For long-term secrets, you can use L<RAND_priv_bytes(3)> instead.
This method does not provide 'better' randomness, it uses the same type of CSPRNG.
The intention behind using a dedicated CSPRNG exclusively for long-term secrets is
-that none of its output should be visible to an attacker (e.g used as salt value),
-in order to reveal as little information as possible about its internal state.
+that none of its output should be visible to an attacker (e.g used as salt value),
+in order to reveal as little information as possible about its internal state.
In the rare case where the default implementation does not satisfy your special
requirements, there are two options: