only fail due to a memory allocation error.
ASN1_INTEGER_to_BN() and ASN1_ENUMERATED_to_BN() return a B<BIGNUM> structure
-of NULL if an error occurs. They can fail if the pased type is incorrect
+of NULL if an error occurs. They can fail if the passed type is incorrect
(due to programming error) or due to a memory allocation failure.
=head1 SEE ALSO