Comment by __MatrixMan__
2 years ago
You're talking sense, but this is due diligence for a developer, not for an operating system or a package manager.
You're free to map your package definitions to the commits they contain and verify any signatures that you find there, but that process will have nothing to do with whether other people have signed the instructions that your machine follows to fetch and build the contents of that commit.
Sure I could write a lot of tooling to try and do this sort of basic verification manually in Nix every single time i pin a new package, but at that point why am I using nix over distros that have native support for maintainer level supply chain integrity?
Compare to the Arch model where all official packages must be signed with keys belonging to a reasonably well vetted web of trust.
Developers outside the web of trust that want to contribute yolo unsigned packages to Arch still can, but those must go into AUR where users must opt-in to and manually review each individual untrusted/unsigned package.
https://wiki.archlinux.org/title/Pacman/Package_signing
Nix decided to have the yolo AUR model by default, with no method to elect to use only signed packages, because signing and web of trust are not even supported at all, even optionally.
This is wildly irresponsible given how many people use Nix today.
Nix is two steps forward in deterministic, immutable, and unprivileged package management, and one giant leap backwards in supply chain integrity.
This is why we cannot have nice things.
Nix is two steps forward in these ways because they chose to focus on making things composable and repeatable instead of being curators of quality and trustworthiness.
One magical thing about Nix is that there's a very small divide between managing to install software in the first place and creating an artifact that others can use for the same purpose.
Because of this, practically every NixOS user has their configuration in source control--we're basically each building our own Linux distro with only packages that we trust. Some of us probably sign those commits too.
The ecosystem is useful because it encourages this kind if participation. Having a list of privileged maintainers would interrupt this.
It's unsurprising that a group of people who has worked quite hard to make this possible would be uninterested in creating a scheme whereby they are now responsible for determining which of their users creations is legitimate. Nix attracts users who are interested in that sort of thing, so let it be a userspace problem.
If you want to curate a list of trustworthy packages and work with their developers to set up a chain of trust that starts in a yubikey extends to a signature in a flake output, then I'll help because that sounds like useful work, but I wish you would stop criticizing a brick for not already being a house.
My criticism is not so much on NixOS itself. If it wants to be a fun, composable, and easy to work on with minimal participation friction, fair enough. The yolo approach to contribution integrity has clearly resulted in fast development of ideas that might have been unable to grow in other distros.
I suppose where my, perhaps misdirected, anxiety comes from is that I run a security consulting company and see NixOS being used as-is in high risk applications, to compile binaries responsible for protecting peoples property or safety, and on the workstations of production engineering teams. Places where it has no business being because supply chain integrity is a non goal.
Maybe you are right though, and the answer is not trying to add supply chain security practices onto a community that does not want them, but to create a security focused fork of that distro that can inherit all that great community work and be a drop-in replacement for NixOS in environments where supply chain security is of critical importance.
I tried and failed to get buy-in for even -optional- expression integrity support back in 2018 and gave up on nix after that. https://github.com/NixOS/rfcs/pull/34
I did prototype a git multisig solution in the years following that though: https://git.distrust.co/public/supsig https://git.distrust.co/public/git-sig
It is already being used in production by some as nothing better exists atm.
A security focused Nix fork that imports, reviews, and git-sig (or similar) signs commits from NixOS and has signature verification built into the package manager, is probably the only way forward, and I would be willing to ally with others interested in this.
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