背景
火线某个私密项目中涉及到一个app的测试，打开一看，证书校验--不让抓包，信息加密-无法篡改，遇到这种情况怎么，正常我这种小菜鸡都是直接放弃了，奈何厂家奖金给的高啊，我还是得想办法搞一搞，虽然到最后低危都没有捡到一个，但是还是分享给没有做过app的大佬参考一下。
一、 frida安装
01
Frida概述
Frida是一款轻量级HOOK框架，可用于多平台上，例如android、windows、ios等。
frida分为两部分，服务端运行在目标机上，通过注入进程的方式来实现劫持应用函数，另一部分运行在系统机器上。
frida上层接口支持js、python、c等。
Frida官方github地址为：
https://github.com/frida02
Frida安装
1 、安装python3.7并配置好环境变量（官方推荐python3以上版本至少为3.7），python安装包官方下载地址：
https://www.python.org/downloads/2 、安装frida模块，命令为pip install frida(配置了多个python版本环境的可以使用命令python -m pip install frida防止用pip install frida命令报错)。
3、安装frida-tools模块，命令同上，pip install frida-tools或者python -m pip install frida-tools。
4、下载运行在目标机上的frida-sever端
官方下载地址：https://github.com/frida/frida/releases后面可以跟版本14.2.2下载时要选择对应的版本下载，例如我的机器为arm32为架构，就选择frida-server-14.2.2-android-arm.xz下载。（可以在adb使用命令cat /proc/cpuinfo查询）
5、将第四步下载好的文件解压，然后通过命令adb push 你的电脑是存放位置 /data/local/tmp将文件传输到手机中，然后通过adb shell进入手机端，给文件赋权777，并于root权限启动。
6、做完以上几步后，新开一个命令行输入命令frida-ps -U查看手机进程，如果出现以下结果，则frida安装成功。
可以看到进程了
二、使用Frida脚本绕过抓包限制
设置burp证书
先在burp里设置本机代理
访问代理地址并下载burp证书
将下载的burp证书导入到手机中/data/local/tmp目录下，并重命名为cert-der.crt（此名称在接下来的fridascript.js脚本中使用，如果该名字命名为其他则脚本中相对应的地方也需要进行替换）
adb push cacert.der /data/local/tmp/cert-der.crt模拟器设置代理，在安卓手机设置->wlan选择对应网络设置代理
打开你想抓包的软件，使用frida-ps -U命令列出设备上运行的服务，找到对应的包名
在本地新建一个js文件，并将一下内容写入
/*Android SSL Re-pinning frida script v0.2 030417-pier$ adb push burpca-cert-der.crt /data/local/tmp/cert-der.crt$ frida -U -f it.app.mobile -l frida-android-repinning.js --no-pausehttps://techblog.mediaservice.net/2017/07/universal-android-ssl-pinning-bypass-with-frida/UPDATE 20191605: Fixed undeclared var. Thanks to @oleavr and @ehsanpc9999 !*/setTimeout(function(){Java.perform(function (){console.log("");console.log("[.] Cert Pinning Bypass/Re-Pinning");var CertificateFactory = Java.use("java.security.cert.CertificateFactory");var FileInputStream = Java.use("java.io.FileInputStream");var BufferedInputStream = Java.use("java.io.BufferedInputStream");var X509Certificate = Java.use("java.security.cert.X509Certificate");var KeyStore = Java.use("java.security.KeyStore");var TrustManagerFactory = Java.use("javax.net.ssl.TrustManagerFactory");var SSLContext = Java.use("javax.net.ssl.SSLContext");// Load CAs from an InputStreamconsole.log("[+] Loading our CA...")var cf = CertificateFactory.getInstance("X.509");try {var fileInputStream = FileInputStream.$new("/data/local/tmp/cert-der.crt");}catch(err) {console.log("[o] " + err);}var bufferedInputStream = BufferedInputStream.$new(fileInputStream);var ca = cf.generateCertificate(bufferedInputStream);bufferedInputStream.close();var certInfo = Java.cast(ca, X509Certificate);console.log("[o] Our CA Info: " + certInfo.getSubjectDN());// Create a KeyStore containing our trusted CAsconsole.log("[+] Creating a KeyStore for our CA...");var keyStoreType = KeyStore.getDefaultType();var keyStore = KeyStore.getInstance(keyStoreType);keyStore.load(null, null);keyStore.setCertificateEntry("ca", ca);// Create a TrustManager that trusts the CAs in our KeyStoreconsole.log("[+] Creating a TrustManager that trusts the CA in our KeyStore...");var tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();var tmf = TrustManagerFactory.getInstance(tmfAlgorithm);tmf.init(keyStore);console.log("[+] Our TrustManager is ready...");console.log("[+] Hijacking SSLContext methods now...")console.log("[-] Waiting for the app to invoke SSLContext.init()...")SSLContext.init.overload("[Ljavax.net.ssl.KeyManager;", "[Ljavax.net.ssl.TrustManager;", "java.security.SecureRandom").implementation = function(a,b,c) {console.log("[o] App invoked javax.net.ssl.SSLContext.init...");SSLContext.init.overload("[Ljavax.net.ssl.KeyManager;", "[Ljavax.net.ssl.TrustManager;", "java.security.SecureRandom").call(this, a, tmf.getTrustManagers(), c);console.log("[+] SSLContext initialized with our custom TrustManager!");}});},0);
脚本里的30行其中对应的就是burp证书的信息
