Update Trilead SSH-2 for Java from build 211 to build 213

1 files changed, 383 insertions, 241 deletions

diff --git a/src/com/trilead/ssh2/Connection.java b/src/com/trilead/ssh2/Connection.java
index acc8395..38b96c5 100644
--- a/src/com/trilead/ssh2/Connection.java
+++ b/src/com/trilead/ssh2/Connection.java
@@ -15,6 +15,7 @@ import com.trilead.ssh2.channel.ChannelManager;
 import com.trilead.ssh2.crypto.CryptoWishList;

 import com.trilead.ssh2.crypto.cipher.BlockCipherFactory;

 import com.trilead.ssh2.crypto.digest.MAC;

+import com.trilead.ssh2.log.Logger;

 import com.trilead.ssh2.packets.PacketIgnore;

 import com.trilead.ssh2.transport.KexManager;

 import com.trilead.ssh2.transport.TransportManager;

@@ -29,13 +30,16 @@ import com.trilead.ssh2.util.TimeoutService.TimeoutToken;
  * <ol>

  * <li>creates a {@link #Connection(String) Connection} object.</li>

  * <li>calls the {@link #connect() connect()} method.</li>

- * <li>calls some of the authentication methods (e.g., {@link #authenticateWithPublicKey(String, File, String) authenticateWithPublicKey()}).</li>

- * <li>calls one or several times the {@link #openSession() openSession()} method.</li>

- * <li>finally, one must close the connection and release resources with the {@link #close() close()} method.</li>

+ * <li>calls some of the authentication methods (e.g.,

+ * {@link #authenticateWithPublicKey(String, File, String) authenticateWithPublicKey()}).</li>

+ * <li>calls one or several times the {@link #openSession() openSession()}

+ * method.</li>

+ * <li>finally, one must close the connection and release resources with the

+ * {@link #close() close()} method.</li>

  * </ol>

  * 

  * @author Christian Plattner, plattner@trilead.com

- * @version $Id: Connection.java,v 1.1 2007/10/15 12:49:56 cplattne Exp $

+ * @version $Id: Connection.java,v 1.3 2008/04/01 12:38:09 cplattne Exp $

  */

 

 public class Connection

@@ -43,12 +47,12 @@ public class Connection
 	/**

 	 * The identifier presented to the SSH-2 server.

 	 */

-	public final static String identification = "TrileadSSH2Java_211";

+	public final static String identification = "TrileadSSH2Java_213";

 

-	/* Will be used to generate all random data needed for the current connection.

-	 * Note: SecureRandom.nextBytes() is thread safe.

+	/**

+	 * Will be used to generate all random data needed for the current

+	 * connection. Note: SecureRandom.nextBytes() is thread safe.

 	 */

-

 	private SecureRandom generator;

 

 	/**

@@ -74,7 +78,8 @@ public class Connection
 	/**

 	 * Unless you know what you are doing, you will never need this.

 	 * 

-	 * @return The list of supported server host key algorthims by this implementation.

+	 * @return The list of supported server host key algorthims by this

+	 *         implementation.

 	 */

 	public static synchronized String[] getAvailableServerHostKeyAlgorithms()

 	{

@@ -106,9 +111,10 @@ public class Connection
 	 * Prepares a fresh <code>Connection</code> object which can then be used

 	 * to establish a connection to the specified SSH-2 server.

 	 * <p>

-	 * Same as {@link #Connection(String, int) Connection(hostname, 22)}. 

+	 * Same as {@link #Connection(String, int) Connection(hostname, 22)}.

 	 * 

-	 * @param hostname the hostname of the SSH-2 server.

+	 * @param hostname

+	 *            the hostname of the SSH-2 server.

 	 */

 	public Connection(String hostname)

 	{

@@ -156,9 +162,10 @@ public class Connection
 	 * @return whether the connection is now authenticated.

 	 * @throws IOException

 	 * 

-	 * @deprecated You should use one of the {@link #authenticateWithPublicKey(String, File, String) authenticateWithPublicKey()}

-	 * 		      methods, this method is just a wrapper for it and will

-	 *            disappear in future builds.

+	 * @deprecated You should use one of the

+	 *             {@link #authenticateWithPublicKey(String, File, String) authenticateWithPublicKey()}

+	 *             methods, this method is just a wrapper for it and will

+	 *             disappear in future builds.

 	 * 

 	 */

 	public synchronized boolean authenticateWithDSA(String user, String pem, String password) throws IOException

@@ -187,8 +194,10 @@ public class Connection
 	}

 

 	/**

-	 * A wrapper that calls {@link #authenticateWithKeyboardInteractive(String, String[], InteractiveCallback)

-	 * authenticateWithKeyboardInteractivewith} a <code>null</code> submethod list.

+	 * A wrapper that calls

+	 * {@link #authenticateWithKeyboardInteractive(String, String[], InteractiveCallback)

+	 * authenticateWithKeyboardInteractivewith} a <code>null</code> submethod

+	 * list.

 	 * 

 	 * @param user

 	 *            A <code>String</code> holding the username.

@@ -276,12 +285,14 @@ public class Connection
 	 * the remaining possible methods).

 	 * <p>

 	 * Note: if this method fails, then please double-check that it is actually

-	 * offered by the server (use {@link #getRemainingAuthMethods(String) getRemainingAuthMethods()}.

+	 * offered by the server (use

+	 * {@link #getRemainingAuthMethods(String) getRemainingAuthMethods()}.

 	 * <p>

-	 * Often, password authentication is disabled, but users are not aware of it.

-	 * Many servers only offer "publickey" and "keyboard-interactive". However,

-	 * even though "keyboard-interactive" *feels* like password authentication

-	 * (e.g., when using the putty or openssh clients) it is *not* the same mechanism.

+	 * Often, password authentication is disabled, but users are not aware of

+	 * it. Many servers only offer "publickey" and "keyboard-interactive".

