@deftypefun {int} {gnutls_x509_crl_get_extension_oid} (gnutls_x509_crl_t @var{crl}, unsigned @var{indx}, void * @var{oid}, size_t * @var{sizeof_oid})
@var{crl}: should contain a @code{gnutls_x509_crl_t}  type

@var{indx}: Specifies which extension OID to send, use (0) to get the first one.

@var{oid}: a pointer to store the OID (may be null)

@var{sizeof_oid}: initially holds the size of  @code{oid} 

This function will return the requested extension OID in the CRL.
The extension OID will be stored as a string in the provided
buffer.

@strong{Returns:} On success, @code{GNUTLS_E_SUCCESS}  (0) is returned, otherwise a
negative error code in case of an error.  If your have reached the
last extension available @code{GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE} 
will be returned.

@strong{Since:} 2.8.0
@end deftypefun