For the other functions, 1 is returned for success, 0 on error.
The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
+=head1 WARNING
+
+The inputs must be reduced modulo B<m>, otherwise the result will be
+outside the expected range.
+
=head1 SEE ALSO
L<bn(3)|bn(3)>, L<err(3)|err(3)>, L<BN_add(3)|BN_add(3)>,