Builds both WebAuthn ceremonies on top of the library, with real cryptography
proven in tests rather than stubbed:
- PasskeyCeremonyStore: server-authoritative, single-use challenge state in the
nonceCache pool. The client's challenge copy is never trusted, and consume()
deletes before verifying so a replay cannot retry the same challenge.
- PasskeyManager: registration and login ceremonies. Library types are confined
to this class and PasskeyCeremonyFactory. Failures return null rather than
distinguishing unknown-credential from bad-signature, so the endpoint is not
an enumeration oracle.
- PasskeyTestHelper: builds genuinely valid ceremonies (real P-256 keypair,
COSE key, signed authenticatorData, CBOR attestation object).
- PasskeyRealCryptoSpikeTest: proves registration and assertion verify, that
http:// origins are refused (D4), that challenges and rpIdHash are bound, and
that a synchronised passkey with a constant zero counter can log in repeatedly.
