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    /* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/*
Copyright (c) 2002-2018 ymnk, JCraft,Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright 
     notice, this list of conditions and the following disclaimer in 
     the documentation and/or other materials provided with the distribution.

  3. The names of the authors may not be used to endorse or promote products
     derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

package acscommons.com.jcraft.jsch;

import java.io.*;
import java.net.*;
import java.util.Vector;

public class Session implements Runnable{

  // http://ietf.org/internet-drafts/draft-ietf-secsh-assignednumbers-01.txt
  static final int SSH_MSG_DISCONNECT=                      1;
  static final int SSH_MSG_IGNORE=                          2;
  static final int SSH_MSG_UNIMPLEMENTED=                   3;
  static final int SSH_MSG_DEBUG=                           4;
  static final int SSH_MSG_SERVICE_REQUEST=                 5;
  static final int SSH_MSG_SERVICE_ACCEPT=                  6;
  static final int SSH_MSG_KEXINIT=                        20;
  static final int SSH_MSG_NEWKEYS=                        21;
  static final int SSH_MSG_KEXDH_INIT=                     30;
  static final int SSH_MSG_KEXDH_REPLY=                    31;
  static final int SSH_MSG_KEX_DH_GEX_GROUP=               31;
  static final int SSH_MSG_KEX_DH_GEX_INIT=                32;
  static final int SSH_MSG_KEX_DH_GEX_REPLY=               33;
  static final int SSH_MSG_KEX_DH_GEX_REQUEST=             34;
  static final int SSH_MSG_GLOBAL_REQUEST=                 80;
  static final int SSH_MSG_REQUEST_SUCCESS=                81;
  static final int SSH_MSG_REQUEST_FAILURE=                82;
  static final int SSH_MSG_CHANNEL_OPEN=                   90;
  static final int SSH_MSG_CHANNEL_OPEN_CONFIRMATION=      91;
  static final int SSH_MSG_CHANNEL_OPEN_FAILURE=           92;
  static final int SSH_MSG_CHANNEL_WINDOW_ADJUST=          93;
  static final int SSH_MSG_CHANNEL_DATA=                   94;
  static final int SSH_MSG_CHANNEL_EXTENDED_DATA=          95;
  static final int SSH_MSG_CHANNEL_EOF=                    96;
  static final int SSH_MSG_CHANNEL_CLOSE=                  97;
  static final int SSH_MSG_CHANNEL_REQUEST=                98;
  static final int SSH_MSG_CHANNEL_SUCCESS=                99;
  static final int SSH_MSG_CHANNEL_FAILURE=               100;

  private static final int PACKET_MAX_SIZE = 256 * 1024;

  private byte[] V_S;                                 // server version
  private byte[] V_C=Util.str2byte("SSH-2.0-JSCH-"+JSch.VERSION); // client version

  private byte[] I_C; // the payload of the client's SSH_MSG_KEXINIT
  private byte[] I_S; // the payload of the server's SSH_MSG_KEXINIT
  private byte[] K_S; // the host key

  private byte[] session_id;

  private byte[] IVc2s;
  private byte[] IVs2c;
  private byte[] Ec2s;
  private byte[] Es2c;
  private byte[] MACc2s;
  private byte[] MACs2c;

  private int seqi=0;
  private int seqo=0;

  String[] guess=null;
  private Cipher s2ccipher;
  private Cipher c2scipher;
  private MAC s2cmac;
  private MAC c2smac;
  //private byte[] mac_buf;
  private byte[] s2cmac_result1;
  private byte[] s2cmac_result2;

  private Compression deflater;
  private Compression inflater;

  private IO io;
  private Socket socket;
  private int timeout=0;

  private volatile boolean isConnected=false;

  private boolean isAuthed=false;

  private Thread connectThread=null;
  private Object lock=new Object();

  boolean x11_forwarding=false;
  boolean agent_forwarding=false;

  InputStream in=null;
  OutputStream out=null;

  static Random random;

  Buffer buf;
  Packet packet;

  SocketFactory socket_factory=null;

  static final int buffer_margin = 32 + // maximum padding length
                                   64 + // maximum mac length
                                   32;  // margin for deflater; deflater may inflate data

  private java.util.Hashtable config=null;

  private Proxy proxy=null;
  private UserInfo userinfo;

  private String hostKeyAlias=null;
  private int serverAliveInterval=0;
  private int serverAliveCountMax=1;

  private IdentityRepository identityRepository = null;
  private HostKeyRepository hostkeyRepository = null;

  protected boolean daemon_thread=false;

  private long kex_start_time=0L;

  int max_auth_tries = 6;
  int auth_failures = 0;

  String host="127.0.0.1";
  String org_host="127.0.0.1";
  int port=22;

  String username=null;
  byte[] password=null;

  JSch jsch;

  Session(JSch jsch, String username, String host, int port) throws JSchException{
    super();
    this.jsch=jsch;
    buf=new Buffer();
    packet=new Packet(buf);
    this.username = username;
    this.org_host = this.host = host;
    this.port = port;

    applyConfig();

    if(this.username==null) {
      try {
        this.username=(String)(System.getProperties().get("user.name"));
      }
      catch(SecurityException e){
        // ignore e
      }
    }

    if(this.username==null) {
      throw new JSchException("username is not given.");
    }
  }

  public void connect() throws JSchException{
    connect(timeout);
  }

  public void connect(int connectTimeout) throws JSchException{
    if(isConnected){
      throw new JSchException("session is already connected");
    }

    io=new IO();
    if(random==null){
      try{
	Class c=Class.forName(getConfig("random"));
        random=(Random)(c.newInstance());
      }
      catch(Exception e){ 
        throw new JSchException(e.toString(), e);
      }
    }
    Packet.setRandom(random);

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "Connecting to "+host+" port "+port);
    }

    try	{
      int i, j;

      if(proxy==null){
        InputStream in;
        OutputStream out;
	if(socket_factory==null){
          socket=Util.createSocket(host, port, connectTimeout);
	  in=socket.getInputStream();
	  out=socket.getOutputStream();
	}
	else{
          socket=socket_factory.createSocket(host, port);
	  in=socket_factory.getInputStream(socket);
	  out=socket_factory.getOutputStream(socket);
	}
	//if(timeout>0){ socket.setSoTimeout(timeout); }
        socket.setTcpNoDelay(true);
        io.setInputStream(in);
        io.setOutputStream(out);
      }
      else{
	synchronized(proxy){
          proxy.connect(socket_factory, host, port, connectTimeout);
	  io.setInputStream(proxy.getInputStream());
	  io.setOutputStream(proxy.getOutputStream());
          socket=proxy.getSocket();
	}
      }

      if(connectTimeout>0 && socket!=null){
        socket.setSoTimeout(connectTimeout);
      }

      isConnected=true;

      if(JSch.getLogger().isEnabled(Logger.INFO)){
        JSch.getLogger().log(Logger.INFO, 
                             "Connection established");
      }

      jsch.addSession(this);

      {
	// Some Cisco devices will miss to read '\n' if it is sent separately.
	byte[] foo=new byte[V_C.length+1];
	System.arraycopy(V_C, 0, foo, 0, V_C.length);
	foo[foo.length-1]=(byte)'\n';
	io.put(foo, 0, foo.length);
      }

      while(true){
        i=0;
        j=0;
        while(i0 && buf.buffer[i-1]==13){  // 0x0d
            i--;
          }
        }

        if(i<=3 || 
           ((i!=buf.buffer.length) &&
            (buf.buffer[0]!='S'||buf.buffer[1]!='S'||
             buf.buffer[2]!='H'||buf.buffer[3]!='-'))){
          // It must not start with 'SSH-'
          //System.err.println(new String(buf.buffer, 0, i);
          continue;
        }

        if(i==buf.buffer.length ||
           i<7 ||                                      // SSH-1.99 or SSH-2.0
           (buf.buffer[4]=='1' && buf.buffer[6]!='9')  // SSH-1.5
           ){
          throw new JSchException("invalid server's version string");
        }
        break;
      }

      V_S=new byte[i]; System.arraycopy(buf.buffer, 0, V_S, 0, i);
      //System.err.println("V_S: ("+i+") ["+new String(V_S)+"]");

      if(JSch.getLogger().isEnabled(Logger.INFO)){
        JSch.getLogger().log(Logger.INFO, 
                             "Remote version string: "+Util.byte2str(V_S));
        JSch.getLogger().log(Logger.INFO, 
                             "Local version string: "+Util.byte2str(V_C));
      }

      send_kexinit();

      buf=read(buf);
      if(buf.getCommand()!=SSH_MSG_KEXINIT){
        in_kex=false;
	throw new JSchException("invalid protocol: "+buf.getCommand());
      }

      if(JSch.getLogger().isEnabled(Logger.INFO)){
        JSch.getLogger().log(Logger.INFO, 
                             "SSH_MSG_KEXINIT received");
      }

