HOOK逆向

目录

• document.cookie
  • 常见做法
  • 较好的hook做法
• hook函数
• hook方法
• new Proxy加with
• hook xhr请求
• ast注入hook函数

document.cookie

常见做法

var oldCookie = document.cookie;
Object.defineProperty(document, "cookie", {
   get(){
       return oldCookie;
   },
   set(val){
       console.log("setting cookie", val);
       oldCookie += ";" +val;
   }

})

这样做法有两个问题，其一是cookie并没有被设置上，只是js 获取与设置cookie的时候可以hook到。

其二是需要自己处理设置cookie的情况，比如更新，删除cookie。

返回目录

较好的hook做法

// 代码来源 https://stackoverflow.com/questions/32410331/proxying-of-document-cookie
var cookieDesc = Object.getOwnPropertyDescriptor(Document.prototype, 'cookie') ||
                 Object.getOwnPropertyDescriptor(HTMLDocument.prototype, 'cookie');
if (cookieDesc && cookieDesc.configurable) {
    Object.defineProperty(document, 'cookie', {
        get: function () {
            return cookieDesc.get.call(document);
        },
        set: function (val) {
            console.log(val);
            cookieDesc.set.call(document, val);
        }
    });
}

hook函数

var oldEval = eval;
eval = function(){
    console.log("exec", arguments[0]);
    return oldEval.apply(this, arguments);
}

返回目录

hook方法

var obj = {
  a: {
  }  
};

var old = obj.a;

Object.defineProperty(obj, "a", {
   get(){
     return old;
  },
   set(val){
     console.log("obj.a set to be", val);
     old = val;
     return old
   }
})
obj.a = 111;

new Proxy加with

 const handlers = {
        get(target, p, rev) {
            const result = Reflect.get(target, p);
            console.log(`reading ${target.constructor.name}.${p}, value=${result}`)
            return result;
        },
        set(tagret, p, value, rev) {
            const result = Reflect.set(tagret, p, value);
            console.log(`setting ${target}.${p} = ${value}`);
            return result;
        }
    };
    (function setHook() {
        const withObject = { window: {} };
        const mappedObject = {
            location, navigator, document
        };
        Object.keys(mappedObject).forEach((key) => {
            var proxiedMethod = new Proxy(mappedObject[key], handlers);
            withObject[key] = proxiedMethod;
        });
        withObject.window = withObject;
        window.withObject = withObject;
    })();

    with (withObject) {
        console.log(window.a);
        console.log(navigator.userAgent);
        console.log(location.href);
    }

hook xhr请求

ast注入hook函数

利用ast给所有的赋值语句加上一层包装

var obj = {
  a: {}  
};

console.log(obj.a); // 读取
obj.a = 11;            // 设置



// 包装成这样

console.log(wrapper(obj.a, obj, "a", {type: "property access"}));
wrapper(obj.a, obj, "a", {type: "property assignment", value: 11});