Reptile learning 4 winter vacation series (3)

Online cloud suppression hot reviews crawl

These two parameters are encrypted , Our task is to simulate the encryption process of Netease cloud , Encryption parameters are passed to the browser .

1） New tools ,call stack Called stack , That is, when I send a request to the file on the left , What are they? js Script execution process , Arranged from bottom to top
2） To set breakpoints , View parameter and variable values
3） Learn to simulate website rendering process through stack
4） Learn to simplify the process of website encryption
Judge whether the parameters can be fixed , If it can be fixed , You can get relevant parameters from the web page , Minimize random parameters .

What we need to do now is to figure out how the program is encrypted .
Out of line
It's too complicated
Don't look at the lack of code , But it's complicated , What is involved . Code is the essence , By fixing parameters , Encrypt the final required parameters ; But finding and implementing this encryption process is very strong . I was confused about this project , Take a break .
It's impossible to estimate the probability just by looking at the code and notes , A face of meng , Of course, we should exclude the great gods
#pycrypto Module is to provide encryption algorithm
#base64 Modules are used to convert to bytes , Give Way utf-8 It can be recognized
#json The module is transformed into json String in
The following is the encryption rules obtained from the website following the process , Our task is to understand the principle of encryption , Then we restore the encryption process , The simplification of the tutorial is too strong .

#  The encryption process （ The encryption algorithm on the intercepted website ）
    function a(a=16) {
     #  Back to c Is random 16 A string 
        var d, e, b = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", c = "";
        for (d = 0; a > d; d += 1)#  loop 16 Time 
            e = Math.random() * b.length,#  random number 
            e = Math.floor(e),#  integer 
            c += b.charAt(e);#  Take the string xxx Location 
        return c
    }
    function b(a, b) {
     # a Is the content to be encrypted ,
        var c = CryptoJS.enc.Utf8.parse(b) # c yes b, therefore b It's the key 
          , d = CryptoJS.enc.Utf8.parse("0102030405060708")
          , e = CryptoJS.enc.Utf8.parse(a) # e Is the data 
          , f = CryptoJS.AES.encrypt(e, c, {
     #  One key is missing ,c It's an encrypted key 
            iv: d,  #  Offset 
            mode: CryptoJS.mode.CBC #  Encryption mode CBC
        });
        return f.toString()
    }
    function c(a, b, c) {
    
        var d, e;
        return setMaxDigits(131),
        d = new RSAKeyPair(b,"",c),
        e = encryptedString(d, a)
    }
    function d(d, e, f, g) {
      d: data data,  e:010001,  f: Very long fixed value ,  g:0CoJUm6Qyw8W8jud
        var h = {
    } #  An empty object 
          , i = a(16); # i yes 16 Random values of bits 
        return h.encText = b(d, g), # g It's the key 
        h.encText = b(h.encText, i), #  Back to you params,i It's also a key 
        h.encSecKey = c(i, e, f), #  What you get is encSecKey, So both parameters are obtained 
        #  hold i Hold on , Then the generated parameter is also a fixed value , because i e f Only i Random number , And c() No random numbers 
        h
        #  These four sentences are return h, Need to see b() and c()
    }

I've seen that the subsequent operation is to clean the crawled information , Then sort out the key hot words , Form hot word posters .