+	 * However, even though "keyboard-interactive" *feels* like password

+	 * authentication (e.g., when using the putty or openssh clients) it is

+	 * *not* the same mechanism.

 	 * 

 	 * @param user

 	 * @param password

@@ -314,26 +325,26 @@ public class Connection
 	}

 

 	/**

-	 * After a successful connect, one has to authenticate oneself.

-	 * This method can be used to explicitly use the special "none"

-	 * authentication method (where only a username has to be specified).

+	 * After a successful connect, one has to authenticate oneself. This method

+	 * can be used to explicitly use the special "none" authentication method

+	 * (where only a username has to be specified).

 	 * <p>

 	 * Note 1: The "none" method may always be tried by clients, however as by

 	 * the specs, the server will not explicitly announce it. In other words,

 	 * the "none" token will never show up in the list returned by

 	 * {@link #getRemainingAuthMethods(String)}.

 	 * <p>

-	 * Note 2: no matter which one of the authenticateWithXXX() methods

-	 * you call, the library will always issue exactly one initial "none"

+	 * Note 2: no matter which one of the authenticateWithXXX() methods you

+	 * call, the library will always issue exactly one initial "none"

 	 * authentication request to retrieve the initially allowed list of

 	 * authentication methods by the server. Please read RFC 4252 for the

 	 * details.

 	 * <p>

 	 * If the authentication phase is complete, <code>true</code> will be

 	 * returned. If further authentication steps are needed, <code>false</code>

-	 * is returned and one can retry by any other authentication method

-	 * (use the <code>getRemainingAuthMethods</code> method to get a list of

-	 * the remaining possible methods).

+	 * is returned and one can retry by any other authentication method (use the

+	 * <code>getRemainingAuthMethods</code> method to get a list of the

+	 * remaining possible methods).

 	 * 

 	 * @param user

 	 * @return if the connection is now authenticated.

@@ -357,7 +368,7 @@ public class Connection
 			throw new IllegalArgumentException("user argument is null");

 

 		/* Trigger the sending of the PacketUserauthRequestNone packet */

-		/* (if not already done)                                       */

+		/* (if not already done) */

 

 		authenticated = am.authenticateNone(user);

 

@@ -365,18 +376,19 @@ public class Connection
 	}

 

 	/**

-	 * After a successful connect, one has to authenticate oneself.

-	 * The authentication method "publickey" works by signing a challenge

-	 * sent by the server. The signature is either DSA or RSA based - it

-	 * just depends on the type of private key you specify, either a DSA

-	 * or RSA private key in PEM format. And yes, this is may seem to be a

-	 * little confusing, the method is called "publickey" in the SSH-2 protocol

-	 * specification, however since we need to generate a signature, you

-	 * actually have to supply a private key =).

+	 * After a successful connect, one has to authenticate oneself. The

+	 * authentication method "publickey" works by signing a challenge sent by

+	 * the server. The signature is either DSA or RSA based - it just depends on

+	 * the type of private key you specify, either a DSA or RSA private key in

+	 * PEM format. And yes, this is may seem to be a little confusing, the

+	 * method is called "publickey" in the SSH-2 protocol specification, however

+	 * since we need to generate a signature, you actually have to supply a

+	 * private key =).

 	 * <p>

-	 * The private key contained in the PEM file may also be encrypted ("Proc-Type: 4,ENCRYPTED").

-	 * The library supports DES-CBC and DES-EDE3-CBC encryption, as well

-	 * as the more exotic PEM encrpytions AES-128-CBC, AES-192-CBC and AES-256-CBC.

+	 * The private key contained in the PEM file may also be encrypted

+	 * ("Proc-Type: 4,ENCRYPTED"). The library supports DES-CBC and DES-EDE3-CBC

+	 * encryption, as well as the more exotic PEM encrpytions AES-128-CBC,

+	 * AES-192-CBC and AES-256-CBC.

 	 * <p>

 	 * If the authentication phase is complete, <code>true</code> will be

 	 * returned. If the server does not accept the request (or if further

@@ -385,23 +397,24 @@ public class Connection
 	 * (use the <code>getRemainingAuthMethods</code> method to get a list of

 	 * the remaining possible methods).

 	 * <p>

-	 * NOTE PUTTY USERS: Event though your key file may start with "-----BEGIN..."

-	 * it is not in the expected format. You have to convert it to the OpenSSH

-	 * key format by using the "puttygen" tool (can be downloaded from the Putty

-	 * website). Simply load your key and then use the "Conversions/Export OpenSSH key"

-	 * functionality to get a proper PEM file.

+	 * NOTE PUTTY USERS: Event though your key file may start with

+	 * "-----BEGIN..." it is not in the expected format. You have to convert it

+	 * to the OpenSSH key format by using the "puttygen" tool (can be downloaded

+	 * from the Putty website). Simply load your key and then use the

+	 * "Conversions/Export OpenSSH key" functionality to get a proper PEM file.

 	 * 

 	 * @param user

 	 *            A <code>String</code> holding the username.

 	 * @param pemPrivateKey

-	 *            A <code>char[]</code> containing a DSA or RSA private key of the

-	 *            user in OpenSSH key format (PEM, you can't miss the

-	 *            "-----BEGIN DSA PRIVATE KEY-----" or "-----BEGIN RSA PRIVATE KEY-----"

-	 *            tag). The char array may contain linebreaks/linefeeds.

+	 *            A <code>char[]</code> containing a DSA or RSA private key of

+	 *            the user in OpenSSH key format (PEM, you can't miss the

+	 *            "-----BEGIN DSA PRIVATE KEY-----" or "-----BEGIN RSA PRIVATE

+	 *            KEY-----" tag). The char array may contain

+	 *            linebreaks/linefeeds.

 	 * @param password

-	 *            If the PEM structure is encrypted ("Proc-Type: 4,ENCRYPTED") then

-	 *            you must specify a password. Otherwise, this argument will be ignored

-	 *            and can be set to <code>null</code>.

