For analysis and reverse engineering, it can be helpful to insert a
custom CA certificate into Waydroid’s system-wide trust store.
Users used to be able to do that via Android’s settings but not anymore.
The `install mitm` command accepts a path to a file that contains a
– typically self-signed – CA certificate in PEM format.
It then renames [1] and copies the file into the overlay file system,
placing it into Waydroid’s trust store.
As a usage example, the following command lines enable your host to use
mitmproxy [2] to act as a proxy and to intercept [3] HTTP(S) connections
that come from the Waydroid container:
```sh
$ timeout --preserve-status 2 mitmdump -n # creates a CA cert in ~/.mitmproxy
$ sudo venv/bin/python3 main.py install mitm --ca-cert ~/.mitmproxy/mitmproxy-ca-cert.pem
INFO: Creating directory: /system/etc/security/cacerts
INFO: Copying /home/yourname/.mitmproxy/mitmproxy-ca-cert.pem to system trust store
INFO: Target file: /system/etc/security/cacerts/6320a7db.0
INFO: mitm installation finished
$ sudo waydroid shell -- ls -l /system/etc/security/cacerts # double-check that it worked
[…]
-rw-r--r-- 1 root root 1191 2024-01-01 00:00 6320a7db.0
[…]
$ adb shell settings put global http_proxy ${YOUR_IP_HERE?}:3128 # tell Waydroid to use the proxy
# for all connections
$ mitmproxy -p 3128 # start proxy and display a TUI
# with HTTP(S) connections
# coming from Waydroid
```
[1]: https://docs.mitmproxy.org/stable/howto-install-system-trusted-ca-android/#2-rename-certificate
[2]: https://mitmproxy.org/
[3]: https://docs.mitmproxy.org/stable/mitmproxytutorial-interceptrequests/
Claudia