@deftypefun {int} {gnutls_certificate_allocate_credentials} (gnutls_certificate_credentials_t *      @var{res})
@var{res}: is a pointer to a @code{gnutls_certificate_credentials_t}  structure.

This structure is complex enough to manipulate directly thus this
helper function is provided in order to allocate it.

@strong{Returns:} @code{GNUTLS_E_SUCCESS}  on success, or an error code.
@end deftypefun