@deftypefun {void} {gnutls_handshake_set_private_extensions} (gnutls_session_t @var{session}, int @var{allow})
@var{session}: is a @code{gnutls_session_t}  type.

@var{allow}: is an integer (0 or 1)

This function will enable or disable the use of private cipher
suites (the ones that start with 0xFF).  By default or if  @code{allow} is 0 then these cipher suites will not be advertised nor used.

Currently GnuTLS does not include such cipher-suites or
compression algorithms.

Enabling the private ciphersuites when talking to other than
gnutls servers and clients may cause interoperability problems.
@end deftypefun