Support for SBOMs in (signed) in-toto attestations

[puerco]

What would you like to be added:

We should support reading and writing SBOMs in in-toto attestations. bom should be able to read SBOMs wrapped in in-toto attestations, even if they are wrapped in a DSSE Envelope or in sigstore bundles.

This requirement does not include signing and verifying the attestation signature.

Why is this needed:

Writing and reading the SBOM data from in-toto attestations will make bom a better companion to other supply chain tools by taking care of encoding/decoding the JSON matryoshka.

[k8s-triage-robot]

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/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle rotten
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle rotten