@deftypefun {int} {gnutls_x509_dn_oid_known} (const char * @var{oid})
@var{oid}: holds an Object Identifier in a null terminated string

This function will inform about known DN OIDs. This is useful since
functions like @code{gnutls_x509_crt_set_dn_by_oid()}  use the information
on known OIDs to properly encode their input. Object Identifiers
that are not known are not encoded by these functions, and their
input is stored directly into the ASN.1 structure. In that case of
unknown OIDs, you have the responsibility of DER encoding your
data.

@strong{Returns:} 1 on known OIDs and 0 otherwise.
@end deftypefun