[maven-release-plugin] prepare release v0.3.1

* added a TransferListener for monitoring file transfer

NOTICE

@@ -6,3 +6,60 @@ The Apache Software Foundation (http://www.apache.org/):
 
 - Apache MINA SSHD
 - Apache Commons-Net
+
+
+// Apache Mina SSHD notice
+
+   =========================================================================
+   ==  NOTICE file for use with the Apache License, Version 2.0,          ==
+   ==  in this case for the SSHD distribution.                            ==
+   =========================================================================
+
+   This product contains software developped by JCraft,Inc. and subject to
+   the following license:
+
+Copyright (c) 2002,2003,2004,2005,2006,2007,2008 Atsuhiko Yamanaka, JCraft,Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in
+     the documentation and/or other materials provided with the distribution.
+
+  3. The names of the authors may not be used to endorse or promote products
+     derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
+INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
+INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+--------------------------------------------------------------------------------
+Copyright (c) 2000 - 2006 The Legion Of The Bouncy Castle (http://www.bouncycastle.org)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in the
+Software without restriction, including without limitation the rights to use, copy,
+modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+and to permit persons to whom the Software is furnished to do so, subject to the
+following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.rst

@@ -1,3 +1,8 @@
+.. image:: http://api.flattr.com/button/button-compact-static-100x17.png
+    :align: right
+    :alt: Flattr this
+    :target: http://flattr.com/thing/49085/sshj-ssh-scp-and-sftp-library-for-java
+
 sshj - SSHv2 library for Java
 ==============================
 
@@ -6,10 +11,10 @@ To get started, have a look at one of the examples. Hopefully you will find the
 Features of the library include:
 
 * reading known_hosts files for host key verification
-* password and publickey authentication
+* publickey, password and keyboard-interactive authentication
 * command, subsystem and shell channels
 * local and remote port forwarding
-* scp + complete sftp version 3 implementation
+* scp + complete sftp version 0-3 implementation
 
 Implementations of the following algorithms are included:
 
@@ -37,8 +42,7 @@ If you need something that is not implemented, it shouldn't be too hard to add (
 Dependencies
 -------------
 
-slf4j_ is required. bouncycastle_ is highly recommended and required for using some of the crypto algorithms.
-jzlib_ is required for using zlib compression.
+Java 6+. slf4j_ is required. bouncycastle_ is highly recommended and required for using some of the crypto algorithms. jzlib_ is required for using zlib compression.
 
 
 Help and discussion
@@ -53,8 +57,6 @@ Contributing
 Fork away!
 
 
-.. _buildr: http://buildr.apache.org/installing.html
-
 .. _slf4j: http://www.slf4j.org/download.html
 
 .. _bouncycastle: http://www.bouncycastle.org/java.html

pom.xml

@@ -6,7 +6,7 @@
     <groupId>net.schmizz</groupId>
     <artifactId>sshj</artifactId>
     <packaging>jar</packaging>
-    <version>0.1.1</version>
+    <version>0.3.1</version>
 
     <name>sshj</name>
     <description>SSHv2 library for Java</description>
@@ -37,65 +37,43 @@
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
-            <version>1.5.11</version>
+            <version>1.6.1</version>
         </dependency>
         <dependency>
             <groupId>org.bouncycastle</groupId>
-            <artifactId>bcprov-jdk15</artifactId>
+            <artifactId>bcprov-jdk16</artifactId>
             <version>1.45</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.8.1</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.jcraft</groupId>
             <artifactId>jzlib</artifactId>
             <version>1.0.7</version>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>4.6</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.apache.sshd</groupId>
             <artifactId>sshd-core</artifactId>
-            <version>0.3.0</version>
+            <version>0.4.0</version>
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-log4j12</artifactId>
-            <version>1.5.11</version>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-core</artifactId>
+            <version>0.9.24</version>
             <scope>test</scope>
         </dependency>
         <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>1.2.15</version>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>0.9.24</version>
             <scope>test</scope>
-            <exclusions>
-                <exclusion>
-                    <groupId>com.sun.jdmk</groupId>
-                    <artifactId>jmxtools</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>com.sun.jmx</groupId>
-                    <artifactId>jmxri</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>javax.jms</groupId>
-                    <artifactId>jms</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>javax.mail</groupId>
-                    <artifactId>mail</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>oro</groupId>
-                    <artifactId>oro</artifactId>
-                </exclusion>
-            </exclusions>
         </dependency>
     </dependencies>
 
@@ -109,6 +87,10 @@
         </developer>
     </developers>
 
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
     <build>
         <plugins>
             <plugin>
@@ -118,8 +100,8 @@
                     <excludes>
                         <exclude>examples/*.java</exclude>
                     </excludes>
-                    <source>1.5</source>
-                    <target>1.5</target>
+                    <source>1.6</source>
+                    <target>1.6</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -127,6 +109,24 @@
                 <artifactId>maven-release-plugin</artifactId>
                 <version>2.0</version>
             </plugin>
+            <plugin>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>2.2-beta-5</version>
+                <configuration>
+                    <descriptors>
+                        <descriptor>src/assemble/examples.xml</descriptor>
+                    </descriptors>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
@@ -172,11 +172,11 @@
 
     <profiles>
         <profile>
-            <id>dev</id>
+            <id>full-deps</id>
             <dependencies>
                 <dependency>
                     <groupId>org.bouncycastle</groupId>
-                    <artifactId>bcprov-jdk15</artifactId>
+                    <artifactId>bcprov-jdk16</artifactId>
                     <version>1.45</version>
                 </dependency>
                 <dependency>
@@ -185,36 +185,14 @@
                     <version>1.0.7</version>
                 </dependency>
                 <dependency>
-                    <groupId>org.slf4j</groupId>
-                    <artifactId>slf4j-log4j12</artifactId>
-                    <version>1.5.11</version>
+                    <groupId>ch.qos.logback</groupId>
+                    <artifactId>logback-core</artifactId>
+                    <version>0.9.24</version>
                 </dependency>
                 <dependency>
-                    <groupId>log4j</groupId>
-                    <artifactId>log4j</artifactId>
-                    <version>1.2.15</version>
-                    <exclusions>
-                        <exclusion>
-                            <groupId>com.sun.jdmk</groupId>
-                            <artifactId>jmxtools</artifactId>
-                        </exclusion>
-                        <exclusion>
-                            <groupId>com.sun.jmx</groupId>
-                            <artifactId>jmxri</artifactId>
-                        </exclusion>
-                        <exclusion>
-                            <groupId>javax.jms</groupId>
-                            <artifactId>jms</artifactId>
-                        </exclusion>
-                        <exclusion>
-                            <groupId>javax.mail</groupId>
-                            <artifactId>mail</artifactId>
-                        </exclusion>
-                        <exclusion>
-                            <groupId>oro</groupId>
-                            <artifactId>oro</artifactId>
-                        </exclusion>
-                    </exclusions>
+                    <groupId>ch.qos.logback</groupId>
+                    <artifactId>logback-classic</artifactId>
+                    <version>0.9.24</version>
                 </dependency>
             </dependencies>
         </profile>

src/assemble/examples.xml

@@ -0,0 +1,15 @@
+<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
+          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0 http://maven.apache.org/xsd/assembly-1.1.0.xsd">
+    <id>examples</id>
+    <formats>
+        <format>zip</format>
+    </formats>
+    <fileSets>
+        <fileSet>
+            <directory>src/main/java/examples</directory>
+            <includes/>
+            <outputDirectory>examples</outputDirectory>
+        </fileSet>
+    </fileSets>
+</assembly>

src/main/java/examples/Exec.java

@@ -16,32 +16,32 @@
 package examples;
 
 import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.connection.channel.direct.Session;
 import net.schmizz.sshj.connection.channel.direct.Session.Command;
 
 import java.io.IOException;
+import java.util.concurrent.TimeUnit;
 
 /** This examples demonstrates how a remote command can be executed. */
 public class Exec {
 
-    // static {
-    // BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-    // }
-
     public static void main(String... args)
             throws IOException {
-        SSHClient ssh = new SSHClient();
+        final SSHClient ssh = new SSHClient();
         ssh.loadKnownHosts();
 
         ssh.connect("localhost");
         try {
-
             ssh.authPublickey(System.getProperty("user.name"));
-
-            Command cmd = ssh.startSession().exec("ping google.com -n 1");
-
-            // Pipe.pipe(cmd.getInputStream(), System.out, cmd.getLocalMaxPacketSize(), false);
-            System.out.print(cmd.getOutputAsString());
-            System.out.println("\n** exit status: " + cmd.getExitStatus());
+            final Session session = ssh.startSession();
+            try {
+                final Command cmd = session.exec("ping -c 1 google.com");
+                System.out.print(cmd.getOutputAsString());
+                cmd.join(5, TimeUnit.SECONDS);
+                System.out.println("\n** exit status: " + cmd.getExitStatus());
+            } finally {
+                session.close();
+            }
 
         } finally {
             ssh.disconnect();

src/main/java/examples/LocalPF.java

@@ -26,11 +26,6 @@ import java.net.InetSocketAddress;
  */
 public class LocalPF {
 
-    // static
-    // {
-    // BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-    // }
-
     public static void main(String... args)
             throws IOException {
         SSHClient ssh = new SSHClient();
@@ -46,7 +41,6 @@ public class LocalPF {
             * _We_ listen on localhost:8080 and forward all connections on to server, which then forwards it to
             * google.com:80
             */
-
             ssh.newLocalPortForwarder(new InetSocketAddress("localhost", 8080), "google.com", 80)
                     .listen();
 

src/main/java/examples/RemotePF.java

@@ -28,10 +28,6 @@ import java.net.InetSocketAddress;
  */
 public class RemotePF {
 
-//    static {
-//        BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-//    }
-
     public static void main(String... args)
             throws IOException {
         SSHClient client = new SSHClient();

src/main/java/examples/RudimentaryPTY.java

@@ -28,10 +28,6 @@ import java.io.IOException;
 /** A very rudimentary psuedo-terminal based on console I/O. */
 class RudimentaryPTY {
 
-//    static {
-//        BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-//    }
-
     public static void main(String... args)
             throws IOException {
 
@@ -41,36 +37,35 @@ class RudimentaryPTY {
         ssh.addHostKeyVerifier(new ConsoleKnownHostsVerifier(khFile, System.console()));
 
         ssh.connect("localhost");
-
-        Shell shell = null;
-
         try {
 
             ssh.authPublickey(System.getProperty("user.name"));
 
             final Session session = ssh.startSession();
-            session.allocateDefaultPTY();
+            try {
 
-            shell = session.startShell();
+                session.allocateDefaultPTY();
 
-            new StreamCopier("stdout", shell.getInputStream(), System.out)
-                    .bufSize(shell.getLocalMaxPacketSize())
-                    .start();
+                final Shell shell = session.startShell();
 
-            new StreamCopier("stderr", shell.getErrorStream(), System.err)
-                    .bufSize(shell.getLocalMaxPacketSize())
-                    .start();
+                new StreamCopier("stdout", shell.getInputStream(), System.out)
+                        .bufSize(shell.getLocalMaxPacketSize())
+                        .start();
 
-            // Now make System.in act as stdin. To exit, hit Ctrl+D (since that results in an EOF on System.in)
-            // This is kinda messy because java only allows console input after you hit return
-            // But this is just an example... a GUI app could implement a proper PTY
-            StreamCopier.copy(System.in, shell.getOutputStream(), shell.getRemoteMaxPacketSize(), true);
+                new StreamCopier("stderr", shell.getErrorStream(), System.err)
+                        .bufSize(shell.getLocalMaxPacketSize())
+                        .start();
+
+                // Now make System.in act as stdin. To exit, hit Ctrl+D (since that results in an EOF on System.in)
+                // This is kinda messy because java only allows console input after you hit return
+                // But this is just an example... a GUI app could implement a proper PTY
+                StreamCopier.copy(System.in, shell.getOutputStream(), shell.getRemoteMaxPacketSize(), true);
+
+            } finally {
+                session.close();
+            }
 
         } finally {
-
-            if (shell != null)
-                shell.close();
-
             ssh.disconnect();
         }
     }

src/main/java/examples/SCPDownload.java

@@ -22,20 +22,17 @@ import java.io.IOException;
 /** This example demonstrates downloading of a file over SCP from the SSH server. */
 public class SCPDownload {
 
-//    static {
-//        BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-//    }
-
     public static void main(String[] args)
             throws IOException {
         SSHClient ssh = new SSHClient();
-        // ssh.useCompression(); // Can lead to significant speedup
+        // ssh.useCompression(); // Can lead to significant speedup (needs JZlib in classpath)
         ssh.loadKnownHosts();
         ssh.connect("localhost");
         try {
             ssh.authPublickey(System.getProperty("user.name"));
-            ssh.newSCPFileTransfer()
-                    .download("well", "/tmp/");
+            final String src = "test_file";
+            final String target = "/tmp/";
+            ssh.newSCPFileTransfer().download(src, target);
         } finally {
             ssh.disconnect();
         }

src/main/java/examples/SCPUpload.java

@@ -17,15 +17,12 @@ package examples;
 
 import net.schmizz.sshj.SSHClient;
 
+import java.io.File;
 import java.io.IOException;
 
 /** This example demonstrates uploading of a file over SCP to the SSH server. */
 public class SCPUpload {
 
-//    static {
-//        BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-//    }
-
     public static void main(String[] args)
             throws IOException, ClassNotFoundException {
         SSHClient ssh = new SSHClient();
@@ -35,10 +32,12 @@ public class SCPUpload {
             ssh.authPublickey(System.getProperty("user.name"));
 
             // Present here to demo algorithm renegotiation - could have just put this before connect()
+            // Make sure JZlib is in classpath for this to work
             ssh.useCompression();
 
-            ssh.newSCPFileTransfer()
-                    .upload("/Users/shikhar/well", "/tmp/");
+            final String src = System.getProperty("user.home") + File.separator + "test_file";
+            final String target = "/tmp/";
+            ssh.newSCPFileTransfer().upload(src, target);
         } finally {
             ssh.disconnect();
         }

src/main/java/examples/SFTPDownload.java

@@ -16,24 +16,28 @@
 package examples;
 
 import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.sftp.SFTPClient;
 
 import java.io.IOException;
 
 /** This example demonstrates downloading of a file over SFTP from the SSH server. */
 public class SFTPDownload {
 
-//    static {
-//        BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-//    }
-
     public static void main(String[] args)
             throws IOException {
-        SSHClient ssh = new SSHClient();
+        final SSHClient ssh = new SSHClient();
         ssh.loadKnownHosts();
         ssh.connect("localhost");
         try {
             ssh.authPublickey(System.getProperty("user.name"));
-            ssh.newSFTPClient().get("well", "/tmp/");
+            final String src = "test_file";
+            final String target = "/tmp/";
+            final SFTPClient sftp = ssh.newSFTPClient();
+            try {
+                sftp.get(src, target);
+            } finally {
+                sftp.close();
+            }
         } finally {
             ssh.disconnect();
         }

src/main/java/examples/SFTPUpload.java

@@ -16,25 +16,29 @@
 package examples;
 
 import net.schmizz.sshj.SSHClient;
+import net.schmizz.sshj.sftp.SFTPClient;
 
+import java.io.File;
 import java.io.IOException;
 
 /** This example demonstrates uploading of a file over SFTP to the SSH server. */
 public class SFTPUpload {
 
-    // static
-    // {
-    // BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-    // }
-
     public static void main(String[] args)
             throws IOException {
-        SSHClient ssh = new SSHClient();
+        final SSHClient ssh = new SSHClient();
         ssh.loadKnownHosts();
         ssh.connect("localhost");
         try {
             ssh.authPublickey(System.getProperty("user.name"));
-            ssh.newSFTPClient().put("/Users/shikhar/well", "/tmp/");
+            final String src = System.getProperty("user.home") + File.separator + "test_file";
+            final String target = "/tmp/";
+            final SFTPClient sftp = ssh.newSFTPClient();
+            try {
+                sftp.put(src, target);
+            } finally {
+                sftp.close();
+            }
         } finally {
             ssh.disconnect();
         }

src/main/java/examples/X11.java

@@ -27,13 +27,9 @@ import java.net.InetSocketAddress;
 /** This example demonstrates how forwarding X11 connections from a remote host can be accomplished. */
 public class X11 {
 
-    // static {
-    // BasicConfigurator.configure(new ConsoleAppender(new PatternLayout("%d [%-15.15t] %-5p %-30.30c{1} - %m%n")));
-    // }
-
     public static void main(String... args)
             throws IOException, InterruptedException {
-        SSHClient ssh = new SSHClient();
+        final SSHClient ssh = new SSHClient();
 
         // Compression makes X11 more feasible over slower connections
         // ssh.useCompression();
@@ -59,7 +55,7 @@ public class X11 {
             */
             sess.reqX11Forwarding("MIT-MAGIC-COOKIE-1", "b0956167c9ad8f34c8a2788878307dc9", 0);
 
-            Command cmd = sess.exec("mate");
+            final Command cmd = sess.exec("/usr/X11/bin/xcalc");
 
             new StreamCopier("stdout", cmd.getInputStream(), System.out).start();
             new StreamCopier("stderr", cmd.getErrorStream(), System.err).start();

src/main/java/net/schmizz/concurrent/Future.java

@@ -32,8 +32,9 @@ import java.util.concurrent.locks.ReentrantLock;
  */
 public class Future<V, T extends Throwable> {
 
-    private final Logger log;
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
+    private final String name;
     private final ExceptionChainer<T> chainer;
     private final ReentrantLock lock;
     private final Condition cond;
@@ -60,7 +61,7 @@ public class Future<V, T extends Throwable> {
      * @param lock    lock to use
      */
     public Future(String name, ExceptionChainer<T> chainer, ReentrantLock lock) {
-        this.log = LoggerFactory.getLogger("<< " + name + " >>");
+        this.name = name;
         this.chainer = chainer;
         this.lock = lock == null ? new ReentrantLock() : lock;
         this.cond = this.lock.newCondition();
@@ -74,7 +75,7 @@ public class Future<V, T extends Throwable> {
     public void set(V val) {
         lock();
         try {
-            log.debug("Setting to `{}`", val);
+            log.debug("Setting <<{}>> to `{}`", name, val);
             this.val = val;
             cond.signalAll();
         } finally {
@@ -139,14 +140,14 @@ public class Future<V, T extends Throwable> {
                 throw pendingEx;
             if (val != null)
                 return val;
-            log.debug("Awaiting");
+            log.debug("Awaiting <<{}>>", name);
             while (val == null && pendingEx == null)
                 if (timeout == 0)
                     cond.await();
                 else if (!cond.await(timeout, unit))
                     throw chainer.chain(new TimeoutException("Timeout expired"));
             if (pendingEx != null) {
-                log.error("Woke to: {}", pendingEx.toString());
+                log.error("<<{}>> woke to: {}", name, pendingEx.toString());
                 throw pendingEx;
             }
             return val;

src/main/java/net/schmizz/sshj/AbstractService.java

@@ -44,29 +44,35 @@ public abstract class AbstractService
         timeout = trans.getTimeout();
     }
 
+    @Override
     public String getName() {
         return name;
     }
 
+    @Override
     public void handle(Message msg, SSHPacket buf)
             throws SSHException {
         trans.sendUnimplemented();
     }
 
+    @Override
     public void notifyError(SSHException error) {
         log.debug("Was notified of {}", error.toString());
     }
 
+    @Override
     public void notifyUnimplemented(long seqNum)
             throws SSHException {
         throw new SSHException(DisconnectReason.PROTOCOL_ERROR, "Unexpected: SSH_MSG_UNIMPLEMENTED");
     }
 
+    @Override
     public void notifyDisconnect()
             throws SSHException {
         log.debug("Was notified of disconnect");
     }
 
+    @Override
     public void request()
             throws TransportException {
         final Service active = trans.getService();

src/main/java/net/schmizz/sshj/AndroidConfig.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010 Shikhar Bhushan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package net.schmizz.sshj;
+
+import net.schmizz.sshj.transport.random.JCERandom;
+import net.schmizz.sshj.transport.random.SingletonRandomFactory;
+
+public class AndroidConfig extends DefaultConfig {
+
+    @Override
+    protected void initRandomFactory(boolean ignored) {
+        setRandomFactory(new SingletonRandomFactory(new JCERandom.Factory()));
+    }
+
+}

src/main/java/net/schmizz/sshj/Config.java

@@ -142,5 +142,5 @@ public interface Config {
      * @param version software version info
      */
     void setVersion(String version);
-    
+
 }

src/main/java/net/schmizz/sshj/ConfigImpl.java

@@ -62,34 +62,42 @@ public class ConfigImpl
     private List<Factory.Named<Signature>> signatureFactories;
     private List<Factory.Named<FileKeyProvider>> fileKeyProviderFactories;
 
+    @Override
     public List<Factory.Named<Cipher>> getCipherFactories() {
         return cipherFactories;
     }
 
+    @Override
     public List<Factory.Named<Compression>> getCompressionFactories() {
         return compressionFactories;
     }
 
+    @Override
     public List<Factory.Named<FileKeyProvider>> getFileKeyProviderFactories() {
         return fileKeyProviderFactories;
     }
 
