ocrypto_ecdsa_p521_sign_hash()

int ocrypto_ecdsa_p521_sign_hash	(	uint8_t	sig[132],
		const uint8_t	hash[64],
		const uint8_t	sk[66],
		const uint8_t	ek[66]
	)

ECDSA P-521 signature generation from SHA512 hash.

The message hash hash is signed using the secret key sk and the ephemeral session key ek. The signature is put into sig.

Parameters

[out]	sig	Generated signature.
	hash	Input hash.
	sk	Secret key.
	ek	Session key. Must be pre-filled with random data.

Return values

0	If ek is a valid session key.
-1	Otherwise.

Remarks

To generate a valid signature use the following code pattern:

do get_random(ek); while (ocrypto_ecdsa_p521_sign_hash(sig, hash, sk, ek));