> I believe you that token uploads will continue to be possible, but it seems likely that in a couple of years trusted publishing & attestations will be effectively required for all but the tiniest project.
That's what I think will happen.
> And maybe that's a good thing? I'm not against security, and supply chain attacks are real.
The problem is the attestation is only for part of the supply chain. You can say "this artifact was built with GitHub Actions" and that's it.
If I'm using Gitea and Drone or self-hosted GitLab, I'm not going to get trusted publisher attestations even though I stick to best practices everywhere.
Contrast that with someone that runs as admin on the same PC they use for pirating software, has a passwordless GPG key that signs all their commits, and pushes to GitHub (Actions) for builds and deployments. That person will have more "verified" badges than me and, because of that, would out-compete me if we had similar looking projects.
The point being that knowing how part of the supply chain works isn't sufficient. Security considerations need to start the second your finger touches the power button on your PC. The build tool at the end of the development process is the tip of the iceberg and shouldn't be relied on as a primary indicator of trust. It can definitely be part of it, but only a small part IMO.
The only way a trusted publisher (aka platform) can reliably attest to the security of the supply chain is if they have complete control over your development environment which would include a boot-locked PC without admin rights, forced MFA with a trustworthy (aka their) authenticator, and development happening 100% on their cloud platform or with tools that come off a safe-list.
Even if everyone gets onboard with that idea it's not going to stop bad actors. It'll be exactly the same as bad actors setting up companies and buying EV code signing certificates. Anyone with enough money to buy into the platform will immediately be viewed with a baseline of trust that isn't justified.