帝王谷资源网 Design By www.wdxyy.com

  通过Fiddler抓包比较,基本可以确定是JavaScript生成加密Cookie导致原来的请求返回521。

发现问题:  

打开Fiddler软件,用浏览器打开目标站点(http://www.kuaidaili.com/proxylist/2/) 。可以发现浏览器对这个页面加载了两次,第一次返回521,第二次才正常返回数据。很多没有写过网站或是爬虫经验不足的童鞋,可能就会觉得奇怪为什么会这样?为什么浏览器可能正常返回数据而代码却不行?

Python爬虫如何破解JS加密的Cookie

  仔细观察两次返回的结果可以发现:

Python爬虫如何破解JS加密的Cookie

Python爬虫如何破解JS加密的Cookie

  1、第二次请求比第一次请求的Cookie内容多了个这个_ydclearance=0c316df6ea04c5281b421aa8-5570-47ae-9768-2510d9fe9107-1490254971

  2、第一次返回的内容一些复杂看不懂的JS代码,第二次返回的就是正确的内容

  其实这是网站反爬虫的常用手段。大致过程是这样的:首次请求数据时,服务端返回动态的混淆加密过的JS,而这段JS的作用是给Cookie添加新的内容用于服务端验证,此时返回的状态码是521。浏览器带上新的Cookie再次请求,服务端验证Cookie通过返回数据(这也是为嘛代码不能返回数据的原因)。

解决问题
  其实我第一次遇到这样的问题是,一开始想的就是既然你是用JS生成的Cookie, 那么我也可以将JS函数翻译成Python运行。但是最后还是发现我太傻太天真,因为现在的JS都流行混淆加密,原始的JS这样的:

function lq(VA) {
  var qo, mo = "", no = "", oo = [0x8c, 0xcd, 0x4c, 0xf9, 0xd7, 0x4d, 0x25, 0xba, 0x3c, 0x16, 0x96, 0x44, 0x8d, 0x0b, 0x90, 0x1e, 0xa3, 0x39, 0xc9, 0x86, 0x23, 0x61, 0x2f, 0xc8, 0x30, 0xdd, 0x57, 0xec, 0x92, 0x84, 0xc4, 0x6a, 0xeb, 0x99, 0x37, 0xeb, 0x25, 0x0e, 0xbb, 0xb0, 0x95, 0x76, 0x45, 0xde, 0x80, 0x59, 0xf6, 0x9c, 0x58, 0x39, 0x12, 0xc7, 0x9c, 0x8d, 0x18, 0xe0, 0xc5, 0x77, 0x50, 0x39, 0x01, 0xed, 0x93, 0x39, 0x02, 0x7e, 0x72, 0x4f, 0x24, 0x01, 0xe9, 0x66, 0x75, 0x4e, 0x2b, 0xd8, 0x6e, 0xe2, 0xfa, 0xc7, 0xa4, 0x85, 0x4e, 0xc2, 0xa5, 0x96, 0x6b, 0x58, 0x39, 0xd2, 0x7f, 0x44, 0xe5, 0x7b, 0x48, 0x2d, 0xf6, 0xdf, 0xbc, 0x31, 0x1e, 0xf6, 0xbf, 0x84, 0x6d, 0x5e, 0x33, 0x0c, 0x97, 0x5c, 0x39, 0x26, 0xf2, 0x9b, 0x77, 0x0d, 0xd6, 0xc0, 0x46, 0x38, 0x5f, 0xf4, 0xe2, 0x9f, 0xf1, 0x7b, 0xe8, 0xbe, 0x37, 0xdf, 0xd0, 0xbd, 0xb9, 0x36, 0x2c, 0xd1, 0xc3, 0x40, 0xe7, 0xcc, 0xa9, 0x52, 0x3b, 0x20, 0x40, 0x09, 0xe1, 0xd2, 0xa3, 0x80, 0x25, 0x0a, 0xb2, 0xd8, 0xce, 0x21, 0x69, 0x3e, 0xe6, 0x80, 0xfd, 0x73, 0xab, 0x51, 0xde, 0x60, 0x15, 0x95, 0x07, 0x94, 0x6a, 0x18, 0x9d, 0x37, 0x31, 0xde, 0x64, 0xdd, 0x63, 0xe3, 0x57, 0x05, 0x82, 0xff, 0xcc, 0x75, 0x79, 0x63, 0x09, 0xe2, 0x6c, 0x21, 0x5c, 0xe0, 0x7d, 0x4a, 0xf2, 0xd8, 0x9c, 0x22, 0xa3, 0x3d, 0xba, 0xa0, 0xaf, 0x30, 0xc1, 0x47, 0xf4, 0xca, 0xee, 0x64, 0xf9, 0x7b, 0x55, 0xd5, 0xd2, 0x4c, 0xc9, 0x7f, 0x25, 0xfe, 0x48, 0xcd, 0x4b, 0xcc, 0x81, 0x1b, 0x05, 0x82, 0x38, 0x0e, 0x83, 0x19, 0xe3, 0x65, 0x3f, 0xbf, 0x16, 0x88, 0x93, 0xdd, 0x3b];
  qo = "qo=241; do{oo[qo]=(-oo[qo])&0xff; oo[qo]=(((oo[qo]3)|((oo[qo]<<5)&0xff))-70)&0xff;} while(--qo>=2);";
  eval(qo);
  qo = 240;
  do {
    oo[qo] = (oo[qo] - oo[qo - 1]) & 0xff;
  } while (--qo >= 3);
  qo = 1;
  for (; ;) {
    if (qo > 240) break;
    oo[qo] = ((((((oo[qo] + 2) & 0xff) + 76) & 0xff) << 1) & 0xff) | (((((oo[qo] + 2) & 0xff) + 76) & 0xff)  7);
    qo++;
  }
  po = "";
  for (qo = 1; qo < oo.length - 1; qo++) if (qo % 6) po += String.fromCharCode(oo[qo] ^ VA);
  eval("qo=eval;qo(po);");
}

