Needed for salmon which seems to have a fixation with forcing you to encode/decode ASN.1. Sick.

author: Mike Macgirvin <mike@macgirvin.com> 2010-10-07 02:53:31 -0700
committer: Mike Macgirvin <mike@macgirvin.com> 2010-10-07 02:53:31 -0700
commit: 4daed0a009645377596fcf495a64edb32ee2245e (patch)
tree: 072a695c28c96f33fcaad581c96f224da8e49efd /phpsec/Net
parent: 9c10ada9060c9745f49652469e172be8152f6cad (diff)
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volse-hubzilla-4daed0a009645377596fcf495a64edb32ee2245e.tar.bz2
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3 files changed, 4923 insertions, 0 deletions
diff --git a/phpsec/Net/SFTP.php b/phpsec/Net/SFTP.php
new file mode 100644
index 000000000..06812ada3
--- /dev/null
+++ b/phpsec/Net/SFTP.php
@@ -0,0 +1,1461 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of SFTP.
+ *
+ * PHP versions 4 and 5
+ *
+ * Currently only supports SFTPv3, which, according to wikipedia.org, "is the most widely used version,
+ * implemented by the popular OpenSSH SFTP server".  If you want SFTPv4/5/6 support, provide me with access
+ * to an SFTPv4/5/6 server.
+ *
+ * The API for this library is modeled after the API from PHP's {@link http://php.net/book.ftp FTP extension}.
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Net/SFTP.php');
+ *
+ *    $sftp = new Net_SFTP('www.domain.tld');
+ *    if (!$sftp->login('username', 'password')) {
+ *        exit('Login Failed');
+ *    }
+ *
+ *    echo $sftp->pwd() . "\r\n";
+ *    $sftp->put('filename.ext', 'hello, world!');
+ *    print_r($sftp->nlist());
+ * ?>
+ * </code>
+ *
+ * LICENSE: This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA  02111-1307  USA
+ *
+ * @category   Net
+ * @package    Net_SFTP
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMIX Jim Wigginton
+ * @license    http://www.gnu.org/licenses/lgpl.txt
+ * @version    $Id: SFTP.php,v 1.21 2010/04/09 02:31:34 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Net_SSH2
+ */
+require_once('Net/SSH2.php');
+
+/**#@+
+ * @access public
+ * @see Net_SFTP::getLog()
+ */
+/**
+ * Returns the message numbers
+ */
+define('NET_SFTP_LOG_SIMPLE',  NET_SSH2_LOG_SIMPLE);
+/**
+ * Returns the message content
+ */
+define('NET_SFTP_LOG_COMPLEX', NET_SSH2_LOG_COMPLEX);
+/**#@-*/
+
+/**
+ * SFTP channel constant
+ *
+ * Net_SSH2::exec() uses 0 and Net_SSH2::interactiveRead() / Net_SSH2::interactiveWrite() use 1.
+ *
+ * @see Net_SSH2::_send_channel_packet()
+ * @see Net_SSH2::_get_channel_packet()
+ * @access private
+ */
+define('NET_SFTP_CHANNEL', 2);
+
+/**#@+
+ * @access public
+ * @see Net_SFTP::put()
+ */
+/**
+ * Reads data from a local file.
+ */
+define('NET_SFTP_LOCAL_FILE', 1);
+/**
+ * Reads data from a string.
+ */
+define('NET_SFTP_STRING',  2);
+/**#@-*/
+
+/**
+ * Pure-PHP implementations of SFTP.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Net_SFTP
+ */
+class Net_SFTP extends Net_SSH2 {
+    /**
+     * Packet Types
+     *
+     * @see Net_SFTP::Net_SFTP()
+     * @var Array
+     * @access private
+     */
+    var $packet_types = array();
+
+    /**
+     * Status Codes
+     *
+     * @see Net_SFTP::Net_SFTP()
+     * @var Array
+     * @access private
+     */
+    var $status_codes = array();
+
+    /**
+     * The Request ID
+     *
+     * The request ID exists in the off chance that a packet is sent out-of-order.  Of course, this library doesn't support
+     * concurrent actions, so it's somewhat academic, here.
+     *
+     * @var Integer
+     * @see Net_SFTP::_send_sftp_packet()
+     * @access private
+     */
+    var $request_id = false;
+
+    /**
+     * The Packet Type
+     *
+     * The request ID exists in the off chance that a packet is sent out-of-order.  Of course, this library doesn't support
+     * concurrent actions, so it's somewhat academic, here.
+     *
+     * @var Integer
+     * @see Net_SFTP::_get_sftp_packet()
+     * @access private
+     */
+    var $packet_type = -1;
+
+    /**
+     * Packet Buffer
+     *
+     * @var String
+     * @see Net_SFTP::_get_sftp_packet()
+     * @access private
+     */
+    var $packet_buffer = '';
+
+    /**
+     * Extensions supported by the server
+     *
+     * @var Array
+     * @see Net_SFTP::_initChannel()
+     * @access private
+     */
+    var $extensions = array();
+
+    /**
+     * Server SFTP version
+     *
+     * @var Integer
+     * @see Net_SFTP::_initChannel()
+     * @access private
+     */
+    var $version;
+
+    /**
+     * Current working directory
+     *
+     * @var String
+     * @see Net_SFTP::_realpath()
+     * @see Net_SFTP::chdir()
+     * @access private
+     */
+    var $pwd = false;
+
+    /**
+     * Packet Type Log
+     *
+     * @see Net_SFTP::getLog()
+     * @var Array
+     * @access private
+     */
+    var $packet_type_log = array();
+
+    /**
+     * Packet Log
+     *
+     * @see Net_SFTP::getLog()
+     * @var Array
+     * @access private
+     */
+    var $packet_log = array();
+
+    /**
+     * Error information
+     *
+     * @see Net_SFTP::getSFTPErrors()
+     * @see Net_SFTP::getLastSFTPError()
+     * @var String
+     * @access private
+     */
+    var $errors = array();
+
+    /**
+     * Default Constructor.
+     *
+     * Connects to an SFTP server
+     *
+     * @param String $host
+     * @param optional Integer $port
+     * @param optional Integer $timeout
+     * @return Net_SFTP
+     * @access public
+     */
+    function Net_SFTP($host, $port = 22, $timeout = 10)
+    {
+        parent::Net_SSH2($host, $port, $timeout);
+        $this->packet_types = array(
+            1  => 'NET_SFTP_INIT',
+            2  => 'NET_SFTP_VERSION',
+            /* the format of SSH_FXP_OPEN changed between SFTPv4 and SFTPv5+:
+                   SFTPv5+: http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.1.1
+               pre-SFTPv5 : http://tools.ietf.org/html/draft-ietf-secsh-filexfer-04#section-6.3 */
+            3  => 'NET_SFTP_OPEN',
+            4  => 'NET_SFTP_CLOSE',
+            5  => 'NET_SFTP_READ',
+            6  => 'NET_SFTP_WRITE',
+            8  => 'NET_SFTP_FSTAT',
+            9  => 'NET_SFTP_SETSTAT',
+            11 => 'NET_SFTP_OPENDIR',
+            12 => 'NET_SFTP_READDIR',
+            13 => 'NET_SFTP_REMOVE',
+            14 => 'NET_SFTP_MKDIR',
+            15 => 'NET_SFTP_RMDIR',
+            16 => 'NET_SFTP_REALPATH',
+            17 => 'NET_SFTP_STAT',
+            /* the format of SSH_FXP_RENAME changed between SFTPv4 and SFTPv5+:
+                   SFTPv5+: http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.3
+               pre-SFTPv5 : http://tools.ietf.org/html/draft-ietf-secsh-filexfer-04#section-6.5 */
+            18 => 'NET_SFTP_RENAME',
+
+            101=> 'NET_SFTP_STATUS',
+            102=> 'NET_SFTP_HANDLE',
+            /* the format of SSH_FXP_NAME changed between SFTPv3 and SFTPv4+:
+                   SFTPv4+: http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-9.4
+               pre-SFTPv4 : http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02#section-7 */
+            103=> 'NET_SFTP_DATA',
+            104=> 'NET_SFTP_NAME',
+            105=> 'NET_SFTP_ATTRS',
+
+            200=> 'NET_SFTP_EXTENDED'
+        );
+        $this->status_codes = array(
+            0 => 'NET_SFTP_STATUS_OK',
+            1 => 'NET_SFTP_STATUS_EOF',
+            2 => 'NET_SFTP_STATUS_NO_SUCH_FILE',
+            3 => 'NET_SFTP_STATUS_PERMISSION_DENIED',
+            4 => 'NET_SFTP_STATUS_FAILURE',
+            5 => 'NET_SFTP_STATUS_BAD_MESSAGE',
+            6 => 'NET_SFTP_STATUS_NO_CONNECTION',
+            7 => 'NET_SFTP_STATUS_CONNECTION_LOST',
+            8 => 'NET_SFTP_STATUS_OP_UNSUPPORTED'
+        );
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-7.1
+        // the order, in this case, matters quite a lot - see Net_SFTP::_parseAttributes() to understand why
+        $this->attributes = array(
+            0x00000001 => 'NET_SFTP_ATTR_SIZE',
+            0x00000002 => 'NET_SFTP_ATTR_UIDGID', // defined in SFTPv3, removed in SFTPv4+
+            0x00000004 => 'NET_SFTP_ATTR_PERMISSIONS',
+            0x00000008 => 'NET_SFTP_ATTR_ACCESSTIME',
+                    -1 => 'NET_SFTP_ATTR_EXTENDED' // unpack('N', "\xFF\xFF\xFF\xFF") == array(1 => int(-1))
+        );
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-04#section-6.3
+        // the flag definitions change somewhat in SFTPv5+.  if SFTPv5+ support is added to this library, maybe name
+        // the array for that $this->open5_flags and similarily alter the constant names.
+        $this->open_flags = array(
+            0x00000001 => 'NET_SFTP_OPEN_READ',
+            0x00000002 => 'NET_SFTP_OPEN_WRITE',
+            0x00000008 => 'NET_SFTP_OPEN_CREATE',
+            0x00000010 => 'NET_SFTP_OPEN_TRUNCATE'
+        );
+        $this->_define_array(
+            $this->packet_types,
+            $this->status_codes,
+            $this->attributes,
+            $this->open_flags
+        );
+    }
+
+    /**
+     * Login
+     *
+     * @param String $username
+     * @param optional String $password
+     * @return Boolean
+     * @access public
+     */
+    function login($username, $password = '')
+    {
+        if (!parent::login($username, $password)) {
+            return false;
+        }
+
+        $this->window_size_client_to_server[NET_SFTP_CHANNEL] = $this->window_size;
+
+        $packet = pack('CNa*N3',
+            NET_SSH2_MSG_CHANNEL_OPEN, strlen('session'), 'session', NET_SFTP_CHANNEL, $this->window_size, 0x4000);
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $this->channel_status[NET_SFTP_CHANNEL] = NET_SSH2_MSG_CHANNEL_OPEN;
+
+        $response = $this->_get_channel_packet(NET_SFTP_CHANNEL);
+        if ($response === false) {
+            return false;
+        }
+
+        $packet = pack('CNNa*CNa*',
+            NET_SSH2_MSG_CHANNEL_REQUEST, $this->server_channels[NET_SFTP_CHANNEL], strlen('subsystem'), 'subsystem', 1, strlen('sftp'), 'sftp');
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $this->channel_status[NET_SFTP_CHANNEL] = NET_SSH2_MSG_CHANNEL_REQUEST;
+
+        $response = $this->_get_channel_packet(NET_SFTP_CHANNEL);
+        if ($response === false) {
+            return false;
+        }
+
+        $this->channel_status[NET_SFTP_CHANNEL] = NET_SSH2_MSG_CHANNEL_DATA;
+
+        if (!$this->_send_sftp_packet(NET_SFTP_INIT, "\0\0\0\3")) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_VERSION) {
+            user_error('Expected SSH_FXP_VERSION', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nversion', $this->_string_shift($response, 4)));
+        $this->version = $version;
+        while (!empty($response)) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $key = $this->_string_shift($response, $length);
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $value = $this->_string_shift($response, $length);
+            $this->extensions[$key] = $value;
+        }
+
+        /*
+         SFTPv4+ defines a 'newline' extension.  SFTPv3 seems to have unofficial support for it via 'newline@vandyke.com',
+         however, I'm not sure what 'newline@vandyke.com' is supposed to do (the fact that it's unofficial means that it's
+         not in the official SFTPv3 specs) and 'newline@vandyke.com' / 'newline' are likely not drop-in substitutes for
+         one another due to the fact that 'newline' comes with a SSH_FXF_TEXT bitmask whereas it seems unlikely that
+         'newline@vandyke.com' would.
+        */
+        /*
+        if (isset($this->extensions['newline@vandyke.com'])) {
+            $this->extensions['newline'] = $this->extensions['newline@vandyke.com'];
+            unset($this->extensions['newline@vandyke.com']);
+        }
+        */
+
+        $this->request_id = 1;
+
+        /*
+         A Note on SFTPv4/5/6 support:
+         <http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-5.1> states the following:
+
+         "If the client wishes to interoperate with servers that support noncontiguous version
+          numbers it SHOULD send '3'"
+
+         Given that the server only sends its version number after the client has already done so, the above
+         seems to be suggesting that v3 should be the default version.  This makes sense given that v3 is the
+         most popular.
+
+         <http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-5.5> states the following;
+
+         "If the server did not send the "versions" extension, or the version-from-list was not included, the
+          server MAY send a status response describing the failure, but MUST then close the channel without
+          processing any further requests."
+
+         So what do you do if you have a client whose initial SSH_FXP_INIT packet says it implements v3 and
+         a server whose initial SSH_FXP_VERSION reply says it implements v4 and only v4?  If it only implements
+         v4, the "versions" extension is likely not going to have been sent so version re-negotiation as discussed
+         in draft-ietf-secsh-filexfer-13 would be quite impossible.  As such, what Net_SFTP would do is close the
+         channel and reopen it with a new and updated SSH_FXP_INIT packet.
+        */
+        if ($this->version != 3) {
+            return false;
+        }
+
+        $this->pwd = $this->_realpath('.');
+
+        return true;
+    }
+
+    /**
+     * Returns the current directory name
+     *
+     * @return Mixed
+     * @access public
+     */
+    function pwd()
+    {
+        return $this->pwd;
+    }
+
+    /**
+     * Canonicalize the Server-Side Path Name
+     *
+     * SFTP doesn't provide a mechanism by which the current working directory can be changed, so we'll emulate it.  Returns
+     * the absolute (canonicalized) path.  If $mode is set to NET_SFTP_CONFIRM_DIR (as opposed to NET_SFTP_CONFIRM_NONE,
+     * which is what it is set to by default), false is returned if $dir is not a valid directory.
+     *
+     * @see Net_SFTP::chdir()
+     * @param String $dir
+     * @param optional Integer $mode
+     * @return Mixed
+     * @access private
+     */
+    function _realpath($dir)
+    {
+        /*
+        "This protocol 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).  Note
+         that identifying the user is assumed to take place outside of this
+         protocol."
+
+         -- http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-6
+        */
+        $file = '';
+        if ($this->pwd !== false) {
+            // if the SFTP server returned the canonicalized path even for non-existant files this wouldn't be necessary
+            // on OpenSSH it isn't necessary but on other SFTP servers it is.  that and since the specs say nothing on
+            // the subject, we'll go ahead and work around it with the following.
+            if ($dir[strlen($dir) - 1] != '/') {
+                $file = basename($dir);
+                $dir = dirname($dir);
+            }
+
+            if ($dir == '.' || $dir == $this->pwd) {
+                return $this->pwd . $file;
+            }
+
+            if ($dir[0] != '/') {
+                $dir = $this->pwd . '/' . $dir;
+            }
+            // on the surface it seems like maybe resolving a path beginning with / is unnecessary, but such paths
+            // can contain .'s and ..'s just like any other.  we could parse those out as appropriate or we can let
+            // the server do it.  we'll do the latter.
+        }
+
+        /*
+         that SSH_FXP_REALPATH returns SSH_FXP_NAME does not necessarily mean that anything actually exists at the
+         specified path.  generally speaking, no attributes are returned with this particular SSH_FXP_NAME packet
+         regardless of whether or not a file actually exists.  and in SFTPv3, the longname field and the filename
+         field match for this particular SSH_FXP_NAME packet.  for other SSH_FXP_NAME packets, this will likely
+         not be the case, but for this one, it is.
+        */
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.9
+        if (!$this->_send_sftp_packet(NET_SFTP_REALPATH, pack('Na*', strlen($dir), $dir))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_NAME:
+                // although SSH_FXP_NAME is implemented differently in SFTPv3 than it is in SFTPv4+, the following
+                // should work on all SFTP versions since the only part of the SSH_FXP_NAME packet the following looks
+                // at is the first part and that part is defined the same in SFTP versions 3 through 6.
+                $this->_string_shift($response, 4); // skip over the count - it should be 1, anyway
+                extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                $realpath = $this->_string_shift($response, $length);
+                break;
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        // if $this->pwd isn't set than the only thing $realpath could be is for '.', which is pretty much guaranteed to
+        // be a bonafide directory
+        return $realpath . '/' . $file;
+    }
+
+    /**
+     * Changes the current directory
+     *
+     * @param String $dir
+     * @return Boolean
+     * @access public
+     */
+    function chdir($dir)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        if ($dir[strlen($dir) - 1] != '/') {
+            $dir.= '/';
+        }
+        $dir = $this->_realpath($dir);
+
+        // confirm that $dir is, in fact, a valid directory
+        if (!$this->_send_sftp_packet(NET_SFTP_OPENDIR, pack('Na*', strlen($dir), $dir))) {
+            return false;
+        }
+
+        // see Net_SFTP::nlist() for a more thorough explanation of the following
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                $handle = substr($response, 4);
+                break;
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        if (!$this->_send_sftp_packet(NET_SFTP_CLOSE, pack('Na*', strlen($handle), $handle))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        $this->pwd = $dir;
+        return true;
+    }
+
+    /**
+     * Returns a list of files in the given directory
+     *
+     * @param optional String $dir
+     * @return Mixed
+     * @access public
+     */
+    function nlist($dir = '.')
+    {
+        return $this->_list($dir, false);
+    }
+
+    /**
+     * Returns a list of files in the given directory
+     *
+     * @param optional String $dir
+     * @return Mixed
+     * @access public
+     */
+    function rawlist($dir = '.')
+    {
+        return $this->_list($dir, true);
+    }
+
+    function _list($dir, $raw = true)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $dir = $this->_realpath($dir);
+        if ($dir === false) {
+            return false;
+        }
+
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.1.2
+        if (!$this->_send_sftp_packet(NET_SFTP_OPENDIR, pack('Na*', strlen($dir), $dir))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-9.2
+                // since 'handle' is the last field in the SSH_FXP_HANDLE packet, we'll just remove the first four bytes that
+                // represent the length of the string and leave it at that
+                $handle = substr($response, 4);
+                break;
+            case NET_SFTP_STATUS:
+                // presumably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        $contents = array();
+        while (true) {
+            // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.2.2
+            // why multiple SSH_FXP_READDIR packets would be sent when the response to a single one can span arbitrarily many
+            // SSH_MSG_CHANNEL_DATA messages is not known to me.
