SSL Pinning Bypass

Secure Socket Layer (SSL) and Transport Layer Security (TLS) ensure encrypted

Communication over the internet – specified as HTTPS. The security factors of SSL are based on the security certificates’ “Chain of Trust.” When a sender sent a message, the client checks the Server’s SSL certificate to confirm whether the certificate is issued by Trusted CA.

Certificate pinning forces your client app to validate the server’s certificate against a known copy. After pinning your server’s certificate inside your client app, your client should check the basic validity of the cert from the list above, as well as verify that the server’s certificate matches the pinned certificate.

SSL pinning bypass is a major step that needs to be done when we even start the dynamic analysis of HTTP requests for most of the mobile application nowadays as organizations are more concern about data privacy and secure transfer of data over the network from threads like Man-in-The-Middle (MiTM) attacks.

Frida is a framework that injects scripts to native apps to manipulate application’s logic in runtime which is a more dynamic approach for pentesting mobile applications.

1. Rooted device/emulator:
   
   I’m using genymotion for this one. Genymotion is easy to set-up and use and can download it from below.
   
   Click on this URL
   
   Python frida packages and adb installation:
   
   python -m pip install Frida
python -m pip install objection
python -m pip install frida-tools
   
   OR
   
   pip install Frida
pip install objection
pip install frida-tools
apt install adb
   
    
2. Setup and installation

   1. Connect device to adb:
      
      If you do not enable- first goto settings >> Developer options and enable debugging mode in device so that adb can communicate with the device.
       

      

   2. Install SSl pinning apk in device
      
      Step:1 Download apk – go to directory open terminal
      
      adb install -r twitter_9.69.0_androidapksbox.apk

      
      Step:2 Twitter installed in emulator

      
      Step:3 Open the application and Observe that the application is a SSL Pinning
       

      

   3. Frida Server Setup:
      
      Download latest frida server:
      
      Step:1 Click on this URL
      
      frida-server-12.4.7-android-x86
      
      frida-server-12.4.7-android-x86_64.xz
      
      Step:2 Now we need to push our frida-server file into the device. Extract and Copy “frida-server-12.4.7-android-x86” file in adb folder rename file as “frida-server”

      
      Step:3 following command → adb push frida-server /data/local/tmp/
      
      
      Step:4 Pushed this /data/local/tmp

      
       

      Step:5 Give permissions to frida-server → adb shell chmod 777 /data/local/tmp/frida-server
      
      
      Step:6 Push the certificate into the device and into the same location as the frida-server, name it cert-der.crt

      
      
      Step:7 Pushed this /data/local/tmp

      
      
      Step:8 Click on this URL, You can save this code as fridascript.js in the same folder as adb → adb push fridascript.js /data/local/tmp/ 
      

      
      Step:9 Pushed this /data/local/tmp

      
      
      Step:10 Check and run frida server in device → adb shell /data/local/tmp/frida-server &

      

      
      Step:11 Following command → frida-ps -Uai 
      

      
      Step:12 Find your application’s package name

      
      
      Step:13 Following command → frida -U -f  com.twitter.android   -l fridascript.js –no-paus

      
      
      Step:14 Your command to inject the fridascript.js script into the native application 

      

      
      
      Step:15 BOOM Bypassed!!. We are intercepting traffic into BurpSuite

      

That’s all for this blog, I hope you enjoyed reading this. In future, I will right one more blog that will include some other techniques.

Click here to see the reference