--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/ch/ethz/ssh2/SFTPv3Client.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,433 @@
+/*
+ * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
+ * Please refer to the LICENSE.txt for licensing details.
+ */
+package ch.ethz.ssh2;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import ch.ethz.ssh2.log.Logger;
+import ch.ethz.ssh2.packets.TypesReader;
+import ch.ethz.ssh2.packets.TypesWriter;
+import ch.ethz.ssh2.sftp.ErrorCodes;
+import ch.ethz.ssh2.sftp.Packet;
+
+/**
+ * A <code>SFTPv3Client</code> represents a SFTP (protocol version 3)
+ * client connection tunnelled over a SSH-2 connection. This is a very simple
+ * (synchronous) implementation.
+ * <p/>
+ * Basically, most methods in this class map directly to one of
+ * the packet types described in draft-ietf-secsh-filexfer-02.txt.
+ * <p/>
+ * Note: this is experimental code.
+ * <p/>
+ * Error handling: the methods of this class throw IOExceptions. However, unless
+ * there is catastrophic failure, exceptions of the type {@link SFTPv3Client} will
+ * be thrown (a subclass of IOException). Therefore, you can implement more verbose
+ * behavior by checking if a thrown exception if of this type. If yes, then you
+ * can cast the exception and access detailed information about the failure.
+ * <p/>
+ * Notes about file names, directory names and paths, copy-pasted
+ * from the specs:
+ * <ul>
+ * <li>SFTP v3 represents file names as strings. File names are
+ * assumed to use the slash ('/') character as a directory separator.</li>
+ * <li>File names starting with a slash are "absolute", and are relative to
+ * the root of the file system.  Names starting with any other character
+ * are relative to the user's default directory (home directory).</li>
+ * <li>Servers SHOULD interpret a path name component ".." as referring to
+ * the parent directory, and "." as referring to the current directory.
+ * If the server implementation limits access to certain parts of the
+ * file system, it must be extra careful in parsing file names when
+ * enforcing such restrictions.  There have been numerous reported
+ * security bugs where a ".." in a path name has allowed access outside
+ * the intended area.</li>
+ * <li>An empty path name is valid, and it refers to the user's default
+ * directory (usually the user's home directory).</li>
+ * </ul>
+ * <p/>
+ * If you are still not tired then please go on and read the comment for
+ * {@link #setCharset(String)}.
+ *
+ * @author Christian Plattner, plattner@inf.ethz.ch
+ * @version $Id: SFTPv3Client.java 133 2014-04-14 12:26:29Z dkocher@sudo.ch $
+ */
+public class SFTPv3Client extends AbstractSFTPClient {
+    private static final Logger log = Logger.getLogger(SFTPv3Client.class);
+
+    /**
+     * Open the file for reading.
+     */
+    public static final int SSH_FXF_READ = 0x00000001;
+    /**
+     * Open the file for writing.  If both this and SSH_FXF_READ are
+     * specified, the file is opened for both reading and writing.
+     */
+    public static final int SSH_FXF_WRITE = 0x00000002;
+    /**
+     * Force all writes to append data at the end of the file.
+     */
+    public static final int SSH_FXF_APPEND = 0x00000004;
+    /**
+     * If this flag is specified, then a new file will be created if one
+     * does not alread exist (if O_TRUNC is specified, the new file will
+     * be truncated to zero length if it previously exists).
+     */
+    public static final int SSH_FXF_CREAT = 0x00000008;
+    /**
+     * Forces an existing file with the same name to be truncated to zero
+     * length when creating a file by specifying SSH_FXF_CREAT.
+     * SSH_FXF_CREAT MUST also be specified if this flag is used.
+     */
+    public static final int SSH_FXF_TRUNC = 0x00000010;
+    /**
+     * Causes the request to fail if the named file already exists.
+     */
+    public static final int SSH_FXF_EXCL = 0x00000020;
+
+    private PacketListener listener;
+
+    /**
+     * Create a SFTP v3 client.
+     *
+     * @param conn The underlying SSH-2 connection to be used.
+     * @throws IOException
+     */
+    public SFTPv3Client(Connection conn) throws IOException {
+        this(conn, new PacketListener() {
+            public void read(String packet) {
+                log.debug("Read packet " + packet);
+            }
+            public void write(String packet) {
+                log.debug("Write packet " + packet);
+            }
+        });
+    }
+
+    /**
+     * Create a SFTP v3 client.
+     *
+     * @param conn The underlying SSH-2 connection to be used.
+     * @throws IOException
+     */
+    public SFTPv3Client(Connection conn, PacketListener listener) throws IOException {
+        super(conn, 3, listener);
+        this.listener = listener;
+    }
+
+    public SFTPv3FileAttributes fstat(SFTPFileHandle handle) throws IOException {
+        int req_id = generateNextRequestID();
+        TypesWriter tw = new TypesWriter();
+        tw.writeString(handle.getHandle(), 0, handle.getHandle().length);
+        sendMessage(Packet.SSH_FXP_FSTAT, req_id, tw.getBytes());
+        byte[] resp = receiveMessage(34000);
+        TypesReader tr = new TypesReader(resp);
+        int t = tr.readByte();
+        listener.read(Packet.forName(t));
+        int rep_id = tr.readUINT32();
+
+        if (rep_id != req_id) {
+            throw new RequestMismatchException();
+        }
+
+        if (t == Packet.SSH_FXP_ATTRS) {
+            return new SFTPv3FileAttributes(tr);
+        }
+
+        if (t != Packet.SSH_FXP_STATUS) {
+            throw new PacketTypeException(t);
+        }
+
+        int errorCode = tr.readUINT32();
+        String errorMessage = tr.readString();
+        listener.read(errorMessage);
+        throw new SFTPException(errorMessage, errorCode);
+    }
+
+    private SFTPv3FileAttributes statBoth(String path, int statMethod) throws IOException {
+        int req_id = generateNextRequestID();
+        TypesWriter tw = new TypesWriter();
+        tw.writeString(path, this.getCharset());
+        sendMessage(statMethod, req_id, tw.getBytes());
+        byte[] resp = receiveMessage(34000);
+        TypesReader tr = new TypesReader(resp);
+        int t = tr.readByte();
+        listener.read(Packet.forName(t));
+        int rep_id = tr.readUINT32();
+
+        if (rep_id != req_id) {
+            throw new RequestMismatchException();
+        }
+
+        if (t == Packet.SSH_FXP_ATTRS) {
+            return new SFTPv3FileAttributes(tr);
+        }
+
+        if (t != Packet.SSH_FXP_STATUS) {
+            throw new PacketTypeException(t);
+        }
+
+        int errorCode = tr.readUINT32();
+        String errorMessage = tr.readString();
+        listener.read(errorMessage);
+        throw new SFTPException(errorMessage, errorCode);
+    }
+
+    public SFTPv3FileAttributes stat(String path) throws IOException {
+        return statBoth(path, Packet.SSH_FXP_STAT);
+    }
+
+    public SFTPv3FileAttributes lstat(String path) throws IOException {
+        return statBoth(path, Packet.SSH_FXP_LSTAT);
+    }
+
+
+    private List<SFTPv3DirectoryEntry> scanDirectory(byte[] handle) throws IOException {
+        List<SFTPv3DirectoryEntry> files = new ArrayList<SFTPv3DirectoryEntry>();
+
+        while (true) {
+            int req_id = generateNextRequestID();
+            TypesWriter tw = new TypesWriter();
+            tw.writeString(handle, 0, handle.length);
+            sendMessage(Packet.SSH_FXP_READDIR, req_id, tw.getBytes());
+            byte[] resp = receiveMessage(34000);
+            TypesReader tr = new TypesReader(resp);
+            int t = tr.readByte();
+            listener.read(Packet.forName(t));
+            int rep_id = tr.readUINT32();
+
+            if (rep_id != req_id) {
+                throw new RequestMismatchException();
+            }
+
+            if (t == Packet.SSH_FXP_NAME) {
+                int count = tr.readUINT32();
+
+                if (log.isDebugEnabled()) {
+                    log.debug(String.format("Parsing %d name entries", count));
+                }
+
+                while (count > 0) {
+                    SFTPv3DirectoryEntry file = new SFTPv3DirectoryEntry();
