EVP_sha1(), EVP_dss(), EVP_dss1(), EVP_mdc2() and EVP_ripemd160() return
pointers to the corresponding EVP_MD structures.
-B<EVP_get_digestbyname>, B<EVP_get_digestbynid> and B<EVP_get_digestbyobj>
+EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj()
return either an B<EVP_MD> structure or NULL if an error occurs.
=head1 NOTES