nonce_cache_key
struct nonce_cache_key* nk = (struct nonce_cache_key*)k;
size_t key_size = sizeof(struct nonce_cache_key)
struct nonce_cache_key *k1 = m1, *k2 = m2;
struct nonce_cache_key* nk = (struct nonce_cache_key*)k;
struct nonce_cache_key* k =
(struct nonce_cache_key*)calloc(1, sizeof(*k));
struct nonce_cache_key k;