js逆向入门

柔情只为你懂 2023-05-29 02:38 48阅读 0赞

[中国土地市场网][Link 1]

### 1.分析请求过程 ###

![在这里插入图片描述][20191101160248531.png]  
在控制台中获取相应的参数  
![在这里插入图片描述][20191101160937208.png]

### 2.分析js并修改参数 ###

### 构建相应的爬虫代码 ###

# -*- coding: utf-8 -*-
    # @Time    : 2019/11/1 9:45
    # @Author  :
    
    import os
    import re
    
    import requests
    from lxml import etree
    
    
    def generate_signature(value):
        """
        generate _signature parameter
        :param value:share_url id
        :return:signature string
        """
        cwd = os.path.dirname(__file__)
        p = os.popen('cd %s && node landchina.js %s' % (cwd, value))
        return p.readlines()[0]
    
    
    def landchina():
        # 构建session会话
        s = requests.Session()
        headers = { 
            'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
            'Accept-Language': 'zh-CN,zh;q=0.9',
            'Cache-Control': 'no-cache',
            'Connection': 'keep-alive',
            'Host': 'www.landchina.com',
            'Pragma': 'no-cache',
            'Sec-Fetch-Mode': 'navigate',
            'Sec-Fetch-Site': 'none',
            'Sec-Fetch-User': '?1',
            'Upgrade-Insecure-Requests': '1',
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36',
        }
        s.headers = headers
    
        # 第一次请求
        url = "https://www.landchina.com/default.aspx?tabid=226"
        resp1 = s.get(url=url)
    
        cookie1 = resp1.headers["Set-Cookie"]
        cookie_re = "(security_session_verify=\w+;)"
        security_session_verify = "".join(re.findall(cookie_re, cookie1))
        security_session_verify_url = generate_signature("https://www.landchina.com/default.aspx?tabid=226").strip()
    
        s.headers = { 
            'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
            'Accept-Language': 'zh-CN,zh;q=0.9',
            'Cache-Control': 'no-cache',
            'Connection': 'keep-alive',
            'Cookie': security_session_verify + " srcurl=" + security_session_verify_url[
                                                             security_session_verify_url.rfind("=") + 1:],
            'Host': 'www.landchina.com',
            'Pragma': 'no-cache',
            'Referer': 'https://www.landchina.com/default.aspx?tabid=226',
            'Sec-Fetch-Mode': 'navigate',
            'Sec-Fetch-Site': 'same-origin',
            'Upgrade-Insecure-Requests': '1',
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36',
        }
        var_re = "(security_verify_data.*)"
        var = "".join(re.findall(var_re, generate_signature("")))
    
        # 第二次请求
        url2 = "https://www.landchina.com/default.aspx?tabid=226&" + var
        resp2 = s.get(url2)
        cookie2 = resp2.headers["Set-Cookie"]
        cookie_re = "(security_session_mid_verify=\w+;)"
        security_session_mid_verify = "".join(re.findall(cookie_re, cookie2))
        s.headers = { 
            'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3',
            'Accept-Encoding': 'gzip, deflate, br',
            'Accept-Language': 'zh-CN,zh;q=0.9',
            'Cache-Control': 'no-cache',
            'Connection': 'keep-alive',
            'Cookie': '%s; %s' % (security_session_verify, security_session_mid_verify),
            'Host': 'www.landchina.com',
            'Pragma': 'no-cache',
            'Referer': url2,
            'Sec-Fetch-Mode': 'navigate',
            'Sec-Fetch-Site': 'same-origin',
            'Upgrade-Insecure-Requests': '1',
            'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36',
        }
    
        # 第三次请求
        rep = s.get(url=url)
        mytree = etree.HTML(rep.text)
    
        urls = mytree.xpath('//*[@id="TAB_contentTable"]//tr/td[@class="queryCellBordy"]/a')
        for ur in urls:
            title = "".join(ur.xpath(".//text()"))
            c_url = "https://www.landchina.com/"+"".join(ur.xpath("./@href"))
            data = { 
                "title" : title,
                "c_url": c_url,
            }
            print(data)
    
    
    if __name__ == '__main__':
        landchina()

[Link 1]: https://www.landchina.com/default.aspx?tabid=226
[20191101160248531.png]: https://img-blog.csdnimg.cn/20191101160248531.png
[20191101160937208.png]: https://img-blog.csdnimg.cn/20191101160937208.png