Subversion Repositories cheapmusic

<?php

/**

 * Copyright 2017 Facebook, Inc.

 *

 * You are hereby granted a non-exclusive, worldwide, royalty-free license to

 * use, copy, modify, and distribute this software in source code or binary

 * form for use in connection with the web services and APIs provided by

 * Facebook.

 *

 * As with any software that integrates with the Facebook platform, your use

 * of this software is subject to the Facebook Developer Principles and

 * Policies [http://developers.facebook.com/policy/]. This copyright 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.

 *

 */

namespace Facebook\Url;

/**

 * Class FacebookUrlDetectionHandler

 *

 * @package Facebook

 */

class FacebookUrlDetectionHandler implements UrlDetectionInterface

{

    /**

     * @inheritdoc

     */

    public function getCurrentUrl()

    {

        return $this->getHttpScheme() . '://' . $this->getHostName() . $this->getServerVar('REQUEST_URI');

    }

    /**

     * Get the currently active URL scheme.

     *

     * @return string

     */

    protected function getHttpScheme()

    {

        return $this->isBehindSsl() ? 'https' : 'http';

    }

    /**

     * Tries to detect if the server is running behind an SSL.

     *

     * @return boolean

     */

    protected function isBehindSsl()

    {

        // Check for proxy first

        $protocol = $this->getHeader('X_FORWARDED_PROTO');

        if ($protocol) {

            return $this->protocolWithActiveSsl($protocol);

        }

        $protocol = $this->getServerVar('HTTPS');

        if ($protocol) {

            return $this->protocolWithActiveSsl($protocol);

        }

        return (string)$this->getServerVar('SERVER_PORT') === '443';

    }

    /**

     * Detects an active SSL protocol value.

     *

     * @param string $protocol

     *

     * @return boolean

     */

    protected function protocolWithActiveSsl($protocol)

    {

        $protocol = strtolower((string)$protocol);

        return in_array($protocol, ['on', '1', 'https', 'ssl'], true);

    }

    /**

     * Tries to detect the host name of the server.

     *

     * Some elements adapted from

     *

     * @see https://github.com/symfony/HttpFoundation/blob/master/Request.php

     *

     * @return string

     */

    protected function getHostName()

    {

        // Check for proxy first

        $header = $this->getHeader('X_FORWARDED_HOST');

        if ($header && $this->isValidForwardedHost($header)) {

            $elements = explode(',', $header);

            $host = $elements[count($elements) - 1];

        } elseif (!$host = $this->getHeader('HOST')) {

            if (!$host = $this->getServerVar('SERVER_NAME')) {

                $host = $this->getServerVar('SERVER_ADDR');

            }

        }

        // trim and remove port number from host

        // host is lowercase as per RFC 952/2181

        $host = strtolower(preg_replace('/:\d+$/', '', trim($host)));

        // Port number

        $scheme = $this->getHttpScheme();

        $port = $this->getCurrentPort();

        $appendPort = ':' . $port;

        // Don't append port number if a normal port.

        if (($scheme == 'http' && $port == '80') || ($scheme == 'https' && $port == '443')) {

            $appendPort = '';

        }

        return $host . $appendPort;

    }

    protected function getCurrentPort()

    {

        // Check for proxy first

        $port = $this->getHeader('X_FORWARDED_PORT');

        if ($port) {

            return (string)$port;

        }

        $protocol = (string)$this->getHeader('X_FORWARDED_PROTO');

        if ($protocol === 'https') {

            return '443';

        }

        return (string)$this->getServerVar('SERVER_PORT');

    }

    /**

     * Returns the a value from the $_SERVER super global.

     *

     * @param string $key

     *

     * @return string

     */

    protected function getServerVar($key)

    {

        return isset($_SERVER[$key]) ? $_SERVER[$key] : '';

    }

    /**

     * Gets a value from the HTTP request headers.

     *

     * @param string $key

     *

     * @return string

     */

    protected function getHeader($key)

    {

        return $this->getServerVar('HTTP_' . $key);

    }

    /**

     * Checks if the value in X_FORWARDED_HOST is a valid hostname

     * Could prevent unintended redirections

     *

     * @param string $header

     *

     * @return boolean

     */

    protected function isValidForwardedHost($header)

    {

        $elements = explode(',', $header);

        $host = $elements[count($elements) - 1];

        return preg_match("/^([a-z\d](-*[a-z\d])*)(\.([a-z\d](-*[a-z\d])*))*$/i", $host) //valid chars check

            && 0 < strlen($host) && strlen($host) < 254 //overall length check

            && preg_match("/^[^\.]{1,63}(\.[^\.]{1,63})*$/", $host); //length of each label

    }

}