      KeyExchange kex=receive_kexinit(buf);

      while(true){
	buf=read(buf);
	if(kex.getState()==buf.getCommand()){
          kex_start_time=System.currentTimeMillis();
          boolean result=kex.next(buf);
	  if(!result){
	    //System.err.println("verify: "+result);
            in_kex=false;
	    throw new JSchException("verify: "+result);
	  }
	}
	else{
          in_kex=false;
	  throw new JSchException("invalid protocol(kex): "+buf.getCommand());
	}
	if(kex.getState()==KeyExchange.STATE_END){
	  break;
	}
      }

      try{
        long tmp=System.currentTimeMillis();
        in_prompt = true;
        checkHost(host, port, kex);
        in_prompt = false;
        kex_start_time+=(System.currentTimeMillis()-tmp);
      }
      catch(JSchException ee){
        in_kex=false;
        in_prompt = false;
        throw ee;
      }

      send_newkeys();

      // receive SSH_MSG_NEWKEYS(21)
      buf=read(buf);
      //System.err.println("read: 21 ? "+buf.getCommand());
      if(buf.getCommand()==SSH_MSG_NEWKEYS){

        if(JSch.getLogger().isEnabled(Logger.INFO)){
          JSch.getLogger().log(Logger.INFO, 
                               "SSH_MSG_NEWKEYS received");
        }

	receive_newkeys(buf, kex);
      }
      else{
        in_kex=false;
	throw new JSchException("invalid protocol(newkyes): "+buf.getCommand());
      }

      try{
        String s = getConfig("MaxAuthTries");
        if(s!=null){
          max_auth_tries = Integer.parseInt(s);
        }
      }
      catch(NumberFormatException e){
        throw new JSchException("MaxAuthTries: "+getConfig("MaxAuthTries"), e);
      }

      boolean auth=false;
      boolean auth_cancel=false;

      UserAuth ua=null;
      try{
	Class c=Class.forName(getConfig("userauth.none"));
        ua=(UserAuth)(c.newInstance());
      }
      catch(Exception e){ 
        throw new JSchException(e.toString(), e);
      }

      auth=ua.start(this);

      String cmethods=getConfig("PreferredAuthentications");

      String[] cmethoda=Util.split(cmethods, ",");

      String smethods=null;
      if(!auth){
        smethods=((UserAuthNone)ua).getMethods();
        if(smethods!=null){
          smethods=smethods.toLowerCase();
        }
        else{
          // methods: publickey,password,keyboard-interactive
          //smethods="publickey,password,keyboard-interactive";
          smethods=cmethods;
        }
      }

      String[] smethoda=Util.split(smethods, ",");

      int methodi=0;

      loop:
      while(true){

	while(!auth && 
	      cmethoda!=null && methodi= max_auth_tries){
          if(JSch.getLogger().isEnabled(Logger.INFO)){
            JSch.getLogger().log(Logger.INFO, 
                                 "Login trials exceeds "+max_auth_tries);
          }
        }
        if(auth_cancel)
          throw new JSchException("Auth cancel");
        throw new JSchException("Auth fail");
      }

      if(socket!=null && (connectTimeout>0 || timeout>0)){
        socket.setSoTimeout(timeout);
      }

      isAuthed=true;

      synchronized(lock){
        if(isConnected){
          connectThread=new Thread(this);
          connectThread.setName("Connect thread "+host+" session");
          if(daemon_thread){
            connectThread.setDaemon(daemon_thread);
          }
          connectThread.start();

          requestPortForwarding();
        }
        else{
          // The session has been already down and
          // we don't have to start new thread.
        }
      }
    }
    catch(Exception e) {
      in_kex=false;
      try{
        if(isConnected){
          String message = e.toString();
          packet.reset();
          buf.checkFreeSize(1+4*3+message.length()+2+buffer_margin);
          buf.putByte((byte)SSH_MSG_DISCONNECT);
          buf.putInt(3);
          buf.putString(Util.str2byte(message));
          buf.putString(Util.str2byte("en"));
          write(packet);
        }
      }
      catch(Exception ee){}
      try{ disconnect(); } catch(Exception ee){ }
      isConnected=false;
      //e.printStackTrace();
      if(e instanceof RuntimeException) throw (RuntimeException)e;
      if(e instanceof JSchException) throw (JSchException)e;
      throw new JSchException("Session.connect: "+e);
    }
    finally{
      Util.bzero(this.password);
      this.password=null;
    }
  }

  private KeyExchange receive_kexinit(Buffer buf) throws Exception {
    int j=buf.getInt();
    if(j!=buf.getLength()){    // packet was compressed and
      buf.getByte();           // j is the size of deflated packet.
      I_S=new byte[buf.index-5];
    }
    else{
      I_S=new byte[j-1-buf.getByte()];
    }
   System.arraycopy(buf.buffer, buf.s, I_S, 0, I_S.length);

   if(!in_kex){     // We are in rekeying activated by the remote!
     send_kexinit();
   }

    guess=KeyExchange.guess(I_S, I_C);
    if(guess==null){
      throw new JSchException("Algorithm negotiation fail");
    }

    if(!isAuthed &&
       (guess[KeyExchange.PROPOSAL_ENC_ALGS_CTOS].equals("none") ||
        (guess[KeyExchange.PROPOSAL_ENC_ALGS_STOC].equals("none")))){
      throw new JSchException("NONE Cipher should not be chosen before authentification is successed.");
    }

    KeyExchange kex=null;
    try{
      Class c=Class.forName(getConfig(guess[KeyExchange.PROPOSAL_KEX_ALGS]));
      kex=(KeyExchange)(c.newInstance());
    }
    catch(Exception e){ 
      throw new JSchException(e.toString(), e);
    }

    kex.init(this, V_S, V_C, I_S, I_C);
    return kex;
  }

  private volatile boolean in_kex=false;
  private volatile boolean in_prompt=false;
  public void rekey() throws Exception {
    send_kexinit();
  }
  private void send_kexinit() throws Exception {
    if(in_kex)
      return;

    String cipherc2s=getConfig("cipher.c2s");
    String ciphers2c=getConfig("cipher.s2c");

    String[] not_available_ciphers=checkCiphers(getConfig("CheckCiphers"));
    if(not_available_ciphers!=null && not_available_ciphers.length>0){
      cipherc2s=Util.diffString(cipherc2s, not_available_ciphers);
      ciphers2c=Util.diffString(ciphers2c, not_available_ciphers);
      if(cipherc2s==null || ciphers2c==null){
        throw new JSchException("There are not any available ciphers.");
      }
    }

    String kex=getConfig("kex");
    String[] not_available_kexes=checkKexes(getConfig("CheckKexes"));
    if(not_available_kexes!=null && not_available_kexes.length>0){
      kex=Util.diffString(kex, not_available_kexes);
      if(kex==null){
        throw new JSchException("There are not any available kexes.");
      }
    }

    String server_host_key = getConfig("server_host_key");
    String[] not_available_shks =
      checkSignatures(getConfig("CheckSignatures"));
    if(not_available_shks!=null && not_available_shks.length>0){
      server_host_key=Util.diffString(server_host_key, not_available_shks);
      if(server_host_key==null){
        throw new JSchException("There are not any available sig algorithm.");
      }
    }

    in_kex=true;
    kex_start_time=System.currentTimeMillis();

    // byte      SSH_MSG_KEXINIT(20)
    // byte[16]  cookie (random bytes)
    // string    kex_algorithms
    // string    server_host_key_algorithms
    // string    encryption_algorithms_client_to_server
    // string    encryption_algorithms_server_to_client
    // string    mac_algorithms_client_to_server
    // string    mac_algorithms_server_to_client
    // string    compression_algorithms_client_to_server
    // string    compression_algorithms_server_to_client
    // string    languages_client_to_server
    // string    languages_server_to_client
    Buffer buf = new Buffer();                // send_kexinit may be invoked
    Packet packet = new Packet(buf);          // by user thread.
    packet.reset();
    buf.putByte((byte) SSH_MSG_KEXINIT);
    synchronized(random){
      random.fill(buf.buffer, buf.index, 16); buf.skip(16);
    }
    buf.putString(Util.str2byte(kex));
    buf.putString(Util.str2byte(server_host_key));
    buf.putString(Util.str2byte(cipherc2s));
    buf.putString(Util.str2byte(ciphers2c));
    buf.putString(Util.str2byte(getConfig("mac.c2s")));
    buf.putString(Util.str2byte(getConfig("mac.s2c")));
    buf.putString(Util.str2byte(getConfig("compression.c2s")));
    buf.putString(Util.str2byte(getConfig("compression.s2c")));
    buf.putString(Util.str2byte(getConfig("lang.c2s")));
    buf.putString(Util.str2byte(getConfig("lang.s2c")));
    buf.putByte((byte)0);
    buf.putInt(0);

    buf.setOffSet(5);
    I_C=new byte[buf.getLength()];
    buf.getByte(I_C);

    write(packet);

