A set of flags describing TLS certification validation. This can be used to set which validation steps to perform (eg, with g_tls_client_connection_set_validation_flags()), or to describe why a particular certificate was rejected (eg, in accept-certificate).
The signing certificate authority is not known.
The certificate does not match the expected identity of the site that it was retrieved from.
The certificate's activation time is still in the future
The certificate has expired
The certificate has been revoked according to the gio.TlsConnection's certificate revocation list.
The certificate's algorithm is considered insecure.
Some other error occurred validating the certificate
the combination of all of the above flags