grasshopper_encrypt_block(&c->c.encrypt_round_keys,
(grasshopper_w128_t *)iv, (grasshopper_w128_t *)out, &c->c.buffer);
grasshopper_append128((grasshopper_w128_t *)out, (grasshopper_w128_t *)in);
grasshopper_encrypt_block(&c->c.encrypt_round_keys,
(grasshopper_w128_t *)iv, (grasshopper_w128_t *)out, &c->c.buffer);
grasshopper_append128((grasshopper_w128_t *)out, (grasshopper_w128_t *)in);