一个通杀的Hook脚本与例子

一个通杀md5，sha，mac，des，3des，aes，rsa，数字签名 算法的hook脚本。

原理呢其实就是hook监控了一些加密库会调用到的底层函数。

先贴代码：

Java.perform(function () {

    function showStacks() {
        console.log(
            Java.use("android.util.Log")
                .getStackTraceString(
                    Java.use("java.lang.Throwable").$new()
                )
        );
    }
    var ByteString = Java.use("com.android.okhttp.okio.ByteString");
    function toBase64(tag, data) {
        console.log(tag + " Base64: ", ByteString.of(data).base64());
    }
    function toHex(tag, data) {
        console.log(tag + " Hex: ", ByteString.of(data).hex());
    }
    function toUtf8(tag, data) {
        console.log(tag + " Utf8: ", ByteString.of(data).utf8());
    }
    // toBase64([48,49,50,51,52]);
    // toHex([48,49,50,51,52]);
    // toUtf8([48,49,50,51,52]);
    //console.log(Java.enumerateLoadedClassesSync().join("\n"));

    var messageDigest = Java.use("java.security.MessageDigest");
    messageDigest.update.overload('byte').implementation = function (data) {
        console.log("MessageDigest.update('byte') is called!");
        return this.update(data);
    }
    messageDigest.update.overload('java.nio.ByteBuffer').implementation = function (data) {
        console.log("MessageDigest.update('java.nio.ByteBuffer') is called!");
        return this.update(data);
    }
    messageDigest.update.overload('[B').implementation = function (data) {
        console.log("MessageDigest.update('[B') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " update data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        console.log("=======================================================");
        return this.update(data);
    }
    messageDigest.update.overload('[B', 'int', 'int').implementation = function (data, start, length) {
        console.log("MessageDigest.update('[B', 'int', 'int') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " update data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        console.log("=======================================================", start, length);
        return this.update(data, start, length);
    }
    messageDigest.digest.overload().implementation = function () {
        console.log("MessageDigest.digest() is called!");
        var result = this.digest();
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " digest result";
        toHex(tag, result);
        toBase64(tag, result);
        console.log("=======================================================");
        return result;
    }
    messageDigest.digest.overload('[B').implementation = function (data) {
        console.log("MessageDigest.digest('[B') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " digest data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        var result = this.digest(data);
        var tags = algorithm + " digest result";
        toHex(tags, result);
        toBase64(tags, result);
        console.log("=======================================================");
        return result;
    }
    messageDigest.digest.overload('[B', 'int', 'int').implementation = function (data, start, length) {
        console.log("MessageDigest.digest('[B', 'int', 'int') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " digest data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        var result = this.digest(data, start, length);
        var tags = algorithm + " digest result";
        toHex(tags, result);
        toBase64(tags, result);
        console.log("=======================================================", start, length);
        return result;
    }

    var mac = Java.use("javax.crypto.Mac");
    mac.init.overload('java.security.Key', 'java.security.spec.AlgorithmParameterSpec').implementation = function (key, AlgorithmParameterSpec) {
        console.log("Mac.init('java.security.Key', 'java.security.spec.AlgorithmParameterSpec') is called!");
        return this.init(key, AlgorithmParameterSpec);
    }
    mac.init.overload('java.security.Key').implementation = function (key) {
        console.log("Mac.init('java.security.Key') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " init Key";
        var keyBytes = key.getEncoded();
        toUtf8(tag, keyBytes);
        toHex(tag, keyBytes);
        toBase64(tag, keyBytes);
        console.log("=======================================================");
        return this.init(key);
    }
    mac.update.overload('byte').implementation = function (data) {
        console.log("Mac.update('byte') is called!");
        return this.update(data);
    }
    mac.update.overload('java.nio.ByteBuffer').implementation = function (data) {
        console.log("Mac.update('java.nio.ByteBuffer') is called!");
        return this.update(data);
    }
    mac.update.overload('[B').implementation = function (data) {
        console.log("Mac.update('[B') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " update data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        console.log("=======================================================");
        return this.update(data);
    }
    mac.update.overload('[B', 'int', 'int').implementation = function (data, start, length) {
        console.log("Mac.update('[B', 'int', 'int') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " update data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        console.log("=======================================================", start, length);
        return this.update(data, start, length);
    }
    mac.doFinal.overload().implementation = function () {
        console.log("Mac.doFinal() is called!");
        var result = this.doFinal();
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " doFinal result";
        toHex(tag, result);
        toBase64(tag, result);
        console.log("=======================================================");
        return result;
    }

    var cipher = Java.use("javax.crypto.Cipher");
    cipher.init.overload('int', 'java.security.cert.Certificate').implementation = function () {
        console.log("Cipher.init('int', 'java.security.cert.Certificate') is called!");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.Key', 'java.security.SecureRandom').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key', 'java.security.SecureRandom') is called!");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.cert.Certificate', 'java.security.SecureRandom').implementation = function () {
        console.log("Cipher.init('int', 'java.security.cert.Certificate', 'java.security.SecureRandom') is called!");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.Key', 'java.security.AlgorithmParameters', 'java.security.SecureRandom').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key', 'java.security.AlgorithmParameters', 'java.security.SecureRandom') is called!");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec', 'java.security.SecureRandom').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec', 'java.security.SecureRandom') is called!");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.Key', 'java.security.AlgorithmParameters').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key', 'java.security.AlgorithmParameters') is called!");
        return this.init.apply(this, arguments);
    }

