RS-Key v0.1.0

0.1.0 — 2026-06-13

First public release — an open-source security-key firmware for the Raspberry Pi
RP2350 (Cortex-M33), a behavioral reimplementation of the AGPL-3.0 pico-keys
family that keeps the "enterprise" features in the open tree.

Security keys / protocols

• FIDO2 / WebAuthn / U2F — passkeys (discoverable credentials), second-factor,
  ssh -t ed25519-sk, hmac-secret and largeBlobs; user presence gated on the
  BOOTSEL button (the default touch build).
• OpenPGP card 3.4 — sign / decrypt / authenticate; EC (Ed25519, NIST, brainpool)
  and on-card RSA keygen (2048/3072/4096) accelerated across both cores.
• PIV — X.509 slots, attestation, the Yubico management extensions; works
  through PKCS#11 / OpenSC and the OS-native stacks.
• OATH (YKOATH) — TOTP / HOTP credential store.
• Yubico OTP — slot programming and challenge-response over CCID, plus the
  HID-keyboard typing path.

Enterprise features, in the open tree

• forceChangePin enforcement, a SHA-256-chained signed audit trail, an opt-in
  fips-profile, organizational attestation (import key + chain), and host-side
  fleet inventory / verification / offboarding tooling.

Hardening

• Secure boot + anti-rollback (RP2350 OTP), keys sealed under an OTP-burned
  device root, and an at-rest soft-lock of the FIDO seed.

Tooling

• The rsk CLI and the rsk-tui ratatui dashboard; guided primary + backup
  device pairing; secure-boot key-rotation tooling. Run without the dev shell via
  nix run .#rsk, .#rsk-tui, and a one-command flasher .#flash.

USB identity

• The default build presents this project's own pid.codes identity
  (0x1209:0x0001, "RS-Key Security Key") — not a YubiKey masquerade. An opt-in
  VIDPID=Yubikey5 flavor borrows the YubiKey identity for ykman / Yubico
  Authenticator interop.

Assurance

• 39 fuzz targets, Kani proofs, a Miri pass, power-cut torture, bit-reproducible
  nix build images (per platform, per flake.lock), and a hardware-verified
  interop matrix (docs/interop.md).

Release artifacts

• Eight firmware flavors (up-button × advertise-pqc × fips-profile), each a
  reproducible unsigned .uf2 — on a secure-boot device, seal it with your
  own key before flashing (nix run .#flash, or see
  docs/production.md).
• SHA256SUMS over every artifact, a keyless cosign
  signature of it, and a CycloneDX SBOM. See
  docs/releases.md to verify a download.

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Verify a download: https://github.com/TheMaxMur/RS-Key/blob/v0.1.0/docs/releases.md