KnownHosts.cs :  » Network-Clients » SharpSSH » Tamir » SharpSsh » jsch » examples » C# / CSharp Open Source

using System;
using System.IO;
using System.Windows.Forms;

/* KnownHosts.cs
 * ====================================================================
 * The following example was posted with the original JSch java library,
 * and is translated to C# to show the usage of SharpSSH JSch API
 * ====================================================================
 * */
namespace Tamir.SharpSsh.jsch.examples{
  /// <summary>
  /// This program will demonstrate the 'known_hosts' file handling.
  /// You will be asked username, hostname, a path for 'known_hosts' and passwd. 
  /// If everything works fine, you will get the shell prompt.
  /// In current implementation, jsch only reads 'known_hosts' for checking
  /// and does not modify it.
  /// </summary>
  public class KnownHosts
  {
    public static void Main(String[] arg)
    {
      try
      {
        //Get the "known hosts" filename from the user
        Console.WriteLine("Please select your 'known_hosts' from the poup window...");
        String file = InputForm.GetFileFromUser("Choose your known_hosts(ex. ~/.ssh/known_hosts)");
        Console.WriteLine("You chose "+file+".");
        //Create a new JSch instance
        JSch jsch=new JSch();
        //Set the known hosts file
        jsch.setKnownHosts(file);        

        //Get the KnownHosts repository from JSchs
        HostKeyRepository hkr=jsch.getHostKeyRepository();

        //Print all known hosts and keys
        HostKey[] hks=hkr.getHostKey();
        HostKey hk;
        if(hks!=null)
        {
          Console.WriteLine();
          Console.WriteLine("Host keys in "+hkr.getKnownHostsRepositoryID()+":");
          for(int i=0; i<hks.Length; i++)
          {
            hk=hks[i];
            Console.WriteLine(hk.getHost()+" "+
              hk.getType()+" "+
              hk.getFingerPrint(jsch));
          }
          Console.WriteLine("");
        }

        //Now connect to the remote server...

        //Prompt for username and server host
        Console.WriteLine("Please enter the user and host info at the popup window...");
        String host = InputForm.GetUserInput
          ("Enter username@hostname",
          Environment.UserName+"@localhost");
        String user=host.Substring(0, host.IndexOf('@'));
        host=host.Substring(host.IndexOf('@')+1);

        //Create a new SSH session
        Session session=jsch.getSession(user, host, 22);

        // username and password will be given via UserInfo interface.
        UserInfo ui=new MyUserInfo();
        session.setUserInfo(ui);

        //Connect to remote SSH server
        session.connect();

        //Print the host key info
        //of the connected server:
        hk=session.getHostKey();
        Console.WriteLine("HostKey: "+
          hk.getHost()+" "+
          hk.getType()+" "+
          hk.getFingerPrint(jsch));
      
        //Open a new Shell channel on the SSH session
        Channel channel=session.openChannel("shell");

        //Redirect standard I/O to the SSH channel
        channel.setInputStream(Console.OpenStandardInput());
        channel.setOutputStream(Console.OpenStandardOutput());

        //Connect the channel
        channel.connect();

        Console.WriteLine("-- Shell channel is connected using the {0} cipher", 
          session.getCipher());

        //Wait till channel is closed
        while(!channel.isClosed())
        {
          System.Threading.Thread.Sleep(500);
        }

        //Disconnect from remote server
        channel.disconnect();
        session.disconnect();
      }
      catch(Exception e)
      {
        Console.WriteLine(e);
      }
    }

    /// <summary>
    /// A user info for getting user data
    /// </summary>
    public class MyUserInfo : UserInfo
    {
      /// <summary>
      /// Holds the user password
      /// </summary>
      private String passwd;

      /// <summary>
      /// Returns the user password
      /// </summary>
      public String getPassword(){ return passwd; }

      /// <summary>
      /// Prompt the user for a Yes/No input
      /// </summary>
      public bool promptYesNo(String str)
      {
        return InputForm.PromptYesNo(str);
      }
      
      /// <summary>
      /// Returns the user passphrase (passwd for the private key file)
      /// </summary>
      public String getPassphrase(){ return null; }

      /// <summary>
      /// Prompt the user for a passphrase (passwd for the private key file)
      /// </summary>
      public bool promptPassphrase(String message){ return true; }

      /// <summary>
      /// Prompt the user for a password
      /// </summary>
      public bool promptPassword(String message)
      {
        passwd=InputForm.GetUserInput(message, true);
        return true;
      }

      /// <summary>
      /// Shows a message to the user
      /// </summary>
      public void showMessage(String message)
      {
        InputForm.ShowMessage(message);
      }
    }
  }
}