  看到这样的JS代码,我只能说原谅我JS能力差,还原不了。。。

  但是前端经验丰富的童鞋马上就能想到还有种方法可解,那就是利用浏览器的JS代码调试功能。这样一切就迎刃而解,新建一个html文件,将第一次返回的html原文复制进去,保存用浏览器打开,在eval之前打上断点,看到这样的输出:

Python爬虫如何破解JS加密的Cookie

  可以看到这个变量po为document.cookie='_ydclearance=0c316df6ea04c5281b421aa8-5570-47ae-9768-2510d9fe9107-1490254971; expires=Thu, 23-Mar-17 07:42:51 GMT; domain=.kuaidaili.com; path=/'; window.document.location=document.URL,下面还有个eval("qo=eval;qo(po);")。JS里面的eval和Python的差不多,第二句的意思就是将eval方法赋给qo。然后去eval字符串po。而字符串po的前半段的意思是给浏览器添加Cooklie,后半段window.document.location=document.URL是刷新当前页面。

  这也印证了我上面的说法,首次请求没有Cookie,服务端回返回一段生成Cookie并自动刷新的JS代码。浏览器拿到代码能够成功执行,带着新的Cookie再次请求获取数据。而Python拿到这段代码就只能停留在第一步。

  那么如何才能使Python也能执行这段JS呢,答案是PyV8。V8是Chromium中内嵌的javascript引擎,号称跑的最快。PyV8是用Python在V8的外部API包装了一个python壳,这样便可以使python可以直接与javascript操作。PyV8的安装大家可以自行百度。

代码

  分析完成,下面切入正题撸代码。

  首先是正常请求网页,返回带加密的JS函数的html:

import re
import PyV8
import requests

TARGET_URL = "http://www.kuaidaili.com/proxylist/1/"

def getHtml(url, cookie=None):
  header = {
    "Host": "www.kuaidaili.com",
    'Connection': 'keep-alive',
    'Cache-Control': 'max-age=0',
    'Upgrade-Insecure-Requests': '1',
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
    'Accept-Encoding': 'gzip, deflate, sdch',
    'Accept-Language': 'zh-CN,zh;q=0.8',
  }
  html = requests.get(url=url, headers=header, timeout=30, cookies=cookie).content
  return html
# 第一次访问获取动态加密的JS
first_html = getHtml(TARGET_URL)