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "SSH_MSG_KEXINIT sent");
    }
  }

  private void send_newkeys() throws Exception {
    // send SSH_MSG_NEWKEYS(21)
    packet.reset();
    buf.putByte((byte)SSH_MSG_NEWKEYS);
    write(packet);

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "SSH_MSG_NEWKEYS sent");
    }
  }

  private void checkHost(String chost, int port, KeyExchange kex) throws JSchException {
    String shkc=getConfig("StrictHostKeyChecking");

    if(hostKeyAlias!=null){
      chost=hostKeyAlias;
    }

    //System.err.println("shkc: "+shkc);

    byte[] K_S=kex.getHostKey();
    String key_type=kex.getKeyType();
    String key_fprint=kex.getFingerPrint();

    if(hostKeyAlias==null && port!=22){
      chost=("["+chost+"]:"+port);
    }

    HostKeyRepository hkr=getHostKeyRepository();

    String hkh=getConfig("HashKnownHosts");
    if(hkh.equals("yes") && (hkr instanceof KnownHosts)){
      hostkey=((KnownHosts)hkr).createHashedHostKey(chost, K_S);
    }
    else{
      hostkey=new HostKey(chost, K_S);
    }

    int i=0;
    synchronized(hkr){
      i=hkr.check(chost, K_S);
    }

    boolean insert=false;
    if((shkc.equals("ask") || shkc.equals("yes")) &&
       i==HostKeyRepository.CHANGED){
      String file=null;
      synchronized(hkr){
	file=hkr.getKnownHostsRepositoryID();
      }
      if(file==null){file="known_hosts";}

      boolean b=false;

      if(userinfo!=null){
        String message=
"WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!\n"+
"IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!\n"+
"Someone could be eavesdropping on you right now (man-in-the-middle attack)!\n"+
"It is also possible that the "+key_type+" host key has just been changed.\n"+
"The fingerprint for the "+key_type+" key sent by the remote host "+chost+" is\n"+
key_fprint+".\n"+
"Please contact your system administrator.\n"+
"Add correct host key in "+file+" to get rid of this message.";

        if(shkc.equals("ask")){
          b=userinfo.promptYesNo(message+
                                 "\nDo you want to delete the old key and insert the new key?");
        }
        else{  // shkc.equals("yes")
          userinfo.showMessage(message);
        }
      }

      if(!b){
        throw new JSchException("HostKey has been changed: "+chost);
      }

      synchronized(hkr){
        hkr.remove(chost, 
                   kex.getKeyAlgorithName(),
                   null);
        insert=true;
      }
    }

    if((shkc.equals("ask") || shkc.equals("yes")) &&
       (i!=HostKeyRepository.OK) && !insert){
      if(shkc.equals("yes")){
	throw new JSchException("reject HostKey: "+host);
      }
      //System.err.println("finger-print: "+key_fprint);
      if(userinfo!=null){
	boolean foo=userinfo.promptYesNo(
"The authenticity of host '"+host+"' can't be established.\n"+
key_type+" key fingerprint is "+key_fprint+".\n"+
"Are you sure you want to continue connecting?"
					 );
	if(!foo){
	  throw new JSchException("reject HostKey: "+host);
	}
	insert=true;
      }
      else{
	if(i==HostKeyRepository.NOT_INCLUDED) 
	  throw new JSchException("UnknownHostKey: "+host+". "+key_type+" key fingerprint is "+key_fprint);
	else 
          throw new JSchException("HostKey has been changed: "+host);
      }
    }

    if(shkc.equals("no") && 
       HostKeyRepository.NOT_INCLUDED==i){
      insert=true;
    }

    if(i==HostKeyRepository.OK){
      HostKey[] keys =
        hkr.getHostKey(chost, kex.getKeyAlgorithName());
      String _key= Util.byte2str(Util.toBase64(K_S, 0, K_S.length));
      for(int j=0; j< keys.length; j++){
        if(keys[i].getKey().equals(_key) &&
           keys[j].getMarker().equals("@revoked")){
          if(userinfo!=null){
            userinfo.showMessage(
"The "+ key_type +" host key for "+ host +" is marked as revoked.\n"+
"This could mean that a stolen key is being used to "+
"impersonate this host.");
          }
          if(JSch.getLogger().isEnabled(Logger.INFO)){
            JSch.getLogger().log(Logger.INFO, 
                                 "Host '"+host+"' has provided revoked key.");
          }
          throw new JSchException("revoked HostKey: "+host);
        }
      }
    }

    if(i==HostKeyRepository.OK &&
       JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "Host '"+host+"' is known and matches the "+key_type+" host key");
    }

    if(insert &&
       JSch.getLogger().isEnabled(Logger.WARN)){
      JSch.getLogger().log(Logger.WARN, 
                           "Permanently added '"+host+"' ("+key_type+") to the list of known hosts.");
    }

    if(insert){
      synchronized(hkr){
	hkr.add(hostkey, userinfo);
      }
    }
  }

//public void start(){ (new Thread(this)).start();  }

  public Channel openChannel(String type) throws JSchException{
    if(!isConnected){
      throw new JSchException("session is down");
    }
    try{
      Channel channel=Channel.getChannel(type);
      addChannel(channel);
      channel.init();
      if(channel instanceof ChannelSession){
        applyConfigChannel((ChannelSession)channel);
      }
      return channel;
    }
    catch(Exception e){
      //e.printStackTrace();
    }
    return null;
  }

  // encode will bin invoked in write with synchronization.
  public void encode(Packet packet) throws Exception{
//System.err.println("encode: "+packet.buffer.getCommand());
//System.err.println("        "+packet.buffer.index);
//if(packet.buffer.getCommand()==96){
//Thread.dumpStack();
//}
    if(deflater!=null){
      compress_len[0]=packet.buffer.index;
      packet.buffer.buffer=deflater.compress(packet.buffer.buffer, 
                                             5, compress_len);
      packet.buffer.index=compress_len[0];
    }
    if(c2scipher!=null){
      //packet.padding(c2scipher.getIVSize());
      packet.padding(c2scipher_size);
      int pad=packet.buffer.buffer[4];
      synchronized(random){
	random.fill(packet.buffer.buffer, packet.buffer.index-pad, pad);
      }
    }
    else{
      packet.padding(8);
    }

    if(c2smac!=null){
      c2smac.update(seqo);
      c2smac.update(packet.buffer.buffer, 0, packet.buffer.index);
      c2smac.doFinal(packet.buffer.buffer, packet.buffer.index);
    }
    if(c2scipher!=null){
      byte[] buf=packet.buffer.buffer;
      c2scipher.update(buf, 0, packet.buffer.index, buf, 0);
    }
    if(c2smac!=null){
      packet.buffer.skip(c2smac.getBlockSize());
    }
  }

  int[] uncompress_len=new int[1];
  int[] compress_len=new int[1];

  private int s2ccipher_size=8;
  private int c2scipher_size=8;
  public Buffer read(Buffer buf) throws Exception{
    int j=0;
    while(true){
      buf.reset();
      io.getByte(buf.buffer, buf.index, s2ccipher_size); 
      buf.index+=s2ccipher_size;
      if(s2ccipher!=null){
        s2ccipher.update(buf.buffer, 0, s2ccipher_size, buf.buffer, 0);
      }
      j=((buf.buffer[0]<<24)&0xff000000)|
        ((buf.buffer[1]<<16)&0x00ff0000)|
        ((buf.buffer[2]<< 8)&0x0000ff00)|
        ((buf.buffer[3]    )&0x000000ff);
      // RFC 4253 6.1. Maximum Packet Length
      if(j<5 || j>PACKET_MAX_SIZE){
        start_discard(buf, s2ccipher, s2cmac, j, PACKET_MAX_SIZE);
      }
      int need = j+4-s2ccipher_size;
      //if(need<0){
      //  throw new IOException("invalid data");
      //}
      if((buf.index+need)>buf.buffer.length){
        byte[] foo=new byte[buf.index+need];
        System.arraycopy(buf.buffer, 0, foo, 0, buf.index);
        buf.buffer=foo;
      }

