<?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 25273 2013-03-06 08:02:21Z frosch $

 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/**

 * @see Zend_Uri_Http

 */

require_once 'Zend/Uri/Http.php';

/**

 * @see Zend_Http_Client

 */

require_once 'Zend/Http/Client.php';

/**

 * @see Zend_Http_Client_Adapter_Socket

 */

require_once '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) 2005-2012 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',

        'sslcert'       => null,

        'sslpassphrase' => null,

        'sslusecontext' => false,

        'proxy_host'    => '',

        'proxy_port'    => 8080,

        'proxy_user'    => '',

        'proxy_pass'    => '',

        'proxy_auth'    => Zend_Http_Client::AUTH_BASIC,

        'persistent'    => false,

    );

    /**

     * Whether HTTPS CONNECT was already negotiated with the proxy or not

     *

     * @var boolean

     */

    protected $negotiated = false;

    /**

     * Stores the last CONNECT handshake request

     * 

     * @var string

     */

    protected $connectHandshakeRequest;

    /**

     * 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

     */

    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);

        }

        /* Url might require stream context even if proxy connection doesn't */

        if ($secure) {

            $this->config['sslusecontext'] = true;

        }

        // Connect (a non-secure connection) to the proxy server

        return parent::connect(

            $this->config['proxy_host'],

            $this->config['proxy_port'],

            false

        );

    }

    /**

     * 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

     * @throws Zend_Http_Client_Adapter_Exception

     */

    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 '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 ($this->connected_to[0] != "tcp://$host"

            || $this->connected_to[1] != $port

        ) {

            require_once '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']) {

            // Check to see if one already exists

            $hasProxyAuthHeader = false;

            foreach ($headers as $k => $v) {

                if ((string) $k == 'proxy-authorization'

                    || preg_match("/^proxy-authorization:/i", $v)

                ) {

                    $hasProxyAuthHeader = true;

                    break;

                }

            }

            if (!$hasProxyAuthHeader) {

                $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

        if ($this->negotiated) {

            $path = $uri->getPath();

            if ($uri->getQuery()) {

                $path .= '?' . $uri->getQuery();

            }

            $request = "$method $path HTTP/$http_ver\r\n";

        } else {

            $request = "$method $uri HTTP/$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";

        }

        if(is_resource($body)) {

            $request .= "\r\n";

        } else {

            // Add the request body

            $request .= "\r\n" . $body;

        }

        // Send the request

        if (!@fwrite($this->socket, $request)) {

            require_once 'Zend/Http/Client/Adapter/Exception.php';

            throw new Zend_Http_Client_Adapter_Exception(

                'Error writing request to proxy server'

            );

        }

        if(is_resource($body)) {

            if(stream_copy_to_stream($body, $this->socket) == 0) {

                require_once 'Zend/Http/Client/Adapter/Exception.php';

                throw new Zend_Http_Client_Adapter_Exception(

                    'Error writing request to server'

                );

            }

        }

        return $request;

    }

    /**

     * Preform handshaking with HTTPS proxy using CONNECT method

     *

     * @param string  $host

     * @param integer $port

     * @param string  $http_ver

     * @param array   $headers

     * @return void

     * @throws Zend_Http_Client_Adapter_Exception

     */

    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";

        // Process provided headers, including important ones to CONNECT request

        foreach ($headers as $k => $v) {

            switch (strtolower(substr($v,0,strpos($v,':')))) {

                case 'proxy-authorization':

                    // break intentionally omitted

                case 'user-agent':

                    $request .= $v . "\r\n";

                    break;

                default:

                    break;

            }

        }

        $request .= "\r\n";

        // @see ZF-3189

        $this->connectHandshakeRequest = $request;

        // Send the request

        if (!@fwrite($this->socket, $request)) {

            require_once '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 '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 '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();

        }

    }

}