



@deftypefun {void} {gnutls_session_set_verify_output_function} (gnutls_session_t @var{session}, gnutls_verify_output_function * @var{func})
@var{session}: is a @code{gnutls_x509_trust_list_t}  type.

@var{func}: is the callback function

This function sets a callback to be called when the peer's certificate
chain has to be verified and full path to the trusted root has to be
printed.

The callback's function prototype is defined in `x509.h':
int (*callback)(
gnutls_x509_crt_t cert,
gnutls_x509_crt_t issuer,
gnutls_x509_crl_t crl,
unsigned int verification_output);

If the callback function is provided then gnutls will call it, in the
certificate verification procedure.
To verify the certificate chain and print its path uptp the trusted root,
functions such as @code{gnutls_certificate_verify_peers()} ,
@code{gnutls_x509_trust_list_verify_crt()} , and @code{gnutls_x509_trust_list_verify_crt2()} 
can be used. The callback is set in @code{_gnutls_verify_crt_status()}  and
@code{_gnutls_pkcs11_verify_crt_status()} .

@strong{Since:} 3.7.0
@end deftypefun