将fridascript.js注入到目标应用程序中
frida -U -f com.xxxx.app.ui -l C:UsersxxxDesktopfridascript.js --no-pause-f选项表示强制启动一个应用程序，-l选项表示加载指定脚本，–no-pause选项表示不中断应用程序的启动，如下所示代表运行成功
咱们可以看到，已经能抓到包了
但是包的内容进行了加密
三、使用Frida脚本让他自己吐出密钥信息
还需要再本地建一个新的js文件，代码如下：
var N_ENCRYPT_MODE = 1var N_DECRYPT_MODE = 2function showStacks() {var Exception = Java.use("java.lang.Exception");var ins = Exception.$new("Exception");var straces = ins.getStackTrace();if (undefined == straces || null == straces) {return;}console.log("============================= Stack strat=======================");console.log("");for (var i = 0; i < straces.length; i++) {var str = " " + straces[i].toString();console.log(str);}console.log("");console.log("============================= Stack end=======================rn");Exception.$dispose();}//工具相关函数var base64EncodeChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',base64DecodeChars = new Array((-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), (-1), 62, (-1), (-1), (-1), 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, (-1), (-1), (-1), (-1), (-1), (-1), (-1), 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, (-1), (-1), (-1), (-1), (-1), (-1), 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, (-1), (-1), (-1), (-1), (-1));function stringToBase64(e) {var r, a, c, h, o, t;for (c = e.length, a = 0, r = ''; a < c;) {if (h = 255 & e.charCodeAt(a++), a == c) {r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4),r += '==';break}if (o = e.charCodeAt(a++), a == c) {r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4 | (240 & o) >> 4),r += base64EncodeChars.charAt((15 & o) << 2),r += '=';break}t = e.charCodeAt(a++),r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4 | (240 & o) >> 4),r += base64EncodeChars.charAt((15 & o) << 2 | (192 & t) >> 6),r += base64EncodeChars.charAt(63 & t)}return r}function base64ToString(e) {var r, a, c, h, o, t, d;for (t = e.length, o = 0, d = ''; o < t;) {dor = base64DecodeChars[255 & e.charCodeAt(o++)];while (o < t && r == -1);if (r == -1)break;doa = base64DecodeChars[255 & e.charCodeAt(o++)];while (o < t && a == -1);if (a == -1)break;d += String.fromCharCode(r << 2 | (48 & a) >> 4);do {if (c = 255 & e.charCodeAt(o++), 61 == c)return d;c = base64DecodeChars[c]} while (o < t && c == -1);if (c == -1)break;d += String.fromCharCode((15 & a) << 4 | (60 & c) >> 2);do {if (h = 255 & e.charCodeAt(o++), 61 == h)return d;h = base64DecodeChars[h]} while (o < t && h == -1);if (h == -1)break;d += String.fromCharCode((3 & c) << 6 | h)}return d}function hexToBase64(str) {return base64Encode(String.fromCharCode.apply(null, str.replace(/r|n/g, "").replace(/([da-fA-F]{2}) ?/g, "0x$1 ").replace(/ +$/, "").split(" ")));}function base64ToHex(str) {for (var i = 0, bin = base64Decode(str.replace(/[ rn]+$/, "")), hex = []; i < bin.length; ++i) {var tmp = bin.charCodeAt(i).toString(16);if (tmp.length === 1)tmp = "0" + tmp;hex[hex.length] = tmp;}return hex.join("");}function hexToBytes(str) {var pos = 0;var len = str.length;if (len % 2 != 0) {return null;}len /= 2;var hexA = new Array();for (var i = 0; i < len; i++) {var s = str.substr(pos, 2);var v = parseInt(s, 16);hexA.push(v);pos += 2;}return hexA;}function bytesToHex(arr) {var str = '';var k, j;for (var i = 0; i < arr.length; i++) {k = arr[i];j = k;if (k < 0) {j = k + 256;}if (j < 16) {str += "0";}str += j.toString(16);}return str;}function stringToHex(str) {var val = "";for (var i = 0; i < str.length; i++) {if (val == "")val = str.charCodeAt(i).toString(16);elseval += str.charCodeAt(i).toString(16);}return val}function stringToBytes(str) {var ch, st, re = [];for (var i = 0; i < str.length; i++) {ch = str.charCodeAt(i);st = [];do {st.push(ch & 0xFF);ch = ch >> 8;}while (ch);re = re.concat(st.reverse());}return re;}//将byte[]转成String的方法function bytesToString(arr) {var str = '';arr = new Uint8Array(arr);for (var i in arr) {str += String.fromCharCode(arr[i]);}return