      if((need%s2ccipher_size)!=0){
        String message="Bad packet length "+need;
        if(JSch.getLogger().isEnabled(Logger.FATAL)){
          JSch.getLogger().log(Logger.FATAL, message); 
        }
        start_discard(buf, s2ccipher, s2cmac, j, PACKET_MAX_SIZE-s2ccipher_size);
      }

      if(need>0){
	io.getByte(buf.buffer, buf.index, need); buf.index+=(need);
	if(s2ccipher!=null){
	  s2ccipher.update(buf.buffer, s2ccipher_size, need, buf.buffer, s2ccipher_size);
	}
      }

      if(s2cmac!=null){
	s2cmac.update(seqi);
	s2cmac.update(buf.buffer, 0, buf.index);

        s2cmac.doFinal(s2cmac_result1, 0);
	io.getByte(s2cmac_result2, 0, s2cmac_result2.length);
        if(!java.util.Arrays.equals(s2cmac_result1, s2cmac_result2)){
          if(need > PACKET_MAX_SIZE){
            throw new IOException("MAC Error");
          }
          start_discard(buf, s2ccipher, s2cmac, j, PACKET_MAX_SIZE-need);
          continue;
	}
      }

      seqi++;

      if(inflater!=null){
        //inflater.uncompress(buf);
	int pad=buf.buffer[4];
	uncompress_len[0]=buf.index-5-pad;
	byte[] foo=inflater.uncompress(buf.buffer, 5, uncompress_len);
	if(foo!=null){
	  buf.buffer=foo;
	  buf.index=5+uncompress_len[0];
	}
	else{
	  System.err.println("fail in inflater");
	  break;
	}
      }

      int type=buf.getCommand()&0xff;
      //System.err.println("read: "+type);
      if(type==SSH_MSG_DISCONNECT){
        buf.rewind();
        buf.getInt();buf.getShort();
	int reason_code=buf.getInt();
	byte[] description=buf.getString();
	byte[] language_tag=buf.getString();
	throw new JSchException("SSH_MSG_DISCONNECT: "+
				    reason_code+
				" "+Util.byte2str(description)+
				" "+Util.byte2str(language_tag));
	//break;
      }
      else if(type==SSH_MSG_IGNORE){
      }
      else if(type==SSH_MSG_UNIMPLEMENTED){
        buf.rewind();
        buf.getInt();buf.getShort();
	int reason_id=buf.getInt();
        if(JSch.getLogger().isEnabled(Logger.INFO)){
          JSch.getLogger().log(Logger.INFO, 
                               "Received SSH_MSG_UNIMPLEMENTED for "+reason_id);
        }
      }
      else if(type==SSH_MSG_DEBUG){
        buf.rewind();
        buf.getInt();buf.getShort();
/*
	byte always_display=(byte)buf.getByte();
	byte[] message=buf.getString();
	byte[] language_tag=buf.getString();
	System.err.println("SSH_MSG_DEBUG:"+
			   " "+Util.byte2str(message)+
			   " "+Util.byte2str(language_tag));
*/
      }
      else if(type==SSH_MSG_CHANNEL_WINDOW_ADJUST){
          buf.rewind();
          buf.getInt();buf.getShort();
	  Channel c=Channel.getChannel(buf.getInt(), this);
	  if(c==null){
	  }
	  else{
	    c.addRemoteWindowSize(buf.getUInt()); 
	  }
      }
      else if(type==UserAuth.SSH_MSG_USERAUTH_SUCCESS){
        isAuthed=true;
        if(inflater==null && deflater==null){
          String method;
          method=guess[KeyExchange.PROPOSAL_COMP_ALGS_CTOS];
          initDeflater(method);
          method=guess[KeyExchange.PROPOSAL_COMP_ALGS_STOC];
          initInflater(method);
        }
        break;
      }
      else{
        break;
      }
    }
    buf.rewind();
    return buf;
  }

  private void start_discard(Buffer buf, Cipher cipher, MAC mac, 
                             int packet_length, int discard) throws JSchException, IOException{
    MAC discard_mac = null;

    if(!cipher.isCBC()){
      throw new JSchException("Packet corrupt");
    }

    if(packet_length!=PACKET_MAX_SIZE && mac != null){
      discard_mac = mac;
    }

    discard -= buf.index;

    while(discard>0){
      buf.reset();
      int len = discard>buf.buffer.length ? buf.buffer.length : discard;
      io.getByte(buf.buffer, 0, len);
      if(discard_mac!=null){
        discard_mac.update(buf.buffer, 0, len);
      }
      discard -= len;
    }

    if(discard_mac!=null){
      discard_mac.doFinal(buf.buffer, 0);
    }

    throw new JSchException("Packet corrupt");
  }

  byte[] getSessionId(){
    return session_id;
  }

  private void receive_newkeys(Buffer buf, KeyExchange kex) throws Exception {
    updateKeys(kex);
    in_kex=false;
  }
  private void updateKeys(KeyExchange kex) throws Exception{
    byte[] K=kex.getK();
    byte[] H=kex.getH();
    HASH hash=kex.getHash();

    if(session_id==null){
      session_id=new byte[H.length];
      System.arraycopy(H, 0, session_id, 0, H.length);
    }

    /*
      Initial IV client to server:     HASH (K || H || "A" || session_id)
      Initial IV server to client:     HASH (K || H || "B" || session_id)
      Encryption key client to server: HASH (K || H || "C" || session_id)
      Encryption key server to client: HASH (K || H || "D" || session_id)
      Integrity key client to server:  HASH (K || H || "E" || session_id)
      Integrity key server to client:  HASH (K || H || "F" || session_id)
    */

    buf.reset();
    buf.putMPInt(K);
    buf.putByte(H);
    buf.putByte((byte)0x41);
    buf.putByte(session_id);
    hash.update(buf.buffer, 0, buf.index);
    IVc2s=hash.digest();

    int j=buf.index-session_id.length-1;

    buf.buffer[j]++;
    hash.update(buf.buffer, 0, buf.index);
    IVs2c=hash.digest();

    buf.buffer[j]++;
    hash.update(buf.buffer, 0, buf.index);
    Ec2s=hash.digest();

    buf.buffer[j]++;
    hash.update(buf.buffer, 0, buf.index);
    Es2c=hash.digest();

    buf.buffer[j]++;
    hash.update(buf.buffer, 0, buf.index);
    MACc2s=hash.digest();

    buf.buffer[j]++;
    hash.update(buf.buffer, 0, buf.index);
    MACs2c=hash.digest();

    try{
      Class c;
      String method;
  
      method=guess[KeyExchange.PROPOSAL_ENC_ALGS_STOC];
      c=Class.forName(getConfig(method));
      s2ccipher=(Cipher)(c.newInstance());
      while(s2ccipher.getBlockSize()>Es2c.length){
        buf.reset();
        buf.putMPInt(K);
        buf.putByte(H);
        buf.putByte(Es2c);
        hash.update(buf.buffer, 0, buf.index);
        byte[] foo=hash.digest();
        byte[] bar=new byte[Es2c.length+foo.length];
	System.arraycopy(Es2c, 0, bar, 0, Es2c.length);
	System.arraycopy(foo, 0, bar, Es2c.length, foo.length);
	Es2c=bar;
      }
      s2ccipher.init(Cipher.DECRYPT_MODE, Es2c, IVs2c);
      s2ccipher_size=s2ccipher.getIVSize();

      method=guess[KeyExchange.PROPOSAL_MAC_ALGS_STOC];
      c=Class.forName(getConfig(method));
      s2cmac=(MAC)(c.newInstance());
      MACs2c = expandKey(buf, K, H, MACs2c, hash, s2cmac.getBlockSize());
      s2cmac.init(MACs2c);
      //mac_buf=new byte[s2cmac.getBlockSize()];
      s2cmac_result1=new byte[s2cmac.getBlockSize()];
      s2cmac_result2=new byte[s2cmac.getBlockSize()];

      method=guess[KeyExchange.PROPOSAL_ENC_ALGS_CTOS];
      c=Class.forName(getConfig(method));
      c2scipher=(Cipher)(c.newInstance());
      while(c2scipher.getBlockSize()>Ec2s.length){
        buf.reset();
        buf.putMPInt(K);
        buf.putByte(H);
        buf.putByte(Ec2s);
        hash.update(buf.buffer, 0, buf.index);
        byte[] foo=hash.digest();
        byte[] bar=new byte[Ec2s.length+foo.length];
	System.arraycopy(Ec2s, 0, bar, 0, Ec2s.length);
	System.arraycopy(foo, 0, bar, Ec2s.length, foo.length);
	Ec2s=bar;
      }
      c2scipher.init(Cipher.ENCRYPT_MODE, Ec2s, IVc2s);
      c2scipher_size=c2scipher.getIVSize();

      method=guess[KeyExchange.PROPOSAL_MAC_ALGS_CTOS];
      c=Class.forName(getConfig(method));
      c2smac=(MAC)(c.newInstance());
      MACc2s = expandKey(buf, K, H, MACc2s, hash, c2smac.getBlockSize());
      c2smac.init(MACc2s);

      method=guess[KeyExchange.PROPOSAL_COMP_ALGS_CTOS];
      initDeflater(method);

      method=guess[KeyExchange.PROPOSAL_COMP_ALGS_STOC];
      initInflater(method);
    }
    catch(Exception e){ 
      if(e instanceof JSchException)
        throw e;
      throw new JSchException(e.toString(), e);
      //System.err.println("updatekeys: "+e); 
    }
  }