+    @Override
     public List<Factory.Named<KeyExchange>> getKeyExchangeFactories() {
         return kexFactories;
     }
 
+    @Override
     public List<Factory.Named<MAC>> getMACFactories() {
         return macFactories;
     }
 
+    @Override
     public Factory<Random> getRandomFactory() {
         return randomFactory;
     }
 
+    @Override
     public List<Factory.Named<Signature>> getSignatureFactories() {
         return signatureFactories;
     }
 
+    @Override
     public String getVersion() {
         return version;
     }
@@ -98,6 +106,7 @@ public class ConfigImpl
         setCipherFactories(Arrays.asList(cipherFactories));
     }
 
+    @Override
     public void setCipherFactories(List<Factory.Named<Cipher>> cipherFactories) {
         this.cipherFactories = cipherFactories;
     }
@@ -106,6 +115,7 @@ public class ConfigImpl
         setCompressionFactories(Arrays.asList(compressionFactories));
     }
 
+    @Override
     public void setCompressionFactories(List<Factory.Named<Compression>> compressionFactories) {
         this.compressionFactories = compressionFactories;
     }
@@ -114,6 +124,7 @@ public class ConfigImpl
         setFileKeyProviderFactories(Arrays.asList(fileKeyProviderFactories));
     }
 
+    @Override
     public void setFileKeyProviderFactories(List<Factory.Named<FileKeyProvider>> fileKeyProviderFactories) {
         this.fileKeyProviderFactories = fileKeyProviderFactories;
     }
@@ -122,6 +133,7 @@ public class ConfigImpl
         setKeyExchangeFactories(Arrays.asList(kexFactories));
     }
 
+    @Override
     public void setKeyExchangeFactories(List<Factory.Named<KeyExchange>> kexFactories) {
         this.kexFactories = kexFactories;
     }
@@ -130,10 +142,12 @@ public class ConfigImpl
         setMACFactories(Arrays.asList(macFactories));
     }
 
+    @Override
     public void setMACFactories(List<Factory.Named<MAC>> macFactories) {
         this.macFactories = macFactories;
     }
 
+    @Override
     public void setRandomFactory(Factory<Random> randomFactory) {
         this.randomFactory = randomFactory;
     }
@@ -142,10 +156,12 @@ public class ConfigImpl
         setSignatureFactories(Arrays.asList(signatureFactories));
     }
 
+    @Override
     public void setSignatureFactories(List<Factory.Named<Signature>> signatureFactories) {
         this.signatureFactories = signatureFactories;
     }
 
+    @Override
     public void setVersion(String version) {
         this.version = version;
     }

src/main/java/net/schmizz/sshj/DefaultConfig.java

@@ -91,7 +91,7 @@ public class DefaultConfig
 
     private final Logger log = LoggerFactory.getLogger(getClass());
 
-    private static final String VERSION = "SSHJ_0_1";
+    private static final String VERSION = "SSHJ_0_3";
 
     public DefaultConfig() {
         setVersion(VERSION);
@@ -134,6 +134,7 @@ public class DefaultConfig
                 new TripleDESCBC.Factory(),
                 new BlowfishCBC.Factory()));
 
+        boolean warn = false;
         // Ref. https://issues.apache.org/jira/browse/SSHD-24
         // "AES256 and AES192 requires unlimited cryptography extension"
         for (Iterator<Factory.Named<Cipher>> i = avail.iterator(); i.hasNext();) {
@@ -144,10 +145,12 @@ public class DefaultConfig
                 final byte[] iv = new byte[c.getIVSize()];
                 c.init(Cipher.Mode.Encrypt, key, iv);
             } catch (Exception e) {
-                log.warn("Disabling cipher `{}`: cipher strengths apparently limited by JCE policy", f.getName());
+                warn = true;
                 i.remove();
             }
         }
+        if (warn)
+            log.warn("Disabling high-strength ciphers: cipher strengths apparently limited by JCE policy");
 
         setCipherFactories(avail);
     }

src/main/java/net/schmizz/sshj/SSHClient.java

@@ -33,6 +33,7 @@ import net.schmizz.sshj.connection.channel.forwarded.RemotePortForwarder.Forward
 import net.schmizz.sshj.connection.channel.forwarded.X11Forwarder;
 import net.schmizz.sshj.connection.channel.forwarded.X11Forwarder.X11Channel;
 import net.schmizz.sshj.sftp.SFTPClient;
+import net.schmizz.sshj.sftp.SFTPEngine;
 import net.schmizz.sshj.sftp.StatefulSFTPClient;
 import net.schmizz.sshj.transport.Transport;
 import net.schmizz.sshj.transport.TransportException;
@@ -49,11 +50,14 @@ import net.schmizz.sshj.userauth.keyprovider.FileKeyProvider;
 import net.schmizz.sshj.userauth.keyprovider.KeyPairWrapper;
 import net.schmizz.sshj.userauth.keyprovider.KeyProvider;
 import net.schmizz.sshj.userauth.keyprovider.KeyProviderUtil;
+import net.schmizz.sshj.userauth.method.AuthKeyboardInteractive;
 import net.schmizz.sshj.userauth.method.AuthMethod;
 import net.schmizz.sshj.userauth.method.AuthPassword;
 import net.schmizz.sshj.userauth.method.AuthPublickey;
+import net.schmizz.sshj.userauth.method.PasswordResponseProvider;
 import net.schmizz.sshj.userauth.password.PasswordFinder;
 import net.schmizz.sshj.userauth.password.PasswordUtils;
+import net.schmizz.sshj.userauth.password.Resource;
 import net.schmizz.sshj.xfer.scp.SCPFileTransfer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -87,18 +91,19 @@ import java.util.List;
  * <p/>
  * <em>A simple example:</em>
  * <p/>
- * <p/>
  * <pre>
  * client = new SSHClient();
  * client.initUserKnownHosts();
  * client.connect(&quot;hostname&quot;);
- * try
- * {
+ * try {
  *     client.authPassword(&quot;username&quot;, &quot;password&quot;);
- *     client.startSession().exec(&quot;true&quot;);
- *     client.getConnection().join();
- * } finally
- * {
+ *     final Session session = client.startSession();
+ *     try {
+ *          session.exec(&quot;true&quot;);
+ *          client.getConnection().join();
+ *     } finally {
+ *          session.close();
+ *    } finally {
  *     client.disconnect();
  * }
  * </pre>
@@ -116,7 +121,6 @@ public class SSHClient
     /** Logger */
     protected final Logger log = LoggerFactory.getLogger(getClass());
 
-
     /** Transport layer */
     protected final Transport trans;
 
@@ -154,19 +158,18 @@ public class SSHClient
     }
 
     /**
-     * Add a {@link HostKeyVerifier} that will verify any host at given {@code hostname:port} and a host key that has
-     * the given {@code fingerprint}, e.g. {@code "4b:69:6c:72:6f:79:20:77:61:73:20:68:65:72:65:21"}
+     * Add a {@link HostKeyVerifier} that will verify any host that's able to claim a host key with the given {@code
+     * fingerprint}, e.g. {@code "4b:69:6c:72:6f:79:20:77:61:73:20:68:65:72:65:21"}
      *
-     * @param host        the hostname / IP address
-     * @param port        the port for which the {@code fingerprint} applies
      * @param fingerprint expected fingerprint in colon-delimited format (16 octets in hex delimited by a colon)
      *
      * @see SecurityUtils#getFingerprint
      */
-    public void addHostKeyVerifier(final String host, final int port, final String fingerprint) {
+    public void addHostKeyVerifier(final String fingerprint) {
         addHostKeyVerifier(new HostKeyVerifier() {
+            @Override
             public boolean verify(String h, int p, PublicKey k) {
-                return host.equals(h) && port == p && SecurityUtils.getFingerprint(k).equals(fingerprint);
+                return SecurityUtils.getFingerprint(k).equals(fingerprint);
             }
         });
     }
@@ -202,36 +205,8 @@ public class SSHClient
     }
 
     /**
-     * Authenticate {@code username} using the {@code "password"} authentication method. The {@code password} array is
-     * blanked out after use.
-     *
-     * @param username user to authenticate
-     * @param password the password to use for authentication
-     *
-     * @throws UserAuthException  in case of authentication failure
-     * @throws TransportException if there was a transport-layer error
-     */
-    public void authPassword(String username, char[] password)
-            throws UserAuthException, TransportException {
-        authPassword(username, PasswordUtils.createOneOff(password));
-    }
-
-    /**
-     * Authenticate {@code username} using the {@code "password"} authentication method.
-     *
-     * @param username user to authenticate
-     * @param pfinder  the {@link PasswordFinder} to use for authentication
-     *
-     * @throws UserAuthException  in case of authentication failure
-     * @throws TransportException if there was a transport-layer error
-     */
-    public void authPassword(String username, PasswordFinder pfinder)
-            throws UserAuthException, TransportException {
-        auth(username, new AuthPassword(pfinder));
-    }
-
-    /**
-     * Authenticate {@code username} using the {@code "password"} authentication method.
+     * Authenticate {@code username} using the {@code "password"} authentication method and as a fallback basic
+     * challenge-response authentication.
      *
      * @param username user to authenticate
      * @param password the password to use for authentication
@@ -244,6 +219,52 @@ public class SSHClient
         authPassword(username, password.toCharArray());
     }
 
+    /**
+     * Authenticate {@code username} using the {@code "password"} authentication method and as a fallback basic
+     * challenge-response authentication.. The {@code password} array is blanked out after use.
+     *
+     * @param username user to authenticate
+     * @param password the password to use for authentication
+     *
+     * @throws UserAuthException  in case of authentication failure
+     * @throws TransportException if there was a transport-layer error
+     */
+    public void authPassword(final String username, final char[] password)
+            throws UserAuthException, TransportException {
+        try {
+            authPassword(username, new PasswordFinder() {
+
+                @Override
+                public char[] reqPassword(Resource<?> resource) {
+                    return password.clone();
+                }
+
+                @Override
+                public boolean shouldRetry(Resource<?> resource) {
+                    return false;
+                }
+
+            });
+        } finally {
+            PasswordUtils.blankOut(password);
+        }
+    }
+
+    /**
+     * Authenticate {@code username} using the {@code "password"} authentication method and as a fallback basic
+     * challenge-response authentication.
+     *
+     * @param username user to authenticate
+     * @param pfinder  the {@link PasswordFinder} to use for authentication
+     *
+     * @throws UserAuthException  in case of authentication failure
+     * @throws TransportException if there was a transport-layer error
+     */
+    public void authPassword(String username, PasswordFinder pfinder)
+            throws UserAuthException, TransportException {
+        auth(username, new AuthPassword(pfinder), new AuthKeyboardInteractive(new PasswordResponseProvider(pfinder)));
+    }
+
     /**
      * Authenticate {@code username} using the {@code "publickey"} authentication method, with keys from some common
      * locations on the file system. This method relies on {@code ~/.ssh/id_rsa} and {@code ~/.ssh/id_dsa}.
@@ -574,7 +595,7 @@ public class SSHClient
     public SFTPClient newSFTPClient()
             throws IOException {
         assert isConnected() && isAuthenticated();
-        return new SFTPClient(this);
+        return new SFTPClient(new SFTPEngine(this).init());
     }
 
     /**
@@ -587,6 +608,7 @@ public class SSHClient
         doKex();
     }
 
+    @Override
     public Session startSession()
             throws ConnectionException, TransportException {
         assert isConnected() && isAuthenticated();
@@ -607,7 +629,7 @@ public class SSHClient
      * @throws TransportException     if an error occurs during renegotiation
      */
     public void useCompression()
-            throws ClassNotFoundException, TransportException {
+            throws TransportException {
         trans.getConfig().setCompressionFactories(Arrays.asList(
                 new DelayedZlibCompression.Factory(),
                 new ZlibCompression.Factory(),

src/main/java/net/schmizz/sshj/SocketClient.java

@@ -120,8 +120,6 @@ abstract class SocketClient {
             output.close();
             output = null;
         }
-        input = null;
-        output = null;
     }
 
     public boolean isConnected() {

src/main/java/net/schmizz/sshj/common/Buffer.java

@@ -38,12 +38,7 @@ package net.schmizz.sshj.common;
 import java.io.UnsupportedEncodingException;
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
-import java.security.KeyFactory;
 import java.security.PublicKey;
-import java.security.interfaces.DSAPublicKey;
-import java.security.interfaces.RSAPublicKey;
-import java.security.spec.DSAPublicKeySpec;
-import java.security.spec.RSAPublicKeySpec;
 import java.util.Arrays;
 
 public class Buffer<T extends Buffer<T>> {
@@ -445,71 +440,34 @@ public class Buffer<T extends Buffer<T>> {
      * This is useful when a plaintext password needs to be sent. If {@code passwd} is {@code null}, an empty string is
      * written.
      *
-     * @param passwd (null-ok) the password as a character array
+     * @param str (null-ok) the password as a character array
      *
      * @return this
      */
     @SuppressWarnings("unchecked")
-    public T putPassword(char[] passwd) {
-        if (passwd == null)
+    public T putSensitiveString(char[] str) {
+        if (str == null)
             return putString("");
-        putInt(passwd.length);
-        ensureCapacity(passwd.length);
-        for (char c : passwd)
+        putInt(str.length);
+        ensureCapacity(str.length);
+        for (char c : str)
             data[wpos++] = (byte) c;
-        Arrays.fill(passwd, ' ');
+        Arrays.fill(str, ' ');
         return (T) this;
     }
 
     public PublicKey readPublicKey() {
         try {
-            switch (KeyType.fromString(readString())) {
-                case RSA: {
-                    BigInteger e = readMPInt();
-                    BigInteger n = readMPInt();
-                    KeyFactory keyFactory = SecurityUtils.getKeyFactory("RSA");
-                    return keyFactory.generatePublic(new RSAPublicKeySpec(n, e));
-                }
-                case DSA: {
-                    BigInteger p = readMPInt();
-                    BigInteger q = readMPInt();
-                    BigInteger g = readMPInt();
-                    BigInteger y = readMPInt();
-                    KeyFactory keyFactory = SecurityUtils.getKeyFactory("DSA");
-                    return keyFactory.generatePublic(new DSAPublicKeySpec(y, p, q, g));
-                }
-                default:
-                    assert false;
-            }
+            final String type = readString();
+            return KeyType.fromString(type).readPubKeyFromBuffer(type, this);
         } catch (GeneralSecurityException e) {
             throw new SSHRuntimeException(e);
         }
-        return null;
     }
 
     @SuppressWarnings("unchecked")
     public T putPublicKey(PublicKey key) {
-        final KeyType type = KeyType.fromKey(key);
-        switch (type) {
-            case RSA: {
-                final RSAPublicKey rsaKey = (RSAPublicKey) key;
-                putString(type.toString()) // ssh-rsa
-                        .putMPInt(rsaKey.getPublicExponent()) // e
-                        .putMPInt(rsaKey.getModulus()); // n
-                break;
-            }
-            case DSA: {
-                final DSAPublicKey dsaKey = (DSAPublicKey) key;
-                putString(type.toString()) // ssh-dss
-                        .putMPInt(dsaKey.getParams().getP()) // p
-                        .putMPInt(dsaKey.getParams().getQ()) // q
-                        .putMPInt(dsaKey.getParams().getG()) // g
-                        .putMPInt(dsaKey.getY()); // y
-                break;
-            }
-            default:
-                throw new SSHRuntimeException("Don't know how to encode key: " + key);
-        }
+        KeyType.fromKey(key).putPubKeyIntoBuffer(key, this);
         return (T) this;
     }
 

src/main/java/net/schmizz/sshj/common/DisconnectReason.java

@@ -18,39 +18,32 @@ package net.schmizz.sshj.common;
 /** Disconnect error codes */
 public enum DisconnectReason {
 
-    UNKNOWN(0),
-    HOST_NOT_ALLOWED_TO_CONNECT(1),
-    PROTOCOL_ERROR(2),
-    KEY_EXCHANGE_FAILED(3),
-    HOST_AUTHENTICATION_FAILED(4),
-    RESERVED(4),
-    MAC_ERROR(5),
-    COMPRESSION_ERROR(6),
-    SERVICE_NOT_AVAILABLE(7),
-    PROTOCOL_VERSION_NOT_SUPPORTED(8),
-    HOST_KEY_NOT_VERIFIABLE(9),
-    CONNECTION_LOST(10),
-    BY_APPLICATION(11),
-    TOO_MANY_CONNECTIONS(12),
-    AUTH_CANCELLED_BY_USER(13),
-    NO_MORE_AUTH_METHODS_AVAILABLE(14),
-    ILLEGAL_USER_NAME(15);
+    UNKNOWN,
+    HOST_NOT_ALLOWED_TO_CONNECT,
+    PROTOCOL_ERROR,
+    KEY_EXCHANGE_FAILED,
+    RESERVED,
+    MAC_ERROR,
+    COMPRESSION_ERROR,
+    SERVICE_NOT_AVAILABLE,
+    PROTOCOL_VERSION_NOT_SUPPORTED,
+    HOST_KEY_NOT_VERIFIABLE,
+    CONNECTION_LOST,
+    BY_APPLICATION,
+    TOO_MANY_CONNECTIONS,
+    AUTH_CANCELLED_BY_USER,
+    NO_MORE_AUTH_METHODS_AVAILABLE,
+    ILLEGAL_USER_NAME;
 
     public static DisconnectReason fromInt(int code) {
-        for (DisconnectReason dc : values())
-            if (dc.code == code)
-                return dc;
-        return UNKNOWN;
-    }
-
-    private final int code;
-
-    private DisconnectReason(int code) {
-        this.code = code;
+        final int len = values().length;
+        if (code < 0 || code > len)
+            return UNKNOWN;
+        return values()[code];
     }
 
     public int toInt() {
-        return code;
+        return ordinal();
     }
 
 }

src/main/java/net/schmizz/sshj/common/KeyType.java

@@ -15,47 +15,117 @@
  */
 package net.schmizz.sshj.common;
 
+import java.math.BigInteger;
+import java.security.GeneralSecurityException;
 import java.security.Key;
+import java.security.KeyFactory;
+import java.security.PublicKey;
 import java.security.interfaces.DSAPrivateKey;
 import java.security.interfaces.DSAPublicKey;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
+import java.security.spec.DSAPublicKeySpec;
+import java.security.spec.RSAPublicKeySpec;
 
 /** Type of key e.g. rsa, dsa */
 public enum KeyType {
 
     /** SSH identifier for RSA keys */
-    RSA("ssh-rsa", new KeyChecker() {
-        public boolean isMyType(Key key) {
+    RSA("ssh-rsa") {
+
+        @Override
+        public PublicKey readPubKeyFromBuffer(String type, Buffer<?> buf)
+                throws GeneralSecurityException {
+            final BigInteger e = buf.readMPInt();
+            final BigInteger n = buf.readMPInt();
+            final KeyFactory keyFactory = SecurityUtils.getKeyFactory("RSA");
+            return keyFactory.generatePublic(new RSAPublicKeySpec(n, e));
+        }
+
+        @Override
+        public void putPubKeyIntoBuffer(PublicKey pk, Buffer<?> buf) {
+            final RSAPublicKey rsaKey = (RSAPublicKey) pk;
+            buf.putString(sType)
+                    .putMPInt(rsaKey.getPublicExponent()) // e
+                    .putMPInt(rsaKey.getModulus()); // n
+        }
+
+        @Override
+        protected boolean isMyType(Key key) {
             return (key instanceof RSAPublicKey || key instanceof RSAPrivateKey);
         }
-    }),
+
+    },
 
     /** SSH identifier for DSA keys */
-    DSA("ssh-dss", new KeyChecker() {
-        public boolean isMyType(Key key) {
+    DSA("ssh-dss") {
+
+        @Override
+        public PublicKey readPubKeyFromBuffer(String type, Buffer<?> buf)
+                throws GeneralSecurityException {
+            final BigInteger p = buf.readMPInt();
+            final BigInteger q = buf.readMPInt();
+            final BigInteger g = buf.readMPInt();
+            final BigInteger y = buf.readMPInt();
+            final KeyFactory keyFactory = SecurityUtils.getKeyFactory("DSA");
+            return keyFactory.generatePublic(new DSAPublicKeySpec(y, p, q, g));
+        }
+
+        @Override
+        public void putPubKeyIntoBuffer(PublicKey pk, Buffer<?> buf) {
+            final DSAPublicKey dsaKey = (DSAPublicKey) pk;
+            buf.putString(sType)
+                    .putMPInt(dsaKey.getParams().getP()) // p
+                    .putMPInt(dsaKey.getParams().getQ()) // q
+                    .putMPInt(dsaKey.getParams().getG()) // g
+                    .putMPInt(dsaKey.getY()); // y
+        }
+
+        @Override
+        protected boolean isMyType(Key key) {
             return (key instanceof DSAPublicKey || key instanceof DSAPrivateKey);
         }
-    }),
+
+    },
 
     /** Unrecognized */
-    UNKNOWN("unknown", null);
+    UNKNOWN("unknown") {
 
-    private static interface KeyChecker {
-        boolean isMyType(Key key);
-    }
+        @Override
+        public PublicKey readPubKeyFromBuffer(String type, Buffer<?> buf)
+                throws GeneralSecurityException {
+            throw new UnsupportedOperationException("Don't know how to decode key:" + type);
+        }
 
