Fix missing Javadoc

Add Javadoc to classes that were missing it to pass the checkstyle validation.

Author: kruton

config/checkstyle/checkstyle.xml

@@ -23,6 +23,10 @@
 		<module name="WhitespaceAround">
 			<property name="allowEmptyMethods" value="true" />
 		</module>
+		<!-- Javadoc checks for public classes only -->
+		<module name="JavadocType">
+			<property name="scope" value="public" />
+		</module>
 		<!-- No trailing whitespace -->
 		<module name="Regexp">
 			<property name="format" value="[ \t]+$" />

config/checkstyle/suppressions.xml

@@ -43,4 +43,7 @@
 		checks="RegexpSinglelineJavaCheck" />
 	<suppress files="sshlib/src/main/java/de/mud/.+\.java"
 		checks=".*" />
+	<!-- Test files don't need Javadoc -->
+	<suppress files="sshlib/src/test/java/.+\.java"
+		checks="JavadocType" />
 </suppressions>

src/main/java/com/trilead/ssh2/SCPClient.java

@@ -18,9 +18,23 @@
  * This scp client is thread safe - you can download (and upload) different sets
  * of files concurrently without any troubles. The <code>SCPClient</code> is
  * actually mapping every request to a distinct {@link Session}.
+ * <p>
+ * Basic example - copy a file to the remote server:
+ * <pre>{@code
+ * Connection conn = new Connection("hostname");
+ * conn.connect();
+ * conn.authenticateWithPassword("username", "password");
+ *
+ * SCPClient scp = new SCPClient(conn);
+ * scp.put("local.txt", "/remote/path/");
+ *
+ * conn.close();
+ * }</pre>
  *
  * @author Christian Plattner, plattner@trilead.com
  * @version $Id: SCPClient.java,v 1.2 2008/04/01 12:38:09 cplattne Exp $
+ * @see Connection
+ * @see Session
  */
 
 public class SCPClient

src/main/java/com/trilead/ssh2/SFTPv3Client.java

@@ -28,11 +28,28 @@
  * Note: this is experimental code.
  * <p>
  * Error handling: the methods of this class throw IOExceptions. However, unless
- * there is catastrophic failure, exceptions of the type {@link SFTPv3Client} will
+ * there is catastrophic failure, exceptions of the type {@link SFTPException} will
  * be thrown (a subclass of IOException). Therefore, you can implement more verbose
  * behavior by checking if a thrown exception if of this type. If yes, then you
  * can cast the exception and access detailed information about the failure.
  * <p>
+ * Basic example - upload a file:
+ * <pre>{@code
+ * Connection conn = new Connection("hostname");
+ * conn.connect();
+ * conn.authenticateWithPassword("username", "password");
+ *
+ * SFTPv3Client sftp = new SFTPv3Client(conn);
+ *
+ * SFTPv3FileHandle handle = sftp.createFile("remote.txt");
+ * byte[] data = "Hello, SFTP!".getBytes();
+ * sftp.write(handle, 0, data, 0, data.length);
+ * sftp.closeFile(handle);
+ *
+ * sftp.close();
+ * conn.close();
+ * }</pre>
+ * <p>
  * Notes about file names, directory names and paths, copy-pasted
  * from the specs:
  * <ul>
@@ -57,6 +74,8 @@
  *
  * @author Christian Plattner, plattner@trilead.com
  * @version $Id: SFTPv3Client.java,v 1.3 2008/04/01 12:38:09 cplattne Exp $
+ * @see Connection
+ * @see SFTPException
  */
 public class SFTPv3Client
 {

src/main/java/com/trilead/ssh2/Session.java

@@ -16,9 +16,30 @@
  * in this context either a shell, an application or a system command. The
  * program may or may not have a tty. Only one single program can be started on
  * a session. However, multiple sessions can be active simultaneously.
+ * <p>
+ * Basic example - execute a command and read output:
+ * <pre>{@code
+ * Connection conn = new Connection("hostname");
+ * conn.connect();
+ * conn.authenticateWithPassword("username", "password");
+ *
+ * Session sess = conn.openSession();
+ * sess.execCommand("uname -a");
+ *
+ * InputStream stdout = sess.getStdout();
+ * BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
+ * while (true) {
+ *     String line = br.readLine();
+ *     if (line == null) break;
+ *     System.out.println(line);
+ * }
+ * sess.close();
+ * conn.close();
+ * }</pre>
  *
  * @author Christian Plattner, plattner@trilead.com
  * @version $Id: Session.java,v 1.2 2008/03/03 07:01:36 cplattne Exp $
+ * @see Connection#openSession()
  */
 public class Session implements AutoCloseable
 {

src/main/java/com/trilead/ssh2/auth/SignatureProxy.java

@@ -7,6 +7,14 @@
 import java.io.IOException;
 import java.security.PublicKey;
 