+	 *            If the PEM structure is encrypted ("Proc-Type: 4,ENCRYPTED")

+	 *            then you must specify a password. Otherwise, this argument

+	 *            will be ignored and can be set to <code>null</code>.

 	 * 

 	 * @return whether the connection is now authenticated.

 	 * @throws IOException

@@ -433,25 +446,27 @@ public class Connection
 	}

 

 	/**

-	 * A convenience wrapper function which reads in a private key (PEM format, either DSA or RSA)

-	 * and then calls <code>authenticateWithPublicKey(String, char[], String)</code>.

+	 * A convenience wrapper function which reads in a private key (PEM format,

+	 * either DSA or RSA) and then calls

+	 * <code>authenticateWithPublicKey(String, char[], String)</code>.

 	 * <p>

-	 * NOTE PUTTY USERS: Event though your key file may start with "-----BEGIN..."

-	 * it is not in the expected format. You have to convert it to the OpenSSH

-	 * key format by using the "puttygen" tool (can be downloaded from the Putty

-	 * website). Simply load your key and then use the "Conversions/Export OpenSSH key"

-	 * functionality to get a proper PEM file.

+	 * NOTE PUTTY USERS: Event though your key file may start with

+	 * "-----BEGIN..." it is not in the expected format. You have to convert it

+	 * to the OpenSSH key format by using the "puttygen" tool (can be downloaded

+	 * from the Putty website). Simply load your key and then use the

+	 * "Conversions/Export OpenSSH key" functionality to get a proper PEM file.

 	 * 

 	 * @param user

 	 *            A <code>String</code> holding the username.

 	 * @param pemFile

-	 *            A <code>File</code> object pointing to a file containing a DSA or RSA

-	 *            private key of the user in OpenSSH key format (PEM, you can't miss the

-	 *            "-----BEGIN DSA PRIVATE KEY-----" or "-----BEGIN RSA PRIVATE KEY-----"

-	 *            tag).

+	 *            A <code>File</code> object pointing to a file containing a

+	 *            DSA or RSA private key of the user in OpenSSH key format (PEM,

+	 *            you can't miss the "-----BEGIN DSA PRIVATE KEY-----" or

+	 *            "-----BEGIN RSA PRIVATE KEY-----" tag).

 	 * @param password

-	 *            If the PEM file is encrypted then you must specify the password.

-	 *            Otherwise, this argument will be ignored and can be set to <code>null</code>.

+	 *            If the PEM file is encrypted then you must specify the

+	 *            password. Otherwise, this argument will be ignored and can be

+	 *            set to <code>null</code>.

 	 * 

 	 * @return whether the connection is now authenticated.

 	 * @throws IOException

@@ -482,17 +497,19 @@ public class Connection
 	}

 

 	/**

-	 * Add a {@link ConnectionMonitor} to this connection. Can be invoked at any time,

-	 * but it is best to add connection monitors before invoking

-	 * <code>connect()</code> to avoid glitches (e.g., you add a connection monitor after

-	 * a successful connect(), but the connection has died in the mean time. Then,

-	 * your connection monitor won't be notified.) 

+	 * Add a {@link ConnectionMonitor} to this connection. Can be invoked at any

+	 * time, but it is best to add connection monitors before invoking

+	 * <code>connect()</code> to avoid glitches (e.g., you add a connection

+	 * monitor after a successful connect(), but the connection has died in the

+	 * mean time. Then, your connection monitor won't be notified.)

 	 * <p>

 	 * You can add as many monitors as you like.

 	 * 

 	 * @see ConnectionMonitor

 	 * 

-	 * @param cmon An object implementing the <code>ConnectionMonitor</code> interface.

+	 * @param cmon

+	 *            An object implementing the <code>ConnectionMonitor</code>

+	 *            interface.

 	 */

 	public synchronized void addConnectionMonitor(ConnectionMonitor cmon)

 	{

@@ -533,9 +550,12 @@ public class Connection
 	}

 

 	/**

-	 * Same as {@link #connect(ServerHostKeyVerifier, int, int) connect(null, 0, 0)}.

+	 * Same as

+	 * {@link #connect(ServerHostKeyVerifier, int, int) connect(null, 0, 0)}.

 	 * 

-	 * @return see comments for the {@link #connect(ServerHostKeyVerifier, int, int) connect(ServerHostKeyVerifier, int, int)} method.

+	 * @return see comments for the

+	 *         {@link #connect(ServerHostKeyVerifier, int, int) connect(ServerHostKeyVerifier, int, int)}

+	 *         method.

 	 * @throws IOException

 	 */

 	public synchronized ConnectionInfo connect() throws IOException

@@ -544,9 +564,12 @@ public class Connection
 	}

 

 	/**

-	 * Same as {@link #connect(ServerHostKeyVerifier, int, int) connect(verifier, 0, 0)}.

+	 * Same as

+	 * {@link #connect(ServerHostKeyVerifier, int, int) connect(verifier, 0, 0)}.

 	 * 

-	 * @return see comments for the {@link #connect(ServerHostKeyVerifier, int, int) connect(ServerHostKeyVerifier, int, int)} method.

+	 * @return see comments for the

+	 *         {@link #connect(ServerHostKeyVerifier, int, int) connect(ServerHostKeyVerifier, int, int)}

+	 *         method.

 	 * @throws IOException

 	 */

 	public synchronized ConnectionInfo connect(ServerHostKeyVerifier verifier) throws IOException

@@ -556,74 +579,85 @@ public class Connection
 

 	/**

 	 * Connect to the SSH-2 server and, as soon as the server has presented its

-	 * host key, use the {@link ServerHostKeyVerifier#verifyServerHostKey(String,

-	 * int, String, byte[]) ServerHostKeyVerifier.verifyServerHostKey()}

-	 * method of the <code>verifier</code> to ask for permission to proceed.

