Default HTTPS repos with tor+https that are confirmed to be functional:
cat /etc/apt/sources.list
deb tor+https://deb.debian.org/debian stretch main contrib non-free
deb-src tor+https://deb.debian.org/debian stretch main contrib non-free
## Security updates
deb tor+https://deb.debian.org/debian-security stretch/updates main contrib non-free
deb-src tor+https://deb.debian.org/debian-security stretch/updates main contrib non-free
Default HTTPS repos with tor+https that are confirmed to be functional: