rfbproto.java

JAVA版vpn客户端,是在web上实现远程访问的最佳方式.

//
//  Copyright (C) 2001-2004 HorizonLive.com, Inc.  All Rights Reserved.
//  Copyright (C) 2001-2006 Constantin Kaplinsky.  All Rights Reserved.
//  Copyright (C) 2000 Tridia Corporation.  All Rights Reserved.
//  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
//
//  This is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This software is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this software; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
//  USA.
//

//
// RfbProto.java
//

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import java.net.Socket;
import java.util.zip.*;

class RfbProto {

  final static String
    versionMsg_3_3 = "RFB 003.003\n",
    versionMsg_3_7 = "RFB 003.007\n",
    versionMsg_3_8 = "RFB 003.008\n";

  // Vendor signatures: standard VNC/RealVNC, TridiaVNC, and TightVNC
  final static String
    StandardVendor  = "STDV",
    TridiaVncVendor = "TRDV",
    TightVncVendor  = "TGHT";

  // Security types
  final static int
    SecTypeInvalid = 0,
    SecTypeNone    = 1,
    SecTypeVncAuth = 2,
    SecTypeTight   = 16;

  // Supported tunneling types
  final static int
    NoTunneling = 0;
  final static String
    SigNoTunneling = "NOTUNNEL";

  // Supported authentication types
  final static int
    AuthNone      = 1,
    AuthVNC       = 2,
    AuthUnixLogin = 129;
  final static String
    SigAuthNone      = "NOAUTH__",
    SigAuthVNC       = "VNCAUTH_",
    SigAuthUnixLogin = "ULGNAUTH";

  // VNC authentication results
  final static int
    VncAuthOK      = 0,
    VncAuthFailed  = 1,
    VncAuthTooMany = 2;

  // Server-to-client messages
  final static int
    FramebufferUpdate   = 0,
    SetColourMapEntries = 1,
    Bell                = 2,
    ServerCutText       = 3;

  // Client-to-server messages
  final static int
    SetPixelFormat           = 0,
    FixColourMapEntries      = 1,
    SetEncodings             = 2,
    FramebufferUpdateRequest = 3,
    KeyboardEvent            = 4,
    PointerEvent             = 5,
    ClientCutText            = 6;

  // Supported encodings and pseudo-encodings
  final static int
    EncodingRaw            = 0,
    EncodingCopyRect       = 1,
    EncodingRRE            = 2,
    EncodingCoRRE          = 4,
    EncodingHextile        = 5,
    EncodingZlib           = 6,
    EncodingTight          = 7,
    EncodingZRLE           = 16,
    EncodingCompressLevel0 = 0xFFFFFF00,
    EncodingQualityLevel0  = 0xFFFFFFE0,
    EncodingXCursor        = 0xFFFFFF10,
    EncodingRichCursor     = 0xFFFFFF11,
    EncodingPointerPos     = 0xFFFFFF18,
    EncodingLastRect       = 0xFFFFFF20,
    EncodingNewFBSize      = 0xFFFFFF21;
  final static String
    SigEncodingRaw            = "RAW_____",
    SigEncodingCopyRect       = "COPYRECT",
    SigEncodingRRE            = "RRE_____",
    SigEncodingCoRRE          = "CORRE___",
    SigEncodingHextile        = "HEXTILE_",
    SigEncodingZlib           = "ZLIB____",
    SigEncodingTight          = "TIGHT___",
    SigEncodingZRLE           = "ZRLE____",
    SigEncodingCompressLevel0 = "COMPRLVL",
    SigEncodingQualityLevel0  = "JPEGQLVL",
    SigEncodingXCursor        = "X11CURSR",
    SigEncodingRichCursor     = "RCHCURSR",
    SigEncodingPointerPos     = "POINTPOS",
    SigEncodingLastRect       = "LASTRECT",
    SigEncodingNewFBSize      = "NEWFBSIZ";

  final static int MaxNormalEncoding = 255;

  // Contstants used in the Hextile decoder
  final static int
    HextileRaw                 = 1,
    HextileBackgroundSpecified = 2,
    HextileForegroundSpecified = 4,
    HextileAnySubrects         = 8,
    HextileSubrectsColoured    = 16;

