ossl_hash_context
struct ossl_hash_context ctx;
struct ossl_hash_context ictx;
struct ossl_hash_context octx;
sizeof(struct ossl_hash_context), "ossl_hash_context too small");
_Static_assert(sizeof(SHA_CTX) <= sizeof(struct ossl_hash_context),
_Static_assert(sizeof(SHA256_CTX) <= sizeof(struct ossl_hash_context),
_Static_assert(sizeof(SHA512_CTX) <= sizeof(struct ossl_hash_context),