Python uses PyExecJS library to execute JS functions

Keywords: Python encoding Windows pip

                             . There are three solutions to this problem:

  • ① understand the encryption process of the front-end, and then write these methods (or find open source source code) with scripts to simulate the encryption process. The disadvantages are: if you don't understand JS, the cost of understanding is relatively high;
  • ②selenium + Chrome Headless. The disadvantages are: because it is a simulation click, the efficiency is lower than ① and ③;
  • ③ call JS engine with language to execute JS function. The disadvantages are: the execution effect of each JS engine will be inconsistent, resulting in some small deviations;

                              in the third way, python language can use three libraries: PyExecJS, PyV8, and. So this article mainly discusses the process of executing JS functions through PyExecJS Library of Python language (switching different JS engines).


PyExecJS official website case

pip installation:
pip install PyExecJS

Demo:

import execjs

print(execjs.eval("'red yellow blue'.split(' ')"))

ctx = execjs.compile("""
     function add(x, y) {
         return x + y;
     }
    """)
print(ctx.call("add", 1, 2))

Output:

['red', 'yellow', 'blue']
3


View JS engine information

# 1. You can run execjs without any other dependency on windows, because there is a JScript library by default. If you want to run other JS engine libraries, you need to install them separately.
   # JS environment of windows default execution
      execjs.get().name
      #Return value: JScript
   # If you want to switch, use os.environ ["execjs [runtime"] = "XXX". If you have just installed other JS engines, you must configure environment variables, and you may need to restart your computer or IDE.
   # If Node.js is installed on windows, you can switch nodes
      os.environ["EXECJS_RUNTIME"] = "Node"
      print(execjs.get().name)
      #Return value: Node.js (V8)
   # If phantom JS is installed on windows, you can switch phantom JS
      os.environ["EXECJS_RUNTIME"] = "PhantomJS"
      print(execjs.get().name)
      #Return value: PhantomJS
 
# 2. Under ubuntu, you need to install and execute JS environment dependency. The author's environment is phantom JS
      execjs.get().name
      #Return value: PhantomJS
 
# 3. The source code shows the environment in which execjs can be executed:
  PyV8           = "PyV8"
  Node           = "Node"
  JavaScriptCore = "JavaScriptCore"
  SpiderMonkey   = "SpiderMonkey"
  JScript        = "JScript"
  PhantomJS      = "PhantomJS"
  SlimerJS       = "SlimerJS"
  Nashorn        = "Nashorn"


Steps to install phantom JS

Download address:
http://phantomjs.org/download.html

Copy to your Python environment:
Unzip the downloaded file, find phantomjs.exe in the directory. \ phantomjs-2.1.1\bin \, and move it to the Script in the python folder.

# Example Anaconda3
D:\programfiles\Anaconda3\Scripts

Add system variable:
D:\programfiles\Anaconda3\Scriptsphantomjs.exe is added to the system variable.

verification:
After adding environment variables, verify in cmd that you can use the phantom JS command, indicating that the environment is set up.

Switch to PhantomJS in python:

os.environ["EXECJS_RUNTIME"] = "PhantomJS"


Case 1

1. Visit the login page of the target website and view the source code

   visit http://www.XXX.cn/login.html to see what js has done to the entered account and password before submitting the form. (pseudo code below)

<html>
<head></head>
<script src="http://www.XXX.cn/js/a.js"></script>
<script>
    function password(psw, code, acc) {
        return "[p]" + CryptoJS.e(CryptoJS.MD5(CryptoJS.MD5(CryptoJS.MD5(psw).toString() + code).toString()).toString() + "@" + acc, code);
    }
    
    function doencodeacc(acc, code) {
        alert("[p]" + CryptoJS.e(acc, code));
    }
    doencodeacc("zhansan123456","pYr6BTle");
</script>
<body>

</body>
    
</html>

2. Put js in the same directory as py script

   I paste the entire a.js file here for the convenience of students who need to experiment.

