SuppSandroB

Maybe can also make custom CA as system CA if phone is rooted... https://blog.jeroenhd.nl/article/android-7-nougat-and-certificate-authorities

cert file is used if ssl client authentication is used. But probably this is not your case.

Try first to setup with username/password so squid3 will work okey. Then test with digest. Must say that digest is not very used auth any more. If you need better...

Yes. Drony is not open source but is fork of SandroProxy

I did tun2sock for Orbot so I know that is working okey. Problem is that is c++ and you need some time to learn how it works. Also PsiPhon uses...