前端JavaScript代码混淆加密原理简单示例及介绍

// 没有代码混淆
var username = "user123";
var password = "pass456";

function login(user, pass) {
  if (user === username && pass === password) {
    console.log("Login successful!");
  } else {
    console.log("Login failed!");
  }
}

login(username, password);

// 使用变量名混淆进行代码混淆
var a = "user123";
var b = "pass456";

function c(d, e) {
  if (d === a && e === b) {
    console.log("Login successful!");
  } else {
    console.log("Login failed!");
  }
}

c(a, b);

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// 没有代码混淆
function add(x, y) {
  return x + y;
}

console.log(add(2, 3));

// 使用函数名混淆进行代码混淆
var a = function(b, c) {
  return b + c;
}

console.log(a(2, 3));

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function calculateSum(num1, num2) {
  var sum = num1 + num2;
  return sum;
}

var result = calculateSum(3, 4);
console.log(result);

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function calculateSum(a,b){return a+b}console.log(calculateSum(3,4));

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//文本编码为base64
const text = "Hello, world!";
const base64 = btoa(text);
console.log(base64); // 输出 "SGVsbG8sIHdvcmxkIQ=="

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//base64解码为文本
const base64 = "SGVsbG8sIHdvcmxkIQ==";
const text = atob(base64);
console.log(text); // 输出 "Hello, world!"

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var message = "Hello World!";
alert(message);

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var _0x3d9d=["x48x65x6Cx6Cx6Fx20x57x6Fx72x6Cx64x21"];alert(_0x3d9d[0]);

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const a = 1;
const b = 2;
let c = 0;
if (a === 1) {
  if (b === 2) {
    c = 3;
  }
} else {
  c = 4;
}

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const a = 1;
const b = 2;
let c = 0;
if (!(a !== 1)) {
  if (!(![])) c = 3;
} else {
  if (!(!{})) c = 4;
}

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// 变量重命名示例
const esprima = require('esprima');
const estraverse = require('estraverse');

const code = `
  function add(a, b) {
    let c = a + b;
    return c;
  }
`;

const ast = esprima.parseScript(code);

const varMap = {
  'a': 'x',
  'b': 'y',
  'c': 'z'
};

estraverse.replace(ast, {
  enter(node) {
    if (node.type === 'Identifier' && varMap[node.name]) {
      node.name = varMap[node.name];
    }
  }
});

const newCode = escodegen.generate(ast);

console.log(newCode);

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// 将加号替换成减号
const code = `
  const sum = (a, b) => a + b;
  const result = sum(1, 2);
`;

const ast = esprima.parseScript(code);
const newAst = replaceCode(ast, "+", "-");

console.log(generate(newAst));

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//babel实现将代码中的所有值为false的节点并替换为![]
const parser = require("@babel/parser");
const traverse = require("@babel/traverse").default;
const generator = require("@babel/generator").default;

// 原始代码
const code = `let flag = false;
if (flag) {
  console.log("Flag is true");
} else {
  console.log("Flag is false");
}`;

const ast = parser.parse(code);

traverse(ast, {
  enter(path) {
    if (path.isBooleanLiteral({ value: false })) {
      path.replaceWith(parser.parse("![]").program.body[0].expression);
    }
  }
});

// 将AST语法树重新生成为代码字符串
const newCode = generator(ast).code;

// 输出新代码
console.log(newCode);

// 新代码为:
// let flag = ![];
// if (flag) {
//   console.log("Flag is true");
// } else {
//   console.log("Flag is ![]");
// }

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