php/external/Zend/Http/Client/Adapter/Proxy.php

<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Http
 * @subpackage Client_Adapter
 * @version    $Id: Proxy.php 8064 2008-02-16 10:58:39Z thomas $
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

require_once 'external/Zend/Uri/Http.php';
require_once 'external/Zend/Http/Client.php';
require_once 'external/Zend/Http/Client/Adapter/Socket.php';

/**
 * HTTP Proxy-supporting Zend_Http_Client adapter class, based on the default
 * socket based adapter.
 *
 * Should be used if proxy HTTP access is required. If no proxy is set, will
 * fall back to Zend_Http_Client_Adapter_Socket behavior. Just like the
 * default Socket adapter, this adapter does not require any special extensions
 * installed.
 *
 * @category   Zend
 * @package    Zend_Http
 * @subpackage Client_Adapter
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Http_Client_Adapter_Proxy extends Zend_Http_Client_Adapter_Socket {
  /**
   * Parameters array
   *
   * @var array
   */
  protected $config = array('ssltransport' => 'ssl', 'proxy_host' => '', 'proxy_port' => 8080, 
      'proxy_user' => '', 'proxy_pass' => '', 'proxy_auth' => Zend_Http_Client::AUTH_BASIC);
  
  /**
   * Whether HTTPS CONNECT was already negotiated with the proxy or not
   *
   * @var boolean
   */
  protected $negotiated = false;

  /**
   * Connect to the remote server
   *
   * Will try to connect to the proxy server. If no proxy was set, will
   * fall back to the target server (behave like regular Socket adapter)
   *
   * @param string  $host
   * @param int     $port
   * @param boolean $secure
   * @param int     $timeout
   */
  public function connect($host, $port = 80, $secure = false) {
    // If no proxy is set, fall back to Socket adapter
    if (! $this->config['proxy_host']) return parent::connect($host, $port, $secure);
    
    // Go through a proxy - the connection is actually to the proxy server
    $host = $this->config['proxy_host'];
    $port = $this->config['proxy_port'];
    
    // If we are connected to the wrong proxy, disconnect first
    if (($this->connected_to[0] != $host || $this->connected_to[1] != $port)) {
      if (is_resource($this->socket)) $this->close();
    }
    
    // Now, if we are not connected, connect
    if (! is_resource($this->socket) || ! $this->config['keepalive']) {
      $this->socket = @fsockopen($host, $port, $errno, $errstr, (int)$this->config['timeout']);
      if (! $this->socket) {
        $this->close();
        require_once 'external/Zend/Http/Client/Adapter/Exception.php';
        throw new Zend_Http_Client_Adapter_Exception('Unable to Connect to proxy server ' . $host . ':' . $port . '. Error #' . $errno . ': ' . $errstr);
      }
      
      // Set the stream timeout
      if (! stream_set_timeout($this->socket, (int)$this->config['timeout'])) {
        require_once 'external/Zend/Http/Client/Adapter/Exception.php';
        throw new Zend_Http_Client_Adapter_Exception('Unable to set the connection timeout');
      }
      
      // Update connected_to
      $this->connected_to = array($host, $port);
    }
  }

  /**
   * Send request to the proxy server
   *
   * @param string        $method
   * @param Zend_Uri_Http $uri
   * @param string        $http_ver
   * @param array         $headers
   * @param string        $body
   * @return string Request as string
   */
  public function write($method, $uri, $http_ver = '1.1', $headers = array(), $body = '') {
    // If no proxy is set, fall back to default Socket adapter
    if (! $this->config['proxy_host']) return parent::write($method, $uri, $http_ver, $headers, $body);
    
    // Make sure we're properly connected
    if (! $this->socket) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Trying to write but we are not connected");
    }
    
    $host = $this->config['proxy_host'];
    $port = $this->config['proxy_port'];
    
    if ($this->connected_to[0] != $host || $this->connected_to[1] != $port) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Trying to write but we are connected to the wrong proxy server");
    }
    
