friendica/src/Util/Proxy.php
2022-01-02 08:27:47 +01:00

209 lines
5.3 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2010-2022, the Friendica project
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
namespace Friendica\Util;
use Friendica\Core\Logger;
use Friendica\Core\System;
use Friendica\DI;
/**
* Proxy utilities class
*/
class Proxy
{
/**
* Sizes constants
*/
const SIZE_MICRO = 'micro'; // 48
const SIZE_THUMB = 'thumb'; // 80
const SIZE_SMALL = 'small'; // 300
const SIZE_MEDIUM = 'medium'; // 600
const SIZE_LARGE = 'large'; // 1024
/**
* Pixel Sizes
*/
const PIXEL_MICRO = 48;
const PIXEL_THUMB = 80;
const PIXEL_SMALL = 300;
const PIXEL_MEDIUM = 600;
const PIXEL_LARGE = 1024;
/**
* Accepted extensions
*
* @var array
* @todo Make this configurable?
*/
private static $extensions = [
'jpg',
'jpeg',
'gif',
'png',
];
/**
* Private constructor
*/
private function __construct () {
// No instances from utilities classes
}
/**
* Transform a remote URL into a local one.
*
* This function only performs the URL replacement on http URL and if the
* provided URL isn't local
*
* @param string $url The URL to proxyfy
* @param string $size One of the Proxy::SIZE_* constants
*
* @return string The proxyfied URL or relative path
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function proxifyUrl($url, $size = '')
{
if (!DI::config()->get('system', 'proxify_content')) {
return $url;
}
// Trim URL first
$url = trim($url);
// Quit if not an HTTP/HTTPS link or if local
if (!in_array(parse_url($url, PHP_URL_SCHEME), ['http', 'https']) || self::isLocalImage($url)) {
return $url;
}
// Image URL may have encoded ampersands for display which aren't desirable for proxy
$url = html_entity_decode($url, ENT_NOQUOTES, 'utf-8');
$shortpath = hash('md5', $url);
$longpath = substr($shortpath, 0, 2);
$longpath .= '/' . strtr(base64_encode($url), '+/', '-_');
// Extract the URL extension
$extension = pathinfo(parse_url($url, PHP_URL_PATH), PATHINFO_EXTENSION);
if (in_array($extension, self::$extensions)) {
$shortpath .= '.' . $extension;
$longpath .= '.' . $extension;
}
$proxypath = DI::baseUrl() . '/proxy/' . $longpath;
if ($size != '') {
$size = ':' . $size;
}
Logger::info('Created proxy link', ['url' => $url, 'callstack' => System::callstack(20)]);
// Too long files aren't supported by Apache
if (strlen($proxypath) > 250) {
return DI::baseUrl() . '/proxy/' . $shortpath . '?url=' . urlencode($url);
} else {
return $proxypath . $size;
}
}
/**
* "Proxifies" HTML code's image tags
*
* "Proxifies", means replaces image URLs in given HTML code with those from
* proxy storage directory.
*
* @param string $html Un-proxified HTML code
*
* @return string Proxified HTML code
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function proxifyHtml($html)
{
$html = str_replace(Strings::normaliseLink(DI::baseUrl()) . '/', DI::baseUrl() . '/', $html);
return preg_replace_callback('/(<img [^>]*src *= *["\'])([^"\']+)(["\'][^>]*>)/siU', 'self::replaceUrl', $html);
}
/**
* Checks if the URL is a local URL.
*
* @param string $url
* @return boolean
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
public static function isLocalImage($url)
{
if (substr($url, 0, 1) == '/') {
return true;
}
if (strtolower(substr($url, 0, 5)) == 'data:') {
return true;
}
return Network::isLocalLink($url);
}
/**
* Return the array of query string parameters from a URL
*
* @param string $url URL to parse
* @return array Associative array of query string parameters
*/
private static function parseQuery($url)
{
$query = parse_url($url, PHP_URL_QUERY);
$query = html_entity_decode($query);
parse_str($query, $arr);
return $arr;
}
/**
* Call-back method to replace the UR
*
* @param array $matches Matches from preg_replace_callback()
* @return string Proxified HTML image tag
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
private static function replaceUrl(array $matches)
{
// if the picture seems to be from another picture cache then take the original source
$queryvar = self::parseQuery($matches[2]);
if (!empty($queryvar['url']) && substr($queryvar['url'], 0, 4) == 'http') {
$matches[2] = urldecode($queryvar['url']);
}
// Following line changed per bug #431
if (self::isLocalImage($matches[2])) {
return $matches[1] . $matches[2] . $matches[3];
}
// Return proxified HTML
return $matches[1] . self::proxifyUrl(htmlspecialchars_decode($matches[2])) . $matches[3];
}
}