Source Code Cross Referenced for TransportManager.java in  » Net » Ganymed-SSH-2 » ch » ethz » ssh2 » transport » Java Source Code / Java DocumentationJava Source Code and Java Documentation

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Java Source Code / Java Documentation » Net » Ganymed SSH 2 » ch.ethz.ssh2.transport 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        package ch.ethz.ssh2.transport;
002:
003:        import java.io.IOException;
004:        import java.io.InputStream;
005:        import java.io.OutputStream;
006:        import java.net.InetAddress;
007:        import java.net.InetSocketAddress;
008:        import java.net.Socket;
009:        import java.net.UnknownHostException;
010:        import java.security.SecureRandom;
011:        import java.util.Vector;
012:
013:        import ch.ethz.ssh2.ConnectionInfo;
014:        import ch.ethz.ssh2.ConnectionMonitor;
015:        import ch.ethz.ssh2.DHGexParameters;
016:        import ch.ethz.ssh2.HTTPProxyData;
017:        import ch.ethz.ssh2.HTTPProxyException;
018:        import ch.ethz.ssh2.ProxyData;
019:        import ch.ethz.ssh2.ServerHostKeyVerifier;
020:        import ch.ethz.ssh2.crypto.Base64;
021:        import ch.ethz.ssh2.crypto.CryptoWishList;
022:        import ch.ethz.ssh2.crypto.cipher.BlockCipher;
023:        import ch.ethz.ssh2.crypto.digest.MAC;
024:        import ch.ethz.ssh2.log.Logger;
025:        import ch.ethz.ssh2.packets.PacketDisconnect;
026:        import ch.ethz.ssh2.packets.Packets;
027:        import ch.ethz.ssh2.packets.TypesReader;
028:        import ch.ethz.ssh2.util.Tokenizer;
029:
030:        /*
031:         * Yes, the "standard" is a big mess. On one side, the say that arbitary channel
032:         * packets are allowed during kex exchange, on the other side we need to blindly
033:         * ignore the next _packet_ if the KEX guess was wrong. Where do we know from that
034:         * the next packet is not a channel data packet? Yes, we could check if it is in
035:         * the KEX range. But the standard says nothing about this. The OpenSSH guys
036:         * block local "normal" traffic during KEX. That's fine - however, they assume
037:         * that the other side is doing the same. During re-key, if they receive traffic
038:         * other than KEX, they become horribly irritated and kill the connection. Since
039:         * we are very likely going to communicate with OpenSSH servers, we have to play
040:         * the same game - even though we could do better.
041:         * 
042:         * btw: having stdout and stderr on the same channel, with a shared window, is
043:         * also a VERY good idea... =(
044:         */
045:
046:        /**
047:         * TransportManager.
048:         * 
049:         * @author Christian Plattner, plattner@inf.ethz.ch
050:         * @version $Id: TransportManager.java,v 1.16 2006/08/11 12:24:00 cplattne Exp $
051:         */
052:        public class TransportManager {
053:            private static final Logger log = Logger
054:                    .getLogger(TransportManager.class);
055:
056:            class HandlerEntry {
057:                MessageHandler mh;
058:                int low;
059:                int high;
060:            }
061:
062:            private final Vector asynchronousQueue = new Vector();
063:            private Thread asynchronousThread = null;
064:
065:            class AsynchronousWorker extends Thread {
066:                public void run() {
067:                    while (true) {
068:                        byte[] msg = null;
069:
070:                        synchronized (asynchronousQueue) {
071:                            if (asynchronousQueue.size() == 0) {
072:                                /* After the queue is empty for about 2 seconds, stop this thread */
073:
074:                                try {
075:                                    asynchronousQueue.wait(2000);
076:                                } catch (InterruptedException e) {
077:                                    /* OKOK, if somebody interrupts us, then we may die earlier. */
078:                                }
079:
080:                                if (asynchronousQueue.size() == 0) {
081:                                    asynchronousThread = null;
082:                                    return;
083:                                }
084:                            }
085:
086:                            msg = (byte[]) asynchronousQueue.remove(0);
087:                        }
088:
089:                        /* The following invocation may throw an IOException.
