Package com.trilead.ssh2

Class SFTPv3Client

  • public class SFTPv3Client
extends java.lang.Object
    A SFTPv3Client represents a SFTP (protocol version 3) client connection tunnelled over a SSH-2 connection. This is a very simple (synchronous) implementation.

    Basically, most methods in this class map directly to one of the packet types described in draft-ietf-secsh-filexfer-02.txt.

    Note: this is experimental code.

    Error handling: the methods of this class throw IOExceptions. However, unless there is catastrophic failure, exceptions of the type 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.

    Notes about file names, directory names and paths, copy-pasted from the specs:

    • SFTP v3 represents file names as strings. File names are assumed to use the slash ('/') character as a directory separator.
    • 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).
    • 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.
    • An empty path name is valid, and it refers to the user's default directory (usually the user's home directory).

    If you are still not tired then please go on and read the comment for setCharset(String).

    Version:
    $Id: SFTPv3Client.java,v 1.3 2008/04/01 12:38:09 cplattne Exp $

    • Field Detail

      • debug

        final java.io.PrintStream debug

      • flag_closed

        boolean flag_closed

      • is

        java.io.InputStream is

      • os

        java.io.OutputStream os

      • protocol_version

        int protocol_version

      • server_extensions

        java.util.HashMap server_extensions

      • next_request_id

        int next_request_id

      • charsetName

        java.lang.String charsetName

    • Constructor Detail

      • SFTPv3Client

        public SFTPv3Client​(Connection conn,
                    java.io.PrintStream debug)
             throws java.io.IOException
        Deprecated.
        this constructor (debug version) will disappear in the future, use SFTPv3Client(Connection) instead.
        Create a SFTP v3 client.
        Parameters:
        conn - The underlying SSH-2 connection to be used.
        debug -
        Throws:
        java.io.IOException

      • SFTPv3Client

        public SFTPv3Client​(Connection conn)
             throws java.io.IOException
        Create a SFTP v3 client.
        Parameters:
        conn - The underlying SSH-2 connection to be used.
        Throws:
        java.io.IOException

    • Method Detail

      • setCharset

        public void setCharset​(java.lang.String charset)
                throws java.io.IOException
        Set the charset used to convert between Java Unicode Strings and byte encodings used by the server for paths and file names. Unfortunately, the SFTP v3 draft says NOTHING about such conversions (well, with the exception of error messages which have to be in UTF-8). Newer drafts specify to use UTF-8 for file names (if I remember correctly). However, a quick test using OpenSSH serving a EXT-3 filesystem has shown that UTF-8 seems to be a bad choice for SFTP v3 (tested with filenames containing german umlauts). "windows-1252" seems to work better for Europe. Luckily, "windows-1252" is the platform default in my case =).

        If you don't set anything, then the platform default will be used (this is the default behavior).

        Parameters:
        charset - the name of the charset to be used or null to use the platform's default encoding.
        Throws:
        java.io.IOException
        See Also:
        getCharset()

      • getCharset

        public java.lang.String getCharset()
        The currently used charset for filename encoding/decoding.
        Returns:
        The name of the charset (null if the platform's default charset is being used)
        See Also:
        setCharset(String)

      • checkHandleValidAndOpen

        private final void checkHandleValidAndOpen​(SFTPv3FileHandle handle)
                                    throws java.io.IOException
        Throws:
        java.io.IOException

      • sendMessage

        private final void sendMessage​(int type,
                               int requestId,
                               byte[] msg,
                               int off,
                               int len)
                        throws java.io.IOException
        Throws:
        java.io.IOException

      • sendMessage

        private final void sendMessage​(int type,
                               int requestId,
                               byte[] msg)
                        throws java.io.IOException
        Throws:
        java.io.IOException

      • readBytes

        private final void readBytes​(byte[] buff,
                             int pos,
                             int len)
                      throws java.io.IOException
        Throws:
        java.io.IOException

      • receiveMessage

        private final byte[] receiveMessage​(int maxlen)
                             throws java.io.IOException
        Read a message and guarantee that the contents is not larger than maxlen bytes.

        Note: receiveMessage(34000) actually means that the message may be up to 34004 bytes (the length attribute preceeding the contents is 4 bytes).

        Parameters:
        maxlen -
        Returns:
        the message contents
        Throws:
        java.io.IOException

      • generateNextRequestID

        private final int generateNextRequestID()

      • closeHandle

        private final void closeHandle​(byte[] handle)
                        throws java.io.IOException
        Throws:
        java.io.IOException

      • fstat

        public SFTPv3FileAttributes fstat​(SFTPv3FileHandle handle)
                           throws java.io.IOException
        Retrieve the file attributes of an open file.
        Parameters:
        handle - a SFTPv3FileHandle handle.
        Returns:
        a SFTPv3FileAttributes object.
        Throws:
        java.io.IOException

      • statBoth

        private SFTPv3FileAttributes statBoth​(java.lang.String path,
                                      int statMethod)
                               throws java.io.IOException
        Throws:
        java.io.IOException

