Merge branch 'openssl-support' of https://github.com/terrafrost/phpseclib into openssl-support

phpseclib/Net/SSH2.php

@@ -99,6 +99,7 @@ define('NET_SSH2_MASK_WINDOW_ADJUST', 0x00000020);
 define('NET_SSH2_CHANNEL_EXEC',      0); // PuTTy uses 0x100
 define('NET_SSH2_CHANNEL_SHELL',     1);
 define('NET_SSH2_CHANNEL_SUBSYSTEM', 2);
+define('NET_SSH2_CHANNEL_AGENT_FORWARD', 3);
 /**#@-*/
 
 /**#@+
@@ -803,21 +804,6 @@ class Net_SSH2
      */
     var $port;
 
-    /**
-     * Timeout for initial connection
-     *
-     * Set by the constructor call. Calling setTimeout() is optional. If it's not called functions like
-     * exec() won't timeout unless some PHP setting forces it too. The timeout specified in the constructor,
-     * however, is non-optional. There will be a timeout, whether or not you set it. If you don't it'll be
-     * 10 seconds. It is used by fsockopen() and the initial stream_select in that function.
-     *
-     * @see Net_SSH2::Net_SSH2()
-     * @see Net_SSH2::_connect()
-     * @var Integer
-     * @access private
-     */
-    var $connectionTimeout;
-
     /**
      * Number of columns for terminal window size
      *
@@ -850,6 +836,14 @@ class Net_SSH2
      */
     var $crypto_engine = false;
 
+    /**
+     * A System_SSH_Agent for use in the SSH2 Agent Forwarding scenario
+     *
+     * @var System_SSH_Agent
+     * @access private
+     */
+    var $agent;
+
     /**
      * Default Constructor.
      *
@@ -953,7 +947,7 @@ class Net_SSH2
 
         $this->host = $host;
         $this->port = $port;
-        $this->connectionTimeout = $timeout;
+        $this->timeout = $timeout;
     }
 
     /**
@@ -984,36 +978,24 @@ class Net_SSH2
 
         $this->bitmap |= NET_SSH2_MASK_CONSTRUCTOR;
 
-        $timeout = $this->connectionTimeout;
+        $this->curTimeout = $this->timeout;
+
         $host = $this->host . ':' . $this->port;
 
         $this->last_packet = strtok(microtime(), ' ') + strtok(''); // == microtime(true) in PHP5
 
         $start = strtok(microtime(), ' ') + strtok(''); // http://php.net/microtime#61838
-        $this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $timeout);
+        $this->fsock = @fsockopen($this->host, $this->port, $errno, $errstr, $this->curTimeout);
         if (!$this->fsock) {
             user_error(rtrim("Cannot connect to $host. Error $errno. $errstr"));
             return false;
         }
         $elapsed = strtok(microtime(), ' ') + strtok('') - $start;
 
-        $timeout-= $elapsed;
+        $this->curTimeout-= $elapsed;
 
-        if ($timeout <= 0) {
+        if ($this->curTimeout <= 0) {
-            user_error("Cannot connect to $host. Timeout error");
+            $this->is_timeout = true;
-            return false;
-        }
-
-        $read = array($this->fsock);
-        $write = $except = null;
-
-        $sec = floor($timeout);
-        $usec = 1000000 * ($timeout - $sec);
-
-        // on windows this returns a "Warning: Invalid CRT parameters detected" error
-        // the !count() is done as a workaround for <https://bugs.php.net/42682>
-        if (!@stream_select($read, $write, $except, $sec, $usec) && !count($read)) {
-            user_error("Cannot connect to $host. Banner timeout");
             return false;
         }
 
@@ -1031,6 +1013,27 @@ class Net_SSH2
                 $extra.= $temp;
                 $temp = '';
             }
+
+            if ($this->curTimeout) {
+                if ($this->curTimeout < 0) {
+                    $this->is_timeout = true;
+                    return false;
+                }
+                $read = array($this->fsock);
+                $write = $except = null;
+                $start = strtok(microtime(), ' ') + strtok('');
+                $sec = floor($this->curTimeout);
+                $usec = 1000000 * ($this->curTimeout - $sec);
+                // on windows this returns a "Warning: Invalid CRT parameters detected" error
+                // the !count() is done as a workaround for <https://bugs.php.net/42682>
+                if (!@stream_select($read, $write, $except, $sec, $usec) && !count($read)) {
+                    $this->is_timeout = true;
+                    return false;
+                }
+                $elapsed = strtok(microtime(), ' ') + strtok('') - $start;
+                $this->curTimeout-= $elapsed;
+            }
+
             $temp.= fgets($this->fsock, 255);
         }
 
