Android SSL MITM

This projects helps you to easily setup man-in-the-middle proxy for virtual android device.

Includes NGINX as a reverse-proxy, CoreDNS as a resolver and Debian image.

DEMO (12:41): https://youtu.be/QS1VPGZRf2U

The NGINX part is actually using OpenResty, which includes Lua module. I am using this to automatically issue certificates on demand.

I also create a certificate authority. (1 self-signed root CA and 1 intermediate CA signed by that root) Then via android emulator's -writable-system option, pushing those as trusted root certificates at the system level. Removing all other certificates in the process! (In the virtual device itself)

Prerequistes:

• Docker and docker-compose
• Android SDK (only command line tools are enough)
• Android Emulator
• Android System Image: 25, Google APIs
• Set your $ANDROID_SDK_ROOT to proper value;
  • on macOS: export ANDROID_SDK_ROOT="${HOME}/Library/Android/sdk"

Usage:

• Clone the repository.
• Execute make inside the repo.

$ git clone https://github.com/pvtmert/android-ssl-mitm.git
$ make -C android-ssl-mitm ANDROID_SDK_ROOT="${HOME}/Library/Android/sdk"

Optionally, comment out ./ssl:/home/ssl:rw in docker-compose.yml to see generated certs and possibly use them in Wireshark...

How it works:

• docker-compose Creates 3 services;
  • adb: Waits for root certificate creation. Then connects to the android emulator, removes & adds those certificates to the system.
  • dns: CoreDNS resolver for all possible domains. See Corefile.
  • http: OpenResty (NGINX) reverse proxy for connection handling
    • cert.sh: Initializes root and intermediate CAs.
    • issue.sh: Script to issue a certificate signed by CA.
    • nginx.conf: NGINX config with embedded Lua blocks.
• make first creates containers then android virtual device.
  • Virtual device named androidemu will be created.
  • AVD name can be overridden using EMULATOR_NAME variable.
  • Memory size in MB of AVD is 2048, EMULATOR_MEMORY can override that.
  • Android version can be changed using: make EMULATOR_VER=android-28 .... This will download image if it does not exist on the system.
    • Currently android-29 and android-30 gets into reboot-loop because of edited system image.
• Put any APK you want to install in this directory (root of the repo)
  • The adb service will install them automatically.