str;}function bytesToBase64(e) {var r, a, c, h, o, t;for (c = e.length, a = 0, r = ''; a < c;) {if (h = 255 & e[a++], a == c) {r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4),r += '==';break}if (o = e[a++], a == c) {r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4 | (240 & o) >> 4),r += base64EncodeChars.charAt((15 & o) << 2),r += '=';break}t = e[a++],r += base64EncodeChars.charAt(h >> 2),r += base64EncodeChars.charAt((3 & h) << 4 | (240 & o) >> 4),r += base64EncodeChars.charAt((15 & o) << 2 | (192 & t) >> 6),r += base64EncodeChars.charAt(63 & t)}return r}function base64ToBytes(e) {var r, a, c, h, o, t, d;for (t = e.length, o = 0, d = []; o < t;) {dor = base64DecodeChars[255 & e.charCodeAt(o++)];while (o < t && r == -1);if (r == -1)break;doa = base64DecodeChars[255 & e.charCodeAt(o++)];while (o < t && a == -1);if (a == -1)break;d.push(r << 2 | (48 & a) >> 4);do {if (c = 255 & e.charCodeAt(o++), 61 == c)return d;c = base64DecodeChars[c]} while (o < t && c == -1);if (c == -1)break;d.push((15 & a) << 4 | (60 & c) >> 2);do {if (h = 255 & e.charCodeAt(o++), 61 == h)return d;h = base64DecodeChars[h]} while (o < t && h == -1);if (h == -1)break;d.push((3 & c) << 6 | h)}return d}//stringToBase64 stringToHex stringToBytes//base64ToString base64ToHex base64ToBytes// hexToBase64 hexToBytes// bytesToBase64 bytesToHex bytesToStringJava.perform(function () {var secretKeySpec = Java.use('javax.crypto.spec.SecretKeySpec');secretKeySpec.$init.overload('[B', 'java.lang.String').implementation = function (a, b) {showStacks();var result = this.$init(a, b);console.log("======================================");console.log("算法名：" + b + "|str密钥:" + bytesToString(a));console.log("算法名：" + b + "|Hex密钥:" + bytesToHex(a));return result;}var DESKeySpec = Java.use('javax.crypto.spec.DESKeySpec');DESKeySpec.$init.overload('[B').implementation = function (a) {showStacks();var result = this.$init(a);console.log("======================================");var bytes_key_des = this.getKey();console.log("des密钥 |str " + bytesToString(bytes_key_des));console.log("des密钥 |hex " + bytesToHex(bytes_key_des));return result;}DESKeySpec.$init.overload('[B', 'int').implementation = function (a, b) {showStacks();var result = this.$init(a, b);console.log("======================================");var bytes_key_des = this.getKey();console.log("des密钥 |str " + bytesToString(bytes_key_des));console.log("des密钥 |hex " + bytesToHex(bytes_key_des));return result;}var mac = Java.use('javax.crypto.Mac');mac.getInstance.overload('java.lang.String').implementation = function (a) {showStacks();var result = this.getInstance(a);console.log("======================================");console.log("算法名：" + a);return result;}mac.update.overload('[B').implementation = function (a) {//showStacks();this.update(a);console.log("======================================");console.log("update:" + bytesToString(a))}mac.update.overload('[B', 'int', 'int').implementation = function (a, b, c) {//showStacks();this.update(a, b, c)console.log("======================================");console.log("update:" + bytesToString(a) + "|" + b + "|" + c);}mac.doFinal.overload().implementation = function () {//showStacks();var result = this.doFinal();console.log("======================================");console.log("doFinal结果: |str :" + bytesToString(result));console.log("doFinal结果: |hex :" + bytesToHex(result));console.log("doFinal结果: |base64 :" + bytesToBase64(result));return result;}mac.doFinal.overload('[B').implementation = function (a) {//showStacks();var result = this.doFinal(a);console.log("======================================");console.log("doFinal参数: |str :" + bytesToString(a));console.log("doFinal参数: |hex :" + bytesToHex(a));console.log("doFinal结果: |str :" + bytesToString(result));console.log("doFinal结果: |hex :" + bytesToHex(result));console.log("doFinal结果: |base64 :" + bytesToBase64(result));return