# modifiziert
sub auth_header {
...
    for (@order) {
        next unless defined $resp{$_};

        if ( $_ eq 'nc' ) {
            push(@pairs, "$_=" . qq($resp{$_}));
        }
        else {
            push(@pairs, "$_=" . qq("$resp{$_}"));
        }
    }

    my $auth_value  = "Digest " . join(", ", @pairs);
    return $auth_value;
}