-    private final String sType;
-    private final KeyChecker checker;
+        @Override
+        public void putPubKeyIntoBuffer(PublicKey pk, Buffer<?> buf) {
+            throw new UnsupportedOperationException("Don't know how to encode key: " + pk);
+        }
 
-    private KeyType(String type, KeyChecker checker) {
+        @Override
+        protected boolean isMyType(Key key) {
+            return false;
+        }
+
+    };
+
+
+    protected final String sType;
+
+    private KeyType(String type) {
         this.sType = type;
-        this.checker = checker;
     }
 
+    public abstract PublicKey readPubKeyFromBuffer(String type, Buffer<?> buf)
+            throws GeneralSecurityException;
+
+    public abstract void putPubKeyIntoBuffer(PublicKey pk, Buffer<?> buf);
+
+    protected abstract boolean isMyType(Key key);
+
     public static KeyType fromKey(Key key) {
         for (KeyType kt : values())
-            if (kt.checker != null && kt.checker.isMyType((key)))
+            if (kt.isMyType((key)))
                 return kt;
         return UNKNOWN;
     }

src/main/java/net/schmizz/sshj/common/Message.java

@@ -18,6 +18,7 @@ package net.schmizz.sshj.common;
 /** SSH message identifiers */
 public enum Message {
 
+    UNKNOWN(0),
     DISCONNECT(1),
     IGNORE(2),
     UNIMPLEMENTED(3),
@@ -67,8 +68,11 @@ public enum Message {
 
     static {
         for (Message c : Message.values())
-            if (cache[c.toByte()] == null)
-                cache[c.toByte()] = c;
+            cache[c.toByte()] = c;
+        for (int i = 0; i < 256; i++) {
+            if (cache[i] == null)
+                cache[i] = UNKNOWN;
+        }
     }
 
     public static Message fromByte(byte b) {

src/main/java/net/schmizz/sshj/common/SSHException.java

@@ -48,6 +48,7 @@ public class SSHException
 
     public static final ExceptionChainer<SSHException> chainer = new ExceptionChainer<SSHException>() {
 
+        @Override
         public SSHException chain(Throwable t) {
             if (t instanceof SSHException)
                 return (SSHException) t;

src/main/java/net/schmizz/sshj/common/SSHPacket.java

@@ -76,11 +76,7 @@ public class SSHPacket
      * @return the message identifier
      */
     public Message readMessageID() {
-        byte b = readByte();
-        Message cmd = Message.fromByte(b);
-        if (cmd == null)
-            throw new BufferException("Unknown message ID: " + b);
-        return cmd;
+        return Message.fromByte(readByte());
     }
 
     /**

src/main/java/net/schmizz/sshj/common/StreamCopier.java

@@ -22,7 +22,6 @@ import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.util.Arrays;
 
 public class StreamCopier
         extends Thread {
@@ -34,18 +33,23 @@ public class StreamCopier
     }
 
     public static ErrorCallback closeOnErrorCallback(final Closeable... toClose) {
-        final Closeable[] closeables = Arrays.copyOf(toClose, toClose.length);
         return new ErrorCallback() {
+            @Override
             public void onError(IOException ioe) {
-                IOUtils.closeQuietly(closeables);
+                IOUtils.closeQuietly(toClose);
             }
         };
     }
 
-    public static long copy(InputStream in, OutputStream out, int bufSize, boolean keepFlushing)
+    public interface Listener {
+        void reportProgress(long transferred);
+    }
+
+    public static long copy(InputStream in, OutputStream out, int bufSize, boolean keepFlushing, Listener listener)
             throws IOException {
         long count = 0;
 
+        final boolean reportProgress = listener != null;
         final long startTime = System.currentTimeMillis();
 
         final byte[] buf = new byte[bufSize];
@@ -55,6 +59,8 @@ public class StreamCopier
             count += read;
             if (keepFlushing)
                 out.flush();
+            if (reportProgress)
+                listener.reportProgress(count);
         }
         if (!keepFlushing)
             out.flush();
@@ -66,6 +72,11 @@ public class StreamCopier
         return count;
     }
 
+    public static long copy(InputStream in, OutputStream out, int bufSize, boolean keepFlushing)
+            throws IOException {
+        return copy(in, out, bufSize, keepFlushing, null);
+    }
+
     public static String copyStreamToString(InputStream stream)
             throws IOException {
         final StringBuilder sb = new StringBuilder();
@@ -75,7 +86,7 @@ public class StreamCopier
         return sb.toString();
     }
 
-    private final Logger log;
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final InputStream in;
     private final OutputStream out;
@@ -84,6 +95,7 @@ public class StreamCopier
     private boolean keepFlushing = true;
 
     private ErrorCallback errCB = new ErrorCallback() {
+        @Override
         public void onError(IOException ioe) {
         }
     }; // Default null cb
@@ -91,9 +103,7 @@ public class StreamCopier
     public StreamCopier(String name, InputStream in, OutputStream out) {
         this.in = in;
         this.out = out;
-
-        setName("streamCopier");
-        log = LoggerFactory.getLogger(name);
+        setName(name);
     }
 
     public StreamCopier bufSize(int size) {

src/main/java/net/schmizz/sshj/connection/ConnectionException.java

@@ -24,6 +24,7 @@ public class ConnectionException
         extends SSHException {
 
     public static final ExceptionChainer<ConnectionException> chainer = new ExceptionChainer<ConnectionException>() {
+        @Override
         public ConnectionException chain(Throwable t) {
             if (t instanceof ConnectionException)
                 return (ConnectionException) t;

src/main/java/net/schmizz/sshj/connection/ConnectionImpl.java

@@ -30,6 +30,7 @@ import net.schmizz.sshj.connection.channel.forwarded.ForwardedChannelOpener;
 import net.schmizz.sshj.transport.Transport;
 import net.schmizz.sshj.transport.TransportException;
 
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.Map;
 import java.util.Queue;
@@ -63,19 +64,23 @@ public class ConnectionImpl
         super("ssh-connection", trans);
     }
 
+    @Override
     public void attach(Channel chan) {
         log.info("Attaching `{}` channel (#{})", chan.getType(), chan.getID());
         channels.put(chan.getID(), chan);
     }
 
+    @Override
     public Channel get(int id) {
         return channels.get(id);
     }
 
+    @Override
     public ForwardedChannelOpener get(String chanType) {
         return openers.get(chanType);
     }
 
+    @Override
     public void forget(Channel chan) {
         log.info("Forgetting `{}` channel (#{})", chan.getType(), chan.getID());
         channels.remove(chan.getID());
@@ -85,11 +90,13 @@ public class ConnectionImpl
         }
     }
 
+    @Override
     public void forget(ForwardedChannelOpener opener) {
         log.info("Forgetting opener for `{}` channels: {}", opener.getChannelType(), opener);
         openers.remove(opener.getChannelType());
     }
 
+    @Override
     public void attach(ForwardedChannelOpener opener) {
         log.info("Attaching opener for `{}` channels: {}", opener.getChannelType(), opener);
         openers.put(opener.getChannelType(), opener);
@@ -146,26 +153,32 @@ public class ConnectionImpl
         channels.clear();
     }
 
+    @Override
     public int getMaxPacketSize() {
         return maxPacketSize;
     }
 
+    @Override
     public Transport getTransport() {
         return trans;
     }
 
+    @Override
     public void setMaxPacketSize(int maxPacketSize) {
         this.maxPacketSize = maxPacketSize;
     }
 
+    @Override
     public int getWindowSize() {
         return windowSize;
     }
 
+    @Override
     public void setWindowSize(int windowSize) {
         this.windowSize = windowSize;
     }
 
+    @Override
     public void join()
             throws InterruptedException {
         synchronized (internalSynchronizer) {
@@ -174,10 +187,12 @@ public class ConnectionImpl
         }
     }
 
+    @Override
     public int nextID() {
         return nextID.getAndIncrement();
     }
 
+    @Override
     public Future<SSHPacket, ConnectionException> sendGlobalRequest(String name, boolean wantReply,
                                                                     byte[] specifics)
             throws TransportException {
@@ -221,6 +236,7 @@ public class ConnectionImpl
         }
     }
 
+    @Override
     public void sendOpenFailure(int recipient, Reason reason, String message)
             throws TransportException {
         trans.write(new SSHPacket(Message.CHANNEL_OPEN_FAILURE)
@@ -233,9 +249,9 @@ public class ConnectionImpl
     public void notifyDisconnect()
             throws SSHException {
         super.notifyDisconnect();
-        FutureUtils.alertAll(new ConnectionException("Disconnected."), globalReqFutures);
-        for (Channel chan : channels.values())
-            chan.close();
+        final ConnectionException ex = new ConnectionException("Disconnected.");
+        FutureUtils.alertAll(ex, globalReqFutures);
+        ErrorNotifiable.Util.alertAll(ex, new HashSet<Channel>(channels.values()));
     }
 
 }

src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java

@@ -62,7 +62,7 @@ public abstract class AbstractChannel
         implements Channel {
 
     /** Logger */
-    protected final Logger log;
+    protected final Logger log = LoggerFactory.getLogger(getClass());
 
     /** Transport layer */
     protected final Transport trans;
@@ -78,12 +78,12 @@ public abstract class AbstractChannel
 
     private final Queue<Event<ConnectionException>> chanReqResponseEvents = new LinkedList<Event<ConnectionException>>();
 
-    /* The lock used by #newEvent to create open & close events */
+    /* The lock used by to create the open & close events */
     private final ReentrantLock lock = new ReentrantLock();
     /** Channel open event */
     protected final Event<ConnectionException> open;
     /** Channel close event */
-    private final Event<ConnectionException> close;
+    protected final Event<ConnectionException> close;
 
     /* Access to these fields should be synchronized using this object */
     private boolean eofSent;
@@ -109,9 +109,7 @@ public abstract class AbstractChannel
 
         id = conn.nextID();
 
-        log = LoggerFactory.getLogger("chan#" + id);
-
-        lwin = new Window.Local(id, conn.getWindowSize(), conn.getMaxPacketSize());
+        lwin = new Window.Local(conn.getWindowSize(), conn.getMaxPacketSize());
         in = new ChannelInputStream(this, trans, lwin);
 
         open = new Event<ConnectionException>("chan#" + id + " / " + "open", ConnectionException.chainer, lock);
@@ -120,51 +118,62 @@ public abstract class AbstractChannel
 
     protected void init(int recipient, int remoteWinSize, int remoteMaxPacketSize) {
         this.recipient = recipient;
-        rwin = new Window.Remote(id, remoteWinSize, remoteMaxPacketSize);
+        rwin = new Window.Remote(remoteWinSize, remoteMaxPacketSize);
         out = new ChannelOutputStream(this, trans, rwin);
         log.info("Initialized - {}", this);
     }
 
+    @Override
     public boolean getAutoExpand() {
         return autoExpand;
     }
 
+    @Override
     public int getID() {
         return id;
     }
 
+    @Override
     public InputStream getInputStream() {
         return in;
     }
 
+    @Override
     public int getLocalMaxPacketSize() {
         return lwin.getMaxPacketSize();
     }
 
+    @Override
     public int getLocalWinSize() {
         return lwin.getSize();
     }
 
+    @Override
     public OutputStream getOutputStream() {
         return out;
     }
 
+    @Override
     public int getRecipient() {
         return recipient;
     }
 
+    @Override
     public int getRemoteMaxPacketSize() {
         return rwin.getMaxPacketSize();
     }
 
+    @Override
     public int getRemoteWinSize() {
         return rwin.getSize();
     }
 
+    @Override
     public String getType() {
         return type;
     }
 
+    @Override
     public void handle(Message msg, SSHPacket buf)
             throws ConnectionException, TransportException {
         switch (msg) {
@@ -223,6 +232,7 @@ public abstract class AbstractChannel
         IOUtils.closeQuietly(in, out);
     }
 
+    @Override
     public void notifyError(SSHException error) {
         log.debug("Channel #{} got notified of {}", getID(), error.toString());
 
@@ -235,10 +245,12 @@ public abstract class AbstractChannel
         finishOff();
     }
 
+    @Override
     public void setAutoExpand(boolean autoExpand) {
         this.autoExpand = autoExpand;
     }
 
+    @Override
     public void close()
             throws ConnectionException, TransportException {
         lock.lock();
@@ -255,6 +267,16 @@ public abstract class AbstractChannel
         }
     }
 
+    public void join()
+            throws ConnectionException {
+        close.await();
+    }
+
+    public void join(int timeout, TimeUnit unit)
+            throws ConnectionException {
+        close.await(timeout, unit);
+    }
+
     protected synchronized void sendClose()
             throws TransportException {
         try {
@@ -267,6 +289,7 @@ public abstract class AbstractChannel
         }
     }
 
+    @Override
     public synchronized boolean isOpen() {
         lock.lock();
         try {
@@ -289,7 +312,6 @@ public abstract class AbstractChannel
         rwin.expand(howMuch);
     }
 
-    /** Called when this channel's end-of-life has been reached. Subclasses may override but must call super. */
     protected void finishOff() {
         conn.forget(this);
         close.set();
@@ -317,7 +339,7 @@ public abstract class AbstractChannel
     protected void receiveInto(ChannelInputStream stream, SSHPacket buf)
             throws ConnectionException, TransportException {
         final int len = buf.readInt();
-        if (len < 0 || len > getLocalMaxPacketSize() || len != buf.available())
+        if (len < 0 || len > getLocalMaxPacketSize() || len > buf.available())
             throw new ConnectionException(DisconnectReason.PROTOCOL_ERROR, "Bad item length: " + len);
         if (log.isTraceEnabled())
             log.trace("IN #{}: {}", id, ByteArrayUtils.printHex(buf.array(), buf.rpos(), len));
@@ -371,6 +393,7 @@ public abstract class AbstractChannel
         in.eof();
     }
 
+    @Override
     public synchronized void sendEOF()
             throws TransportException {
         try {

src/main/java/net/schmizz/sshj/connection/channel/Channel.java

@@ -23,6 +23,7 @@ import net.schmizz.sshj.transport.TransportException;
 import java.io.Closeable;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.concurrent.TimeUnit;
 
 /** A channel is the basic medium for application-layer data on top of an SSH transport. */
 public interface Channel
@@ -34,13 +35,12 @@ public interface Channel
         /**
          * Request opening this channel from remote end.
          *
-         * @throws OpenFailException  in case the channel open request was rejected
-         * @throws net.schmizz.sshj.connection.ConnectionException
-         *                            other connection-layer error
-         * @throws TransportException error writing packets etc.
+         * @throws OpenFailException   in case the channel open request was rejected
+         * @throws ConnectionException other connection-layer error
+         * @throws TransportException  error writing packets etc.
          */
         void open()
-                throws OpenFailException, ConnectionException, TransportException;
+                throws ConnectionException, TransportException;
 
     }
 
@@ -77,6 +77,7 @@ public interface Channel
 
 
     /** Close this channel. */
+    @Override
     void close()
             throws TransportException, ConnectionException;
 
@@ -135,4 +136,10 @@ public interface Channel
      */
     void setAutoExpand(boolean autoExpand);
 
+    void join()
+            throws ConnectionException;
+
+    void join(int timeout, TimeUnit unit)
+            throws ConnectionException;
+
 }

src/main/java/net/schmizz/sshj/connection/channel/ChannelInputStream.java

@@ -59,7 +59,7 @@ public final class ChannelInputStream
         extends InputStream
         implements ErrorNotifiable {
 
-    private final Logger log;
+    private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final Channel chan;
     private final Transport trans;
@@ -71,8 +71,6 @@ public final class ChannelInputStream
     private SSHException error;
 
     public ChannelInputStream(Channel chan, Transport trans, Window.Local win) {
-        log = LoggerFactory.getLogger("<< chan#" + chan.getID() + " / input stream >>");
-
         this.chan = chan;
         this.trans = trans;
         this.win = win;
@@ -100,6 +98,7 @@ public final class ChannelInputStream
         }
     }
 
+    @Override
     public synchronized void notifyError(SSHException error) {
         this.error = error;
         eof();
@@ -109,7 +108,7 @@ public final class ChannelInputStream
     public int read()
             throws IOException {
         synchronized (b) {
-            return read(b, 0, 1) == -1 ? -1 : b[0];
+            return read(b, 0, 1) == -1 ? -1 : b[0] & 0xff;
         }
     }
 

src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java

@@ -54,7 +54,7 @@ public final class ChannelOutputStream
         implements ErrorNotifiable {
 
     private final Channel chan;
-    private Transport trans;
+    private final Transport trans;
     private final Window.Remote win;
     private final SSHPacket buffer = new SSHPacket();
     private final byte[] b = new byte[1];
@@ -102,6 +102,7 @@ public final class ChannelOutputStream
         }
     }
 
+    @Override
     public synchronized void notifyError(SSHException error) {
         this.error = error;
     }

src/main/java/net/schmizz/sshj/connection/channel/Window.java

@@ -17,13 +17,12 @@ package net.schmizz.sshj.connection.channel;
 
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.connection.ConnectionException;
-import net.schmizz.sshj.transport.TransportException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public abstract class Window {
 
-    protected final Logger log;
+    protected final Logger log = LoggerFactory.getLogger(getClass());
 
     protected final Object lock = new Object();
 
@@ -31,8 +30,7 @@ public abstract class Window {
 
     protected int size;
 
-    public Window(int chanID, String kindOfWindow, int initialWinSize, int maxPacketSize) {
-        log = LoggerFactory.getLogger("<< chan#" + chanID + " / " + kindOfWindow + " >>");
+    public Window(int initialWinSize, int maxPacketSize) {
         size = initialWinSize;
         this.maxPacketSize = maxPacketSize;
     }
@@ -71,8 +69,8 @@ public abstract class Window {
     public static final class Remote
             extends Window {
 
-        public Remote(int chanID, int initialWinSize, int maxPacketSize) {
-            super(chanID, "remote win", initialWinSize, maxPacketSize);
+        public Remote(int initialWinSize, int maxPacketSize) {
+            super(initialWinSize, maxPacketSize);
         }
 
         public void waitAndConsume(int howMuch)
@@ -99,14 +97,13 @@ public abstract class Window {
         private final int initialSize;
         private final int threshold;
 
-        public Local(int chanID, int initialWinSize, int maxPacketSize) {
-            super(chanID, "local win", initialWinSize, maxPacketSize);
+        public Local(int initialWinSize, int maxPacketSize) {
+            super(initialWinSize, maxPacketSize);
             this.initialSize = initialWinSize;
             threshold = Math.min(maxPacketSize * 20, initialSize / 4);
         }
 
-        public int neededAdjustment()
-                throws TransportException {
+        public int neededAdjustment() {
             synchronized (lock) {
                 return (size - threshold <= 0) ? (initialSize - size) : 0;
             }

src/main/java/net/schmizz/sshj/connection/channel/direct/AbstractDirectChannel.java

@@ -60,6 +60,7 @@ public abstract class AbstractDirectChannel
         conn.attach(this);
     }
 
+    @Override
     public void open()
             throws ConnectionException, TransportException {
         trans.write(buildOpenReq());

src/main/java/net/schmizz/sshj/connection/channel/direct/LocalPortForwarder.java

@@ -48,31 +48,32 @@ public class LocalPortForwarder {
 
             final ErrorCallback closer = StreamCopier.closeOnErrorCallback(this,
                                                                            new Closeable() {
+                                                                               @Override
                                                                                public void close()
                                                                                        throws IOException {
                                                                                    sock.close();
                                                                                }
                                                                            });
 
-            new StreamCopier("chan2soc", getInputStream(), sock.getOutputStream()) //
-                    .bufSize(getLocalMaxPacketSize()) //
-                    .errorCallback(closer) //
-                    .daemon(true) //
+            new StreamCopier("chan2soc", getInputStream(), sock.getOutputStream())
+                    .bufSize(getLocalMaxPacketSize())
+                    .errorCallback(closer)
+                    .daemon(true)
                     .start();
 
-            new StreamCopier("soc2chan", sock.getInputStream(), getOutputStream()) //
-                    .bufSize(getRemoteMaxPacketSize()) //
-                    .errorCallback(closer) //
-                    .daemon(true) //
+            new StreamCopier("soc2chan", sock.getInputStream(), getOutputStream())
+                    .bufSize(getRemoteMaxPacketSize())
+                    .errorCallback(closer)
+                    .daemon(true)
                     .start();
         }
 
         @Override
         protected SSHPacket buildOpenReq() {
-            return super.buildOpenReq() //
-                    .putString(host) //
-                    .putInt(port) //
-                    .putString(ss.getInetAddress().getHostAddress()) //
+            return super.buildOpenReq()
+                    .putString(host)
+                    .putInt(port)
+                    .putString(ss.getInetAddress().getHostAddress())
                     .putInt(ss.getLocalPort());
         }
 
@@ -85,6 +86,19 @@ public class LocalPortForwarder {
     private final String host;
     private final int port;
 
