某汽车交易网站数据抓取

aHR0cHM6Ly93d3cuZ3VhemkuY29tLw==

分析请求

打开首页，查看获取 热卖车型 的请求

发现就是一个很简单的 get 请求，也没有什么加密参数，但是当直接访问时就发现并没有返回想要的结果，而是跳转到了首页，说明需要对header做分析了，调了一圈发现是 antipas 这个cookie 的问题

全局搜索后也没有发现设置的请求，那就从第一个请求找起，结果发现从第二个请求就开始有这个cookie了，但是第一个203请求在chrome中看不到响应内容，所以使用fiddler抓包分析，果然看到了内容

发现这是一段eval执行的js代码，在浏览器新建一个窗口，把粘贴到控制台

发现 value 就是我们要找的结果，是通过 anti 这个函数调用返回的，看下这个函数

好了，把还原后的代码在本地执行，缺什么补什么，最后结果是这样的

window = {location: {}}

function safeAdd(x, y) {
    var lsw = (x & 0xFFFF) + (y & 0xFFFF);
    var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
    return (msw << 16) | (lsw & 0xFFFF)
}
function bitRotateLeft(num, cnt) {
    return (num << cnt) | (num >>> (32 - cnt))
}
function cmn(q, a, b, x, s, t) {
    return safeAdd(bitRotateLeft(safeAdd(safeAdd(a, q), safeAdd(x, t)), s), b)
}
function ff(a, b, c, d, x, s, t) {
    return cmn((b & c) | ((~b) & d), a, b, x, s, t)
}
function gg(a, b, c, d, x, s, t) {
    return cmn((b & d) | (c & (~d)), a, b, x, s, t)
}
function hh(a, b, c, d, x, s, t) {
    return cmn(b ^ c ^ d, a, b, x, s, t)
}
function ii(a, b, c, d, x, s, t) {
    return cmn(c ^ (b | (~d)), a, b, x, s, t)
}
function binl(x, len) {
    x[len >> 5] |= 0x80 << (len % 32);
    x[(((len + 64) >>> 9) << 4) + 14] = len;
    var i;
    var olda;
    var oldb;
    var oldc;
    var oldd;
    var a = 1732584193;
    var b = -271733879;
    var c = -1732584194;
    var d = 271733878;
    for (i = 0; i < x.length; i += 16) {
        olda = a;
        oldb = b;
        oldc = c;
        oldd = d;
        a = ff(a, b, c, d, x[i], 7, -680876936);
        d = ff(d, a, b, c, x[i + 1], 12, -389564586);
        c = ff(c, d, a, b, x[i + 2], 17, 606105819);
        b = ff(b, c, d, a, x[i + 3], 22, -1044525330);
        a = ff(a, b, c, d, x[i + 4], 7, -176418897);
        d = ff(d, a, b, c, x[i + 5], 12, 1200080426);
        c = ff(c, d, a, b, x[i + 6], 17, -1473231341);
        b = ff(b, c, d, a, x[i + 7], 22, -45705983);
        a = ff(a, b, c, d, x[i + 8], 7, 1770035416);
        d = ff(d, a, b, c, x[i + 9], 12, -1958414417);
        c = ff(c, d, a, b, x[i + 10], 17, -42063);
        b = ff(b, c, d, a, x[i + 11], 22, -1990404162);
        a = ff(a, b, c, d, x[i + 12], 7, 1804603682);
        d = ff(d, a, b, c, x[i + 13], 12, -40341101);
        c = ff(c, d, a, b, x[i + 14], 17, -1502002290);
        b = ff(b, c, d, a, x[i + 15], 22, 1236535329);
        a = gg(a, b, c, d, x[i + 1], 5, -165796510);
        d = gg(d, a, b, c, x[i + 6], 9, -1069501632);
        c = gg(c, d, a, b, x[i + 11], 14, 643717713);
        b = gg(b, c, d, a, x[i], 20, -373897302);
        a = gg(a, b, c, d, x[i + 5], 5, -701558691);
        d = gg(d, a, b, c, x[i + 10], 9, 38016083);
        c = gg(c, d, a, b, x[i + 15], 14, -660478335);
        b = gg(b, c, d, a, x[i + 4], 20, -405537848);
        a = gg(a, b, c, d, x[i + 9], 5, 568446438);
        d = gg(d, a, b, c, x[i + 14], 9, -1019803690);
        c = gg(c, d, a, b, x[i + 3], 14, -187363961);
        b = gg(b, c, d, a, x[i + 8], 20, 1163531501);
        a = gg(a, b, c, d, x[i + 13], 5, -1444681467);
        d = gg(d, a, b, c, x[i + 2], 9, -51403784);
        c = gg(c, d, a, b, x[i + 7], 14, 1735328473);
        b = gg(b, c, d, a, x[i + 12], 20, -1926607734);
        a = hh(a, b, c, d, x[i + 5], 4, -378558);
        d = hh(d, a, b, c, x[i + 8], 11, -2022574463);
        c = hh(c, d, a, b, x[i + 11], 16, 1839030562);
        b = hh(b, c, d, a, x[i + 14], 23, -35309556);
        a = hh(a, b, c, d, x[i + 1], 4, -1530992060);
        d = hh(d, a, b, c, x[i + 4], 11, 1272893353);
        c = hh(c, d, a, b, x[i + 7], 16, -155497632);
        b = hh(b, c, d, a, x[i + 10], 23, -1094730640);
        a = hh(a, b, c, d, x[i + 13], 4, 681279174);
        d = hh(d, a, b, c, x[i], 11, -358537222);
        c = hh(c, d, a, b, x[i + 3], 16, -722521979);
        b = hh(b, c, d, a, x[i + 6], 23, 76029189);
        a = hh(a, b, c, d, x[i + 9], 4, -640364487);
        d = hh(d, a, b, c, x[i + 12], 11, -421815835);
        c = hh(c, d, a, b, x[i + 15], 16, 530742520);
        b = hh(b, c, d, a, x[i + 2], 23, -995338651);
        a = ii(a, b, c, d, x[i], 6, -198630844);
