ARGON2_PREHASH_DIGEST_LENGTH
store32(blockhash + ARGON2_PREHASH_DIGEST_LENGTH, 0);
store32(blockhash + ARGON2_PREHASH_DIGEST_LENGTH + 4, l);
store32(blockhash + ARGON2_PREHASH_DIGEST_LENGTH, 1);
tmp = ARGON2_PREHASH_DIGEST_LENGTH;
(ARGON2_PREHASH_DIGEST_LENGTH + (2 * sizeof(uint32_t)))
OPENSSL_cleanse(blockhash + ARGON2_PREHASH_DIGEST_LENGTH,
ARGON2_PREHASH_SEED_LENGTH - ARGON2_PREHASH_DIGEST_LENGTH);