本帖最后由 xiaopacai888 于 2024-3-18 19:10 编辑
web爬虫逆向笔记：js逆向案例三 某道翻译（MD5加密、AES解密）
一、目标网址：aHR0cHM6Ly9mYW55aS55b3VkYW8uY29tL2luZGV4Lmh0bWwjLw==
二、接口分析
1、sign值生成逻辑
[JavaScript] 纯文本查看 复制代码 // c.a为crypto加密模块，直接导包替换就好
function j(e) {
return c.a.createHash("md5").update(e.toString()).digest("hex")
}
function k(e, t) {
return j(`client=${u}&mysticTime=${e}&product=${d}&key=${t}`)
}
const o = (new Date).getTime();
let e = 'fsdsogkndfokasodnaso'
// sign值生成
// e为固定值
// o为时间戳
sign = k(o, e)
2、整合封装代码
[JavaScript] 纯文本查看 复制代码 const Crypto = require("crypto");
const u = "fanyideskweb",
d = "webfanyi",
m = "client,mysticTime,product",
p = "1.0.0",
g = "web",
b = "fanyi.web",
A = 1,
h = 1,
f = 1,
v = "wifi",
O = 0;
function j(e) {
return Crypto.createHash("md5").update(e.toString()).digest("hex")
}
function k(e, t) {
return j(`client=${u}&mysticTime=${e}&product=${d}&key=${t}`)
}
function set_post_data(txt) {
const o = (new Date).getTime();
let e = 'fsdsogkndfokasodnaso'
return {
i: txt,
from: 'auto',
to: '',
dictResult: 'true',
keyid: 'webfanyi',
sign: k(o, e),
client: u,
product: d,
appVersion: p,
vendor: g,
pointParam: m,
mysticTime: o,
keyfrom: b,
mid: A,
screen: h,
model: f,
network: v,
abtest: O,
yduuid: "abcdefg"
}
}
3、使用python调用验证请求
[Python] 纯文本查看 复制代码 import requests
import execjs
cookies = {....}
headers = {
'Accept': 'application/json, text/plain, */*',
'Accept-Language': 'zh-CN,zh;q=0.9',
'Cache-Control': 'no-cache',
'Connection': 'keep-alive',
'Content-Type': 'application/x-www-form-urlencoded',
'Origin': 'https://fanyi.youdao.com',
'Pragma': 'no-cache',
'Referer': 'https://fanyi.youdao.com/',
'Sec-Fetch-Dest': 'empty',
'Sec-Fetch-Mode': 'cors',
'Sec-Fetch-Site': 'same-site',
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36',
'sec-ch-ua': '"Chromium";v="122", "Not(A:Brand";v="24", "Google Chrome";v="122"',
'sec-ch-ua-mobile': '?0',
'sec-ch-ua-platform': '"Windows"',
}
with open('./set_post_data.js', 'r', encoding='utf-8') as f:
set_post_data_code = f.read()
data = execjs.compile(set_post_data_code).call('set_post_data', txt)
response = requests.post('https://dict.youdao.com/webtranslate', headers=headers, cookies=cookies, data=data)
print(response.text)
三、数据解密
1、解密js分析
[JavaScript] 纯文本查看 复制代码 //解密分析
// c.a为crypto加密模块，直接导包替换就好
function y(e) {
return c.a.createHash("md5").update(e).digest()
}
R = (t,o,n)=>{
if (!t)
return null;
const a = e.alloc(16, y(o))
, i = e.alloc(16, y(n))
, r = c.a.createDecipheriv("aes-128-cbc", a, i);
let s = r.update(t, "base64", "utf-8");
return s += r.final("utf-8"),
s
}
// t为加密数据data
// o为key值
// n为iv值
// 固定值可写死