+            if (!$this->_send_sftp_packet(NET_SFTP_READDIR, pack('Na*', strlen($handle), $handle))) {
+                return false;
+            }
+
+            $response = $this->_get_sftp_packet();
+            switch ($this->packet_type) {
+                case NET_SFTP_NAME:
+                    extract(unpack('Ncount', $this->_string_shift($response, 4)));
+                    for ($i = 0; $i < $count; $i++) {
+                        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                        $shortname = $this->_string_shift($response, $length);
+                        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                        $this->_string_shift($response, $length); // SFTPv4+ drop this field - the "longname" field
+                        $attributes = $this->_parseAttributes($response); // we also don't care about the attributes
+                        if (!$raw) {
+                            $contents[] = $shortname;
+                        } else {
+                            $contents[$shortname] = $attributes;
+                        }
+                        // SFTPv6 has an optional boolean end-of-list field, but we'll ignore that, since the
+                        // final SSH_FXP_STATUS packet should tell us that, already.
+                    }
+                    break;
+                case NET_SFTP_STATUS:
+                    extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+                    if ($status != NET_SFTP_STATUS_EOF) {
+                        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                        $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                        return false;
+                    }
+                    break 2;
+                default:
+                    user_error('Expected SSH_FXP_NAME or SSH_FXP_STATUS', E_USER_NOTICE);
+                    return false;
+            }
+        }
+
+        if (!$this->_send_sftp_packet(NET_SFTP_CLOSE, pack('Na*', strlen($handle), $handle))) {
+            return false;
+        }
+
+        // "The client MUST release all resources associated with the handle regardless of the status."
+        //  -- http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.1.3
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return $contents;
+    }
+
+    /**
+     * Returns the file size, in bytes, or false, on failure
+     *
+     * Files larger than 4GB will show up as being exactly 4GB.
+     *
+     * @param optional String $dir
+     * @return Mixed
+     * @access public
+     */
+    function size($filename)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $filename = $this->_realpath($filename);
+        if ($filename === false) {
+            return false;
+        }
+
+        // SFTPv4+ adds an additional 32-bit integer field - flags - to the following:
+        $packet = pack('Na*', strlen($filename), $filename);
+        if (!$this->_send_sftp_packet(NET_SFTP_STAT, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_ATTRS:
+                $attrs = $this->_parseAttributes($response);
+                return $attrs['size'];
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+        }
+
+        user_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS', E_USER_NOTICE);
+        return false;
+    }
+
+    /**
+     * Set permissions on a file.
+     *
+     * Returns the new file permissions on success or FALSE on error.
+     *
+     * @param Integer $mode
+     * @param String $filename
+     * @return Mixed
+     * @access public
+     */
+    function chmod($mode, $filename)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $filename = $this->_realpath($filename);
+        if ($filename === false) {
+            return false;
+        }
+
+        // SFTPv4+ has an additional byte field - type - that would need to be sent, as well. setting it to
+        // SSH_FILEXFER_TYPE_UNKNOWN might work. if not, we'd have to do an SSH_FXP_STAT before doing an SSH_FXP_SETSTAT.
+        $attr = pack('N2', NET_SFTP_ATTR_PERMISSIONS, $mode & 07777);
+        if (!$this->_send_sftp_packet(NET_SFTP_SETSTAT, pack('Na*a*', strlen($filename), $filename, $attr))) {
+            return false;
+        }
+
+        /*
+         "Because some systems must use separate system calls to set various attributes, it is possible that a failure 
+          response will be returned, but yet some of the attributes may be have been successfully modified.  If possible,
+          servers SHOULD avoid this situation; however, clients MUST be aware that this is possible."
+
+          -- http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.6
+        */
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_EOF) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+        }
+
+        // rather than return what the permissions *should* be, we'll return what they actually are.  this will also
+        // tell us if the file actually exists.
+        // incidentally, SFTPv4+ adds an additional 32-bit integer field - flags - to the following:
+        $packet = pack('Na*', strlen($filename), $filename);
+        if (!$this->_send_sftp_packet(NET_SFTP_STAT, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_ATTRS:
+                $attrs = $this->_parseAttributes($response);
+                return $attrs['permissions'];
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+        }
+
+        user_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS', E_USER_NOTICE);
+        return false;
+    }
+
+    /**
+     * Creates a directory.
+     *
+     * @param String $dir
+     * @return Boolean
+     * @access public
+     */
+    function mkdir($dir)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $dir = $this->_realpath(rtrim($dir, '/'));
+        if ($dir === false) {
+            return false;
+        }
+
+        // by not providing any permissions, hopefully the server will use the logged in users umask - their 
+        // default permissions.
+        if (!$this->_send_sftp_packet(NET_SFTP_MKDIR, pack('Na*N', strlen($dir), $dir, 0))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Removes a directory.
+     *
+     * @param String $dir
+     * @return Boolean
+     * @access public
+     */
+    function rmdir($dir)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $dir = $this->_realpath($dir);
+        if ($dir === false) {
+            return false;
+        }
+
+        if (!$this->_send_sftp_packet(NET_SFTP_RMDIR, pack('Na*', strlen($dir), $dir))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            // presumably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED?
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Uploads a file to the SFTP server.
+     *
+     * By default, Net_SFTP::put() does not read from the local filesystem.  $data is dumped directly into $remote_file.
+     * So, for example, if you set $data to 'filename.ext' and then do Net_SFTP::get(), you will get a file, twelve bytes
+     * long, containing 'filename.ext' as its contents.
+     *
+     * Setting $mode to NET_SFTP_LOCAL_FILE will change the above behavior.  With NET_SFTP_LOCAL_FILE, $remote_file will 
+     * contain as many bytes as filename.ext does on your local filesystem.  If your filename.ext is 1MB then that is how
+     * large $remote_file will be, as well.
+     *
+     * Currently, only binary mode is supported.  As such, if the line endings need to be adjusted, you will need to take
+     * care of that, yourself.
+     *
+     * @param String $remote_file
+     * @param String $data
+     * @param optional Integer $flags
+     * @return Boolean
+     * @access public
+     * @internal ASCII mode for SFTPv4/5/6 can be supported by adding a new function - Net_SFTP::setMode().
+     */
+    function put($remote_file, $data, $mode = NET_SFTP_STRING)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $remote_file = $this->_realpath($remote_file);
+        if ($remote_file === false) {
+            return false;
+        }
+
+        $packet = pack('Na*N2', strlen($remote_file), $remote_file, NET_SFTP_OPEN_WRITE | NET_SFTP_OPEN_CREATE | NET_SFTP_OPEN_TRUNCATE, 0);
+        if (!$this->_send_sftp_packet(NET_SFTP_OPEN, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                $handle = substr($response, 4);
+                break;
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        $initialize = true;
+
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.2.3
+        if ($mode == NET_SFTP_LOCAL_FILE) {
+            if (!is_file($data)) {
+                user_error("$data is not a valid file", E_USER_NOTICE);
+                return false;
+            }
+            $fp = fopen($data, 'rb');
+            if (!$fp) {
+                return false;
+            }
+            $sent = 0;
+            $size = filesize($data);
+        } else {
+            $sent = 0;
+            $size = strlen($data);
+        }
+
+        $size = $size < 0 ? ($size & 0x7FFFFFFF) + 0x80000000 : $size;
+
+        $sftp_packet_size = 34000; // PuTTY uses 4096
+        $i = 0;
+        while ($sent < $size) {
+            $temp = $mode == NET_SFTP_LOCAL_FILE ? fread($fp, $sftp_packet_size) : $this->_string_shift($data, $sftp_packet_size);
+            $packet = pack('Na*N3a*', strlen($handle), $handle, 0, $sent, strlen($temp), $temp);
+            if (!$this->_send_sftp_packet(NET_SFTP_WRITE, $packet)) {
+                fclose($fp);
+                return false;
+            }
+            $sent+= strlen($temp);
+
+            $i++;
+
+            if ($i == 50) {
+                if (!$this->_read_put_responses($i)) {
+                    $i = 0;
+                    break;
+                }
+                $i = 0;
+            }
+        }
+
+        $this->_read_put_responses($i);
+
+        if ($mode == NET_SFTP_LOCAL_FILE) {
+            fclose($fp);
+        }
+
+        if (!$this->_send_sftp_packet(NET_SFTP_CLOSE, pack('Na*', strlen($handle), $handle))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Reads multiple successive SSH_FXP_WRITE responses
+     *
+     * Sending an SSH_FXP_WRITE packet and immediately reading its response isn't as efficient as blindly sending out $i
+     * SSH_FXP_WRITEs, in succession, and then reading $i responses.
+     *
+     * @param Integer $i
+     * @return Boolean
+     * @access private
+     */
+    function _read_put_responses($i)
+    {
+        while ($i--) {
+            $response = $this->_get_sftp_packet();
+            if ($this->packet_type != NET_SFTP_STATUS) {
+                user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+            }
+
+            extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+            if ($status != NET_SFTP_STATUS_OK) {
+                extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                break;
+            }
+        }
+
+        return $i < 0;
+    }
+
+    /**
+     * Downloads a file from the SFTP server.
+     *
+     * Returns a string containing the contents of $remote_file if $local_file is left undefined or a boolean false if
+     * the operation was unsuccessful.  If $local_file is defined, returns true or false depending on the success of the
+     * operation
+     *
+     * @param String $remote_file
+     * @param optional String $local_file
+     * @return Mixed
+     * @access public
+     */
+    function get($remote_file, $local_file = false)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $remote_file = $this->_realpath($remote_file);
+        if ($remote_file === false) {
+            return false;
+        }
+
+        $packet = pack('Na*N2', strlen($remote_file), $remote_file, NET_SFTP_OPEN_READ, 0);
+        if (!$this->_send_sftp_packet(NET_SFTP_OPEN, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_HANDLE:
+                $handle = substr($response, 4);
+                break;
+            case NET_SFTP_STATUS: // presumably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_HANDLE or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        $packet = pack('Na*', strlen($handle), $handle);
+        if (!$this->_send_sftp_packet(NET_SFTP_FSTAT, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        switch ($this->packet_type) {
+            case NET_SFTP_ATTRS:
+                $attrs = $this->_parseAttributes($response);
+                break;
+            case NET_SFTP_STATUS:
+                extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                return false;
+            default:
+                user_error('Expected SSH_FXP_ATTRS or SSH_FXP_STATUS', E_USER_NOTICE);
+                return false;
+        }
+
+        if ($local_file !== false) {
+            $fp = fopen($local_file, 'wb');
+            if (!$fp) {
+                return false;
+            }
+        } else {
+            $content = '';
+        }
+
+        $read = 0;
+        while ($read < $attrs['size']) {
+            $packet = pack('Na*N3', strlen($handle), $handle, 0, $read, 1 << 20);
+            if (!$this->_send_sftp_packet(NET_SFTP_READ, $packet)) {
+                return false;
+            }
+
+            $response = $this->_get_sftp_packet();
+            switch ($this->packet_type) {
+                case NET_SFTP_DATA:
+                    $temp = substr($response, 4);
+                    $read+= strlen($temp);
+                    if ($local_file === false) {
+                        $content.= $temp;
+                    } else {
+                        fputs($fp, $temp);
+                    }
+                    break;
+                case NET_SFTP_STATUS:
+                    extract(unpack('Nstatus/Nlength', $this->_string_shift($response, 8)));
+                    $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+                    break 2;
+                default:
+                    user_error('Expected SSH_FXP_DATA or SSH_FXP_STATUS', E_USER_NOTICE);
+                    return false;
+            }
+        }
+
+        if (!$this->_send_sftp_packet(NET_SFTP_CLOSE, pack('Na*', strlen($handle), $handle))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        if (isset($content)) {
+            return $content;
+        }
+
+        fclose($fp);
+        return true;
+    }
+
+    /**
+     * Deletes a file on the SFTP server.
+     *
+     * @param String $path
+     * @return Boolean
+     * @access public
+     */
+    function delete($path)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $remote_file = $this->_realpath($path);
+        if ($path === false) {
+            return false;
+        }
+
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.3
+        if (!$this->_send_sftp_packet(NET_SFTP_REMOVE, pack('Na*', strlen($path), $path))) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        // if $status isn't SSH_FX_OK it's probably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Renames a file or a directory on the SFTP server
+     *
+     * @param String $oldname
+     * @param String $newname
+     * @return Boolean
+     * @access public
+     */
+    function rename($oldname, $newname)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        $oldname = $this->_realpath($oldname);
+        $newname = $this->_realpath($newname);
+        if ($oldname === false || $newname === false) {
+            return false;
+        }
+
+        // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.3
+        $packet = pack('Na*Na*', strlen($oldname), $oldname, strlen($newname), $newname);
+        if (!$this->_send_sftp_packet(NET_SFTP_RENAME, $packet)) {
+            return false;
+        }
+
+        $response = $this->_get_sftp_packet();
+        if ($this->packet_type != NET_SFTP_STATUS) {
+            user_error('Expected SSH_FXP_STATUS', E_USER_NOTICE);
+            return false;
+        }
+
+        // if $status isn't SSH_FX_OK it's probably SSH_FX_NO_SUCH_FILE or SSH_FX_PERMISSION_DENIED
+        extract(unpack('Nstatus', $this->_string_shift($response, 4)));
+        if ($status != NET_SFTP_STATUS_OK) {
+            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            $this->sftp_errors[] = $this->status_codes[$status] . ': ' . $this->_string_shift($response, $length);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Parse Attributes
+     *
+     * See '7.  File Attributes' of draft-ietf-secsh-filexfer-13 for more info.
+     *
+     * @param String $response
+     * @return Array
+     * @access private
+     */
+    function _parseAttributes(&$response)
+    {
+        $attr = array();
+        extract(unpack('Nflags', $this->_string_shift($response, 4)));
+        // SFTPv4+ have a type field (a byte) that follows the above flag field
+        foreach ($this->attributes as $key => $value) {
+            switch ($flags & $key) {
+                case NET_SFTP_ATTR_SIZE: // 0x00000001
+                    // size is represented by a 64-bit integer, so we perhaps ought to be doing the following:
+                    // $attr['size'] = new Math_BigInteger($this->_string_shift($response, 8), 256);
+                    // of course, you shouldn't be using Net_SFTP to transfer files that are in excess of 4GB
+                    // (0xFFFFFFFF bytes), anyway.  as such, we'll just represent all file sizes that are bigger than
+                    // 4GB as being 4GB.
+                    extract(unpack('Nupper/Nsize', $this->_string_shift($response, 8)));
+                    if ($upper) {
+                        $attr['size'] = 0xFFFFFFFF;
+                    } else {
+                        $attr['size'] = $size < 0 ? ($size & 0x7FFFFFFF) + 0x80000000 : $size;
+                    }
+                    break;
+                case NET_SFTP_ATTR_UIDGID: // 0x00000002 (SFTPv3 only)
+                    $attr+= unpack('Nuid/Ngid', $this->_string_shift($response, 8));
+                    break;
+                case NET_SFTP_ATTR_PERMISSIONS: // 0x00000004
+                    $attr+= unpack('Npermissions', $this->_string_shift($response, 4));
+                    break;
+                case NET_SFTP_ATTR_ACCESSTIME: // 0x00000008
+                    $attr+= unpack('Natime/Nmtime', $this->_string_shift($response, 8));
+                    break;
+                case NET_SFTP_ATTR_EXTENDED: // 0x80000000
+                    extract(unpack('Ncount', $this->_string_shift($response, 4)));
+                    for ($i = 0; $i < $count; $i++) {
+                        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                        $key = $this->_string_shift($response, $length);
+                        extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                        $attr[$key] = $this->_string_shift($response, $length);                        
+                    }
+            }
+        }
+        return $attr;
+    }
+
+    /**
+     * Sends SFTP Packets
+     *
+     * See '6. General Packet Format' of draft-ietf-secsh-filexfer-13 for more info.
+     *
+     * @param Integer $type
+     * @param String $data
+     * @see Net_SFTP::_get_sftp_packet()
+     * @see Net_SSH2::_send_channel_packet()
+     * @return Boolean
+     * @access private
+     */
+    function _send_sftp_packet($type, $data)
+    {
+        $packet = $this->request_id !== false ?
+            pack('NCNa*', strlen($data) + 5, $type, $this->request_id, $data) :
+            pack('NCa*',  strlen($data) + 1, $type, $data);
+
+        $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
+        $result = $this->_send_channel_packet(NET_SFTP_CHANNEL, $packet);
+        $stop = strtok(microtime(), ' ') + strtok('');
+
+        if (defined('NET_SFTP_LOGGING')) {
+            $this->packet_type_log[] = '-> ' . $this->packet_types[$type] . 
+                                       ' (' . round($stop - $start, 4) . 's)';
+            if (NET_SFTP_LOGGING == NET_SFTP_LOG_COMPLEX) {
+                $this->packet_log[] = $data;
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Receives SFTP Packets
+     *
+     * See '6. General Packet Format' of draft-ietf-secsh-filexfer-13 for more info.
+     *
+     * Incidentally, the number of SSH_MSG_CHANNEL_DATA messages has no bearing on the number of SFTP packets present.
+     * There can be one SSH_MSG_CHANNEL_DATA messages containing two SFTP packets or there can be two SSH_MSG_CHANNEL_DATA
+     * messages containing one SFTP packet.
+     *
+     * @see Net_SFTP::_send_sftp_packet()
+     * @return String
+     * @access private
+     */
+    function _get_sftp_packet()
+    {
+        $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
+
+        // SFTP packet length
+        while (strlen($this->packet_buffer) < 4) {
+            $temp = $this->_get_channel_packet(NET_SFTP_CHANNEL);
+            if (is_bool($temp)) {
+                $this->packet_type = false;
+                $this->packet_buffer = '';
+                return false;
+            }
+            $this->packet_buffer.= $temp;
+        }
+        extract(unpack('Nlength', $this->_string_shift($this->packet_buffer, 4)));
+        $tempLength = $length;
+        $tempLength-= strlen($this->packet_buffer);
+
+        // SFTP packet type and data payload
+        while ($tempLength > 0) {
+            $temp = $this->_get_channel_packet(NET_SFTP_CHANNEL);
+            if (is_bool($temp)) {
+                $this->packet_type = false;
+                $this->packet_buffer = '';
+                return false;
+            }
+            $this->packet_buffer.= $temp;
+            $tempLength-= strlen($temp);
+        }
+
+        $stop = strtok(microtime(), ' ') + strtok('');
+
+        $this->packet_type = ord($this->_string_shift($this->packet_buffer));
+
+        if ($this->request_id !== false) {
+            $this->_string_shift($this->packet_buffer, 4); // remove the request id
+            $length-= 5; // account for the request id and the packet type
+        } else {
+            $length-= 1; // account for the packet type
+        }
+
+        $packet = $this->_string_shift($this->packet_buffer, $length);
+
+        if (defined('NET_SFTP_LOGGING')) {
+            $this->packet_type_log[] = '<- ' . $this->packet_types[$this->packet_type] . 
