463 lines
14 KiB
PHP
463 lines
14 KiB
PHP
<?php
|
|
|
|
/**
|
|
* Pure-PHP ssh-agent client.
|
|
*
|
|
* PHP versions 4 and 5
|
|
*
|
|
* Here are some examples of how to use this library:
|
|
* <code>
|
|
* <?php
|
|
* include 'System/SSH/Agent.php';
|
|
* include 'Net/SSH2.php';
|
|
*
|
|
* $agent = new System_SSH_Agent();
|
|
*
|
|
* $ssh = new Net_SSH2('www.domain.tld');
|
|
* if (!$ssh->login('username', $agent)) {
|
|
* exit('Login Failed');
|
|
* }
|
|
*
|
|
* echo $ssh->exec('pwd');
|
|
* echo $ssh->exec('ls -la');
|
|
* ?>
|
|
* </code>
|
|
*
|
|
* LICENSE: Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*
|
|
* @category System
|
|
* @package System_SSH_Agent
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @copyright 2014 Jim Wigginton
|
|
* @license http://www.opensource.org/licenses/mit-license.html MIT License
|
|
* @link http://phpseclib.sourceforge.net
|
|
* @internal See http://api.libssh.org/rfc/PROTOCOL.agent
|
|
*/
|
|
|
|
/**#@+
|
|
* Message numbers
|
|
*
|
|
* @access private
|
|
*/
|
|
// to request SSH1 keys you have to use SSH_AGENTC_REQUEST_RSA_IDENTITIES (1)
|
|
define('SYSTEM_SSH_AGENTC_REQUEST_IDENTITIES', 11);
|
|
// this is the SSH2 response; the SSH1 response is SSH_AGENT_RSA_IDENTITIES_ANSWER (2).
|
|
define('SYSTEM_SSH_AGENT_IDENTITIES_ANSWER', 12);
|
|
define('SYSTEM_SSH_AGENT_FAILURE', 5);
|
|
// the SSH1 request is SSH_AGENTC_RSA_CHALLENGE (3)
|
|
define('SYSTEM_SSH_AGENTC_SIGN_REQUEST', 13);
|
|
// the SSH1 response is SSH_AGENT_RSA_RESPONSE (4)
|
|
define('SYSTEM_SSH_AGENT_SIGN_RESPONSE', 14);
|
|
|
|
|
|
/**@+
|
|
* Agent forwarding status
|
|
*
|
|
* @access private
|
|
*/
|
|
// no forwarding requested and not active
|
|
define('SYSTEM_SSH_AGENT_FORWARD_NONE', 0);
|
|
// request agent forwarding when opportune
|
|
define('SYSTEM_SSH_AGENT_FORWARD_REQUEST', 1);
|
|
// forwarding has been request and is active
|
|
define('SYSTEM_SSH_AGENT_FORWARD_ACTIVE', 2);
|
|
|
|
/**#@-*/
|
|
|
|
/**
|
|
* Pure-PHP ssh-agent client identity object
|
|
*
|
|
* Instantiation should only be performed by System_SSH_Agent class.
|
|
* This could be thought of as implementing an interface that Crypt_RSA
|
|
* implements. ie. maybe a Net_SSH_Auth_PublicKey interface or something.
|
|
* The methods in this interface would be getPublicKey, setSignatureMode
|
|
* and sign since those are the methods phpseclib looks for to perform
|
|
* public key authentication.
|
|
*
|
|
* @package System_SSH_Agent
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @access internal
|
|
*/
|
|
class System_SSH_Agent_Identity
|
|
{
|
|
/**
|
|
* Key Object
|
|
*
|
|
* @var Crypt_RSA
|
|
* @access private
|
|
* @see self::getPublicKey()
|
|
*/
|
|
var $key;
|
|
|
|
/**
|
|
* Key Blob
|
|
*
|
|
* @var string
|
|
* @access private
|
|
* @see self::sign()
|
|
*/
|
|
var $key_blob;
|
|
|
|
/**
|
|
* Socket Resource
|
|
*
|
|
* @var resource
|
|
* @access private
|
|
* @see self::sign()
|
|
*/
|
|
var $fsock;
|
|
|
|
/**
|
|
* Default Constructor.