-	 * If <code>verifier</code> is <code>null</code>, then any host key will be

-	 * accepted - this is NOT recommended, since it makes man-in-the-middle attackes

-	 * VERY easy (somebody could put a proxy SSH server between you and the real server).

+	 * host key, use the

+	 * {@link ServerHostKeyVerifier#verifyServerHostKey(String, int, String,

+	 * byte[]) ServerHostKeyVerifier.verifyServerHostKey()} method of the

+	 * <code>verifier</code> to ask for permission to proceed. If

+	 * <code>verifier</code> is <code>null</code>, then any host key will

+	 * be accepted - this is NOT recommended, since it makes man-in-the-middle

+	 * attackes VERY easy (somebody could put a proxy SSH server between you and

+	 * the real server).

 	 * <p>

 	 * Note: The verifier will be called before doing any crypto calculations

-	 * (i.e., diffie-hellman). Therefore, if you don't like the presented host key then

-	 * no CPU cycles are wasted (and the evil server has less information about us).

+	 * (i.e., diffie-hellman). Therefore, if you don't like the presented host

+	 * key then no CPU cycles are wasted (and the evil server has less

+	 * information about us).

 	 * <p>

-	 * However, it is still possible that the server presented a fake host key: the server

-	 * cheated (typically a sign for a man-in-the-middle attack) and is not able to generate

-	 * a signature that matches its host key. Don't worry, the library will detect such

-	 * a scenario later when checking the signature (the signature cannot be checked before

-	 * having completed the diffie-hellman exchange).

+	 * However, it is still possible that the server presented a fake host key:

+	 * the server cheated (typically a sign for a man-in-the-middle attack) and

+	 * is not able to generate a signature that matches its host key. Don't

+	 * worry, the library will detect such a scenario later when checking the

+	 * signature (the signature cannot be checked before having completed the

+	 * diffie-hellman exchange).

 	 * <p>

-	 * Note 2: The  {@link ServerHostKeyVerifier#verifyServerHostKey(String,

-	 * int, String, byte[]) ServerHostKeyVerifier.verifyServerHostKey()} method

-	 * will *NOT* be called from the current thread, the call is being made from a

+	 * Note 2: The {@link ServerHostKeyVerifier#verifyServerHostKey(String, int,

+	 * String, byte[]) ServerHostKeyVerifier.verifyServerHostKey()} method will

+	 * *NOT* be called from the current thread, the call is being made from a

 	 * background thread (there is a background dispatcher thread for every

-	 * established connection). 

+	 * established connection).

 	 * <p>

-	 * Note 3: This method will block as long as the key exchange of the underlying connection

-	 * has not been completed (and you have not specified any timeouts).

+	 * Note 3: This method will block as long as the key exchange of the

+	 * underlying connection has not been completed (and you have not specified

+	 * any timeouts).

 	 * <p>

-	 * Note 4: If you want to re-use a connection object that was successfully connected,

-	 * then you must call the {@link #close()} method before invoking <code>connect()</code> again.

+	 * Note 4: If you want to re-use a connection object that was successfully

+	 * connected, then you must call the {@link #close()} method before invoking

+	 * <code>connect()</code> again.

 	 * 

 	 * @param verifier

-	 *            An object that implements the

-	 *            {@link ServerHostKeyVerifier} interface. Pass <code>null</code>

-	 *            to accept any server host key - NOT recommended.

-	 *            

+	 *            An object that implements the {@link ServerHostKeyVerifier}

+	 *            interface. Pass <code>null</code> to accept any server host

+	 *            key - NOT recommended.

+	 * 

 	 * @param connectTimeout

-	 *            Connect the underlying TCP socket to the server with the given timeout

-	 *            value (non-negative, in milliseconds). Zero means no timeout. If a proxy is being

-	 *            used (see {@link #setProxyData(ProxyData)}), then this timeout is used for the

-	 *            connection establishment to the proxy.

+	 *            Connect the underlying TCP socket to the server with the given

+	 *            timeout value (non-negative, in milliseconds). Zero means no

+	 *            timeout. If a proxy is being used (see

+	 *            {@link #setProxyData(ProxyData)}), then this timeout is used

+	 *            for the connection establishment to the proxy.

 	 * 

 	 * @param kexTimeout

 	 *            Timeout for complete connection establishment (non-negative,

-	 *            in milliseconds). Zero means no timeout. The timeout counts from the

-	 *            moment you invoke the connect() method and is cancelled as soon as the

-	 *            first key-exchange round has finished. It is possible that

-	 *            the timeout event will be fired during the invocation of the

-	 *            <code>verifier</code> callback, but it will only have an effect after

-	 *            the <code>verifier</code> returns.

-	 *            

-	 * @return A {@link ConnectionInfo} object containing the details of

-	 *            the established connection.

-	 *         

+	 *            in milliseconds). Zero means no timeout. The timeout counts

+	 *            from the moment you invoke the connect() method and is

+	 *            cancelled as soon as the first key-exchange round has

+	 *            finished. It is possible that the timeout event will be fired

+	 *            during the invocation of the <code>verifier</code> callback,

+	 *            but it will only have an effect after the

+	 *            <code>verifier</code> returns.

+	 * 

+	 * @return A {@link ConnectionInfo} object containing the details of the

+	 *         established connection.

+	 * 

 	 * @throws IOException

-	 *            If any problem occurs, e.g., the server's host key is not

-	 *            accepted by the <code>verifier</code> or there is problem during

-	 *            the initial crypto setup (e.g., the signature sent by the server is wrong).

-	 *            <p>

-	 *            In case of a timeout (either connectTimeout or kexTimeout)

-	 *            a SocketTimeoutException is thrown.

-	 *            <p>

-	 *            An exception may also be thrown if the connection was already successfully

-	 *            connected (no matter if the connection broke in the mean time) and you invoke

-	 *            <code>connect()</code> again without having called {@link #close()} first.