let o = "ydsecret://query/key/B*RGygVywfNBwpmBaZg*WT7SIOUP2T0C9WHMZN39j^DAdaZhAnxvGcCY6VYFwnHl";
// 固定值可写死
let n = "ydsecret://query/iv/C@lZe2YzHtZ2CYgaXKSVfsb7Y4QWHjITPPZ0nQp87fBeJ!Iv6v^6fvi2WN@bYpJ4";
2、整合封装代码
[Python] 纯文本查看 复制代码 const Crypto = require("crypto");
function y(e) {
// 使用 md5 算法创建一个哈希对象
return Crypto.createHash("md5")
// 更新哈希对象的内容为参数 e
.update(e)
// 获取哈希值并返回
.digest()
}
function get_data(data){
// 定义变量o，存储密钥
let o = "ydsecret://query/key/B*RGygVywfNBwpmBaZg*WT7SIOUP2T0C9WHMZN39j^DAdaZhAnxvGcCY6VYFwnHl";
// 定义变量n，存储初始化向量
let n = "ydsecret://query/iv/C@lZe2YzHtZ2CYgaXKSVfsb7Y4QWHjITPPZ0nQp87fBeJ!Iv6v^6fvi2WN@bYpJ4";
// 调用函数y，传入密钥o，将返回值赋给变量a
const a = y(o)
// 调用函数y，传入初始化向量n，将返回值赋给变量i
, i = y(n)
// 创建解密器r，使用AES-128-CBC算法，密钥为a，初始化向量为i
, r = Crypto.createDecipheriv("aes-128-cbc", a, i);
// 使用解密器r对传入的base64编码的数据data进行解密，结果以utf-8编码
let s = r.update(data, "base64", "utf-8");
// 将解密器r的最终结果以utf-8编码添加到s中，并返回s
return s += r.final("utf-8"),
s
}
3、整合代码使用python调用
[Python] 纯文本查看 复制代码 import requests
import execjs
import json
def youdao_translation(txt, headers, cookies):
try:
with open('./set_post_data.js', 'r', encoding='utf-8') as f:
set_post_data_code = f.read()
data = execjs.compile(set_post_data_code).call('set_post_data', txt)
response = requests.post('https://dict.youdao.com/webtranslate', headers=headers, cookies=cookies, data=data)
if response.status_code != 200:
raise Exception(f"无法获得翻译状态码: {response.status_code}")
with open('./get_data.js', 'r', encoding='utf-8') as f:
get_data_code = f.read()
result = execjs.compile(get_data_code).call('get_data', response.text)
print(json.loads(result)['translateResult'][0][0]['tgt'])
except FileNotFoundError:
print("没有找到一个所需的JS文件.")
except execjs.ProgramError:
print("日志含义执行JavaScript代码失败.")
except requests.RequestException:
print("建立网络失败")
if __name__ == '__main__':
cookies = {....}
headers = {
'Accept': 'application/json, text/plain, */*',
'Accept-Language': 'zh-CN,zh;q=0.9',
'Cache-Control': 'no-cache',
'Connection': 'keep-alive',
'Content-Type': 'application/x-www-form-urlencoded',
'Origin': 'https://fanyi.youdao.com',
'Pragma': 'no-cache',
'Referer': 'https://fanyi.youdao.com/',
'Sec-Fetch-Dest': 'empty',
'Sec-Fetch-Mode': 'cors',
'Sec-Fetch-Site': 'same-site',
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36',
'sec-ch-ua': '"Chromium";v="122", "Not(A:Brand";v="24", "Google Chrome";v="122"',
'sec-ch-ua-mobile': '?0',
'sec-ch-ua-platform': '"Windows"',
}
youdao_translation('你好', headers, cookies)
四、总结
1、接口分析获取加密参数生成
2、扣取代码，还原参数加密方法
3、调试分析加密数据生成逻辑，还原实现解密
声明：本文章仅供学习使用，上述代码请不要违规使用，所造成的一切不良后果与作者无关；如有侵权，请联系删除！！！
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