@@ -2178,6 +2181,7 @@ class Net_SSH2
      */
     function _ssh_agent_login($username, $agent)
     {
+        $this->agent = $agent;
         $keys = $agent->requestIdentities();
         foreach ($keys as $key) {
             if ($this->_privatekey_login($username, $key)) {
@@ -2357,6 +2361,7 @@ class Net_SSH2
             if (!$this->_send_binary_packet($packet)) {
                 return false;
             }
+
             $response = $this->_get_binary_packet();
             if ($response === false) {
                 user_error('Connection closed by server');
@@ -2387,6 +2392,7 @@ class Net_SSH2
         // "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;
         }
@@ -2523,6 +2529,24 @@ class Net_SSH2
         }
     }
 
+    /**
+     * Return an available open channel
+     *
+     * @return Integer
+     * @access public
+     */
+    function _get_open_channel()
+    {
+        $channel = NET_SSH2_CHANNEL_EXEC;
+        do {
+            if (isset($this->channel_status[$channel]) && $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_OPEN) {
+                return $channel;
+            }
+        } while ($channel++ < NET_SSH2_CHANNEL_SUBSYSTEM);
+
+        return false;
+    }
+
     /**
      * Returns the output of an interactive shell
      *
@@ -2881,18 +2905,41 @@ class Net_SSH2
                 case NET_SSH2_MSG_CHANNEL_OPEN: // see http://tools.ietf.org/html/rfc4254#section-5.1
                     $this->_string_shift($payload, 1);
                     extract(unpack('Nlength', $this->_string_shift($payload, 4)));
-                    $this->errors[] = 'SSH_MSG_CHANNEL_OPEN: ' . utf8_decode($this->_string_shift($payload, $length));
+                    $data = $this->_string_shift($payload, $length);
-
-                    $this->_string_shift($payload, 4); // skip over client channel
                     extract(unpack('Nserver_channel', $this->_string_shift($payload, 4)));
+                    switch($data) {
+                        case 'auth-agent':
+                        case 'auth-agent@openssh.com':
+                            if (isset($this->agent)) {
+                                  $new_channel = NET_SSH2_CHANNEL_AGENT_FORWARD;
 
+                                  extract(unpack('Nremote_window_size', $this->_string_shift($payload, 4)));
+                                  extract(unpack('Nremote_maximum_packet_size', $this->_string_shift($payload, 4)));
+
+                                  $this->packet_size_client_to_server[$new_channel] = $remote_window_size;
+                                  $this->window_size_server_to_client[$new_channel] = $remote_maximum_packet_size;
+                                  $this->window_size_client_to_server[$new_channel] = $this->window_size;
+
+                                  $packet_size = 0x4000;
+
+                                  $packet = pack('CN4',
+                                      NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, $server_channel, $new_channel, $packet_size, $packet_size);
+
+                                  $this->server_channels[$new_channel] = $server_channel;
+                                  $this->channel_status[$new_channel] = NET_SSH2_MSG_CHANNEL_OPEN_CONFIRMATION;
+                                  if (!$this->_send_binary_packet($packet)) {
+                                      return false;
+                                  }
+                            }
+                            break;
+                        default:
                             $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:
@@ -3029,8 +3076,16 @@ class Net_SSH2
                 return '';
             }
 
-            extract(unpack('Ctype/Nchannel', $this->_string_shift($response, 5)));
+            extract(unpack('Ctype', $this->_string_shift($response, 1)));
 
+            if ($type == NET_SSH2_MSG_CHANNEL_OPEN) {
+                extract(unpack('Nlength', $this->_string_shift($response, 4)));
+            } else {
+                extract(unpack('Nchannel', $this->_string_shift($response, 4)));
+            }
+
+            // will not be setup yet on incoming channel open request
+            if (isset($channel) && isset($this->channel_status[$channel]) && isset($this->window_size_server_to_client[$channel])) {
                 $this->window_size_server_to_client[$channel]-= strlen($response);
 