|
|
*
|
|
* @param resource $fsock
|
|
* @return System_SSH_Agent_Identity
|
|
* @access private
|
|
*/
|
|
function System_SSH_Agent_Identity($fsock)
|
|
{
|
|
$this->fsock = $fsock;
|
|
}
|
|
|
|
/**
|
|
* Set Public Key
|
|
*
|
|
* Called by System_SSH_Agent::requestIdentities()
|
|
*
|
|
* @param Crypt_RSA $key
|
|
* @access private
|
|
*/
|
|
function setPublicKey($key)
|
|
{
|
|
$this->key = $key;
|
|
$this->key->setPublicKey();
|
|
}
|
|
|
|
/**
|
|
* Set Public Key
|
|
*
|
|
* Called by System_SSH_Agent::requestIdentities(). The key blob could be extracted from $this->key
|
|
* but this saves a small amount of computation.
|
|
*
|
|
* @param string $key_blob
|
|
* @access private
|
|
*/
|
|
function setPublicKeyBlob($key_blob)
|
|
{
|
|
$this->key_blob = $key_blob;
|
|
}
|
|
|
|
/**
|
|
* Get Public Key
|
|
*
|
|
* Wrapper for $this->key->getPublicKey()
|
|
*
|
|
* @param int $format optional
|
|
* @return mixed
|
|
* @access public
|
|
*/
|
|
function getPublicKey($format = null)
|
|
{
|
|
return !isset($format) ? $this->key->getPublicKey() : $this->key->getPublicKey($format);
|
|
}
|
|
|
|
/**
|
|
* Set Signature Mode
|
|
*
|
|
* Doesn't do anything as ssh-agent doesn't let you pick and choose the signature mode. ie.
|
|
* ssh-agent's only supported mode is CRYPT_RSA_SIGNATURE_PKCS1
|
|
*
|
|
* @param int $mode
|
|
* @access public
|
|
*/
|
|
function setSignatureMode($mode)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Create a signature
|
|
*
|
|
* See "2.6.2 Protocol 2 private key signature request"
|
|
*
|
|
* @param string $message
|
|
* @return string
|
|
* @access public
|
|
*/
|
|
function sign($message)
|
|
{
|
|
// the last parameter (currently 0) is for flags and ssh-agent only defines one flag (for ssh-dss): SSH_AGENT_OLD_SIGNATURE
|
|
$packet = pack('CNa*Na*N', SYSTEM_SSH_AGENTC_SIGN_REQUEST, strlen($this->key_blob), $this->key_blob, strlen($message), $message, 0);
|
|
$packet = pack('Na*', strlen($packet), $packet);
|
|
if (strlen($packet) != fputs($this->fsock, $packet)) {
|
|
user_error('Connection closed during signing');
|
|
}
|
|
|
|
$length = current(unpack('N', fread($this->fsock, 4)));
|
|
$type = ord(fread($this->fsock, 1));
|
|
if ($type != SYSTEM_SSH_AGENT_SIGN_RESPONSE) {
|
|
user_error('Unable to retreive signature');
|
|
}
|
|
|
|
$signature_blob = fread($this->fsock, $length - 1);
|
|
// the only other signature format defined - ssh-dss - is the same length as ssh-rsa
|
|
// the + 12 is for the other various SSH added length fields
|
|
return substr($signature_blob, strlen('ssh-rsa') + 12);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Pure-PHP ssh-agent client identity factory
|
|
*
|
|
* requestIdentities() method pumps out System_SSH_Agent_Identity objects
|
|
*
|
|
* @package System_SSH_Agent
|
|
* @author Jim Wigginton <terrafrost@php.net>
|
|
* @access internal
|
|
*/
|
|
class System_SSH_Agent
|
|
{
|
|
/**
|
|
* Socket Resource
|
|
*
|
|
* @var resource
|
|
* @access private