+    /**
+     * Create a local port forwarder with specified binding ({@code listeningAddr}. It does not, however, start
+     * listening unless {@link #listen() explicitly told to}. The {@link javax.net.ServerSocketFactory#getDefault()
+     * default} server socket factory is used.
+     *
+     * @param conn          {@link Connection} implementation
+     * @param listeningAddr {@link SocketAddress} this forwarder will listen on, if {@code null} then an ephemeral port
+     *                      and valid local address will be picked to bind the server socket
+     * @param host          what host the SSH server will further forward to
+     * @param port          port on {@code toHost}
+     *
+     * @throws IOException if there is an error binding on specified {@code listeningAddr}
+     */
     public LocalPortForwarder(Connection conn, SocketAddress listeningAddr, String host, int port)
             throws IOException {
         this(ServerSocketFactory.getDefault(), conn, listeningAddr, host, port);
@@ -94,6 +108,7 @@ public class LocalPortForwarder {
      * Create a local port forwarder with specified binding ({@code listeningAddr}. It does not, however, start
      * listening unless {@link #listen() explicitly told to}.
      *
+     * @param ssf           factory to use for creating the server socket
      * @param conn          {@link Connection} implementation
      * @param listeningAddr {@link SocketAddress} this forwarder will listen on, if {@code null} then an ephemeral port
      *                      and valid local address will be picked to bind the server socket
@@ -112,16 +127,21 @@ public class LocalPortForwarder {
         ss.bind(listeningAddr);
     }
 
+    /** @return the address to which this forwarder is bound for listening */
     public SocketAddress getListeningAddress() {
         return ss.getLocalSocketAddress();
     }
 
-    /** Start listening for incoming connections and forward to remote host as a channel. */
+    /**
+     * Start listening for incoming connections and forward to remote host as a channel.
+     *
+     * @throws IOException
+     */
     public void listen()
             throws IOException {
         log.info("Listening on {}", ss.getLocalSocketAddress());
         Socket sock;
-        while (true) {
+        while (!Thread.currentThread().isInterrupted()) {
             sock = ss.accept();
             log.info("Got connection from {}", sock.getRemoteSocketAddress());
             DirectTCPIPChannel chan = new DirectTCPIPChannel(conn, sock);

src/main/java/net/schmizz/sshj/connection/channel/direct/SessionChannel.java

@@ -35,10 +35,7 @@
  */
 package net.schmizz.sshj.connection.channel.direct;
 
-import net.schmizz.sshj.common.Buffer;
-import net.schmizz.sshj.common.IOUtils;
-import net.schmizz.sshj.common.SSHPacket;
-import net.schmizz.sshj.common.StreamCopier;
+import net.schmizz.sshj.common.*;
 import net.schmizz.sshj.connection.Connection;
 import net.schmizz.sshj.connection.ConnectionException;
 import net.schmizz.sshj.connection.channel.ChannelInputStream;
@@ -46,16 +43,19 @@ import net.schmizz.sshj.transport.TransportException;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.HashMap;
+import java.util.Collections;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 
-/** {@link Session} implementation. */
-public class
-        SessionChannel
+/**
+ * {@link Session} implementation.
+ */
+public class SessionChannel
         extends AbstractDirectChannel
         implements Session, Session.Command, Session.Shell, Session.Subsystem {
 
+    private final ChannelInputStream err = new ChannelInputStream(this, trans, lwin);
+
     private Integer exitStatus;
 
     private Signal exitSignal;
@@ -64,28 +64,19 @@ public class
 
     private Boolean canDoFlowControl;
 
-    private ChannelInputStream err = new ChannelInputStream(this, trans, lwin);
+    private boolean usedUp;
 
     public SessionChannel(Connection conn) {
         super(conn, "session");
     }
 
+    @Override
     public void allocateDefaultPTY()
             throws ConnectionException, TransportException {
-        // TODO FIXME (maybe?): These modes were originally copied from what SSHD was doing;
-        // and then the echo modes were set to 0 to better serve the PTY example.
-        // Not sure what default PTY modes should be.
-        final Map<PTYMode, Integer> modes = new HashMap<PTYMode, Integer>();
-        modes.put(PTYMode.ISIG, 1);
-        modes.put(PTYMode.ICANON, 1);
-        modes.put(PTYMode.ECHO, 0);
-        modes.put(PTYMode.ECHOE, 0);
-        modes.put(PTYMode.ECHOK, 0);
-        modes.put(PTYMode.ECHONL, 0);
-        modes.put(PTYMode.NOFLSH, 0);
-        allocatePTY("vt100", 0, 0, 0, 0, modes);
+        allocatePTY("dummy", 80, 24, 0, 0, Collections.<PTYMode, Integer>emptyMap());
     }
 
+    @Override
     public void allocatePTY(String term, int cols, int rows, int width, int height, Map<PTYMode, Integer> modes)
             throws ConnectionException, TransportException {
         sendChannelRequest(
@@ -101,10 +92,12 @@ public class
         ).await(conn.getTimeout(), TimeUnit.SECONDS);
     }
 
+    @Override
     public Boolean canDoFlowControl() {
         return canDoFlowControl;
     }
 
+    @Override
     public void changeWindowDimensions(int cols, int rows, int width, int height)
             throws TransportException {
         sendChannelRequest(
@@ -118,35 +111,44 @@ public class
         );
     }
 
+    @Override
     public Command exec(String command)
             throws ConnectionException, TransportException {
+        checkReuse();
         log.info("Will request to exec `{}`", command);
         sendChannelRequest("exec", true, new Buffer.PlainBuffer().putString(command))
                 .await(conn.getTimeout(), TimeUnit.SECONDS);
+        usedUp = true;
         return this;
     }
 
+    @Override
     public String getErrorAsString()
             throws IOException {
         return StreamCopier.copyStreamToString(err);
     }
 
+    @Override
     public InputStream getErrorStream() {
         return err;
     }
 
+    @Override
     public String getExitErrorMessage() {
         return exitErrMsg;
     }
 
+    @Override
     public Signal getExitSignal() {
         return exitSignal;
     }
 
+    @Override
     public Integer getExitStatus() {
         return exitStatus;
     }
 
+    @Override
     public String getOutputAsString()
             throws IOException {
         return StreamCopier.copyStreamToString(getInputStream());
@@ -168,9 +170,9 @@ public class
             super.handleRequest(req, buf);
     }
 
+    @Override
     public void reqX11Forwarding(String authProto, String authCookie, int screen)
-            throws ConnectionException,
-                   TransportException {
+            throws ConnectionException, TransportException {
         sendChannelRequest(
                 "x11-req",
                 true,
@@ -182,31 +184,40 @@ public class
         ).await(conn.getTimeout(), TimeUnit.SECONDS);
     }
 
+    @Override
     public void setEnvVar(String name, String value)
             throws ConnectionException, TransportException {
         sendChannelRequest("env", true, new Buffer.PlainBuffer().putString(name).putString(value))
                 .await(conn.getTimeout(), TimeUnit.SECONDS);
     }
 
+    @Override
     public void signal(Signal sig)
             throws TransportException {
         sendChannelRequest("signal", false, new Buffer.PlainBuffer().putString(sig.toString()));
     }
 
+    @Override
     public Shell startShell()
             throws ConnectionException, TransportException {
+        checkReuse();
         sendChannelRequest("shell", true, null).await(conn.getTimeout(), TimeUnit.SECONDS);
+        usedUp = true;
         return this;
     }
 
+    @Override
     public Subsystem startSubsystem(String name)
             throws ConnectionException, TransportException {
+        checkReuse();
         log.info("Will request `{}` subsystem", name);
         sendChannelRequest("subsystem", true, new Buffer.PlainBuffer().putString(name))
                 .await(conn.getTimeout(), TimeUnit.SECONDS);
+        usedUp = true;
         return this;
     }
 
+    @Override
     public Boolean getExitWasCoreDumped() {
         return wasCoreDumped;
     }
@@ -232,4 +243,15 @@ public class
             super.gotExtendedData(dataTypeCode, buf);
     }
 
-}
+    @Override
+    public void notifyError(SSHException error) {
+        err.notifyError(error);
+        super.notifyError(error);
+    }
+
+    private void checkReuse() {
+        if (usedUp)
+            throw new SSHRuntimeException("This session channel is all used up");
+    }
+
+}

src/main/java/net/schmizz/sshj/connection/channel/direct/Signal.java

@@ -19,21 +19,20 @@ package net.schmizz.sshj.connection.channel.direct;
 /** Various signals that may be sent or received. The signals are from POSIX and simply miss the {@code "SIG_"} prefix. */
 public enum Signal {
 
-    ABRT("ABRT"),
-    ALRM("ALRM"),
-    FPE("FPE"),
-    HUP("HUP"),
-    ILL("ILL"),
-    INT("INT"),
-    KILL("KILL"),
-    PIPE("PIPE"),
-    QUIT(
-            "QUIT"),
-    SEGV("SEGV"),
-    TERM("TERM"),
-    USR1("USR1"),
-    USR2("USR2"),
-    UNKNOWN("UNKNOWN");
+    ABRT,
+    ALRM,
+    FPE,
+    HUP,
+    ILL,
+    INT,
+    KILL,
+    PIPE,
+    QUIT,
+    SEGV,
+    TERM,
+    USR1,
+    USR2,
+    UNKNOWN;
 
     /**
      * Create from the string representation used when the signal is received as part of an SSH packet.
@@ -44,20 +43,9 @@ public enum Signal {
      */
     public static Signal fromString(String name) {
         for (Signal sig : Signal.values())
-            if (sig.name.equals(name))
+            if (sig.toString().equals(name))
                 return sig;
         return UNKNOWN;
     }
 
-    private final String name;
-
-    private Signal(String name) {
-        this.name = name;
-    }
-
-    @Override
-    public String toString() {
-        return name;
-    }
-
 }

src/main/java/net/schmizz/sshj/connection/channel/forwarded/AbstractForwardedChannel.java

@@ -62,6 +62,7 @@ public abstract class AbstractForwardedChannel
         init(recipient, remoteWinSize, remoteMaxPacketSize);
     }
 
+    @Override
     public void confirm()
             throws TransportException {
         log.info("Confirming `{}` channel #{}", getType(), getID());
@@ -74,16 +75,19 @@ public abstract class AbstractForwardedChannel
         open.set();
     }
 
+    @Override
     public void reject(Reason reason, String message)
             throws TransportException {
         log.info("Rejecting `{}` channel: {}", getType(), message);
         conn.sendOpenFailure(getRecipient(), reason, message);
     }
 
+    @Override
     public String getOriginatorIP() {
         return origIP;
     }
 
+    @Override
     public int getOriginatorPort() {
         return origPort;
     }

src/main/java/net/schmizz/sshj/connection/channel/forwarded/AbstractForwardedChannelOpener.java

@@ -40,14 +40,12 @@ public abstract class AbstractForwardedChannelOpener
         this.conn = conn;
     }
 
+    @Override
     public String getChannelType() {
         return chanType;
     }
 
-    /*
-    * Calls the listener with the new channel in a separate thread.
-    */
-
+    /** Calls the listener with the new channel in a separate thread. */
     protected void callListener(final ConnectListener listener, final Channel.Forwarded chan) {
         new Thread() {
 

src/main/java/net/schmizz/sshj/connection/channel/forwarded/RemotePortForwarder.java

@@ -128,13 +128,12 @@ public class RemotePortForwarder
         private final Forward fwd;
 
         public ForwardedTCPIPChannel(Connection conn, int recipient, int remoteWinSize, int remoteMaxPacketSize,
-                                     Forward fwd, String origIP, int origPort)
-                throws TransportException {
+                                     Forward fwd, String origIP, int origPort) {
             super(conn, TYPE, recipient, remoteWinSize, remoteMaxPacketSize, origIP, origPort);
             this.fwd = fwd;
         }
 
-        /** Returns the forwarding from which this channel originates. */
+        /** @return the forwarding from which this channel originates. */
         public Forward getParentForward() {
             return fwd;
         }
@@ -209,6 +208,7 @@ public class RemotePortForwarder
      * Internal API. Creates a {@link ForwardedTCPIPChannel} from the {@code CHANNEL_OPEN} request and calls associated
      * {@code ConnectListener} for that forward in a separate thread.
      */
+    @Override
     public void handleOpen(SSHPacket buf)
             throws ConnectionException, TransportException {
         final ForwardedTCPIPChannel chan = new ForwardedTCPIPChannel(conn, buf.readInt(), buf.readInt(), buf.readInt(),

src/main/java/net/schmizz/sshj/connection/channel/forwarded/SocketForwardingConnectListener.java

@@ -40,6 +40,7 @@ public class SocketForwardingConnectListener
     }
 
     /** On connect, confirm the channel and start forwarding. */
+    @Override
     public void gotConnect(Channel.Forwarded chan)
             throws IOException {
         log.info("New connection from " + chan.getOriginatorIP() + ":" + chan.getOriginatorPort());
@@ -54,6 +55,7 @@ public class SocketForwardingConnectListener
         chan.confirm();
 
         final ErrorCallback closer = StreamCopier.closeOnErrorCallback(chan, new Closeable() {
+            @Override
             public void close()
                     throws IOException {
                 sock.close();

src/main/java/net/schmizz/sshj/connection/channel/forwarded/X11Forwarder.java

@@ -52,10 +52,13 @@ public class X11Forwarder
     }
 
     /** Internal API */
+    @Override
     public void handleOpen(SSHPacket buf)
             throws ConnectionException, TransportException {
-        callListener(listener, new X11Channel(conn, buf.readInt(), buf.readInt(), buf.readInt(), buf.readString(), buf
-                .readInt()));
+        callListener(listener, new X11Channel(conn,
+                                              buf.readInt(),
+                                              buf.readInt(), buf.readInt(),
+                                              buf.readString(), buf.readInt()));
     }
 
     /** Stop handling {@code x11} channel open requests. De-registers itself with connection layer. */

src/main/java/net/schmizz/sshj/sftp/FileAttributes.java

@@ -25,6 +25,8 @@ import java.util.Set;
 
 public final class FileAttributes {
 
+    public static final FileAttributes EMPTY = new FileAttributes();
+
     public static enum Flag {
 
         SIZE(0x00000001),
@@ -58,7 +60,7 @@ public final class FileAttributes {
     private final long mtime;
     private final Map<String, String> ext = new HashMap<String, String>();
 
-    public FileAttributes() {
+    private FileAttributes() {
         size = atime = mtime = uid = gid = mask = 0;
         mode = new FileMode(0);
     }

src/main/java/net/schmizz/sshj/sftp/PacketReader.java

@@ -34,9 +34,11 @@ public class PacketReader
     private final Map<Long, Future<Response, SFTPException>> futures = new ConcurrentHashMap<Long, Future<Response, SFTPException>>();
     private final SFTPPacket<Response> packet = new SFTPPacket<Response>();
     private final byte[] lenBuf = new byte[4];
+    private final SFTPEngine engine;
 
-    public PacketReader(InputStream in) {
-        this.in = in;
+    public PacketReader(SFTPEngine engine) {
+        this.engine = engine;
+        this.in = engine.getSubsystem().getInputStream();
         setName("sftp reader");
     }
 
@@ -78,7 +80,7 @@ public class PacketReader
     @Override
     public void run() {
         try {
-            while (true) {
+            while (!isInterrupted()) {
                 readPacket();
                 handle();
             }
@@ -90,7 +92,7 @@ public class PacketReader
 
     public void handle()
             throws SFTPException {
-        Response resp = new Response(packet);
+        Response resp = new Response(packet, engine.getOperativeProtocolVersion());
         Future<Response, SFTPException> future = futures.remove(resp.getRequestID());
         log.debug("Received {} packet", resp.getType());
         if (future == null)

src/main/java/net/schmizz/sshj/sftp/PacketType.java

@@ -52,8 +52,7 @@ public enum PacketType {
 
     static {
         for (PacketType t : PacketType.values())
-            if (cache[t.toByte() & 0xff] == null)
-                cache[t.toByte() & 0xff] = t;
+            cache[t.toByte() & 0xff] = t;
     }
 
     private PacketType(int b) {

src/main/java/net/schmizz/sshj/sftp/PathComponents.java

@@ -15,7 +15,7 @@
  */
 package net.schmizz.sshj.sftp;
 
-class PathComponents {
+public class PathComponents {
 
     public static String adjustForParent(String parent, String path) {
         return (path.startsWith("/")) ? path // Absolute path, nothing to adjust

src/main/java/net/schmizz/sshj/sftp/PathHelper.java

@@ -17,13 +17,13 @@ package net.schmizz.sshj.sftp;
 
 import java.io.IOException;
 
-class PathHelper {
+public class PathHelper {
 
-    private final SFTPEngine sftp;
+    private final SFTPEngine engine;
     private String dotDir;
 
-    public PathHelper(SFTPEngine sftp) {
-        this.sftp = sftp;
+    public PathHelper(SFTPEngine engine) {
+        this.engine = engine;
     }
 
     public PathComponents getComponents(String path)
@@ -49,14 +49,14 @@ class PathHelper {
         }
     }
 
-    private String getDotDir()
+    private synchronized String getDotDir()
             throws IOException {
         return (dotDir != null) ? dotDir : (dotDir = canon("."));
     }
 
     private String canon(String path)
             throws IOException {
-        return sftp.canonicalize(path);
+        return engine.canonicalize(path);
     }
 
 }

src/main/java/net/schmizz/sshj/sftp/RandomAccessRemoteFile.java

@@ -61,6 +61,7 @@ public class RandomAccessRemoteFile
         return count;
     }
 
+    @Override
     public boolean readBoolean()
             throws IOException {
         final int ch = read();
@@ -69,6 +70,7 @@ public class RandomAccessRemoteFile
         return (ch != 0);
     }
 
+    @Override
     public byte readByte()
             throws IOException {
         final int ch = this.read();
@@ -77,6 +79,7 @@ public class RandomAccessRemoteFile
         return (byte) (ch);
     }
 
+    @Override
     public char readChar()
             throws IOException {
         final int ch1 = this.read();
@@ -86,21 +89,25 @@ public class RandomAccessRemoteFile
         return (char) ((ch1 << 8) + ch2);
     }
 
+    @Override
     public double readDouble()
             throws IOException {
         return Double.longBitsToDouble(readLong());
     }
 
+    @Override
     public float readFloat()
             throws IOException {
         return Float.intBitsToFloat(readInt());
     }
 
+    @Override
     public void readFully(byte[] b)
             throws IOException {
         readFully(b, 0, b.length);
     }
 
+    @Override
     public void readFully(byte[] b, int off, int len)
             throws IOException {
         int n = 0;
@@ -112,6 +119,7 @@ public class RandomAccessRemoteFile
         } while (n < len);
     }
 
+    @Override
     public int readInt()
             throws IOException {
         final int ch1 = read();
@@ -123,6 +131,7 @@ public class RandomAccessRemoteFile
         return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + ch4);
     }
 
+    @Override
     public String readLine()
             throws IOException {
         StringBuffer input = new StringBuffer();
@@ -151,11 +160,13 @@ public class RandomAccessRemoteFile
         return input.toString();
     }
 
+    @Override
     public long readLong()
             throws IOException {
         return ((long) (readInt()) << 32) + (readInt() & 0xFFFFFFFFL);
     }
 
+    @Override
     public short readShort()
             throws IOException {
         final int ch1 = this.read();
@@ -165,11 +176,13 @@ public class RandomAccessRemoteFile
         return (short) ((ch1 << 8) + ch2);
     }
 
+    @Override
     public String readUTF()
             throws IOException {
         return DataInputStream.readUTF(this);
     }
 
+    @Override
     public int readUnsignedByte()
             throws IOException {
         final int ch = this.read();
@@ -178,6 +191,7 @@ public class RandomAccessRemoteFile
         return ch;
     }
 
+    @Override
     public int readUnsignedShort()
             throws IOException {
         final int ch1 = this.read();
@@ -187,6 +201,7 @@ public class RandomAccessRemoteFile
         return (ch1 << 8) + ch2;
     }
 
+    @Override
     public int skipBytes(int n)
             throws IOException {
         if (n <= 0)
@@ -202,45 +217,53 @@ public class RandomAccessRemoteFile
         return (int) (newpos - pos);
     }
 
+    @Override
     public void write(int i)
             throws IOException {
         singleByte[0] = (byte) i;
         write(singleByte);
     }
 
+    @Override
     public void write(byte[] b)
             throws IOException {
         write(b, 0, b.length);
     }
 
+    @Override
     public void write(byte[] b, int off, int len)
             throws IOException {
         rf.write(fp, b, off, len);
         fp += (len - off);
     }
 
+    @Override
     public void writeBoolean(boolean v)
             throws IOException {
         write(v ? 1 : 0);
     }
 
+    @Override
     public void writeByte(int v)
             throws IOException {
         write(v);
     }
 
+    @Override
     public void writeBytes(String s)
             throws IOException {
         final byte[] b = s.getBytes();
         write(b, 0, b.length);
     }
 
+    @Override
     public void writeChar(int v)
             throws IOException {
         write((v >>> 8) & 0xFF);
         write(v & 0xFF);
     }
 
+    @Override
     public void writeChars(String s)
             throws IOException {
         final int clen = s.length();
@@ -255,16 +278,19 @@ public class RandomAccessRemoteFile
         write(b, 0, blen);
     }
 
+    @Override
     public void writeDouble(double v)
             throws IOException {
         writeLong(Double.doubleToLongBits(v));
     }
 
