com.jscape.inet.telnetssh

Class TelnetSsh

java.lang.Object

com.jscape.inet.telnet.Telnet

com.jscape.inet.telnetssh.TelnetSsh

All Implemented Interfaces:

java.io.Serializable

public class TelnetSsh
extends Telnet

Implements the basic functionality of a Telnet client as defined in RFC 854 tunnelling all data thru a secure SSH connection. This class requires that BOTH the telnet and SSH services be enabled on the host machine and that port forwarding be enabled. For a SSH client that does not require port forwarding see the com.jscape.inet.ssh.Ssh class.

Upon establishing a connection the Telnet server may attempt to perform option negotiation (see RFC 855). Any optionnegotiation options exchanged must be handled prior to receiving a login or shell prompt.

To handle option negotiation you must add a TelnetListener to the Telnet instance and overload the doOption, dontOption, willOption and wontOption methods.

Once option negotiation has completed sucessfully a separate thread is spawned that reads data sent by the Telnet server. You can capture this data by overloading the dataReceived method in the TelnetListener interface or TelnetAdapter class.

See the Ssh class to interact with a remote shell without port forwarding thru the Telnet service. Use of this class requires that the Telnet service be enabled on the remote host.

Example Usage:

 public class TelnetExample extends TelnetAdapter {

      private TelnetSsh telnet = null;
      private OutputStream output = null;
      private static BufferedReader reader = null;
      private boolean connected = false;
      private String hostname = "10.0.0.1";
      private String sshHostname = "10.0.0.1";
      private String sshUsername = "jsmith";
      private String sshPassword = "secret";
      private SshParameters sshParams = null;

      public TelnetExample() throws IOException, TelnetException {

              // create SSH connection parameters
              sshParams = new SshParameters(sshHostname,sshUsername,sshPassword);

              // create new TelnetSsh instance
              telnet = new TelnetSsh(sshParams,hostname);

              // register this class as TelnetListener
              telnet.addTelnetListener(this);

              // establish Telnet connection
              telnet.connect();
              connected = true;

              // get output stream
              output = telnet.getOutputStream();

              // sends all data entered at console to Telnet server
              String input = null;
              while ((input = reader.readLine()) != null) {
                      if (connected) {
                              ((TelnetOutputStream) output).println(input);
             } else {
                              break;
             }
         }
     }

      // Invoked when Telnet socked is connected.
      public void connected(TelnetConnectedEvent event) {
              System.out.println("Connected");
     }

      // Invoked when Telnet socket is disconnected. Disconnect can
      public void disconnected(TelnetDisconnectedEvent event) {
              connected = false;
              System.out.print("Disconnected.  Press enter key to quit.");
     }

      // Invoked when Telnet server requests that the Telnet client begin performing specified TelnetOption.
      public void doOption(DoOptionEvent event) {
              // refuse any options requested by Telnet server
              telnet.sendWontOption(event.getOption());
     }

      // Invoked when Telnet server offers to begin performing specified TelnetOption.
      public void willOption(WillOptionEvent event) {
              // refuse any options offered by Telnet server
              telnet.sendDontOption(event.getOption());
     }

      // Invoked when data is received from Telnet server.
      public void dataReceived(TelnetDataReceivedEvent event) {
              // print data recevied from Telnet server to console
              System.out.print(event.getData());
     }

      // starts console program
      public static void main(String[] args) {
              try {
                      // create BufferedReader to read data from console
                      reader = new BufferedReader(new InputStreamReader(System.in));

                      // create new TelnetExample instance
                      TelnetExample example = new TelnetExample();

         } catch (Exception e) {
                      e.printStackTrace(System.out);
         }
     }

 }

 

See Also:

Ssh, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.jscape.inet.telnet.Telnet

Telnet.ByteDecoder, Telnet.DefaultDecoder, Telnet.EUCKoreanDecoder, Telnet.UTF8Decoder

Field Summary

Fields inherited from class com.jscape.inet.telnet.Telnet

COMMAND_MAP, TC_AO, TC_AYT, TC_BRK, TC_DM, TC_DO, TC_DONT, TC_GA, TC_IP, TC_NOP, TC_SB, TC_SE, TC_WILL, TC_WONT, TSC_BEL, TSC_BS, TSC_CR, TSC_EC, TSC_EL, TSC_FF, TSC_HT, TSC_IAC, TSC_LF, TSC_NULL, TSC_VT

Constructor Summary

Constructors

Constructor and Description
TelnetSsh(SshParameters sshParameters, java.lang.String hostname) Creates a new TelnetSsh instance.

Method Summary

Modifier and Type	Method and Description
void	connect() Establishes connection with SSH server and creates secure tunnel to Telnet server.
void	disconnect() Closes tunnel to Telnet server and closes connection with SSH server.
SshParameters	getSshParameters() Gets SSH parameters used in establishing connection with SSH server.
void	setSshParameters(SshParameters parameters) Sets SSH parameters used in establishing connection with SSH server.

Methods inherited from class com.jscape.inet.telnet.Telnet

addTelnetListener, clearProxySettings, getCharacterSet, getCommandName, getDebug, getDebugStream, getHostname, getInputStream, getOutputStream, getPort, getReader, getReadingTimeout, getTimeout, getWriter, removeTelnetListener, sendCommand, sendCommand, sendDontOption, sendDoOption, sendOptionSubnegotiation, sendWillOption, sendWontOption, setCharacterSet, setDebug, setDebugStream, setHostname, setPort, setProxyAuthentication, setProxyHost, setProxyType, setReadingTimeout, setTimeout

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TelnetSsh

public TelnetSsh(SshParameters sshParameters,
                 java.lang.String hostname)

Creates a new TelnetSsh instance.

Parameters:

hostname -

sshParameters -

Method Detail

connect

public void connect()
             throws TelnetException

Establishes connection with SSH server and creates secure tunnel to Telnet server.

Overrides:

connect in class Telnet

Throws:

TelnetException - if an I/O or Telnet related error occurs

disconnect

public void disconnect()

Closes tunnel to Telnet server and closes connection with SSH server.

Overrides:

disconnect in class Telnet

getSshParameters

public SshParameters getSshParameters()

Gets SSH parameters used in establishing connection with SSH server.

Returns:

the SSH parameters

See Also:

SshParameters

setSshParameters

public void setSshParameters(SshParameters parameters)

Sets SSH parameters used in establishing connection with SSH server.

Parameters:

parameters - the SSH parameters

See Also:

SshParameters