support sftp versions < 3

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;
@@ -592,8 +593,21 @@ public class SSHClient
      */
     public SFTPClient newSFTPClient()
             throws IOException {
+        return newSFTPClient(SFTPEngine.MAX_SUPPORTED_VERSION);
+    }
+
+    /**
+     * @param version the protocol version to use
+     *
+     * @return Instantiated {@link SFTPClient} implementation.
+     *
+     * @throws IOException if there is an error starting the {@code sftp} subsystem
+     * @see StatefulSFTPClient
+     */
+    public SFTPClient newSFTPClient(int version)
+            throws IOException {
         assert isConnected() && isAuthenticated();
-        return new SFTPClient(this);
+        return new SFTPClient(new SFTPEngine(this, version).init());
     }
 
     /**

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) {
+    public PacketReader(SFTPEngine engine) {
-        this.in = in;
+        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/PathHelper.java

@@ -19,11 +19,11 @@ import java.io.IOException;
 
 public class PathHelper {
 
-    private final SFTPEngine sftp;
+    private final SFTPEngine engine;
     private String dotDir;
 
-    public PathHelper(SFTPEngine sftp) {
+    public PathHelper(SFTPEngine engine) {
-        this.sftp = sftp;
+        this.engine = engine;
     }
 
     public PathComponents getComponents(String path)
@@ -56,7 +56,7 @@ public class PathHelper {
 
     private String canon(String path)
             throws IOException {
-        return sftp.canonicalize(path);
+        return engine.canonicalize(path);
     }
 
 }

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 */

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;
     }
 
+    private String error(StatusCode sc)
+            throws SFTPException {
+        throw new SFTPException(sc, protocolVersion < 3 ? sc.toString() : readString());
+    }
+
 }

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

@@ -15,7 +15,6 @@
  */
 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;
@@ -34,19 +33,18 @@ public class SFTPClient
     /** 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)
+    public SFTPClient(SFTPEngine engine) {
-            throws IOException {
+        this.engine = engine;
-        this.sftp = new SFTPEngine(ssh).init();
+        this.pathHelper = new PathHelper(engine);
-        this.pathHelper = new PathHelper(sftp);
+        this.xfer = new SFTPFileTransfer(engine);
-        this.xfer = new SFTPFileTransfer(sftp);
     }
 
     public SFTPEngine getSFTPEngine() {
-        return sftp;
+        return engine;
     }
 
     public SFTPFileTransfer getFileTansfer() {
@@ -60,7 +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 {
@@ -71,7 +69,7 @@ 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)
@@ -86,7 +84,7 @@ public class SFTPClient
 
     public void mkdir(String dirname)
             throws IOException {
-        sftp.makeDir(dirname);
+        engine.makeDir(dirname);
     }
 
     public void mkdirs(String path)
@@ -111,7 +109,7 @@ public class SFTPClient
     public FileAttributes statExistence(String path)
             throws IOException {
         try {
-            return sftp.stat(path);
+            return engine.stat(path);
         } catch (SFTPException sftpe) {
             if (sftpe.getStatusCode() == Response.StatusCode.NO_SUCH_FILE) {
                 return null;
@@ -123,31 +121,31 @@ public class SFTPClient
 
     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)
@@ -187,17 +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)
@@ -222,7 +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)
@@ -243,7 +241,7 @@ public class SFTPClient
     @Override
     public void close()
             throws IOException {
-        sftp.close();
+        engine.close();
     }
 
 }

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

@@ -33,37 +33,41 @@ import java.util.concurrent.TimeUnit;
 public class SFTPEngine
         implements Requester, Closeable {
 
-    /** Logger */
+    public static final int MAX_SUPPORTED_VERSION = 3;
-    private final Logger log = LoggerFactory.getLogger(getClass());
-
-    public static final int PROTOCOL_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;
+    protected volatile int timeout = DEFAULT_TIMEOUT;
-    private final PacketReader reader;
-    private final OutputStream out;
 
-    private long reqID;
+    protected final int clientVersion;
-    private int negotiatedVersion;
+    protected final Subsystem sub;
-    private final Map<String, String> serverExtensions = new HashMap<String, String>();
+    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");
+        this(ssh, MAX_SUPPORTED_VERSION);
-        out = sub.getOutputStream();
-        reader = new PacketReader(sub.getInputStream());
     }
 
-    public Subsystem getSubsystem() {
+    public SFTPEngine(SessionFactory ssh, int clientVersion)
-        return sub;
+            throws SSHException {
+        if (clientVersion > MAX_SUPPORTED_VERSION)
+            throw new SFTPException("Max. supported protocol version is: " + MAX_SUPPORTED_VERSION);
+        this.clientVersion = clientVersion;
+        sub = ssh.startSession().startSubsystem("sftp");
+        out = sub.getOutputStream();
+        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(clientVersion));
 
         final SFTPPacket<Response> response = reader.readPacket();
 
@@ -71,10 +75,10 @@ public class SFTPEngine
         if (type != PacketType.VERSION)
             throw new SFTPException("Expected INIT packet, received: " + type);
 