/*
CryptoJS v3.1.2
code.google.com/p/crypto-js
(c) 2009-2013 by Jeff Mott. All rights reserved.
code.google.com/p/crypto-js/wiki/License
*/
var CryptoJS=CryptoJS||function(u,p){var d={},l=d.lib={},s=function(){},t=l.Base={extend:function(a){s.prototype=this;var c=new s;a&&c.mixIn(a);c.hasOwnProperty("init")||(c.init=function(){c.$super.init.apply(this,arguments)});c.init.prototype=c;c.$super=this;return c},create:function(){var a=this.extend();a.init.apply(a,arguments);return a},init:function(){},mixIn:function(a){for(var c in a)a.hasOwnProperty(c)&&(this[c]=a[c]);a.hasOwnProperty("toString")&&(this.toString=a.toString)},clone:function(){return this.init.prototype.extend(this)}},
r=l.WordArray=t.extend({init:function(a,c){a=this.words=a||[];this.sigBytes=c!=p?c:4*a.length},toString:function(a){return(a||v).stringify(this)},concat:function(a){var c=this.words,e=a.words,j=this.sigBytes;a=a.sigBytes;this.clamp();if(j%4)for(var k=0;k<a;k++)c[j+k>>>2]|=(e[k>>>2]>>>24-8*(k%4)&255)<<24-8*((j+k)%4);else if(65535<e.length)for(k=0;k<a;k+=4)c[j+k>>>2]=e[k>>>2];else c.push.apply(c,e);this.sigBytes+=a;return this},clamp:function(){var a=this.words,c=this.sigBytes;a[c>>>2]&=4294967295<<
32-8*(c%4);a.length=u.ceil(c/4)},clone:function(){var a=t.clone.call(this);a.words=this.words.slice(0);return a},random:function(a){for(var c=[],e=0;e<a;e+=4)c.push(4294967296*u.random()|0);return new r.init(c,a)}}),w=d.enc={},v=w.Hex={stringify:function(a){var c=a.words;a=a.sigBytes;for(var e=[],j=0;j<a;j++){var k=c[j>>>2]>>>24-8*(j%4)&255;e.push((k>>>4).toString(16));e.push((k&15).toString(16))}return e.join("")},parse:function(a){for(var c=a.length,e=[],j=0;j<c;j+=2)e[j>>>3]|=parseInt(a.substr(j,
2),16)<<24-4*(j%8);return new r.init(e,c/2)}},b=w.Latin1={stringify:function(a){var c=a.words;a=a.sigBytes;for(var e=[],j=0;j<a;j++)e.push(String.fromCharCode(c[j>>>2]>>>24-8*(j%4)&255));return e.join("")},parse:function(a){for(var c=a.length,e=[],j=0;j<c;j++)e[j>>>2]|=(a.charCodeAt(j)&255)<<24-8*(j%4);return new r.init(e,c)}},x=w.Utf8={stringify:function(a){try{return decodeURIComponent(escape(b.stringify(a)))}catch(c){throw Error("Malformed UTF-8 data");}},parse:function(a){return b.parse(unescape(encodeURIComponent(a)))}},
q=l.BufferedBlockAlgorithm=t.extend({reset:function(){this._data=new r.init;this._nDataBytes=0},_append:function(a){"string"==typeof a&&(a=x.parse(a));this._data.concat(a);this._nDataBytes+=a.sigBytes},_process:function(a){var c=this._data,e=c.words,j=c.sigBytes,k=this.blockSize,b=j/(4*k),b=a?u.ceil(b):u.max((b|0)-this._minBufferSize,0);a=b*k;j=u.min(4*a,j);if(a){for(var q=0;q<a;q+=k)this._doProcessBlock(e,q);q=e.splice(0,a);c.sigBytes-=j}return new r.init(q,j)},clone:function(){var a=t.clone.call(this);