  /*
   * RFC 4253  7.2. Output from Key Exchange
   * If the key length needed is longer than the output of the HASH, the
   * key is extended by computing HASH of the concatenation of K and H and
   * the entire key so far, and appending the resulting bytes (as many as
   * HASH generates) to the key.  This process is repeated until enough
   * key material is available; the key is taken from the beginning of
   * this value.  In other words:
   *   K1 = HASH(K || H || X || session_id)   (X is e.g., "A")
   *   K2 = HASH(K || H || K1)
   *   K3 = HASH(K || H || K1 || K2)
   *   ...
   *   key = K1 || K2 || K3 || ...
   */
  private byte[] expandKey(Buffer buf, byte[] K, byte[] H, byte[] key,
                           HASH hash, int required_length) throws Exception {
    byte[] result = key;
    int size = hash.getBlockSize();
    while(result.length < required_length){
      buf.reset();
      buf.putMPInt(K);
      buf.putByte(H);
      buf.putByte(result);
      hash.update(buf.buffer, 0, buf.index);
      byte[] tmp = new byte[result.length+size];
      System.arraycopy(result, 0, tmp, 0, result.length);
      System.arraycopy(hash.digest(), 0, tmp, result.length, size);
      Util.bzero(result);
      result = tmp;
    }
    return result;
  }

  /*public*/ /*synchronized*/ void write(Packet packet, Channel c, int length) throws Exception{
    long t = getTimeout();
    while(true){
      if(in_kex){
        if(t>0L && (System.currentTimeMillis()-kex_start_time)>t){
          throw new JSchException("timeout in waiting for rekeying process.");
        }
        try{Thread.sleep(10);}
        catch(java.lang.InterruptedException e){};
        continue;
      }
      synchronized(c){

        if(c.rwsize=length){
          c.rwsize-=length;
          break;
        }

      }
      if(c.close || !c.isConnected()){
	throw new IOException("channel is broken");
      }

      boolean sendit=false;
      int s=0;
      byte command=0;
      int recipient=-1;
      synchronized(c){
	if(c.rwsize>0){
	  long len=c.rwsize;
          if(len>length){
            len=length;
          }
          if(len!=length){
            s=packet.shift((int)len, 
                           (c2scipher!=null ? c2scipher_size : 8),
                           (c2smac!=null ? c2smac.getBlockSize() : 0));
          }
	  command=packet.buffer.getCommand();
	  recipient=c.getRecipient();
	  length-=len;
	  c.rwsize-=len;
	  sendit=true;
	}
      }
      if(sendit){
	_write(packet);
        if(length==0){
          return;
        }
	packet.unshift(command, recipient, s, length);
      }

      synchronized(c){
        if(in_kex){
          continue;
        }
        if(c.rwsize>=length){
          c.rwsize-=length;
          break;
        }

        //try{ 
        //System.out.println("1wait: "+c.rwsize);
        //  c.notifyme++;
        //  c.wait(100); 
        //}
        //catch(java.lang.InterruptedException e){
        //}
        //finally{
        //  c.notifyme--;
        //}
      }
    }
    _write(packet);
  }

  public void write(Packet packet) throws Exception{
    // System.err.println("in_kex="+in_kex+" "+(packet.buffer.getCommand()));
    long t = getTimeout();
    while(in_kex){
      if(t>0L &&
         (System.currentTimeMillis()-kex_start_time)>t &&
         !in_prompt
         ){
        throw new JSchException("timeout in waiting for rekeying process.");
      }
      byte command=packet.buffer.getCommand();
      //System.err.println("command: "+command);
      if(command==SSH_MSG_KEXINIT ||
         command==SSH_MSG_NEWKEYS ||
         command==SSH_MSG_KEXDH_INIT ||
         command==SSH_MSG_KEXDH_REPLY ||
         command==SSH_MSG_KEX_DH_GEX_GROUP ||
         command==SSH_MSG_KEX_DH_GEX_INIT ||
         command==SSH_MSG_KEX_DH_GEX_REPLY ||
         command==SSH_MSG_KEX_DH_GEX_REQUEST ||
         command==SSH_MSG_DISCONNECT){
        break;
      }
      try{Thread.sleep(10);}
      catch(java.lang.InterruptedException e){};
    }
    _write(packet);
  }

  private void _write(Packet packet) throws Exception{
    synchronized(lock){
      encode(packet);
      if(io!=null){
        io.put(packet);
        seqo++;
      }
    }
  }

  Runnable thread;
  public void run(){
    thread=this;

    byte[] foo;
    Buffer buf=new Buffer();
    Packet packet=new Packet(buf);
    int i=0;
    Channel channel;
    int[] start=new int[1];
    int[] length=new int[1];
    KeyExchange kex=null;

    int stimeout=0;
    try{
      while(isConnected &&
	    thread!=null){
        try{
          buf=read(buf);
          stimeout=0;
        }
        catch(InterruptedIOException/*SocketTimeoutException*/ ee){
          if(!in_kex && stimeoutlport is 0, the tcp port will be allocated.
   * @param lport local port for local port forwarding 
   * @param host host address for local port forwarding
   * @param rport remote port number for local port forwarding
   * @return an allocated local TCP port number
   * @see #setPortForwardingL(String bind_address, int lport, String host, int rport, ServerSocketFactory ssf, int connectTimeout)
   */
  public int setPortForwardingL(int lport, String host, int rport) throws JSchException{
    return setPortForwardingL("127.0.0.1", lport, host, rport);
  }

  /**
   * Registers the local port forwarding.  If bind_address is an empty string
   * or '*', the port should be available from all interfaces.
   * If bind_address is "localhost" or
   * null, the listening port will be bound for local use only.
   * If lport is 0, the tcp port will be allocated.
   * @param bind_address bind address for local port forwarding
   * @param lport local port for local port forwarding 
   * @param host host address for local port forwarding
   * @param rport remote port number for local port forwarding
   * @return an allocated local TCP port number
   * @see #setPortForwardingL(String bind_address, int lport, String host, int rport, ServerSocketFactory ssf, int connectTimeout)
   */
  public int setPortForwardingL(String bind_address, int lport, String host, int rport) throws JSchException{
    return setPortForwardingL(bind_address, lport, host, rport, null);
  }

  /**
   * Registers the local port forwarding.
   * If bind_address is an empty string or "*",
   * the port should be available from all interfaces.
   * If bind_address is "localhost" or
   * null, the listening port will be bound for local use only.
   * If lport is 0, the tcp port will be allocated.
   * @param bind_address bind address for local port forwarding
   * @param lport local port for local port forwarding 
   * @param host host address for local port forwarding
   * @param rport remote port number for local port forwarding
   * @param ssf socket factory
   * @return an allocated local TCP port number
   * @see #setPortForwardingL(String bind_address, int lport, String host, int rport, ServerSocketFactory ssf, int connectTimeout)
   */
  public int setPortForwardingL(String bind_address, int lport, String host, int rport, ServerSocketFactory ssf) throws JSchException{
    return setPortForwardingL(bind_address, lport, host, rport, ssf, 0);
  }

  /**
   * Registers the local port forwarding.
   * If bind_address is an empty string
   * or "*", the port should be available from all interfaces.
   * If bind_address is "localhost" or
   * null, the listening port will be bound for local use only.
   * If lport is 0, the tcp port will be allocated.
   * @param bind_address bind address for local port forwarding
   * @param lport local port for local port forwarding 
   * @param host host address for local port forwarding
   * @param rport remote port number for local port forwarding
   * @param ssf socket factory
   * @param connectTimeout timeout for establishing port connection
   * @return an allocated local TCP port number 
   */
  public int setPortForwardingL(String bind_address, int lport, String host, int rport, ServerSocketFactory ssf, int connectTimeout) throws JSchException{
    PortWatcher pw=PortWatcher.addPort(this, bind_address, lport, host, rport, ssf);
    pw.setConnectTimeout(connectTimeout);
    Thread tmp=new Thread(pw);
    tmp.setName("PortWatcher Thread for "+host);
    if(daemon_thread){
      tmp.setDaemon(daemon_thread);
    }
    tmp.start();
    return pw.lport;
  }