+                                       ' (' . round($stop - $start, 4) . 's)';
+            if (NET_SFTP_LOGGING == NET_SFTP_LOG_COMPLEX) {
+                $this->packet_log[] = $packet;
+            }
+        }
+
+        return $packet;
+    }
+
+    /**
+     * Returns a log of the packets that have been sent and received.
+     *
+     * Returns a string if NET_SFTP_LOGGING == NET_SFTP_LOG_COMPLEX, an array if NET_SFTP_LOGGING == NET_SFTP_LOG_SIMPLE and false if !defined('NET_SFTP_LOGGING')
+     *
+     * @access public
+     * @return String or Array
+     */
+    function getSFTPLog()
+    {
+        if (!defined('NET_SFTP_LOGGING')) {
+            return false;
+        }
+
+        switch (NET_SFTP_LOGGING) {
+            case NET_SFTP_LOG_COMPLEX:
+                return $this->_format_log($this->packet_log, $this->packet_type_log);
+                break;
+            //case NET_SFTP_LOG_SIMPLE:
+            default:
+                return $this->packet_type_log;
+        }
+    }
+
+    /**
+     * Returns all errors
+     *
+     * @return String
+     * @access public
+     */
+    function getSFTPErrors()
+    {
+        return $this->sftp_errors;
+    }
+
+    /**
+     * Returns the last error
+     *
+     * @return String
+     * @access public
+     */
+    function getLastSFTPError()
+    {
+        return $this->sftp_errors[count($this->sftp_errors) - 1];
+    }
+
+    /**
+     * Get supported SFTP versions
+     *
+     * @return Array
+     * @access public
+     */
+    function getSupportedVersions()
+    {
+        $temp = array('version' => $this->version);
+        if (isset($this->extensions['versions'])) {
+            $temp['extensions'] = $this->extensions['versions'];
+        }
+        return $temp;
+    }
+
+    /**
+     * Disconnect
+     *
+     * @param Integer $reason
+     * @return Boolean
+     * @access private
+     */
+    function _disconnect($reason)
+    {
+        $this->pwd = false;
+        parent::_disconnect($reason);
+    }
+}
+\ No newline at end of file
diff --git a/phpsec/Net/SSH1.php b/phpsec/Net/SSH1.php
new file mode 100644
index 000000000..6986a8450
--- /dev/null
+++ b/phpsec/Net/SSH1.php
@@ -0,0 +1,1160 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of SSHv1.
+ *
+ * PHP versions 4 and 5
+ *
+ * Here's a short example of how to use this library:
+ * <code>
+ * <?php
+ *    include('Net/SSH1.php');
+ *
+ *    $ssh = new Net_SSH1('www.domain.tld');
+ *    if (!$ssh->login('username', 'password')) {
+ *        exit('Login Failed');
+ *    }
+ *
+ *    while (true) {
+ *        echo $ssh->interactiveRead();
+ *
+ *        $read = array(STDIN);
+ *        $write = $except = NULL;
+ *        if (stream_select($read, $write, $except, 0)) {
+ *            $ssh->interactiveWrite(fread(STDIN, 1));
+ *        }
+ *    }
+ * ?>
+ * </code>
+ *
+ * Here's another short example:
+ * <code>
+ * <?php
+ *    include('Net/SSH1.php');
+ *
+ *    $ssh = new Net_SSH1('www.domain.tld');
+ *    if (!$ssh->login('username', 'password')) {
+ *        exit('Login Failed');
+ *    }
+ *
+ *    echo $ssh->exec('ls -la');
+ * ?>
+ * </code>
+ *
+ * More information on the SSHv1 specification can be found by reading 
+ * {@link http://www.snailbook.com/docs/protocol-1.5.txt protocol-1.5.txt}.
+ *
+ * LICENSE: This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA  02111-1307  USA
+ *
+ * @category   Net
+ * @package    Net_SSH1
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.gnu.org/licenses/lgpl.txt
+ * @version    $Id: SSH1.php,v 1.15 2010/03/22 22:01:38 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Math_BigInteger
+ *
+ * Used to do RSA encryption.
+ */
+require_once('Math/BigInteger.php');
+
+/**
+ * Include Crypt_Null
+ */
+//require_once('Crypt/Null.php');
+
+/**
+ * Include Crypt_DES
+ */
+require_once('Crypt/DES.php');
+
+/**
+ * Include Crypt_TripleDES
+ */
+require_once('Crypt/TripleDES.php');
+
+/**
+ * Include Crypt_RC4
+ */
+require_once('Crypt/RC4.php');
+
+/**
+ * Include Crypt_Random
+ */
+require_once('Crypt/Random.php');
+
+/**#@+
+ * Protocol Flags
+ *
+ * @access private
+ */
+define('NET_SSH1_MSG_DISCONNECT',          1);
+define('NET_SSH1_SMSG_PUBLIC_KEY',         2);
+define('NET_SSH1_CMSG_SESSION_KEY',        3);
+define('NET_SSH1_CMSG_USER',               4);
+define('NET_SSH1_CMSG_AUTH_PASSWORD',      9);
+define('NET_SSH1_CMSG_REQUEST_PTY',       10);
+define('NET_SSH1_CMSG_EXEC_SHELL',        12);
+define('NET_SSH1_CMSG_EXEC_CMD',          13);
+define('NET_SSH1_SMSG_SUCCESS',           14);
+define('NET_SSH1_SMSG_FAILURE',           15);
+define('NET_SSH1_CMSG_STDIN_DATA',        16);
+define('NET_SSH1_SMSG_STDOUT_DATA',       17);
+define('NET_SSH1_SMSG_STDERR_DATA',       18);
+define('NET_SSH1_SMSG_EXITSTATUS',        20);
+define('NET_SSH1_CMSG_EXIT_CONFIRMATION', 33);
+/**#@-*/
+
+/**#@+
+ * Encryption Methods
+ *
+ * @see Net_SSH1::getSupportedCiphers()
+ * @access public
+ */
+/**
+ * No encryption
+ *
+ * Not supported.
+ */
+define('NET_SSH1_CIPHER_NONE',       0);
+/**
+ * IDEA in CFB mode
+ *
+ * Not supported.
+ */
+define('NET_SSH1_CIPHER_IDEA',       1);
+/**
+ * DES in CBC mode
+ */
+define('NET_SSH1_CIPHER_DES',        2);
+/**
+ * Triple-DES in CBC mode
+ *
+ * All implementations are required to support this
+ */
+define('NET_SSH1_CIPHER_3DES',       3);
+/**
+ * TRI's Simple Stream encryption CBC
+ *
+ * Not supported nor is it defined in the official SSH1 specs.  OpenSSH, however, does define it (see cipher.h),
+ * although it doesn't use it (see cipher.c)
+ */
+define('NET_SSH1_CIPHER_BROKEN_TSS', 4);
+/**
+ * RC4
+ *
+ * Not supported.
+ *
+ * @internal According to the SSH1 specs:
+ *
+ *        "The first 16 bytes of the session key are used as the key for
+ *         the server to client direction.  The remaining 16 bytes are used
+ *         as the key for the client to server direction.  This gives
+ *         independent 128-bit keys for each direction."
+ *
+ *     This library currently only supports encryption when the same key is being used for both directions.  This is
+ *     because there's only one $crypto object.  Two could be added ($encrypt and $decrypt, perhaps).
+ */
+define('NET_SSH1_CIPHER_RC4',        5);
+/**
+ * Blowfish
+ *
+ * Not supported nor is it defined in the official SSH1 specs.  OpenSSH, however, defines it (see cipher.h) and
+ * uses it (see cipher.c)
+ */
+define('NET_SSH1_CIPHER_BLOWFISH',   6);
+/**#@-*/
+
+/**#@+
+ * Authentication Methods
+ *
+ * @see Net_SSH1::getSupportedAuthentications()
+ * @access public
+ */
+/**
+ * .rhosts or /etc/hosts.equiv
+ */
+define('NET_SSH1_AUTH_RHOSTS',     1);
+/**
+ * pure RSA authentication
+ */
+define('NET_SSH1_AUTH_RSA',        2);
+/**
+ * password authentication
+ *
+ * This is the only method that is supported by this library.
+ */
+define('NET_SSH1_AUTH_PASSWORD',   3);
+/**
+ * .rhosts with RSA host authentication
+ */
+define('NET_SSH1_AUTH_RHOSTS_RSA', 4);
+/**#@-*/
+
+/**#@+
+ * Terminal Modes
+ *
+ * @link http://3sp.com/content/developer/maverick-net/docs/Maverick.SSH.PseudoTerminalModesMembers.html
+ * @access private
+ */
+define('NET_SSH1_TTY_OP_END',  0);
+/**#@-*/
+
+/**
+ * The Response Type
+ *
+ * @see Net_SSH1::_get_binary_packet()
+ * @access private
+ */
+define('NET_SSH1_RESPONSE_TYPE', 1);
+
+/**
+ * The Response Data
+ *
+ * @see Net_SSH1::_get_binary_packet()
+ * @access private
+ */
+define('NET_SSH1_RESPONSE_DATA', 2);
+
+/**#@+
+ * Execution Bitmap Masks
+ *
+ * @see Net_SSH1::bitmap
+ * @access private
+ */
+define('NET_SSH1_MASK_CONSTRUCTOR', 0x00000001);
+define('NET_SSH1_MASK_LOGIN',       0x00000002);
+define('NET_SSH1_MASK_SHELL',       0x00000004);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of SSHv1.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Net_SSH1
+ */
+class Net_SSH1 {
+    /**
+     * The SSH identifier
+     *
+     * @var String
+     * @access private
+     */
+    var $identifier = 'SSH-1.5-phpseclib';
+
+    /**
+     * The Socket Object
+     *
+     * @var Object
+     * @access private
+     */
+    var $fsock;
+
+    /**
+     * The cryptography object
+     *
+     * @var Object
+     * @access private
+     */
+    var $crypto = false;
+
+    /**
+     * Execution Bitmap
+     *
+     * The bits that are set reprsent functions that have been called already.  This is used to determine
+     * if a requisite function has been successfully executed.  If not, an error should be thrown.
+     *
+     * @var Integer
+     * @access private
+     */
+    var $bitmap = 0;
+
+    /**
+     * The Server Key Public Exponent
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getServerKeyPublicExponent()
+     * @var String
+     * @access private
+     */
+    var $server_key_public_exponent;
+
+    /**
+     * The Server Key Public Modulus
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getServerKeyPublicModulus()
+     * @var String
+     * @access private
+     */
+    var $server_key_public_modulus;
+
+    /**
+     * The Host Key Public Exponent
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getHostKeyPublicExponent()
+     * @var String
+     * @access private
+     */
+    var $host_key_public_exponent;
+
+    /**
+     * The Host Key Public Modulus
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getHostKeyPublicModulus()
+     * @var String
+     * @access private
+     */
+    var $host_key_public_modulus;
+
+    /**
+     * Supported Ciphers
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getSupportedCiphers()
+     * @var Array
+     * @access private
+     */
+    var $supported_ciphers = array(
+        NET_SSH1_CIPHER_NONE       => 'No encryption',
+        NET_SSH1_CIPHER_IDEA       => 'IDEA in CFB mode',
+        NET_SSH1_CIPHER_DES        => 'DES in CBC mode',
+        NET_SSH1_CIPHER_3DES       => 'Triple-DES in CBC mode',
+        NET_SSH1_CIPHER_BROKEN_TSS => 'TRI\'s Simple Stream encryption CBC',
+        NET_SSH1_CIPHER_RC4        => 'RC4',
+        NET_SSH1_CIPHER_BLOWFISH   => 'Blowfish'
+    );
+
+    /**
+     * Supported Authentications
+     *
+     * Logged for debug purposes
+     *
+     * @see Net_SSH1::getSupportedAuthentications()
+     * @var Array
+     * @access private
+     */
+    var $supported_authentications = array(
+        NET_SSH1_AUTH_RHOSTS     => '.rhosts or /etc/hosts.equiv',
+        NET_SSH1_AUTH_RSA        => 'pure RSA authentication',
+        NET_SSH1_AUTH_PASSWORD   => 'password authentication',
+        NET_SSH1_AUTH_RHOSTS_RSA => '.rhosts with RSA host authentication'
+    );
+
+    /**
+     * Server Identification
+     *
+     * @see Net_SSH1::getServerIdentification()
+     * @var String
+     * @access private
+     */
+    var $server_identification = '';
+
+    /**
+     * Default Constructor.
+     *
+     * Connects to an SSHv1 server
+     *
+     * @param String $host
+     * @param optional Integer $port
+     * @param optional Integer $timeout
+     * @param optional Integer $cipher
+     * @return Net_SSH1
+     * @access public
+     */
+    function Net_SSH1($host, $port = 22, $timeout = 10, $cipher = NET_SSH1_CIPHER_3DES)
+    {
+        $this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
+        if (!$this->fsock) {
+            user_error(rtrim("Cannot connect to $host. Error $errno. $errstr"), E_USER_NOTICE);
+            return;
+        }
+
+        $this->server_identification = $init_line = fgets($this->fsock, 255);
+        if (!preg_match('#SSH-([0-9\.]+)-(.+)#', $init_line, $parts)) {
+            user_error('Can only connect to SSH servers', E_USER_NOTICE);
+            return;
+        }
+        if ($parts[1][0] != 1) {
+            user_error("Cannot connect to SSH $parts[1] servers", E_USER_NOTICE);
+            return;
+        }
+
+        fputs($this->fsock, $this->identifier."\r\n");
+
+        $response = $this->_get_binary_packet();
+        if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_PUBLIC_KEY) {
+            user_error('Expected SSH_SMSG_PUBLIC_KEY', E_USER_NOTICE);
+            return;
+        }
+
+        $anti_spoofing_cookie = $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 8);
+
+        $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
+
+        $temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
+        $server_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
+        $this->server_key_public_exponent = $server_key_public_exponent;
+
+        $temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
+        $server_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
+        $this->server_key_public_modulus = $server_key_public_modulus;
+
+        $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
+
+        $temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
+        $host_key_public_exponent = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
+        $this->host_key_public_exponent = $host_key_public_exponent;
+
+        $temp = unpack('nlen', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 2));
+        $host_key_public_modulus = new Math_BigInteger($this->_string_shift($response[NET_SSH1_RESPONSE_DATA], ceil($temp['len'] / 8)), 256);
+        $this->host_key_public_modulus = $host_key_public_modulus;
+
+        $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4);
+
+        // get a list of the supported ciphers
+        extract(unpack('Nsupported_ciphers_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
+        foreach ($this->supported_ciphers as $mask=>$name) {
+            if (($supported_ciphers_mask & (1 << $mask)) == 0) {
+                unset($this->supported_ciphers[$mask]);
+            }
+        }
+
+        // get a list of the supported authentications
+        extract(unpack('Nsupported_authentications_mask', $this->_string_shift($response[NET_SSH1_RESPONSE_DATA], 4)));
+        foreach ($this->supported_authentications as $mask=>$name) {
+            if (($supported_authentications_mask & (1 << $mask)) == 0) {
+                unset($this->supported_authentications[$mask]);
+            }
+        }
+
+        $session_id = pack('H*', md5($host_key_public_modulus->toBytes() . $server_key_public_modulus->toBytes() . $anti_spoofing_cookie));
+
+        $session_key = '';
+        for ($i = 0; $i < 32; $i++) {
+            $session_key.= chr(crypt_random(0, 255));
+        }
+        $double_encrypted_session_key = $session_key ^ str_pad($session_id, 32, chr(0));
+
+        if ($server_key_public_modulus->compare($host_key_public_modulus) < 0) {
+            $double_encrypted_session_key = $this->_rsa_crypt(
+                $double_encrypted_session_key,
+                array(
+                    $server_key_public_exponent,
+                    $server_key_public_modulus
+                )
+            );
+            $double_encrypted_session_key = $this->_rsa_crypt(
+                $double_encrypted_session_key,
+                array(
+                    $host_key_public_exponent,
+                    $host_key_public_modulus
+                )
+            );
+        } else {
+            $double_encrypted_session_key = $this->_rsa_crypt(
+                $double_encrypted_session_key,
+                array(
+                    $host_key_public_exponent,
+                    $host_key_public_modulus
+                )
+            );
+            $double_encrypted_session_key = $this->_rsa_crypt(
+                $double_encrypted_session_key,
+                array(
+                    $server_key_public_exponent,
+                    $server_key_public_modulus
+                )
+            );
+        }
+
+        $cipher = isset($this->supported_ciphers[$cipher]) ? $cipher : NET_SSH1_CIPHER_3DES;
+        $data = pack('C2a*na*N', NET_SSH1_CMSG_SESSION_KEY, $cipher, $anti_spoofing_cookie, 8 * strlen($double_encrypted_session_key), $double_encrypted_session_key, 0);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_SESSION_KEY', E_USER_NOTICE);
+            return;
+        }
+
+        switch ($cipher) {
+            //case NET_SSH1_CIPHER_NONE:
+            //    $this->crypto = new Crypt_Null();
+            //    break;
+            case NET_SSH1_CIPHER_DES:
+                $this->crypto = new Crypt_DES();
+                $this->crypto->disablePadding();
+                $this->crypto->enableContinuousBuffer();
+                $this->crypto->setKey(substr($session_key, 0,  8));
+                break;
+            case NET_SSH1_CIPHER_3DES:
+                $this->crypto = new Crypt_TripleDES(CRYPT_DES_MODE_3CBC);
+                $this->crypto->disablePadding();
+                $this->crypto->enableContinuousBuffer();
+                $this->crypto->setKey(substr($session_key, 0, 24));
+                break;
+            //case NET_SSH1_CIPHER_RC4:
+            //    $this->crypto = new Crypt_RC4();
+            //    $this->crypto->enableContinuousBuffer();
+            //    $this->crypto->setKey(substr($session_key, 0,  16));
+            //    break;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
+            user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
+            return;
+        }
+
+        $this->bitmap = NET_SSH1_MASK_CONSTRUCTOR;
+    }
+
+    /**
+     * Login
+     *
+     * @param String $username
+     * @param optional String $password
+     * @return Boolean
+     * @access public
+     */
+    function login($username, $password = '')
+    {
+        if (!($this->bitmap & NET_SSH1_MASK_CONSTRUCTOR)) {
+            return false;
+        }
+
+        $data = pack('CNa*', NET_SSH1_CMSG_USER, strlen($username), $username);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_USER', E_USER_NOTICE);
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response[NET_SSH1_RESPONSE_TYPE] == NET_SSH1_SMSG_SUCCESS) {
+            $this->bitmap |= NET_SSH1_MASK_LOGIN;
+            return true;
+        } else if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_FAILURE) {
+            user_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE', E_USER_NOTICE);
+            return false;
+        }
+
+        $data = pack('CNa*', NET_SSH1_CMSG_AUTH_PASSWORD, strlen($password), $password);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_AUTH_PASSWORD', E_USER_NOTICE);
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response[NET_SSH1_RESPONSE_TYPE] == NET_SSH1_SMSG_SUCCESS) {
+            $this->bitmap |= NET_SSH1_MASK_LOGIN;
+            return true;
+        } else if ($response[NET_SSH1_RESPONSE_TYPE] == NET_SSH1_SMSG_FAILURE) {
+            return false;
+        } else {
+            user_error('Expected SSH_SMSG_SUCCESS or SSH_SMSG_FAILURE', E_USER_NOTICE);
+            return false;
+        }
+    }
+
+    /**
+     * Executes a command on a non-interactive shell, returns the output, and quits.