+    @Override
     public void writeFloat(float v)
             throws IOException {
         writeInt(Float.floatToIntBits(v));
     }
 
+    @Override
     public void writeInt(int v)
             throws IOException {
         write((v >>> 24) & 0xFF);
@@ -273,6 +299,7 @@ public class RandomAccessRemoteFile
         write(v & 0xFF);
     }
 
+    @Override
     public void writeLong(long v)
             throws IOException {
         write((int) (v >>> 56) & 0xFF);
@@ -285,12 +312,14 @@ public class RandomAccessRemoteFile
         write((int) v & 0xFF);
     }
 
+    @Override
     public void writeShort(int v)
             throws IOException {
         write((v >>> 8) & 0xFF);
         write(v & 0xFF);
     }
 
+    @Override
     public void writeUTF(String str)
             throws IOException {
         final DataOutputStream dos = new DataOutputStream(rf.new RemoteFileOutputStream(fp));

src/main/java/net/schmizz/sshj/sftp/RemoteDirectory.java

@@ -46,7 +46,7 @@ public class RemoteDirectory
                         if (!(name.equals(".") || name.equals("..")) && (filter == null || filter.accept(inf)))
                             rri.add(inf);
                     }
-                    break loop;
+                    break;
 
                 case STATUS:
                     res.ensureStatusIs(StatusCode.EOF);

src/main/java/net/schmizz/sshj/sftp/RemoteFile.java

@@ -38,8 +38,8 @@ public class RemoteFile
 
     public FileAttributes fetchAttributes()
             throws IOException {
-        return requester.doRequest(newRequest(PacketType.FSTAT)) //
-                .ensurePacketTypeIs(PacketType.ATTRS) //
+        return requester.doRequest(newRequest(PacketType.FSTAT))
+                .ensurePacketTypeIs(PacketType.ATTRS)
                 .readFileAttributes();
     }
 
@@ -73,11 +73,10 @@ public class RemoteFile
 
     public void write(long fileOffset, byte[] data, int off, int len)
             throws IOException {
-        requester.doRequest( //
-                             newRequest(PacketType.WRITE) //
-                                     .putUINT64(fileOffset) //
-                                     .putInt(len - off) //
-                                     .putRawBytes(data, off, len) //
+        requester.doRequest(newRequest(PacketType.WRITE)
+                .putUINT64(fileOffset)
+                .putInt(len - off)
+                .putRawBytes(data, off, len)
         ).ensureStatusPacketIsOK();
     }
 
@@ -171,7 +170,7 @@ public class RemoteFile
         @Override
         public int read()
                 throws IOException {
-            return read(b, 0, 1) == -1 ? -1 : b[0];
+            return read(b, 0, 1) == -1 ? -1 : b[0] & 0xff;
         }
 
         @Override

src/main/java/net/schmizz/sshj/sftp/RemoteResource.java

@@ -21,7 +21,7 @@ import org.slf4j.LoggerFactory;
 import java.io.Closeable;
 import java.io.IOException;
 
-abstract class RemoteResource
+public abstract class RemoteResource
         implements Closeable {
 
     /** Logger */
@@ -45,6 +45,7 @@ abstract class RemoteResource
         return requester.newRequest(type).putString(handle);
     }
 
+    @Override
     public void close()
             throws IOException {
         log.info("Closing `{}`", this);

src/main/java/net/schmizz/sshj/sftp/RemoteResourceInfo.java

@@ -55,12 +55,7 @@ public class RemoteResourceInfo {
 
     @Override
     public boolean equals(Object o) {
-        if (o instanceof RemoteResourceInfo) {
-            final RemoteResourceInfo that = (RemoteResourceInfo) o;
-            if (comps.equals(that.comps))
-                return true;
-        }
-        return false;
+        return o instanceof RemoteResourceInfo && (comps.equals(((RemoteResourceInfo) o).comps));
     }
 
     @Override

src/main/java/net/schmizz/sshj/sftp/Request.java

@@ -25,11 +25,10 @@ public class Request
     private final Future<Response, SFTPException> responseFuture;
 
     public Request(PacketType type, long reqID) {
-        super();
-        this.reqID = reqID;
+        super(type);
         this.type = type;
+        this.reqID = reqID;
         responseFuture = new Future<Response, SFTPException>("sftp / " + reqID, SFTPException.chainer);
-        putByte(type.toByte());
         putInt(reqID);
     }
 

src/main/java/net/schmizz/sshj/sftp/Response.java

@@ -47,15 +47,21 @@ public class Response
 
     }
 
+    private final int protocolVersion;
     private final PacketType type;
     private final long reqID;
 
-    public Response(Buffer<Response> pk) {
+    public Response(Buffer<Response> pk, int protocolVersion) {
         super(pk);
+        this.protocolVersion = protocolVersion;
         this.type = readType();
         this.reqID = readLong();
     }
 
+    public int getProtocolVersion() {
+        return protocolVersion;
+    }
+
     public long getRequestID() {
         return reqID;
     }
@@ -72,7 +78,7 @@ public class Response
             throws SFTPException {
         if (getType() != pt)
             if (getType() == PacketType.STATUS)
-                throw new SFTPException(readStatusCode(), readString());
+                error(readStatusCode());
             else
                 throw new SFTPException("Unexpected packet " + getType());
         return this;
@@ -85,10 +91,15 @@ public class Response
 
     public Response ensureStatusIs(StatusCode acceptable)
             throws SFTPException {
-        StatusCode sc = readStatusCode();
+        final StatusCode sc = readStatusCode();
         if (sc != acceptable)
-            throw new SFTPException(sc, readString());
+            error(sc);
         return this;
     }
 
+    protected String error(StatusCode sc)
+            throws SFTPException {
+        throw new SFTPException(sc, protocolVersion < 3 ? sc.toString() : readString());
+    }
+
 }

src/main/java/net/schmizz/sshj/sftp/SFTPClient.java

@@ -15,32 +15,36 @@
  */
 package net.schmizz.sshj.sftp;
 
-import net.schmizz.sshj.connection.channel.direct.SessionFactory;
 import net.schmizz.sshj.xfer.FilePermission;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.Closeable;
 import java.io.IOException;
+import java.util.Deque;
 import java.util.EnumSet;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 
-public class SFTPClient {
+public class SFTPClient
+        implements Closeable {
 
     /** Logger */
     protected final Logger log = LoggerFactory.getLogger(getClass());
 
-    private final SFTPEngine sftp;
+    private final SFTPEngine engine;
     private final SFTPFileTransfer xfer;
+    private final PathHelper pathHelper;
 
-    public SFTPClient(SessionFactory ssh)
-            throws IOException {
-        this.sftp = new SFTPEngine(ssh).init();
-        this.xfer = new SFTPFileTransfer(sftp);
+    public SFTPClient(SFTPEngine engine) {
+        this.engine = engine;
+        this.pathHelper = new PathHelper(engine);
+        this.xfer = new SFTPFileTransfer(engine);
     }
 
     public SFTPEngine getSFTPEngine() {
-        return sftp;
+        return engine;
     }
 
     public SFTPFileTransfer getFileTansfer() {
@@ -54,7 +58,7 @@ public class SFTPClient {
 
     public List<RemoteResourceInfo> ls(String path, RemoteResourceFilter filter)
             throws IOException {
-        final RemoteDirectory dir = sftp.openDir(path);
+        final RemoteDirectory dir = engine.openDir(path);
         try {
             return dir.scan(filter);
         } finally {
@@ -65,12 +69,12 @@ public class SFTPClient {
     public RemoteFile open(String filename, Set<OpenMode> mode, FileAttributes attrs)
             throws IOException {
         log.debug("Opening `{}`", filename);
-        return sftp.open(filename, mode, attrs);
+        return engine.open(filename, mode, attrs);
     }
 
     public RemoteFile open(String filename, Set<OpenMode> mode)
             throws IOException {
-        return open(filename, mode, new FileAttributes());
+        return open(filename, mode, FileAttributes.EMPTY);
     }
 
     public RemoteFile open(String filename)
@@ -80,36 +84,68 @@ public class SFTPClient {
 
     public void mkdir(String dirname)
             throws IOException {
-        sftp.makeDir(dirname);
+        engine.makeDir(dirname);
+    }
+
+    public void mkdirs(String path)
+            throws IOException {
+        final Deque<String> dirsToMake = new LinkedList<String>();
+        for (PathComponents current = pathHelper.getComponents(path); ; current = pathHelper
+                .getComponents(current.getParent())) {
+            final FileAttributes attrs = statExistence(current.getPath());
+            if (attrs == null) {
+                dirsToMake.push(current.getPath());
+            } else if (attrs.getType() != FileMode.Type.DIRECTORY) {
+                throw new SFTPException(current.getPath() + " exists but is not a directory");
+            } else {
+                break;
+            }
+        }
+        while (!dirsToMake.isEmpty()) {
+            mkdir(dirsToMake.pop());
+        }
+    }
+
+    public FileAttributes statExistence(String path)
+            throws IOException {
+        try {
+            return engine.stat(path);
+        } catch (SFTPException sftpe) {
+            if (sftpe.getStatusCode() == Response.StatusCode.NO_SUCH_FILE) {
+                return null;
+            } else {
+                throw sftpe;
+            }
+        }
     }
 
     public void rename(String oldpath, String newpath)
             throws IOException {
-        sftp.rename(oldpath, newpath);
+        engine.rename(oldpath, newpath);
     }
 
     public void rm(String filename)
             throws IOException {
-        sftp.remove(filename);
+        engine.remove(filename);
     }
 
     public void rmdir(String dirname)
             throws IOException {
-        sftp.removeDir(dirname);
+        engine.removeDir(dirname);
     }
 
     public void symlink(String linkpath, String targetpath)
             throws IOException {
-        sftp.symlink(linkpath, targetpath);
+        engine.symlink(linkpath, targetpath);
     }
 
     public int version() {
-        return sftp.getOperativeProtocolVersion();
+        return engine.getOperativeProtocolVersion();
     }
 
     public void setattr(String path, FileAttributes attrs)
             throws IOException {
-        sftp.setAttributes(path, attrs);
+        engine.setAttributes(path, attrs);
     }
 
     public int uid(String path)
@@ -149,17 +185,17 @@ public class SFTPClient {
 
     public String readlink(String path)
             throws IOException {
-        return sftp.readLink(path);
+        return engine.readLink(path);
     }
 
     public FileAttributes stat(String path)
             throws IOException {
-        return sftp.stat(path);
+        return engine.stat(path);
     }
 
     public FileAttributes lstat(String path)
             throws IOException {
-        return sftp.lstat(path);
+        return engine.lstat(path);
     }
 
     public void chown(String path, int uid)
@@ -184,7 +220,7 @@ public class SFTPClient {
 
     public String canonicalize(String path)
             throws IOException {
-        return sftp.canonicalize(path);
+        return engine.canonicalize(path);
     }
 
     public long size(String path)
@@ -202,4 +238,10 @@ public class SFTPClient {
         xfer.upload(source, dest);
     }
 
+    @Override
+    public void close()
+            throws IOException {
+        engine.close();
+    }
+
 }

src/main/java/net/schmizz/sshj/sftp/SFTPEngine.java

@@ -21,6 +21,7 @@ import net.schmizz.sshj.connection.channel.direct.SessionFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.EnumSet;
@@ -30,39 +31,34 @@ import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 public class SFTPEngine
-        implements Requester {
-
-    /** Logger */
-    private final Logger log = LoggerFactory.getLogger(getClass());
-
-    public static final int PROTOCOL_VERSION = 3;
+        implements Requester, Closeable {
 
+    public static final int MAX_SUPPORTED_VERSION = 3;
     public static final int DEFAULT_TIMEOUT = 30;
 
-    private volatile int timeout = DEFAULT_TIMEOUT;
+    /** Logger */
+    protected final Logger log = LoggerFactory.getLogger(getClass());
 
-    private final Subsystem sub;
-    private final PacketReader reader;
-    private final OutputStream out;
+    protected volatile int timeout = DEFAULT_TIMEOUT;
 
-    private long reqID;
-    private int negotiatedVersion;
-    private final Map<String, String> serverExtensions = new HashMap<String, String>();
+    protected final Subsystem sub;
+    protected final PacketReader reader;
+    protected final OutputStream out;
+
+    protected long reqID;
+    protected int operativeVersion;
+    protected final Map<String, String> serverExtensions = new HashMap<String, String>();
 
     public SFTPEngine(SessionFactory ssh)
             throws SSHException {
         sub = ssh.startSession().startSubsystem("sftp");
         out = sub.getOutputStream();
-        reader = new PacketReader(sub.getInputStream());
-    }
-
-    public Subsystem getSubsystem() {
-        return sub;
+        reader = new PacketReader(this);
     }
 
     public SFTPEngine init()
             throws IOException {
-        transmit(new SFTPPacket<Request>(PacketType.INIT).putInt(PROTOCOL_VERSION));
+        transmit(new SFTPPacket<Request>(PacketType.INIT).putInt(MAX_SUPPORTED_VERSION));
 
         final SFTPPacket<Response> response = reader.readPacket();
 
@@ -70,10 +66,10 @@ public class SFTPEngine
         if (type != PacketType.VERSION)
             throw new SFTPException("Expected INIT packet, received: " + type);
 
-        negotiatedVersion = response.readInt();
-        log.info("Client version {}, server version {}", PROTOCOL_VERSION, negotiatedVersion);
-        if (negotiatedVersion < PROTOCOL_VERSION)
-            throw new SFTPException("Server reported protocol version: " + negotiatedVersion);
+        operativeVersion = response.readInt();
+        log.info("Server version {}", operativeVersion);
+        if (MAX_SUPPORTED_VERSION < operativeVersion)
+            throw new SFTPException("Server reported incompatible protocol version: " + operativeVersion);
 
         while (response.available() > 0)
             serverExtensions.put(response.readString(), response.readString());
@@ -83,14 +79,24 @@ public class SFTPEngine
         return this;
     }
 
-    public int getOperativeProtocolVersion() {
-        return negotiatedVersion;
+    public Subsystem getSubsystem() {
+        return sub;
     }
 
+    public int getOperativeProtocolVersion() {
+        return operativeVersion;
+    }
+
+    public Request newExtendedRequest(String reqName) {
+        return newRequest(PacketType.EXTENDED).putString(reqName);
+    }
+
+    @Override
     public synchronized Request newRequest(PacketType type) {
         return new Request(type, reqID = reqID + 1 & 0xffffffffL);
     }
 
+    @Override
     public Response doRequest(Request req)
             throws IOException {
         reader.expectResponseTo(req);
@@ -99,20 +105,8 @@ public class SFTPEngine
         return req.getResponseFuture().get(timeout, TimeUnit.SECONDS);
     }
 
-    private synchronized void transmit(SFTPPacket<Request> payload)
-            throws IOException {
-        final int len = payload.available();
-        out.write((len >>> 24) & 0xff);
-        out.write((len >>> 16) & 0xff);
-        out.write((len >>> 8) & 0xff);
-        out.write(len & 0xff);
-        out.write(payload.array(), payload.rpos(), len);
-        out.flush();
-    }
-
     public RemoteFile open(String path, Set<OpenMode> modes, FileAttributes fa)
             throws IOException {
-
         final String handle = doRequest(
                 newRequest(PacketType.OPEN).putString(path).putInt(OpenMode.toMask(modes)).putFileAttributes(fa)
         ).ensurePacketTypeIs(PacketType.HANDLE).readString();
@@ -121,7 +115,7 @@ public class SFTPEngine
 
     public RemoteFile open(String filename, Set<OpenMode> modes)
             throws IOException {
-        return open(filename, modes, new FileAttributes());
+        return open(filename, modes, FileAttributes.EMPTY);
     }
 
     public RemoteFile open(String filename)
@@ -146,6 +140,8 @@ public class SFTPEngine
 
     public String readLink(String path)
             throws IOException {
+        if (operativeVersion < 3)
+            throw new SFTPException("READLINK is not supported in SFTPv" + operativeVersion);
         return readSingleName(
                 doRequest(
                         newRequest(PacketType.READLINK).putString(path)
@@ -154,18 +150,18 @@ public class SFTPEngine
 
     public void makeDir(String path, FileAttributes attrs)
             throws IOException {
-        doRequest(
-                newRequest(PacketType.MKDIR).putString(path).putFileAttributes(attrs)
-        ).ensureStatusPacketIsOK();
+        doRequest(newRequest(PacketType.MKDIR).putString(path).putFileAttributes(attrs)).ensureStatusPacketIsOK();
     }
 
     public void makeDir(String path)
             throws IOException {
-        makeDir(path, new FileAttributes());
+        makeDir(path, FileAttributes.EMPTY);
     }
 
     public void symlink(String linkpath, String targetpath)
             throws IOException {
+        if (operativeVersion < 3)
+            throw new SFTPException("SYMLINK is not supported in SFTPv" + operativeVersion);
         doRequest(
                 newRequest(PacketType.SYMLINK).putString(linkpath).putString(targetpath)
         ).ensureStatusPacketIsOK();
@@ -185,13 +181,6 @@ public class SFTPEngine
         ).ensureStatusIs(Response.StatusCode.OK);
     }
 
-    private FileAttributes stat(PacketType pt, String path)
-            throws IOException {
-        return doRequest(newRequest(pt).putString(path))
-                .ensurePacketTypeIs(PacketType.ATTRS)
-                .readFileAttributes();
-    }
-
     public FileAttributes stat(String path)
             throws IOException {
         return stat(PacketType.STAT, path);
@@ -204,6 +193,8 @@ public class SFTPEngine
 
     public void rename(String oldPath, String newPath)
             throws IOException {
+        if (operativeVersion < 1)
+            throw new SFTPException("RENAME is not supported in SFTPv" + operativeVersion);
         doRequest(
                 newRequest(PacketType.RENAME).putString(oldPath).putString(newPath)
         ).ensureStatusPacketIsOK();
@@ -217,15 +208,6 @@ public class SFTPEngine
                 ));
     }
 
-    private static String readSingleName(Response res)
-            throws IOException {
-        res.ensurePacketTypeIs(PacketType.NAME);
-        if (res.readInt() == 1)
-            return res.readString();
-        else
-            throw new SFTPException("Unexpected data in " + res.getType() + " packet");
-    }
-
     public void setTimeout(int timeout) {
         this.timeout = timeout;
     }
@@ -234,4 +216,37 @@ public class SFTPEngine
         return timeout;
     }
 
+    @Override
+    public void close()
+            throws IOException {
+        sub.close();
+    }
+
+    protected FileAttributes stat(PacketType pt, String path)
+            throws IOException {
+        return doRequest(newRequest(pt).putString(path))
+                .ensurePacketTypeIs(PacketType.ATTRS)
+                .readFileAttributes();
+    }
+
+    protected static String readSingleName(Response res)
+            throws IOException {
+        res.ensurePacketTypeIs(PacketType.NAME);
+        if (res.readInt() == 1)
+            return res.readString();
+        else
+            throw new SFTPException("Unexpected data in " + res.getType() + " packet");
+    }
+
+    protected synchronized void transmit(SFTPPacket<Request> payload)
+            throws IOException {
+        final int len = payload.available();
+        out.write((len >>> 24) & 0xff);
+        out.write((len >>> 16) & 0xff);
+        out.write((len >>> 8) & 0xff);
+        out.write(len & 0xff);
+        out.write(payload.array(), payload.rpos(), len);
+        out.flush();
+    }
+
 }

src/main/java/net/schmizz/sshj/sftp/SFTPException.java

@@ -25,6 +25,7 @@ public class SFTPException
 
     public static final ExceptionChainer<SFTPException> chainer = new ExceptionChainer<SFTPException>() {
 
+        @Override
         public SFTPException chain(Throwable t) {
             if (t instanceof SFTPException)
                 return (SFTPException) t;
@@ -66,7 +67,6 @@ public class SFTPException
 
     public StatusCode getStatusCode() {
         return (sc == null) ? StatusCode.UNKNOWN : sc;
-
     }
 
     public SFTPException(StatusCode sc, String msg) {

src/main/java/net/schmizz/sshj/sftp/SFTPFileTransfer.java

@@ -20,6 +20,7 @@ import net.schmizz.sshj.sftp.Response.StatusCode;
 import net.schmizz.sshj.xfer.AbstractFileTransfer;
 import net.schmizz.sshj.xfer.FileTransfer;
 import net.schmizz.sshj.xfer.FileTransferUtil;
+import net.schmizz.sshj.xfer.TransferListener;
 
 import java.io.File;
 import java.io.FileFilter;
@@ -32,38 +33,42 @@ public class SFTPFileTransfer
         extends AbstractFileTransfer
         implements FileTransfer {
 
-    private final SFTPEngine sftp;
+    private final SFTPEngine engine;
     private final PathHelper pathHelper;
 
     private volatile FileFilter uploadFilter = defaultLocalFilter;
     private volatile RemoteResourceFilter downloadFilter = defaultRemoteFilter;
 
     private static final FileFilter defaultLocalFilter = new FileFilter() {
+        @Override
         public boolean accept(File pathName) {
             return true;
         }
     };
 
     private static final RemoteResourceFilter defaultRemoteFilter = new RemoteResourceFilter() {
+        @Override
         public boolean accept(RemoteResourceInfo resource) {
             return true;
         }
     };
 
