Request privileged rights and keep this with C# in Ubuntu Linux

Question

I'm writing a tool that can be used to manage the virtual host a web server on Ubuntu. As for many of the features I need privileged rights, I look for ways to achieve this.

Currently I realize that with "gksu" or "gksudo". This also works. The problem is that the user is prompted for any activity that requires privileged rights to enter his password. Is it possible to retrieve this password only once and remember for the rest of the duration of the program? Is there another way to implement this?

    public void OnToogledVirtualHost(object o, ToggledArgs args)
    {
        VirtualHost host = (VirtualHost)store.GetNode(new TreePath(args.Path));
        host.Enabled = !host.Enabled;
        Process process = new Process();
        process.StartInfo.UseShellExecute = false;

        if (host.Enabled)
        {
            process.StartInfo.FileName = "gksu";
            process.StartInfo.Arguments = "a2ensite " + System.IO.Path.GetFileName(host.FilePath);
        }
        else
        {
            process.StartInfo.FileName = "gksu";
            process.StartInfo.Arguments = "a2dissite " + System.IO.Path.GetFileName(host.FilePath);
        }
        process.Start();
    }

Answer 1

Thanks for the useful approaches. Yesterday I arrived at a solution of the problem, which I have enclosed in a static class. First, a distinction is made between normal and privilligierten processes.

Whenever a process needs to be run with elevated privileges, I check if I know the user's password already. If not, I'll get it (gksudo -p) and store it in memory. Now I can execute commands with privilligierten rights. The stored password is then transferred via the standard input (sudo -S).

What do you think? Do you have any safety concerns?

public static class SystemProcess
{
    private static string output;
    private static string error;
    private static string password;

    public static void Start (string filename, string arguments)
    {
        ProcessStartInfo startInfo = SystemProcess.Prepare(filename, arguments);

        using (Process process = Process.Start(startInfo)) {
            SystemProcess.output = process.StandardOutput.ReadToEnd();
            SystemProcess.error = process.StandardError.ReadToEnd();

            process.WaitForExit();
        }
    }

    public static void StartPrivileged (string filename, string arguments)
    {
        ProcessStartInfo startInfo;

        if (SystemProcess.password == default(string))
        {
            startInfo = SystemProcess.Prepare("gksudo", "-p true -D 'MyApplication'");

            using (Process process = Process.Start(startInfo)) {
                SystemProcess.password = process.StandardOutput.ReadToEnd();
                process.WaitForExit();
            }
        }

        startInfo = SystemProcess.Prepare("sudo", "-S " + filename + " " + arguments);

        using (Process process = Process.Start(startInfo)) {
            process.StandardInput.WriteLine(SystemProcess.password);
            SystemProcess.output = process.StandardOutput.ReadToEnd();
            SystemProcess.error = process.StandardError.ReadToEnd();

            process.WaitForExit();
        }
    }

    private static ProcessStartInfo Prepare (string filename, string arguments)
    {
        ProcessStartInfo startInfo = new ProcessStartInfo (filename, arguments);

        startInfo.RedirectStandardError = true;
        startInfo.RedirectStandardOutput = true;
        startInfo.RedirectStandardInput = true;
        startInfo.UseShellExecute = false;

        return startInfo;
    }

    public static string Output {
        get {
            return SystemProcess.output;
        }
    }

    public static string Error {
        get {
            return SystemProcess.error;
        }
    }
}