export .0 cert file for rooted android devices

Description

We would like to add a feature on Mac to “Export certificates in .0 format.”

The current process is somewhat complex. I have to first download the certificate in .pem format on my phone and then convert it to .0 format.

For reference on how to convert a .pem certificate to .0 format, please check:
https://blog.csdn.net/haduwi/article/details/125696208

Why this feature/change is important?

I know that Proxyman currently offers a solution for exporting certificates in .pem format, but this process is a bit cumbersome. For rooted Android devices, there is actually a simpler way to capture network traffic:

After exporting the certificate in .pem format, you can use the following command:

openssl x509 -subject_hash_old -in CERT.pem

This command will get a filename at first line. Rename the file with a .0 extension.

Then, push the renamed file to the /system/etc/security/cacerts/ directory on the phone. This will allow you to capture network traffic easily without needing to configure res/xml/network_security_config.xml in your app.

Start by locating the existing Mac certificate export flow that produces PEM files. Check how the requested .0 filename should be derived from the certificate, then verify that the exported file can be used in the rooted Android cacerts directory as described; the issue names no files or tests.