1 /* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
2 /**
3  * This program will demonstrate the port forwarding like option -L of
4  * ssh command; the given port on the local host will be forwarded to
5  * the given remote host and port on the remote side.
6  *   $ CLASSPATH=.:../build javac PortForwardingL.java
7  *   $ CLASSPATH=.:../build java PortForwardingL
8  * You will be asked username, hostname, port:host:hostport and passwd.
9  * If everything works fine, you will get the shell prompt.
10  * Try the port on localhost.
11  *
12  */
13 import com.jcraft.jsch.*;
14 import java.awt.*;
15 import javax.swing.*;
16 
17 public class PortForwardingL{
main(String[] arg)18   public static void main(String[] arg){
19 
20     int lport;
21     String rhost;
22     int rport;
23 
24     try{
25       JSch jsch=new JSch();
26 
27       String host=null;
28       if(arg.length>0){
29         host=arg[0];
30       }
31       else{
32         host=JOptionPane.showInputDialog("Enter username@hostname",
33                                          System.getProperty("user.name")+
34                                          "@localhost");
35       }
36       String user=host.substring(0, host.indexOf('@'));
37       host=host.substring(host.indexOf('@')+1);
38 
39       Session session=jsch.getSession(user, host, 22);
40 
41       String foo=JOptionPane.showInputDialog("Enter -L port:host:hostport",
42 					     "port:host:hostport");
43       lport=Integer.parseInt(foo.substring(0, foo.indexOf(':')));
44       foo=foo.substring(foo.indexOf(':')+1);
45       rhost=foo.substring(0, foo.indexOf(':'));
46       rport=Integer.parseInt(foo.substring(foo.indexOf(':')+1));
47 
48       // username and password will be given via UserInfo interface.
49       UserInfo ui=new MyUserInfo();
50       session.setUserInfo(ui);
51 
52       session.connect();
53 
54       //Channel channel=session.openChannel("shell");
55       //channel.connect();
56 
57       int assinged_port=session.setPortForwardingL(lport, rhost, rport);
58       System.out.println("localhost:"+assinged_port+" -> "+rhost+":"+rport);
59     }
60     catch(Exception e){
61       System.out.println(e);
62     }
63   }
64 
65   public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
getPassword()66     public String getPassword(){ return passwd; }
promptYesNo(String str)67     public boolean promptYesNo(String str){
68       Object[] options={ "yes", "no" };
69       int foo=JOptionPane.showOptionDialog(null,
70              str,
71              "Warning",
72              JOptionPane.DEFAULT_OPTION,
73              JOptionPane.WARNING_MESSAGE,
74              null, options, options[0]);
75        return foo==0;
76     }
77 
78     String passwd;
79     JTextField passwordField=(JTextField)new JPasswordField(20);
80 
getPassphrase()81     public String getPassphrase(){ return null; }
promptPassphrase(String message)82     public boolean promptPassphrase(String message){ return true; }
promptPassword(String message)83     public boolean promptPassword(String message){
84       Object[] ob={passwordField};
85       int result=
86 	  JOptionPane.showConfirmDialog(null, ob, message,
87 					JOptionPane.OK_CANCEL_OPTION);
88       if(result==JOptionPane.OK_OPTION){
89 	passwd=passwordField.getText();
90 	return true;
91       }
92       else{ return false; }
93     }
showMessage(String message)94     public void showMessage(String message){
95       JOptionPane.showMessageDialog(null, message);
96     }
97     final GridBagConstraints gbc =
98       new GridBagConstraints(0,0,1,1,1,1,
99                              GridBagConstraints.NORTHWEST,
100                              GridBagConstraints.NONE,
101                              new Insets(0,0,0,0),0,0);
102     private Container panel;
promptKeyboardInteractive(String destination, String name, String instruction, String[] prompt, boolean[] echo)103     public String[] promptKeyboardInteractive(String destination,
104                                               String name,
105                                               String instruction,
106                                               String[] prompt,
107                                               boolean[] echo){
108       panel = new JPanel();
109       panel.setLayout(new GridBagLayout());
110 
111       gbc.weightx = 1.0;
112       gbc.gridwidth = GridBagConstraints.REMAINDER;
113       gbc.gridx = 0;
114       panel.add(new JLabel(instruction), gbc);
115       gbc.gridy++;
116 
117       gbc.gridwidth = GridBagConstraints.RELATIVE;
118 
119       JTextField[] texts=new JTextField[prompt.length];
120       for(int i=0; i<prompt.length; i++){
121         gbc.fill = GridBagConstraints.NONE;
122         gbc.gridx = 0;
123         gbc.weightx = 1;
124         panel.add(new JLabel(prompt[i]),gbc);
125 
126         gbc.gridx = 1;
127         gbc.fill = GridBagConstraints.HORIZONTAL;
128         gbc.weighty = 1;
129         if(echo[i]){
130           texts[i]=new JTextField(20);
131         }
132         else{
133           texts[i]=new JPasswordField(20);
134         }
135         panel.add(texts[i], gbc);
136         gbc.gridy++;
137       }
138 
139       if(JOptionPane.showConfirmDialog(null, panel,
140                                        destination+": "+name,
141                                        JOptionPane.OK_CANCEL_OPTION,
142                                        JOptionPane.QUESTION_MESSAGE)
143          ==JOptionPane.OK_OPTION){
144         String[] response=new String[prompt.length];
145         for(int i=0; i<prompt.length; i++){
146           response[i]=texts[i].getText();
147         }
148 	return response;
149       }
150       else{
151         return null;  // cancel
152       }
153     }
154   }
155 }
156