-        negotiatedVersion = response.readInt();
+        operativeVersion = response.readInt();
-        log.info("Client version {}, server version {}", PROTOCOL_VERSION, negotiatedVersion);
+        log.info("Client version {}, server version {}", clientVersion, operativeVersion);
-        if (negotiatedVersion < PROTOCOL_VERSION)
+        if (operativeVersion < clientVersion)
-            throw new SFTPException("Server reported protocol version: " + negotiatedVersion);
+            throw new SFTPException("Server reported protocol version: " + operativeVersion);
 
         while (response.available() > 0)
             serverExtensions.put(response.readString(), response.readString());
@@ -84,8 +88,16 @@ public class SFTPEngine
         return this;
     }
 
+    public Subsystem getSubsystem() {
+        return sub;
+    }
+
     public int getOperativeProtocolVersion() {
-        return negotiatedVersion;
+        return operativeVersion;
+    }
+
+    public Request newExtendedRequest(String reqName) {
+        return newRequest(PacketType.EXTENDED).putString(reqName);
     }
 
     @Override
@@ -102,17 +114,6 @@ 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(
@@ -148,6 +149,8 @@ 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)
@@ -166,6 +169,8 @@ public class SFTPEngine
 
     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 +190,6 @@ 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 +202,8 @@ 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 +217,6 @@ 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;
     }
@@ -240,4 +231,31 @@ public class SFTPEngine
         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

@@ -67,7 +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

@@ -33,7 +33,7 @@ public class SFTPFileTransfer
         extends AbstractFileTransfer
         implements FileTransfer {
 
-    private final SFTPEngine sftp;
+    private final SFTPEngine engine;
     private final PathHelper pathHelper;
 
     private volatile FileFilter uploadFilter = defaultLocalFilter;
@@ -53,9 +53,9 @@ public class SFTPFileTransfer
         }
     };
 
-    public SFTPFileTransfer(SFTPEngine sftp) {
+    public SFTPFileTransfer(SFTPEngine engine) {
-        this.sftp = sftp;
+        this.engine = engine;
-        this.pathHelper = new PathHelper(sftp);
+        this.pathHelper = new PathHelper(engine);
     }
 
     @Override
@@ -68,7 +68,7 @@ public class SFTPFileTransfer
     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));
     }
 
@@ -119,7 +119,7 @@ public class SFTPFileTransfer
         private File downloadDir(final RemoteResourceInfo remote, final File local)
                 throws IOException {
             final File adjusted = FileTransferUtil.getTargetDirectory(local, remote.getName());
-            final RemoteDirectory rd = sftp.openDir(remote.getPath());
+            final RemoteDirectory rd = engine.openDir(remote.getPath());
             try {
                 for (RemoteResourceInfo rri : rd.scan(getDownloadFilter()))
                     download(rri, new File(adjusted.getPath(), rri.getName()));
@@ -132,11 +132,11 @@ public class SFTPFileTransfer
         private File downloadFile(final RemoteResourceInfo remote, final File local)
                 throws IOException {
             final File adjusted = FileTransferUtil.getTargetFile(local, remote.getName());
-            final RemoteFile rf = sftp.open(remote.getPath());
+            final RemoteFile rf = engine.open(remote.getPath());
             try {
                 final FileOutputStream fos = new FileOutputStream(adjusted);
                 try {
-                    StreamCopier.copy(rf.getInputStream(), fos, sftp.getSubsystem()
+                    StreamCopier.copy(rf.getInputStream(), fos, engine.getSubsystem()
                             .getLocalMaxPacketSize(), false, listener);
                 } finally {
                     fos.close();
@@ -176,7 +176,7 @@ public class SFTPFileTransfer
                 listener.finishedFile();
             } else
                 throw new IOException(local + " is not a file or directory");
-            sftp.setAttributes(adjustedPath, getAttributes(local));
+            engine.setAttributes(adjustedPath, getAttributes(local));
         }
 
         private String uploadDir(File local, String remote)
@@ -190,13 +190,13 @@ public class SFTPFileTransfer
         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,
+            final RemoteFile rf = engine.open(adjusted, EnumSet.of(OpenMode.WRITE,
-                                                                 OpenMode.CREAT,
+                                                                   OpenMode.CREAT,
-                                                                 OpenMode.TRUNC));
+                                                                   OpenMode.TRUNC));
             try {
                 final FileInputStream fis = new FileInputStream(local);
                 try {
-                    final int bufSize = sftp.getSubsystem().getRemoteMaxPacketSize() - rf.getOutgoingPacketOverhead();
+                    final int bufSize = engine.getSubsystem().getRemoteMaxPacketSize() - rf.getOutgoingPacketOverhead();
                     StreamCopier.copy(fis, rf.getOutputStream(), bufSize, false, listener);
                 } finally {
                     fis.close();
@@ -211,11 +211,11 @@ 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("probeDir: {} does not exist, creating", remote);
-                    sftp.makeDir(remote);
+                    engine.makeDir(remote);
                     return remote;
                 } else
                     throw e;
@@ -237,7 +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);

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);
     }