-	 *            <p>

-	 *            If a HTTP proxy is being used and the proxy refuses the connection,

-	 *            then a {@link HTTPProxyException} may be thrown, which

-	 *            contains the details returned by the proxy. If the proxy is buggy and does

-	 *            not return a proper HTTP response, then a normal IOException is thrown instead.        

+	 *             If any problem occurs, e.g., the server's host key is not

+	 *             accepted by the <code>verifier</code> or there is problem

+	 *             during the initial crypto setup (e.g., the signature sent by

+	 *             the server is wrong).

+	 *             <p>

+	 *             In case of a timeout (either connectTimeout or kexTimeout) a

+	 *             SocketTimeoutException is thrown.

+	 *             <p>

+	 *             An exception may also be thrown if the connection was already

+	 *             successfully connected (no matter if the connection broke in

+	 *             the mean time) and you invoke <code>connect()</code> again

+	 *             without having called {@link #close()} first.

+	 *             <p>

+	 *             If a HTTP proxy is being used and the proxy refuses the

+	 *             connection, then a {@link HTTPProxyException} may be thrown,

+	 *             which contains the details returned by the proxy. If the

+	 *             proxy is buggy and does not return a proper HTTP response,

+	 *             then a normal IOException is thrown instead.

 	 */

 	public synchronized ConnectionInfo connect(ServerHostKeyVerifier verifier, int connectTimeout, int kexTimeout)

 			throws IOException

@@ -649,16 +683,17 @@ public class Connection
 

 		tm.setConnectionMonitors(connectionMonitors);

 

-		/* Make sure that the runnable below will observe the new value of "tm"

-		 * and "state" (the runnable will be executed in a different thread, which

-		 * may be already running, that is why we need a memory barrier here).

-		 * See also the comment in Channel.java if you

-		 * are interested in the details.

+		/*

+		 * Make sure that the runnable below will observe the new value of "tm"

+		 * and "state" (the runnable will be executed in a different thread,

+		 * which may be already running, that is why we need a memory barrier

+		 * here). See also the comment in Channel.java if you are interested in

+		 * the details.

 		 * 

-		 * OKOK, this is paranoid since adding the runnable to the todo list

-		 * of the TimeoutService will ensure that all writes have been flushed

-		 * before the Runnable reads anything

-		 * (there is a synchronized block in TimeoutService.addTimeoutHandler).

+		 * OKOK, this is paranoid since adding the runnable to the todo list of

+		 * the TimeoutService will ensure that all writes have been flushed

+		 * before the Runnable reads anything (there is a synchronized block in

+		 * TimeoutService.addTimeoutHandler).

 		 */

 

 		synchronized (tm)

@@ -719,9 +754,10 @@ public class Connection
 				{

 					if (state.timeoutSocketClosed)

 						throw new IOException("This exception will be replaced by the one below =)");

-					/* Just in case the "cancelTimeoutHandler" invocation came just a little bit

-					 * too late but the handler did not enter the semaphore yet - we can

-					 * still stop it.

+					/*

+					 * Just in case the "cancelTimeoutHandler" invocation came

+					 * just a little bit too late but the handler did not enter

+					 * the semaphore yet - we can still stop it.

 					 */

 					state.isCancelled = true;

 				}

@@ -740,7 +776,10 @@ public class Connection
 

 			synchronized (state)

 			{

-				/* Show a clean exception, not something like "the socket is closed!?!" */

+				/*

+				 * Show a clean exception, not something like "the socket is

+				 * closed!?!"

+				 */

 				if (state.timeoutSocketClosed)

 					throw new SocketTimeoutException("The kexTimeout (" + kexTimeout + " ms) expired.");

 			}

@@ -755,17 +794,21 @@ public class Connection
 	}

 

 	/**

-	 * Creates a new {@link LocalPortForwarder}.

-	 * A <code>LocalPortForwarder</code> forwards TCP/IP connections that arrive at a local

-	 * port via the secure tunnel to another host (which may or may not be

-	 * identical to the remote SSH-2 server).

+	 * Creates a new {@link LocalPortForwarder}. A

+	 * <code>LocalPortForwarder</code> forwards TCP/IP connections that arrive

+	 * at a local port via the secure tunnel to another host (which may or may

+	 * not be identical to the remote SSH-2 server).

 	 * <p>

-	 * This method must only be called after one has passed successfully the authentication step.

-	 * There is no limit on the number of concurrent forwardings.

+	 * This method must only be called after one has passed successfully the

+	 * authentication step. There is no limit on the number of concurrent

+	 * forwardings.

 	 * 

-	 * @param local_port the local port the LocalPortForwarder shall bind to.

-	 * @param host_to_connect target address (IP or hostname)

-	 * @param port_to_connect target port

+	 * @param local_port

+	 *            the local port the LocalPortForwarder shall bind to.

+	 * @param host_to_connect

+	 *            target address (IP or hostname)

+	 * @param port_to_connect

+	 *            target port

 	 * @return A {@link LocalPortForwarder} object.

 	 * @throws IOException

 	 */

@@ -782,17 +825,22 @@ public class Connection
 	}

 

 	/**

-	 * Creates a new {@link LocalPortForwarder}.

-	 * A <code>LocalPortForwarder</code> forwards TCP/IP connections that arrive at a local

-	 * port via the secure tunnel to another host (which may or may not be

-	 * identical to the remote SSH-2 server).

+	 * Creates a new {@link LocalPortForwarder}. A

+	 * <code>LocalPortForwarder</code> forwards TCP/IP connections that arrive

+	 * at a local port via the secure tunnel to another host (which may or may

+	 * not be identical to the remote SSH-2 server).

 	 * <p>

-	 * This method must only be called after one has passed successfully the authentication step.

-	 * There is no limit on the number of concurrent forwardings.