+                    file.filename = tr.readString(this.getCharset());
+                    file.longEntry = tr.readString(this.getCharset());
+                    listener.read(file.longEntry);
+                    file.attributes = new SFTPv3FileAttributes(tr);
+
+                    if (log.isDebugEnabled()) {
+                        log.debug(String.format("Adding file %s", file));
+                    }
+
+                    files.add(file);
+                    count--;
+                }
+
+                continue;
+            }
+
+            if (t != Packet.SSH_FXP_STATUS) {
+                throw new PacketTypeException(t);
+            }
+
+            int errorCode = tr.readUINT32();
+
+            if (errorCode == ErrorCodes.SSH_FX_EOF) {
+                return files;
+            }
+
+            String errorMessage = tr.readString();
+            listener.read(errorMessage);
+            throw new SFTPException(errorMessage, errorCode);
+        }
+    }
+
+    public final SFTPv3FileHandle openDirectory(String path) throws IOException {
+        int req_id = generateNextRequestID();
+        TypesWriter tw = new TypesWriter();
+        tw.writeString(path, this.getCharset());
+        sendMessage(Packet.SSH_FXP_OPENDIR, req_id, tw.getBytes());
+        byte[] resp = receiveMessage(34000);
+        TypesReader tr = new TypesReader(resp);
+        int t = tr.readByte();
+        listener.read(Packet.forName(t));
+        int rep_id = tr.readUINT32();
+
+        if (rep_id != req_id) {
+            throw new RequestMismatchException();
+        }
+
+        if (t == Packet.SSH_FXP_HANDLE) {
+            return new SFTPv3FileHandle(this, tr.readByteString());
+        }
+
+        if (t != Packet.SSH_FXP_STATUS) {
+            throw new PacketTypeException(t);
+        }
+
+        int errorCode = tr.readUINT32();
+        String errorMessage = tr.readString();
+        listener.read(errorMessage);
+        throw new SFTPException(errorMessage, errorCode);
+    }
+
+    /**
+     * List the contents of a directory.
+     *
+     * @param dirName See the {@link SFTPv3Client comment} for the class for more details.
+     * @return A Vector containing {@link SFTPv3DirectoryEntry} objects.
+     * @throws IOException
+     */
+    public List<SFTPv3DirectoryEntry> ls(String dirName) throws IOException {
+        SFTPv3FileHandle handle = openDirectory(dirName);
+        List<SFTPv3DirectoryEntry> result = scanDirectory(handle.getHandle());
+        closeFile(handle);
+        return result;
+    }
+
+    /**
+     * Open a file for reading.
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle openFileRO(String filename) throws IOException {
+        return openFile(filename, SSH_FXF_READ, new SFTPv3FileAttributes());
+    }
+
+    /**
+     * Open a file for reading and writing.
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle openFileRW(String filename) throws IOException {
+        return openFile(filename, SSH_FXF_READ | SSH_FXF_WRITE, new SFTPv3FileAttributes());
+    }
+
+    /**
+     * Open a file in append mode. The SFTP v3 draft says nothing but assuming normal POSIX
+     * behavior, all writes will be appendend to the end of the file, no matter which offset
+     * one specifies.
+     * <p/>
+     * A side note for the curious: OpenSSH does an lseek() to the specified writing offset before each write(),
+     * even for writes to files opened in O_APPEND mode. However, bear in mind that when working
+     * in the O_APPEND mode, each write() includes an implicit lseek() to the end of the file
+     * (well, this is what the newsgroups say).
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle openFileRWAppend(String filename) throws IOException {
+        return openFile(filename, SSH_FXF_READ | SSH_FXF_WRITE | SSH_FXF_APPEND, new SFTPv3FileAttributes());
+    }
+
+    /**
+     * Open a file in append mode. The SFTP v3 draft says nothing but assuming normal POSIX
+     * behavior, all writes will be appendend to the end of the file, no matter which offset
+     * one specifies.