090:                         * There is no point in handling it - it simply means
091:                         * that the connection has a problem and we should stop
092:                         * sending asynchronously messages. We do not need to signal that
093:                         * we have exited (asynchronousThread = null): further
094:                         * messages in the queue cannot be sent by this or any
095:                         * other thread.
096:                         * Other threads will sooner or later (when receiving or
097:                         * sending the next message) get the same IOException and
098:                         * get to the same conclusion.
099:                         */
100:
101:                        try {
102:                            sendMessage(msg);
103:                        } catch (IOException e) {
104:                            return;
105:                        }
106:                    }
107:                }
108:            }
109:
110:            String hostname;
111:            int port;
112:            final Socket sock = new Socket();
113:
114:            Object connectionSemaphore = new Object();
115:
116:            boolean flagKexOngoing = false;
117:            boolean connectionClosed = false;
118:
119:            Throwable reasonClosedCause = null;
120:
121:            TransportConnection tc;
122:            KexManager km;
123:
124:            Vector messageHandlers = new Vector();
125:
126:            Thread receiveThread;
127:
128:            Vector connectionMonitors = new Vector();
129:            boolean monitorsWereInformed = false;
130:
131:            /**
132:             * There were reports that there are JDKs which use
133:             * the resolver even though one supplies a dotted IP
134:             * address in the Socket constructor. That is why we
135:             * try to generate the InetAdress "by hand".
136:             * 
137:             * @param host
138:             * @return the InetAddress
139:             * @throws UnknownHostException
140:             */
141:            private InetAddress createInetAddress(String host)
142:                    throws UnknownHostException {
143:                /* Check if it is a dotted IP4 address */
144:
145:                InetAddress addr = parseIPv4Address(host);
146:
147:                if (addr != null)
148:                    return addr;
149:
150:                return InetAddress.getByName(host);
151:            }
152:
153:            private InetAddress parseIPv4Address(String host)
154:                    throws UnknownHostException {
155:                if (host == null)
156:                    return null;
157:
158:                String[] quad = Tokenizer.parseTokens(host, '.');
159:
160:                if ((quad == null) || (quad.length != 4))
161:                    return null;
162:
163:                byte[] addr = new byte[4];
164:
165:                for (int i = 0; i < 4; i++) {
166:                    int part = 0;
167:
168:                    if ((quad[i].length() == 0) || (quad[i].length() > 3))
169:                        return null;
170:
171:                    for (int k = 0; k < quad[i].length(); k++) {
172:                        char c = quad[i].charAt(k);
173:
174:                        /* No, Character.isDigit is not the same */
175:                        if ((c < '0') || (c > '9'))
176:                            return null;
177:
178:                        part = part * 10 + (c - '0');
179:                    }
180:
181:                    if (part > 255) /* 300.1.2.3 is invalid =) */
182:                        return null;
183:
184:                    addr[i] = (byte) part;
185:                }
186:
187:                return InetAddress.getByAddress(host, addr);
188:            }
189:
190:            public TransportManager(String host, int port) throws IOException {
191:                this .hostname = host;
192:                this .port = port;
193:            }
194:
195:            public int getPacketOverheadEstimate() {
196:                return tc.getPacketOverheadEstimate();
197:            }
198:
199:            public void setTcpNoDelay(boolean state) throws IOException {
200:                sock.setTcpNoDelay(state);
201:            }
202:
203:            public void setSoTimeout(int timeout) throws IOException {
204:                sock.setSoTimeout(timeout);
205:            }
206:
207:            public ConnectionInfo getConnectionInfo(int kexNumber)
208:                    throws IOException {
209:                return km.getOrWaitForConnectionInfo(kexNumber);
210:            }
211:
212:            public Throwable getReasonClosedCause() {
213:                synchronized (connectionSemaphore) {
214:                    return reasonClosedCause;
215:                }
216:            }
217:
218:            public byte[] getSessionIdentifier() {
219:                return km.sessionId;
220:            }
221:
222:            public void close(Throwable cause, boolean useDisconnectPacket) {
223:                if (useDisconnectPacket == false) {
224:                    /* OK, hard shutdown - do not aquire the semaphore,
225:                     * perhaps somebody is inside (and waits until the remote
226:                     * side is ready to accept new data). */
227:
228:                    try {
229:                        sock.close();
230:                    } catch (IOException ignore) {
231:                    }
232:
233:                    /* OK, whoever tried to send data, should now agree that
234:                     * there is no point in further waiting =)
235:                     * It is safe now to aquire the semaphore.
