1 /* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
2 /**
3  * This program will demonstrate the stream forwarding. The given Java
4  * I/O streams will be forwared to the given remote host and port on
5  * the remote side.  It is simmilar to the -L option of ssh command,
6  * but you don't have to assign and open a local tcp port.
7  *   $ CLASSPATH=.:../build javac StreamForwarding.java
8  *   $ CLASSPATH=.:../build java StreamForwarding
9  * You will be asked username, hostname, host:hostport and passwd.
10  * If everything works fine, System.in and System.out streams will be
11  * forwared to remote port and you can send messages from command line.
12  *
13  */
14 import com.jcraft.jsch.*;
15 import java.awt.*;
16 import javax.swing.*;
17 
18 public class StreamForwarding{
main(String[] arg)19   public static void main(String[] arg){
20     int port;
21 
22     try{
23       JSch jsch=new JSch();
24 
25       String host=null;
26       if(arg.length>0){
27         host=arg[0];
28       }
29       else{
30         host=JOptionPane.showInputDialog("Enter username@hostname",
31                                          System.getProperty("user.name")+
32                                          "@localhost");
33       }
34       String user=host.substring(0, host.indexOf('@'));
35       host=host.substring(host.indexOf('@')+1);
36 
37       Session session=jsch.getSession(user, host, 22);
38 
39       // username and password will be given via UserInfo interface.
40       UserInfo ui=new MyUserInfo();
41       session.setUserInfo(ui);
42       session.connect();
43 
44       String foo=JOptionPane.showInputDialog("Enter host and port",
45 						 "host:port");
46       host=foo.substring(0, foo.indexOf(':'));
47       port=Integer.parseInt(foo.substring(foo.indexOf(':')+1));
48 
49       System.out.println("System.{in,out} will be forwarded to "+
50 			 host+":"+port+".");
51       Channel channel = session.getStreamForwarder(host, port);
52       // InputStream in = channel.getInputStream();
53       // OutpuStream out = channel.getOutputStream();
54       channel.setInputStream(System.in);
55       channel.setOutputStream(System.out);
56       channel.connect(1000);
57     }
58     catch(Exception e){
59       System.out.println(e);
60     }
61   }
62 
63   public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
getPassword()64     public String getPassword(){ return passwd; }
promptYesNo(String str)65     public boolean promptYesNo(String str){
66       Object[] options={ "yes", "no" };
67       int foo=JOptionPane.showOptionDialog(null,
68              str,
69              "Warning",
70              JOptionPane.DEFAULT_OPTION,
71              JOptionPane.WARNING_MESSAGE,
72              null, options, options[0]);
73        return foo==0;
74     }
75 
76     String passwd;
77     JTextField passwordField=(JTextField)new JPasswordField(20);
78 
getPassphrase()79     public String getPassphrase(){ return null; }
promptPassphrase(String message)80     public boolean promptPassphrase(String message){ return true; }
promptPassword(String message)81     public boolean promptPassword(String message){
82       Object[] ob={passwordField};
83       int result=
84 	  JOptionPane.showConfirmDialog(null, ob, message,
85 					JOptionPane.OK_CANCEL_OPTION);
86       if(result==JOptionPane.OK_OPTION){
87 	passwd=passwordField.getText();
88 	return true;
89       }
90       else{ return false; }
91     }
showMessage(String message)92     public void showMessage(String message){
93       JOptionPane.showMessageDialog(null, message);
94     }
95     final GridBagConstraints gbc =
96       new GridBagConstraints(0,0,1,1,1,1,
97                              GridBagConstraints.NORTHWEST,
98                              GridBagConstraints.NONE,
99                              new Insets(0,0,0,0),0,0);
100     private Container panel;
promptKeyboardInteractive(String destination, String name, String instruction, String[] prompt, boolean[] echo)101     public String[] promptKeyboardInteractive(String destination,
102                                               String name,
103                                               String instruction,
104                                               String[] prompt,
105                                               boolean[] echo){
106       panel = new JPanel();
107       panel.setLayout(new GridBagLayout());
108 
109       gbc.weightx = 1.0;
110       gbc.gridwidth = GridBagConstraints.REMAINDER;
111       gbc.gridx = 0;
112       panel.add(new JLabel(instruction), gbc);
113       gbc.gridy++;
114 
115       gbc.gridwidth = GridBagConstraints.RELATIVE;
116 
117       JTextField[] texts=new JTextField[prompt.length];
118       for(int i=0; i<prompt.length; i++){
119         gbc.fill = GridBagConstraints.NONE;
120         gbc.gridx = 0;
121         gbc.weightx = 1;
122         panel.add(new JLabel(prompt[i]),gbc);
123 
124         gbc.gridx = 1;
125         gbc.fill = GridBagConstraints.HORIZONTAL;
126         gbc.weighty = 1;
127         if(echo[i]){
128           texts[i]=new JTextField(20);
129         }
130         else{
131           texts[i]=new JPasswordField(20);
132         }
133         panel.add(texts[i], gbc);
134         gbc.gridy++;
135       }
136 
137       if(JOptionPane.showConfirmDialog(null, panel,
138                                        destination+": "+name,
139                                        JOptionPane.OK_CANCEL_OPTION,
140                                        JOptionPane.QUESTION_MESSAGE)
141          ==JOptionPane.OK_OPTION){
142         String[] response=new String[prompt.length];
143         for(int i=0; i<prompt.length; i++){
144           response[i]=texts[i].getText();
145         }
146 	return response;
147       }
148       else{
149         return null;  // cancel
150       }
151     }
152   }
153 }
154 
155 
156