a._data=this._data.clone();return a},_minBufferSize:0});l.Hasher=q.extend({cfg:t.extend(),init:function(a){this.cfg=this.cfg.extend(a);this.reset()},reset:function(){q.reset.call(this);this._doReset()},update:function(a){this._append(a);this._process();return this},finalize:function(a){a&&this._append(a);return this._doFinalize()},blockSize:16,_createHelper:function(a){return function(b,e){return(new a.init(e)).finalize(b)}},_createHmacHelper:function(a){return function(b,e){return(new n.HMAC.init(a,
e)).finalize(b)}}});var n=d.algo={};return d}(Math);
(function(){var u=CryptoJS,p=u.lib.WordArray;u.enc.Base64={stringify:function(d){var l=d.words,p=d.sigBytes,t=this._map;d.clamp();d=[];for(var r=0;r<p;r+=3)for(var w=(l[r>>>2]>>>24-8*(r%4)&255)<<16|(l[r+1>>>2]>>>24-8*((r+1)%4)&255)<<8|l[r+2>>>2]>>>24-8*((r+2)%4)&255,v=0;4>v&&r+0.75*v<p;v++)d.push(t.charAt(w>>>6*(3-v)&63));if(l=t.charAt(64))for(;d.length%4;)d.push(l);return d.join("")},parse:function(d){var l=d.length,s=this._map,t=s.charAt(64);t&&(t=d.indexOf(t),-1!=t&&(l=t));for(var t=[],r=0,w=0;w<
l;w++)if(w%4){var v=s.indexOf(d.charAt(w-1))<<2*(w%4),b=s.indexOf(d.charAt(w))>>>6-2*(w%4);t[r>>>2]|=(v|b)<<24-8*(r%4);r++}return p.create(t,r)},_map:"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="}})();
(function(u){function p(b,n,a,c,e,j,k){b=b+(n&a|~n&c)+e+k;return(b<<j|b>>>32-j)+n}function d(b,n,a,c,e,j,k){b=b+(n&c|a&~c)+e+k;return(b<<j|b>>>32-j)+n}function l(b,n,a,c,e,j,k){b=b+(n^a^c)+e+k;return(b<<j|b>>>32-j)+n}function s(b,n,a,c,e,j,k){b=b+(a^(n|~c))+e+k;return(b<<j|b>>>32-j)+n}for(var t=CryptoJS,r=t.lib,w=r.WordArray,v=r.Hasher,r=t.algo,b=[],x=0;64>x;x++)b[x]=4294967296*u.abs(u.sin(x+1))|0;r=r.MD5=v.extend({_doReset:function(){this._hash=new w.init([1732584193,4023233417,2562383102,271733878])},
_doProcessBlock:function(q,n){for(var a=0;16>a;a++){var c=n+a,e=q[c];q[c]=(e<<8|e>>>24)&16711935|(e<<24|e>>>8)&4278255360}var a=this._hash.words,c=q[n+0],e=q[n+1],j=q[n+2],k=q[n+3],z=q[n+4],r=q[n+5],t=q[n+6],w=q[n+7],v=q[n+8],A=q[n+9],B=q[n+10],C=q[n+11],u=q[n+12],D=q[n+13],E=q[n+14],x=q[n+15],f=a[0],m=a[1],g=a[2],h=a[3],f=p(f,m,g,h,c,7,b[0]),h=p(h,f,m,g,e,12,b[1]),g=p(g,h,f,m,j,17,b[2]),m=p(m,g,h,f,k,22,b[3]),f=p(f,m,g,h,z,7,b[4]),h=p(h,f,m,g,r,12,b[5]),g=p(g,h,f,m,t,17,b[6]),m=p(m,g,h,f,w,22,b[7]),
f=p(f,m,g,h,v,7,b[8]),h=p(h,f,m,g,A,12,b[9]),g=p(g,h,f,m,B,17,b[10]),m=p(m,g,h,f,C,22,b[11]),f=p(f,m,g,h,u,7,b[12]),h=p(h,f,m,g,D,12,b[13]),g=p(g,h,f,m,E,17,b[14]),m=p(m,g,h,f,x,22,b[15]),f=d(f,m,g,h,e,5,b[16]),h=d(h,f,m,g,t,9,b[17]),g=d(g,h,f,m,C,14,b[18]),m=d(m,g,h,f,c,20,b[19]),f=d(f,m,g,h,r,5,b[20]),h=d(h,f,m,g,B,9,b[21]),g=d(g,h,f,m,x,14,b[22]),m=d(m,g,h,f,z,20,b[23]),f=d(f,m,g,h,A,5,b[24]),h=d(h,f,m,g,E,9,b[25]),g=d(g,h,f,m,k,14,b[26]),m=d(m,g,h,f,v,20,b[27]),f=d(f,m,g,h,D,5,b[28]),h=d(h,f,
