implement cert utility to fulcio/tsa

[ianhundere]

Description

As a Liatrio Engineer:

I would like to following the advice of the sigstore maintainer(s) to add our poc cert utility to the Fulcio and TSA repos (other svcs?)

So that the process for creating such certs is more streamlined and achievable for those in the Sigstore community

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Acceptance Criteria

• Add (PR accepted + merged) to the Fulcio repository (and possibly TSA repo) including:
  • the correct cert specs:
    • Fulcio
    • RFC3161
  • leverage any packages in the respective repo:
  • tests
  • any other fb/requests the community might have:

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Additional Context

Originally opened here, it was met with positive feedback, but it was also cross posted to the scaffolding repo whereby one of the main maintainers showed great interest in implementing such a utility, but suggested it might best live in the Fulcio/TSA repo(s):

• light tool to create/sign (via kms) fulcio/tsa certs (ca, leaf etc) sigstore/scaffolding#1334

Will followup on their feedback and continue work on this.

[ianhundere]

waiting to hear back on consensus

[ianhundere]

following up
sigstore/scaffolding#1334 (comment)

[ianhundere]

got an answer, will begin when back from PTO

sigstore/scaffolding#1334 (comment)

[ianhundere]

issues created in each repo:

• light tool to create/sign (via kms) certs (ca, leaf etc) sigstore/timestamp-authority#886
• light tool to create/sign (via kms) certs (ca, leaf etc) sigstore/fulcio#1869