sub validate_session{
# ---- usage
# if( validate_session( $sessionDataToValidate ) ){ print "Session Ok!\n"; }
# ----
# prüfen, ob gültige sid: a)muster b)haltbarkeit c)valid
# my $session = ($uid * $uniq) / 7 . 'XY' . time() . 'XY' . $uniq . 'XY' . rand(1) . 'XY' . $uid;
    my $session = @_;
    my $return = 0;
    if( $session =~ m/\[d{16}\.]XY\d{10}XY\d{15}\[d{15}\.]XY\d*/ ){ #Muster ok?
        if( (split /XY/, $session)[1] > time() - SESSION_TIME ){ #gültig? (Zeit)
            if( ((split /XY/, $session)[0] * 7) / (split /XY/, $session)[-1] == (split /XY/, $session)[-3] ){ #valid? (user)
                $return = 1;
            }
        }
    }
    return $return;
}