m,g,j,9,b[29]),g=d(g,h,f,m,w,14,b[30]),m=d(m,g,h,f,u,20,b[31]),f=l(f,m,g,h,r,4,b[32]),h=l(h,f,m,g,v,11,b[33]),g=l(g,h,f,m,C,16,b[34]),m=l(m,g,h,f,E,23,b[35]),f=l(f,m,g,h,e,4,b[36]),h=l(h,f,m,g,z,11,b[37]),g=l(g,h,f,m,w,16,b[38]),m=l(m,g,h,f,B,23,b[39]),f=l(f,m,g,h,D,4,b[40]),h=l(h,f,m,g,c,11,b[41]),g=l(g,h,f,m,k,16,b[42]),m=l(m,g,h,f,t,23,b[43]),f=l(f,m,g,h,A,4,b[44]),h=l(h,f,m,g,u,11,b[45]),g=l(g,h,f,m,x,16,b[46]),m=l(m,g,h,f,j,23,b[47]),f=s(f,m,g,h,c,6,b[48]),h=s(h,f,m,g,w,10,b[49]),g=s(g,h,f,m,
E,15,b[50]),m=s(m,g,h,f,r,21,b[51]),f=s(f,m,g,h,u,6,b[52]),h=s(h,f,m,g,k,10,b[53]),g=s(g,h,f,m,B,15,b[54]),m=s(m,g,h,f,e,21,b[55]),f=s(f,m,g,h,v,6,b[56]),h=s(h,f,m,g,x,10,b[57]),g=s(g,h,f,m,t,15,b[58]),m=s(m,g,h,f,D,21,b[59]),f=s(f,m,g,h,z,6,b[60]),h=s(h,f,m,g,C,10,b[61]),g=s(g,h,f,m,j,15,b[62]),m=s(m,g,h,f,A,21,b[63]);a[0]=a[0]+f|0;a[1]=a[1]+m|0;a[2]=a[2]+g|0;a[3]=a[3]+h|0},_doFinalize:function(){var b=this._data,n=b.words,a=8*this._nDataBytes,c=8*b.sigBytes;n[c>>>5]|=128<<24-c%32;var e=u.floor(a/
4294967296);n[(c+64>>>9<<4)+15]=(e<<8|e>>>24)&16711935|(e<<24|e>>>8)&4278255360;n[(c+64>>>9<<4)+14]=(a<<8|a>>>24)&16711935|(a<<24|a>>>8)&4278255360;b.sigBytes=4*(n.length+1);this._process();b=this._hash;n=b.words;for(a=0;4>a;a++)c=n[a],n[a]=(c<<8|c>>>24)&16711935|(c<<24|c>>>8)&4278255360;return b},clone:function(){var b=v.clone.call(this);b._hash=this._hash.clone();return b}});t.MD5=v._createHelper(r);t.HmacMD5=v._createHmacHelper(r)})(Math);
(function(){var u=CryptoJS,p=u.lib,d=p.Base,l=p.WordArray,p=u.algo,s=p.EvpKDF=d.extend({cfg:d.extend({keySize:4,hasher:p.MD5,iterations:1}),init:function(d){this.cfg=this.cfg.extend(d)},compute:function(d,r){for(var p=this.cfg,s=p.hasher.create(),b=l.create(),u=b.words,q=p.keySize,p=p.iterations;u.length<q;){n&&s.update(n);var n=s.update(d).finalize(r);s.reset();for(var a=1;a<p;a++)n=s.finalize(n),s.reset();b.concat(n)}b.sigBytes=4*q;return b}});u.EvpKDF=function(d,l,p){return s.create(p).compute(d,
l)}})();
CryptoJS.lib.Cipher||function(u){var p=CryptoJS,d=p.lib,l=d.Base,s=d.WordArray,t=d.BufferedBlockAlgorithm,r=p.enc.Base64,w=p.algo.EvpKDF,v=d.Cipher=t.extend({cfg:l.extend(),createEncryptor:function(e,a){return this.create(this._ENC_XFORM_MODE,e,a)},createDecryptor:function(e,a){return this.create(this._DEC_XFORM_MODE,e,a)},init:function(e,a,b){this.cfg=this.cfg.extend(b);this._xformMode=e;this._key=a;this.reset()},reset:function(){t.reset.call(this);this._doReset()},process:function(e){this._append(e);return this._process()},