+/**
+ * Proxy for signing operations using external private keys.
+ * <p>
+ * Enables SSH authentication with keys stored in external systems
+ * (hardware tokens, key managers) by delegating the signing operation.
+ *
+ * @see AuthenticationManager
+ */
 public abstract class SignatureProxy
 {
 	public static final String SHA1 = "SHA-1";

src/main/java/com/trilead/ssh2/channel/ChannelManager.java

@@ -30,12 +30,33 @@
 import com.trilead.ssh2.transport.MessageHandler;
 
 /**
- * ChannelManager. Please read the comments in Channel.java.
+ * ChannelManager coordinates all SSH channels over a single transport connection.
  * <p>
- * Besides the crypto part, this is the core of the library.
+ * This class is the core of the SSH channel layer, managing:
+ * <ul>
+ * <li>Channel lifecycle (open, close, EOF)</li>
+ * <li>Data transmission and flow control</li>
+ * <li>Channel requests (PTY, X11, exec, shell, subsystem)</li>
+ * <li>Global requests (port forwarding, ping)</li>
+ * <li>SSH message routing to appropriate channel handlers</li>
+ * </ul>
+ * <p>
+ * Architecture: ChannelManager implements {@link MessageHandler} to receive
+ * SSH packets in the range 80-100 (channel-related messages) from the
+ * {@link com.trilead.ssh2.transport.TransportManager}. It maintains a registry
+ * of active channels and routes messages to the appropriate channel instance.
+ * <p>
+ * The manager handles both synchronous operations (like opening a session channel)
+ * and asynchronous message processing (incoming data, window adjustments, channel close).
+ * <p>
+ * Thread safety: All channel operations are synchronized on the channels list or
+ * individual channel objects to ensure proper concurrency control.
  *
  * @author Christian Plattner, plattner@trilead.com
  * @version $Id: ChannelManager.java,v 1.2 2008/03/03 07:01:36 cplattne Exp $
+ * @see Channel
+ * @see MessageHandler
+ * @see com.trilead.ssh2.transport.ITransportConnection
  */
 public class ChannelManager implements MessageHandler
 {

src/main/java/com/trilead/ssh2/crypto/cipher/AES.java

@@ -44,6 +44,9 @@ public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff) {
 		}
 	}
 
+	/**
+	 * AES in CBC (Cipher Block Chaining) mode for SSH.
+	 */
 	public static class CBC extends AES {
 		public CBC() throws IllegalArgumentException {
 			try {
@@ -54,6 +57,9 @@ public CBC() throws IllegalArgumentException {
 		}
 	}
 
+	/**
+	 * AES in CTR (Counter) mode for SSH.
+	 */
 	public static class CTR extends AES {
 		public CTR() throws IllegalArgumentException {
 			try {

src/main/java/com/trilead/ssh2/crypto/cipher/BlowFish.java

@@ -415,6 +415,9 @@ public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff) {
 		}
 	}
 
+	/**
+	 * BlowFish in CBC mode.
+	 */
 	public static class CBC extends Wrapper {
 		@Override
 		public void init(boolean forEncryption, byte[] key, byte[] iv) throws IllegalArgumentException {
@@ -424,6 +427,9 @@ public void init(boolean forEncryption, byte[] key, byte[] iv) throws IllegalArg
 		}
 	}
 
+	/**
+	 * BlowFish in CTR mode.
+	 */
 	public static class CTR extends Wrapper {
 		@Override
 		public void init(boolean forEncryption, byte[] key, byte[] iv) throws IllegalArgumentException {

src/main/java/com/trilead/ssh2/crypto/cipher/DES.java

@@ -28,11 +28,10 @@
  */
 
 /**
- * DES.
+ * A class that provides a basic DES engine.
  *
  * @author See comments in the source file
  * @version $Id: DES.java,v 1.1 2007/10/15 12:49:55 cplattne Exp $
- *
  */
 public class DES implements BlockCipher
 {
@@ -369,6 +368,9 @@ protected void desFunc(int[] wKey, byte[] in, int inOff, byte[] out, int outOff)
 		out[outOff + 7] = (byte) (left & 0xff);
 	}
 
+	/**
+	 * DES in CBC mode.
+	 */
 	public static class CBC implements BlockCipher {
 		protected BlockCipher bc;