| 1 | //! Trust anchors for the cloud facts channel. |
| 2 | //! |
| 3 | //! Keys are pinned in the binary. The Supabase `facts_key` table and the |
| 4 | //! website mirror (`web/lib/cloud-facts/keys.ts`) are informational; a facts |
| 5 | //! envelope is accepted only when its signature verifies under an `Active` key |
| 6 | //! listed here. `web/scripts/check-cloud-facts.mjs` fails CI if this table and |
| 7 | //! the TypeScript mirror diverge. |
| 8 | //! |
| 9 | //! Rotation (two-release rule): pin the new key here → ship → sign with both |
| 10 | //! keys (`sigs`) → mark the old key `Retired` → ship → drop it. Compromise: |
| 11 | //! revoke every release signed by the key server-side, ship a binary without |
| 12 | //! the key. There is deliberately no in-band "distrust this key" message. |
| 13 | |
| 14 | /// Domain separator prefixed to every signed message. |
| 15 | /// |
| 16 | /// Message = `DOMAIN || key_id || 0x00 || payload_bytes`. |
| 17 | pub const DOMAIN: &[u8] = b"codewhale-facts/v1\0"; |
| 18 | |
| 19 | /// Transport envelope version this client understands. |
| 20 | pub const ENVELOPE_VERSION: u64 = 1; |
| 21 | |
| 22 | /// Highest signed-payload `schema_version` this client understands. Newer |
| 23 | /// payloads are rejected as `SchemaTooNew` and the bundled facts stay in use. |
| 24 | pub const SUPPORTED_SCHEMA_VERSION: u32 = 1; |
| 25 | |
| 26 | /// Hard cap on the decoded payload; enforced before any crypto runs. |
| 27 | pub const MAX_PAYLOAD_BYTES: usize = 512 * 1024; |
| 28 | |
| 29 | /// Hard cap on the raw envelope document (payload base64 + metadata). |
| 30 | pub const MAX_ENVELOPE_BYTES: usize = 768 * 1024; |
| 31 | |
| 32 | /// Whether a pinned key may still authenticate new releases. |
| 33 | #[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| 34 | pub enum KeyStatus { |
| 35 | /// Accepts signatures. |
| 36 | Active, |
| 37 | /// Still listed so `/status` can name it, but no longer accepted. |
| 38 | Retired, |
| 39 | } |
| 40 | |
| 41 | /// One pinned Ed25519 verifying key. |
| 42 | #[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| 43 | pub struct TrustedKey { |
| 44 | /// `cwf-<label>`; also part of the signed message. |
| 45 | pub key_id: &'static str, |
| 46 | /// Raw 32-byte Ed25519 public key. |
| 47 | pub public_key: [u8; 32], |
| 48 | pub status: KeyStatus, |
| 49 | } |
| 50 | |
| 51 | /// Pinned production trust anchors. |
| 52 | /// |
| 53 | /// A shipped binary can only trust a key it was compiled with — there is no |
| 54 | /// in-band command that installs or widens trust, and `CODEWHALE_CLOUD_FACTS_PATH` |
| 55 | /// verifies against this same table, so a local envelope is no escape hatch. |
| 56 | /// Adding a key here is therefore a release-gated decision, and the matching |
| 57 | /// entry in `web/lib/cloud-facts/keys.ts` must stay byte-identical: |
| 58 | /// `check:facts` fails when the two tables diverge. |
| 59 | /// |
| 60 | /// Tests inject their own fixture keys; no fixture signature establishes |
| 61 | /// production trust. |
| 62 | pub const TRUSTED_KEYS: &[TrustedKey] = &[TrustedKey { |
| 63 | // Approved 2026-09-10. Private half held by the founder outside any |
| 64 | // repository; only this public anchor is committed. |
| 65 | key_id: "cwf-2026-09", |
| 66 | public_key: [ |
| 67 | 229, 221, 108, 200, 133, 179, 185, 249, 210, 78, 85, 107, 124, 85, 91, 236, 39, 143, 28, |
| 68 | 190, 129, 220, 233, 125, 216, 136, 82, 215, 148, 26, 6, 133, |
| 69 | ], |
| 70 | status: KeyStatus::Active, |
| 71 | }]; |
| 72 | |
| 73 | /// Look up a pinned key by id. |
| 74 | #[must_use] |
| 75 | pub fn trusted_key<'a>(keys: &'a [TrustedKey], key_id: &str) -> Option<&'a TrustedKey> { |
| 76 | keys.iter().find(|key| key.key_id == key_id) |
| 77 | } |
| 78 |