result;}var md = Java.use('java.security.MessageDigest');md.getInstance.overload('java.lang.String', 'java.lang.String').implementation = function (a, b) {//showStacks();console.log("======================================");console.log("算法名：" + a);return this.getInstance(a, b);}md.getInstance.overload('java.lang.String').implementation = function (a) {//showStacks();console.log("======================================");console.log("算法名：" + a);return this.getInstance(a);}md.update.overload('[B').implementation = function (a) {//showStacks();console.log("======================================");console.log("update:" + bytesToString(a))return this.update(a);}md.update.overload('[B', 'int', 'int').implementation = function (a, b, c) {//showStacks();console.log("======================================");console.log("update:" + bytesToString(a) + "|" + b + "|" + c);return this.update(a, b, c);}md.digest.overload().implementation = function () {//showStacks();console.log("======================================");var result = this.digest();console.log("digest结果 |hex:" + bytesToHex(result));console.log("digest结果 |base64:" + bytesToBase64(result));return result;}md.digest.overload('[B').implementation = function (a) {//showStacks();console.log("======================================");console.log("digest参数 |str:" + bytesToString(a));console.log("digest参数 |hex:" + bytesToHex(a));var result = this.digest(a);console.log("digest结果: |hex" + bytesToHex(result));console.log("digest结果: |base64" + bytesToBase64(result));return result;}var ivParameterSpec = Java.use('javax.crypto.spec.IvParameterSpec');ivParameterSpec.$init.overload('[B').implementation = function (a) {//showStacks();var result = this.$init(a);console.log("======================================");console.log("iv向量: |str:" + bytesToString(a));console.log("iv向量: |hex:" + bytesToHex(a));return result;}var cipher = Java.use('javax.crypto.Cipher');cipher.getInstance.overload('java.lang.String').implementation = function (a) {//showStacks();var result = this.getInstance(a);console.log("======================================");console.log("模式填充:" + a);return result;}cipher.init.overload('int', 'java.security.Key').implementation = function (a, b) {//showStacks();var result = this.init(a, b);console.log("======================================");if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.init.overload('int', 'java.security.cert.Certificate').implementation = function (a, b) {//showStacks();var result = this.init(a, b);console.log("======================================");if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}return result;}cipher.init.overload('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec').implementation = function (a, b, c) {//showStacks();var result = this.init(a, b, c);console.log("======================================");if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.init.overload('int', 'java.security.cert.Certificate', 'java.security.SecureRandom').implementation = function (a, b, c) {//showStacks();var result = this.init(a, b, c);if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}return result;}cipher.init.overload('int', 'java.security.Key', 'java.security.SecureRandom').implementation = function (a, b, c) {//showStacks();var result = this.init(a, b, c);if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.init.overload('int', 'java.security.Key', 'java.security.AlgorithmParameters').implementation = function (a, b, c) {//showStacks();var result = this.init(a, b, c);if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.init.overload('int', 'java.security.Key', 'java.security.AlgorithmParameters', 'java.security.SecureRandom').implementation = function (a, b, c, d) {//showStacks();var result = this.init(a, b, c, d);if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.init.overload('int', 'java.security.Key', 