jsch and running “sudo su -”

Question

Using jsch

when i run the following cmd 'sudo su -' the program hangs

[TestNG] Running:
C:\Users\brian.crosby\AppData\Local\Temp\testng-eclipse-952620154\testng-customsuite.xml
[root@tbx2-toy-1 ~]# 

It looks like the "sudo su -" worked becasue the output states "[root@tbx2-toy-1 ~]#" but when i send it another cmd it is unresponsive.

heres the code:

package com.linux;

import java.io.InputStream;
import org.testng.annotations.*;
import com.jcraft.jsch.*;
import com.thoughtworks.selenium.*;

public class LinuxConnection extends SeleneseTestBase{

    String host = null;
    private StringBuilder strFileData;
    String randomFileName = null;

    public String getFileData() {
        return strFileData.toString();
    }
    public String getRandomFileName() {
        return randomFileName;
    }

    public LinuxConnection() {
        strFileData = new StringBuilder();
    }

    @Test
    public void createUpdateTBX2FileData(String command)throws Exception {

        try {
            JSch jsch = new JSch();
            host = "brian-crosby@************.net"; 

            String user = host.substring(0, host.indexOf('@'));
            host = host.substring(host.indexOf('@') + 1);

            Session session = jsch.getSession(user, host, 22);

            UserInfo ui = new MyUserInfo();
            session.setUserInfo(ui);
            session.connect();

            ChannelExec channel = (ChannelExec)session.openChannel("exec");
            ((ChannelExec)channel).setPty(true);
            ((ChannelExec) channel).setCommand(command);

            ((ChannelExec) channel).setErrStream(System.err);

            InputStream in = channel.getInputStream();
            channel.connect();

            byte[] tmp = new byte[2048];

            while (in.read(tmp, 0, 2048) > 0) {
                String str = new String(tmp);
                strFileData.append(str);
                System.out.println(strFileData);
            }
            in.close();
            channel.disconnect();
            session.disconnect();
        } catch (Exception e) {
            System.out.println(e);
        }
    }

    public static class MyUserInfo implements UserInfo {

        public String getPassword() {
            return "********";
        }

        public boolean promptYesNo(String str) {
            str = "Yes";
            return true;
        }

        String passwd;

        public String getPassphrase() {
            return null;
        }

        public boolean promptPassphrase(String message) {
            return true;
        }

        public boolean promptPassword(String message) {
            passwd = "*******"; 
            return true;
        }

        public void showMessage(String message) {

        }
    }

}

Here is where i am sending the cmds:

package com.linux;

import org.testng.annotations.*;

public class testLinuxConnection {

    @Test
    public void testLinux() throws Exception{
        LinuxConnection obj = new LinuxConnection();
        String command = "touch tester1.txt; sudo su -; rm tester1.txt;";
        obj.createUpdateTBX2FileData(command);  
    }
}

Again i have spent hours on google trying to find a solution but was unsuccessful

Any help is appreciated

Answer 1

You are code is missing the rest of the code needed for this to run. You need to initialize the type of channel you need out of the initialized session object. Since you need to be able to run more than one command after each other, you need a Shell type channel:

You should check JSch's examples (i.e. Shell.java), here it is for a quick reference:

/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/**
 * This program enables you to connect to sshd server and get the shell prompt.
 *   $ CLASSPATH=.:../build javac Shell.java 
 *   $ CLASSPATH=.:../build java Shell
 * You will be asked username, hostname and passwd. 
 * If everything works fine, you will get the shell prompt. Output will
 * be ugly because of lacks of terminal-emulation, but you can issue commands.
 *
 */
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;

public class Shell{
  public static void main(String[] arg){

    try{
      JSch jsch=new JSch();

      //jsch.setKnownHosts("/home/foo/.ssh/known_hosts");

      String host=null;
      if(arg.length>0){
        host=arg[0];
      }
      else{
        host=JOptionPane.showInputDialog("Enter username@hostname",
                                         System.getProperty("user.name")+
                                         "@localhost"); 
      }
      String user=host.substring(0, host.indexOf('@'));
      host=host.substring(host.indexOf('@')+1);

      Session session=jsch.getSession(user, host, 22);

      String passwd = JOptionPane.showInputDialog("Enter password");
      session.setPassword(passwd);

      UserInfo ui = new MyUserInfo(){
        public void showMessage(String message){
          JOptionPane.showMessageDialog(null, message);
        }
        public boolean promptYesNo(String message){
          Object[] options={ "yes", "no" };
          int foo=JOptionPane.showOptionDialog(null, 
                                               message,
                                               "Warning", 
                                               JOptionPane.DEFAULT_OPTION, 
                                               JOptionPane.WARNING_MESSAGE,
                                               null, options, options[0]);
          return foo==0;
        }

        // If password is not given before the invocation of Session#connect(),
        // implement also following methods,
        //   * UserInfo#getPassword(),
        //   * UserInfo#promptPassword(String message) and
        //   * UIKeyboardInteractive#promptKeyboardInteractive()

      };

      session.setUserInfo(ui);

      // It must not be recommended, but if you want to skip host-key check,
      // invoke following,
      // session.setConfig("StrictHostKeyChecking", "no");

      //session.connect();
      session.connect(30000);   // making a connection with timeout.

      Channel channel=session.openChannel("shell");

      // Enable agent-forwarding.
      //((ChannelShell)channel).setAgentForwarding(true);

      channel.setInputStream(System.in);
      /*
      // a hack for MS-DOS prompt on Windows.
      channel.setInputStream(new FilterInputStream(System.in){
          public int read(byte[] b, int off, int len)throws IOException{
            return in.read(b, off, (len>1024?1024:len));
          }
        });
       */

      channel.setOutputStream(System.out);

      /*
      // Choose the pty-type "vt102".
      ((ChannelShell)channel).setPtyType("vt102");
      */

      /*
      // Set environment variable "LANG" as "ja_JP.eucJP".
      ((ChannelShell)channel).setEnv("LANG", "ja_JP.eucJP");
      */

      //channel.connect();
      channel.connect(3*1000);
    }
    catch(Exception e){
      System.out.println(e);
    }
  }

  public static abstract class MyUserInfo
                          implements UserInfo, UIKeyboardInteractive{
    public String getPassword(){ return null; }
    public boolean promptYesNo(String str){ return false; }
    public String getPassphrase(){ return null; }
    public boolean promptPassphrase(String message){ return false; }
    public boolean promptPassword(String message){ return false; }
    public void showMessage(String message){ }
    public String[] promptKeyboardInteractive(String destination,
                                              String name,
                                              String instruction,
                                              String[] prompt,
                                              boolean[] echo){
      return null;
    }
  }
}