+     * <p/>
+     * A side note for the curious: OpenSSH does an lseek() to the specified writing offset before each write(),
+     * even for writes to files opened in O_APPEND mode. However, bear in mind that when working
+     * in the O_APPEND mode, each write() includes an implicit lseek() to the end of the file
+     * (well, this is what the newsgroups say).
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle openFileWAppend(String filename) throws IOException {
+        return openFile(filename, SSH_FXF_WRITE | SSH_FXF_APPEND, new SFTPv3FileAttributes());
+    }
+
+    public SFTPv3FileHandle createFile(String filename) throws IOException {
+        return createFile(filename, new SFTPv3FileAttributes());
+    }
+
+    public SFTPv3FileHandle createFile(String filename, SFTPFileAttributes attr) throws IOException {
+        return openFile(filename, SSH_FXF_CREAT | SSH_FXF_READ | SSH_FXF_WRITE, attr);
+    }
+
+    /**
+     * Create a file (truncate it if it already exists) and open it for writing.
+     * Same as {@link #createFileTruncate(String, SFTPFileAttributes) createFileTruncate(filename, null)}.
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle createFileTruncate(String filename) throws IOException {
+        return createFileTruncate(filename, new SFTPv3FileAttributes());
+    }
+
+    /**
+     * reate a file (truncate it if it already exists) and open it for writing.
+     * You can specify the default attributes of the file (the server may or may
+     * not respect your wishes).
+     *
+     * @param filename See the {@link SFTPv3Client comment} for the class for more details.
+     * @param attr     may be <code>null</code> to use server defaults. Probably only
+     *                 the <code>uid</code>, <code>gid</code> and <code>permissions</code>
+     *                 (remember the server may apply a umask) entries of the {@link SFTPv3FileHandle}
+     *                 structure make sense. You need only to set those fields where you want
+     *                 to override the server's defaults.
+     * @return a SFTPv3FileHandle handle
+     * @throws IOException
+     */
+    public SFTPv3FileHandle createFileTruncate(String filename, SFTPFileAttributes attr) throws IOException {
+        return openFile(filename, SSH_FXF_CREAT | SSH_FXF_TRUNC | SSH_FXF_WRITE, attr);
+    }
+
+    public SFTPv3FileHandle openFile(String filename, int flags) throws IOException {
+        return openFile(filename, flags, new SFTPv3FileAttributes());
+    }
+
+    @Override
+    public SFTPv3FileHandle openFile(String filename, int flags, SFTPFileAttributes attr) throws IOException {
+        int req_id = generateNextRequestID();
+        TypesWriter tw = new TypesWriter();
+        tw.writeString(filename, this.getCharset());
+        tw.writeUINT32(flags);
+        tw.writeBytes(attr.toBytes());
+        sendMessage(Packet.SSH_FXP_OPEN, req_id, tw.getBytes());
+        byte[] resp = receiveMessage(34000);
+        TypesReader tr = new TypesReader(resp);
+        int t = tr.readByte();
+        listener.read(Packet.forName(t));
+        int rep_id = tr.readUINT32();
+
+        if (rep_id != req_id) {
+            throw new RequestMismatchException();
+        }
+
+        if (t == Packet.SSH_FXP_HANDLE) {
+            return new SFTPv3FileHandle(this, tr.readByteString());
+        }
+
+        if (t != Packet.SSH_FXP_STATUS) {
+            throw new PacketTypeException(t);
+        }
+
+        int errorCode = tr.readUINT32();
+        String errorMessage = tr.readString();
+        listener.read(errorMessage);
+        throw new SFTPException(errorMessage, errorCode);
+    }
+
+    @Override
+    public void createSymlink(String src, String target) throws IOException {
+        int req_id = generateNextRequestID();
+        // Changed semantics of src and target. The bug is known on SFTP servers shipped with all
+        // versions of OpenSSH (Bug #861).
+        TypesWriter tw = new TypesWriter();
+        tw.writeString(target, this.getCharset());
+        tw.writeString(src, this.getCharset());
+        sendMessage(Packet.SSH_FXP_SYMLINK, req_id, tw.getBytes());
+        expectStatusOKMessage(req_id);
+    }
+}