+	 * This method must only be called after one has passed successfully the

+	 * authentication step. There is no limit on the number of concurrent

+	 * forwardings.

 	 * 

-	 * @param addr specifies the InetSocketAddress where the local socket shall be bound to.

-	 * @param host_to_connect target address (IP or hostname)

-	 * @param port_to_connect target port

+	 * @param addr

+	 *            specifies the InetSocketAddress where the local socket shall

+	 *            be bound to.

+	 * @param host_to_connect

+	 *            target address (IP or hostname)

+	 * @param port_to_connect

+	 *            target port

 	 * @return A {@link LocalPortForwarder} object.

 	 * @throws IOException

 	 */

@@ -809,10 +857,11 @@ public class Connection
 	}

 

 	/**

-	 * Creates a new {@link LocalStreamForwarder}.

-	 * A <code>LocalStreamForwarder</code> manages an Input/Outputstream pair

-	 * that is being forwarded via the secure tunnel into a TCP/IP connection to another host

-	 * (which may or may not be identical to the remote SSH-2 server).

+	 * Creates a new {@link LocalStreamForwarder}. A

+	 * <code>LocalStreamForwarder</code> manages an Input/Outputstream pair

+	 * that is being forwarded via the secure tunnel into a TCP/IP connection to

+	 * another host (which may or may not be identical to the remote SSH-2

+	 * server).

 	 * 

 	 * @param host_to_connect

 	 * @param port_to_connect

@@ -832,8 +881,8 @@ public class Connection
 	}

 

 	/**

-	 * Create a very basic {@link SCPClient} that can be used to copy

-	 * files from/to the SSH-2 server.

+	 * Create a very basic {@link SCPClient} that can be used to copy files

+	 * from/to the SSH-2 server.

 	 * <p>

 	 * Works only after one has passed successfully the authentication step.

 	 * There is no limit on the number of concurrent SCP clients.

@@ -861,8 +910,8 @@ public class Connection
 	 * the only effect that the so far specified parameters will be used for the

 	 * next (server driven) key exchange.

 	 * <p>

-	 * Note: This implementation will never start a key exchange (other than the initial one)

-	 * unless you or the SSH-2 server ask for it.

+	 * Note: This implementation will never start a key exchange (other than the

+	 * initial one) unless you or the SSH-2 server ask for it.

 	 * 

 	 * @throws IOException

 	 *             In case of any failure behind the scenes.

@@ -896,9 +945,9 @@ public class Connection
 	}

 

 	/**

-	 * Returns a {@link ConnectionInfo} object containing the details of

-	 * the connection. Can be called as soon as the connection has been

-	 * established (successfully connected).

+	 * Returns a {@link ConnectionInfo} object containing the details of the

+	 * connection. Can be called as soon as the connection has been established

+	 * (successfully connected).

 	 * 

 	 * @return A {@link ConnectionInfo} object.

 	 * @throws IOException

@@ -921,8 +970,9 @@ public class Connection
 	 * Note 1: the username will only be used if no authentication step was done

 	 * so far (it will be used to ask the server for a list of possible

 	 * authentication methods by sending the initial "none" request). Otherwise,

-	 * this method ignores the user name and returns a cached method list

-	 * (which is based on the information contained in the last negative server response).

+	 * this method ignores the user name and returns a cached method list (which

+	 * is based on the information contained in the last negative server

+	 * response).

 	 * <p>

 	 * Note 2: the server may return method names that are not supported by this

 	 * implementation.

@@ -971,9 +1021,9 @@ public class Connection
 	/**

 	 * Returns true if there was at least one failed authentication request and

 	 * the last failed authentication request was marked with "partial success"

-	 * by the server. This is only needed in the rare case of SSH-2 server setups

-	 * that cannot be satisfied with a single successful authentication request

-	 * (i.e., multiple authentication steps are needed.)

+	 * by the server. This is only needed in the rare case of SSH-2 server

+	 * setups that cannot be satisfied with a single successful authentication

+	 * request (i.e., multiple authentication steps are needed.)

 	 * <p>

 	 * If you are interested in the details, then have a look at RFC4252.

 	 * 

@@ -1026,9 +1076,9 @@ public class Connection
 	}

 

 	/**

-	 * Open a new {@link Session} on this connection. Works only after one has passed

-	 * successfully the authentication step. There is no limit on the number of

-	 * concurrent sessions.

+	 * Open a new {@link Session} on this connection. Works only after one has

+	 * passed successfully the authentication step. There is no limit on the

+	 * number of concurrent sessions.

 	 * 

 	 * @return A {@link Session} object.

 	 * @throws IOException

@@ -1045,8 +1095,9 @@ public class Connection
 	}

 

 	/**

-	 * Send an SSH_MSG_IGNORE packet. This method will generate a random data attribute

-	 * (length between 0 (invlusive) and 16 (exclusive) bytes, contents are random bytes).

+	 * Send an SSH_MSG_IGNORE packet. This method will generate a random data

+	 * attribute (length between 0 (invlusive) and 16 (exclusive) bytes,

+	 * contents are random bytes).

 	 * <p>

 	 * This method must only be called once the connection is established.

 	 * 

@@ -1085,11 +1136,12 @@ public class Connection
 	}

 

 	/**

-	 * Removes duplicates from a String array, keeps only first occurence

-	 * of each element. Does not destroy order of elements; can handle nulls.

-	 * Uses a very efficient O(N^2) algorithm =)

+	 * Removes duplicates from a String array, keeps only first occurence of

+	 * each element. Does not destroy order of elements; can handle nulls. Uses

+	 * a very efficient O(N^2) algorithm =)

 	 * 

-	 * @param list a String array.

+	 * @param list

+	 *            a String array.

 	 * @return a cleaned String array.

 	 */

 	private String[] removeDuplicates(String[] list)

@@ -1164,7 +1216,8 @@ public class Connection
 	 * know what you are doing, you will never need this. Default values are

 	 * defined in the {@link DHGexParameters} class.