  /**
   * Cancels the local port forwarding assigned
   * at local TCP port lport on loopback interface.
   *
   * @param lport local TCP port
   */
  public void delPortForwardingL(int lport) throws JSchException{
    delPortForwardingL("127.0.0.1", lport);
  }

  /**
   * Cancels the local port forwarding assigned
   * at local TCP port lport on bind_address interface.
   *
   * @param bind_address bind_address of network interfaces
   * @param lport local TCP port
   */
  public void delPortForwardingL(String bind_address, int lport) throws JSchException{
    PortWatcher.delPort(this, bind_address, lport);
  }

  /**
   * Lists the registered local port forwarding.
   *
   * @return a list of "lport:host:hostport"
   */
  public String[] getPortForwardingL() throws JSchException{
    return PortWatcher.getPortForwarding(this);
  }

  /**
   * Registers the remote port forwarding for the loopback interface
   * of the remote.
   *
   * @param rport remote port
   * @param host host address
   * @param lport local port
   * @see #setPortForwardingR(String bind_address, int rport, String host, int lport, SocketFactory sf)
   */
  public void setPortForwardingR(int rport, String host, int lport) throws JSchException{
    setPortForwardingR(null, rport, host, lport, (SocketFactory)null);
  }

  /**
   * Registers the remote port forwarding.
   * If bind_address is an empty string or "*",
   * the port should be available from all interfaces.
   * If bind_address is "localhost" or is not given,
   * the listening port will be bound for local use only.
   * Note that if GatewayPorts is "no" on the
   * remote, "localhost" is always used as a bind_address.
   *
   * @param bind_address bind address
   * @param rport remote port
   * @param host host address
   * @param lport local port
   * @see #setPortForwardingR(String bind_address, int rport, String host, int lport, SocketFactory sf)
   */
  public void setPortForwardingR(String bind_address, int rport, String host, int lport) throws JSchException{
    setPortForwardingR(bind_address, rport, host, lport, (SocketFactory)null);
  }

  /**
   * Registers the remote port forwarding for the loopback interface
   * of the remote.
   *
   * @param rport remote port
   * @param host host address
   * @param lport local port
   * @param sf socket factory
   * @see #setPortForwardingR(String bind_address, int rport, String host, int lport, SocketFactory sf)
   */
  public void setPortForwardingR(int rport, String host, int lport, SocketFactory sf) throws JSchException{
    setPortForwardingR(null, rport, host, lport, sf);
  }

  // TODO: This method should return the integer value as the assigned port.
  /**
   * Registers the remote port forwarding.
   * If bind_address is an empty string or "*",
   * the port should be available from all interfaces.
   * If bind_address is "localhost" or is not given,
   * the listening port will be bound for local use only.
   * Note that if GatewayPorts is "no" on the
   * remote, "localhost" is always used as a bind_address.
   * If rport is 0, the TCP port will be allocated on the remote.
   *
   * @param bind_address bind address
   * @param rport remote port
   * @param host host address
   * @param lport local port
   * @param sf socket factory
   */
  public void setPortForwardingR(String bind_address, int rport, String host, int lport, SocketFactory sf) throws JSchException{
    int allocated=_setPortForwardingR(bind_address, rport);
    ChannelForwardedTCPIP.addPort(this, bind_address,
                                  rport, allocated, host, lport, sf);
  }

  /**
   * Registers the remote port forwarding for the loopback interface
   * of the remote.
   * The TCP connection to rport on the remote will be
   * forwarded to an instance of the class daemon.
   * The class specified by daemon must implement
   * ForwardedTCPIPDaemon.
   *
   * @param rport remote port
   * @param daemon class name, which implements "ForwardedTCPIPDaemon"
   * @see #setPortForwardingR(String bind_address, int rport, String daemon, Object[] arg)
   */
  public void setPortForwardingR(int rport, String daemon) throws JSchException{
    setPortForwardingR(null, rport, daemon, null);
  }

  /**
   * Registers the remote port forwarding for the loopback interface
   * of the remote.
   * The TCP connection to rport on the remote will be
   * forwarded to an instance of the class daemon with
   * the argument arg.
   * The class specified by daemon must implement ForwardedTCPIPDaemon.
   *
   * @param rport remote port
   * @param daemon class name, which implements "ForwardedTCPIPDaemon"
   * @param arg arguments for "daemon"
   * @see #setPortForwardingR(String bind_address, int rport, String daemon, Object[] arg)
   */
  public void setPortForwardingR(int rport, String daemon, Object[] arg) throws JSchException{
    setPortForwardingR(null, rport, daemon, arg);
  }

  /**
   * Registers the remote port forwarding.
   * If bind_address is an empty string
   * or "*", the port should be available from all interfaces.
   * If bind_address is "localhost" or is not given,
   * the listening port will be bound for local use only.
   * Note that if GatewayPorts is "no" on the
   * remote, "localhost" is always used as a bind_address.
   * The TCP connection to rport on the remote will be
   * forwarded to an instance of the class daemon with the
   * argument arg. 
   * The class specified by daemon must implement ForwardedTCPIPDaemon.
   *
   * @param bind_address bind address
   * @param rport remote port
   * @param daemon class name, which implements "ForwardedTCPIPDaemon"
   * @param arg arguments for "daemon"
   * @see #setPortForwardingR(String bind_address, int rport, String daemon, Object[] arg)
   */
  public void setPortForwardingR(String bind_address, int rport, String daemon, Object[] arg) throws JSchException{
    int allocated = _setPortForwardingR(bind_address, rport);
    ChannelForwardedTCPIP.addPort(this, bind_address,
                                  rport, allocated, daemon, arg);
  }

  /**
   * Lists the registered remote port forwarding.
   *
   * @return a list of "rport:host:hostport"
   */
  public String[] getPortForwardingR() throws JSchException{
    return ChannelForwardedTCPIP.getPortForwarding(this);
  }

  private class Forwarding {
    String bind_address = null;
    int port = -1;
    String host = null;
    int hostport = -1;
  }

  /**
   * The given argument may be "[bind_address:]port:host:hostport" or
   * "[bind_address:]port host:hostport", which is from LocalForward command of
   * ~/.ssh/config .
   */
  private Forwarding parseForwarding(String conf) throws JSchException {
    String[] tmp = conf.split(" ");
    if(tmp.length>1){   // "[bind_address:]port host:hostport"
      Vector foo = new Vector();
      for(int i=0; ibind_address is an empty string or "*",
   * the port should be available from all interfaces.
   * If bind_address is "localhost" or is not given,
   * the listening port will be bound for local use only.
   *
   * @param conf configuration of local port forwarding
   * @return an assigned port number
   * @see #setPortForwardingL(String bind_address, int lport, String host, int rport)
   */
  public int setPortForwardingL(String conf) throws JSchException {
    Forwarding f = parseForwarding(conf);
    return setPortForwardingL(f.bind_address, f.port, f.host, f.hostport);
  }

  /**
   * Registers the remote port forwarding.  The argument should be
   * in the format like "[bind_address:]port:host:hostport".  If the 
   * bind_address is not given, the default is to only bind to loopback
   * addresses.  If the bind_address is "*" or an empty string,
   * then the forwarding is requested to listen on all interfaces.
   * Note that if GatewayPorts is "no" on the remote,
   * "localhost" is always used for bind_address.
   * If the specified remote is "0",
   * the TCP port will be allocated on the remote.
   *
   * @param conf configuration of remote port forwarding
   * @return an allocated TCP port on the remote.
   * @see #setPortForwardingR(String bind_address, int rport, String host, int rport)
   */
  public int setPortForwardingR(String conf) throws JSchException {
    Forwarding f = parseForwarding(conf);
    int allocated = _setPortForwardingR(f.bind_address, f.port);
    ChannelForwardedTCPIP.addPort(this, f.bind_address,
                                  f.port, allocated, f.host, f.hostport, null);
    return allocated;
  }

