JavaScript 代码混淆实战(六):仿obfuscator混淆控制流平坦化

混淆前:

       window = {};
       window.atob = function(r) {
        e = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
       var o = String(r).replace(/=+$/, "");
       if(o.length % 4 == 1) throw new t("'atob' failed: The string to be decoded is not correctly encoded.");
       for(var n, a, i = 0, c = 0, d = ""; a = o.charAt(c++); ~a && (n = i % 4 ? 64 * n + a : a, i++ % 4) ? d += String.fromCharCode(255 & n >> (-2 * i & 6)) : 0) a = e.indexOf(a);
       return d
       }
       window.btoa = function(r) {
        e = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
       for(var o, n, a = String(r), i = 0, c = e, d = ""; a.charAt(0 | i) || (c = "=", i % 1); d += c.charAt(63 & o >> 8 - i % 1 * 8)) {
       if(n = a.charCodeAt(i += .75), n > 255) throw new t("'btoa' failed: The string to be encoded contains characters outside of the Latin1 range.");
        o = o << 8 | n
        }
       return d
       }
   
  

混淆后:

       window = {};
       window.atob = function (_0xc0750g) {
        var _0xfbb16d = "4|1|2|3|0"["split"]("|"),
        _0xec2868 = 0;
        while (!![]) {
       switch (_0xfbb16d[_0xec2868++]) {
       case "0":
       return _0xec4345;
       continue;
       case "1":
       var _0x1adc16 = String(_0xc0750g).replace(/=+$/, "");
       continue;
       case "2":
       if (_0x1adc16.length % 4 == 1) throw new t("'atob' failed: The string to be decoded is not correctly encoded.");
       continue;
       case "3":
       for (var _0xb342a5, _0x7ecb47, _0xc54a87 = 0, _0xa14d1g = 0, _0xec4345 = ""; _0x7ecb47 = _0x1adc16.charAt(_0xa14d1g++); ~_0x7ecb47 && (_0xb342a5 = _0xc54a87 % 4 ? 64 * _0xb342a5 + _0x7ecb47 : _0x7ecb47, _0xc54a87++ % 4) ? _0xec4345 += String.fromCharCode(255 & _0xb342a5 >> (-2 * _0xc54a87 & 6)) : 0) _0x7ecb47 = e.indexOf(_0x7ecb47);
       continue;
       case "4":
        e = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
       continue;
        }
       break;
         }
       };
       window.btoa = function (_0xdc05f0) {
        var _0x39674c = "2|1|0"["split"]("|"),
        _0x902bcb = 0;
        while (!![]) {
       switch (_0x39674c[_0x902bcb++]) {
       case "0":
       return _0xde212b;
       continue;
       case "1":
       for (var _0xed1fcd, _0x33g15b, _0x5153cd = String(_0xdc05f0), _0xeea791 = 0, _0xc94d67 = e, _0xde212b = ""; _0x5153cd.charAt(0 | _0xeea791) || (_0xc94d67 = "=", _0xeea791 % 1); _0xde212b += _0xc94d67.charAt(63 & _0xed1fcd >> 8 - _0xeea791 % 1 * 8)) {
       var _0xcgcd3c = "0|1"["split"]("|"),
        _0x3922ce = 0;
       while (!![]) {
       switch (_0xcgcd3c[_0x3922ce++]) {
       case "0":
       if (_0x33g15b = _0x5153cd.charCodeAt(_0xeea791 += .75), _0x33g15b > 255) throw new t("'btoa' failed: The string to be encoded contains characters outside of the Latin1 range.");
       continue;
       case "1":
        _0xed1fcd = _0xed1fcd << 8 | _0x33g15b;
       continue;
        }
       break;
        }
        }
       continue;
       case "2":
        e = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
       continue;
        }
       break;
         }
       };
   
  

混淆后的代码，就是我们常见的obfuscator混淆代码。

源代码见github地址:

https://github.com/Tsaiboss/ControlFlow