'java.security.spec.AlgorithmParameterSpec', 'java.security.SecureRandom').implementation = function (a, b, c, d) {//showStacks();var result = this.init(a, b, c, d);if (N_ENCRYPT_MODE == a){console.log("init | 加密模式");}else if(N_DECRYPT_MODE == a){console.log("init | 解密模式");}var bytes_key = b.getEncoded();console.log("init key:" + "|str密钥:" + bytesToString(bytes_key));console.log("init key:" + "|Hex密钥:" + bytesToHex(bytes_key));return result;}cipher.update.overload('[B').implementation = function (a) {//showStacks();var result = this.update(a);console.log("======================================");console.log("update:" + bytesToString(a));return result;}cipher.update.overload('[B', 'int', 'int').implementation = function (a, b, c) {//showStacks();var result = this.update(a, b, c);console.log("======================================");console.log("update:" + bytesToString(a) + "|" + b + "|" + c);return result;}cipher.doFinal.overload().implementation = function () {//showStacks();var result = this.doFinal();console.log("======================================");console.log("doFinal结果: |str :" + bytesToString(result));console.log("doFinal结果: |hex :" + bytesToHex(result));console.log("doFinal结果: |base64 :" + bytesToBase64(result));return result;}cipher.doFinal.overload('[B').implementation = function (a) {//showStacks();var result = this.doFinal(a);console.log("======================================");console.log("doFinal参数: |str :" + bytesToString(a));console.log("doFinal参数: |hex :" + bytesToHex(a));console.log("doFinal结果: |str :" + bytesToString(result));console.log("doFinal结果: |hex :" + bytesToHex(result));console.log("doFinal结果: |base64 :" + bytesToBase64(result));return result;}var x509EncodedKeySpec = Java.use('java.security.spec.X509EncodedKeySpec');x509EncodedKeySpec.$init.overload('[B').implementation = function (a) {//showStacks();var result = this.$init(a);console.log("======================================");console.log("RSA密钥:" + bytesToBase64(a));return result;}var rSAPublicKeySpec = Java.use('java.security.spec.RSAPublicKeySpec');rSAPublicKeySpec.$init.overload('java.math.BigInteger', 'java.math.BigInteger').implementation = function (a, b) {//showStacks();var result = this.$init(a, b);console.log("======================================");//console.log("RSA密钥:" + bytesToBase64(a));console.log("RSA密钥N:" + a.toString(16));console.log("RSA密钥E:" + b.toString(16));return result;}var KeyPairGenerator = Java.use('java.security.KeyPairGenerator');KeyPairGenerator.generateKeyPair.implementation = function (){//showStacks();var result = this.generateKeyPair();console.log("======================================");var str_private = result.getPrivate().getEncoded();var str_public = result.getPublic().getEncoded();console.log("公钥 |hex" + bytesToHex(str_public));console.log("私钥 |hex" + bytesToHex(str_private));return result;}KeyPairGenerator.genKeyPair.implementation = function (){//showStacks();var result = this.genKeyPair();console.log("======================================");var str_private = result.getPrivate().getEncoded();var str_public = result.getPublic().getEncoded();console.log("公钥 |hex" + bytesToHex(str_public));console.log("私钥 |hex" + bytesToHex(str_private));return result;}});
在新建一个窗口
frida -U -f com.xxxx.app.ui -l C:UsersxxxDesktop333.js --no-pause
如上图所示，已经在开始自动解密了
密钥信息已经出来啦，只需要到网上找对应的脚本进行解密就可以了
参考资料：
https://www.52pojie.cn/thread-1128884-1-1.htmlhttps://blog.csdn.net/weixin_44677409/article/details/106650473https://www.jianshu.com/p/ecbee028022b
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【周度激励】2021.8.2 ～ 2021.8.8公告
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火线Zone是[火线安全平台]运营的封闭式社区，社区成员必须在[火线安全平台]提交有效漏洞才能申请免费加入,符合要求的白帽子可联系[火线小助手]加入。
我们不希望出现劣币驱逐良币的结果，我们不希望一个技术社区变成一个水区！
欢迎具备分享精神的白帽子加入火线Zone，共建一个有技术氛围的优质社区！
本文始发于微信公众号（火线Zone）：一个脚本让你的app自动吐出密钥信息
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