@deftypefun {int} {gnutls_x509_crl_get_number} (gnutls_x509_crl_t @var{crl}, void * @var{ret}, size_t * @var{ret_size}, unsigned int * @var{critical})
@var{crl}: should contain a @code{gnutls_x509_crl_t}  type

@var{ret}: The place where the number will be copied

@var{ret_size}: Holds the size of the result field.

@var{critical}: will be non-zero if the extension is marked as critical
(may be null)

This function will return the CRL number extension.  This is
obtained by the CRL Number extension field (2.5.29.20).

@strong{Returns:} On success, @code{GNUTLS_E_SUCCESS}  (0) is returned, otherwise a
negative error code in case of an error.

@strong{Since:} 2.8.0
@end deftypefun