{
my $auth_module;
sub _driver {
    my @auth_modes = split(/\s+/, MT->config->AuthenticationModule);
    foreach my $auth_mode (@auth_modes) {
        my $auth_module_name = 'MT::Auth::' . $auth_mode;
        eval 'require ' . $auth_module_name;
        if (my $err = $@) {
            die (MT->translate("Bad AuthenticationModule config '[_1]': [_2]", $auth_mode, $err));
        }
        my $auth_module = $auth_module_name->new;
        die $auth_module_name->errstr
            if (!$auth_module || (ref(\$auth_module) eq 'SCALAR'));
        return $auth_module;
    }
    die(MT->translate("Bad AuthenticationModule config"));
}

sub _handle {
    my $method = shift;
    my $mod = $auth_module ||= _driver();
    return undef unless $mod->can($method);
    $mod->$method(@_);
}

sub release {
    undef $auth_module;
}
}