  由于返回的是html,并不单纯的JS函数,所以需要用正则提取JS函数的参数的参数。

Python爬虫如何破解JS加密的Cookie

# 提取其中的JS加密函数
js_func = ''.join(re.findall(r'(function .*"\D+\((\d+)\)\"', first_html))

print 'get ja arg:\n', js_arg

  还有一点需要注意,在JS函数中并没有返回cookie,而是直接将cookie set到浏览器,所以我们需要将eval("qo=eval;qo(po);")替换成return po。这样就能成功返回po中的内容。

def executeJS(js_func_string, arg):
  ctxt = PyV8.JSContext()
  ctxt.enter()
  func = ctxt.eval("({js})".format(js=js_func_string))
  return func(arg)
# 修改JS函数,使其返回Cookie内容
js_func = js_func.replace('eval("qo=eval;qo(po);")', 'return po')

# 执行JS获取Cookie
cookie_str = executeJS(js_func, js_arg)

  这样返回的cookie是字符串格式,但是用requests.get()需要字典形式,所以将其转换成字典:

def parseCookie(string):
  string = string.replace("document.cookie='", "")
  clearance = string.split(';')[0]
  return {clearance.split('=')[0]: clearance.split('=')[1]}
# 将Cookie转换为字典格式
cookie = parseCookie(cookie_str)

  最后带上解析出来的Cookie再次访问网页,成功获取数据:

# 带上Cookie再次访问url,获取正确数据
print getHtml(TARGET_URL, cookie)[0:500]

  下面是完整代码:

# -*- coding: utf-8 -*-
""" ------------------------------------------------- File Name: demo_1.py.py Description : Python爬虫—破解JS加密的Cookie 快代理网站为例:http://www.kuaidaili.com/proxylist/1/ Document: Author : JHao date: 2017/3/23 ------------------------------------------------- Change Activity: 2017/3/23: 破解JS加密的Cookie ------------------------------------------------- """
__author__ = 'JHao'

import re
import PyV8
import requests

TARGET_URL = "http://www.kuaidaili.com/proxylist/1/"

def getHtml(url, cookie=None):
  header = {
    "Host": "www.kuaidaili.com",
    'Connection': 'keep-alive',
    'Cache-Control': 'max-age=0',
    'Upgrade-Insecure-Requests': '1',
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
    'Accept-Encoding': 'gzip, deflate, sdch',
    'Accept-Language': 'zh-CN,zh;q=0.8',
  }
  html = requests.get(url=url, headers=header, timeout=30, cookies=cookie).content
  return html

def executeJS(js_func_string, arg):
  ctxt = PyV8.JSContext()
  ctxt.enter()
  func = ctxt.eval("({js})".format(js=js_func_string))
  return func(arg)

def parseCookie(string):
  string = string.replace("document.cookie='", "")
  clearance = string.split(';')[0]
  return {clearance.split('=')[0]: clearance.split('=')[1]}