-    public SFTPFileTransfer(SFTPEngine sftp) {
-        this.sftp = sftp;
-        this.pathHelper = new PathHelper(sftp);
+    public SFTPFileTransfer(SFTPEngine engine) {
+        this.engine = engine;
+        this.pathHelper = new PathHelper(engine);
     }
 
+    @Override
     public void upload(String source, String dest)
             throws IOException {
         new Uploader().upload(new File(source), dest);
     }
 
+    @Override
     public void download(String source, String dest)
             throws IOException {
         final PathComponents pathComponents = pathHelper.getComponents(source);
-        final FileAttributes attributes = sftp.stat(source);
+        final FileAttributes attributes = engine.stat(source);
         new Downloader().download(new RemoteResourceInfo(pathComponents, attributes), new File(dest));
     }
 
@@ -85,7 +90,64 @@ public class SFTPFileTransfer
 
     private class Downloader {
 
-        private void setAttributes(final RemoteResourceInfo remote, final File local)
+        private final TransferListener listener = getTransferListener();
+
+        private void download(final RemoteResourceInfo remote, final File local)
+                throws IOException {
+            final File adjustedFile;
+            switch (remote.getAttributes().getType()) {
+                case DIRECTORY:
+                    listener.startedDir(remote.getName());
+                    adjustedFile = downloadDir(remote, local);
+                    listener.finishedDir();
+                    break;
+                case UNKNOWN:
+                    log.warn("Server did not supply information about the type of file at `{}` " +
+                             "-- assuming it is a regular file!", remote.getPath());
+                case REGULAR:
+                    listener.startedFile(remote.getName(), remote.getAttributes().getSize());
+                    adjustedFile = downloadFile(remote, local);
+                    listener.finishedFile();
+                    break;
+                default:
+                    throw new IOException(remote + " is not a regular file or directory");
+            }
+            copyAttributes(remote, adjustedFile);
+
+        }
+
+        private File downloadDir(final RemoteResourceInfo remote, final File local)
+                throws IOException {
+            final File adjusted = FileTransferUtil.getTargetDirectory(local, remote.getName());
+            final RemoteDirectory rd = engine.openDir(remote.getPath());
+            try {
+                for (RemoteResourceInfo rri : rd.scan(getDownloadFilter()))
+                    download(rri, new File(adjusted.getPath(), rri.getName()));
+            } finally {
+                rd.close();
+            }
+            return adjusted;
+        }
+
+        private File downloadFile(final RemoteResourceInfo remote, final File local)
+                throws IOException {
+            final File adjusted = FileTransferUtil.getTargetFile(local, remote.getName());
+            final RemoteFile rf = engine.open(remote.getPath());
+            try {
+                final FileOutputStream fos = new FileOutputStream(adjusted);
+                try {
+                    StreamCopier.copy(rf.getInputStream(), fos, engine.getSubsystem()
+                            .getLocalMaxPacketSize(), false, listener);
+                } finally {
+                    fos.close();
+                }
+            } finally {
+                rf.close();
+            }
+            return adjusted;
+        }
+
+        private void copyAttributes(final RemoteResourceInfo remote, final File local)
                 throws IOException {
             final FileAttributes attrs = remote.getAttributes();
             getModeSetter().setPermissions(local, attrs.getMode().getPermissionsMask());
@@ -95,102 +157,65 @@ public class SFTPFileTransfer
             }
         }
 
-        private void downloadFile(final RemoteResourceInfo remote, final File local)
-                throws IOException {
-            final File adjusted = FileTransferUtil.getTargetFile(local, remote.getName());
-            setAttributes(remote, adjusted);
-            final RemoteFile rf = sftp.open(remote.getPath());
-            try {
-                final FileOutputStream fos = new FileOutputStream(adjusted);
-                try {
-                    StreamCopier.copy(rf.getInputStream(), fos, sftp.getSubsystem()
-                            .getLocalMaxPacketSize(), false);
-                } finally {
-                    fos.close();
-                }
-            } finally {
-                rf.close();
-            }
-        }
-
-        private void downloadDir(final RemoteResourceInfo remote, final File local)
-                throws IOException {
-            final File adjusted = FileTransferUtil.getTargetDirectory(local, remote.getName());
-            setAttributes(remote, adjusted);
-            final RemoteDirectory rd = sftp.openDir(remote.getPath());
-            try {
-                for (RemoteResourceInfo rri : rd.scan(getDownloadFilter()))
-                    download(rri, new File(adjusted.getPath(), rri.getName()));
-            } finally {
-                rd.close();
-            }
-        }
-
-        void download(final RemoteResourceInfo remote, final File local)
-                throws IOException {
-            log.info("Downloading [{}] to [{}]", remote, local);
-            switch (remote.getAttributes().getType()) {
-                case DIRECTORY:
-                    downloadDir(remote, local);
-                    break;
-                case UNKNOWN:
-                    log.warn("Server did not supply information about the type of file at `{}` -- assuming it is a regular file!");
-                case REGULAR:
-                    downloadFile(remote, local);
-                    break;
-                default:
-                    throw new IOException(remote + " is not a regular file or directory");
-            }
-        }
     }
 
     private class Uploader {
 
-        void upload(File local, String remote)
+        private final TransferListener listener = getTransferListener();
+
+        private void upload(File local, String remote)
                 throws IOException {
-            log.info("Uploading [{}] to [{}]", local, remote);
-            if (local.isDirectory())
-                uploadDir(local, remote);
-            else if (local.isFile())
-                uploadFile(local, remote);
-            else
+            final String adjustedPath;
+            if (local.isDirectory()) {
+                listener.startedDir(local.getName());
+                adjustedPath = uploadDir(local, remote);
+                listener.finishedDir();
+            } else if (local.isFile()) {
+                listener.startedFile(local.getName(), local.length());
+                adjustedPath = uploadFile(local, remote);
+                listener.finishedFile();
+            } else
                 throw new IOException(local + " is not a file or directory");
+            engine.setAttributes(adjustedPath, getAttributes(local));
         }
 
-        private void uploadDir(File local, String remote)
+        private String uploadDir(File local, String remote)
                 throws IOException {
             final String adjusted = prepareDir(local, remote);
             for (File f : local.listFiles(getUploadFilter()))
                 upload(f, adjusted);
+            return adjusted;
         }
 
-        private void uploadFile(File local, String remote)
+        private String uploadFile(File local, String remote)
                 throws IOException {
             final String adjusted = prepareFile(local, remote);
-            final RemoteFile rf = sftp.open(adjusted, EnumSet.of(OpenMode.WRITE, OpenMode.CREAT, OpenMode.TRUNC),
-                                            getAttributes(local));
+            final RemoteFile rf = engine.open(adjusted, EnumSet.of(OpenMode.WRITE,
+                                                                   OpenMode.CREAT,
+                                                                   OpenMode.TRUNC));
             try {
                 final FileInputStream fis = new FileInputStream(local);
                 try {
-                    StreamCopier.copy(fis, rf.getOutputStream(), sftp.getSubsystem().getRemoteMaxPacketSize()
-                                                                 - rf.getOutgoingPacketOverhead(), false);
+                    final int bufSize = engine.getSubsystem().getRemoteMaxPacketSize() - rf.getOutgoingPacketOverhead();
+                    StreamCopier.copy(fis, rf.getOutputStream(), bufSize, false, listener);
                 } finally {
                     fis.close();
                 }
             } finally {
                 rf.close();
             }
+            return adjusted;
         }
 
         private String prepareDir(File local, String remote)
                 throws IOException {
             final FileAttributes attrs;
             try {
-                attrs = sftp.stat(remote);
+                attrs = engine.stat(remote);
             } catch (SFTPException e) {
                 if (e.getStatusCode() == StatusCode.NO_SUCH_FILE) {
                     log.debug("probeDir: {} does not exist, creating", remote);
-                    sftp.makeDir(remote, getAttributes(local));
+                    engine.makeDir(remote);
                     return remote;
                 } else
                     throw e;
@@ -199,11 +224,6 @@ public class SFTPFileTransfer
             if (attrs.getMode().getType() == FileMode.Type.DIRECTORY)
                 if (pathHelper.getComponents(remote).getName().equals(local.getName())) {
                     log.debug("probeDir: {} already exists", remote);
-                    final FileAttributes localAttrs = getAttributes(local);
-                    if (attrs.getMode().getMask() != localAttrs.getMode().getMask()
-                        || (getModeGetter().preservesTimes()
-                            && (attrs.getAtime() != attrs.getAtime() || attrs.getMtime() != localAttrs.getMtime())))
-                        sftp.setAttributes(remote, localAttrs);
                     return remote;
                 } else {
                     log.debug("probeDir: {} already exists, path adjusted for {}", remote, local.getName());
@@ -217,7 +237,7 @@ public class SFTPFileTransfer
                 throws IOException {
             final FileAttributes attrs;
             try {
-                attrs = sftp.stat(remote);
+                attrs = engine.stat(remote);
             } catch (SFTPException e) {
                 if (e.getStatusCode() == StatusCode.NO_SUCH_FILE) {
                     log.debug("probeFile: {} does not exist", remote);
@@ -238,7 +258,6 @@ public class SFTPFileTransfer
         private FileAttributes getAttributes(File local)
                 throws IOException {
             final FileAttributes.Builder builder = new FileAttributes.Builder()
-                    .withType(local.isDirectory() ? FileMode.Type.DIRECTORY : FileMode.Type.REGULAR)
                     .withPermissions(getModeGetter().getPermissions(local));
             if (getModeGetter().preservesTimes())
                 builder.withAtimeMtime(getModeGetter().getLastAccessTime(local), getModeGetter().getLastModifiedTime(local));

src/main/java/net/schmizz/sshj/sftp/StatefulSFTPClient.java

@@ -15,8 +15,6 @@
  */
 package net.schmizz.sshj.sftp;
 
-import net.schmizz.sshj.connection.channel.direct.SessionFactory;
-
 import java.io.IOException;
 import java.util.List;
 import java.util.Set;
@@ -26,9 +24,9 @@ public class StatefulSFTPClient
 
     private String cwd;
 
-    public StatefulSFTPClient(SessionFactory ssh)
+    public StatefulSFTPClient(SFTPEngine engine)
             throws IOException {
-        super(ssh);
+        super(engine);
         this.cwd = getSFTPEngine().canonicalize(".");
         log.info("Start dir = " + cwd);
     }
@@ -37,8 +35,12 @@ public class StatefulSFTPClient
         return PathComponents.adjustForParent(cwd, path);
     }
 
-    public synchronized void cd(String dirname) {
+    public synchronized void cd(String dirname)
+            throws IOException {
         cwd = cwdify(dirname);
+        if (statExistence(cwd) == null) {
+            throw new SFTPException(cwd + ": does not exist");
+        }
         log.info("CWD = " + cwd);
     }
 
@@ -98,6 +100,18 @@ public class StatefulSFTPClient
         super.mkdir(cwdify(dirname));
     }
 
+    @Override
+    public void mkdirs(String path)
+            throws IOException {
+        super.mkdirs(cwdify(path));
+    }
+
+    @Override
+    public FileAttributes statExistence(String path)
+            throws IOException {
+        return super.statExistence(cwdify(path));
+    }
+
     @Override
     public void rename(String oldpath, String newpath)
             throws IOException {
@@ -167,7 +181,7 @@ public class StatefulSFTPClient
     @Override
     public void put(String source, String dest)
             throws IOException {
-        super.get(source, cwdify(dest));
+        super.put(source, cwdify(dest));
     }
 
 }

src/main/java/net/schmizz/sshj/signature/AbstractSignature.java

@@ -47,29 +47,32 @@ import java.security.SignatureException;
 public abstract class AbstractSignature
         implements Signature {
 
+    protected final String algorithm;
     protected java.security.Signature signature;
-    protected String algorithm;
 
     protected AbstractSignature(String algorithm) {
         this.algorithm = algorithm;
     }
 
-    public void init(PublicKey pubkey, PrivateKey prvkey) {
+    @Override
+    public void init(PublicKey publicKey, PrivateKey privateKey) {
         try {
             signature = SecurityUtils.getSignature(algorithm);
-            if (pubkey != null)
-                signature.initVerify(pubkey);
-            if (prvkey != null)
-                signature.initSign(prvkey);
+            if (publicKey != null)
+                signature.initVerify(publicKey);
+            if (privateKey != null)
+                signature.initSign(privateKey);
         } catch (GeneralSecurityException e) {
             throw new SSHRuntimeException(e);
         }
     }
 
+    @Override
     public void update(byte[] foo) {
         update(foo, 0, foo.length);
     }
 
+    @Override
     public void update(byte[] foo, int off, int len) {
         try {
             signature.update(foo, off, len);
@@ -81,19 +84,18 @@ public abstract class AbstractSignature
     protected byte[] extractSig(byte[] sig) {
         if (sig[0] == 0 && sig[1] == 0 && sig[2] == 0) {
             int i = 0;
-            int j;
-            j = sig[i++] << 24 & 0xff000000 //
-                | sig[i++] << 16 & 0x00ff0000 //
-                | sig[i++] << 8 & 0x0000ff00 //
-                | sig[i++] & 0x000000ff;
+            int j = sig[i++] << 24 & 0xff000000
+                    | sig[i++] << 16 & 0x00ff0000
+                    | sig[i++] << 8 & 0x0000ff00
+                    | sig[i++] & 0x000000ff;
             i += j;
-            j = sig[i++] << 24 & 0xff000000 //
-                | sig[i++] << 16 & 0x00ff0000 //
-                | sig[i++] << 8 & 0x0000ff00 //
+            j = sig[i++] << 24 & 0xff000000
+                | sig[i++] << 16 & 0x00ff0000
+                | sig[i++] << 8 & 0x0000ff00
                 | sig[i++] & 0x000000ff;
-            byte[] tmp = new byte[j];
-            System.arraycopy(sig, i, tmp, 0, j);
-            sig = tmp;
+            byte[] newSig = new byte[j];
+            System.arraycopy(sig, i, newSig, 0, j);
+            sig = newSig;
         }
         return sig;
     }

src/main/java/net/schmizz/sshj/signature/SignatureDSA.java

@@ -48,10 +48,12 @@ public class SignatureDSA
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Signature> {
 
+        @Override
         public Signature create() {
             return new SignatureDSA();
         }
 
+        @Override
         public String getName() {
             return KeyType.DSA.toString();
         }
@@ -62,6 +64,7 @@ public class SignatureDSA
         super("SHA1withDSA");
     }
 
+    @Override
     public byte[] sign() {
         byte[] sig;
         try {
@@ -72,15 +75,16 @@ public class SignatureDSA
 
         // sig is in ASN.1
         // SEQUENCE::={ r INTEGER, s INTEGER }
-        int len = 0;
-        int index = 3;
-        len = sig[index++] & 0xff;
-        byte[] r = new byte[len];
-        System.arraycopy(sig, index, r, 0, r.length);
-        index = index + len + 1;
-        len = sig[index++] & 0xff;
-        byte[] s = new byte[len];
-        System.arraycopy(sig, index, s, 0, s.length);
+
+        int rIndex = 3;
+        int rLen = sig[rIndex++] & 0xff;
+        byte[] r = new byte[rLen];
+        System.arraycopy(sig, rIndex, r, 0, r.length);
+
+        int sIndex = rIndex + rLen + 1;
+        int sLen = sig[sIndex++] & 0xff;
+        byte[] s = new byte[sLen];
+        System.arraycopy(sig, sIndex, s, 0, s.length);
 
         byte[] result = new byte[40];
 
@@ -91,6 +95,7 @@ public class SignatureDSA
                          result,
                          r.length > 20 ? 0 : 20 - r.length,
                          r.length > 20 ? 20 : r.length);
+
         System.arraycopy(s,
                          s.length > 20 ? 1 : 0,
                          result,
@@ -100,6 +105,7 @@ public class SignatureDSA
         return result;
     }
 
+    @Override
     public boolean verify(byte[] sig) {
         sig = extractSig(sig);
 

src/main/java/net/schmizz/sshj/signature/SignatureRSA.java

@@ -48,10 +48,12 @@ public class SignatureRSA
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Signature> {
 
+        @Override
         public Signature create() {
             return new SignatureRSA();
         }
 
+        @Override
         public String getName() {
             return KeyType.RSA.toString();
         }
@@ -62,6 +64,7 @@ public class SignatureRSA
         super("SHA1withRSA");
     }
 
+    @Override
     public byte[] sign() {
         try {
             return signature.sign();
@@ -70,6 +73,7 @@ public class SignatureRSA
         }
     }
 
+    @Override
     public boolean verify(byte[] sig) {
         sig = extractSig(sig);
         try {

src/main/java/net/schmizz/sshj/transport/Converter.java

@@ -74,7 +74,7 @@ abstract class Converter {
         this.mac = mac;
         this.compression = compression;
         if (compression != null)
-            compression.init(getCompressionType(), -1);
+            compression.init(getCompressionType());
         this.cipherSize = cipher.getIVSize();
     }
 
@@ -86,6 +86,6 @@ abstract class Converter {
         return compression != null && (authed || !compression.isDelayed());
     }
 
-    abstract Compression.Type getCompressionType();
+    abstract Compression.Mode getCompressionType();
 
 }

src/main/java/net/schmizz/sshj/transport/Decoder.java

@@ -199,8 +199,8 @@ final class Decoder
     }
 
     @Override
-    Compression.Type getCompressionType() {
-        return Compression.Type.Inflater;
+    Compression.Mode getCompressionType() {
+        return Compression.Mode.INFLATE;
     }
 
     int getMaxPacketLength() {

src/main/java/net/schmizz/sshj/transport/Encoder.java

@@ -160,9 +160,8 @@ final class Encoder
     }
 
     @Override
-    Compression.Type getCompressionType() {
-        return Compression.Type.Deflater;
+    Compression.Mode getCompressionType() {
+        return Compression.Mode.DEFLATE;
     }
 
-
 }

src/main/java/net/schmizz/sshj/transport/Heartbeater.java

@@ -50,8 +50,6 @@ final class Heartbeater
 
     private int interval;
 
-    private boolean started;
-
     Heartbeater(TransportImpl trans) {
         this.trans = trans;
         setName("heartbeater");
@@ -59,36 +57,36 @@ final class Heartbeater
 
     synchronized void setInterval(int interval) {
         this.interval = interval;
-        if (interval != 0) {
-            if (!started)
-                start();
-            notify();
-        }
+        if (interval > 0 && getState() == Thread.State.NEW)
+            start();
+        notify();
     }
 
     synchronized int getInterval() {
         return interval;
     }
 
+    synchronized private int getPositiveInterval()
+            throws InterruptedException {
+        while (interval <= 0)
+            wait();
+        return interval;
+    }
+
     @Override
     public void run() {
+        log.debug("Starting");
         try {
-            while (!Thread.currentThread().isInterrupted()) {
-                int hi;
-                synchronized (this) {
-                    while ((hi = interval) == 0)
-                        wait();
-                }
-                if (!started)
-                    started = true;
-                else if (trans.isRunning()) {
+            while (!isInterrupted()) {
+                final int hi = getPositiveInterval();
+                if (trans.isRunning()) {
                     log.info("Sending heartbeat since {} seconds elapsed", hi);
                     trans.write(new SSHPacket(Message.IGNORE));
                 }
                 Thread.sleep(hi * 1000);
             }
         } catch (Exception e) {
-            if (Thread.currentThread().isInterrupted()) {
+            if (isInterrupted()) {
                 // We are meant to shut up and draw to a close if interrupted
             } else
                 trans.die(e);
@@ -96,4 +94,5 @@ final class Heartbeater
 
         log.debug("Stopping");
     }
+
 }

src/main/java/net/schmizz/sshj/transport/KeyExchanger.java

@@ -47,6 +47,7 @@ import net.schmizz.sshj.transport.verification.HostKeyVerifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.security.GeneralSecurityException;
 import java.security.PublicKey;
 import java.util.Arrays;
 import java.util.LinkedList;
@@ -91,8 +92,7 @@ final class KeyExchanger
     private Proposal clientProposal;
     private NegotiatedAlgorithms negotiatedAlgs;
 
-    private final Event<TransportException> kexInitSent = new Event<TransportException>("kexinit sent",
-                                                                                        TransportException.chainer);
+    private final Event<TransportException> kexInitSent = new Event<TransportException>("kexinit sent", TransportException.chainer);
 
     private final Event<TransportException> done;
 
@@ -228,8 +228,12 @@ final class KeyExchanger
         log.debug("Negotiated algorithms: {}", negotiatedAlgs);
         kex = Factory.Named.Util.create(transport.getConfig().getKeyExchangeFactories(), negotiatedAlgs
                 .getKeyExchangeAlgorithm());
-        kex.init(transport, transport.getServerID().getBytes(), transport.getClientID().getBytes(), buf
-                .getCompactData(), clientProposal.getPacket().getCompactData());
+        try {
+            kex.init(transport, transport.getServerID().getBytes(), transport.getClientID().getBytes(), buf
+                    .getCompactData(), clientProposal.getPacket().getCompactData());
+        } catch (GeneralSecurityException e) {
+            throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED, e);
+        }
     }
 
     /**
@@ -326,6 +330,7 @@ final class KeyExchanger
         transport.getDecoder().setAlgorithms(cipher_S2C, mac_S2C, compression_S2C);
     }
 
