Module jwks 

The public half of a signing_key as a JSON Web Key Set (Phase 24.5).

A service that signs tokens publishes its public keys at a jwks_uri, and a rotation needs the old and the new key listed together for as long as tokens signed by the old one are still in flight - which is why the entry has a first-class “previous key” slot. This turns what the vault holds (a PEM or a JWK) into the document a verifier fetches.

Only public material is ever produced. A JWK that arrives with private members (d, p, q, dp, dq, qi, k) has them stripped, and a PEM that is a private key is refused rather than derived from: publishing the wrong half is the one mistake a key set cannot take back. Nothing is verified or generated here; keys are re-encoded, never operated on.

PEM PUBLIC KEY (SPKI) is read for RSA, EC (P-256, P-384, P-521), Ed25519 and X25519; RSA PUBLIC KEY (PKCS#1) for RSA. A key without a kid gets its RFC 7638 thumbprint, which is what a verifier would compute for it anyway.

Functions

entry_jwk

One entry of the key set: the key with its kid, alg and use.

key_set

The key set for a signing_key entry: the current key and, while a rotation is open, the previous one. None for a part that is empty.

public_jwk

A public JWK from either spelling the vault might hold, with no private members.

thumbprint

The RFC 7638 thumbprint of a public JWK, which is the kid a verifier would derive and the one used when the entry names none.