PyPI now supports digital attestations

I have a bit of uneasiness about how this is heavily pushing GitHub actions as the correct way to publish to PyPI. I had to check PEP740 to make sure it was not directly supported by Microsoft.

> The generation and publication of attestations happens by default, and no changes are necessary for projects that meet all of these conditions: publish from GitHub Actions; via Trusted Publishing; and use the pypa/gh-action-pypi-publish action to publish.

If you then click on "The manual way" it adds a big disclaimer:

> STOP! You probably don't need this section; it exists only to provide some internal details about how attestation generation and uploading work. If you're an ordinary user, it is strongly recommended that you use one of the official workflows described above.

Where the only official workflow is "Use GitHub Actions".

I guess I am an idealist but as a maintainer this falls short of my expectations for the openness of Python and PyPI.

> Where the only official workflow is "Use GitHub Actions".

The standard behind this (PEP 740) supports anything that can be used with Trusted Publishing[1]. That includes GitLab, Google Cloud, ActiveState, and can include any other OIDC IdP if people make a good case for including it.

It's not tied to Microsoft or GitHub in any particular way. The only reason it emphasizes GitHub Actions is because that's where the overwhelming majority of automatic publishing traffic comes from, and because it follows a similar enablement pattern as Trusted Publishing did (where we did GitHub first, followed by GitLab and other providers).

[1]: https://docs.pypi.org/trusted-publishers/

I get that, that's why I didn't go "This is Embrace Extend Extinguish", but as constructive feedback I would recommend softening the language and to replace:

> STOP! You probably don't need this section;

In https://docs.pypi.org/attestations/producing-attestations/#t...

Perhaps also add a few of the providers you listed as well?

> The only reason it emphasizes GitHub Actions is because that's where the overwhelming majority of automatic publishing traffic comes from

GitHub being popular is a self-reinforcing process, if GitHub is your first class citizen for something as crucial as trusted publishing then projects on GitHub will see a higher adoption and become the de-facto "secure choice".

> but as constructive feedback I would recommend softening the language and to replace:

I can soften it, but I think you're reading it excessively negatively: that warning is there to make sure people don't try to do the fiddly, error-prone cryptographic bits if they don't need to. It's a numerical fact that most project owners don't need that section, since most are either using manual API tokens or are publishing via GitHub Actions.

> Perhaps also add a few of the providers you listed as well?

They'll be added when they're enabled. Like I said in the original comment, we're using a similar enablement pattern as happened with Trusted Publishing: GitHub was enabled first because it represents the majority of publishing traffic, followed by GitLab and the others.

> GitHub being popular is a self-reinforcing process, if GitHub is your first class citizen for something as crucial as trusted publishing then projects on GitHub will see a higher adoption and become the de-facto "secure choice".

I agree, but I don't think this is PyPI's problem to solve. From a security perspective, PyPI should prioritize the platforms where the traffic is.

(I'll note that GitLab has been supported by Trusted Publishing for a while now, and they could make the publishing workflow more of a first class citizen, the way it is on GHA.)

> error-prone cryptographic bits if they don't need to

They can't. Because you wouldn't accept their key anyway.

I think you're missing something. The key in question is a short-lived ECDSA key that lives inside a publishing workflow and is destroyed after signing; neither GitHub nor the Sigstore CA generates a signing key for you.

PyPI will accept any key bound to an identity, provided we know how to verify that identity. Right now that means we accept Trusted Publishing identities, and GitHub identities in particular, since that's where the overwhelming majority of Python package publishing traffic comes from. Like what happened Trusted Publishing, this will be expanded to other identities (like GitLab repositories) as we roll it out.