236:                     */
237:                }
238:
239:                synchronized (connectionSemaphore) {
240:                    if (connectionClosed == false) {
241:                        if (useDisconnectPacket == true) {
242:                            try {
243:                                byte[] msg = new PacketDisconnect(
244:                                        Packets.SSH_DISCONNECT_BY_APPLICATION,
245:                                        cause.getMessage(), "").getPayload();
246:                                if (tc != null)
247:                                    tc.sendMessage(msg);
248:                            } catch (IOException ignore) {
249:                            }
250:
251:                            try {
252:                                sock.close();
253:                            } catch (IOException ignore) {
254:                            }
255:                        }
256:
257:                        connectionClosed = true;
258:                        reasonClosedCause = cause; /* may be null */
259:                    }
260:                    connectionSemaphore.notifyAll();
261:                }
262:
263:                /* No check if we need to inform the monitors */
264:
265:                Vector monitors = null;
266:
267:                synchronized (this ) {
268:                    /* Short term lock to protect "connectionMonitors"
269:                     * and "monitorsWereInformed"
270:                     * (they may be modified concurrently)
271:                     */
272:
273:                    if (monitorsWereInformed == false) {
274:                        monitorsWereInformed = true;
275:                        monitors = (Vector) connectionMonitors.clone();
276:                    }
277:                }
278:
279:                if (monitors != null) {
280:                    for (int i = 0; i < monitors.size(); i++) {
281:                        try {
282:                            ConnectionMonitor cmon = (ConnectionMonitor) monitors
283:                                    .elementAt(i);
284:                            cmon.connectionLost(reasonClosedCause);
285:                        } catch (Exception ignore) {
286:                        }
287:                    }
288:                }
289:            }
290:
291:            private void establishConnection(ProxyData proxyData,
292:                    int connectTimeout) throws IOException {
293:                /* See the comment for createInetAddress() */
294:
295:                if (proxyData == null) {
296:                    InetAddress addr = createInetAddress(hostname);
297:                    sock.connect(new InetSocketAddress(addr, port),
298:                            connectTimeout);
299:                    sock.setSoTimeout(0);
300:                    return;
301:                }
302:
303:                if (proxyData instanceof  HTTPProxyData) {
304:                    HTTPProxyData pd = (HTTPProxyData) proxyData;
305:
306:                    /* At the moment, we only support HTTP proxies */
307:
308:                    InetAddress addr = createInetAddress(pd.proxyHost);
309:                    sock.connect(new InetSocketAddress(addr, pd.proxyPort),
310:                            connectTimeout);
311:                    sock.setSoTimeout(0);
312:
313:                    /* OK, now tell the proxy where we actually want to connect to */
314:
315:                    StringBuffer sb = new StringBuffer();
316:
317:                    sb.append("CONNECT ");
318:                    sb.append(hostname);
319:                    sb.append(':');
320:                    sb.append(port);
321:                    sb.append(" HTTP/1.0\r\n");
322:
323:                    if ((pd.proxyUser != null) && (pd.proxyPass != null)) {
324:                        String credentials = pd.proxyUser + ":" + pd.proxyPass;
325:                        char[] encoded = Base64.encode(credentials.getBytes());
326:                        sb.append("Proxy-Authorization: Basic ");
327:                        sb.append(encoded);
328:                        sb.append("\r\n");
329:                    }
330:
331:                    if (pd.requestHeaderLines != null) {
332:                        for (int i = 0; i < pd.requestHeaderLines.length; i++) {
333:                            if (pd.requestHeaderLines[i] != null) {
334:                                sb.append(pd.requestHeaderLines[i]);
335:                                sb.append("\r\n");
336:                            }
337:                        }
338:                    }
339:
340:                    sb.append("\r\n");
341:
342:                    OutputStream out = sock.getOutputStream();
343:
344:                    out.write(sb.toString().getBytes());
345:                    out.flush();
346:
347:                    /* Now parse the HTTP response */
348:
349:                    byte[] buffer = new byte[1024];
350:                    InputStream in = sock.getInputStream();
351:
352:                    int len = ClientServerHello.readLineRN(in, buffer);
353:
354:                    String httpReponse = new String(buffer, 0, len);
355:
356:                    if (httpReponse.startsWith("HTTP/") == false)
357:                        throw new IOException(
358:                                "The proxy did not send back a valid HTTP response.");
359:
360:                    /* "HTTP/1.X XYZ X" => 14 characters minimum */
361:
362:                    if ((httpReponse.length() < 14)
363:                            || (httpReponse.charAt(8) != ' ')
364:                            || (httpReponse.charAt(12) != ' '))
365:                        throw new IOException(