 	 * 

-	 * @param dgp {@link DHGexParameters}, non null.

+	 * @param dgp

+	 *            {@link DHGexParameters}, non null.

 	 * 

 	 */

 	public synchronized void setDHGexParameters(DHGexParameters dgp)

@@ -1205,16 +1258,17 @@ public class Connection
 	}

 

 	/**

-	 * Define the set of allowed server host key algorithms to be used for

-	 * the following key exchange operations.

+	 * Define the set of allowed server host key algorithms to be used for the

+	 * following key exchange operations.

 	 * <p>

 	 * Unless you know what you are doing, you will never need this.

 	 * 

-	 * @param algos An array of allowed server host key algorithms.

-	 * 	SSH-2 defines <code>ssh-dss</code> and <code>ssh-rsa</code>.

-	 * 	The entries of the array must be ordered after preference, i.e.,

-	 *  the entry at index 0 is the most preferred one. You must specify

-	 *  at least one entry.

+	 * @param algos

+	 *            An array of allowed server host key algorithms. SSH-2 defines

+	 *            <code>ssh-dss</code> and <code>ssh-rsa</code>. The

+	 *            entries of the array must be ordered after preference, i.e.,

+	 *            the entry at index 0 is the most preferred one. You must

+	 *            specify at least one entry.

 	 */

 	public synchronized void setServerHostKeyAlgorithms(String[] algos)

 	{

@@ -1227,13 +1281,16 @@ public class Connection
 	}

 

 	/**

-	 * Enable/disable TCP_NODELAY (disable/enable Nagle's algorithm) on the underlying socket.

+	 * Enable/disable TCP_NODELAY (disable/enable Nagle's algorithm) on the

+	 * underlying socket.

 	 * <p>

 	 * Can be called at any time. If the connection has not yet been established

-	 * then the passed value will be stored and set after the socket has been set up.

-	 * The default value that will be used is <code>false</code>.

+	 * then the passed value will be stored and set after the socket has been

+	 * set up. The default value that will be used is <code>false</code>.

 	 * 

-	 * @param enable the argument passed to the <code>Socket.setTCPNoDelay()</code> method.

+	 * @param enable

+	 *            the argument passed to the <code>Socket.setTCPNoDelay()</code>

+	 *            method.

 	 * @throws IOException

 	 */

 	public synchronized void setTCPNoDelay(boolean enable) throws IOException

@@ -1245,19 +1302,22 @@ public class Connection
 	}

 

 	/**

-	 * Used to tell the library that the connection shall be established through a proxy server.

-	 * It only makes sense to call this method before calling the {@link #connect() connect()}

-	 * method.

+	 * Used to tell the library that the connection shall be established through

+	 * a proxy server. It only makes sense to call this method before calling

+	 * the {@link #connect() connect()} method.

 	 * <p>

 	 * At the moment, only HTTP proxies are supported.

 	 * <p>

-	 * Note: This method can be called any number of times. The {@link #connect() connect()}

-	 * method will use the value set in the last preceding invocation of this method.

+	 * Note: This method can be called any number of times. The

+	 * {@link #connect() connect()} method will use the value set in the last

+	 * preceding invocation of this method.

 	 * 

 	 * @see HTTPProxyData

 	 * 

-	 * @param proxyData Connection information about the proxy. If <code>null</code>, then

-	 *                  no proxy will be used (non surprisingly, this is also the default).

+	 * @param proxyData

+	 *            Connection information about the proxy. If <code>null</code>,

+	 *            then no proxy will be used (non surprisingly, this is also the

+	 *            default).

 	 */

 	public synchronized void setProxyData(ProxyData proxyData)

 	{

@@ -1265,40 +1325,47 @@ public class Connection
 	}

 

 	/**

-	 * Request a remote port forwarding.

-	 * If successful, then forwarded connections will be redirected to the given target address.

-	 * You can cancle a requested remote port forwarding by calling

+	 * Request a remote port forwarding. If successful, then forwarded

+	 * connections will be redirected to the given target address. You can

+	 * cancle a requested remote port forwarding by calling

 	 * {@link #cancelRemotePortForwarding(int) cancelRemotePortForwarding()}.

 	 * <p>

-	 * A call of this method will block until the peer either agreed or disagreed to your request-

+	 * A call of this method will block until the peer either agreed or

+	 * disagreed to your request-

 	 * <p>

 	 * Note 1: this method typically fails if you

 	 * <ul>

-	 * <li>pass a port number for which the used remote user has not enough permissions (i.e., port

-	 * &lt; 1024)</li>

+	 * <li>pass a port number for which the used remote user has not enough

+	 * permissions (i.e., port &lt; 1024)</li>

 	 * <li>or pass a port number that is already in use on the remote server</li>

 	 * <li>or if remote port forwarding is disabled on the server.</li>

 	 * </ul>

 	 * <p>

-	 * Note 2: (from the openssh man page): By default, the listening socket on the server will be

-	 * bound to the loopback interface only. This may be overriden by specifying a bind address.

-	 * Specifying a remote bind address will only succeed if the server's <b>GatewayPorts</b> option

-	 * is enabled (see sshd_config(5)).

+	 * Note 2: (from the openssh man page): By default, the listening socket on

+	 * the server will be bound to the loopback interface only. This may be

+	 * overriden by specifying a bind address. Specifying a remote bind address

+	 * will only succeed if the server's <b>GatewayPorts</b> option is enabled

+	 * (see sshd_config(5)).