  /**
   * Instantiates an instance of stream-forwarder to host:port.
   * Set I/O stream to the given channel, and then invoke Channel#connect() method.
   *
   * @param host remote host, which the given stream will be plugged to.
   * @param port remote port, which the given stream will be plugged to.
   */
  public Channel getStreamForwarder(String host, int port) throws JSchException {
    ChannelDirectTCPIP channel = new ChannelDirectTCPIP();
    channel.init();
    this.addChannel(channel);
    channel.setHost(host);
    channel.setPort(port);
    return channel;
  } 

  private class GlobalRequestReply{
    private Thread thread=null;
    private int reply=-1;
    private int port=0;
    void setThread(Thread thread){
      this.thread=thread;
      this.reply=-1;
    }
    Thread getThread(){ return thread; }
    void setReply(int reply){ this.reply=reply; }
    int getReply(){ return this.reply; }
    int getPort(){ return this.port; }
    void setPort(int port){ this.port=port; }
  }
  private GlobalRequestReply grr=new GlobalRequestReply();
  private int _setPortForwardingR(String bind_address, int rport) throws JSchException{
    synchronized(grr){
    Buffer buf=new Buffer(100); // ??
    Packet packet=new Packet(buf);

    String address_to_bind=ChannelForwardedTCPIP.normalize(bind_address);

    grr.setThread(Thread.currentThread());
    grr.setPort(rport);

    try{
      // byte SSH_MSG_GLOBAL_REQUEST 80
      // string "tcpip-forward"
      // boolean want_reply
      // string  address_to_bind
      // uint32  port number to bind
      packet.reset();
      buf.putByte((byte) SSH_MSG_GLOBAL_REQUEST);
      buf.putString(Util.str2byte("tcpip-forward"));
      buf.putByte((byte)1);
      buf.putString(Util.str2byte(address_to_bind));
      buf.putInt(rport);
      write(packet);
    }
    catch(Exception e){
      grr.setThread(null);
      if(e instanceof Throwable)
        throw new JSchException(e.toString(), (Throwable)e);
      throw new JSchException(e.toString());
    }

    int count = 0;
    int reply = grr.getReply();
    while(count < 10 && reply == -1){
      try{ Thread.sleep(1000); }
      catch(Exception e){
      }
      count++; 
      reply = grr.getReply();
    }
    grr.setThread(null);
    if(reply != 1){
      throw new JSchException("remote port forwarding failed for listen port "+rport);
    }
    rport=grr.getPort();
    }
    return rport;
  }

  /**
   * Cancels the remote port forwarding assigned at remote TCP port rport.
   *
   * @param rport remote TCP port
   */
  public void delPortForwardingR(int rport) throws JSchException{
    this.delPortForwardingR(null, rport);
  }

  /**
   * Cancels the remote port forwarding assigned at
   * remote TCP port rport bound on the interface at
   * bind_address.
   *
   * @param bind_address bind address of the interface on the remote
   * @param rport remote TCP port
   */
  public void delPortForwardingR(String bind_address, int rport) throws JSchException{
    ChannelForwardedTCPIP.delPort(this, bind_address, rport);
  }

  private void initDeflater(String method) throws JSchException{
    if(method.equals("none")){
      deflater=null;
      return;
    }
    String foo=getConfig(method);
    if(foo!=null){
      if(method.equals("zlib") ||
         (isAuthed && method.equals("[email protected]"))){
        try{
          Class c=Class.forName(foo);
          deflater=(Compression)(c.newInstance());
          int level=6;
          try{ level=Integer.parseInt(getConfig("compression_level"));}
          catch(Exception ee){ }
          deflater.init(Compression.DEFLATER, level);
        }
        catch(NoClassDefFoundError ee){
          throw new JSchException(ee.toString(), ee);
        }
        catch(Exception ee){
          throw new JSchException(ee.toString(), ee);
          //System.err.println(foo+" isn't accessible.");
        }
      }
    }
  }
  private void initInflater(String method) throws JSchException{
    if(method.equals("none")){
      inflater=null;
      return;
    }
    String foo=getConfig(method);
    if(foo!=null){
      if(method.equals("zlib") ||
         (isAuthed && method.equals("[email protected]"))){
        try{
          Class c=Class.forName(foo);
          inflater=(Compression)(c.newInstance());
          inflater.init(Compression.INFLATER, 0);
        }
        catch(Exception ee){
          throw new JSchException(ee.toString(), ee);
	    //System.err.println(foo+" isn't accessible.");
        }
      }
    }
  }

  void addChannel(Channel channel){
    channel.setSession(this);
  }

  public void setProxy(Proxy proxy){ this.proxy=proxy; }
  public void setHost(String host){ this.host=host; }
  public void setPort(int port){ this.port=port; }
  void setUserName(String username){ this.username=username; }
  public void setUserInfo(UserInfo userinfo){ this.userinfo=userinfo; }
  public UserInfo getUserInfo(){ return userinfo; }
  public void setInputStream(InputStream in){ this.in=in; }
  public void setOutputStream(OutputStream out){ this.out=out; }
  public void setX11Host(String host){ ChannelX11.setHost(host); }
  public void setX11Port(int port){ ChannelX11.setPort(port); }
  public void setX11Cookie(String cookie){ ChannelX11.setCookie(cookie); }
  public void setPassword(String password){
    if(password!=null)
      this.password=Util.str2byte(password);
  }
  public void setPassword(byte[] password){ 
    if(password!=null){
      this.password=new byte[password.length];
      System.arraycopy(password, 0, this.password, 0, password.length);
    }
  }

  public void setConfig(java.util.Properties newconf){
    setConfig((java.util.Hashtable)newconf);
  }
 
  public void setConfig(java.util.Hashtable newconf){
    synchronized(lock){
      if(config==null) 
        config=new java.util.Hashtable();
      for(java.util.Enumeration e=newconf.keys() ; e.hasMoreElements() ;) {
        String key=(String)(e.nextElement());
        config.put(key, (String)(newconf.get(key)));
      }
    }
  }

  public void setConfig(String key, String value){
    synchronized(lock){ 
      if(config==null){
        config=new java.util.Hashtable();
      }
      config.put(key, value);
    }
  }

  public String getConfig(String key){
    Object foo=null;
    if(config!=null){
      foo=config.get(key);
      if(foo instanceof String) return (String)foo;
    }
    foo=jsch.getConfig(key);
    if(foo instanceof String) return (String)foo;
    return null;
  }

  public void setSocketFactory(SocketFactory sfactory){ 
    socket_factory=sfactory;
  }
  public boolean isConnected(){ return isConnected; }
  public int getTimeout(){ return timeout; }
  public void setTimeout(int timeout) throws JSchException {
    if(socket==null){
      if(timeout<0){
        throw new JSchException("invalid timeout value");
      }
      this.timeout=timeout;
      return;
    }
    try{
      socket.setSoTimeout(timeout);
      this.timeout=timeout;
    }
    catch(Exception e){
      if(e instanceof Throwable)
        throw new JSchException(e.toString(), (Throwable)e);
      throw new JSchException(e.toString());
    }
  }
  public String getServerVersion(){
    return Util.byte2str(V_S);
  }
  public String getClientVersion(){
    return Util.byte2str(V_C);
  }
  public void setClientVersion(String cv){
    V_C=Util.str2byte(cv);
  }

  public void sendIgnore() throws Exception{
    Buffer buf=new Buffer();
    Packet packet=new Packet(buf);
    packet.reset();
    buf.putByte((byte)SSH_MSG_IGNORE);
    write(packet);
  }

  private static final byte[] keepalivemsg=Util.str2byte("[email protected]");
  public void sendKeepAliveMsg() throws Exception{
    Buffer buf=new Buffer();
    Packet packet=new Packet(buf);
    packet.reset();
    buf.putByte((byte)SSH_MSG_GLOBAL_REQUEST);
    buf.putString(keepalivemsg);
    buf.putByte((byte)1);
    write(packet);
  }

  private static final byte[] nomoresessions=Util.str2byte("[email protected]");
  public void noMoreSessionChannels() throws Exception{
    Buffer buf=new Buffer();
    Packet packet=new Packet(buf);
    packet.reset();
    buf.putByte((byte)SSH_MSG_GLOBAL_REQUEST);
    buf.putString(nomoresessions);
    buf.putByte((byte)0);
    write(packet);
  }
  
  private HostKey hostkey=null;
  public HostKey getHostKey(){ return hostkey; }
  public String getHost(){return host;}
  public String getUserName(){return username;}
  public int getPort(){return port;}
  public void setHostKeyAlias(String hostKeyAlias){
    this.hostKeyAlias=hostKeyAlias;
  }
  public String getHostKeyAlias(){
    return hostKeyAlias;
  }

  /**
   * Sets the interval to send a keep-alive message.  If zero is
   * specified, any keep-alive message must not be sent.  The default interval
   * is zero.
   *
   * @param interval the specified interval, in milliseconds.
   * @see #getServerAliveInterval()
   */
  public void setServerAliveInterval(int interval) throws JSchException {
    setTimeout(interval);
    this.serverAliveInterval=interval;
  }