+     *
+     * An SSH1 server will close the connection after a command has been executed on a non-interactive shell.  SSH2
+     * servers don't, however, this isn't an SSH2 client.  The way this works, on the server, is by initiating a
+     * shell with the -s option, as discussed in the following links:
+     *
+     * {@link http://www.faqs.org/docs/bashman/bashref_65.html http://www.faqs.org/docs/bashman/bashref_65.html}
+     * {@link http://www.faqs.org/docs/bashman/bashref_62.html http://www.faqs.org/docs/bashman/bashref_62.html}
+     *
+     * To execute further commands, a new Net_SSH1 object will need to be created.
+     *
+     * Returns false on failure and the output, otherwise.
+     *
+     * @see Net_SSH1::interactiveRead()
+     * @see Net_SSH1::interactiveWrite()
+     * @param String $cmd
+     * @return mixed
+     * @access public
+     */
+    function exec($cmd)
+    {
+        if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
+            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            return false;
+        }
+
+        // connect using the sample parameters in protocol-1.5.txt.
+        // according to wikipedia.org's entry on text terminals, "the fundamental type of application running on a text
+        // terminal is a command line interpreter or shell".  thus, opening a terminal session to run the shell.
+        $data = pack('CNa*N4C', NET_SSH1_CMSG_REQUEST_PTY, strlen('vt100'), 'vt100', 24, 80, 0, 0, NET_SSH1_TTY_OP_END);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_REQUEST_PTY', E_USER_NOTICE);
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
+            user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
+            return false;
+        }
+
+        $data = pack('CNa*', NET_SSH1_CMSG_EXEC_CMD, strlen($cmd), $cmd);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_EXEC_CMD', E_USER_NOTICE);
+            return false;
+        }
+
+        $output = '';
+        $response = $this->_get_binary_packet();
+
+        do {
+            $output.= substr($response[NET_SSH1_RESPONSE_DATA], 4);
+            $response = $this->_get_binary_packet();
+        } while ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_EXITSTATUS);
+
+        $data = pack('C', NET_SSH1_CMSG_EXIT_CONFIRMATION);
+
+        // i don't think it's really all that important if this packet gets sent or not.
+        $this->_send_binary_packet($data);
+
+        fclose($this->fsock);
+
+        // reset the execution bitmap - a new Net_SSH1 object needs to be created.
+        $this->bitmap = 0;
+
+        return $output;
+    }
+
+    /**
+     * Creates an interactive shell
+     *
+     * @see Net_SSH1::interactiveRead()
+     * @see Net_SSH1::interactiveWrite()
+     * @return Boolean
+     * @access private
+     */
+    function _initShell()
+    {
+        $data = pack('CNa*N4C', NET_SSH1_CMSG_REQUEST_PTY, strlen('vt100'), 'vt100', 24, 80, 0, 0, NET_SSH1_TTY_OP_END);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_REQUEST_PTY', E_USER_NOTICE);
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response[NET_SSH1_RESPONSE_TYPE] != NET_SSH1_SMSG_SUCCESS) {
+            user_error('Expected SSH_SMSG_SUCCESS', E_USER_NOTICE);
+            return false;
+        }
+
+        $data = pack('C', NET_SSH1_CMSG_EXEC_SHELL);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_EXEC_SHELL', E_USER_NOTICE);
+            return false;
+        }
+
+        $this->bitmap |= NET_SSH1_MASK_SHELL;
+
+        //stream_set_blocking($this->fsock, 0);
+
+        return true;
+    }
+
+    /**
+     * Inputs a command into an interactive shell.
+     *
+     * @see Net_SSH1::interactiveRead()
+     * @param String $cmd
+     * @return Boolean
+     * @access public
+     */
+    function interactiveWrite($cmd)
+    {
+        if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
+            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            return false;
+        }
+
+        if (!($this->bitmap & NET_SSH1_MASK_SHELL) && !$this->_initShell()) {
+            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            return false;
+        }
+
+        $data = pack('CNa*', NET_SSH1_CMSG_STDIN_DATA, strlen($cmd), $cmd);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Error sending SSH_CMSG_STDIN', E_USER_NOTICE);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Reads the output of an interactive shell.
+     *
+     * Requires PHP 4.3.0 or later due to the use of the stream_select() function.  If you see stuff like
+     * "[00m", you're seeing ANSI escape codes.  According to
+     * {@link http://support.microsoft.com/kb/101875 How to Enable ANSI.SYS in a Command Window}, "Windows NT
+     * does not support ANSI escape sequences in Win32 Console applications", so if you're a Windows user,
+     * there's not going to be much recourse.
+     *
+     * @see Net_SSH1::interactiveRead()
+     * @return String
+     * @access public
+     */
+    function interactiveRead()
+    {
+        if (!($this->bitmap & NET_SSH1_MASK_LOGIN)) {
+            user_error('Operation disallowed prior to login()', E_USER_NOTICE);
+            return false;
+        }
+
+        if (!($this->bitmap & NET_SSH1_MASK_SHELL) && !$this->_initShell()) {
+            user_error('Unable to initiate an interactive shell session', E_USER_NOTICE);
+            return false;
+        }
+
+        $read = array($this->fsock);
+        $write = $except = null;
+        if (stream_select($read, $write, $except, 0)) {
+            $response = $this->_get_binary_packet();
+            return substr($response[NET_SSH1_RESPONSE_DATA], 4);
+        } else {
+            return '';
+        }
+    }
+
+    /**
+     * Disconnect
+     *
+     * @access public
+     */
+    function disconnect()
+    {
+        $this->_disconnect();
+    }
+
+    /**
+     * Destructor.
+     *
+     * Will be called, automatically, if you're supporting just PHP5.  If you're supporting PHP4, you'll need to call
+     * disconnect().
+     *
+     * @access public
+     */
+    function __destruct()
+    {
+        $this->_disconnect();
+    }
+
+    /**
+     * Disconnect
+     *
+     * @param String $msg
+     * @access private
+     */
+    function _disconnect($msg = 'Client Quit')
+    {
+        if ($this->bitmap) {
+            $data = pack('CNa*', NET_SSH1_MSG_DISCONNECT, strlen($msg), $msg);
+            $this->_send_binary_packet($data);
+            fclose($this->fsock);
+            $this->bitmap = 0;
+        }
+    }
+
+    /**
+     * Gets Binary Packets
+     *
+     * See 'The Binary Packet Protocol' of protocol-1.5.txt for more info.
+     *
+     * Also, this function could be improved upon by adding detection for the following exploit:
+     * http://www.securiteam.com/securitynews/5LP042K3FY.html
+     *
+     * @see Net_SSH1::_send_binary_packet()
+     * @return Array
+     * @access private
+     */
+    function _get_binary_packet()
+    {
+        if (feof($this->fsock)) {
+            //user_error('connection closed prematurely', E_USER_NOTICE);
+            return false;
+        }
+
+        $temp = unpack('Nlength', fread($this->fsock, 4));
+
+        $padding_length = 8 - ($temp['length'] & 7);
+        $length = $temp['length'] + $padding_length;
+
+        $raw = fread($this->fsock, $length);
+
+        if ($this->crypto !== false) {
+            $raw = $this->crypto->decrypt($raw);
+        }
+
+        $padding = substr($raw, 0, $padding_length);
+        $type = $raw[$padding_length];
+        $data = substr($raw, $padding_length + 1, -4);
+
+        $temp = unpack('Ncrc', substr($raw, -4));
+
+        //if ( $temp['crc'] != $this->_crc($padding . $type . $data) ) {
+        //    user_error('Bad CRC in packet from server', E_USER_NOTICE);
+        //    return false;
+        //}
+
+        return array(
+            NET_SSH1_RESPONSE_TYPE => ord($type),
+            NET_SSH1_RESPONSE_DATA => $data
+        );
+    }
+
+    /**
+     * Sends Binary Packets
+     *
+     * Returns true on success, false on failure.
+     *
+     * @see Net_SSH1::_get_binary_packet()
+     * @param String $data
+     * @return Boolean
+     * @access private
+     */
+    function _send_binary_packet($data) {
+        if (feof($this->fsock)) {
+            //user_error('connection closed prematurely', E_USER_NOTICE);
+            return false;
+        }
+
+        $length = strlen($data) + 4;
+
+        $padding_length = 8 - ($length & 7);
+        $padding = '';
+        for ($i = 0; $i < $padding_length; $i++) {
+            $padding.= chr(crypt_random(0, 255));
+        }
+
+        $data = $padding . $data;
+        $data.= pack('N', $this->_crc($data));
+
+        if ($this->crypto !== false) {
+            $data = $this->crypto->encrypt($data);
+        }
+
+        $packet = pack('Na*', $length, $data);
+
+        return strlen($packet) == fputs($this->fsock, $packet);
+    }
+
+    /**
+     * Cyclic Redundancy Check (CRC)
+     *
+     * PHP's crc32 function is implemented slightly differently than the one that SSH v1 uses, so
+     * we've reimplemented it. A more detailed discussion of the differences can be found after
+     * $crc_lookup_table's initialization.
+     *
+     * @see Net_SSH1::_get_binary_packet()
+     * @see Net_SSH1::_send_binary_packet()
+     * @param String $data
+     * @return Integer
+     * @access private
+     */
+    function _crc($data)
+    {
+        static $crc_lookup_table = array(
+            0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
+            0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
+            0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
+            0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
+            0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
+            0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+            0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
+            0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
+            0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
+            0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
+            0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
+            0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+            0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
+            0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+            0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
+            0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
+            0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
+            0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+            0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
+            0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
+            0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
+            0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
+            0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
+            0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+            0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
+            0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
+            0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
+            0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
+            0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
+            0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+            0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
+            0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
+            0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
+            0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
+            0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
+            0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+            0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
+            0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
+            0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+            0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
+            0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
+            0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+            0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
+            0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
+            0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
+            0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+            0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
+            0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+            0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
+            0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
+            0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
+            0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
+            0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
+            0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+            0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
+            0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
+            0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
+            0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
+            0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
+            0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+            0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
+            0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+            0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
+            0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
+        );
+
+        // For this function to yield the same output as PHP's crc32 function, $crc would have to be
+        // set to 0xFFFFFFFF, initially - not 0x00000000 as it currently is.
+        $crc = 0x00000000;
+        $length = strlen($data);
+
+        for ($i=0;$i<$length;$i++) {
+            // We AND $crc >> 8 with 0x00FFFFFF because we want the eight newly added bits to all
+            // be zero.  PHP, unfortunately, doesn't always do this.  0x80000000 >> 8, as an example,
+            // yields 0xFF800000 - not 0x00800000.  The following link elaborates:
+            // http://www.php.net/manual/en/language.operators.bitwise.php#57281
+            $crc = (($crc >> 8) & 0x00FFFFFF) ^ $crc_lookup_table[($crc & 0xFF) ^ ord($data[$i])];
+        }
+
+        // In addition to having to set $crc to 0xFFFFFFFF, initially, the return value must be XOR'd with
+        // 0xFFFFFFFF for this function to return the same thing that PHP's crc32 function would.
+        return $crc;
+    }
+
+    /**
+     * String Shift
+     *
+     * Inspired by array_shift
+     *
+     * @param String $string
+     * @param optional Integer $index
+     * @return String
+     * @access private
+     */
+    function _string_shift(&$string, $index = 1)
+    {
+        $substr = substr($string, 0, $index);
+        $string = substr($string, $index);
+        return $substr;
+    }
+
+    /**
+     * RSA Encrypt
+     *
+     * Returns mod(pow($m, $e), $n), where $n should be the product of two (large) primes $p and $q and where $e
+     * should be a number with the property that gcd($e, ($p - 1) * ($q - 1)) == 1.  Could just make anything that
+     * calls this call modexp, instead, but I think this makes things clearer, maybe...
+     *
+     * @see Net_SSH1::Net_SSH1()
+     * @param Math_BigInteger $m
+     * @param Array $key
+     * @return Math_BigInteger
+     * @access private
+     */
+    function _rsa_crypt($m, $key)
+    {
+        /*
+        if (!class_exists('Crypt_RSA')) {
+            require_once('Crypt/RSA.php');
+        }
+
+        $rsa = new Crypt_RSA();
+        $rsa->loadKey($key, CRYPT_RSA_PUBLIC_FORMAT_RAW);
+        $rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
+        return $rsa->encrypt($m);
+        */
+
+        // To quote from protocol-1.5.txt:
+        // The most significant byte (which is only partial as the value must be
+        // less than the public modulus, which is never a power of two) is zero.
+        //
+        // The next byte contains the value 2 (which stands for public-key
+        // encrypted data in the PKCS standard [PKCS#1]).  Then, there are non-
+        // zero random bytes to fill any unused space, a zero byte, and the data
+        // to be encrypted in the least significant bytes, the last byte of the
+        // data in the least significant byte.
+
+        // Presumably the part of PKCS#1 they're refering to is "Section 7.2.1 Encryption Operation",
+        // under "7.2 RSAES-PKCS1-v1.5" and "7 Encryption schemes" of the following URL:
+        // ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf
+        $temp = chr(0) . chr(2);
+        $modulus = $key[1]->toBytes();
+        $length = strlen($modulus) - strlen($m) - 3;
+        for ($i = 0; $i < $length; $i++) {
+            $temp.= chr(crypt_random(1, 255));
+        }
+        $temp.= chr(0) . $m;
+
+        $m = new Math_BigInteger($temp, 256);
+        $m = $m->modPow($key[0], $key[1]);
+
+        return $m->toBytes();
+    }
+
+    /**
+     * Return the server key public exponent
+     *
+     * Returns, by default, the base-10 representation.  If $raw_output is set to true, returns, instead,
+     * the raw bytes.  This behavior is similar to PHP's md5() function.
+     *
+     * @param optional Boolean $raw_output
+     * @return String
+     * @access public
+     */
+    function getServerKeyPublicExponent($raw_output = false)
+    {
+        return $raw_output ? $this->server_key_public_exponent->toBytes() : $this->server_key_public_exponent->toString();
+    }
+
+    /**
+     * Return the server key public modulus
+     *
+     * Returns, by default, the base-10 representation.  If $raw_output is set to true, returns, instead,
+     * the raw bytes.  This behavior is similar to PHP's md5() function.
+     *
+     * @param optional Boolean $raw_output
+     * @return String
+     * @access public
+     */
+    function getServerKeyPublicModulus($raw_output = false)
+    {
+        return $raw_output ? $this->server_key_public_modulus->toBytes() : $this->server_key_public_modulus->toString();
+    }
+
+    /**
+     * Return the host key public exponent
+     *
+     * Returns, by default, the base-10 representation.  If $raw_output is set to true, returns, instead,
+     * the raw bytes.  This behavior is similar to PHP's md5() function.
+     *
+     * @param optional Boolean $raw_output
+     * @return String
+     * @access public
+     */
+    function getHostKeyPublicExponent($raw_output = false)
+    {
+        return $raw_output ? $this->host_key_public_exponent->toBytes() : $this->host_key_public_exponent->toString();
+    }
+
+    /**
+     * Return the host key public modulus
+     *
+     * Returns, by default, the base-10 representation.  If $raw_output is set to true, returns, instead,
+     * the raw bytes.  This behavior is similar to PHP's md5() function.
+     *
+     * @param optional Boolean $raw_output
+     * @return String
+     * @access public
+     */
+    function getHostKeyPublicModulus($raw_output = false)
+    {
+        return $raw_output ? $this->host_key_public_modulus->toBytes() : $this->host_key_public_modulus->toString();
+    }
+
+    /**
+     * Return a list of ciphers supported by SSH1 server.
+     *
+     * Just because a cipher is supported by an SSH1 server doesn't mean it's supported by this library. If $raw_output
+     * is set to true, returns, instead, an array of constants.  ie. instead of array('Triple-DES in CBC mode'), you'll
+     * get array(NET_SSH1_CIPHER_3DES).
+     *
+     * @param optional Boolean $raw_output
+     * @return Array
+     * @access public
+     */
+    function getSupportedCiphers($raw_output = false)
+    {
+        return $raw_output ? array_keys($this->supported_ciphers) : array_values($this->supported_ciphers);
+    }
+
+    /**
+     * Return a list of authentications supported by SSH1 server.
+     *
+     * Just because a cipher is supported by an SSH1 server doesn't mean it's supported by this library. If $raw_output
+     * is set to true, returns, instead, an array of constants.  ie. instead of array('password authentication'), you'll
+     * get array(NET_SSH1_AUTH_PASSWORD).
+     *
+     * @param optional Boolean $raw_output
+     * @return Array
+     * @access public
+     */
+    function getSupportedAuthentications($raw_output = false)
+    {
+        return $raw_output ? array_keys($this->supported_authentications) : array_values($this->supported_authentications);
+    }
+
+    /**
+     * Return the server identification.
+     *
+     * @return String
+     * @access public
+     */
+    function getServerIdentification()
+    {
+        return rtrim($this->server_identification);
+    }
+}
+?>
+\ No newline at end of file
diff --git a/phpsec/Net/SSH2.php b/phpsec/Net/SSH2.php
new file mode 100644
index 000000000..aa9f6dbe5
--- /dev/null
+++ b/phpsec/Net/SSH2.php
@@ -0,0 +1,2302 @@
+<?php
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Pure-PHP implementation of SSHv2.
+ *
+ * PHP versions 4 and 5
+ *
+ * Here are some examples of how to use this library:
+ * <code>
+ * <?php
+ *    include('Net/SSH2.php');
+ *
+ *    $ssh = new Net_SSH2('www.domain.tld');
+ *    if (!$ssh->login('username', 'password')) {
+ *        exit('Login Failed');
+ *    }
+ *
+ *    echo $ssh->exec('pwd');
+ *    echo $ssh->exec('ls -la');
+ * ?>
+ * </code>
+ *
+ * <code>
+ * <?php
+ *    include('Crypt/RSA.php');
+ *    include('Net/SSH2.php');
+ *
+ *    $key = new Crypt_RSA();
+ *    //$key->setPassword('whatever');
+ *    $key->loadKey(file_get_contents('privatekey'));
+ *
+ *    $ssh = new Net_SSH2('www.domain.tld');
+ *    if (!$ssh->login('username', $key)) {
+ *        exit('Login Failed');
+ *    }
+ *
+ *    echo $ssh->exec('pwd');
+ *    echo $ssh->exec('ls -la');
+ * ?>
+ * </code>
+ *
+ * LICENSE: This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA  02111-1307  USA
+ *
+ * @category   Net
+ * @package    Net_SSH2
+ * @author     Jim Wigginton <terrafrost@php.net>
+ * @copyright  MMVII Jim Wigginton
+ * @license    http://www.gnu.org/licenses/lgpl.txt
+ * @version    $Id: SSH2.php,v 1.46 2010/04/27 21:29:36 terrafrost Exp $
+ * @link       http://phpseclib.sourceforge.net
+ */
+
+/**
+ * Include Math_BigInteger
+ *
+ * Used to do Diffie-Hellman key exchange and DSA/RSA signature verification.
