I see people talking about doas saying it’s just like sudo but with less features. I’m just wondering if there is any situation where you should use doas or if it’s just personal preference.
On the one hand, doas is simpler. Less code means less bugs, and lower chance someone manages to hack it and gain admin rights. On the other hand, sudo is more popular, and so has a lot more people double-checking its security. Ultimately, I don’t think it matters - when someone unauthorized gains admin rights, usually it’s not due to bug in sudo or doas, but other problems.
I use doas just because. It’s not necessary at all, but it can’t hurt either (I think). It might be a bit more secure (fewer features -> fewer code -> fewer bugs -> fewer vulnerabilities, need to give password more often). Kinda cool if you want more minimalism for fun (I replaced startx with sx…)
You can change the config so you don’t need to give the password every time.
Adding the persist option only requires it once every few minutes within a terminal session.
https://manpages.debian.org/bullseye/doas/doas.conf.5.en.html#persist
Doas is more secure, sudo has had a few critical vulnerabilities in the past, because the codebase is much larger. Sudo has like a million features that most people don’t need, but they significantly increase attack surface.
Doas is more secure, sudo has had a few critical vulnerabilities in the past, because
… it’s newer. You wanted to say “it’s newer.” It has nowhere near the history, and looks better because it’s newer.
Please, now, trot out the “use sudo if you’re old” memes, because we grew that skin extra thick over the systemd counter-hate.
doas, afaik, was originally made for FreeBSD, so some of its features aren’t compatible with/haven’t been implemented for Linux. That may or may not be an important issue for you to consider.
When I thought about this question, I decided to ditch both sudo and doas entirely. I am certain this is an unpopular opinion, but I preferred setting up a granular permission + user system instead, and keeping root privileges for only a handful of use cases (primarily for system updates and package installations).
For anything else, a dedicated user is created, and given only permissions to do that exact thing only. Many of these users have no shell access at all, and for the ones that do, I use a password manager so I don’t have to memorize passwords for all of these users.
Did you know that you can configure sudo to only grant access to specific programs?
Yes I did, and that’s a very good point. What sudo does not allow me to do is grant a user access to modify or read specific files or directories. I can get both that and access to executing specific programs using a users/groups permission system.
Another thing I don’t like about sudo is that you end up using the same password for everything, which is also the password for logging in. Putting higher privileges behind my same login password opens me to a single point of failure.
Why would a system update need privileges? What is the privileged action in pulling and applying updates your distro ships?
I mean, that’s one of the things that definitely needs permissions, right? You’re overwriting system config and executables for all users on your system. Otherwise a malicious actor could just replace firewall configs, or embed malicious code into your executables. If not /bin and /etc what else should need privileges?
On a mutable distro maybe but also no. You need to update your system, always. The updates come from the distro, and you only invoke your privileged package manager to do these changes for you. Its not privileged.
If a malicious actor is able to replace package repos that your package manager uses, for example an infected server in the same network, this would be the only way to inject arbitrary stuff by using dnf update or rpm-ostree update.
Installing software and updating the already existing is very different.
The short answer is that my distro did not let me do this easily. But that was for good reason.
A system update would require too many privileges that it would be almost indistinguishable from root.
Currently, every user I have is restricted in what files it has access to. A system update user would need access to so many files, including install locations of all binaries, and non-binary installation paths of all current and future programs I install (some package installs modify /var, many modify /etc, and so on).
This user will also have access to all these programs, down to system applications. It can trivially break a permission system I come up with.
It may be possible to restrict system updates to a user, but it would be such a powerful user that its not really worth it.
Does the user have that access? In my case with rpm-ostree they can just execute 2 commands rpm-ostree refresh-md (get updates) and rpm-ostree update. rpm-ostree rebase is used for system upgrades afaik, that one needs a password.
What is the privileged action in pulling and applying updates your distro ships
Tell me again how you want to write system files with a non-admin account, and I’m going to show you my friend Lumpy, who will walk all over your machine so fucking fast. Fuck that, Lumpy’s a genius. One of his underlings (he manages now) will do it on a lunch break.