# 第一次访问获取动态加密的JS
first_html = getHtml(TARGET_URL)

# first_html = """
# <html><body><script language="javascript"> window.onload=setTimeout("lu(158)", 200); function lu(OE) {var qo, mo="", no="", oo = [0x64,0xaa,0x98,0x3d,0x56,0x64,0x8b,0xb0,0x88,0xe1,0x0d,0xf4,0x99,0x31,0xd8,0xb6,0x5d,0x73,0x98,0xc3,0xc4,0x7a,0x1e,0x38,0x9d,0xe8,0x8d,0xe4,0x0a,0x2e,0x6c,0x45,0x69,0x41,0xe5,0xd0,0xe5,0x11,0x0b,0x35,0x7b,0xe4,0x09,0xb1,0x2b,0x6d,0x82,0x7c,0x25,0xdd,0x70,0x5a,0xc4,0xaa,0xd3,0x74,0x98,0x42,0x3c,0x60,0x2d,0x42,0x66,0xe0,0x0a,0x2e,0x96,0xbb,0xe2,0x1d,0x38,0xdc,0xb1,0xd6,0x0e,0x0d,0x76,0xae,0xc3,0xa9,0x3b,0x62,0x47,0x40,0x15,0x93,0xb7,0xee,0xc3,0x3e,0xfd,0xd3,0x0d,0xf6,0x61,0xdc,0xf1,0x2c,0x54,0x8c,0x90,0xfa,0x24,0x5b,0x83,0x0c,0x75,0xaf,0x18,0x01,0x7e,0x68,0xe0,0x0a,0x72,0x1e,0x88,0x33,0xa7,0xcc,0x31,0x9b,0xf3,0x1a,0xf2,0x9a,0xbf,0x58,0x83,0xe4,0x87,0xed,0x07,0x7e,0xe2,0x00,0xe9,0x92,0xc9,0xe8,0x59,0x7d,0x56,0x8d,0xb5,0xb2,0x6c,0xe0,0x49,0x73,0xfc,0xe7,0x20,0x49,0x34,0x09,0x71,0xeb,0x60,0xfd,0x8e,0xad,0x0f,0xb9,0x2e,0x77,0xdc,0x74,0x9b,0xbf,0x8f,0xa5,0x8d,0xb8,0xb0,0x06,0xac,0xc5,0xe9,0x10,0x12,0x77,0x9b,0xb1,0x19,0x4e,0x64,0x5c,0x00,0x98,0xc6,0xed,0x98,0x0d,0x65,0x11,0x35,0x9e,0xf4,0x30,0x93,0x4b,0x00,0xab,0x20,0x8f,0x29,0x4f,0x27,0x8c,0xc2,0x6a,0x04,0xfb,0x51,0xa3,0x4b,0xef,0x09,0x30,0x28,0x4d,0x25,0x8e,0x76,0x58,0xbf,0x57,0xfb,0x20,0x78,0xd1,0xf7,0x9f,0x77,0x0f,0x3a,0x9f,0x37,0xdb,0xd3,0xfc,0x14,0x39,0x11,0x3b,0x94,0x8c,0xad,0x8e,0x5c,0xd3,0x3b];qo = "qo=251; do{oo[qo]=(-oo[qo])&0xff; oo[qo]=(((oo[qo]4)|((oo[qo]<<4)&0xff))-0)&0xff;} while(--qo>=2);"; eval(qo);qo = 250; do { oo[qo] = (oo[qo] - oo[qo - 1]) & 0xff; } while (-- qo >= 3 );qo = 1; for (;;) { if (qo > 250) break; oo[qo] = ((((((oo[qo] + 200) & 0xff) + 121) & 0xff) << 6) & 0xff) | (((((oo[qo] + 200) & 0xff) + 121) & 0xff)  2); qo++;}po = ""; for (qo = 1; qo < oo.length - 1; qo++) if (qo % 5) po += String.fromCharCode(oo[qo] ^ OE);eval("qo=eval;qo(po);");} </script> </body></html>
# """

# 提取其中的JS加密函数
js_func = ''.join(re.findall(r'(function .*"\D+\((\d+)\)\"', first_html))

print 'get ja arg:\n', js_arg

# 修改JS函数,使其返回Cookie内容
js_func = js_func.replace('eval("qo=eval;qo(po);")', 'return po')

# 执行JS获取Cookie
cookie_str = executeJS(js_func, js_arg)

# 将Cookie转换为字典格式
cookie = parseCookie(cookie_str)

print cookie

# 带上Cookie再次访问url,获取正确数据
print getHtml(TARGET_URL, cookie)[0:500]

以上就是Python爬虫如何破解JS加密的Cookie的详细内容,更多关于python 爬虫破解js加密的资料请关注其它相关文章!

标签:
python,爬虫,python,破解js加密,python,破解cooki

帝王谷资源网 Design By www.wdxyy.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
帝王谷资源网 Design By www.wdxyy.com

稳了!魔兽国服回归的3条重磅消息!官宣时间再确认!

昨天有一位朋友在大神群里分享,自己亚服账号被封号之后居然弹出了国服的封号信息对话框。

这里面让他访问的是一个国服的战网网址,com.cn和后面的zh都非常明白地表明这就是国服战网。

而他在复制这个网址并且进行登录之后,确实是网易的网址,也就是我们熟悉的停服之后国服发布的暴雪游戏产品运营到期开放退款的说明。这是一件比较奇怪的事情,因为以前都没有出现这样的情况,现在突然提示跳转到国服战网的网址,是不是说明了简体中文客户端已经开始进行更新了呢?