  // Contstants used in the Tight decoder
  final static int TightMinToCompress = 12;
  final static int
    TightExplicitFilter = 0x04,
    TightFill           = 0x08,
    TightJpeg           = 0x09,
    TightMaxSubencoding = 0x09,
    TightFilterCopy     = 0x00,
    TightFilterPalette  = 0x01,
    TightFilterGradient = 0x02;


  String host;
  int port;
  Socket sock;
  DataInputStream is;
  OutputStream os;
  SessionRecorder rec;
  boolean inNormalProtocol = false;
  VncViewer viewer;

  // Java on UNIX does not call keyPressed() on some keys, for example
  // swedish keys To prevent our workaround to produce duplicate
  // keypresses on JVMs that actually works, keep track of if
  // keyPressed() for a "broken" key was called or not. 
  boolean brokenKeyPressed = false;

  // This will be set to true on the first framebuffer update
  // containing Zlib-, ZRLE- or Tight-encoded data.
  boolean wereZlibUpdates = false;

  // This will be set to false if the startSession() was called after
  // we have received at least one Zlib-, ZRLE- or Tight-encoded
  // framebuffer update.
  boolean recordFromBeginning = true;

  // This fields are needed to show warnings about inefficiently saved
  // sessions only once per each saved session file.
  boolean zlibWarningShown;
  boolean tightWarningShown;

  // Before starting to record each saved session, we set this field
  // to 0, and increment on each framebuffer update. We don't flush
  // the SessionRecorder data into the file before the second update. 
  // This allows us to write initial framebuffer update with zero
  // timestamp, to let the player show initial desktop before
  // playback.
  int numUpdatesInSession;

  // Measuring network throughput.
  boolean timing;
  long timeWaitedIn100us;
  long timedKbits;

  // Protocol version and TightVNC-specific protocol options.
  int serverMajor, serverMinor;
  int clientMajor, clientMinor;
  boolean protocolTightVNC;
  CapsContainer tunnelCaps, authCaps;
  CapsContainer serverMsgCaps, clientMsgCaps;
  CapsContainer encodingCaps;

  // If true, informs that the RFB socket was closed.
  private boolean closed;

  //
  // Constructor. Make TCP connection to RFB server.
  //

  RfbProto(String h, int p, VncViewer v) throws IOException {
    viewer = v;
    host = h;
    port = p;

    if (viewer.socketFactory == null) {
      sock = new Socket(host, port);
    } else {
      try {
	Class factoryClass = Class.forName(viewer.socketFactory);
	SocketFactory factory = (SocketFactory)factoryClass.newInstance();
	if (viewer.inAnApplet)
	  sock = factory.createSocket(host, port, viewer);
	else
	  sock = factory.createSocket(host, port, viewer.mainArgs);
      } catch(Exception e) {
	e.printStackTrace();
	throw new IOException(e.getMessage());
      }
    }
    is = new DataInputStream(new BufferedInputStream(sock.getInputStream(),
						     16384));
    os = sock.getOutputStream();

    timing = false;
    timeWaitedIn100us = 5;
    timedKbits = 0;
  }


  synchronized void close() {
    try {
      sock.close();
      closed = true;
      System.out.println("RFB socket closed");
      if (rec != null) {
	rec.close();
	rec = null;
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  synchronized boolean closed() {
    return closed;
  }

  //
  // Read server's protocol version message
  //

  void readVersionMsg() throws Exception {

    byte[] b = new byte[12];

    readFully(b);

    if ((b[0] != 'R') || (b[1] != 'F') || (b[2] != 'B') || (b[3] != ' ')
	|| (b[4] < '0') || (b[4] > '9') || (b[5] < '0') || (b[5] > '9')
	|| (b[6] < '0') || (b[6] > '9') || (b[7] != '.')
	|| (b[8] < '0') || (b[8] > '9') || (b[9] < '0') || (b[9] > '9')
	|| (b[10] < '0') || (b[10] > '9') || (b[11] != '\n'))
    {
      throw new Exception("Host " + host + " port " + port +
			  " is not an RFB server");
    }

    serverMajor = (b[4] - '0') * 100 + (b[5] - '0') * 10 + (b[6] - '0');
    serverMinor = (b[8] - '0') * 100 + (b[9] - '0') * 10 + (b[10] - '0');

    if (serverMajor < 3) {
      throw new Exception("RFB server does not support protocol version 3");
    }
  }


