ARGON2_PREHASH_SEED_LENGTH
blockhash, ARGON2_PREHASH_SEED_LENGTH);
blockhash, ARGON2_PREHASH_SEED_LENGTH);
uint8_t blockhash[ARGON2_PREHASH_SEED_LENGTH];
ARGON2_PREHASH_SEED_LENGTH - ARGON2_PREHASH_DIGEST_LENGTH);
OPENSSL_cleanse(blockhash, ARGON2_PREHASH_SEED_LENGTH);