JavaScript奇技淫巧:执行“二进制”代码

如果将JavaScript代码转化成能执行的二进制字符串，是不是很有意思呢？起码看起来会很酷，运行效果如下图：

在图中，可以看到二进制字符串被执行，并输出了结果。

这是如何实现的呢？

先看这段执行的代码：

const result = executeBinary("0000101001100110011101010110111001100011011101000110100101101111011011100010000001100111011001010111010001011111011000110110111101110000011110010111001001101001011001110110100001110100001010000010100101111011000010100010000000100000001000000010000001110110011000010111001000100000011001000110111101101101011000010110100101101110001000000011110100100000001000100110101001110011011010000110000101101101011000010110111000101110011000110110111101101101001000100011101100001010001000000010000000100000001000000111011001100001011100100010000001100110011100100110111101101101010111110111100101100101011000010111001000100000001111010010000000110010001100000011000100110111001110110000101000100000001000000010000000100000011101100110000101110010001000000110001101101111011100000111100101110010011010010110011101101000011101000010000000111101001000000010001000101000011000110010100100100010001000000010101100100000011001100111001001101111011011010101111101111001011001010110000101110010001000000010101100100000001000100010110100100010001000000010101100100000001010000110111001100101011101110010000001000100011000010111010001100101001010010010111001100111011001010111010001000110011101010110110001101100010110010110010101100001011100100010100000101001001000000010101100100000001000100010110000100010001000000010101100100000011001000110111101101101011000010110100101101110001110110000101000100000001000000010000000100000011100100110010101110100011101010111001001101110001000000110001101101111011100000111100101110010011010010110011101101000011101000011101100001010011111010000101001100011011011110110111001110011011011110110110001100101001011100110110001101111011001110010100001100111011001010111010001011111011000110110111101110000011110010111001001101001011001110110100001110100001010000010100100101001001110110000101000001010");

// 执行二进制字符串
function executeBinary(binary) {
console.log("二进制字符串：",binary);
// 将二进制字符串按每 8 位截断，并将其转换成字节数组
const bytes = binary.match(/.{8}/g).map((byte) => parseInt(byte, 2));
// 创建 ArrayBuffer
const buffer = new ArrayBuffer(bytes.length);
// 将字节数组写入 ArrayBuffer 中
const uint8Array = new Uint8Array(buffer);
bytes.forEach((byte, index) => (uint8Array[index] = byte));
// 使用 TextDecoder 解码 ArrayBuffer 中的内容
const code = new TextDecoder().decode(buffer);
console.log("执行结果：");
// 执行还原后的 JS 代码
return (new Function(code))();
}

由代码可知，这确实是一段二进制字符，但显然二进制是不能直接执行的，它是由正常代码编码而成的，执行前，先需将二进制转化为原始代码。然后，用new Function的方式转成立即执行函数并运行。相当于是一种看起来比较绚丽的加密算法。

但就代码形式而言，执行函数相对于0101的二进制形式太异类，因此，我们可以将上面的executeBinary函数代码用JShaman进行混淆加密，使它变的不那么正规，使整体代码看起来都很怪异。如下图：

而二进制字符串的得来也比较简单，代码如下：

// 示例 JS 代码
const jsCode = `
function get_copyright(){
    var domain = "jshaman.com";
    var from_year = 2017;
    var copyright = "(c)" + from_year + "-" + (new Date).getFullYear() + "," + domain;
    return copyright;
}
console.log(get_copyright());
`;
// 将 JS 代码转换为二进制字符串
function convertToBinary(code) {
    let binary = "";
    for (let i = 0; i < code.length; i++) {
        const charCode = code.charCodeAt(i);
        const charBinary = charCode.toString(2).padStart(8, "0");
        binary += charBinary;
    }
    return binary;
}
const binaryCode = convertToBinary(jsCode);
// 输出二进制字符串
console.log(binaryCode);

即：将JS代码做为字符串，转换成二进制形式。