使用Frida繞過Android App的SSL Pinning

作者	原文傳送
littley	www.littley.top

簡介

證書鎖定（Certificate pinning）是遠程服務器在應用程序本身中信任的硬編碼證書，因此它將忽略設備證書存儲，並將信任自己的硬編碼證書，進一步的應用程序將使用該硬編碼證書“安全地”與遠程服務器通信。

環境需求

• windows10
• Android虛擬機（或真機）（本文采用的mumu模擬器）
• 安裝adb驅動
• 安裝frida （python爲3.7）
• 安裝Burpsuite（本文采用burpsuite_pro_v2.0）

注：經測試如果Burpsuite只是做繞過sslping功能，在模擬器或手機中可以不用安裝Burpsuite的證書，後面會講如何使用該證書

下載並設置burpsuite證書

先運行burpsuit並設置好代理端口我這裏用的是8888端口附圖
在瀏覽器讓訪問：http://192.168.1.107:8888/並點擊CA Certificate下載證書

連接adb命令如下

adb connect 127.0.0.1:7555

使adb將證書上傳到模擬器/data/local/tmp目錄中，注意，這裏是將cacert.der推送到模擬器重命名爲cert-der.crt

adb push cacert.der /data/local/tmp/cert-der.crt

設置模擬器代理端口

運行frida腳本

將下面腳本保存名爲fridascript.js

/* 

   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-pause

https://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 InputStream

     console.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 CAs

     console.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 KeyStore

     console.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);

運行frida-server

adb connect 127.0.0.1:7555#上面已經連接這句可以略過
adb shell
cd /data/local/tmp

chmod 777 frida-server

./frida-server# 

選運行你的app，並用frida-ps -U查看你的應用程序包名，也可以通過其他方式獲取包名
cmd

frida-ps -U

將 fridascript.js 注入到 到目標應用程序中

frida -U -f <包名> -l  fridascript.js --no-paus
例：frida -U -f com.twitter.android  -l  fridascript.js --no-paus

如圖上執行成功，然後我們操作一下app去burpstie裏看下

可以攔截到請求

相關參考資料
https://bbs.pediy.com/thread-222427.htm
https://www.freebuf.com/articles/terminal/214540.html

作者	原文傳送
littley	www.littley.top