 	 * 

-	 * @param bindAddress address to bind to on the server:

-	 *                    <ul>

-	 *                    <li>"" means that connections are to be accepted on all protocol families

-	 *                    supported by the SSH implementation</li>

-	 *                    <li>"0.0.0.0" means to listen on all IPv4 addresses</li>

-	 *                    <li>"::" means to listen on all IPv6 addresses</li>

-	 *                    <li>"localhost" means to listen on all protocol families supported by the SSH

-	 *                    implementation on loopback addresses only, [RFC3330] and RFC3513]</li>

-	 *                    <li>"127.0.0.1" and "::1" indicate listening on the loopback interfaces for

-	 *                    IPv4 and IPv6 respectively</li>

-	 *                    </ul>

-	 * @param bindPort port number to bind on the server (must be &gt; 0)

-	 * @param targetAddress the target address (IP or hostname)

-	 * @param targetPort the target port

+	 * @param bindAddress

+	 *            address to bind to on the server:

+	 *            <ul>

+	 *            <li>"" means that connections are to be accepted on all

+	 *            protocol families supported by the SSH implementation</li>

+	 *            <li>"0.0.0.0" means to listen on all IPv4 addresses</li>

+	 *            <li>"::" means to listen on all IPv6 addresses</li>

+	 *            <li>"localhost" means to listen on all protocol families

+	 *            supported by the SSH implementation on loopback addresses

+	 *            only, [RFC3330] and RFC3513]</li>

+	 *            <li>"127.0.0.1" and "::1" indicate listening on the loopback

+	 *            interfaces for IPv4 and IPv6 respectively</li>

+	 *            </ul>

+	 * @param bindPort

+	 *            port number to bind on the server (must be &gt; 0)

+	 * @param targetAddress

+	 *            the target address (IP or hostname)

+	 * @param targetPort

+	 *            the target port

 	 * @throws IOException

 	 */

 	public synchronized void requestRemotePortForwarding(String bindAddress, int bindPort, String targetAddress,

@@ -1317,14 +1384,17 @@ public class Connection
 	}

 

 	/**

-	 * Cancel an earlier requested remote port forwarding. 

-	 * Currently active forwardings will not be affected (e.g., disrupted).

-	 * Note that further connection forwarding requests may be received until

-	 * this method has returned.

+	 * Cancel an earlier requested remote port forwarding. Currently active

+	 * forwardings will not be affected (e.g., disrupted). Note that further

+	 * connection forwarding requests may be received until this method has

+	 * returned.

 	 * 

-	 * @param bindPort the allocated port number on the server

-	 * @throws IOException if the remote side refuses the cancel request or another low

-	 *         level error occurs (e.g., the underlying connection is closed)

+	 * @param bindPort

+	 *            the allocated port number on the server

+	 * @throws IOException

+	 *             if the remote side refuses the cancel request or another low

+	 *             level error occurs (e.g., the underlying connection is

+	 *             closed)

 	 */

 	public synchronized void cancelRemotePortForwarding(int bindPort) throws IOException

 	{

@@ -1338,13 +1408,14 @@ public class Connection
 	}

 

 	/**

-	 * Provide your own instance of SecureRandom. Can be used, e.g., if you

-	 * want to seed the used SecureRandom generator manually.

+	 * Provide your own instance of SecureRandom. Can be used, e.g., if you want

+	 * to seed the used SecureRandom generator manually.

 	 * <p>

-	 * The SecureRandom instance is used during key exchanges, public key authentication,

-	 * x11 cookie generation and the like.

+	 * The SecureRandom instance is used during key exchanges, public key

+	 * authentication, x11 cookie generation and the like.

 	 * 

-	 * @param rnd a SecureRandom instance

+	 * @param rnd

+	 *            a SecureRandom instance

 	 */

 	public synchronized void setSecureRandom(SecureRandom rnd)

 	{

@@ -1353,4 +1424,75 @@ public class Connection
 

 		this.generator = rnd;

 	}

+

+	/**

+	 * Enable/disable debug logging. <b>Only do this when requested by Trilead

+	 * support.</b>

+	 * <p>

+	 * For speed reasons, some static variables used to check whether debugging

+	 * is enabled are not protected with locks. In other words, if you

+	 * dynamicaly enable/disable debug logging, then some threads may still use

+	 * the old setting. To be on the safe side, enable debugging before doing

+	 * the <code>connect()</code> call.

+	 * 

+	 * @param enable

+	 *            on/off

+	 * @param logger

+	 *            a {@link DebugLogger DebugLogger} instance, <code>null</code>

+	 *            means logging using the simple logger which logs all messages

+	 *            to to stderr. Ignored if enabled is <code>false</code>

+	 */

+	public synchronized void enableDebugging(boolean enable, DebugLogger logger)

+	{

+		Logger.enabled = enable;

+

+		if (enable == false)

+		{

+			Logger.logger = null;

+		}

+		else

+		{

+			if (logger == null)

+			{

+				logger = new DebugLogger()

+				{

+

+					public void log(int level, String className, String message)

+					{

+						long now = System.currentTimeMillis();

+						System.err.println(now + " : " + className + ": " + message);

+					}

+				};

+			}

+		}

+	}

+

+	/**

+	 * This method can be used to perform end-to-end connection testing. It

+	 * sends a 'ping' message to the server and waits for the 'pong' from the

+	 * server.

+	 * <p>

+	 * When this method throws an exception, then you can assume that the

+	 * connection should be abandoned.

+	 * <p>

+	 * Note: Works only after one has passed successfully the authentication

+	 * step.

+	 * <p>

+	 * Implementation details: this method sends a SSH_MSG_GLOBAL_REQUEST

+	 * request ('trilead-ping') to the server and waits for the

+	 * SSH_MSG_REQUEST_FAILURE reply packet from the server.

+	 * 

+	 * @throws IOException

+	 *             in case of any problem

+	 */

+	public synchronized void ping() throws IOException

+	{

+		if (tm == null)

+			throw new IllegalStateException("You need to establish a connection first.");

+

+		if (!authenticated)

+			throw new IllegalStateException("The connection is not authenticated.");

+

+		cm.requestGlobalTrileadPing();

+	}

 }