doc: add a note to the RAND_get0_ calls indicating how to set the DRBG type.
The type needs to be set before the DRBGs are created.
@@ -57,9 +57,14 @@ During initialization, it is possible to change the reseed interval
and reseed time interval.
It is also possible to exchange the reseeding callbacks entirely.
+To set the type of DRBG that will be instantiated, use the
+L<RAND_set_DRBG_type(3)> call before accessing the random number generation
+infrastructure.
+
=head1 SEE ALSO
-L<EVP_RAND(3)>
+L<EVP_RAND(3)>,
+L<RAND_set_DRBG_type(3)>
=head1 HISTORY