finalize:function(e){e&&this._append(e);return this._doFinalize()},keySize:4,ivSize:4,_ENC_XFORM_MODE:1,_DEC_XFORM_MODE:2,_createHelper:function(e){return{encrypt:function(b,k,d){return("string"==typeof k?c:a).encrypt(e,b,k,d)},decrypt:function(b,k,d){return("string"==typeof k?c:a).decrypt(e,b,k,d)}}}});d.StreamCipher=v.extend({_doFinalize:function(){return this._process(!0)},blockSize:1});var b=p.mode={},x=function(e,a,b){var c=this._iv;c?this._iv=u:c=this._prevBlock;for(var d=0;d<b;d++)e[a+d]^=
c[d]},q=(d.BlockCipherMode=l.extend({createEncryptor:function(e,a){return this.Encryptor.create(e,a)},createDecryptor:function(e,a){return this.Decryptor.create(e,a)},init:function(e,a){this._cipher=e;this._iv=a}})).extend();q.Encryptor=q.extend({processBlock:function(e,a){var b=this._cipher,c=b.blockSize;x.call(this,e,a,c);b.encryptBlock(e,a);this._prevBlock=e.slice(a,a+c)}});q.Decryptor=q.extend({processBlock:function(e,a){var b=this._cipher,c=b.blockSize,d=e.slice(a,a+c);b.decryptBlock(e,a);x.call(this,
e,a,c);this._prevBlock=d}});b=b.CBC=q;q=(p.pad={}).Pkcs7={pad:function(a,b){for(var c=4*b,c=c-a.sigBytes%c,d=c<<24|c<<16|c<<8|c,l=[],n=0;n<c;n+=4)l.push(d);c=s.create(l,c);a.concat(c)},unpad:function(a){a.sigBytes-=a.words[a.sigBytes-1>>>2]&255}};d.BlockCipher=v.extend({cfg:v.cfg.extend({mode:b,padding:q}),reset:function(){v.reset.call(this);var a=this.cfg,b=a.iv,a=a.mode;if(this._xformMode==this._ENC_XFORM_MODE)var c=a.createEncryptor;else c=a.createDecryptor,this._minBufferSize=1;this._mode=c.call(a,
this,b&&b.words)},_doProcessBlock:function(a,b){this._mode.processBlock(a,b)},_doFinalize:function(){var a=this.cfg.padding;if(this._xformMode==this._ENC_XFORM_MODE){a.pad(this._data,this.blockSize);var b=this._process(!0)}else b=this._process(!0),a.unpad(b);return b},blockSize:4});var n=d.CipherParams=l.extend({init:function(a){this.mixIn(a)},toString:function(a){return(a||this.formatter).stringify(this)}}),b=(p.format={}).OpenSSL={stringify:function(a){var b=a.ciphertext;a=a.salt;return(a?s.create([1398893684,
1701076831]).concat(a).concat(b):b).toString(r)},parse:function(a){a=r.parse(a);var b=a.words;if(1398893684==b[0]&&1701076831==b[1]){var c=s.create(b.slice(2,4));b.splice(0,4);a.sigBytes-=16}return n.create({ciphertext:a,salt:c})}},a=d.SerializableCipher=l.extend({cfg:l.extend({format:b}),encrypt:function(a,b,c,d){d=this.cfg.extend(d);var l=a.createEncryptor(c,d);b=l.finalize(b);l=l.cfg;return n.create({ciphertext:b,key:c,iv:l.iv,algorithm:a,mode:l.mode,padding:l.padding,blockSize:a.blockSize,formatter:d.format})},
decrypt:function(a,b,c,d){d=this.cfg.extend(d);b=this._parse(b,d.format);return a.createDecryptor(c,d).finalize(b.ciphertext)},_parse:function(a,b){return"string"==typeof a?b.parse(a,this):a}}),p=(p.kdf={}).OpenSSL={execute:function(a,b,c,d){d||(d=s.random(8));a=w.create({keySize:b+c}).compute(a,d);c=s.create(a.words.slice(b),4*c);a.sigBytes=4*b;return n.create({key:a,iv:c,salt:d})}},c=d.PasswordBasedCipher=a.extend({cfg:a.cfg.extend({kdf:p}),encrypt:function(b,c,d,l){l=this.cfg.extend(l);d=l.kdf.execute(d,
b.keySize,b.ivSize);l.iv=d.iv;b=a.encrypt.call(this,b,c,d.key,l);b.mixIn(d);return b},decrypt:function(b,c,d,l){l=this.cfg.extend(l);c=this._parse(c,l.format);d=l.kdf.execute(d,b.keySize,b.ivSize,c.salt);l.iv=d.iv;return a.decrypt.call(this,b,c,d.key,l)}})}();
(function(){for(var u=CryptoJS,p=u.lib.BlockCipher,d=u.algo,l=[],s=[],t=[],r=[],w=[],v=[],b=[],x=[],q=[],n=[],a=[],c=0;256>c;c++)a[c]=128>c?c<<1:c<<1^283;for(var e=0,j=0,c=0;256>c;c++){var k=j^j<<1^j<<2^j<<3^j<<4,k=k>>>8^k&255^99;l[e]=k;s[k]=e;var z=a[e],F=a[z],G=a[F],y=257*a[k]^16843008*k;t[e]=y<<24|y>>>8;r[e]=y<<16|y>>>16;w[e]=y<<8|y>>>24;v[e]=y;y=16843009*G^65537*F^257*z^16843008*e;b[k]=y<<24|y>>>8;x[k]=y<<16|y>>>16;q[k]=y<<8|y>>>24;n[k]=y;e?(e=z^a[a[a[G^z]]],j^=a[a[j]]):e=j=1}var H=[0,1,2,4,8,
16,32,64,128,27,54],d=d.AES=p.extend({_doReset:function(){for(var a=this._key,c=a.words,d=a.sigBytes/4,a=4*((this._nRounds=d+6)+1),e=this._keySchedule=[],j=0;j<a;j++)if(j<d)e[j]=c[j];else{var k=e[j-1];j%d?6<d&&4==j%d&&(k=l[k>>>24]<<24|l[k>>>16&255]<<16|l[k>>>8&255]<<8|l[k&255]):(k=k<<8|k>>>24,k=l[k>>>24]<<24|l[k>>>16&255]<<16|l[k>>>8&255]<<8|l[k&255],k^=H[j/d|0]<<24);e[j]=e[j-d]^k}c=this._invKeySchedule=[];for(d=0;d<a;d++)j=a-d,k=d%4?e[j]:e[j-4],c[d]=4>d||4>=j?k:b[l[k>>>24]]^x[l[k>>>16&255]]^q[l[k>>>
8&255]]^n[l[k&255]]},encryptBlock:function(a,b){this._doCryptBlock(a,b,this._keySchedule,t,r,w,v,l)},decryptBlock:function(a,c){var d=a[c+1];a[c+1]=a[c+3];a[c+3]=d;this._doCryptBlock(a,c,this._invKeySchedule,b,x,q,n,s);d=a[c+1];a[c+1]=a[c+3];a[c+3]=d},_doCryptBlock:function(a,b,c,d,e,j,l,f){for(var m=this._nRounds,g=a[b]^c[0],h=a[b+1]^c[1],k=a[b+2]^c[2],n=a[b+3]^c[3],p=4,r=1;r<m;r++)var q=d[g>>>24]^e[h>>>16&255]^j[k>>>8&255]^l[n&255]^c[p++],s=d[h>>>24]^e[k>>>16&255]^j[n>>>8&255]^l[g&255]^c[p++],t=
d[k>>>24]^e[n>>>16&255]^j[g>>>8&255]^l[h&255]^c[p++],n=d[n>>>24]^e[g>>>16&255]^j[h>>>8&255]^l[k&255]^c[p++],g=q,h=s,k=t;q=(f[g>>>24]<<24|f[h>>>16&255]<<16|f[k>>>8&255]<<8|f[n&255])^c[p++];s=(f[h>>>24]<<24|f[k>>>16&255]<<16|f[n>>>8&255]<<8|f[g&255])^c[p++];t=(f[k>>>24]<<24|f[n>>>16&255]<<16|f[g>>>8&255]<<8|f[h&255])^c[p++];n=(f[n>>>24]<<24|f[g>>>16&255]<<16|f[h>>>8&255]<<8|f[k&255])^c[p++];a[b]=q;a[b+1]=s;a[b+2]=t;a[b+3]=n},keySize:8});u.AES=p._createHelper(d)})();function _k(h){var e=h+"0123456789abcdef";return e.substring(0, 16);}
CryptoJS.e = function (d,p) {
    var key = CryptoJS.enc.Utf8.parse(_k(p));
    var encrypted = CryptoJS.AES.encrypt(d, key, {
        iv: key,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.Pkcs7
    });
    return encrypted.toString();
};

