdinalIgnoreCase) >= 0)
{
strPNameAndPValue = strEachCookParts[j];
if (strPNameAndPValue != string.Empty)
{
NameValuePairTemp = strPNameAndPValue.Split('=');
if (NameValuePairTemp[1] != string.Empty)
cookTemp.Path = NameValuePairTemp[1];
else
cookTemp.Path = "/";
}
continue;
}
if (strEachCookParts[j].IndexOf("domain", StringComparison.OrdinalIgnoreCase) >= 0)
{
strPNameAndPValue = strEachCookParts[j];
if (strPNameAndPValue != string.Empty)
{
NameValuePairTemp = strPNameAndPValue.Split('=');
if (NameValuePairTemp[1] != string.Empty)
cookTemp.Domain = NameValuePairTemp[1];
else
cookTemp.Domain = strHost;
}
continue;
}
}
if (cookTemp.Path == string.Empty)
cookTemp.Path = "/";
if (cookTemp.Domain == string.Empty)
cookTemp.Domain = strHost;
cc.Add(cookTemp);
}
return cc;
}
}
/*Credit goes to  https://stackoverflow.com/questions/1777221/using-cookiecontainer-with-webclient-class
(user https://stackoverflow.com/users/129124/pavel-savara) */
public class WebClientEx : WebClient
{
public WebClientEx(CookieContainer container)
{
this.container = container;
}
public CookieContainer CookieContainer
{
get { return container; }
set { container = value; }
}
private CookieContainer container = new CookieContainer();
protected override WebRequest GetWebRequest(Uri address)
{
WebRequest r = base.GetWebRequest(address);
var request = r as HttpWebRequest;
if (request != null)
{
request.CookieContainer = container;
}
return r;
}
protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result)
{
WebResponse response = base.GetWebResponse(request, result);
ReadCookies(response);
return response;
}
protected override WebResponse GetWebResponse(WebRequest request)
{
WebResponse response = base.GetWebResponse(request);
ReadCookies(response);
return response;
}
private void ReadCookies(WebResponse r)
{
var response = r as HttpWebResponse;
if (response != null)
{
CookieCollection cookies = response.Cookies;
container.Add(cookies);
}
}
}
}

La fonction retournera un client web avec la solution des défis et des biscuits à l'intérieur. Vous pouvez l'utiliser comme suit:

static void Main(string[] args)
{
WebClient client = null;
while (client == null)
{
Console.WriteLine("Trying..");
client = CloudflareEvader.CreateBypassedWebClient("http://anilinkz.tv");
}
Console.WriteLine("Solved! We're clear to go");
Console.WriteLine(client.DownloadString("http://anilinkz.tv/anime-list"));
Console.ReadLine();
}

OriginalL'auteur Maximilian Gerhardt

Utilisation WebClient pour obtenir de l'html de la page,

J'ai écrit à la suite de la classe qui gère les cookies trop,

Il suffit de passer CookieContainer exemple dans le constructeur.

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net;
using System.Text;
namespace NitinJS
{
public class SmsWebClient : WebClient
{
public SmsWebClient(CookieContainer container, Dictionary<string, string> Headers)
: this(container)
{
foreach (var keyVal in Headers)
{
this.Headers[keyVal.Key] = keyVal.Value;
}
}
public SmsWebClient(bool flgAddContentType = true)
: this(new CookieContainer(), flgAddContentType)
{
}
public SmsWebClient(CookieContainer container, bool flgAddContentType = true)
{
this.Encoding = Encoding.UTF8;
System.Net.ServicePointManager.Expect100Continue = false;
ServicePointManager.MaxServicePointIdleTime = 2000;
this.container = container;
if (flgAddContentType)
this.Headers["Content-Type"] = "application/json";//"application/x-www-form-urlencoded";
this.Headers["Accept"] = "application/json, text/javascript, */*; q=0.01";//"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
//this.Headers["Accept-Encoding"] = "gzip, deflate";
this.Headers["Accept-Language"] = "en-US,en;q=0.5";
this.Headers["User-Agent"] = "Mozilla/5.0 (Windows NT 6.1; rv:23.0) Gecko/20100101 Firefox/23.0";
this.Headers["X-Requested-With"] = "XMLHttpRequest";
//this.Headers["Connection"] = "keep-alive";
}
private readonly CookieContainer container = new CookieContainer();
protected override WebRequest GetWebRequest(Uri address)
{
WebRequest r = base.GetWebRequest(address);
var request = r as HttpWebRequest;
if (request != null)
{
request.CookieContainer = container;
request.Timeout = 3600000; //20 * 60 * 1000
}
return r;
}
protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result)
{
WebResponse response = base.GetWebResponse(request, result);
ReadCookies(response);
return response;
}
protected override WebResponse GetWebResponse(WebRequest request)
{
WebResponse response = base.GetWebResponse(request);
ReadCookies(response);
return response;
}
private void ReadCookies(WebResponse r)
{
var response = r as HttpWebResponse;
if (response != null)
{
CookieCollection cookies = response.Cookies;
container.Add(cookies);
}
}
}
}

UTILISATION:

CookieContainer cookies = new CookieContainer();
SmsWebClient client = new SmsWebClient(cookies);
string html = client.DownloadString("http://www.google.com");

OriginalL'auteur Nitin Sawant