<?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);
}
}
?>