function doencodepsw(psw, code, acc) {
            return "[p]" + CryptoJS.e(CryptoJS.MD5(CryptoJS.MD5(CryptoJS.MD5(psw).toString() + code).toString()).toString() + "@" + acc, code);
}

function doencodeacc(acc, code) {
    return "[p]" + CryptoJS.e(acc, code);
}

3. Write Python script to call js

import execjs

def get_js():
    # Open JS file
    f = open("C:/testjs.js", 'r', encoding='utf-8')
    line = f.readline()
    htmlstr = ''
    while line:
        htmlstr = htmlstr + line
        line = f.readline()
    return htmlstr

def get_des_psswd(acc, code):
    jsstr = get_js()
    #  Load JS file
    ctx = execjs.compile(jsstr)
    # The first parameter to call JS method is JS method name, followed by JS method parameter
    return ctx.call('doencodeacc', acc, code)

if __name__ == '__main__': 
    print(get_des_psswd("zhangsan123456", "pYr6BTle"))   # pYr6BTle = ralt code (encrypted salt value)


Case 2

This case is relatively complicated;

1. Find the encryption function at login

Contract awarding


                      . It is recommended to use Chrome F12 for debugging. Other tools are not as easy to use.

Right click to check the source code. JS is found, but there are too many. Filter it.

2. Listen to the mouse click event viewing process


After an operation, skip to the login and submit function and look at the code directly

Looking down at the code, I find that the code is not confused and there is no other protection. That's a one-step solution. Cracking the encryption is not as simple as cutting vegetables.

3. Write code

Import js:
Import jsencrypt.js into the python project. This JS has more than 5000 lines, so I won't paste it.

import execjs
import os

if __name__ == '__main__':
    # After switching JScript and Node, JS cannot be executed. It is found that phantom JS is reliable
    # os.environ["EXECJS_RUNTIME"] = "JScript"
    # os.environ["EXECJS_RUNTIME"] = "Node"
    os.environ["EXECJS_RUNTIME"] = "PhantomJS"
    print(execjs.get().name)

    js = open('jsencrypt.js', encoding='utf-8').read()
    jo = execjs.compile(js)
    pwd = jo.call('myf')
    print(pwd)

Output:

PhantomJS
Hu4Ujwqwe/PDAblIvjNyrX4NrltoRXXDdyC6+F+p0LaqPSegMZ16oIqeVPiHlh5x8zKeI2DC3DoPVf8ZlusUCQ==


Different versions of browser kernel handle URL encoding differently [cold knowledge]

   when Html's form is submitted, the parameters of each form will be Url encoded before being sent. For historical reasons, the Url encoded implementation used by the form does not meet the latest standards. For example, the encoding used for space is not% 20, but the + sign. If the form is submitted by Post method, we can see a content type header in the HTTP header, with the value of application/x-www-form-urlencoded. Most applications can deal with this non-standard implementation of Url encoding, but in client-side Javascript, there is no function that can decode the + sign into a space and only write its own conversion function. Also, for non ASCII characters, the encoded character set used depends on the character set used in the current document.

Reference article

  • https://pypi.org/project/PyExecJS
  • https://blog.csdn.net/xc_zhou/article/details/80952155
  • https://www.cnblogs.com/jerrysion/p/5522673.html

Posted by christophe on Tue, 17 Dec 2019 04:04:37 -0800

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