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Comment by btrask | Hacker News Reader

I was trying to download Linux securely a month or so ago. It's actually embarrassingly difficult to do. The only two distros that did it right (that I could find) are Debian and Alpine Linux. The rest (including Mint and Ubuntu) had hashes (usually MD5) or GPG keys served over HTTP.

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I noticed last year that ubuntu.com - despite being the source from which most people download Ubuntu .isos - has no HTTPS capability and doesn't offer any checksums or gpg signatures on their download page. I believe you can find gpg signatures if you scratch around on their ftp server, but it is ridiculous to assume users will do this (especially when Ubuntu is trying to be a user-friendly distro).

Anyway, as a result I ended up emailing their webmaster asking why Ubuntu.com has no SSL cert. and I haven't heard anything back yet. I think it is pretty poor that a company like Canonical can have such a flagrant disregard for basic security practices, especially when it likes to market Ubuntu as a 'secure' OS.

It's a bit convoluted. Follow this guide - https://help.ubuntu.com/community/VerifyIsoHowto

If you are running Ubuntu then you already have signing key (run apt-key list), otherwise you can compare the full fingerprint with the one printed in terminal output in the guide that's hosted on https.

It's on HTTPS, but it's also a Wiki that anyone can edit. This is the most recent change: https://help.ubuntu.com/community/VerifyIsoHowto?action=diff...

If you can think of any improvements Debian could make, please do suggest them via bug reports or on the mailing list. If you would like to work on fixing some of our issues, here are the ones we know about:

https://wiki.debian.org/Hardening/RepoAndImages

Debian is already outstanding in this regard (and others)!

One minor suggestion would be to provide ISO hashes over HTTPS. It's just as secure as using GPG with fingerprints sent over HTTPS, and it's a lot easier.

The fingerprints (https://www.debian.org/CD/verify) could also be made more prominent (perhaps put on the main download page).

Thanks again!

Maybe in a GPG-signed release email add magnet URLs for the official torrents.

This is kind of in 'No magnet: links for bittorrent downloads on SSL'

Fedora publishes GPG signed SHA256's of the iso's. eg. https://dl.fedoraproject.org/pub/fedora/linux/releases/23/Wo...

Thanks! Fedora was one I didn't try (to install; I use it all the time). However there's still no way to use RPMFusion: http://rpmfusion.org/keys

Maybe there's something I'm missing?

Arch Linux has PGP signatures and is over https, as well as torrents which should be pretty reliable https://www.archlinux.org/download/

RPMFusion isn't considered part of Fedora. Yes, it would be nice if RPMFusion served hashes securely.

Arch Linux has HTTPS mirrors and provide their GPG signature on HTTPS site.

What I don't get about publishing the hashes, etc... if they are serving up tampered .iso files, why wouldn't they also change the website to serve the appropriate hashes for the hacked isos? For the verification to work I would think it needs to be PGP-signed and you should have the public key in advance.

Are torrents more secure? I usually use the torrents option.

Yes they are. No risk of man-in-the-middle with torrents.

Why is that a problem? If the hash is signed and the public key is trusted shouldn't that be secure?

Because someone can do a man-in-the-middle attack and intercept the right hash and replace it with another one. And how do you verify that the public key is trusted for the first time?

I was under the impression that you can have your key signed by a generally trusted CA.

GPG has no central CAs, but relies on a "web of trust" situation. In reality, there's no one central that everyone trusts, so unless the keys are signed by some individual you personally trust, you're down to being reliant on getting valid keys.

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