Frida Intercept Encrypted Api

📍What does it help?

Banking applications, e-wallets, .. are increasingly enhanced security to fight hackers. One of them is to encrypt request/response data when sending and receiving. Some weak encryptions can be decrypted easily, but some strong encryptions like RSA are difficult. When pentesting a normal mobile application, we just need to set it up so that BurpSuite can intercept the request / response of the APIs that the application uses. But when pentesting a banking or e-wallet application with end-to-end encrypted API, with the usual BurpSuite setup we cannot see the content of the API. Hooking into functions that send request/response and intercept data before it is encrypted is one way we can view and modify data.

Architecture

For IOS

Configurage ios_handlers.js

1. Add your Request / Response Class & Method

/*Request Class & Method*/
var search_request_class  = [''];
var search_request_method = [''];

/*Response Class & Method*/
var search_response_class  = [''];
var search_response_method = [''];`

2. Debug ARGS in Class & Method

/*DEBUG REQUEST HERE*/
console.log(colors.green,"[DEBUG-REQUEST] Dump Arugment in method: ",colors.resetColor);
print_arguments(args);

For Android

Configurage android_handlers.js

1. Add your Request / Response Class & Method

/*Request Class & Method*/
    var request_class = Java.use('');
    var request_method = '';

    /*Response Class & Method*/
    var response_class = Java.use('');
    var response_method = '';

Usage

1. Load burpsuite_configuration_proxy.json or Set up Burpsuite Proxy by following the steps below
   • Listen on 127.0.0.1:26080
   • Redirect to 127.0.0.1:27080 and Check (Support invisible proxying)
2. Run echoServer.py
3. Config and optimize _handlers.js
4. Run burpTracer.py -p com.apple.AppStore / [-n 'App Store']

Note: Different applications will use different libraries. You need to reverse or trace the application to find the correct function.

Technical Presentation

Title	Link
Frida Intercept Encrypted Api	https://medium.com/p/a5c4ef22a093
Frida Intercept Encrypted API | Technical | How to Intercept Encrypted APIs on The Application | Part 1	https://youtu.be/BIB3ma3Tl34
Frida Intercept Encrypted API | Technical | How to Intercept Encrypted APIs on The Application | Part 2	https://youtu.be/IojcakLNtrA