      • stat

        public SFTPv3FileAttributes stat​(java.lang.String path)
                          throws java.io.IOException
        Retrieve the file attributes of a file. This method follows symbolic links on the server.
        Parameters:
        path - See the comment for the class for more details.
        Returns:
        a SFTPv3FileAttributes object.
        Throws:
        java.io.IOException
        See Also:
        lstat(String)

      • lstat

        public SFTPv3FileAttributes lstat​(java.lang.String path)
                           throws java.io.IOException
        Retrieve the file attributes of a file. This method does NOT follow symbolic links on the server.
        Parameters:
        path - See the comment for the class for more details.
        Returns:
        a SFTPv3FileAttributes object.
        Throws:
        java.io.IOException
        See Also:
        stat(String)

      • readLink

        public java.lang.String readLink​(java.lang.String path)
                          throws java.io.IOException
        Read the target of a symbolic link.
        Parameters:
        path - See the comment for the class for more details.
        Returns:
        The target of the link.
        Throws:
        java.io.IOException

      • expectStatusOKMessage

        private void expectStatusOKMessage​(int id)
                            throws java.io.IOException
        Throws:
        java.io.IOException

      • setstat

        public void setstat​(java.lang.String path,
                    SFTPv3FileAttributes attr)
             throws java.io.IOException
        Modify the attributes of a file. Used for operations such as changing the ownership, permissions or access times, as well as for truncating a file.
        Parameters:
        path - See the comment for the class for more details.
        attr - A SFTPv3FileAttributes object. Specifies the modifications to be made to the attributes of the file. Empty fields will be ignored.
        Throws:
        java.io.IOException

      • fsetstat

        public void fsetstat​(SFTPv3FileHandle handle,
                     SFTPv3FileAttributes attr)
              throws java.io.IOException
        Modify the attributes of a file. Used for operations such as changing the ownership, permissions or access times, as well as for truncating a file.
        Parameters:
        handle - a SFTPv3FileHandle handle
        attr - A SFTPv3FileAttributes object. Specifies the modifications to be made to the attributes of the file. Empty fields will be ignored.
        Throws:
        java.io.IOException

      • createSymlink

        public void createSymlink​(java.lang.String src,
                          java.lang.String target)
                   throws java.io.IOException
        Create a symbolic link on the server. Creates a link "src" that points to "target".
        Parameters:
        src - See the comment for the class for more details.
        target - See the comment for the class for more details.
        Throws:
        java.io.IOException

      • canonicalPath

        public java.lang.String canonicalPath​(java.lang.String path)
                               throws java.io.IOException
        Have the server canonicalize any given path name to an absolute path. This is useful for converting path names containing ".." components or relative pathnames without a leading slash into absolute paths.
        Parameters:
        path - See the comment for the class for more details.
        Returns:
        An absolute path.
        Throws:
        java.io.IOException

      • scanDirectory

        private final java.util.Vector scanDirectory​(byte[] handle)
                                      throws java.io.IOException
        Throws:
        java.io.IOException

      • openDirectory

        private final byte[] openDirectory​(java.lang.String path)
                            throws java.io.IOException
        Throws:
        java.io.IOException

      • expandString

        private final java.lang.String expandString​(byte[] b,
                                            int off,
                                            int len)

      • init

        private void init()
           throws java.io.IOException
        Throws:
        java.io.IOException

      • getProtocolVersion

        public int getProtocolVersion()
        Returns the negotiated SFTP protocol version between the client and the server.
        Returns:
        SFTP protocol version, i.e., "3".

      • close

        public void close()
        Close this SFTP session. NEVER forget to call this method to free up resources - even if you got an exception from one of the other methods. Sometimes these other methods may throw an exception, saying that the underlying channel is closed (this can happen, e.g., if the other server sent a close message.) However, as long as you have not called the close() method, you are likely wasting resources.

      • ls

        public java.util.Vector ls​(java.lang.String dirName)
                    throws java.io.IOException
        List the contents of a directory.
        Parameters:
        dirName - See the comment for the class for more details.
        Returns:
        A Vector containing SFTPv3DirectoryEntry objects.
        Throws:
        java.io.IOException

      • mkdir

        public void mkdir​(java.lang.String dirName,
                  int posixPermissions)
           throws java.io.IOException
        Create a new directory.
        Parameters:
        dirName - See the comment for the class for more details.
        posixPermissions - the permissions for this directory, e.g., "0700" (remember that this is octal noation). The server will likely apply a umask.
        Throws:
        java.io.IOException

      • rm

        public void rm​(java.lang.String fileName)
        throws java.io.IOException
        Remove a file.
        Parameters:
        fileName - See the comment for the class for more details.
        Throws:
        java.io.IOException

      • rmdir

        public void rmdir​(java.lang.String dirName)
           throws java.io.IOException
        Remove an empty directory.
        Parameters:
        dirName - See the comment for the class for more details.
        Throws:
        java.io.IOException

      • mv

        public void mv​(java.lang.String oldPath,
               java.lang.String newPath)
        throws java.io.IOException
        Move a file or directory.
        Parameters:
        oldPath - See the comment for the class for more details.
        newPath - See the comment for the class for more details.
        Throws:
        java.io.IOException

