Extract the COSE public key from a WebAuthn attestation object. The attestation object is CBOR-encoded with an authData field that contains the credential public key in COSE_Key format starting at byte offset 55 + credIdLen.
authData
Extract the COSE public key from a WebAuthn attestation object. The attestation object is CBOR-encoded with an
authDatafield that contains the credential public key in COSE_Key format starting at byte offset 55 + credIdLen.