if (partial_hash_compute(hash_alg, opad, p_state_buf + *p_state_len)) {
memset(ipad, 0, block_size);
memset(opad, 0, block_size);
if (partial_hash_compute(hash_alg, opad, p_state_buf + *p_state_len)) {
memset(ipad, 0, block_size);
memset(opad, 0, block_size);