+ */
+require_once('Math/BigInteger.php');
+
+/**
+ * Include Crypt_Random
+ */
+require_once('Crypt/Random.php');
+
+/**
+ * Include Crypt_Hash
+ */
+require_once('Crypt/Hash.php');
+
+/**
+ * Include Crypt_TripleDES
+ */
+require_once('Crypt/TripleDES.php');
+
+/**
+ * Include Crypt_RC4
+ */
+require_once('Crypt/RC4.php');
+
+/**
+ * Include Crypt_AES
+ */
+require_once('Crypt/AES.php');
+
+/**#@+
+ * Execution Bitmap Masks
+ *
+ * @see Net_SSH2::bitmap
+ * @access private
+ */
+define('NET_SSH2_MASK_CONSTRUCTOR', 0x00000001);
+define('NET_SSH2_MASK_LOGIN',       0x00000002);
+/**#@-*/
+
+/**#@+
+ * Channel constants
+ *
+ * RFC4254 refers not to client and server channels but rather to sender and recipient channels.  we don't refer
+ * to them in that way because RFC4254 toggles the meaning. the client sends a SSH_MSG_CHANNEL_OPEN message with
+ * a sender channel and the server sends a SSH_MSG_CHANNEL_OPEN_CONFIRMATION in response, with a sender and a
+ * recepient channel.  at first glance, you might conclude that SSH_MSG_CHANNEL_OPEN_CONFIRMATION's sender channel
+ * would be the same thing as SSH_MSG_CHANNEL_OPEN's sender channel, but it's not, per this snipet:
+ *     The 'recipient channel' is the channel number given in the original
+ *     open request, and 'sender channel' is the channel number allocated by
+ *     the other side.
+ *
+ * @see Net_SSH2::_send_channel_packet()
+ * @see Net_SSH2::_get_channel_packet()
+ * @access private
+ */
+define('NET_SSH2_CHANNEL_EXEC', 0); // PuTTy uses 0x100
+/**#@-*/
+
+/**#@+
+ * @access public
+ * @see Net_SSH2::getLog()
+ */
+/**
+ * Returns the message numbers
+ */
+define('NET_SSH2_LOG_SIMPLE',  1);
+/**
+ * Returns the message content
+ */
+define('NET_SSH2_LOG_COMPLEX', 2);
+/**#@-*/
+
+/**
+ * Pure-PHP implementation of SSHv2.
+ *
+ * @author  Jim Wigginton <terrafrost@php.net>
+ * @version 0.1.0
+ * @access  public
+ * @package Net_SSH2
+ */
+class Net_SSH2 {
+    /**
+     * The SSH identifier
+     *
+     * @var String
+     * @access private
+     */
+    var $identifier = 'SSH-2.0-phpseclib_0.2';
+
+    /**
+     * The Socket Object
+     *
+     * @var Object
+     * @access private
+     */
+    var $fsock;
+
+    /**
+     * Execution Bitmap
+     *
+     * The bits that are set reprsent functions that have been called already.  This is used to determine
+     * if a requisite function has been successfully executed.  If not, an error should be thrown.
+     *
+     * @var Integer
+     * @access private
+     */
+    var $bitmap = 0;
+
+    /**
+     * Error information
+     *
+     * @see Net_SSH2::getErrors()
+     * @see Net_SSH2::getLastError()
+     * @var String
+     * @access private
+     */
+    var $errors = array();
+
+    /**
+     * Server Identifier
+     *
+     * @see Net_SSH2::getServerIdentification()
+     * @var String
+     * @access private
+     */
+    var $server_identifier = '';
+
+    /**
+     * Key Exchange Algorithms
+     *
+     * @see Net_SSH2::getKexAlgorithims()
+     * @var Array
+     * @access private
+     */
+    var $kex_algorithms;
+
+    /**
+     * Server Host Key Algorithms
+     *
+     * @see Net_SSH2::getServerHostKeyAlgorithms()
+     * @var Array
+     * @access private
+     */
+    var $server_host_key_algorithms;
+
+    /**
+     * Encryption Algorithms: Client to Server
+     *
+     * @see Net_SSH2::getEncryptionAlgorithmsClient2Server()
+     * @var Array
+     * @access private
+     */
+    var $encryption_algorithms_client_to_server;
+
+    /**
+     * Encryption Algorithms: Server to Client
+     *
+     * @see Net_SSH2::getEncryptionAlgorithmsServer2Client()
+     * @var Array
+     * @access private
+     */
+    var $encryption_algorithms_server_to_client;
+
+    /**
+     * MAC Algorithms: Client to Server
+     *
+     * @see Net_SSH2::getMACAlgorithmsClient2Server()
+     * @var Array
+     * @access private
+     */
+    var $mac_algorithms_client_to_server;
+
+    /**
+     * MAC Algorithms: Server to Client
+     *
+     * @see Net_SSH2::getMACAlgorithmsServer2Client()
+     * @var Array
+     * @access private
+     */
+    var $mac_algorithms_server_to_client;
+
+    /**
+     * Compression Algorithms: Client to Server
+     *
+     * @see Net_SSH2::getCompressionAlgorithmsClient2Server()
+     * @var Array
+     * @access private
+     */
+    var $compression_algorithms_client_to_server;
+
+    /**
+     * Compression Algorithms: Server to Client
+     *
+     * @see Net_SSH2::getCompressionAlgorithmsServer2Client()
+     * @var Array
+     * @access private
+     */
+    var $compression_algorithms_server_to_client;
+
+    /**
+     * Languages: Server to Client
+     *
+     * @see Net_SSH2::getLanguagesServer2Client()
+     * @var Array
+     * @access private
+     */
+    var $languages_server_to_client;
+
+    /**
+     * Languages: Client to Server
+     *
+     * @see Net_SSH2::getLanguagesClient2Server()
+     * @var Array
+     * @access private
+     */
+    var $languages_client_to_server;
+
+    /**
+     * Block Size for Server to Client Encryption
+     *
+     * "Note that the length of the concatenation of 'packet_length',
+     *  'padding_length', 'payload', and 'random padding' MUST be a multiple
+     *  of the cipher block size or 8, whichever is larger.  This constraint
+     *  MUST be enforced, even when using stream ciphers."
+     *
+     *  -- http://tools.ietf.org/html/rfc4253#section-6
+     *
+     * @see Net_SSH2::Net_SSH2()
+     * @see Net_SSH2::_send_binary_packet()
+     * @var Integer
+     * @access private
+     */
+    var $encrypt_block_size = 8;
+
+    /**
+     * Block Size for Client to Server Encryption
+     *
+     * @see Net_SSH2::Net_SSH2()
+     * @see Net_SSH2::_get_binary_packet()
+     * @var Integer
+     * @access private
+     */
+    var $decrypt_block_size = 8;
+
+    /**
+     * Server to Client Encryption Object
+     *
+     * @see Net_SSH2::_get_binary_packet()
+     * @var Object
+     * @access private
+     */
+    var $decrypt = false;
+
+    /**
+     * Client to Server Encryption Object
+     *
+     * @see Net_SSH2::_send_binary_packet()
+     * @var Object
+     * @access private
+     */
+    var $encrypt = false;
+
+    /**
+     * Client to Server HMAC Object
+     *
+     * @see Net_SSH2::_send_binary_packet()
+     * @var Object
+     * @access private
+     */
+    var $hmac_create = false;
+
+    /**
+     * Server to Client HMAC Object
+     *
+     * @see Net_SSH2::_get_binary_packet()
+     * @var Object
+     * @access private
+     */
+    var $hmac_check = false;
+
+    /**
+     * Size of server to client HMAC
+     *
+     * We need to know how big the HMAC will be for the server to client direction so that we know how many bytes to read.
+     * For the client to server side, the HMAC object will make the HMAC as long as it needs to be.  All we need to do is
+     * append it.
+     *
+     * @see Net_SSH2::_get_binary_packet()
+     * @var Integer
+     * @access private
+     */
+    var $hmac_size = false;
+
+    /**
+     * Server Public Host Key
+     *
+     * @see Net_SSH2::getServerPublicHostKey()
+     * @var String
+     * @access private
+     */
+    var $server_public_host_key;
+
+    /**
+     * Session identifer
+     *
+     * "The exchange hash H from the first key exchange is additionally
+     *  used as the session identifier, which is a unique identifier for
+     *  this connection."
+     *
+     *  -- http://tools.ietf.org/html/rfc4253#section-7.2
+     *
+     * @see Net_SSH2::_key_exchange()
+     * @var String
+     * @access private
+     */
+    var $session_id = false;
+
+    /**
+     * Message Numbers
+     *
+     * @see Net_SSH2::Net_SSH2()
+     * @var Array
+     * @access private
+     */
+    var $message_numbers = array();
+
+    /**
+     * Disconnection Message 'reason codes' defined in RFC4253
+     *
+     * @see Net_SSH2::Net_SSH2()
+     * @var Array
+     * @access private
+     */
+    var $disconnect_reasons = array();
+
+    /**
+     * SSH_MSG_CHANNEL_OPEN_FAILURE 'reason codes', defined in RFC4254
+     *
+     * @see Net_SSH2::Net_SSH2()
+     * @var Array
+     * @access private
+     */
+    var $channel_open_failure_reasons = array();
+
+    /**
+     * Terminal Modes
+     *
+     * @link http://tools.ietf.org/html/rfc4254#section-8
+     * @see Net_SSH2::Net_SSH2()
+     * @var Array
+     * @access private
+     */
+    var $terminal_modes = array();
+
+    /**
+     * SSH_MSG_CHANNEL_EXTENDED_DATA's data_type_codes
+     *
+     * @link http://tools.ietf.org/html/rfc4254#section-5.2
+     * @see Net_SSH2::Net_SSH2()
+     * @var Array
+     * @access private
+     */
+    var $channel_extended_data_type_codes = array();
+
+    /**
+     * Send Sequence Number
+     *
+     * See 'Section 6.4.  Data Integrity' of rfc4253 for more info.
+     *
+     * @see Net_SSH2::_send_binary_packet()
+     * @var Integer
+     * @access private
+     */
+    var $send_seq_no = 0;
+
+    /**
+     * Get Sequence Number
+     *
+     * See 'Section 6.4.  Data Integrity' of rfc4253 for more info.
+     *
+     * @see Net_SSH2::_get_binary_packet()
+     * @var Integer
+     * @access private
+     */
+    var $get_seq_no = 0;
+
+    /**
+     * Server Channels
+     *
+     * Maps client channels to server channels
+     *
+     * @see Net_SSH2::_get_channel_packet()
+     * @see Net_SSH2::exec()
+     * @var Array
+     * @access private
+     */
+    var $server_channels = array();
+
+    /**
+     * Channel Buffers
+     *
+     * If a client requests a packet from one channel but receives two packets from another those packets should
+     * be placed in a buffer
+     *
+     * @see Net_SSH2::_get_channel_packet()
+     * @see Net_SSH2::exec()
+     * @var Array
+     * @access private
+     */
+    var $channel_buffers = array();
+
+    /**
+     * Channel Status
+     *
+     * Contains the type of the last sent message
+     *
+     * @see Net_SSH2::_get_channel_packet()
+     * @var Array
+     * @access private
+     */
+    var $channel_status = array();
+
+    /**
+     * Packet Size
+     *
+     * Maximum packet size indexed by channel
+     *
+     * @see Net_SSH2::_send_channel_packet()
+     * @var Array
+     * @access private
+     */
+    var $packet_size_client_to_server = array();
+
+    /**
+     * Message Number Log
+     *
+     * @see Net_SSH2::getLog()
+     * @var Array
+     * @access private
+     */
+    var $message_number_log = array();
+
+    /**
+     * Message Log
+     *
+     * @see Net_SSH2::getLog()
+     * @var Array
+     * @access private
+     */
+    var $message_log = array();
+
+    /**
+     * The Window Size
+     *
+     * Bytes the other party can send before it must wait for the window to be adjusted (0x7FFFFFFF = 4GB)
+     *
+     * @var Integer
+     * @see Net_SSH2::_send_channel_packet()
+     * @see Net_SSH2::exec()
+     * @access private
+     */
+    var $window_size = 0x7FFFFFFF;
+
+    /**
+     * Window size
+     *
+     * Window size indexed by channel
+     *
+     * @see Net_SSH2::_send_channel_packet()
+     * @var Array
+     * @access private
+     */
+    var $window_size_client_to_server = array();
+
+    /**
+     * Server signature
+     *
+     * Verified against $this->session_id
+     *
+     * @see Net_SSH2::getServerPublicHostKey()
+     * @var String
+     * @access private
+     */
+    var $signature = '';
+
+    /**
+     * Server signature format
+     *
+     * ssh-rsa or ssh-dss.
+     *
+     * @see Net_SSH2::getServerPublicHostKey()
+     * @var String
+     * @access private
+     */
+    var $signature_format = '';
+
+    /**
+     * Default Constructor.
+     *
+     * Connects to an SSHv2 server
+     *
+     * @param String $host
+     * @param optional Integer $port
+     * @param optional Integer $timeout
+     * @return Net_SSH2
+     * @access public
+     */
+    function Net_SSH2($host, $port = 22, $timeout = 10)
+    {
+        $this->message_numbers = array(
+            1 => 'NET_SSH2_MSG_DISCONNECT',
+            2 => 'NET_SSH2_MSG_IGNORE',
+            3 => 'NET_SSH2_MSG_UNIMPLEMENTED',
+            4 => 'NET_SSH2_MSG_DEBUG',
+            5 => 'NET_SSH2_MSG_SERVICE_REQUEST',
+            6 => 'NET_SSH2_MSG_SERVICE_ACCEPT',
+            20 => 'NET_SSH2_MSG_KEXINIT',
+            21 => 'NET_SSH2_MSG_NEWKEYS',
+            30 => 'NET_SSH2_MSG_KEXDH_INIT',
+            31 => 'NET_SSH2_MSG_KEXDH_REPLY',
+            50 => 'NET_SSH2_MSG_USERAUTH_REQUEST',
+            51 => 'NET_SSH2_MSG_USERAUTH_FAILURE',
+            52 => 'NET_SSH2_MSG_USERAUTH_SUCCESS',
+            53 => 'NET_SSH2_MSG_USERAUTH_BANNER',
+
+            80 => 'NET_SSH2_MSG_GLOBAL_REQUEST',
+            81 => 'NET_SSH2_MSG_REQUEST_SUCCESS',
+            82 => 'NET_SSH2_MSG_REQUEST_FAILURE',
+            90 => 'NET_SSH2_MSG_CHANNEL_OPEN',
+            91 => 'NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION',
+            92 => 'NET_SSH2_MSG_CHANNEL_OPEN_FAILURE',
+            93 => 'NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST',
+            94 => 'NET_SSH2_MSG_CHANNEL_DATA',
+            95 => 'NET_SSH2_MSG_CHANNEL_EXTENDED_DATA',
+            96 => 'NET_SSH2_MSG_CHANNEL_EOF',
+            97 => 'NET_SSH2_MSG_CHANNEL_CLOSE',
+            98 => 'NET_SSH2_MSG_CHANNEL_REQUEST',
+            99 => 'NET_SSH2_MSG_CHANNEL_SUCCESS',
+            100 => 'NET_SSH2_MSG_CHANNEL_FAILURE'
+        );
+        $this->disconnect_reasons = array(
+            1 => 'NET_SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT',
+            2 => 'NET_SSH2_DISCONNECT_PROTOCOL_ERROR',
+            3 => 'NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED',
+            4 => 'NET_SSH2_DISCONNECT_RESERVED',
+            5 => 'NET_SSH2_DISCONNECT_MAC_ERROR',
+            6 => 'NET_SSH2_DISCONNECT_COMPRESSION_ERROR',
+            7 => 'NET_SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE',
+            8 => 'NET_SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED',
+            9 => 'NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE',
+            10 => 'NET_SSH2_DISCONNECT_CONNECTION_LOST',
+            11 => 'NET_SSH2_DISCONNECT_BY_APPLICATION',
+            12 => 'NET_SSH2_DISCONNECT_TOO_MANY_CONNECTIONS',
+            13 => 'NET_SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER',
+            14 => 'NET_SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE',
+            15 => 'NET_SSH2_DISCONNECT_ILLEGAL_USER_NAME'
+        );
+        $this->channel_open_failure_reasons = array(
+            1 => 'NET_SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED'
+        );
+        $this->terminal_modes = array(
+            0 => 'NET_SSH2_TTY_OP_END'
+        );
+        $this->channel_extended_data_type_codes = array(
+            1 => 'NET_SSH2_EXTENDED_DATA_STDERR'
+        );
+
+        $this->_define_array(
+            $this->message_numbers,
+            $this->disconnect_reasons,
+            $this->channel_open_failure_reasons,
+            $this->terminal_modes,
+            $this->channel_extended_data_type_codes,
+            array(60 => 'NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ'),
+            array(60 => 'NET_SSH2_MSG_USERAUTH_PK_OK')
+        );
+
+        $this->fsock = @fsockopen($host, $port, $errno, $errstr, $timeout);
+        if (!$this->fsock) {
+            user_error(rtrim("Cannot connect to $host. Error $errno. $errstr"), E_USER_NOTICE);
+            return;
+        }
+
+        /* According to the SSH2 specs,
+
+          "The server MAY send other lines of data before sending the version
+           string.  Each line SHOULD be terminated by a Carriage Return and Line
+           Feed.  Such lines MUST NOT begin with "SSH-", and SHOULD be encoded
+           in ISO-10646 UTF-8 [RFC3629] (language is not specified).  Clients
+           MUST be able to process such lines." */
+        $temp = '';
+        $extra = '';
+        while (!feof($this->fsock) && !preg_match('#^SSH-(\d\.\d+)#', $temp, $matches)) {
+            if (substr($temp, -2) == "\r\n") {
+                $extra.= $temp;
+                $temp = '';
+            }
+            $temp.= fgets($this->fsock, 255);
+        }
+
+        $ext = array();
+        if (extension_loaded('mcrypt')) {
+            $ext[] = 'mcrypt';
+        }
+        if (extension_loaded('gmp')) {
+            $ext[] = 'gmp';
+        } else if (extension_loaded('bcmath')) {
+            $ext[] = 'bcmath';
+        }
+
+        if (!empty($ext)) {
+            $this->identifier.= ' (' . implode(', ', $ext) . ')';
+        }
+
+        if (defined('NET_SSH2_LOGGING')) {
+            $this->message_number_log[] = '<-';
+            $this->message_number_log[] = '->';
+
+            if (NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX) {
+                $this->message_log[] = $temp;
+                $this->message_log[] = $this->identifier . "\r\n";
+            }
+        }
+
+        $this->server_identifier = trim($temp, "\r\n");
+        if (!empty($extra)) {
+            $this->errors[] = utf8_decode($extra);
+        }
+
+        if ($matches[1] != '1.99' && $matches[1] != '2.0') {
+            user_error("Cannot connect to SSH $matches[1] servers", E_USER_NOTICE);
+            return;
+        }
+
+        fputs($this->fsock, $this->identifier . "\r\n");
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return;
+        }
+
+        if (ord($response[0]) != NET_SSH2_MSG_KEXINIT) {
+            user_error('Expected SSH_MSG_KEXINIT', E_USER_NOTICE);
+            return;
+        }
+
+        if (!$this->_key_exchange($response)) {
+            return;
+        }
+
+        $this->bitmap = NET_SSH2_MASK_CONSTRUCTOR;
+    }
+
+    /**
+     * Key Exchange
+     *
+     * @param String $kexinit_payload_server
+     * @access private
+     */
+    function _key_exchange($kexinit_payload_server)
+    {
+        static $kex_algorithms = array(
+            'diffie-hellman-group1-sha1', // REQUIRED
+            'diffie-hellman-group14-sha1' // REQUIRED
+        );
+
+        static $server_host_key_algorithms = array(
+            'ssh-rsa', // RECOMMENDED  sign   Raw RSA Key
+            'ssh-dss'  // REQUIRED     sign   Raw DSS Key
+        );
+
+        static $encryption_algorithms = array(
+            // from <http://tools.ietf.org/html/rfc4345#section-4>:
+            'arcfour256',
+            'arcfour128',
+
+            'arcfour',    // OPTIONAL          the ARCFOUR stream cipher with a 128-bit key
+
+            'aes128-cbc', // RECOMMENDED       AES with a 128-bit key
+            'aes192-cbc', // OPTIONAL          AES with a 192-bit key
+            'aes256-cbc', // OPTIONAL          AES in CBC mode, with a 256-bit key
+
+            // from <http://tools.ietf.org/html/rfc4344#section-4>:
+            'aes128-ctr', // RECOMMENDED       AES (Rijndael) in SDCTR mode, with 128-bit key
+            'aes192-ctr', // RECOMMENDED       AES with 192-bit key
+            'aes256-ctr', // RECOMMENDED       AES with 256-bit key
+            '3des-ctr',   // RECOMMENDED       Three-key 3DES in SDCTR mode
+
+            '3des-cbc',   // REQUIRED          three-key 3DES in CBC mode
+            'none'        // OPTIONAL          no encryption; NOT RECOMMENDED
+        );
+
+        static $mac_algorithms = array(
+            'hmac-sha1-96', // RECOMMENDED     first 96 bits of HMAC-SHA1 (digest length = 12, key length = 20)
+            'hmac-sha1',    // REQUIRED        HMAC-SHA1 (digest length = key length = 20)
+            'hmac-md5-96',  // OPTIONAL        first 96 bits of HMAC-MD5 (digest length = 12, key length = 16)
+            'hmac-md5',     // OPTIONAL        HMAC-MD5 (digest length = key length = 16)
+            'none'          // OPTIONAL        no MAC; NOT RECOMMENDED
+        );
+
+        static $compression_algorithms = array(
+            'none'   // REQUIRED        no compression
+            //'zlib' // OPTIONAL        ZLIB (LZ77) compression
+        );
+
+        static $str_kex_algorithms, $str_server_host_key_algorithms,
+               $encryption_algorithms_server_to_client, $mac_algorithms_server_to_client, $compression_algorithms_server_to_client,
+               $encryption_algorithms_client_to_server, $mac_algorithms_client_to_server, $compression_algorithms_client_to_server;
+
+        if (empty($str_kex_algorithms)) {
+            $str_kex_algorithms = implode(',', $kex_algorithms);
+            $str_server_host_key_algorithms = implode(',', $server_host_key_algorithms);
+            $encryption_algorithms_server_to_client = $encryption_algorithms_client_to_server = implode(',', $encryption_algorithms);
+            $mac_algorithms_server_to_client = $mac_algorithms_client_to_server = implode(',', $mac_algorithms);
+            $compression_algorithms_server_to_client = $compression_algorithms_client_to_server = implode(',', $compression_algorithms);
+        }
+
+        $client_cookie = '';
+        for ($i = 0; $i < 16; $i++) {
+            $client_cookie.= chr(crypt_random(0, 255));
+        }
+
+        $response = $kexinit_payload_server;
+        $this->_string_shift($response, 1); // skip past the message number (it should be SSH_MSG_KEXINIT)
+        $server_cookie = $this->_string_shift($response, 16);
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->kex_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->server_host_key_algorithms = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->encryption_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->encryption_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->mac_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->mac_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->compression_algorithms_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->compression_algorithms_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->languages_client_to_server = explode(',', $this->_string_shift($response, $temp['length']));
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->languages_server_to_client = explode(',', $this->_string_shift($response, $temp['length']));
+
+        extract(unpack('Cfirst_kex_packet_follows', $this->_string_shift($response, 1)));
+        $first_kex_packet_follows = $first_kex_packet_follows != 0;
+
+        // the sending of SSH2_MSG_KEXINIT could go in one of two places.  this is the second place.