+    @Override
     public void handle(Message msg, SSHPacket buf)
             throws TransportException {
         switch (expected) {
@@ -347,10 +352,14 @@ final class KeyExchanger
             case FOLLOWUP:
                 ensureKexOngoing();
                 log.info("Received kex followup data");
-                if (kex.next(msg, buf)) {
-                    verifyHost(kex.getHostKey());
-                    sendNewKeys();
-                    expected = Expected.NEWKEYS;
+                try {
+                    if (kex.next(msg, buf)) {
+                        verifyHost(kex.getHostKey());
+                        sendNewKeys();
+                        expected = Expected.NEWKEYS;
+                    }
+                } catch (GeneralSecurityException e) {
+                    throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED, e);
                 }
                 break;
 
@@ -369,6 +378,7 @@ final class KeyExchanger
         }
     }
 
+    @Override
     public void notifyError(SSHException error) {
         log.debug("Got notified of {}", error.toString());
         FutureUtils.alertAll(error, kexInitSent, done);

src/main/java/net/schmizz/sshj/transport/Reader.java

@@ -41,22 +41,20 @@ import org.slf4j.LoggerFactory;
 
 import java.io.InputStream;
 
-final class Reader
+public final class Reader
         extends Thread {
 
     private final Logger log = LoggerFactory.getLogger(getClass());
 
     private final TransportImpl trans;
 
-    Reader(TransportImpl trans) {
+    public Reader(TransportImpl trans) {
         this.trans = trans;
         setName("reader");
     }
 
     @Override
     public void run() {
-        final Thread curThread = Thread.currentThread();
-
         try {
 
             final Decoder decoder = trans.getDecoder();
@@ -66,7 +64,7 @@ final class Reader
 
             int needed = 1;
 
-            while (!curThread.isInterrupted()) {
+            while (!isInterrupted()) {
                 int read = inp.read(recvbuf, 0, needed);
                 if (read == -1)
                     throw new TransportException("Broken transport; encountered EOF");
@@ -75,7 +73,7 @@ final class Reader
             }
 
         } catch (Exception e) {
-            if (curThread.isInterrupted()) {
+            if (isInterrupted()) {
                 // We are meant to shut up and draw to a close if interrupted
             } else
                 trans.die(e);

src/main/java/net/schmizz/sshj/transport/TransportException.java

@@ -25,6 +25,7 @@ public class TransportException
 
     /** @see ExceptionChainer */
     public static final ExceptionChainer<TransportException> chainer = new ExceptionChainer<TransportException>() {
+        @Override
         public TransportException chain(Throwable t) {
             if (t instanceof TransportException)
                 return (TransportException) t;

src/main/java/net/schmizz/sshj/transport/TransportImpl.java

@@ -133,6 +133,7 @@ public final class TransportImpl
         clientID = "SSH-2.0-" + config.getVersion();
     }
 
+    @Override
     public void init(String remoteHost, int remotePort, InputStream in, OutputStream out)
             throws TransportException {
         connInfo = new ConnInfo(remoteHost, remotePort, in, out);
@@ -214,10 +215,12 @@ public final class TransportImpl
         return ident;
     }
 
+    @Override
     public void addHostKeyVerifier(HostKeyVerifier hkv) {
         kexer.addHostKeyVerifier(hkv);
     }
 
+    @Override
     public void doKex()
             throws TransportException {
         kexer.startKex(true);
@@ -227,50 +230,62 @@ public final class TransportImpl
         return kexer.isKexDone();
     }
 
+    @Override
     public int getTimeout() {
         return timeout;
     }
 
+    @Override
     public void setTimeout(int timeout) {
         this.timeout = timeout;
     }
 
+    @Override
     public int getHeartbeatInterval() {
         return heartbeater.getInterval();
     }
 
+    @Override
     public void setHeartbeatInterval(int interval) {
         heartbeater.setInterval(interval);
     }
 
+    @Override
     public String getRemoteHost() {
         return connInfo.host;
     }
 
+    @Override
     public int getRemotePort() {
         return connInfo.port;
     }
 
+    @Override
     public String getClientVersion() {
         return clientID.substring(8);
     }
 
+    @Override
     public Config getConfig() {
         return config;
     }
 
+    @Override
     public String getServerVersion() {
         return serverID == null ? serverID : serverID.substring(8);
     }
 
+    @Override
     public byte[] getSessionID() {
         return kexer.getSessionID();
     }
 
+    @Override
     public synchronized Service getService() {
         return service;
     }
 
+    @Override
     public synchronized void setService(Service service) {
         if (service == null)
             service = nullService;
@@ -279,6 +294,7 @@ public final class TransportImpl
         this.service = service;
     }
 
+    @Override
     public void reqService(Service service)
             throws TransportException {
         serviceAccept.lock();
@@ -305,16 +321,19 @@ public final class TransportImpl
         write(new SSHPacket(Message.SERVICE_REQUEST).putString(serviceName));
     }
 
+    @Override
     public void setAuthenticated() {
         this.authed = true;
         encoder.setAuthenticated();
         decoder.setAuthenticated();
     }
 
+    @Override
     public boolean isAuthenticated() {
         return authed;
     }
 
+    @Override
     public long sendUnimplemented()
             throws TransportException {
         final long seq = decoder.getSequenceNumber();
@@ -322,23 +341,28 @@ public final class TransportImpl
         return write(new SSHPacket(Message.UNIMPLEMENTED).putInt(seq));
     }
 
+    @Override
     public void join()
             throws TransportException {
         close.await();
     }
 
+    @Override
     public boolean isRunning() {
         return reader.isAlive() && !close.isSet();
     }
 
+    @Override
     public void disconnect() {
         disconnect(DisconnectReason.BY_APPLICATION);
     }
 
+    @Override
     public void disconnect(DisconnectReason reason) {
         disconnect(reason, "");
     }
 
+    @Override
     public void disconnect(DisconnectReason reason, String message) {
         close.lock(); // CAS type operation on close
         try {
@@ -357,6 +381,7 @@ public final class TransportImpl
         }
     }
 
+    @Override
     public long write(SSHPacket payload)
             throws TransportException {
         writeLock.lock();
@@ -396,8 +421,8 @@ public final class TransportImpl
                     .putInt(reason.toInt())
                     .putString(message)
                     .putString(""));
-        } catch (IOException logged) {
-            log.warn("Error writing packet: {}", logged);
+        } catch (IOException worthless) {
+            log.debug("Error writing packet: {}", worthless.toString());
         }
     }
 
@@ -416,6 +441,7 @@ public final class TransportImpl
      *
      * @throws SSHException if an error occurs during handling (unrecoverable)
      */
+    @Override
     public void handle(Message msg, SSHPacket buf)
             throws SSHException {
         this.msg = msg;

src/main/java/net/schmizz/sshj/transport/cipher/AES128CBC.java

@@ -42,10 +42,12 @@ public class AES128CBC
     /** Named factory for AES128CBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES128CBC();
         }
 
+        @Override
         public String getName() {
             return "aes128-cbc";
         }

src/main/java/net/schmizz/sshj/transport/cipher/AES128CTR.java

@@ -42,10 +42,12 @@ public class AES128CTR
     /** Named factory for AES128CBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES128CTR();
         }
 
+        @Override
         public String getName() {
             return "aes128-ctr";
         }

src/main/java/net/schmizz/sshj/transport/cipher/AES192CBC.java

@@ -42,10 +42,12 @@ public class AES192CBC
     /** Named factory for AES192CBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES192CBC();
         }
 
+        @Override
         public String getName() {
             return "aes192-cbc";
         }

src/main/java/net/schmizz/sshj/transport/cipher/AES192CTR.java

@@ -42,10 +42,12 @@ public class AES192CTR
     /** Named factory for AES192CTR Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES192CTR();
         }
 
+        @Override
         public String getName() {
             return "aes192-ctr";
         }

src/main/java/net/schmizz/sshj/transport/cipher/AES256CBC.java

@@ -42,10 +42,12 @@ public class AES256CBC
     /** Named factory for AES256CBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES256CBC();
         }
 
+        @Override
         public String getName() {
             return "aes256-cbc";
         }

src/main/java/net/schmizz/sshj/transport/cipher/AES256CTR.java

@@ -42,10 +42,12 @@ public class AES256CTR
     /** Named factory for AES256CBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new AES256CTR();
         }
 
+        @Override
         public String getName() {
             return "aes256-ctr";
         }

src/main/java/net/schmizz/sshj/transport/cipher/BaseCipher.java

@@ -70,14 +70,17 @@ public class BaseCipher
         this.transformation = transformation;
     }
 
+    @Override
     public int getBlockSize() {
         return bsize;
     }
 
+    @Override
     public int getIVSize() {
         return ivsize;
     }
 
+    @Override
     public void init(Mode mode, byte[] key, byte[] iv) {
         key = BaseCipher.resize(key, bsize);
         iv = BaseCipher.resize(iv, ivsize);
@@ -91,6 +94,7 @@ public class BaseCipher
         }
     }
 
+    @Override
     public void update(byte[] input, int inputOffset, int inputLen) {
         try {
             cipher.update(input, inputOffset, inputLen, input, inputOffset);

src/main/java/net/schmizz/sshj/transport/cipher/BlowfishCBC.java

@@ -42,10 +42,12 @@ public class BlowfishCBC
     /** Named factory for BlowfishCBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new BlowfishCBC();
         }
 
+        @Override
         public String getName() {
             return "blowfish-cbc";
         }

src/main/java/net/schmizz/sshj/transport/cipher/NoneCipher.java

@@ -42,26 +42,32 @@ public class NoneCipher
     /** Named factory for the no-op Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new NoneCipher();
         }
 
+        @Override
         public String getName() {
             return "none";
         }
     }
 
+    @Override
     public int getBlockSize() {
         return 8;
     }
 
+    @Override
     public int getIVSize() {
         return 8;
     }
 
+    @Override
     public void init(Mode mode, byte[] bytes, byte[] bytes1) {
     }
 
+    @Override
     public void update(byte[] input, int inputOffset, int inputLen) {
     }
 

src/main/java/net/schmizz/sshj/transport/cipher/TripleDESCBC.java

@@ -42,10 +42,12 @@ public class TripleDESCBC
     /** Named factory for TripleDESCBC Cipher */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Cipher> {
+        @Override
         public Cipher create() {
             return new TripleDESCBC();
         }
 
+        @Override
         public String getName() {
             return "3des-cbc";
         }

src/main/java/net/schmizz/sshj/transport/compression/Compression.java

@@ -35,34 +35,26 @@
  */
 package net.schmizz.sshj.transport.compression;
 
-import net.schmizz.sshj.common.SSHPacket;
+import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.transport.TransportException;
 
 /** Interface used to compress the stream of data between the SSH server and clients. */
 public interface Compression {
 
     /** Enum identifying if this object will be used to compress or uncompress data. */
-    enum Type {
-        Inflater,
-        Deflater
+    enum Mode {
+        INFLATE,
+        DEFLATE
     }
 
-    /**
-     * Compress the given buffer in place.
-     *
-     * @param buffer the buffer containing the data to compress s
-     */
-    void compress(SSHPacket buffer);
-
     /**
      * Initialize this object to either compress or uncompress data. This method must be called prior to any calls to
      * either <code>compress</code> or <code>uncompress</code>. Once the object has been initialized, only one of
      * <code>compress</code> or <code>uncompress</code> method can be called.
      *
-     * @param type
-     * @param level
+     * @param mode
      */
-    void init(Type type, int level);
+    void init(Mode mode);
 
     /**
      * Delayed compression is an Open-SSH specific feature which informs both the client and server to not compress data
@@ -72,13 +64,22 @@ public interface Compression {
      */
     boolean isDelayed();
 
+    /**
+     * Compress the given buffer in place.
+     *
+     * @param buffer the buffer containing the data to compress s
+     */
+    void compress(Buffer buffer);
+
     /**
      * Uncompress the data in a buffer into another buffer.
      *
      * @param from the buffer containing the data to uncompress
      * @param to   the buffer receiving the uncompressed data
+     *
+     * @throws TransportException
      */
-    void uncompress(SSHPacket from, SSHPacket to)
+    void uncompress(Buffer from, Buffer to)
             throws TransportException;
 
 }

src/main/java/net/schmizz/sshj/transport/compression/DelayedZlibCompression.java

@@ -46,10 +46,12 @@ public class DelayedZlibCompression
     /** Named factory for the ZLib Delayed Compression. */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Compression> {
+        @Override
         public Compression create() {
             return new DelayedZlibCompression();
         }
 
+        @Override
         public String getName() {
             return "zlib@openssh.com";
         }

src/main/java/net/schmizz/sshj/transport/compression/NoneCompression.java

@@ -42,10 +42,12 @@ public abstract class NoneCompression
     /** Named factory for the no-op <code>Compression</code> */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Compression> {
+        @Override
         public Compression create() {
             return null;
         }
 
+        @Override
         public String getName() {
             return "none";
         }

src/main/java/net/schmizz/sshj/transport/compression/ZlibCompression.java

@@ -37,8 +37,8 @@ package net.schmizz.sshj.transport.compression;
 
 import com.jcraft.jzlib.JZlib;
 import com.jcraft.jzlib.ZStream;
+import net.schmizz.sshj.common.Buffer;
 import net.schmizz.sshj.common.DisconnectReason;
-import net.schmizz.sshj.common.SSHPacket;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.transport.TransportException;
 
@@ -49,73 +49,80 @@ public class ZlibCompression
     /** Named factory for the ZLib Compression. */
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Compression> {
+        @Override
         public Compression create() {
             return new ZlibCompression();
         }
 
+        @Override
         public String getName() {
             return "zlib";
         }
     }
 
-    static private final int BUF_SIZE = 4096;
+    private static final int BUF_SIZE = 4096;
+
+    private final byte[] tempBuf = new byte[BUF_SIZE];
 
     private ZStream stream;
-    private final byte[] tmpbuf = new byte[BUF_SIZE];
 
-    /** Create a new instance of a ZLib base compression */
-    public ZlibCompression() {
+    @Override
+    public void init(Mode mode) {
+        stream = new ZStream();
+        switch (mode) {
+            case DEFLATE:
+                stream.deflateInit(JZlib.Z_DEFAULT_COMPRESSION);
+                break;
+            case INFLATE:
+                stream.inflateInit();
+                break;
+            default:
+                assert false;
+        }
     }
 
-    public void compress(SSHPacket buffer) {
+    @Override
+    public boolean isDelayed() {
+        return false;
+    }
+
+    @Override
+    public void compress(Buffer buffer) {
         stream.next_in = buffer.array();
         stream.next_in_index = buffer.rpos();
         stream.avail_in = buffer.available();
         buffer.wpos(buffer.rpos());
         do {
-            stream.next_out = tmpbuf;
+            stream.next_out = tempBuf;
             stream.next_out_index = 0;
             stream.avail_out = BUF_SIZE;
-            int status = stream.deflate(JZlib.Z_PARTIAL_FLUSH);
-            switch (status) {
-                case JZlib.Z_OK:
-                    buffer.putRawBytes(tmpbuf, 0, BUF_SIZE - stream.avail_out);
-                    break;
-                default:
-                    throw new SSHRuntimeException("compress: deflate returned " + status);
+            final int status = stream.deflate(JZlib.Z_PARTIAL_FLUSH);
+            if (status == JZlib.Z_OK) {
+                buffer.putRawBytes(tempBuf, 0, BUF_SIZE - stream.avail_out);
+            } else {
+                throw new SSHRuntimeException("compress: deflate returned " + status);
             }
         } while (stream.avail_out == 0);
     }
 
-    public void init(Type type, int level) {
-        stream = new ZStream();
-        if (type == Type.Deflater)
-            stream.deflateInit(level);
-        else
-            stream.inflateInit();
-    }
 
-    public boolean isDelayed() {
-        return false;
-    }
-
-    public void uncompress(SSHPacket from, SSHPacket to)
+    @Override
+    public void uncompress(Buffer from, Buffer to)
             throws TransportException {
         stream.next_in = from.array();
         stream.next_in_index = from.rpos();
         stream.avail_in = from.available();
-
         while (true) {
-            stream.next_out = tmpbuf;
+            stream.next_out = tempBuf;
             stream.next_out_index = 0;
             stream.avail_out = BUF_SIZE;
-            int status = stream.inflate(JZlib.Z_PARTIAL_FLUSH);
+            final int status = stream.inflate(JZlib.Z_PARTIAL_FLUSH);
             switch (status) {
                 case JZlib.Z_OK:
-                    to.putRawBytes(tmpbuf, 0, BUF_SIZE - stream.avail_out);
+                    to.putRawBytes(tempBuf, 0, BUF_SIZE - stream.avail_out);
                     break;
                 case JZlib.Z_BUF_ERROR:
-                    return; // wtf.. but this works *head spins*
+                    return;
                 default:
                     throw new TransportException(DisconnectReason.COMPRESSION_ERROR, "uncompress: inflate returned "
                                                                                      + status);

src/main/java/net/schmizz/sshj/transport/digest/BaseDigest.java

@@ -61,14 +61,17 @@ public class BaseDigest
         this.bsize = bsize;
     }
 
+    @Override
     public byte[] digest() {
         return md.digest();
     }
 
+    @Override
     public int getBlockSize() {
         return bsize;
     }
 
+    @Override
     public void init() {
         try {
             md = SecurityUtils.getMessageDigest(algorithm);
@@ -77,10 +80,12 @@ public class BaseDigest
         }
     }
 
+    @Override
     public void update(byte[] foo) {
         update(foo, 0, foo.length);
     }
 
+    @Override
     public void update(byte[] foo, int start, int len) {
         md.update(foo, start, len);
     }

src/main/java/net/schmizz/sshj/transport/digest/MD5.java

@@ -43,10 +43,12 @@ public class MD5
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Digest> {
 
+        @Override
         public Digest create() {
             return new MD5();
         }
 
+        @Override
         public String getName() {
             return "md5";
         }

src/main/java/net/schmizz/sshj/transport/digest/SHA1.java

@@ -43,10 +43,12 @@ public class SHA1
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<Digest> {
 
+        @Override
         public Digest create() {
             return new SHA1();
         }
 
+        @Override
         public String getName() {
             return "sha1";
         }

src/main/java/net/schmizz/sshj/transport/kex/AbstractDHG.java

@@ -50,6 +50,8 @@ import net.schmizz.sshj.transport.digest.SHA1;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.math.BigInteger;
+import java.security.GeneralSecurityException;
 import java.security.PublicKey;
 
 /**
@@ -72,29 +74,33 @@ public abstract class AbstractDHG
     private byte[] I_C;
 
     private byte[] e;
-    private byte[] f;
     private byte[] K;
     private byte[] H;
     private PublicKey hostKey;
 
+    @Override
     public byte[] getH() {
         return ByteArrayUtils.copyOf(H);
     }
 
-    public Digest getHash() {
-        return sha;
-    }
-
-    public PublicKey getHostKey() {
-        return hostKey;
-    }
-
+    @Override
     public byte[] getK() {
         return ByteArrayUtils.copyOf(K);
     }
 
+    @Override
+    public Digest getHash() {
+        return sha;
+    }
+
+    @Override
+    public PublicKey getHostKey() {
+        return hostKey;
+    }
+
+    @Override
     public void init(Transport trans, byte[] V_S, byte[] V_C, byte[] I_S, byte[] I_C)
-            throws TransportException {
+            throws GeneralSecurityException, TransportException {
         this.trans = trans;
         this.V_S = ByteArrayUtils.copyOf(V_S);
         this.V_C = ByteArrayUtils.copyOf(V_C);
@@ -108,29 +114,30 @@ public abstract class AbstractDHG
         trans.write(new SSHPacket(Message.KEXDH_INIT).putMPInt(e));
     }
 
+    @Override
     public boolean next(Message msg, SSHPacket packet)
-            throws TransportException {
+            throws GeneralSecurityException, TransportException {
         if (msg != Message.KEXDH_31)
-            throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED, "Unxpected packet: " + msg);
+            throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED, "Unexpected packet: " + msg);
 
         log.info("Received SSH_MSG_KEXDH_REPLY");
         final byte[] K_S = packet.readBytes();
-        f = packet.readMPIntAsBytes();
+        final byte[] f = packet.readMPIntAsBytes();
         final byte[] sig = packet.readBytes(); // signature sent by server
-        dh.setF(f);
+        dh.setF(new BigInteger(f));
         K = dh.getK();
 
         hostKey = new Buffer.PlainBuffer(K_S).readPublicKey();
 
-        final Buffer.PlainBuffer buf = new Buffer.PlainBuffer() // our hash
-                .putString(V_C) // 
-                .putString(V_S) // 
-                .putString(I_C) //
-                .putString(I_S) //
-                .putString(K_S) //
-                .putMPInt(e) //
-                .putMPInt(f) //
-                .putMPInt(K); //
+        final Buffer.PlainBuffer buf = new Buffer.PlainBuffer()
+                .putString(V_C)
+                .putString(V_S)
+                .putString(I_C)
+                .putString(I_S)
+                .putString(K_S)
+                .putMPInt(e)
+                .putMPInt(f)
+                .putMPInt(K);
         sha.update(buf.array(), 0, buf.available());
         H = sha.digest();
 