  /**
   * Returns setting for the interval to send a keep-alive message.
   *
   * @see #setServerAliveInterval(int)
   */
  public int getServerAliveInterval(){
    return this.serverAliveInterval;
  }

  /**
   * Sets the number of keep-alive messages which may be sent without
   * receiving any messages back from the server.  If this threshold is
   * reached while keep-alive messages are being sent, the connection will
   * be disconnected.  The default value is one.
   *
   * @param count the specified count
   * @see #getServerAliveCountMax()
   */
  public void setServerAliveCountMax(int count){
    this.serverAliveCountMax=count;
  }

  /**
   * Returns setting for the threshold to send keep-alive messages.
   *
   * @see #setServerAliveCountMax(int)
   */
  public int getServerAliveCountMax(){
    return this.serverAliveCountMax;
  }

  public void setDaemonThread(boolean enable){
    this.daemon_thread=enable;
  }

  private String[] checkCiphers(String ciphers){
    if(ciphers==null || ciphers.length()==0)
      return null;

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      JSch.getLogger().log(Logger.INFO, 
                           "CheckCiphers: "+ciphers);
    }

    String cipherc2s=getConfig("cipher.c2s");
    String ciphers2c=getConfig("cipher.s2c");

    Vector result=new Vector();
    String[] _ciphers=Util.split(ciphers, ",");
    for(int i=0; i<_ciphers.length; i++){
      String cipher=_ciphers[i];
      if(ciphers2c.indexOf(cipher) == -1 && cipherc2s.indexOf(cipher) == -1)
        continue;
      if(!checkCipher(getConfig(cipher))){
        result.addElement(cipher);
      }
    }
    if(result.size()==0)
      return null;
    String[] foo=new String[result.size()];
    System.arraycopy(result.toArray(), 0, foo, 0, result.size());

    if(JSch.getLogger().isEnabled(Logger.INFO)){
      for(int i=0; inull.
   *
   * @param identityRepository 
   * @see #getIdentityRepository()
   */
  public void setIdentityRepository(IdentityRepository identityRepository){
    this.identityRepository = identityRepository;
  }

  /**
   * Gets the identityRepository.
   * If this.identityRepository is null,
   * JSch#getIdentityRepository() will be invoked.
   *
   * @see JSch#getIdentityRepository()
   */
  IdentityRepository getIdentityRepository(){
    if(identityRepository == null)
      return jsch.getIdentityRepository();
    return identityRepository;
  }

  /**
   * Sets the hostkeyRepository, which will be referred in checking host keys. 
   *
   * @param hostkeyRepository 
   * @see #getHostKeyRepository()
   */
  public void setHostKeyRepository(HostKeyRepository hostkeyRepository){
    this.hostkeyRepository = hostkeyRepository;
  }

  /**
   * Gets the hostkeyRepository.
   * If this.hostkeyRepository is null,
   * JSch#getHostKeyRepository() will be invoked.
   *
   * @see JSch#getHostKeyRepository()
   */
  public HostKeyRepository getHostKeyRepository(){
    if(hostkeyRepository == null)
      return jsch.getHostKeyRepository();
    return hostkeyRepository;
  }

  /*
  // setProxyCommand("ssh -l user2 host2 -o 'ProxyCommand ssh user1@host1 nc host2 22' nc %h %p") 
  public void setProxyCommand(String command){
    setProxy(new ProxyCommand(command));
  }

  class ProxyCommand implements Proxy {
    String command;
    Process p = null;
    InputStream in = null;
    OutputStream out = null;
    ProxyCommand(String command){
      this.command = command;
    }
    public void connect(SocketFactory socket_factory, String host, int port, int timeout) throws Exception {
      String _command = command.replace("%h", host);
      _command = _command.replace("%p", new Integer(port).toString());
      p = Runtime.getRuntime().exec(_command);
      in = p.getInputStream();
      out = p.getOutputStream();
    }
    public Socket getSocket() { return null; }
    public InputStream getInputStream() { return in; }
    public OutputStream getOutputStream() { return out; }
    public void close() {
      try{
        if(p!=null){
          p.getErrorStream().close();
          p.getOutputStream().close();
          p.getInputStream().close();
          p.destroy();
          p=null;
        }
      }
      catch(IOException e){
      }
    }
  }
  */

  private void applyConfig() throws JSchException {
    ConfigRepository configRepository = jsch.getConfigRepository();
    if(configRepository == null){
      return;
    }

    ConfigRepository.Config config =
      configRepository.getConfig(org_host);

    String value = null;

    if(username==null){
      value = config.getUser();
      if(value != null)
        username = value;
    }

    value = config.getHostname();
    if(value != null)
      host = value;

    int port = config.getPort();
    if(port != -1)
      this.port = port;

    checkConfig(config, "kex");
    checkConfig(config, "server_host_key");

    checkConfig(config, "cipher.c2s");
    checkConfig(config, "cipher.s2c");
    checkConfig(config, "mac.c2s");
    checkConfig(config, "mac.s2c");
    checkConfig(config, "compression.c2s");
    checkConfig(config, "compression.s2c");
    checkConfig(config, "compression_level");

    checkConfig(config, "StrictHostKeyChecking");
    checkConfig(config, "HashKnownHosts");
    checkConfig(config, "PreferredAuthentications");
    checkConfig(config, "MaxAuthTries");
    checkConfig(config, "ClearAllForwardings");

    value = config.getValue("HostKeyAlias");
    if(value != null)
      this.setHostKeyAlias(value);

    value = config.getValue("UserKnownHostsFile");
    if(value != null) {
      KnownHosts kh = new KnownHosts(jsch);
      kh.setKnownHosts(value);
      this.setHostKeyRepository(kh);
    }

    String[] values = config.getValues("IdentityFile");
    if(values != null) {
      String[] global =
        configRepository.getConfig("").getValues("IdentityFile");
      if(global != null){
        for(int i = 0; i < global.length; i++){
          jsch.addIdentity(global[i]);
        }
      }
      else {
        global = new String[0];
      }
      if(values.length - global.length > 0){
        IdentityRepository.Wrapper ir =
          new IdentityRepository.Wrapper(jsch.getIdentityRepository(), true);
        for(int i = 0; i < values.length; i++){
          String ifile = values[i];
          for(int j = 0; j < global.length; j++){
            if(!ifile.equals(global[j]))
              continue;
            ifile = null;
            break;
          }
          if(ifile == null)
            continue;
          Identity identity =
            IdentityFile.newInstance(ifile, null, jsch);
          ir.add(identity);
        }
        this.setIdentityRepository(ir);
      }
    }

    value = config.getValue("ServerAliveInterval");
    if(value != null) {
      try {
        this.setServerAliveInterval(Integer.parseInt(value));
      }
      catch(NumberFormatException e){
      }
    }

    value = config.getValue("ConnectTimeout");
    if(value != null) {
      try {
        setTimeout(Integer.parseInt(value));
      }
      catch(NumberFormatException e){
      }
    }

    value = config.getValue("MaxAuthTries");
    if(value != null) {
      setConfig("MaxAuthTries", value);
    }

    value = config.getValue("ClearAllForwardings");
    if(value != null) {
      setConfig("ClearAllForwardings", value);
    }

  }

  private void applyConfigChannel(ChannelSession channel) throws JSchException {
    ConfigRepository configRepository = jsch.getConfigRepository();
    if(configRepository == null){
      return;
    }

    ConfigRepository.Config config =
      configRepository.getConfig(org_host);

    String value = null;

    value = config.getValue("ForwardAgent");
    if(value != null){
      channel.setAgentForwarding(value.equals("yes"));
    }

    value = config.getValue("RequestTTY");
    if(value != null){
      channel.setPty(value.equals("yes"));
    }
  }

  private void requestPortForwarding() throws JSchException {

    if(getConfig("ClearAllForwardings").equals("yes"))
      return;

    ConfigRepository configRepository = jsch.getConfigRepository();
    if(configRepository == null){
      return;
    }

    ConfigRepository.Config config =
      configRepository.getConfig(org_host);

    String[] values = config.getValues("LocalForward");
    if(values != null){
      for(int i = 0; i < values.length; i++) {
        setPortForwardingL(values[i]);
      }
    }

    values = config.getValues("RemoteForward");
    if(values != null){
      for(int i = 0; i < values.length; i++) {
        setPortForwardingR(values[i]);
      }
    }
  }

  private void checkConfig(ConfigRepository.Config config, String key){
    String value = config.getValue(key);
    if(value != null)
      this.setConfig(key, value);
  }
}




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