+        $kexinit_payload_client = pack('Ca*Na*Na*Na*Na*Na*Na*Na*Na*Na*Na*CN',
+            NET_SSH2_MSG_KEXINIT, $client_cookie, strlen($str_kex_algorithms), $str_kex_algorithms,
+            strlen($str_server_host_key_algorithms), $str_server_host_key_algorithms, strlen($encryption_algorithms_client_to_server),
+            $encryption_algorithms_client_to_server, strlen($encryption_algorithms_server_to_client), $encryption_algorithms_server_to_client,
+            strlen($mac_algorithms_client_to_server), $mac_algorithms_client_to_server, strlen($mac_algorithms_server_to_client),
+            $mac_algorithms_server_to_client, strlen($compression_algorithms_client_to_server), $compression_algorithms_client_to_server,
+            strlen($compression_algorithms_server_to_client), $compression_algorithms_server_to_client, 0, '', 0, '',
+            0, 0
+        );
+
+        if (!$this->_send_binary_packet($kexinit_payload_client)) {
+            return false;
+        }
+        // here ends the second place.
+
+        // we need to decide upon the symmetric encryption algorithms before we do the diffie-hellman key exchange
+        for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_server_to_client); $i++);
+        if ($i == count($encryption_algorithms)) {
+            user_error('No compatible server to client encryption algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        // we don't initialize any crypto-objects, yet - we do that, later. for now, we need the lengths to make the
+        // diffie-hellman key exchange as fast as possible
+        $decrypt = $encryption_algorithms[$i];
+        switch ($decrypt) {
+            case '3des-cbc':
+            case '3des-ctr':
+                $decryptKeyLength = 24; // eg. 192 / 8
+                break;
+            case 'aes256-cbc':
+            case 'aes256-ctr':
+                $decryptKeyLength = 32; // eg. 256 / 8
+                break;
+            case 'aes192-cbc':
+            case 'aes192-ctr':
+                $decryptKeyLength = 24; // eg. 192 / 8
+                break;
+            case 'aes128-cbc':
+            case 'aes128-ctr':
+                $decryptKeyLength = 16; // eg. 128 / 8
+                break;
+            case 'arcfour':
+            case 'arcfour128':
+                $decryptKeyLength = 16; // eg. 128 / 8
+                break;
+            case 'arcfour256':
+                $decryptKeyLength = 32; // eg. 128 / 8
+                break;
+            case 'none';
+                $decryptKeyLength = 0;
+        }
+
+        for ($i = 0; $i < count($encryption_algorithms) && !in_array($encryption_algorithms[$i], $this->encryption_algorithms_client_to_server); $i++);
+        if ($i == count($encryption_algorithms)) {
+            user_error('No compatible client to server encryption algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        $encrypt = $encryption_algorithms[$i];
+        switch ($encrypt) {
+            case '3des-cbc':
+            case '3des-ctr':
+                $encryptKeyLength = 24;
+                break;
+            case 'aes256-cbc':
+            case 'aes256-ctr':
+                $encryptKeyLength = 32;
+                break;
+            case 'aes192-cbc':
+            case 'aes192-ctr':
+                $encryptKeyLength = 24;
+                break;
+            case 'aes128-cbc':
+            case 'aes128-ctr':
+                $encryptKeyLength = 16;
+                break;
+            case 'arcfour':
+            case 'arcfour128':
+                $encryptKeyLength = 16;
+                break;
+            case 'arcfour256':
+                $encryptKeyLength = 32;
+                break;
+            case 'none';
+                $encryptKeyLength = 0;
+        }
+
+        $keyLength = $decryptKeyLength > $encryptKeyLength ? $decryptKeyLength : $encryptKeyLength;
+
+        // through diffie-hellman key exchange a symmetric key is obtained
+        for ($i = 0; $i < count($kex_algorithms) && !in_array($kex_algorithms[$i], $this->kex_algorithms); $i++);
+        if ($i == count($kex_algorithms)) {
+            user_error('No compatible key exchange algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        switch ($kex_algorithms[$i]) {
+            // see http://tools.ietf.org/html/rfc2409#section-6.2 and 
+            // http://tools.ietf.org/html/rfc2412, appendex E
+            case 'diffie-hellman-group1-sha1':
+                $p = pack('H256', 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . 
+                                  '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . 
+                                  '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 
+                                  'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF');
+                $keyLength = $keyLength < 160 ? $keyLength : 160;
+                $hash = 'sha1';
+                break;
+            // see http://tools.ietf.org/html/rfc3526#section-3
+            case 'diffie-hellman-group14-sha1':
+                $p = pack('H512', 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74' . 
+                                  '020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F1437' . 
+                                  '4FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' . 
+                                  'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF05' . 
+                                  '98DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB' . 
+                                  '9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' . 
+                                  'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718' . 
+                                  '3995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF');
+                $keyLength = $keyLength < 160 ? $keyLength : 160;
+                $hash = 'sha1';
+        }
+
+        $p = new Math_BigInteger($p, 256);
+        //$q = $p->bitwise_rightShift(1);
+
+        /* To increase the speed of the key exchange, both client and server may
+           reduce the size of their private exponents.  It should be at least
+           twice as long as the key material that is generated from the shared
+           secret.  For more details, see the paper by van Oorschot and Wiener
+           [VAN-OORSCHOT].
+
+           -- http://tools.ietf.org/html/rfc4419#section-6.2 */
+        $q = new Math_BigInteger(1);
+        $q = $q->bitwise_leftShift(2 * $keyLength);
+        $q = $q->subtract(new Math_BigInteger(1));
+
+        $g = new Math_BigInteger(2);
+        $x = new Math_BigInteger();
+        $x->setRandomGenerator('crypt_random');
+        $x = $x->random(new Math_BigInteger(1), $q);
+        $e = $g->modPow($x, $p);
+
+        $eBytes = $e->toBytes(true);
+        $data = pack('CNa*', NET_SSH2_MSG_KEXDH_INIT, strlen($eBytes), $eBytes);
+
+        if (!$this->_send_binary_packet($data)) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        if ($type != NET_SSH2_MSG_KEXDH_REPLY) {
+            user_error('Expected SSH_MSG_KEXDH_REPLY', E_USER_NOTICE);
+            return false;
+        }
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->server_public_host_key = $server_public_host_key = $this->_string_shift($response, $temp['length']);
+
+        $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+        $public_key_format = $this->_string_shift($server_public_host_key, $temp['length']);
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $fBytes = $this->_string_shift($response, $temp['length']);
+        $f = new Math_BigInteger($fBytes, -256);
+
+        $temp = unpack('Nlength', $this->_string_shift($response, 4));
+        $this->signature = $this->_string_shift($response, $temp['length']);
+
+        $temp = unpack('Nlength', $this->_string_shift($this->signature, 4));
+        $this->signature_format = $this->_string_shift($this->signature, $temp['length']);
+
+        $key = $f->modPow($x, $p);
+        $keyBytes = $key->toBytes(true);
+
+        if ($this->session_id === false) {
+            $source = pack('Na*Na*Na*Na*Na*Na*Na*Na*',
+                strlen($this->identifier), $this->identifier, strlen($this->server_identifier), $this->server_identifier,
+                strlen($kexinit_payload_client), $kexinit_payload_client, strlen($kexinit_payload_server),
+                $kexinit_payload_server, strlen($this->server_public_host_key), $this->server_public_host_key, strlen($eBytes),
+                $eBytes, strlen($fBytes), $fBytes, strlen($keyBytes), $keyBytes
+            );
+
+            $source = pack('H*', $hash($source));
+
+            $this->session_id = $source;
+        }
+
+        for ($i = 0; $i < count($server_host_key_algorithms) && !in_array($server_host_key_algorithms[$i], $this->server_host_key_algorithms); $i++);
+        if ($i == count($server_host_key_algorithms)) {
+            user_error('No compatible server host key algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        if ($public_key_format != $server_host_key_algorithms[$i] || $this->signature_format != $server_host_key_algorithms[$i]) {
+            user_error('Sever Host Key Algorithm Mismatch', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        $packet = pack('C',
+            NET_SSH2_MSG_NEWKEYS
+        );
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        if ($type != NET_SSH2_MSG_NEWKEYS) {
+            user_error('Expected SSH_MSG_NEWKEYS', E_USER_NOTICE);
+            return false;
+        }
+
+        switch ($encrypt) {
+            case '3des-cbc':
+                $this->encrypt = new Crypt_TripleDES();
+                // $this->encrypt_block_size = 64 / 8 == the default
+                break;
+            case '3des-ctr':
+                $this->encrypt = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
+                // $this->encrypt_block_size = 64 / 8 == the default
+                break;
+            case 'aes256-cbc':
+            case 'aes192-cbc':
+            case 'aes128-cbc':
+                $this->encrypt = new Crypt_AES();
+                $this->encrypt_block_size = 16; // eg. 128 / 8
+                break;
+            case 'aes256-ctr':
+            case 'aes192-ctr':
+            case 'aes128-ctr':
+                $this->encrypt = new Crypt_AES(CRYPT_AES_MODE_CTR);
+                $this->encrypt_block_size = 16; // eg. 128 / 8
+                break;
+            case 'arcfour':
+            case 'arcfour128':
+            case 'arcfour256':
+                $this->encrypt = new Crypt_RC4();
+                break;
+            case 'none';
+                //$this->encrypt = new Crypt_Null();
+        }
+
+        switch ($decrypt) {
+            case '3des-cbc':
+                $this->decrypt = new Crypt_TripleDES();
+                break;
+            case '3des-ctr':
+                $this->decrypt = new Crypt_TripleDES(CRYPT_DES_MODE_CTR);
+                break;
+            case 'aes256-cbc':
+            case 'aes192-cbc':
+            case 'aes128-cbc':
+                $this->decrypt = new Crypt_AES();
+                $this->decrypt_block_size = 16;
+                break;
+            case 'aes256-ctr':
+            case 'aes192-ctr':
+            case 'aes128-ctr':
+                $this->decrypt = new Crypt_AES(CRYPT_AES_MODE_CTR);
+                $this->decrypt_block_size = 16;
+                break;
+            case 'arcfour':
+            case 'arcfour128':
+            case 'arcfour256':
+                $this->decrypt = new Crypt_RC4();
+                break;
+            case 'none';
+                //$this->decrypt = new Crypt_Null();
+        }
+
+        $keyBytes = pack('Na*', strlen($keyBytes), $keyBytes);
+
+        if ($this->encrypt) {
+            $this->encrypt->enableContinuousBuffer();
+            $this->encrypt->disablePadding();
+
+            $iv = pack('H*', $hash($keyBytes . $this->session_id . 'A' . $this->session_id));
+            while ($this->encrypt_block_size > strlen($iv)) {
+                $iv.= pack('H*', $hash($keyBytes . $this->session_id . $iv));
+            }
+            $this->encrypt->setIV(substr($iv, 0, $this->encrypt_block_size));
+
+            $key = pack('H*', $hash($keyBytes . $this->session_id . 'C' . $this->session_id));
+            while ($encryptKeyLength > strlen($key)) {
+                $key.= pack('H*', $hash($keyBytes . $this->session_id . $key));
+            }
+            $this->encrypt->setKey(substr($key, 0, $encryptKeyLength));
+        }
+
+        if ($this->decrypt) {
+            $this->decrypt->enableContinuousBuffer();
+            $this->decrypt->disablePadding();
+
+            $iv = pack('H*', $hash($keyBytes . $this->session_id . 'B' . $this->session_id));
+            while ($this->decrypt_block_size > strlen($iv)) {
+                $iv.= pack('H*', $hash($keyBytes . $this->session_id . $iv));
+            }
+            $this->decrypt->setIV(substr($iv, 0, $this->decrypt_block_size));
+
+            $key = pack('H*', $hash($keyBytes . $this->session_id . 'D' . $this->session_id));
+            while ($decryptKeyLength > strlen($key)) {
+                $key.= pack('H*', $hash($keyBytes . $this->session_id . $key));
+            }
+            $this->decrypt->setKey(substr($key, 0, $decryptKeyLength));
+        }
+
+        /* The "arcfour128" algorithm is the RC4 cipher, as described in
+           [SCHNEIER], using a 128-bit key.  The first 1536 bytes of keystream
+           generated by the cipher MUST be discarded, and the first byte of the
+           first encrypted packet MUST be encrypted using the 1537th byte of
+           keystream.
