friendica-github/src/Module/Proxy.php

203 lines
5.9 KiB
PHP

<?php
/**
* @copyright Copyright (C) 2010-2021, 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\Module;
use Friendica\BaseModule;
use Friendica\Core\Logger;
use Friendica\Core\System;
use Friendica\DI;
use Friendica\Network\HTTPException\NotModifiedException;
use Friendica\Object\Image;
use Friendica\Util\HTTPSignature;
use Friendica\Util\Images;
use Friendica\Util\Proxy as ProxyUtils;
/**
* Module Proxy
*
* urls:
* /proxy/[sub1/[sub2/]]<base64url image url>[.ext][:size]
* /proxy?url=<image url>
*/
class Proxy extends BaseModule
{
/**
* Fetch remote image content
*/
public function rawContent()
{
$request = $this->getRequestInfo();
if (!DI::config()->get('system', 'proxify_content')) {
Logger::notice('Proxy access is forbidden', ['request' => $request, 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '', 'accept' => $_SERVER['HTTP_ACCEPT'] ?? '']);
throw new \Friendica\Network\HTTPException\NotFoundException();
}
if (isset($_SERVER["HTTP_IF_MODIFIED_SINCE"])) {
header("Last-Modified: " . gmdate("D, d M Y H:i:s", time()) . " GMT");
if (!empty($_SERVER["HTTP_IF_NONE_MATCH"])) {
header("Etag: " . $_SERVER["HTTP_IF_NONE_MATCH"]);
}
header("Expires: " . gmdate("D, d M Y H:i:s", time() + (31536000)) . " GMT");
header("Cache-Control: max-age=31536000");
if (function_exists("header_remove")) {
header_remove("Last-Modified");
header_remove("Expires");
header_remove("Cache-Control");
}
throw new NotModifiedException();
}
if (empty($request['url'])) {
throw new \Friendica\Network\HTTPException\BadRequestException();
}
if (!local_user()) {
Logger::info('Redirecting not logged in user to original address', ['url' => $request['url']]);
System::externalRedirect($request['url']);
}
// It shouldn't happen but it does - spaces in URL
$request['url'] = str_replace(' ', '+', $request['url']);
// Fetch the content with the local user
$fetchResult = HTTPSignature::fetchRaw($request['url'], local_user(), ['accept_content' => [], 'timeout' => 10]);
$img_str = $fetchResult->getBody();
if (!$fetchResult->isSuccess() || empty($img_str)) {
Logger::info('Error fetching image', ['image' => $request['url'], 'return' => $fetchResult->getReturnCode(), 'empty' => empty($img_str)]);
self::responseError();
// stop.
}
$mime = Images::getMimeTypeByData($img_str);
$image = new Image($img_str, $mime);
if (!$image->isValid()) {
Logger::info('The image is invalid', ['image' => $request['url'], 'mime' => $mime]);
self::responseError();
// stop.
}
// reduce quality - if it isn't a GIF
if ($image->getType() != 'image/gif') {
$image->scaleDown($request['size']);
}
self::responseImageHttpCache($image);
// stop.
}
/**
* Build info about requested image to be proxied
*
* @return array
* [
* 'url' => requested url,
* 'size' => requested image size (int)
* 'sizetype' => requested image size (string): ':micro', ':thumb', ':small', ':medium', ':large'
* ]
* @throws \Exception
*/
private function getRequestInfo()
{
$size = ProxyUtils::PIXEL_LARGE;
$sizetype = '';
if (!empty($this->parameters['url']) && empty($_REQUEST['url'])) {
$url = $this->parameters['url'];
// thumb, small, medium and large.
if (substr($url, -6) == ':micro') {
$size = ProxyUtils::PIXEL_MICRO;
$sizetype = ':micro';
$url = substr($url, 0, -6);
} elseif (substr($url, -6) == ':thumb') {
$size = ProxyUtils::PIXEL_THUMB;
$sizetype = ':thumb';
$url = substr($url, 0, -6);
} elseif (substr($url, -6) == ':small') {
$size = ProxyUtils::PIXEL_SMALL;
$url = substr($url, 0, -6);
$sizetype = ':small';
} elseif (substr($url, -7) == ':medium') {
$size = ProxyUtils::PIXEL_MEDIUM;
$url = substr($url, 0, -7);
$sizetype = ':medium';
} elseif (substr($url, -6) == ':large') {
$size = ProxyUtils::PIXEL_LARGE;
$url = substr($url, 0, -6);
$sizetype = ':large';
}
$pos = strrpos($url, '=.');
if ($pos) {
$url = substr($url, 0, $pos + 1);
}
$url = str_replace(['.jpg', '.jpeg', '.gif', '.png'], ['','','',''], $url);
$url = base64_decode(strtr($url, '-_', '+/'), true);
} else {
$url = $_REQUEST['url'] ?? '';
}
return [
'url' => $url,
'size' => $size,
'sizetype' => $sizetype,
];
}
/**
* In case of an error just stop. We don't return content to avoid caching problems
*
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
private static function responseError()
{
throw new \Friendica\Network\HTTPException\InternalServerErrorException();
}
/**
* Output the image with cache headers
*
* @param Image $img
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
private static function responseImageHttpCache(Image $img)
{
if (is_null($img) || !$img->isValid()) {
Logger::info('The cached image is invalid');
self::responseError();
// stop.
}
header('Content-type: ' . $img->getType());
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
header('Etag: "' . md5($img->asString()) . '"');
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + (31536000)) . ' GMT');
header('Cache-Control: max-age=31536000');
echo $img->asString();
exit();
}
}