366:                                "The proxy did not send back a valid HTTP response.");
367:
368:                    int errorCode = 0;
369:
370:                    try {
371:                        errorCode = Integer.parseInt(httpReponse.substring(9,
372:                                12));
373:                    } catch (NumberFormatException ignore) {
374:                        throw new IOException(
375:                                "The proxy did not send back a valid HTTP response.");
376:                    }
377:
378:                    if ((errorCode < 0) || (errorCode > 999))
379:                        throw new IOException(
380:                                "The proxy did not send back a valid HTTP response.");
381:
382:                    if (errorCode != 200) {
383:                        throw new HTTPProxyException(httpReponse.substring(13),
384:                                errorCode);
385:                    }
386:
387:                    /* OK, read until empty line */
388:
389:                    while (true) {
390:                        len = ClientServerHello.readLineRN(in, buffer);
391:                        if (len == 0)
392:                            break;
393:                    }
394:                    return;
395:                }
396:
397:                throw new IOException("Unsupported ProxyData");
398:            }
399:
400:            public void initialize(CryptoWishList cwl,
401:                    ServerHostKeyVerifier verifier, DHGexParameters dhgex,
402:                    int connectTimeout, SecureRandom rnd, ProxyData proxyData)
403:                    throws IOException {
404:                /* First, establish the TCP connection to the SSH-2 server */
405:
406:                establishConnection(proxyData, connectTimeout);
407:
408:                /* Parse the server line and say hello - important: this information is later needed for the
409:                 * key exchange (to stop man-in-the-middle attacks) - that is why we wrap it into an object
410:                 * for later use.
411:                 */
412:
413:                ClientServerHello csh = new ClientServerHello(sock
414:                        .getInputStream(), sock.getOutputStream());
415:
416:                tc = new TransportConnection(sock.getInputStream(), sock
417:                        .getOutputStream(), rnd);
418:
419:                km = new KexManager(this , csh, cwl, hostname, port, verifier,
420:                        rnd);
421:                km.initiateKEX(cwl, dhgex);
422:
423:                receiveThread = new Thread(new Runnable() {
424:                    public void run() {
425:                        try {
426:                            receiveLoop();
427:                        } catch (IOException e) {
428:                            close(e, false);
429:
430:                            if (log.isEnabled())
431:                                log.log(10,
432:                                        "Receive thread: error in receiveLoop: "
433:                                                + e.getMessage());
434:                        }
435:
436:                        if (log.isEnabled())
437:                            log
438:                                    .log(50,
439:                                            "Receive thread: back from receiveLoop");
440:
441:                        /* Tell all handlers that it is time to say goodbye */
442:
443:                        if (km != null) {
444:                            try {
445:                                km.handleMessage(null, 0);
446:                            } catch (IOException e) {
447:                            }
448:                        }
449:
450:                        for (int i = 0; i < messageHandlers.size(); i++) {
451:                            HandlerEntry he = (HandlerEntry) messageHandlers
452:                                    .elementAt(i);
453:                            try {
454:                                he.mh.handleMessage(null, 0);
455:                            } catch (Exception ignore) {
456:                            }
457:                        }
458:                    }
459:                });
460:
461:                receiveThread.setDaemon(true);
462:                receiveThread.start();
463:            }
464:
465:            public void registerMessageHandler(MessageHandler mh, int low,
466:                    int high) {
467:                HandlerEntry he = new HandlerEntry();
468:                he.mh = mh;
469:                he.low = low;
470:                he.high = high;
471:
472:                synchronized (messageHandlers) {
473:                    messageHandlers.addElement(he);
474:                }
475:            }
476:
477:            public void removeMessageHandler(MessageHandler mh, int low,
478:                    int high) {
479:                synchronized (messageHandlers) {
480:                    for (int i = 0; i < messageHandlers.size(); i++) {
481:                        HandlerEntry he = (HandlerEntry) messageHandlers
482:                                .elementAt(i);
483:                        if ((he.mh == mh) && (he.low == low)
484:                                && (he.high == high)) {
485:                            messageHandlers.removeElementAt(i);
486:                            break;
487:                        }
488:                    }
489:                }
490:            }
491:
492:            public void sendKexMessage(byte[] msg) throws IOException {
493:                synchronized (connectionSemaphore) {
494:                    if (connectionClosed) {
495:                        throw (IOException) new IOException(
496:                                "Sorry, this connection is closed.")