    // Add Proxy-Authorization header
    if ($this->config['proxy_user'] && ! isset($headers['proxy-authorization'])) $headers['proxy-authorization'] = Zend_Http_Client::encodeAuthHeader($this->config['proxy_user'], $this->config['proxy_pass'], $this->config['proxy_auth']);
    
    // if we are proxying HTTPS, preform CONNECT handshake with the proxy
    if ($uri->getScheme() == 'https' && (! $this->negotiated)) {
      $this->connectHandshake($uri->getHost(), $uri->getPort(), $http_ver, $headers);
      $this->negotiated = true;
    }
    
    // Save request method for later
    $this->method = $method;
    
    // Build request headers
    $request = "{$method} {$uri->__toString()} HTTP/{$http_ver}\r\n";
    
    // Add all headers to the request string
    foreach ($headers as $k => $v) {
      if (is_string($k)) $v = "$k: $v";
      $request .= "$v\r\n";
    }
    
    // Add the request body
    $request .= "\r\n" . $body;
    
    // Send the request
    if (! @fwrite($this->socket, $request)) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Error writing request to proxy server");
    }
    
    return $request;
  }

  /**
   * Preform handshaking with HTTPS proxy using CONNECT method
   *
   * @param string  $host
   * @param integer $port
   * @param string  $http_ver
   * @param array   $headers
   */
  protected function connectHandshake($host, $port = 443, $http_ver = '1.1', array &$headers = array()) {
    $request = "CONNECT $host:$port HTTP/$http_ver\r\n" . "Host: " . $this->config['proxy_host'] . "\r\n";
    
    // Add the user-agent header
    if (isset($this->config['useragent'])) {
      $request .= "User-agent: " . $this->config['useragent'] . "\r\n";
    }
    
    // If the proxy-authorization header is set, send it to proxy but remove
    // it from headers sent to target host
    if (isset($headers['proxy-authorization'])) {
      $request .= "Proxy-authorization: " . $headers['proxy-authorization'] . "\r\n";
      unset($headers['proxy-authorization']);
    }
    
    $request .= "\r\n";
    
    // Send the request
    if (! @fwrite($this->socket, $request)) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Error writing request to proxy server");
    }
    
    // Read response headers only
    $response = '';
    $gotStatus = false;
    while ($line = @fgets($this->socket)) {
      $gotStatus = $gotStatus || (strpos($line, 'HTTP') !== false);
      if ($gotStatus) {
        $response .= $line;
        if (! chop($line)) break;
      }
    }
    
    // Check that the response from the proxy is 200
    if (Zend_Http_Response::extractCode($response) != 200) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Unable to connect to HTTPS proxy. Server response: " . $response);
    }
    
    // If all is good, switch socket to secure mode. We have to fall back
    // through the different modes 
    $modes = array(STREAM_CRYPTO_METHOD_TLS_CLIENT, 
        STREAM_CRYPTO_METHOD_SSLv3_CLIENT, STREAM_CRYPTO_METHOD_SSLv23_CLIENT, 
        STREAM_CRYPTO_METHOD_SSLv2_CLIENT);
    
    $success = false;
    foreach ($modes as $mode) {
      $success = stream_socket_enable_crypto($this->socket, true, $mode);
      if ($success) break;
    }
    
    if (! $success) {
      require_once 'external/Zend/Http/Client/Adapter/Exception.php';
      throw new Zend_Http_Client_Adapter_Exception("Unable to connect to" . " HTTPS server through proxy: could not negotiate secure connection.");
    }
  }

  /**
   * Close the connection to the server
   *
   */
  public function close() {
    parent::close();
    $this->negotiated = false;
  }

  /**
   * Destructor: make sure the socket is disconnected
   *
   */
  public function __destruct() {
    if ($this->socket) $this->close();
  }
}