    cipher.init.overload('int', 'java.security.Key').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " init Key";
        var className = JSON.stringify(arguments[1]);
        if(className.indexOf("OpenSSLRSAPrivateKey") === -1){
            var keyBytes = arguments[1].getEncoded();
            toUtf8(tag, keyBytes);
            toHex(tag, keyBytes);
            toBase64(tag, keyBytes);
        }
        console.log("=======================================================");
        return this.init.apply(this, arguments);
    }
    cipher.init.overload('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec').implementation = function () {
        console.log("Cipher.init('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " init Key";
        var keyBytes = arguments[1].getEncoded();
        toUtf8(tag, keyBytes);
        toHex(tag, keyBytes);
        toBase64(tag, keyBytes);
        var tags = algorithm + " init iv";
        var iv = Java.cast(arguments[2], Java.use("javax.crypto.spec.IvParameterSpec"));
        var ivBytes = iv.getIV();
        toUtf8(tags, ivBytes);
        toHex(tags, ivBytes);
        toBase64(tags, ivBytes);
        console.log("=======================================================");
        return this.init.apply(this, arguments);
    }

    cipher.doFinal.overload('java.nio.ByteBuffer', 'java.nio.ByteBuffer').implementation = function () {
        console.log("Cipher.doFinal('java.nio.ByteBuffer', 'java.nio.ByteBuffer') is called!");
        return this.doFinal.apply(this, arguments);
    }
    cipher.doFinal.overload('[B', 'int').implementation = function () {
        console.log("Cipher.doFinal('[B', 'int') is called!");
        return this.doFinal.apply(this, arguments);
    }
    cipher.doFinal.overload('[B', 'int', 'int', '[B').implementation = function () {
        console.log("Cipher.doFinal('[B', 'int', 'int', '[B') is called!");
        return this.doFinal.apply(this, arguments);
    }
    cipher.doFinal.overload('[B', 'int', 'int', '[B', 'int').implementation = function () {
        console.log("Cipher.doFinal('[B', 'int', 'int', '[B', 'int') is called!");
        return this.doFinal.apply(this, arguments);
    }
    cipher.doFinal.overload().implementation = function () {
        console.log("Cipher.doFinal() is called!");
        return this.doFinal.apply(this, arguments);
    }

    cipher.doFinal.overload('[B').implementation = function () {
        console.log("Cipher.doFinal('[B') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " doFinal data";
        var data = arguments[0];
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        var result = this.doFinal.apply(this, arguments);
        var tags = algorithm + " doFinal result";
        toHex(tags, result);
        toBase64(tags, result);
        console.log("=======================================================");
        return result;
    }
    cipher.doFinal.overload('[B', 'int', 'int').implementation = function () {
        console.log("Cipher.doFinal('[B', 'int', 'int') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " doFinal data";
        var data = arguments[0];
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        var result = this.doFinal.apply(this, arguments);
        var tags = algorithm + " doFinal result";
        toHex(tags, result);
        toBase64(tags, result);
        console.log("=======================================================", arguments[1], arguments[2]);
        return result;
    }

    var signature = Java.use("java.security.Signature");
    signature.update.overload('byte').implementation = function (data) {
        console.log("Signature.update('byte') is called!");
        return this.update(data);
    }
    signature.update.overload('java.nio.ByteBuffer').implementation = function (data) {
        console.log("Signature.update('java.nio.ByteBuffer') is called!");
        return this.update(data);
    }
    signature.update.overload('[B', 'int', 'int').implementation = function (data, start, length) {
        console.log("Signature.update('[B', 'int', 'int') is called!");
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " update data";
        toUtf8(tag, data);
        toHex(tag, data);
        toBase64(tag, data);
        console.log("=======================================================", start, length);
        return this.update(data, start, length);
    }
    signature.sign.overload('[B', 'int', 'int').implementation = function () {
        console.log("Signature.sign('[B', 'int', 'int') is called!");
        return this.sign.apply(this, arguments);
    }
    signature.sign.overload().implementation = function () {
        console.log("Signature.sign() is called!");
        var result = this.sign();
        var algorithm = this.getAlgorithm();
        var tag = algorithm + " sign result";
        toHex(tag, result);
        toBase64(tag, result);
        console.log("=======================================================");
        return result;
    }

});

例子：

这里还是以嘟嘟牛来举例子。登陆的数据包：

这里可以看到登陆的请求数据包的内容的密文：

{"Encrypt":"NIszaqFPos1vd0pFqKlB42Np5itPxaNH\/\/FDsRnlBfgL4lcVxjXii\/UNcdXYMk0EYvcSRbr1TuoB\nsJgXGX8PVraEsOG990ViYRnY0aMqHtUpvZZdJeIQ\/OmD6Watu53ljmELISj4T8OaC3okf13vqPmz\n8+81YuNEjE+5eajFCE+9NtXfzsgPdNmS6+F14e0EgDIzPcjbCT0Bo900PH8nuvLecYmphBQp\n"}

我们看一下我们hook脚本监控到的内容，直接找到了明文密文与加密方式：

明文内容：

{"equtype":"ANDROID","loginImei":"Androidnull","sign":"7623B263EB072D0182BD6B7C93470C0D","timeStamp":"1675347372942","userPwd":"gghhhhh","username":"15149029981"}

但是可以看到我们的sign字段是同样经过加密过的，密文为

7623B263EB072D0182BD6B7C93470C0D

同样，我们去我们hook脚本监控到的内容中去找这段东西，也是找到了签名sign的明文和密文以及加密方式：

这里使用了好几组登陆数据进行抓包，发现hook到的sign的中的key的字段的值是一个常量。接下来就可以去对数据进行伪造了。