  //
  // Write our protocol version message
  //

  void writeVersionMsg() throws IOException {
    clientMajor = 3;
    if (serverMajor > 3 || serverMinor >= 8) {
      clientMinor = 8;
      os.write(versionMsg_3_8.getBytes());
    } else if (serverMinor >= 7) {
      clientMinor = 7;
      os.write(versionMsg_3_7.getBytes());
    } else {
      clientMinor = 3;
      os.write(versionMsg_3_3.getBytes());
    }
    protocolTightVNC = false;
  }


  //
  // Negotiate the authentication scheme.
  //

  int negotiateSecurity() throws Exception {
    return (clientMinor >= 7) ?
      selectSecurityType() : readSecurityType();
  }

  //
  // Read security type from the server (protocol version 3.3).
  //

  int readSecurityType() throws Exception {
    int secType = is.readInt();

    switch (secType) {
    case SecTypeInvalid:
      readConnFailedReason();
      return SecTypeInvalid;	// should never be executed
    case SecTypeNone:
    case SecTypeVncAuth:
      return secType;
    default:
      throw new Exception("Unknown security type from RFB server: " + secType);
    }
  }

  //
  // Select security type from the server's list (protocol versions 3.7/3.8).
  //

  int selectSecurityType() throws Exception {
    int secType = SecTypeInvalid;

    // Read the list of secutiry types.
    int nSecTypes = is.readUnsignedByte();
    if (nSecTypes == 0) {
      readConnFailedReason();
      return SecTypeInvalid;	// should never be executed
    }
    byte[] secTypes = new byte[nSecTypes];
    readFully(secTypes);

    // Find out if the server supports TightVNC protocol extensions
    for (int i = 0; i < nSecTypes; i++) {
      if (secTypes[i] == SecTypeTight) {
	protocolTightVNC = true;
	os.write(SecTypeTight);
	return SecTypeTight;
      }
    }

    // Find first supported security type.
    for (int i = 0; i < nSecTypes; i++) {
      if (secTypes[i] == SecTypeNone || secTypes[i] == SecTypeVncAuth) {
	secType = secTypes[i];
	break;
      }
    }

    if (secType == SecTypeInvalid) {
      throw new Exception("Server did not offer supported security type");
    } else {
      os.write(secType);
    }

    return secType;
  }

  //
  // Perform "no authentication".
  //

  void authenticateNone() throws Exception {
    if (clientMinor >= 8)
      readSecurityResult("No authentication");
  }

  //
  // Perform standard VNC Authentication.
  //

  void authenticateVNC(String pw) throws Exception {
    byte[] challenge = new byte[16];
    readFully(challenge);

    if (pw.length() > 8)
      pw = pw.substring(0, 8);	// Truncate to 8 chars

    // Truncate password on the first zero byte.
    int firstZero = pw.indexOf(0);
    if (firstZero != -1)
      pw = pw.substring(0, firstZero);

    byte[] key = {0, 0, 0, 0, 0, 0, 0, 0};
    System.arraycopy(pw.getBytes(), 0, key, 0, pw.length());

    DesCipher des = new DesCipher(key);

    des.encrypt(challenge, 0, challenge, 0);
    des.encrypt(challenge, 8, challenge, 8);

    os.write(challenge);

    readSecurityResult("VNC authentication");
  }

  //
  // Read security result.
  // Throws an exception on authentication failure.
  //

  void readSecurityResult(String authType) throws Exception {
    int securityResult = is.readInt();

    switch (securityResult) {
    case VncAuthOK:
      System.out.println(authType + ": success");
      break;
    case VncAuthFailed:
      if (clientMinor >= 8)
        readConnFailedReason();
      throw new Exception(authType + ": failed");
    case VncAuthTooMany:
      throw new Exception(authType + ": failed, too many tries");
    default:
      throw new Exception(authType + ": unknown result " + securityResult);
    }
  }

  //
  // Read the string describing the reason for a connection failure,
  // and throw an exception.
  //

  void readConnFailedReason() throws Exception {