                 // resize the window, if appropriate
@@ -3052,7 +3107,9 @@ class Net_SSH2
                                 $this->window_size_client_to_server[$channel] = $window_size;
                                 $temp = unpack('Npacket_size_client_to_server', $this->_string_shift($response, 4));
                                 $this->packet_size_client_to_server[$channel] = $temp['packet_size_client_to_server'];
-                            return $client_channel == $channel ? true : $this->_get_channel_packet($client_channel, $skip_extended);
+                                $result = $client_channel == $channel ? true : $this->_get_channel_packet($client_channel, $skip_extended);
+                                $this->_on_channel_open();
+                                return $result;
                             //case NET_SSH2_MSG_CHANNEL_OPEN_FAILURE:
                             default:
                                 user_error('Unable to open channel');
@@ -3072,6 +3129,7 @@ class Net_SSH2
                     case NET_SSH2_MSG_CHANNEL_CLOSE:
                         return $type == NET_SSH2_MSG_CHANNEL_CLOSE ? true : $this->_get_channel_packet($client_channel, $skip_extended);
                 }
+            }
 
             // ie. $this->channel_status[$channel] == NET_SSH2_MSG_CHANNEL_DATA
 
@@ -3088,6 +3146,15 @@ class Net_SSH2
                     */
                     extract(unpack('Nlength', $this->_string_shift($response, 4)));
                     $data = $this->_string_shift($response, $length);
+
+                    if ($channel == NET_SSH2_CHANNEL_AGENT_FORWARD) {
+                        $agent_response = $this->agent->_forward_data($data);
+                        if (!is_bool($agent_response)) {
+                            $this->_send_channel_packet($channel, $agent_response);
+                        }
+                        break;
+                    }
+
                     if ($client_channel == $channel) {
                         return $data;
                     }
@@ -3524,6 +3591,22 @@ class Net_SSH2
         return $this->log_boundary . str_pad(dechex(ord($matches[0])), 2, '0', STR_PAD_LEFT);
     }
 
+    /**
+     * Helper function for agent->_on_channel_open()
+     *
+     * Used when channels are created to inform agent
+     * of said channel opening. Must be called after
+     * channel open confirmation received
+     *
+     * @access private
+     */
+    function _on_channel_open()
+    {
+        if (isset($this->agent)) {
+            $this->agent->_on_channel_open($this);
+        }
+    }
+
     /**
      * Returns all errors
      *

phpseclib/System/SSH/Agent.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * Pure-PHP ssh-agent client.
  *
@@ -63,6 +64,20 @@ define('SYSTEM_SSH_AGENT_FAILURE', 5);
 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);
+
 /**#@-*/
 
 /**
@@ -225,6 +240,29 @@ class System_SSH_Agent
      */
     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
      *
@@ -310,4 +348,107 @@ class System_SSH_Agent
 
         return $identities;
     }
+
+    /**
+     * Signal that agent forwarding should
+     * be requested when a channel is opened
+     *
+     * @param Net_SSH2 $ssh
+     * @return Boolean
+     * @access public
+     */
+    function startSSHForwarding($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 $ssh
+     * @return Boolean
+     * @access private
+     */
+    function _request_forwarding($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);
+    }
 }

tests/Functional/Net/SSH2AgentTest.php

@@ -27,5 +27,26 @@ class Functional_Net_SSH2AgentTest extends PhpseclibFunctionalTestCase
             $ssh->login($this->getEnv('SSH_USERNAME'), $agent),
             'SSH2 login using Agent failed.'
         );
+
+        return array('ssh' => $ssh, 'ssh-agent' => $agent);
+    }
+
+    /**
+     * @depends testAgentLogin
+     */
+    public function testAgentForward($args)
+    {
+        $ssh = $args['ssh'];
+        $agent = $args['ssh-agent'];
+
+        $hostname = $this->getEnv('SSH_HOSTNAME');
+        $username = $this->getEnv('SSH_USERNAME');
+
+        $this->assertEquals($username, trim($ssh->exec('whoami')));
+
+        $agent->startSSHForwarding($ssh);
+        $this->assertEquals($username, trim($ssh->exec("ssh " . $username . "@" . $hostname . ' \'whoami\'')));
+
+        return $args;
     }
 }

travis/setup-secure-shell.sh

@@ -28,4 +28,6 @@ ssh-add "$HOME/.ssh/id_rsa"
 # Allow the private key of the travis user to log in as phpseclib user
 sudo mkdir -p "/home/$USERNAME/.ssh/"
 sudo cp "$HOME/.ssh/id_rsa.pub" "/home/$USERNAME/.ssh/authorized_keys"
+sudo ssh-keyscan -t rsa localhost > "/tmp/known_hosts"
+sudo cp "/tmp/known_hosts" "/home/$USERNAME/.ssh/known_hosts"
 sudo chown "$USERNAME:$USERNAME" "/home/$USERNAME/.ssh/" -R