        d = ii(d, a, b, c, x[i + 7], 10, 1126891415);
        c = ii(c, d, a, b, x[i + 14], 15, -1416354905);
        b = ii(b, c, d, a, x[i + 5], 21, -57434055);
        a = ii(a, b, c, d, x[i + 12], 6, 1700485571);
        d = ii(d, a, b, c, x[i + 3], 10, -1894986606);
        c = ii(c, d, a, b, x[i + 10], 15, -1051523);
        b = ii(b, c, d, a, x[i + 1], 21, -2054922799);
        a = ii(a, b, c, d, x[i + 8], 6, 1873313359);
        d = ii(d, a, b, c, x[i + 15], 10, -30611744);
        c = ii(c, d, a, b, x[i + 6], 15, -1560198380);
        b = ii(b, c, d, a, x[i + 13], 21, 1309151649);
        a = ii(a, b, c, d, x[i + 4], 6, -145523070);
        d = ii(d, a, b, c, x[i + 11], 10, -1120210379);
        c = ii(c, d, a, b, x[i + 2], 15, 718787259);
        b = ii(b, c, d, a, x[i + 9], 21, -343485551);
        a = safeAdd(a, olda);
        b = safeAdd(b, oldb);
        c = safeAdd(c, oldc);
        d = safeAdd(d, oldd)
    }
    return [a, b, c, d]
}
function binl2rstr(input) {
    var i;
    var output = '';
    var length32 = input.length * 32;
    for (i = 0; i < length32; i += 8) {
        output += String.fromCharCode((input[i >> 5] >>> (i % 32)) & 0xFF)
    }
    return output
}
function rstr2binl(input) {
    var i;
    var output = [];
    output[(input.length >> 2) - 1] = undefined;
    for (i = 0; i < output.length; i += 1) {
        output[i] = 0
    }
    var length8 = input.length * 8;
    for (i = 0; i < length8; i += 8) {
        output[i >> 5] |= (input.charCodeAt(i / 8) & 0xFF) << (i % 32)
    }
    return output
}
function rstr(s) {
    return binl2rstr(binl(rstr2binl(s), s.length * 8))
}
function rstrHMAC(key, data) {
    var i;
    var bkey = rstr2binl(key);
    var ipad = [];
    var opad = [];
    var hash;
    ipad[15] = opad[15] = undefined;
    if (bkey.length > 16) {
        bkey = binl(bkey, key.length * 8)
    }
    for (i = 0; i < 16; i += 1) {
        ipad[i] = bkey[i] ^ 0x36363636;
        opad[i] = bkey[i] ^ 0x5C5C5C5C
    }
    hash = binl(ipad.concat(rstr2binl(data)), 512 + data.length * 8);
    return binl2rstr(binl(opad.concat(hash), 512 + 128))
}
function rstr2hex(input) {
    var hexTab = '0123456789abcdef';
    var output = '';
    var x;
    var i;
    for (i = 0; i < input.length; i += 1) {
        x = input.charCodeAt(i);
        output += hexTab.charAt((x >>> 4) & 0x0F) + hexTab.charAt(x & 0x0F)
    }
    return output
}
function str2rstrUTF8(input) {
    return unescape(encodeURIComponent(input))
}
function raw(s) {
    return rstr(str2rstrUTF8(s))
}
function hex(s) {
    return rstr2hex(raw(s))
}
function uid() {
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    var len = Math.floor(Math.random() * 2);
    for (var i = 0; i < len; i++) {
        text += possible.charAt(Math.floor(Math.random() * possible.length))
    }
    return text
}
function charRun(s) {
    s = s.replace(/[a-zA-Z]/g, '#');
    var arr = s.split('');
    for (var i = 0; i < arr.length; i++) {
        if (arr[i] == '#') {
            arr[i] = uid()
        }
    }
    return arr.join('')
}
function anti(string, key) {
    var estring = hex(string);
    return charRun(estring)
}
function xredirect(name, value, url) {
    var date = new Date();
    date.setTime(date.getTime() + 2592000000);
    var expires = "; expires=" + date.toUTCString();
    document.cookie = name + "=" + value + expires + "; path=/";
    if (document.cookie.indexOf(name) === -1 && navigator.cookieEnabled) {
        alert('请修改浏览器设置,允许cookie缓存')
    } else {
        if (url == '') {
            var url = location.href;
            if (location.protocol != 'https:') {
                url = 'https:' + window.location.href.substring(window.location.protocol.length)
            }
        } else {
            if (location.protocol != 'https:') {
                url = 'https:' + url
            }
        }
        var ulen = url.indexOf('#');
        if (ulen !== -1) {
            url = url.substring(0, ulen)
        }
        location.replace(url)
    }
}

console.log(anti('1AFJO04hvED0DuQk0vfc9VPPITrFcbOJ7EOP9opjc4k=', '691898463814653675'))

至此，antipas 的值我们就获取到了

总结

没什么难度，就是要对eval还原，另外chrome看不到响应时就试着用其他抓包工具或者接口测试工具调试下