      • openFileRO

        public SFTPv3FileHandle openFileRO​(java.lang.String fileName)
                            throws java.io.IOException
        Open a file for reading.
        Parameters:
        fileName - See the comment for the class for more details.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • openFileRW

        public SFTPv3FileHandle openFileRW​(java.lang.String fileName)
                            throws java.io.IOException
        Open a file for reading and writing.
        Parameters:
        fileName - See the comment for the class for more details.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • createFile

        public SFTPv3FileHandle createFile​(java.lang.String fileName)
                            throws java.io.IOException
        Create a file and open it for reading and writing. Same as createFile(fileName, null).
        Parameters:
        fileName - See the comment for the class for more details.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • createFile

        public SFTPv3FileHandle createFile​(java.lang.String fileName,
                                   SFTPv3FileAttributes attr)
                            throws java.io.IOException
        Create a file and open it for reading and writing. You can specify the default attributes of the file (the server may or may not respect your wishes).
        Parameters:
        fileName - See the comment for the class for more details.
        attr - may be null to use server defaults. Probably only the uid, gid and permissions (remember the server may apply a umask) entries of the SFTPv3FileHandle structure make sense. You need only to set those fields where you want to override the server's defaults.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • createFileTruncate

        public SFTPv3FileHandle createFileTruncate​(java.lang.String fileName)
                                    throws java.io.IOException
        Create a file (truncate it if it already exists) and open it for reading and writing. Same as createFileTruncate(fileName, null).
        Parameters:
        fileName - See the comment for the class for more details.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • createFileTruncate

        public SFTPv3FileHandle createFileTruncate​(java.lang.String fileName,
                                           SFTPv3FileAttributes attr)
                                    throws java.io.IOException
        reate a file (truncate it if it already exists) and open it for reading and writing. You can specify the default attributes of the file (the server may or may not respect your wishes).
        Parameters:
        fileName - See the comment for the class for more details.
        attr - may be null to use server defaults. Probably only the uid, gid and permissions (remember the server may apply a umask) entries of the SFTPv3FileHandle structure make sense. You need only to set those fields where you want to override the server's defaults.
        Returns:
        a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • read

        public int read​(SFTPv3FileHandle handle,
                long fileOffset,
                byte[] dst,
                int dstoff,
                int len)
         throws java.io.IOException
        Read bytes from a file. No more than 32768 bytes may be read at once. Be aware that the semantics of read() are different than for Java streams.

        • The server will read as many bytes as it can from the file (up to len), and return them.
        • If EOF is encountered before reading any data, -1 is returned.
        • If an error occurs, an exception is thrown
          • .
        • For normal disk files, it is guaranteed that the server will return the specified number of bytes, or up to end of file. For, e.g., device files this may return fewer bytes than requested.
        Parameters:
        handle - a SFTPv3FileHandle handle
        fileOffset - offset (in bytes) in the file
        dst - the destination byte array
        dstoff - offset in the destination byte array
        len - how many bytes to read, 0 < len <= 32768 bytes
        Returns:
        the number of bytes that could be read, may be less than requested if the end of the file is reached, -1 is returned in case of EOF
        Throws:
        java.io.IOException

      • write

        public void write​(SFTPv3FileHandle handle,
                  long fileOffset,
                  byte[] src,
                  int srcoff,
                  int len)
           throws java.io.IOException
        Write bytes to a file. If len > 32768, then the write operation will be split into multiple writes.
        Parameters:
        handle - a SFTPv3FileHandle handle.
        fileOffset - offset (in bytes) in the file.
        src - the source byte array.
        srcoff - offset in the source byte array.
        len - how many bytes to write.
        Throws:
        java.io.IOException

      • closeFile

        public void closeFile​(SFTPv3FileHandle handle)
               throws java.io.IOException
        Close a file.
        Parameters:
        handle - a SFTPv3FileHandle handle
        Throws:
        java.io.IOException

      • exists

        public boolean exists​(java.lang.String path)
               throws java.io.IOException
        Checks if the given path exists.
        Throws:
        java.io.IOException

      • _stat

        public SFTPv3FileAttributes _stat​(java.lang.String path)
                           throws java.io.IOException
        Graceful stat(String) that returns null if the path doesn't exist.
        Throws:
        java.io.IOException

      • mkdirs

        public void mkdirs​(java.lang.String path,
                   int posixPermission)
            throws java.io.IOException
        Makes sure that the directory exists, by creating it if necessary.
        Throws:
        java.io.IOException

      • writeToFile

        public java.io.OutputStream writeToFile​(java.lang.String path)
                                 throws java.io.IOException
        Creates a new file and writes to it.
        Throws:
        java.io.IOException

      • read

        public java.io.InputStream read​(java.lang.String file)
                         throws java.io.IOException
        Throws:
        java.io.IOException

      • chmod

        public void chmod​(java.lang.String path,
                  int permissions)
           throws java.io.IOException
        Throws:
        java.io.IOException