（三）JS逆向——爬取易车网

爬取易车网的车辆配置信息

所以主要就是确定这几个是怎么生成的

 搜索x-sign值的位置，打断点，找到构建x-sign的函数

 注意，一定要看清是否是正确的url，x-timestamp明显是时间戳

进入这个函数

 x-sign值，是对这个字符串做md5，这个字符串由三部分构成，参数、时间戳、和一个固定字符串

因此可以用python模拟构建sign值

 需要注意的是python用，json.dumps序列化，会加空格，所以在拼接参数的时候要注意空格的影响，还有确保拼接字符串的单引号和双引号是正确的

 如果想要序列化不加空格，可以用separators参数自定义

import json
json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))

import json
import requests
from functools import partial
import time
import hashlib
import subprocess
subprocess.Popen = partial(subprocess.Popen, encoding="utf-8")
import execjs


def get_time_stamp():
    return int(time.time()*1000)

def generate_sign(target):
    md5 = hashlib.md5()
    md5.update(target.encode())
    res = md5.hexdigest()
    return res


url = "https://mhapi.yiche.com/hcar/h_car/api/v1/param/get_param_details"

uuid = "000750ef-d6d6-45d8-9ed3-8864fcb3e6ad"

timestamp = get_time_stamp()

param = {"cityId": "1501","serialId": "7219"}

target = f'cid=508&param={json.dumps(param)}19DDD1FBDFF065D3A4DA777D2D7A81EC{timestamp}'

sign = generate_sign(target)

params = {
    "cid": "508",
    "param": json.dumps(param)
}

headers={
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36",
    "Content-Type":"application/json;charset=UTF-8",
    "Referer":"https://car.yiche.com/hongqihs5/peizhi/",
    "Cookie":"CIGUID=000750ef-d6d6-45d8-9ed3-8864fcb3e6ad; selectcity=320100; selectcityid=1501; selectcityName=%E5%8D%97%E4%BA%AC; auto_id=de6ccf16bb10303bb8ae4fc2243912ac; CIGDCID=sWtRAyHkEkcThDM7ie2xEKtbTS2GhB3m; Hm_lvt_610fee5a506c80c9e1a46aa9a2de2e44=1719905729; UserGuid=000750ef-d6d6-45d8-9ed3-8864fcb3e6ad; isWebP=true; locatecity=320100; bitauto_ipregion=58.213.147.125%3A%E6%B1%9F%E8%8B%8F%E7%9C%81%E5%8D%97%E4%BA%AC%E5%B8%82%3B1501%2C%E5%8D%97%E4%BA%AC%E5%B8%82%2Cnanjing; csids=7219_8156_5586; pageCount=3; Hm_lpvt_610fee5a506c80c9e1a46aa9a2de2e44=1719975723",
    "X-City-Id":"1501",
    "X-Ip-Address":"58.213.147.125",
    "X-Platform":"pc",
    "X-Sign":sign,
    "X-Timestamp":str(timestamp),
    "X-User-Guid":uuid
}



res = requests.get(url=url, params=params, headers=headers)
data = res.text
with open("config.txt", 'w', encoding='utf-8') as f:
    f.write(data)