Releases & verification

Releases live on the GitHub Releases page. Each is cut from a v* git tag by the release workflow, which builds every artifact reproducibly, hashes it, and signs the manifest.

What a release contains

• Eight firmware images — rs-key-<tag>-<flavor>.uf2, the cross product of the build flags (up-button × advertise-pqc × fips-profile):

  flavor	flags	use
  default	touch	the normal build — start here
  pqc	+ advertise-pqc	advertises ML-DSA-44 in getInfo (breaks old Firefox)
  fips	+ fips-profile	the locked FIPS-style policy (guides/fips.md)
  fips-pqc	+ both
  no-touch	presence off	test builds — the automated suites can’t press a button
  no-touch-pqc / no-touch-fips / no-touch-fips-pqc	…	test variants

  All eight present the default RS-Key USB identity (0x1209:0x0001). For the YubiKey-interop identity, build VIDPID=Yubikey5 yourself (build.md).

• SHA256SUMS — a checksum for every image and the SBOM.

• SHA256SUMS.cosign.bundle — a keyless cosign signature of SHA256SUMS (sigstore/Fulcio; the signer is the release workflow’s GitHub OIDC identity, logged in Rekor).

• rs-key-<tag>-sbom.cdx.json — a CycloneDX software bill of materials for the firmware’s dependency tree.

The images are UNSIGNED for secure boot. The cosign signature attests who built them, not the boot seal. On a secure-boot device you seal an image with your own key before flashing — nix run .#flash does it, or see production.md. The reproducibility claim is about the unsigned payload (a seal is signer-specific and not reproducible by a third party).

Verify a download

Grab the images you want plus SHA256SUMS and SHA256SUMS.cosign.bundle.

# 1. the checksums file is authentic (keyless cosign — needs cosign >= 2.0)
cosign verify-blob \
  --bundle SHA256SUMS.cosign.bundle \
  --certificate-identity-regexp '^https://github\.com/TheMaxMur/RS-Key/\.github/workflows/release\.yml@refs/tags/v.*' \
  --certificate-oidc-issuer 'https://token.actions.githubusercontent.com' \
  SHA256SUMS

# 2. the images match the (now-trusted) checksums
sha256sum -c SHA256SUMS

Both must pass. Step 1 proves SHA256SUMS was produced by this repo’s release workflow; step 2 ties each .uf2 (and the SBOM) to it.

Verify the build is reproducible

The images are bit-for-bit reproducible per platform, per flake.lock, so you can rebuild them yourself and compare — no need to trust the published binary:

git checkout <tag>
nix build .#firmware              # the default flavor (others: .#firmware-fips, …)
sha256sum result/firmware.uf2     # compare against SHA256SUMS for rs-key-<tag>-default.uf2

A match on Linux reproduces the CI-built artifact exactly. (Cross-platform identity — macOS vs Linux — is not guaranteed; the canonical bytes are the Linux ones the workflow publishes.)