+
+           -- http://tools.ietf.org/html/rfc4345#section-4 */
+        if ($encrypt == 'arcfour128' || $encrypt == 'arcfour256') {
+            $this->encrypt->encrypt(str_repeat("\0", 1536));
+        }
+        if ($decrypt == 'arcfour128' || $decrypt == 'arcfour256') {
+            $this->decrypt->decrypt(str_repeat("\0", 1536));
+        }
+
+        for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_client_to_server); $i++);
+        if ($i == count($mac_algorithms)) {
+            user_error('No compatible client to server message authentication algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        $createKeyLength = 0; // ie. $mac_algorithms[$i] == 'none'
+        switch ($mac_algorithms[$i]) {
+            case 'hmac-sha1':
+                $this->hmac_create = new Crypt_Hash('sha1');
+                $createKeyLength = 20;
+                break;
+            case 'hmac-sha1-96':
+                $this->hmac_create = new Crypt_Hash('sha1-96');
+                $createKeyLength = 20;
+                break;
+            case 'hmac-md5':
+                $this->hmac_create = new Crypt_Hash('md5');
+                $createKeyLength = 16;
+                break;
+            case 'hmac-md5-96':
+                $this->hmac_create = new Crypt_Hash('md5-96');
+                $createKeyLength = 16;
+        }
+
+        for ($i = 0; $i < count($mac_algorithms) && !in_array($mac_algorithms[$i], $this->mac_algorithms_server_to_client); $i++);
+        if ($i == count($mac_algorithms)) {
+            user_error('No compatible server to client message authentication algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+
+        $checkKeyLength = 0;
+        $this->hmac_size = 0;
+        switch ($mac_algorithms[$i]) {
+            case 'hmac-sha1':
+                $this->hmac_check = new Crypt_Hash('sha1');
+                $checkKeyLength = 20;
+                $this->hmac_size = 20;
+                break;
+            case 'hmac-sha1-96':
+                $this->hmac_check = new Crypt_Hash('sha1-96');
+                $checkKeyLength = 20;
+                $this->hmac_size = 12;
+                break;
+            case 'hmac-md5':
+                $this->hmac_check = new Crypt_Hash('md5');
+                $checkKeyLength = 16;
+                $this->hmac_size = 16;
+                break;
+            case 'hmac-md5-96':
+                $this->hmac_check = new Crypt_Hash('md5-96');
+                $checkKeyLength = 16;
+                $this->hmac_size = 12;
+        }
+
+        $key = pack('H*', $hash($keyBytes . $this->session_id . 'E' . $this->session_id));
+        while ($createKeyLength > strlen($key)) {
+            $key.= pack('H*', $hash($keyBytes . $this->session_id . $key));
+        }
+        $this->hmac_create->setKey(substr($key, 0, $createKeyLength));
+
+        $key = pack('H*', $hash($keyBytes . $this->session_id . 'F' . $this->session_id));
+        while ($checkKeyLength > strlen($key)) {
+            $key.= pack('H*', $hash($keyBytes . $this->session_id . $key));
+        }
+        $this->hmac_check->setKey(substr($key, 0, $checkKeyLength));
+
+        for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_server_to_client); $i++);
+        if ($i == count($compression_algorithms)) {
+            user_error('No compatible server to client compression algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+        $this->decompress = $compression_algorithms[$i] == 'zlib';
+
+        for ($i = 0; $i < count($compression_algorithms) && !in_array($compression_algorithms[$i], $this->compression_algorithms_client_to_server); $i++);
+        if ($i == count($compression_algorithms)) {
+            user_error('No compatible client to server compression algorithms found', E_USER_NOTICE);
+            return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+        }
+        $this->compress = $compression_algorithms[$i] == 'zlib';
+
+        return true;
+    }
+
+    /**
+     * Login
+     *
+     * @param String $username
+     * @param optional String $password
+     * @return Boolean
+     * @access public
+     * @internal It might be worthwhile, at some point, to protect against {@link http://tools.ietf.org/html/rfc4251#section-9.3.9 traffic analysis}
+     *           by sending dummy SSH_MSG_IGNORE messages.
+     */
+    function login($username, $password = '')
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR)) {
+            return false;
+        }
+
+        $packet = pack('CNa*',
+            NET_SSH2_MSG_SERVICE_REQUEST, strlen('ssh-userauth'), 'ssh-userauth'
+        );
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        if ($type != NET_SSH2_MSG_SERVICE_ACCEPT) {
+            user_error('Expected SSH_MSG_SERVICE_ACCEPT', E_USER_NOTICE);
+            return false;
+        }
+
+        // although PHP5's get_class() preserves the case, PHP4's does not
+        if (is_object($password) && strtolower(get_class($password)) == 'crypt_rsa')  {
+            return $this->_privatekey_login($username, $password);
+        }
+
+        $utf8_password = utf8_encode($password);
+        $packet = pack('CNa*Na*Na*CNa*',
+            NET_SSH2_MSG_USERAUTH_REQUEST, strlen($username), $username, strlen('ssh-connection'), 'ssh-connection',
+            strlen('password'), 'password', 0, strlen($utf8_password), $utf8_password
+        );
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        // remove the username and password from the last logged packet
+        if (defined('NET_SSH2_LOGGING') && NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX) {
+            $packet = pack('CNa*Na*Na*CNa*',
+                NET_SSH2_MSG_USERAUTH_REQUEST, strlen('username'), 'username', strlen('ssh-connection'), 'ssh-connection',
+                strlen('password'), 'password', 0, strlen('password'), 'password'
+            );
+            $this->message_log[count($this->message_log) - 1] = $packet;
+        }
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        switch ($type) {
+            case NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: // in theory, the password can be changed
+                if (defined('NET_SSH2_LOGGING')) {
+                    $this->message_number_log[count($this->message_number_log) - 1] = 'NET_SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ';
+                }
+                extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                $this->errors[] = 'SSH_MSG_USERAUTH_PASSWD_CHANGEREQ: ' . utf8_decode($this->_string_shift($response, $length));
+                return $this->_disconnect(NET_SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER);
+            case NET_SSH2_MSG_USERAUTH_FAILURE:
+                // either the login is bad or the server employees multi-factor authentication
+                return false;
+            case NET_SSH2_MSG_USERAUTH_SUCCESS:
+                $this->bitmap |= NET_SSH2_MASK_LOGIN;
+                return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Login with an RSA private key
+     *
+     * @param String $username
+     * @param Crypt_RSA $password
+     * @return Boolean
+     * @access private
+     * @internal It might be worthwhile, at some point, to protect against {@link http://tools.ietf.org/html/rfc4251#section-9.3.9 traffic analysis}
+     *           by sending dummy SSH_MSG_IGNORE messages.
+     */
+    function _privatekey_login($username, $privatekey)
+    {
+        // see http://tools.ietf.org/html/rfc4253#page-15
+        $publickey = $privatekey->getPublicKey(CRYPT_RSA_PUBLIC_FORMAT_RAW);
+        if ($publickey === false) {
+            return false;
+        }
+
+        $publickey = array(
+            'e' => $publickey['e']->toBytes(true),
+            'n' => $publickey['n']->toBytes(true)
+        );
+        $publickey = pack('Na*Na*Na*',
+            strlen('ssh-rsa'), 'ssh-rsa', strlen($publickey['e']), $publickey['e'], strlen($publickey['n']), $publickey['n']
+        );
+
+        $part1 = pack('CNa*Na*Na*',
+            NET_SSH2_MSG_USERAUTH_REQUEST, strlen($username), $username, strlen('ssh-connection'), 'ssh-connection',
+            strlen('publickey'), 'publickey'
+        );
+        $part2 = pack('Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($publickey), $publickey);
+
+        $packet = $part1 . chr(0) . $part2;
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        switch ($type) {
+            case NET_SSH2_MSG_USERAUTH_FAILURE:
+                extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                $this->errors[] = 'SSH_MSG_USERAUTH_FAILURE: ' . $this->_string_shift($response, $length);
+                return $this->_disconnect(NET_SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER);
+            case NET_SSH2_MSG_USERAUTH_PK_OK:
+                // we'll just take it on faith that the public key blob and the public key algorithm name are as
+                // they should be
+                if (defined('NET_SSH2_LOGGING')) {
+                    $this->message_number_log[count($this->message_number_log) - 1] = 'NET_SSH2_MSG_USERAUTH_PK_OK';
+                }
+        }
+
+        $packet = $part1 . chr(1) . $part2;
+        $privatekey->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
+        $signature = $privatekey->sign(pack('Na*a*', strlen($this->session_id), $this->session_id, $packet));
+        $signature = pack('Na*Na*', strlen('ssh-rsa'), 'ssh-rsa', strlen($signature), $signature);
+        $packet.= pack('Na*', strlen($signature), $signature);
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $response = $this->_get_binary_packet();
+        if ($response === false) {
+            user_error('Connection closed by server', E_USER_NOTICE);
+            return false;
+        }
+
+        extract(unpack('Ctype', $this->_string_shift($response, 1)));
+
+        switch ($type) {
+            case NET_SSH2_MSG_USERAUTH_FAILURE:
+                // either the login is bad or the server employees multi-factor authentication
+                return false;
+            case NET_SSH2_MSG_USERAUTH_SUCCESS:
+                $this->bitmap |= NET_SSH2_MASK_LOGIN;
+                return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Execute Command
+     *
+     * @param String $command
+     * @return String
+     * @access public
+     */
+    function exec($command)
+    {
+        if (!($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            return false;
+        }
+
+        // RFC4254 defines the (client) window size as "bytes the other party can send before it must wait for the window to
+        // be adjusted".  0x7FFFFFFF is, at 4GB, the max size.  technically, it should probably be decremented, but, 
+        // honestly, if you're transfering more than 4GB, you probably shouldn't be using phpseclib, anyway.
+        // see http://tools.ietf.org/html/rfc4254#section-5.2 for more info
+        $this->window_size_client_to_server[NET_SSH2_CHANNEL_EXEC] = 0x7FFFFFFF;
+        // 0x8000 is the maximum max packet size, per http://tools.ietf.org/html/rfc4253#section-6.1, although since PuTTy
+        // uses 0x4000, that's what will be used here, as well.
+        $packet_size = 0x4000;
+
+        $packet = pack('CNa*N3',
+            NET_SSH2_MSG_CHANNEL_OPEN, strlen('session'), 'session', NET_SSH2_CHANNEL_EXEC, $this->window_size_client_to_server[NET_SSH2_CHANNEL_EXEC], $packet_size);
+
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $this->channel_status[NET_SSH2_CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_OPEN;
+
+        $response = $this->_get_channel_packet(NET_SSH2_CHANNEL_EXEC);
+        if ($response === false) {
+            return false;
+        }
+
+        // sending a pty-req SSH_MSG_CHANNEL_REQUEST message is unnecessary and, in fact, in most cases, slows things
+        // down.  the one place where it might be desirable is if you're doing something like Net_SSH2::exec('ping localhost &').
+        // with a pty-req SSH_MSG_cHANNEL_REQUEST, exec() will return immediately and the ping process will then
+        // then immediately terminate.  without such a request exec() will loop indefinitely.  the ping process won't end but
+        // neither will your script.
+
+        // although, in theory, the size of SSH_MSG_CHANNEL_REQUEST could exceed the maximum packet size established by
+        // SSH_MSG_CHANNEL_OPEN_CONFIRMATION, RFC4254#section-5.1 states that the "maximum packet size" refers to the 
+        // "maximum size of an individual data packet". ie. SSH_MSG_CHANNEL_DATA.  RFC4254#section-5.2 corroborates.
+        $packet = pack('CNNa*CNa*',
+            NET_SSH2_MSG_CHANNEL_REQUEST, $this->server_channels[NET_SSH2_CHANNEL_EXEC], strlen('exec'), 'exec', 1, strlen($command), $command);
+        if (!$this->_send_binary_packet($packet)) {
+            return false;
+        }
+
+        $this->channel_status[NET_SSH2_CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_REQUEST;
+
+        $response = $this->_get_channel_packet(NET_SSH2_CHANNEL_EXEC);
+        if ($response === false) {
+            return false;
+        }
+
+        $this->channel_status[NET_SSH2_CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_DATA;
+
+        $output = '';
+        while (true) {
+            $temp = $this->_get_channel_packet(NET_SSH2_CHANNEL_EXEC);
+            switch (true) {
+                case $temp === true:
+                    return $output;
+                case $temp === false:
+                    return false;
+                default:
+                    $output.= $temp;
+            }
+        }
+    }
+
+    /**
+     * Disconnect
+     *
+     * @access public
+     */
+    function disconnect()
+    {
+        $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+    }
+
+    /**
+     * Destructor.
+     *
+     * Will be called, automatically, if you're supporting just PHP5.  If you're supporting PHP4, you'll need to call
+     * disconnect().
+     *
+     * @access public
+     */
+    function __destruct()
+    {
+        $this->disconnect();
+    }
+
+    /**
+     * Gets Binary Packets
+     *
+     * See '6. Binary Packet Protocol' of rfc4253 for more info.
+     *
+     * @see Net_SSH2::_send_binary_packet()
+     * @return String
+     * @access private
+     */
+    function _get_binary_packet()
+    {
+        if (feof($this->fsock)) {
+            user_error('Connection closed prematurely', E_USER_NOTICE);
+            return false;
+        }
+
+        $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
+        $raw = fread($this->fsock, $this->decrypt_block_size);
+        $stop = strtok(microtime(), ' ') + strtok('');
+
+        if ($this->decrypt !== false) {
+            $raw = $this->decrypt->decrypt($raw);
+        }
+
+        extract(unpack('Npacket_length/Cpadding_length', $this->_string_shift($raw, 5)));
+
+        $remaining_length = $packet_length + 4 - $this->decrypt_block_size;
+        $buffer = '';
+        while ($remaining_length > 0) {
+            $temp = fread($this->fsock, $remaining_length);
+            $buffer.= $temp;
+            $remaining_length-= strlen($temp);
+        }
+        if (!empty($buffer)) {
+            $raw.= $this->decrypt !== false ? $this->decrypt->decrypt($buffer) : $buffer;
+            $buffer = $temp = '';
+        }
+
+        $payload = $this->_string_shift($raw, $packet_length - $padding_length - 1);
+        $padding = $this->_string_shift($raw, $padding_length); // should leave $raw empty
+
+        if ($this->hmac_check !== false) {
+            $hmac = fread($this->fsock, $this->hmac_size);
+            if ($hmac != $this->hmac_check->hash(pack('NNCa*', $this->get_seq_no, $packet_length, $padding_length, $payload . $padding))) {
+                user_error('Invalid HMAC', E_USER_NOTICE);
+                return false;
+            }
+        }
+
+        //if ($this->decompress) {
+        //    $payload = gzinflate(substr($payload, 2));
+        //}
+
+        $this->get_seq_no++;
+
+        if (defined('NET_SSH2_LOGGING')) {
+            $temp = isset($this->message_numbers[ord($payload[0])]) ? $this->message_numbers[ord($payload[0])] : 'UNKNOWN';
+            $this->message_number_log[] = '<- ' . $temp .
+                                          ' (' . round($stop - $start, 4) . 's)';
+            if (NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX) {
+                $this->message_log[] = substr($payload, 1);
+            }
+        }
+
+        return $this->_filter($payload);
+    }
+
+    /**
+     * Filter Binary Packets
+     *
+     * Because some binary packets need to be ignored...
+     *
+     * @see Net_SSH2::_get_binary_packet()
+     * @return String
+     * @access private
+     */
+    function _filter($payload)
+    {
+        switch (ord($payload[0])) {
+            case NET_SSH2_MSG_DISCONNECT:
+                $this->_string_shift($payload, 1);
+                extract(unpack('Nreason_code/Nlength', $this->_string_shift($payload, 8)));
+                $this->errors[] = 'SSH_MSG_DISCONNECT: ' . $this->disconnect_reasons[$reason_code] . "\r\n" . utf8_decode($this->_string_shift($payload, $length));
+                $this->bitmask = 0;
+                return false;
+            case NET_SSH2_MSG_IGNORE:
+                $payload = $this->_get_binary_packet();
+                break;
+            case NET_SSH2_MSG_DEBUG:
+                $this->_string_shift($payload, 2);
+                extract(unpack('Nlength', $this->_string_shift($payload, 4)));
+                $this->errors[] = 'SSH_MSG_DEBUG: ' . utf8_decode($this->_string_shift($payload, $length));
+                $payload = $this->_get_binary_packet();
+                break;
+            case NET_SSH2_MSG_UNIMPLEMENTED:
+                return false;
+            case NET_SSH2_MSG_KEXINIT:
+                if ($this->session_id !== false) {
+                    if (!$this->_key_exchange($payload)) {
+                        $this->bitmask = 0;
+                        return false;
+                    }
+                    $payload = $this->_get_binary_packet();
+                }
+        }
+
+        // see http://tools.ietf.org/html/rfc4252#section-5.4; only called when the encryption has been activated and when we haven't already logged in
+        if (($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR) && !($this->bitmap & NET_SSH2_MASK_LOGIN) && ord($payload[0]) == NET_SSH2_MSG_USERAUTH_BANNER) {
+            $this->_string_shift($payload, 1);
+            extract(unpack('Nlength', $this->_string_shift($payload, 4)));
+            $this->errors[] = 'SSH_MSG_USERAUTH_BANNER: ' . utf8_decode($this->_string_shift($payload, $length));
+            $payload = $this->_get_binary_packet();
+        }
+
+        // only called when we've already logged in
+        if (($this->bitmap & NET_SSH2_MASK_CONSTRUCTOR) && ($this->bitmap & NET_SSH2_MASK_LOGIN)) {
+            switch (ord($payload[0])) {
+                case NET_SSH2_MSG_GLOBAL_REQUEST: // see http://tools.ietf.org/html/rfc4254#section-4
+                    $this->_string_shift($payload, 1);
+                    extract(unpack('Nlength', $this->_string_shift($payload)));
+                    $this->errors[] = 'SSH_MSG_GLOBAL_REQUEST: ' . utf8_decode($this->_string_shift($payload, $length));
+
+                    if (!$this->_send_binary_packet(pack('C', NET_SSH2_MSG_REQUEST_FAILURE))) {
+                        return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+                    }
+
+                    $payload = $this->_get_binary_packet();
+                    break;
+                case NET_SSH2_MSG_CHANNEL_OPEN: // see http://tools.ietf.org/html/rfc4254#section-5.1
+                    $this->_string_shift($payload, 1);
+                    extract(unpack('N', $this->_string_shift($payload, 4)));
+                    $this->errors[] = 'SSH_MSG_CHANNEL_OPEN: ' . utf8_decode($this->_string_shift($payload, $length));
+
+                    $this->_string_shift($payload, 4); // skip over client channel
+                    extract(unpack('Nserver_channel', $this->_string_shift($payload, 4)));
+
+                    $packet = pack('CN3a*Na*',
+                        NET_SSH2_MSG_REQUEST_FAILURE, $server_channel, NET_SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED, 0, '', 0, '');
+
+                    if (!$this->_send_binary_packet($packet)) {
+                        return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+                    }
+
+                    $payload = $this->_get_binary_packet();
+                    break;
+                case NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST:
+                    $payload = $this->_get_binary_packet();
+            }
+        }
+
+        return $payload;
+    }
+
+    /**
+     * Gets channel data
+     *
+     * Returns the data as a string if it's available and false if not.
