.github/workflows/slsa-build.yml

name: SLSA L1 Build Provenance (signed)

# SPDX-License-Identifier: Apache-2.0
# © 2026 Lutar, Stephen P. — SZL Holdings · ORCID 0009-0001-0110-4173
# Doctrine v11 LOCKED 749/14/163 · sovereign-default
#
# SLSA L1 honest: generate signed build provenance on a hosted GitHub
# Actions builder for every release tag, using the official
# slsa-framework/slsa-github-generator reusable workflow. The provenance
# attestation is signed via Sigstore (Fulcio keyless + Rekor) and attached to
# the release. SZL claims SLSA L1 (honest); L2 requires isolated builder not yet configured.
# Concepts only — no third-party logos or trademarks.

on:
  push:
    tags: ["v*", "*.*.*"]
  release:
    types: [published]
  workflow_dispatch:

permissions: read-all

jobs:
  # 1. Build the release artifact and record its digest (hosted runner).
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    outputs:
      digest: ${{ steps.hash.outputs.digest }}
      artifact: ${{ steps.pack.outputs.artifact }}
    steps:
      - name: Harden runner
        uses: step-security/harden-runner@9af89fc71515a100421586dfdb3dc9c984fbf411 # v2.19.4
        with:
          egress-policy: audit

      - name: Checkout
        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3

      - name: Pack source release artifact
        id: pack
        run: |
          NAME="${GITHUB_REPOSITORY##*/}-${GITHUB_REF_NAME}.tar.gz"
          git archive --format=tar.gz -o "$NAME" HEAD
          echo "artifact=$NAME" >> "$GITHUB_OUTPUT"

      - name: Compute artifact digest (base64 sha256 set)
        id: hash
        run: |
          echo "digest=$(sha256sum '${{ steps.pack.outputs.artifact }}' | base64 -w0)" >> "$GITHUB_OUTPUT"

      - name: Upload artifact for release
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: release-artifact
          path: ${{ steps.pack.outputs.artifact }}
          if-no-files-found: error

  # 2. Generate signed SLSA provenance (reusable hosted-builder workflow).
  provenance:
    needs: [build]
    permissions:
      actions: read       # read the workflow run for provenance
      id-token: write     # Sigstore keyless signing (Fulcio/OIDC)
      contents: write     # attach provenance to the release
    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@v2.1.0
    with:
      base64-subjects: "${{ needs.build.outputs.digest }}"
      provenance-name: "${{ needs.build.outputs.artifact }}.intoto.jsonl"
      upload-assets: true