@deftypefun {int} {gnutls_x509_crq_get_dn_by_oid} (gnutls_x509_crq_t @var{crq}, const char * @var{oid}, unsigned @var{indx}, unsigned int @var{raw_flag}, void * @var{buf}, size_t * @var{buf_size})
@var{crq}: should contain a gnutls_x509_crq_t type

@var{oid}: holds an Object Identifier in a null terminated string

@var{indx}: In case multiple same OIDs exist in the RDN, this specifies
which to get. Use (0) to get the first one.

@var{raw_flag}: If non-zero returns the raw DER data of the DN part.

@var{buf}: a pointer to a structure to hold the name (may be @code{NULL} )

@var{buf_size}: initially holds the size of  @code{buf} 

This function will extract the part of the name of the Certificate
request subject, specified by the given OID. The output will be
encoded as described in RFC2253. The output string will be ASCII
or UTF-8 encoded, depending on the certificate data.

Some helper macros with popular OIDs can be found in gnutls/x509.h
If raw flag is (0), this function will only return known OIDs as
text. Other OIDs will be DER encoded, as described in RFC2253 --
in hex format with a '\#' prefix.  You can check about known OIDs
using @code{gnutls_x509_dn_oid_known()} .

@strong{Returns:} @code{GNUTLS_E_SHORT_MEMORY_BUFFER}  if the provided buffer is
not long enough, and in that case the * @code{buf_size} will be
updated with the required size.  On success 0 is returned.
@end deftypefun