https://mullvad.net/en/help/install-mullvad-app-linux
Trying to install VPN and these are the instructions Mullvad is giving me. This is ridiculous. There must be a more simple way. I know how to follow the instructions but I have no idea what I’m doing here. Can’t I just download a file and install it? I’m on Ubuntu.
You can verify the signature of the manual download as well. Either way, you are trusting the files you download over HTTPS from mullvad.net. There’s no real difference, except that when you use the repo, you are trusting it indefinitely, whereas if you download the deb directly, you are only trusting it once.
Using the repo is less secure, because it opens you to future attacks against the repo itself.
Https is vulnerable to loads of attack. That’s why we sign packages.
You’re downloading the signing key over HTTPS either way, from the same server. That’s the common point of failure.
That’s why you download the key from multiple distinct domains from multiple distinct locations using multiple distinct devices and veryify their fingerprints match. If the key/fingerprint is only available on one domain, open a bug report with the maintainer.