|
|
*/
|
|
var $fsock;
|
|
|
|
/**
|
|
* Agent forwarding status
|
|
*
|
|
* @access private
|
|
*/
|
|
var $forward_status = SYSTEM_SSH_AGENT_FORWARD_NONE;
|
|
|
|
/**
|
|
* Buffer for accumulating forwarded authentication
|
|
* agent data arriving on SSH data channel destined
|
|
* for agent unix socket
|
|
*
|
|
* @access private
|
|
*/
|
|
var $socket_buffer = '';
|
|
|
|
/**
|
|
* Tracking the number of bytes we are expecting
|
|
* to arrive for the agent socket on the SSH data
|
|
* channel
|
|
*/
|
|
var $expected_bytes = 0;
|
|
|
|
/**
|
|
* Default Constructor
|
|
*
|
|
* @return System_SSH_Agent
|
|
* @access public
|
|
*/
|
|
function System_SSH_Agent()
|
|
{
|
|
switch (true) {
|
|
case isset($_SERVER['SSH_AUTH_SOCK']):
|
|
$address = $_SERVER['SSH_AUTH_SOCK'];
|
|
break;
|
|
case isset($_ENV['SSH_AUTH_SOCK']):
|
|
$address = $_ENV['SSH_AUTH_SOCK'];
|
|
break;
|
|
default:
|
|
user_error('SSH_AUTH_SOCK not found');
|
|
return false;
|
|
}
|
|
|
|
$this->fsock = fsockopen('unix://' . $address, 0, $errno, $errstr);
|
|
if (!$this->fsock) {
|
|
user_error("Unable to connect to ssh-agent (Error $errno: $errstr)");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Request Identities
|
|
*
|
|
* See "2.5.2 Requesting a list of protocol 2 keys"
|
|
* Returns an array containing zero or more System_SSH_Agent_Identity objects
|
|
*
|
|
* @return array
|
|
* @access public
|
|
*/
|
|
function requestIdentities()
|
|
{
|
|
if (!$this->fsock) {
|
|
return array();
|
|
}
|
|
|
|
$packet = pack('NC', 1, SYSTEM_SSH_AGENTC_REQUEST_IDENTITIES);
|
|
if (strlen($packet) != fputs($this->fsock, $packet)) {
|
|
user_error('Connection closed while requesting identities');
|
|
}
|
|
|
|
$length = current(unpack('N', fread($this->fsock, 4)));
|
|
$type = ord(fread($this->fsock, 1));
|
|
if ($type != SYSTEM_SSH_AGENT_IDENTITIES_ANSWER) {
|
|
user_error('Unable to request identities');
|
|
}
|
|
|
|
$identities = array();
|
|
$keyCount = current(unpack('N', fread($this->fsock, 4)));
|
|
for ($i = 0; $i < $keyCount; $i++) {
|
|
$length = current(unpack('N', fread($this->fsock, 4)));
|
|
$key_blob = fread($this->fsock, $length);
|
|
$length = current(unpack('N', fread($this->fsock, 4)));
|
|
if ($length) {
|
|
$key_comment = fread($this->fsock, $length);
|
|
}
|
|
$length = current(unpack('N', substr($key_blob, 0, 4)));
|
|
$key_type = substr($key_blob, 4, $length);
|
|
switch ($key_type) {
|
|
case 'ssh-rsa':
|
|
if (!class_exists('Crypt_RSA')) {
|
|
include_once 'Crypt/RSA.php';
|
|
}
|
|
$key = new Crypt_RSA();
|
|
$key->loadKey('ssh-rsa ' . base64_encode($key_blob) . ' ' . $key_comment);
|
|
break;
|
|
case 'ssh-dss':
|
|
// not currently supported
|
|
break;
|
|
}
|
|
// resources are passed by reference by default
|
|
if (isset($key)) {
|
|
$identity = new System_SSH_Agent_Identity($this->fsock);
|
|
$identity->setPublicKey($key);
|
|
$identity->setPublicKeyBlob($key_blob);
|
|
$identities[] = $identity;
|
|
unset($key);
|
|
}
|
|
}
|
|
|
|
return $identities;
|
|
}
|
|
|
|
/**
|
|
* Signal that agent forwarding should
|
|
* be requested when a channel is opened
|
|
*
|
|
* @param Net_SSH2 $ssh
|
|
* @return bool
|
|
* @access public
|
|
*/
|
|
function startSSHForwarding($ssh)
|
|
{
|
|
if ($this->forward_status == SYSTEM_SSH_AGENT_FORWARD_NONE) {
|
|
$this->forward_status = SYSTEM_SSH_AGENT_FORWARD_REQUEST;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Request agent forwarding of remote server
|
|
*
|
|
* @param Net_SSH2 $ssh
|
|
* @return bool
|
|
* @access private
|
|
*/
|
|
function _request_forwarding($ssh)
|
|
{
|
|
$request_channel = $ssh->_get_open_channel();
|
|
if ($request_channel === false) {
|
|
return false;
|
|
}
|
|
|
|
$packet = pack(
|
|
'CNNa*C',
|
|
NET_SSH2_MSG_CHANNEL_REQUEST,
|
|
$ssh->server_channels[$request_channel],
|
|
strlen('auth-agent-req@openssh.com'),
|
|
'auth-agent-req@openssh.com',
|
|
1
|
|
);
|
|
|
|
$ssh->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_REQUEST;
|
|
|
|
if (!$ssh->_send_binary_packet($packet)) {
|
|
return false;
|
|
}
|
|
|
|
$response = $ssh->_get_channel_packet($request_channel);
|
|
if ($response === false) {
|
|
return false;
|
|
}
|
|
|
|
$ssh->channel_status[$request_channel] = NET_SSH2_MSG_CHANNEL_OPEN;
|
|
$this->forward_status = SYSTEM_SSH_AGENT_FORWARD_ACTIVE;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* On successful channel open
|
|
*
|
|
* This method is called upon successful channel
|
|
* open to give the SSH Agent an opportunity
|
|
* to take further action. i.e. request agent forwarding
|
|
*
|
|
* @param Net_SSH2 $ssh
|
|
* @access private
|
|
*/
|
|
function _on_channel_open($ssh)
|
|
{
|
|
if ($this->forward_status == SYSTEM_SSH_AGENT_FORWARD_REQUEST) {
|
|
$this->_request_forwarding($ssh);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Forward data to SSH Agent and return data reply
|
|
*
|
|
* @param string $data
|
|
* @return data from SSH Agent
|
|
* @access private
|
|
*/
|
|
function _forward_data($data)
|
|
{
|
|
if ($this->expected_bytes > 0) {
|
|
$this->socket_buffer.= $data;
|
|
$this->expected_bytes -= strlen($data);
|
|
} else {
|
|
$agent_data_bytes = current(unpack('N', $data));
|
|
$current_data_bytes = strlen($data);
|
|
$this->socket_buffer = $data;
|
|
if ($current_data_bytes != $agent_data_bytes + 4) {
|
|
$this->expected_bytes = ($agent_data_bytes + 4) - $current_data_bytes;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (strlen($this->socket_buffer) != fwrite($this->fsock, $this->socket_buffer)) {
|
|
user_error('Connection closed attempting to forward data to SSH agent');
|
|
}
|
|
|
|
$this->socket_buffer = '';
|
|
$this->expected_bytes = 0;
|
|
|
|
$agent_reply_bytes = current(unpack('N', fread($this->fsock, 4)));
|
|
|
|
$agent_reply_data = fread($this->fsock, $agent_reply_bytes);
|
|
$agent_reply_data = current(unpack('a*', $agent_reply_data));
|
|
|
|
return pack('Na*', $agent_reply_bytes, $agent_reply_data);
|
|
}
|
|
}
|