nn_get_random_len
ATTRIBUTE_WARN_UNUSED_RET int nn_get_random_len(nn_t out, u16 len);
ret = nn_get_random_len(&r, m_msb_fixed.wlen * WORD_BYTES); EG(ret, err);
ret = nn_get_random_len(&r, (u16)(m_msb_fixed.wlen * WORD_BYTES)); EG(ret, err);
ret = nn_get_random_len(&mask, NN_MAX_BYTE_LEN); EG(ret, err);
ret = nn_get_random_len(out, len);
ret = nn_get_random_len(&z, (hsize / 4)); EG(ret, err);
ret = nn_get_random_len(&z, (hsize / 4)); EG(ret, err);
ret = nn_get_random_len(&(priv_key->x), (digest_size / 2)); EG(ret, err);