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

淡淡的烟草味﹌ 2023-01-09 04:00 204阅读 0赞

## 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