@@ -139,7 +146,8 @@ public abstract class AbstractDHG
         signature.init(hostKey, null);
         signature.update(H, 0, H.length);
         if (!signature.verify(sig))
-            throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED, "KeyExchange signature verification failed");
+            throw new TransportException(DisconnectReason.KEY_EXCHANGE_FAILED,
+                                         "KeyExchange signature verification failed");
         return true;
     }
 

src/main/java/net/schmizz/sshj/transport/kex/DH.java

@@ -35,7 +35,6 @@
  */
 package net.schmizz.sshj.transport.kex;
 
-import net.schmizz.sshj.common.ByteArrayUtils;
 import net.schmizz.sshj.common.SSHRuntimeException;
 import net.schmizz.sshj.common.SecurityUtils;
 
@@ -55,79 +54,53 @@ public class DH {
     private BigInteger p;
     private BigInteger g;
     private BigInteger e; // my public key
-    private byte[] e_array;
     private BigInteger f; // your public key
     private BigInteger K; // shared secret key
-    private byte[] K_array;
-    private final KeyPairGenerator myKpairGen;
-    private final KeyAgreement myKeyAgree;
+    private final KeyPairGenerator generator;
+    private final KeyAgreement agreement;
 
     public DH() {
         try {
-            myKpairGen = SecurityUtils.getKeyPairGenerator("DH");
-            myKeyAgree = SecurityUtils.getKeyAgreement("DH");
+            generator = SecurityUtils.getKeyPairGenerator("DH");
+            agreement = SecurityUtils.getKeyAgreement("DH");
         } catch (GeneralSecurityException e) {
             throw new SSHRuntimeException(e);
         }
-
     }
 
-    public byte[] getE() {
-        if (e == null) {
-            DHParameterSpec dhSkipParamSpec = new DHParameterSpec(p, g);
-            KeyPair myKpair;
-            try {
-                myKpairGen.initialize(dhSkipParamSpec);
-                myKpair = myKpairGen.generateKeyPair();
-                myKeyAgree.init(myKpair.getPrivate());
-            } catch (GeneralSecurityException e) {
-                throw new SSHRuntimeException(e);
-            }
-            e = ((javax.crypto.interfaces.DHPublicKey) myKpair.getPublic()).getY();
-            e_array = e.toByteArray();
-        }
-        return ByteArrayUtils.copyOf(e_array);
-    }
-
-    public byte[] getK() {
-        if (K == null) {
-            try {
-                KeyFactory myKeyFac = SecurityUtils.getKeyFactory("DH");
-                DHPublicKeySpec keySpec = new DHPublicKeySpec(f, p, g);
-                PublicKey yourPubKey = myKeyFac.generatePublic(keySpec);
-                myKeyAgree.doPhase(yourPubKey, true);
-            } catch (GeneralSecurityException e) {
-                throw new SSHRuntimeException(e);
-            }
-            byte[] mySharedSecret = myKeyAgree.generateSecret();
-            K = new BigInteger(mySharedSecret);
-            K_array = mySharedSecret;
-        }
-        return ByteArrayUtils.copyOf(K_array);
-    }
-
-    public void setF(byte[] f) {
-        setF(new BigInteger(f));
-    }
-
-    public void setG(byte[] g) {
-        setG(new BigInteger(g));
-    }
-
-    public void setP(byte[] p) {
-        setP(new BigInteger(p));
-    }
-
-    void setF(BigInteger f) {
+    public void setF(BigInteger f) {
         this.f = f;
     }
 
-    void setG(BigInteger g) {
+    public void setG(BigInteger g) {
         this.g = g;
     }
 
-    void setP(BigInteger p) {
+    public void setP(BigInteger p) {
         this.p = p;
     }
 
+    public byte[] getE()
+            throws GeneralSecurityException {
+        if (e == null) {
+            generator.initialize(new DHParameterSpec(p, g));
+            final KeyPair kp = generator.generateKeyPair();
+            agreement.init(kp.getPrivate());
+            e = ((javax.crypto.interfaces.DHPublicKey) kp.getPublic()).getY();
+        }
+        return e.toByteArray();
+    }
+
+    public byte[] getK()
+            throws GeneralSecurityException {
+        if (K == null) {
+            final KeyFactory keyFactory = SecurityUtils.getKeyFactory("DH");
+            final DHPublicKeySpec keySpec = new DHPublicKeySpec(f, p, g);
+            final PublicKey yourPubKey = keyFactory.generatePublic(keySpec);
+            agreement.doPhase(yourPubKey, true);
+            K = new BigInteger(agreement.generateSecret());
+        }
+        return K.toByteArray();
+    }
+
 }

src/main/java/net/schmizz/sshj/transport/kex/DHG1.java

@@ -47,10 +47,12 @@ public class DHG1
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<KeyExchange> {
 
+        @Override
         public KeyExchange create() {
             return new DHG1();
         }
 
+        @Override
         public String getName() {
             return "diffie-hellman-group1-sha1";
         }
@@ -59,8 +61,8 @@ public class DHG1
 
     @Override
     protected void initDH(DH dh) {
-        dh.setG(DHGroupData.getG());
-        dh.setP(DHGroupData.getP1());
+        dh.setG(DHGroupData.G);
+        dh.setP(DHGroupData.P1);
     }
 
 }

src/main/java/net/schmizz/sshj/transport/kex/DHG14.java

@@ -48,10 +48,12 @@ public class DHG14
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<KeyExchange> {
 
+        @Override
         public KeyExchange create() {
             return new DHG14();
         }
 
+        @Override
         public String getName() {
             return "diffie-hellman-group14-sha1";
         }
@@ -60,8 +62,8 @@ public class DHG14
 
     @Override
     protected void initDH(DH dh) {
-        dh.setG(DHGroupData.getG());
-        dh.setP(DHGroupData.getP14());
+        dh.setG(DHGroupData.G);
+        dh.setP(DHGroupData.P14);
     }
 
 }

src/main/java/net/schmizz/sshj/transport/kex/DHGroupData.java

@@ -35,70 +35,28 @@
  */
 package net.schmizz.sshj.transport.kex;
 
+import java.math.BigInteger;
+
 /** Simple class holding the data for DH group key exchanges. */
 public final class DHGroupData {
 
-    public static byte[] getG() {
-        final byte[] G = {2};
-        return G;
-    }
+    public static final BigInteger G =
+            new BigInteger("2");
 
-    public static byte[] getP1() {
-        final byte[] P_1 = {(byte) 0x00, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
-                (byte) 0xFF, (byte) 0xFF, (byte) 0xC9, (byte) 0x0F, (byte) 0xDA, (byte) 0xA2, (byte) 0x21, (byte) 0x68,
-                (byte) 0xC2, (byte) 0x34, (byte) 0xC4, (byte) 0xC6, (byte) 0x62, (byte) 0x8B, (byte) 0x80, (byte) 0xDC,
-                (byte) 0x1C, (byte) 0xD1, (byte) 0x29, (byte) 0x02, (byte) 0x4E, (byte) 0x08, (byte) 0x8A, (byte) 0x67,
-                (byte) 0xCC, (byte) 0x74, (byte) 0x02, (byte) 0x0B, (byte) 0xBE, (byte) 0xA6, (byte) 0x3B, (byte) 0x13,
-                (byte) 0x9B, (byte) 0x22, (byte) 0x51, (byte) 0x4A, (byte) 0x08, (byte) 0x79, (byte) 0x8E, (byte) 0x34,
-                (byte) 0x04, (byte) 0xDD, (byte) 0xEF, (byte) 0x95, (byte) 0x19, (byte) 0xB3, (byte) 0xCD, (byte) 0x3A,
-                (byte) 0x43, (byte) 0x1B, (byte) 0x30, (byte) 0x2B, (byte) 0x0A, (byte) 0x6D, (byte) 0xF2, (byte) 0x5F,
-                (byte) 0x14, (byte) 0x37, (byte) 0x4F, (byte) 0xE1, (byte) 0x35, (byte) 0x6D, (byte) 0x6D, (byte) 0x51,
-                (byte) 0xC2, (byte) 0x45, (byte) 0xE4, (byte) 0x85, (byte) 0xB5, (byte) 0x76, (byte) 0x62, (byte) 0x5E,
-                (byte) 0x7E, (byte) 0xC6, (byte) 0xF4, (byte) 0x4C, (byte) 0x42, (byte) 0xE9, (byte) 0xA6, (byte) 0x37,
-                (byte) 0xED, (byte) 0x6B, (byte) 0x0B, (byte) 0xFF, (byte) 0x5C, (byte) 0xB6, (byte) 0xF4, (byte) 0x06,
-                (byte) 0xB7, (byte) 0xED, (byte) 0xEE, (byte) 0x38, (byte) 0x6B, (byte) 0xFB, (byte) 0x5A, (byte) 0x89,
-                (byte) 0x9F, (byte) 0xA5, (byte) 0xAE, (byte) 0x9F, (byte) 0x24, (byte) 0x11, (byte) 0x7C, (byte) 0x4B,
-                (byte) 0x1F, (byte) 0xE6, (byte) 0x49, (byte) 0x28, (byte) 0x66, (byte) 0x51, (byte) 0xEC, (byte) 0xE6,
-                (byte) 0x53, (byte) 0x81, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
-                (byte) 0xFF, (byte) 0xFF};
-        return P_1;
-    }
+    public static final BigInteger P1 =
+            new BigInteger("1797693134862315907708391567937874531978602960487560117064444236841971802161585193" +
+                           "6894783379586492554150218056548598050364644054819923910005079287700335581663922955" +
+                           "3136239076508735759914822574862575007425302077447712589550957937778424442426617334" +
+                           "727629299387668709205606050270810842907692932019128194467627007");
 
-    public static byte[] getP14() {
-        final byte[] P_14 = {(byte) 0x00, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
-                (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xC9, (byte) 0x0F, (byte) 0xDA, (byte) 0xA2, (byte) 0x21,
-                (byte) 0x68, (byte) 0xC2, (byte) 0x34, (byte) 0xC4, (byte) 0xC6, (byte) 0x62, (byte) 0x8B, (byte) 0x80,
-                (byte) 0xDC, (byte) 0x1C, (byte) 0xD1, (byte) 0x29, (byte) 0x02, (byte) 0x4E, (byte) 0x08, (byte) 0x8A,
-                (byte) 0x67, (byte) 0xCC, (byte) 0x74, (byte) 0x02, (byte) 0x0B, (byte) 0xBE, (byte) 0xA6, (byte) 0x3B,
-                (byte) 0x13, (byte) 0x9B, (byte) 0x22, (byte) 0x51, (byte) 0x4A, (byte) 0x08, (byte) 0x79, (byte) 0x8E,
-                (byte) 0x34, (byte) 0x04, (byte) 0xDD, (byte) 0xEF, (byte) 0x95, (byte) 0x19, (byte) 0xB3, (byte) 0xCD,
-                (byte) 0x3A, (byte) 0x43, (byte) 0x1B, (byte) 0x30, (byte) 0x2B, (byte) 0x0A, (byte) 0x6D, (byte) 0xF2,
-                (byte) 0x5F, (byte) 0x14, (byte) 0x37, (byte) 0x4F, (byte) 0xE1, (byte) 0x35, (byte) 0x6D, (byte) 0x6D,
-                (byte) 0x51, (byte) 0xC2, (byte) 0x45, (byte) 0xE4, (byte) 0x85, (byte) 0xB5, (byte) 0x76, (byte) 0x62,
-                (byte) 0x5E, (byte) 0x7E, (byte) 0xC6, (byte) 0xF4, (byte) 0x4C, (byte) 0x42, (byte) 0xE9, (byte) 0xA6,
-                (byte) 0x37, (byte) 0xED, (byte) 0x6B, (byte) 0x0B, (byte) 0xFF, (byte) 0x5C, (byte) 0xB6, (byte) 0xF4,
-                (byte) 0x06, (byte) 0xB7, (byte) 0xED, (byte) 0xEE, (byte) 0x38, (byte) 0x6B, (byte) 0xFB, (byte) 0x5A,
-                (byte) 0x89, (byte) 0x9F, (byte) 0xA5, (byte) 0xAE, (byte) 0x9F, (byte) 0x24, (byte) 0x11, (byte) 0x7C,
-                (byte) 0x4B, (byte) 0x1F, (byte) 0xE6, (byte) 0x49, (byte) 0x28, (byte) 0x66, (byte) 0x51, (byte) 0xEC,
-                (byte) 0xE4, (byte) 0x5B, (byte) 0x3D, (byte) 0xC2, (byte) 0x00, (byte) 0x7C, (byte) 0xB8, (byte) 0xA1,
-                (byte) 0x63, (byte) 0xBF, (byte) 0x05, (byte) 0x98, (byte) 0xDA, (byte) 0x48, (byte) 0x36, (byte) 0x1C,
-                (byte) 0x55, (byte) 0xD3, (byte) 0x9A, (byte) 0x69, (byte) 0x16, (byte) 0x3F, (byte) 0xA8, (byte) 0xFD,
-                (byte) 0x24, (byte) 0xCF, (byte) 0x5F, (byte) 0x83, (byte) 0x65, (byte) 0x5D, (byte) 0x23, (byte) 0xDC,
-                (byte) 0xA3, (byte) 0xAD, (byte) 0x96, (byte) 0x1C, (byte) 0x62, (byte) 0xF3, (byte) 0x56, (byte) 0x20,
-                (byte) 0x85, (byte) 0x52, (byte) 0xBB, (byte) 0x9E, (byte) 0xD5, (byte) 0x29, (byte) 0x07, (byte) 0x70,
-                (byte) 0x96, (byte) 0x96, (byte) 0x6D, (byte) 0x67, (byte) 0x0C, (byte) 0x35, (byte) 0x4E, (byte) 0x4A,
-                (byte) 0xBC, (byte) 0x98, (byte) 0x04, (byte) 0xF1, (byte) 0x74, (byte) 0x6C, (byte) 0x08, (byte) 0xCA,
-                (byte) 0x18, (byte) 0x21, (byte) 0x7C, (byte) 0x32, (byte) 0x90, (byte) 0x5E, (byte) 0x46, (byte) 0x2E,
-                (byte) 0x36, (byte) 0xCE, (byte) 0x3B, (byte) 0xE3, (byte) 0x9E, (byte) 0x77, (byte) 0x2C, (byte) 0x18,
-                (byte) 0x0E, (byte) 0x86, (byte) 0x03, (byte) 0x9B, (byte) 0x27, (byte) 0x83, (byte) 0xA2, (byte) 0xEC,
-                (byte) 0x07, (byte) 0xA2, (byte) 0x8F, (byte) 0xB5, (byte) 0xC5, (byte) 0x5D, (byte) 0xF0, (byte) 0x6F,
-                (byte) 0x4C, (byte) 0x52, (byte) 0xC9, (byte) 0xDE, (byte) 0x2B, (byte) 0xCB, (byte) 0xF6, (byte) 0x95,
-                (byte) 0x58, (byte) 0x17, (byte) 0x18, (byte) 0x39, (byte) 0x95, (byte) 0x49, (byte) 0x7C, (byte) 0xEA,
-                (byte) 0x95, (byte) 0x6A, (byte) 0xE5, (byte) 0x15, (byte) 0xD2, (byte) 0x26, (byte) 0x18, (byte) 0x98,
-                (byte) 0xFA, (byte) 0x05, (byte) 0x10, (byte) 0x15, (byte) 0x72, (byte) 0x8E, (byte) 0x5A, (byte) 0x8A,
-                (byte) 0xAC, (byte) 0xAA, (byte) 0x68, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
-                (byte) 0xFF, (byte) 0xFF, (byte) 0xFF};
-        return P_14;
-    }
+    public static final BigInteger P14 =
+            new BigInteger("3231700607131100730033891392642382824881794124114023911284200975140074170663435422" +
+                           "2619689417363569347117901737909704191754605873209195028853758986185622153212175412" +
+                           "5149017745202702357960782362488842461894775876411059286460994117232454266225221932" +
+                           "3054091903768052423551912567971587011700105805587765103886184728025797605490356973" +
+                           "2561526167081339361799541336476559160368317896729073178384589680639671900977202194" +
+                           "1686472258710314113364293195361934716365332097170774482279885885653692086452966360" +
+                           "7725026895550592836275112117409697299806841055435958486658329164213621823107899099" +
+                           "9448652468262416972035911852507045361090559");
 
 }

src/main/java/net/schmizz/sshj/transport/kex/KeyExchange.java

@@ -41,14 +41,33 @@ import net.schmizz.sshj.transport.Transport;
 import net.schmizz.sshj.transport.TransportException;
 import net.schmizz.sshj.transport.digest.Digest;
 
+import java.security.GeneralSecurityException;
 import java.security.PublicKey;
 
 /** Key exchange algorithm. */
 public interface KeyExchange {
 
+    /**
+     * Initialize the key exchange algorithm.
+     *
+     * @param trans the transport
+     * @param V_S   the server identification string
+     * @param V_C   the client identification string
+     * @param I_S   the server key init packet
+     * @param I_C   the client key init packet
+     *
+     * @throws GeneralSecurityException
+     * @throws TransportException       if there is an error sending a packet
+     */
+    void init(Transport trans, byte[] V_S, byte[] V_C, byte[] I_S, byte[] I_C)
+            throws GeneralSecurityException, TransportException;
+
     /** @return the computed H parameter */
     byte[] getH();
 
+    /** @return the computed K parameter */
+    byte[] getK();
+
     /**
      * The message digest used by this key exchange algorithm.
      *
@@ -59,23 +78,6 @@ public interface KeyExchange {
     /** @return the host key determined from server's response packets */
     PublicKey getHostKey();
 
-    /** @return the computed K parameter */
-    byte[] getK();
-
-    /**
-     * Initialize the key exchange algorithm.
-     *
-     * @param trans the transport
-     * @param V_S   the server identification string
-     * @param V_C   the client identification string
-     * @param I_S   the server key init packet
-     * @param I_C   the client key init packet
-     *
-     * @throws TransportException if there is an error sending a packet
-     */
-    void init(Transport trans, byte[] V_S, byte[] V_C, byte[] I_S, byte[] I_C)
-            throws TransportException;
-
     /**
      * Process the next packet
      *
@@ -84,9 +86,10 @@ public interface KeyExchange {
      *
      * @return a boolean indicating if the processing is complete or if more packets are to be received
      *
-     * @throws TransportException if there is an error sending a packet
+     * @throws GeneralSecurityException
+     * @throws TransportException       if there is an error sending a packet
      */
     boolean next(Message msg, SSHPacket buffer)
-            throws TransportException;
+            throws GeneralSecurityException, TransportException;
 
 }

src/main/java/net/schmizz/sshj/transport/mac/BaseMAC.java

@@ -59,14 +59,17 @@ public class BaseMAC
         tmp = new byte[defbsize];
     }
 
+    @Override
     public byte[] doFinal() {
         return mac.doFinal();
     }
 
+    @Override
     public byte[] doFinal(byte[] input) {
         return mac.doFinal(input);
     }
 
+    @Override
     public void doFinal(byte[] buf, int offset) {
         try {
             if (bsize != defbsize) {
@@ -79,10 +82,12 @@ public class BaseMAC
         }
     }
 
+    @Override
     public int getBlockSize() {
         return bsize;
     }
 
+    @Override
     public void init(byte[] key) {
         if (key.length > defbsize) {
             byte[] tmp = new byte[defbsize];
@@ -99,14 +104,17 @@ public class BaseMAC
         }
     }
 
+    @Override
     public void update(byte foo[], int s, int l) {
         mac.update(foo, s, l);
     }
 
+    @Override
     public void update(byte[] foo) {
         mac.update(foo, 0, foo.length);
     }
 
+    @Override
     public void update(long i) {
         tmp[0] = (byte) (i >>> 24);
         tmp[1] = (byte) (i >>> 16);

src/main/java/net/schmizz/sshj/transport/mac/HMACMD5.java

@@ -43,10 +43,12 @@ public class HMACMD5
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<MAC> {
 
+        @Override
         public MAC create() {
             return new HMACMD5();
         }
 
+        @Override
         public String getName() {
             return "hmac-md5";
         }

src/main/java/net/schmizz/sshj/transport/mac/HMACMD596.java

@@ -43,10 +43,12 @@ public class HMACMD596
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<MAC> {
 
+        @Override
         public MAC create() {
             return new HMACMD596();
         }
 
+        @Override
         public String getName() {
             return "hmac-md5-96";
         }

src/main/java/net/schmizz/sshj/transport/mac/HMACSHA1.java

@@ -43,10 +43,12 @@ public class HMACSHA1
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<MAC> {
 
+        @Override
         public MAC create() {
             return new HMACSHA1();
         }
 
+        @Override
         public String getName() {
             return "hmac-sha1";
         }

src/main/java/net/schmizz/sshj/transport/mac/HMACSHA196.java

@@ -43,10 +43,12 @@ public class HMACSHA196
     public static class Factory
             implements net.schmizz.sshj.common.Factory.Named<MAC> {
 
+        @Override
         public MAC create() {
             return new HMACSHA196();
         }
 
+        @Override
         public String getName() {
             return "hmac-sha1-96";
         }