497:                                .initCause(reasonClosedCause);
498:                    }
499:
500:                    flagKexOngoing = true;
501:
502:                    try {
503:                        tc.sendMessage(msg);
504:                    } catch (IOException e) {
505:                        close(e, false);
506:                        throw e;
507:                    }
508:                }
509:            }
510:
511:            public void kexFinished() throws IOException {
512:                synchronized (connectionSemaphore) {
513:                    flagKexOngoing = false;
514:                    connectionSemaphore.notifyAll();
515:                }
516:            }
517:
518:            public void forceKeyExchange(CryptoWishList cwl,
519:                    DHGexParameters dhgex) throws IOException {
520:                km.initiateKEX(cwl, dhgex);
521:            }
522:
523:            public void changeRecvCipher(BlockCipher bc, MAC mac) {
524:                tc.changeRecvCipher(bc, mac);
525:            }
526:
527:            public void changeSendCipher(BlockCipher bc, MAC mac) {
528:                tc.changeSendCipher(bc, mac);
529:            }
530:
531:            public void sendAsynchronousMessage(byte[] msg) throws IOException {
532:                synchronized (asynchronousQueue) {
533:                    asynchronousQueue.addElement(msg);
534:
535:                    /* This limit should be flexible enough. We need this, otherwise the peer
536:                     * can flood us with global requests (and other stuff where we have to reply
537:                     * with an asynchronous message) and (if the server just sends data and does not
538:                     * read what we send) this will probably put us in a low memory situation
539:                     * (our send queue would grow and grow and...) */
540:
541:                    if (asynchronousQueue.size() > 100)
542:                        throw new IOException(
543:                                "Error: the peer is not consuming our asynchronous replies.");
544:
545:                    /* Check if we have an asynchronous sending thread */
546:
547:                    if (asynchronousThread == null) {
548:                        asynchronousThread = new AsynchronousWorker();
549:                        asynchronousThread.setDaemon(true);
550:                        asynchronousThread.start();
551:
552:                        /* The thread will stop after 2 seconds of inactivity (i.e., empty queue) */
553:                    }
554:                }
555:            }
556:
557:            public void setConnectionMonitors(Vector monitors) {
558:                synchronized (this ) {
559:                    connectionMonitors = (Vector) monitors.clone();
560:                }
561:            }
562:
563:            public void sendMessage(byte[] msg) throws IOException {
564:                if (Thread.currentThread() == receiveThread)
565:                    throw new IOException(
566:                            "Assertion error: sendMessage may never be invoked by the receiver thread!");
567:
568:                synchronized (connectionSemaphore) {
569:                    while (true) {
570:                        if (connectionClosed) {
571:                            throw (IOException) new IOException(
572:                                    "Sorry, this connection is closed.")