+     *
+     * @param $client_channel
+     * @return Mixed
+     * @access private
+     */
+    function _get_channel_packet($client_channel)
+    {
+        if (!empty($this->channel_buffers[$client_channel])) {
+            return array_shift($this->channel_buffers[$client_channel]);
+        }
+
+        while (true) {
+            $response = $this->_get_binary_packet();
+            if ($response === false) {
+                user_error('Connection closed by server', E_USER_NOTICE);
+                return false;
+            }
+
+            extract(unpack('Ctype/Nchannel', $this->_string_shift($response, 5)));
+
+            switch ($this->channel_status[$channel]) {
+                case NET_SSH2_MSG_CHANNEL_OPEN:
+                    switch ($type) {
+                        case NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
+                            extract(unpack('Nserver_channel', $this->_string_shift($response, 4)));
+                            $this->server_channels[$client_channel] = $server_channel;
+                            $this->_string_shift($response, 4); // skip over (server) window size
+                            $temp = unpack('Npacket_size_client_to_server', $this->_string_shift($response, 4));
+                            $this->packet_size_client_to_server[$client_channel] = $temp['packet_size_client_to_server'];
+                            return true;
+                        //case NET_SSH2_MSG_CHANNEL_OPEN_FAILURE:
+                        default:
+                            user_error('Unable to open channel', E_USER_NOTICE);
+                            return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+                    }
+                    break;
+                case NET_SSH2_MSG_CHANNEL_REQUEST:
+                    switch ($type) {
+                        case NET_SSH2_MSG_CHANNEL_SUCCESS:
+                            return true;
+                        //case NET_SSH2_MSG_CHANNEL_FAILURE:
+                        default:
+                            user_error('Unable to request pseudo-terminal', E_USER_NOTICE);
+                            return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+                    }
+
+            }
+
+            switch ($type) {
+                case NET_SSH2_MSG_CHANNEL_DATA:
+                    if ($client_channel == NET_SSH2_CHANNEL_EXEC) {
+                        // SCP requires null packets, such as this, be sent.  further, in the case of the ssh.com SSH server
+                        // this actually seems to make things twice as fast.  more to the point, the message right after 
+                        // SSH_MSG_CHANNEL_DATA (usually SSH_MSG_IGNORE) won't block for as long as it would have otherwise.
+                        // in OpenSSH it slows things down but only by a couple thousandths of a second.
+                        $this->_send_channel_packet($client_channel, chr(0));
+                    }
+                    extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                    $data = $this->_string_shift($response, $length);
+                    if ($client_channel == $channel) {
+                        return $data;
+                    }
+                    if (!isset($this->channel_buffers[$client_channel])) {
+                        $this->channel_buffers[$client_channel] = array();
+                    }
+                    $this->channel_buffers[$client_channel][] = $data;
+                    break;
+                case NET_SSH2_MSG_CHANNEL_EXTENDED_DATA:
+                    if ($client_channel == NET_SSH2_CHANNEL_EXEC) {
+                        $this->_send_channel_packet($client_channel, chr(0));
+                    }
+                    // currently, there's only one possible value for $data_type_code: NET_SSH2_EXTENDED_DATA_STDERR
+                    extract(unpack('Ndata_type_code/Nlength', $this->_string_shift($response, 8)));
+                    $data = $this->_string_shift($response, $length);
+                    if ($client_channel == $channel) {
+                        return $data;
+                    }
+                    if (!isset($this->channel_buffers[$client_channel])) {
+                        $this->channel_buffers[$client_channel] = array();
+                    }
+                    $this->channel_buffers[$client_channel][] = $data;
+                    break;
+                case NET_SSH2_MSG_CHANNEL_REQUEST:
+                    extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                    $value = $this->_string_shift($response, $length);
+                    switch ($value) {
+                        case 'exit-signal':
+                            $this->_string_shift($response, 1);
+                            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                            $this->errors[] = 'SSH_MSG_CHANNEL_REQUEST (exit-signal): ' . $this->_string_shift($response, $length);
+                            $this->_string_shift($response, 1);
+                            extract(unpack('Nlength', $this->_string_shift($response, 4)));
+                            if ($length) {
+                                $this->errors[count($this->errors)].= "\r\n" . $this->_string_shift($response, $length);
+                            }
+                        //case 'exit-status':
+                        default:
+                            // "Some systems may not implement signals, in which case they SHOULD ignore this message."
+                            //  -- http://tools.ietf.org/html/rfc4254#section-6.9
+                            break;
+                    }
+                    break;
+                case NET_SSH2_MSG_CHANNEL_CLOSE:
+                    $this->_send_binary_packet(pack('CN', NET_SSH2_MSG_CHANNEL_CLOSE, $this->server_channels[$channel]));
+                    return true;
+                case NET_SSH2_MSG_CHANNEL_EOF:
+                    break;
+                default:
+                    user_error('Error reading channel data', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
+            }
+        }
+    }
+
+    /**
+     * Sends Binary Packets
+     *
+     * See '6. Binary Packet Protocol' of rfc4253 for more info.
+     *
+     * @param String $data
+     * @see Net_SSH2::_get_binary_packet()
+     * @return Boolean
+     * @access private
+     */
+    function _send_binary_packet($data)
+    {
+        if (feof($this->fsock)) {
+            user_error('Connection closed prematurely', E_USER_NOTICE);
+            return false;
+        }
+
+        //if ($this->compress) {
+        //    // the -4 removes the checksum:
+        //    // http://php.net/function.gzcompress#57710
+        //    $data = substr(gzcompress($data), 0, -4);
+        //}
+
+        // 4 (packet length) + 1 (padding length) + 4 (minimal padding amount) == 9
+        $packet_length = strlen($data) + 9;
+        // round up to the nearest $this->encrypt_block_size
+        $packet_length+= (($this->encrypt_block_size - 1) * $packet_length) % $this->encrypt_block_size;
+        // subtracting strlen($data) is obvious - subtracting 5 is necessary because of packet_length and padding_length
+        $padding_length = $packet_length - strlen($data) - 5;
+
+        $padding = '';
+        for ($i = 0; $i < $padding_length; $i++) {
+            $padding.= chr(crypt_random(0, 255));
+        }
+
+        // we subtract 4 from packet_length because the packet_length field isn't supposed to include itself
+        $packet = pack('NCa*', $packet_length - 4, $padding_length, $data . $padding);
+
+        $hmac = $this->hmac_create !== false ? $this->hmac_create->hash(pack('Na*', $this->send_seq_no, $packet)) : '';
+        $this->send_seq_no++;
+
+        if ($this->encrypt !== false) {
+            $packet = $this->encrypt->encrypt($packet);
+        }
+
+        $packet.= $hmac;
+
+        $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
+        $result = strlen($packet) == fputs($this->fsock, $packet);
+        $stop = strtok(microtime(), ' ') + strtok('');
+
+        if (defined('NET_SSH2_LOGGING')) {
+            $temp = isset($this->message_numbers[ord($data[0])]) ? $this->message_numbers[ord($data[0])] : 'UNKNOWN';
+            $this->message_number_log[] = '-> ' . $temp .
+                                          ' (' . round($stop - $start, 4) . 's)';
+            if (NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX) {
+                $this->message_log[] = substr($data, 1);
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Sends channel data
+     *
+     * Spans multiple SSH_MSG_CHANNEL_DATAs if appropriate
+     *
+     * @param Integer $client_channel
+     * @param String $data
+     * @return Boolean
+     * @access private
+     */
+    function _send_channel_packet($client_channel, $data)
+    {
+        while (strlen($data) > $this->packet_size_client_to_server[$client_channel]) {
+            // resize the window, if appropriate
+            $this->window_size_client_to_server[$client_channel]-= $this->packet_size_client_to_server[$client_channel];
+            if ($this->window_size_client_to_server[$client_channel] < 0) {
+                $packet = pack('CNN', NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST, $this->server_channels[$client_channel], $this->window_size);
+                if (!$this->_send_binary_packet($packet)) {
+                    return false;
+                }
+                $this->window_size_client_to_server[$client_channel]+= $this->window_size;
+            }
+
+            $packet = pack('CN2a*',
+                NET_SSH2_MSG_CHANNEL_DATA,
+                $this->server_channels[$client_channel],
+                $this->packet_size_client_to_server[$client_channel],
+                $this->_string_shift($data, $this->packet_size_client_to_server[$client_channel])
+            );
+
+            if (!$this->_send_binary_packet($packet)) {
+                return false;
+            }
+        }
+
+        // resize the window, if appropriate
+        $this->window_size_client_to_server[$client_channel]-= strlen($data);
+        if ($this->window_size_client_to_server[$client_channel] < 0) {
+            $packet = pack('CNN', NET_SSH2_MSG_CHANNEL_WINDOW_ADJUST, $this->server_channels[$client_channel], $this->window_size);
+            if (!$this->_send_binary_packet($packet)) {
+                return false;
+            }
+            $this->window_size_client_to_server[$client_channel]+= $this->window_size;
+        }
+
+        return $this->_send_binary_packet(pack('CN2a*',
+            NET_SSH2_MSG_CHANNEL_DATA,
+            $this->server_channels[$client_channel],
+            strlen($data),
+            $data));
+    }
+
+    /**
+     * Disconnect
+     *
+     * @param Integer $reason
+     * @return Boolean
+     * @access private
+     */
+    function _disconnect($reason)
+    {
+        if ($this->bitmap) {
+            $data = pack('CNNa*Na*', NET_SSH2_MSG_DISCONNECT, $reason, 0, '', 0, '');
+            $this->_send_binary_packet($data);
+            $this->bitmap = 0;
+            fclose($this->fsock);
+            return false;
+        }
+    }
+
+    /**
+     * String Shift
+     *
+     * Inspired by array_shift
+     *
+     * @param String $string
+     * @param optional Integer $index
+     * @return String
+     * @access private
+     */
+    function _string_shift(&$string, $index = 1)
+    {
+        $substr = substr($string, 0, $index);
+        $string = substr($string, $index);
+        return $substr;
+    }
+
+    /**
+     * Define Array
+     *
+     * Takes any number of arrays whose indices are integers and whose values are strings and defines a bunch of
+     * named constants from it, using the value as the name of the constant and the index as the value of the constant.
+     * If any of the constants that would be defined already exists, none of the constants will be defined.
+     *
+     * @param Array $array
+     * @access private
+     */
+    function _define_array()
+    {
+        $args = func_get_args();
+        foreach ($args as $arg) {
+            foreach ($arg as $key=>$value) {
+                if (!defined($value)) {
+                    define($value, $key);
+                } else {
+                    break 2;
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns a log of the packets that have been sent and received.
+     *
+     * Returns a string if NET_SSH2_LOGGING == NET_SSH2_LOG_COMPLEX, an array if NET_SSH2_LOGGING == NET_SSH2_LOG_SIMPLE and false if !defined('NET_SSH2_LOGGING')
+     *
+     * @access public
+     * @return String or Array
+     */
+    function getLog()
+    {
+        if (!defined('NET_SSH2_LOGGING')) {
+            return false;
+        }
+
+        switch (NET_SSH2_LOGGING) {
+            case NET_SSH2_LOG_SIMPLE:
+                return $this->message_number_log;
+                break;
+            case NET_SSH2_LOG_COMPLEX:
+                return $this->_format_log($this->message_log, $this->message_number_log);
+                break;
+            default:
+                return false;
+        }
+    }
+
+    /**
+     * Formats a log for printing
+     *
+     * @param Array $message_log
+     * @param Array $message_number_log
+     * @access private
+     * @return String
+     */
+    function _format_log($message_log, $message_number_log)
+    {
+        static $boundary = ':', $long_width = 65, $short_width = 16;
+
+        $output = '';
+        for ($i = 0; $i < count($message_log); $i++) {
+            $output.= $message_number_log[$i] . "\r\n";
+            $current_log = $message_log[$i];
+            $j = 0;
+            do {
+                if (!empty($current_log)) {
+                    $output.= str_pad(dechex($j), 7, '0', STR_PAD_LEFT) . '0  ';
+                }
+                $fragment = $this->_string_shift($current_log, $short_width);
+                $hex = substr(
+                           preg_replace(
+                               '#(.)#es',
+                               '"' . $boundary . '" . str_pad(dechex(ord(substr("\\1", -1))), 2, "0", STR_PAD_LEFT)',
+                               $fragment),
+                           strlen($boundary)
+                       );
+                // replace non ASCII printable characters with dots
+                // http://en.wikipedia.org/wiki/ASCII#ASCII_printable_characters
+                // also replace < with a . since < messes up the output on web browsers
+                $raw = preg_replace('#[^\x20-\x7E]|<#', '.', $fragment);
+                $output.= str_pad($hex, $long_width - $short_width, ' ') . $raw . "\r\n";
+                $j++;
+            } while (!empty($current_log));
+            $output.= "\r\n";
+        }
+
+        return $output;
+    }
+
+    /**
+     * Returns all errors
+     *
+     * @return String
+     * @access public
+     */
+    function getErrors()
+    {
+        return $this->errors;
+    }
+
+    /**
+     * Returns the last error
+     *
+     * @return String
+     * @access public
+     */
+    function getLastError()
+    {
+        return $this->errors[count($this->errors) - 1];
+    }
+
+    /**
+     * Return the server identification.
+     *
+     * @return String
+     * @access public
+     */
+    function getServerIdentification()
+    {
+        return $this->server_identifier;
+    }
+
+    /**
+     * Return a list of the key exchange algorithms the server supports.
+     *
+     * @return Array
+     * @access public
+     */
+    function getKexAlgorithms()
+    {
+        return $this->kex_algorithms;
+    }
+
+    /**
+     * Return a list of the host key (public key) algorithms the server supports.
+     *
+     * @return Array
+     * @access public
+     */
+    function getServerHostKeyAlgorithms()
+    {
+        return $this->server_host_key_algorithms;
+    }
+
+    /**
+     * Return a list of the (symmetric key) encryption algorithms the server supports, when receiving stuff from the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getEncryptionAlgorithmsClient2Server()
+    {
+        return $this->encryption_algorithms_client_to_server;
+    }
+
+    /**
+     * Return a list of the (symmetric key) encryption algorithms the server supports, when sending stuff to the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getEncryptionAlgorithmsServer2Client()
+    {
+        return $this->encryption_algorithms_server_to_client;
+    }
+
+    /**
+     * Return a list of the MAC algorithms the server supports, when receiving stuff from the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getMACAlgorithmsClient2Server()
+    {
+        return $this->mac_algorithms_client_to_server;
+    }
+
+    /**
+     * Return a list of the MAC algorithms the server supports, when sending stuff to the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getMACAlgorithmsServer2Client()
+    {
+        return $this->mac_algorithms_server_to_client;
+    }
+
+    /**
+     * Return a list of the compression algorithms the server supports, when receiving stuff from the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getCompressionAlgorithmsClient2Server()
+    {
+        return $this->compression_algorithms_client_to_server;
+    }
+
+    /**
+     * Return a list of the compression algorithms the server supports, when sending stuff to the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getCompressionAlgorithmsServer2Client()
+    {
+        return $this->compression_algorithms_server_to_client;
+    }
+
+    /**
+     * Return a list of the languages the server supports, when sending stuff to the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getLanguagesServer2Client()
+    {
+        return $this->languages_server_to_client;
+    }
+
+    /**
+     * Return a list of the languages the server supports, when receiving stuff from the client.
+     *
+     * @return Array
+     * @access public
+     */
+    function getLanguagesClient2Server()
+    {
+        return $this->languages_client_to_server;
+    }
+
+    /**
+     * Returns the server public host key.
+     *
+     * Caching this the first time you connect to a server and checking the result on subsequent connections
+     * is recommended.  Returns false if the server signature is not signed correctly with the public host key.
+     *
+     * @return Mixed
+     * @access public
+     */
+    function getServerPublicHostKey()
+    {
+        $signature = $this->signature;
+        $server_public_host_key = $this->server_public_host_key;
+
+        extract(unpack('Nlength', $this->_string_shift($server_public_host_key, 4)));
+        $this->_string_shift($server_public_host_key, $length);
+
+        switch ($this->signature_format) {
+            case 'ssh-dss':
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $p = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $q = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $g = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $y = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+
+                /* The value for 'dss_signature_blob' is encoded as a string containing
+                   r, followed by s (which are 160-bit integers, without lengths or
+                   padding, unsigned, and in network byte order). */
+                $temp = unpack('Nlength', $this->_string_shift($signature, 4));
+                if ($temp['length'] != 40) {
+                    user_error('Invalid signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+                }
+
+                $r = new Math_BigInteger($this->_string_shift($signature, 20), 256);
+                $s = new Math_BigInteger($this->_string_shift($signature, 20), 256);
+
+                if ($r->compare($q) >= 0 || $s->compare($q) >= 0) {
+                    user_error('Invalid signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+                }
+
+                $w = $s->modInverse($q);
+
+                $u1 = $w->multiply(new Math_BigInteger(sha1($this->session_id), 16));
+                list(, $u1) = $u1->divide($q);
+
+                $u2 = $w->multiply($r);
+                list(, $u2) = $u2->divide($q);
+
+                $g = $g->modPow($u1, $p);
+                $y = $y->modPow($u2, $p);
+
+                $v = $g->multiply($y);
+                list(, $v) = $v->divide($p);
+                list(, $v) = $v->divide($q);
+
+                if (!$v->equals($r)) {
+                    user_error('Bad server signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
+                }
+
+                break;
+            case 'ssh-rsa':
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $e = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+
+                $temp = unpack('Nlength', $this->_string_shift($server_public_host_key, 4));
+                $n = new Math_BigInteger($this->_string_shift($server_public_host_key, $temp['length']), -256);
+                $nLength = $temp['length'];
+
+                /*
+                $temp = unpack('Nlength', $this->_string_shift($signature, 4));
+                $signature = $this->_string_shift($signature, $temp['length']);
+
+                if (!class_exists('Crypt_RSA')) {
+                    require_once('Crypt/RSA.php');
+                }
+
+                $rsa = new Crypt_RSA();
+                $rsa->setSignatureMode(CRYPT_RSA_SIGNATURE_PKCS1);
+                $rsa->loadKey(array('e' => $e, 'n' => $n), CRYPT_RSA_PUBLIC_FORMAT_RAW);
+                if (!$rsa->verify($this->session_id, $signature)) {
+                    user_error('Bad server signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
+                }
+                */
+
+                $temp = unpack('Nlength', $this->_string_shift($signature, 4));
+                $s = new Math_BigInteger($this->_string_shift($signature, $temp['length']), 256);
+
+                // validate an RSA signature per "8.2 RSASSA-PKCS1-v1_5", "5.2.2 RSAVP1", and "9.1 EMSA-PSS" in the
+                // following URL:
+                // ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1.pdf
+
+                // also, see SSHRSA.c (rsa2_verifysig) in PuTTy's source.
+
+                if ($s->compare(new Math_BigInteger()) < 0 || $s->compare($n->subtract(new Math_BigInteger(1))) > 0) {
+                    user_error('Invalid signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_KEY_EXCHANGE_FAILED);
+                }
+
+                $s = $s->modPow($e, $n);
+                $s = $s->toBytes();
+
+                $h = pack('N4H*', 0x00302130, 0x0906052B, 0x0E03021A, 0x05000414, sha1($this->session_id));
+                $h = chr(0x01) . str_repeat(chr(0xFF), $nLength - 3 - strlen($h)) . $h;
+
+                if ($s != $h) {
+                    user_error('Bad server signature', E_USER_NOTICE);
+                    return $this->_disconnect(NET_SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE);
+                }
+        }
+
+        return $this->server_public_host_key;
+    }
+}
+\ No newline at end of file
author	Mike Macgirvin <mike@macgirvin.com>	2010-10-07 02:53:31 -0700
committer	Mike Macgirvin <mike@macgirvin.com>	2010-10-07 02:53:31 -0700
commit	4daed0a009645377596fcf495a64edb32ee2245e (patch)
tree	072a695c28c96f33fcaad581c96f224da8e49efd /phpsec/Net
parent	9c10ada9060c9745f49652469e172be8152f6cad (diff)
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