FxSsh

FxSsh is a lightweight SSH server side application as SSH reinforcement of GitCandy.

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Nuget

PM> Install-Package FxSsh

Sample code

static int windowWidth, windowHeight;

static void Main(string[] args)
{
    var server = new SshServer();
    server.AddHostKey("ssh-rsa", "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");
    server.AddHostKey("ssh-dss", "BwIAAAAiAABEU1MyAAQAAG+6KQWB+crih2Ivb6CZsMe/7NHLimiTl0ap97KyBoBOs1amqXB8IRwI2h9A10R/v0BHmdyjwe0c0lPsegqDuBUfD2VmsDgrZ/i78t7EJ6Sb6m2lVQfTT0w7FYgVk3J1Deygh7UcbIbDoQ+refeRNM7CjSKtdR+/zIwO3Qub2qH+p6iol2iAlh0LP+cw+XlH0LW5YKPqOXOLgMIiO+48HZjvV67pn5LDubxru3ZQLvjOcDY0pqi5g7AJ3wkLq5dezzDOOun72E42uUHTXOzo+Ct6OZXFP53ZzOfjNw0SiL66353c9igBiRMTGn2gZ+au0jMeIaSsQNjQmWD+Lnri39n0gSCXurDaPkec+uaufGSG9tWgGnBdJhUDqwab8P/Ipvo5lS5p6PlzAQAAACqx1Nid0Ea0YAuYPhg+YolsJ/ce");
    server.ConnectionAccepted += server_ConnectionAccepted;

    server.Start();

    Task.Delay(-1).Wait();
}

static void server_ConnectionAccepted(object sender, Session e)
{
    Console.WriteLine("Accepted a client.");

    e.ServiceRegistered += e_ServiceRegistered;
    e.KeysExchanged += e_KeysExchanged;
}

private static void e_KeysExchanged(object sender, KeyExchangeArgs e)
{
    foreach (var keyExchangeAlg in e.KeyExchangeAlgorithms)
    {
        Console.WriteLine("Key exchange algorithm: {0}", keyExchangeAlg);
    }
}

static void e_ServiceRegistered(object sender, SshService e)
{
    var session = (Session)sender;
    Console.WriteLine("Session {0} requesting {1}.",
        BitConverter.ToString(session.SessionId).Replace("-", ""), e.GetType().Name);

    if (e is UserauthService)
    {
        var service = (UserauthService)e;
        service.Userauth += service_Userauth;
    }
    else if (e is ConnectionService)
    {
        var service = (ConnectionService)e;
        service.CommandOpened += service_CommandOpened;
        service.EnvReceived += service_EnvReceived;
        service.PtyReceived += service_PtyReceived;
        service.TcpForwardRequest += service_TcpForwardRequest;
        service.WindowChange += Service_WindowChange;
    }
}

static void Service_WindowChange(object sender, WindowChangeArgs e)
{
    // DEMO MiniTerm not support change window size
}

static void service_TcpForwardRequest(object sender, TcpRequestArgs e)
{
    Console.WriteLine("Received a request to forward data to {0}:{1}", e.Host, e.Port);

    var allow = true;  // func(e.Host, e.Port, e.AttachedUserauthArgs);

    if (!allow)
        return;

    var tcp = new TcpForwardService(e.Host, e.Port, e.OriginatorIP, e.OriginatorPort);
    e.Channel.DataReceived += (ss, ee) => tcp.OnData(ee);
    e.Channel.CloseReceived += (ss, ee) => tcp.OnClose();
    tcp.DataReceived += (ss, ee) => e.Channel.SendData(ee);
    tcp.CloseReceived += (ss, ee) => e.Channel.SendClose();
    tcp.Start();
}

static void service_PtyReceived(object sender, PtyArgs e)
{
    Console.WriteLine("Request to create a PTY received for terminal type {0}", e.Terminal);
    windowWidth = (int)e.WidthChars;
    windowHeight = (int)e.HeightRows;
}

static void service_EnvReceived(object sender, EnvironmentArgs e)
{
    Console.WriteLine("Received environment variable {0}:{1}", e.Name, e.Value);
}

static void service_Userauth(object sender, UserauthArgs e)
{
    Console.WriteLine("Client {0} fingerprint: {1}.", e.KeyAlgorithm, e.Fingerprint);

    e.Result = true;
}

static void service_CommandOpened(object sender, CommandRequestedArgs e)
{
    Console.WriteLine($"Channel {e.Channel.ServerChannelId} runs {e.ShellType}: \"{e.CommandText}\".");

    var allow = true;  // func(e.ShellType, e.CommandText, e.AttachedUserauthArgs);

    if (!allow)
        return;

    if (e.ShellType == "shell")
    {
        // requirements: Windows 10 RedStone 5, 1809
        // also, you can call powershell.exe
        var terminal = new Terminal("cmd.exe", windowWidth, windowHeight);

        e.Channel.DataReceived += (ss, ee) => terminal.OnInput(ee);
        e.Channel.CloseReceived += (ss, ee) => terminal.OnClose();
        terminal.DataReceived += (ss, ee) => e.Channel.SendData(ee);
        terminal.CloseReceived += (ss, ee) => e.Channel.SendClose(ee);

        terminal.Run();
    }
    else if (e.ShellType == "exec")
    {
        var parser = new Regex(@"(?<cmd>git-receive-pack|git-upload-pack|git-upload-archive) \'/?(?<proj>.+)\.git\'");
        var match = parser.Match(e.CommandText);
        var command = match.Groups["cmd"].Value;
        var project = match.Groups["proj"].Value;

        var git = new GitService(command, project);

        e.Channel.DataReceived += (ss, ee) => git.OnData(ee);
        e.Channel.CloseReceived += (ss, ee) => git.OnClose();
        git.DataReceived += (ss, ee) => e.Channel.SendData(ee);
        git.CloseReceived += (ss, ee) => e.Channel.SendClose(ee);

        git.Start();
    }
    else if (e.ShellType == "subsystem")
    {
        // do something more
    }
}

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License

The MIT license