573:                                    .initCause(reasonClosedCause);
574:                        }
575:
576:                        if (flagKexOngoing == false)
577:                            break;
578:
579:                        try {
580:                            connectionSemaphore.wait();
581:                        } catch (InterruptedException e) {
582:                        }
583:                    }
584:
585:                    try {
586:                        tc.sendMessage(msg);
587:                    } catch (IOException e) {
588:                        close(e, false);
589:                        throw e;
590:                    }
591:                }
592:            }
593:
594:            public void receiveLoop() throws IOException {
595:                byte[] msg = new byte[35000];
596:
597:                while (true) {
598:                    int msglen = tc.receiveMessage(msg, 0, msg.length);
599:
600:                    int type = msg[0] & 0xff;
601:
602:                    if (type == Packets.SSH_MSG_IGNORE)
603:                        continue;
604:
605:                    if (type == Packets.SSH_MSG_DEBUG) {
606:                        if (log.isEnabled()) {
607:                            TypesReader tr = new TypesReader(msg, 0, msglen);
608:                            tr.readByte();
609:                            tr.readBoolean();
610:                            StringBuffer debugMessageBuffer = new StringBuffer();
611:                            debugMessageBuffer.append(tr.readString("UTF-8"));
612:
613:                            for (int i = 0; i < debugMessageBuffer.length(); i++) {
614:                                char c = debugMessageBuffer.charAt(i);
615:
616:                                if ((c >= 32) && (c <= 126))
617:                                    continue;
618:                                debugMessageBuffer.setCharAt(i, '\uFFFD');
619:                            }
620:
621:                            log.log(50, "DEBUG Message from remote: '"
622:                                    + debugMessageBuffer.toString() + "'");
623:                        }
624:                        continue;
625:                    }
626:
627:                    if (type == Packets.SSH_MSG_UNIMPLEMENTED) {
628:                        throw new IOException(
629:                                "Peer sent UNIMPLEMENTED message, that should not happen.");
630:                    }
631:
632:                    if (type == Packets.SSH_MSG_DISCONNECT) {
633:                        TypesReader tr = new TypesReader(msg, 0, msglen);
634:                        tr.readByte();
635:                        int reason_code = tr.readUINT32();
636:                        StringBuffer reasonBuffer = new StringBuffer();
637:                        reasonBuffer.append(tr.readString("UTF-8"));
638:
639:                        /*
640:                         * Do not get fooled by servers that send abnormal long error
641:                         * messages
642:                         */
643:
644:                        if (reasonBuffer.length() > 255) {
645:                            reasonBuffer.setLength(255);
646:                            reasonBuffer.setCharAt(254, '.');
647:                            reasonBuffer.setCharAt(253, '.');
648:                            reasonBuffer.setCharAt(252, '.');
649:                        }
650:
651:                        /*
652:                         * Also, check that the server did not send charcaters that may
653:                         * screw up the receiver -> restrict to reasonable US-ASCII
654:                         * subset -> "printable characters" (ASCII 32 - 126). Replace
655:                         * all others with 0xFFFD (UNICODE replacement character).
656:                         */
657:
658:                        for (int i = 0; i < reasonBuffer.length(); i++) {
659:                            char c = reasonBuffer.charAt(i);
660:
661:                            if ((c >= 32) && (c <= 126))
662:                                continue;
663:                            reasonBuffer.setCharAt(i, '\uFFFD');
664:                        }
665:
666:                        throw new IOException(
667:                                "Peer sent DISCONNECT message (reason code "
668:                                        + reason_code + "): "
669:                                        + reasonBuffer.toString());
670:                    }
671:
672:                    /*
673:                     * Is it a KEX Packet?
674:                     */
675:
676:                    if ((type == Packets.SSH_MSG_KEXINIT)
677:                            || (type == Packets.SSH_MSG_NEWKEYS)
678:                            || ((type >= 30) && (type <= 49))) {
679:                        km.handleMessage(msg, msglen);
680:                        continue;
681:                    }
682:
683:                    MessageHandler mh = null;
684:
685:                    for (int i = 0; i < messageHandlers.size(); i++) {
686:                        HandlerEntry he = (HandlerEntry) messageHandlers
687:                                .elementAt(i);
688:                        if ((he.low <= type) && (type <= he.high)) {
689:                            mh = he.mh;
690:                            break;
691:                        }
692:                    }
693:
694:                    if (mh == null)
695:                        throw new IOException("Unexpected SSH message (type "
696:                                + type + ")");
697:
698:                    mh.handleMessage(msg, msglen);
699:                }
700:            }
701:        }
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