public_key ~secret_key returns the public key of the specifed secret key.
val sign : secret_key:string->?public_key:string-> string -> string
sign ~secret_key ~public_key ~message returns the Ed25519 cryptographic signature of message using secret_key. If public_key is not given it is recomputed, doubling the execution time.
val check : signature:string->public_key:string-> string -> bool
check ~signature ~public_key ~message checks that signature of message is genuine for the secret key of public_key.
WARNING: This function does NOT run in constant time. See the Monocypher manual for more information.