friendica-github/mod/proxy.php
2018-02-03 08:56:55 -05:00

375 lines
11 KiB
PHP

<?php
/**
* @file mod/proxy.php
* @brief Based upon "Privacy Image Cache" by Tobias Hößl <https://github.com/CatoTH/>
*/
use Friendica\App;
use Friendica\Core\Config;
use Friendica\Core\System;
use Friendica\Database\DBM;
use Friendica\Model\Photo;
use Friendica\Object\Image;
use Friendica\Util\DateTimeFormat;
use Friendica\Util\Network;
define('PROXY_DEFAULT_TIME', 86400); // 1 Day
define('PROXY_SIZE_MICRO', 'micro');
define('PROXY_SIZE_THUMB', 'thumb');
define('PROXY_SIZE_SMALL', 'small');
define('PROXY_SIZE_MEDIUM', 'medium');
define('PROXY_SIZE_LARGE', 'large');
require_once 'include/security.php';
function proxy_init(App $a) {
// Pictures are stored in one of the following ways:
// 1. If a folder "proxy" exists and is writeable, then use this for caching
// 2. If a cache path is defined, use this
// 3. If everything else failed, cache into the database
//
// Question: Do we really need these three methods?
if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
header('HTTP/1.1 304 Not Modified');
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
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');
}
exit;
}
if (function_exists('header_remove')) {
header_remove('Pragma');
header_remove('pragma');
}
$thumb = false;
$size = 1024;
$sizetype = '';
$basepath = $a->get_basepath();
// If the cache path isn't there, try to create it
if (!is_dir($basepath . '/proxy') && is_writable($basepath)) {
mkdir($basepath . '/proxy');
}
// Checking if caching into a folder in the webroot is activated and working
$direct_cache = (is_dir($basepath . '/proxy') && is_writable($basepath . '/proxy'));
// Look for filename in the arguments
if ((isset($a->argv[1]) || isset($a->argv[2]) || isset($a->argv[3])) && !isset($_REQUEST['url'])) {
if (isset($a->argv[3])) {
$url = $a->argv[3];
} elseif (isset($a->argv[2])) {
$url = $a->argv[2];
} else {
$url = $a->argv[1];
}
if (isset($a->argv[3]) && ($a->argv[3] == 'thumb')) {
$size = 200;
}
// thumb, small, medium and large.
if (substr($url, -6) == ':micro') {
$size = 48;
$sizetype = ':micro';
$url = substr($url, 0, -6);
} elseif (substr($url, -6) == ':thumb') {
$size = 80;
$sizetype = ':thumb';
$url = substr($url, 0, -6);
} elseif (substr($url, -6) == ':small') {
$size = 175;
$url = substr($url, 0, -6);
$sizetype = ':small';
} elseif (substr($url, -7) == ':medium') {
$size = 600;
$url = substr($url, 0, -7);
$sizetype = ':medium';
} elseif (substr($url, -6) == ':large') {
$size = 1024;
$url = substr($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);
if ($url) {
$_REQUEST['url'] = $url;
}
} else {
$direct_cache = false;
}
if (!$direct_cache) {
$urlhash = 'pic:' . sha1($_REQUEST['url']);
$cachefile = get_cachefile(hash('md5', $_REQUEST['url']));
if ($cachefile != '' && file_exists($cachefile)) {
$img_str = file_get_contents($cachefile);
$mime = image_type_to_mime_type(exif_imagetype($cachefile));
header('Content-type: ' . $mime);
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
header('Etag: "' . md5($img_str) . '"');
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + (31536000)) . ' GMT');
header('Cache-Control: max-age=31536000');
// reduce quality - if it isn't a GIF
if ($mime != 'image/gif') {
$Image = new Image($img_str, $mime);
if ($Image->isValid()) {
$img_str = $Image->asString();
}
}
echo $img_str;
killme();
}
} else {
$cachefile = '';
}
$valid = true;
$photo = null;
if (!$direct_cache && ($cachefile == '')) {
$photo = dba::selectFirst('photo', ['data', 'desc'], ['resource-id' => $urlhash]);
if (DBM::is_result($photo)) {
$img_str = $photo['data'];
$mime = $photo['desc'];
if ($mime == '') {
$mime = 'image/jpeg';
}
}
}
if (!DBM::is_result($photo)) {
// It shouldn't happen but it does - spaces in URL
$_REQUEST['url'] = str_replace(' ', '+', $_REQUEST['url']);
$redirects = 0;
$img_str = Network::fetchUrl($_REQUEST['url'], true, $redirects, 10);
$tempfile = tempnam(get_temppath(), 'cache');
file_put_contents($tempfile, $img_str);
$mime = image_type_to_mime_type(exif_imagetype($tempfile));
unlink($tempfile);
// If there is an error then return a blank image
if ((substr($a->get_curl_code(), 0, 1) == '4') || (!$img_str)) {
$img_str = file_get_contents('images/blank.png');
$mime = 'image/png';
$cachefile = ''; // Clear the cachefile so that the dummy isn't stored
$valid = false;
$Image = new Image($img_str, 'image/png');
if ($Image->isValid()) {
$Image->scaleDown(10);
$img_str = $Image->asString();
}
} elseif ($mime != 'image/jpeg' && !$direct_cache && $cachefile == '') {
$image = @imagecreatefromstring($img_str);
if ($image === FALSE) {
die();
}
$fields = ['uid' => 0, 'contact-id' => 0, 'guid' => get_guid(), 'resource-id' => $urlhash, 'created' => DateTimeFormat::utcNow(), 'edited' => DateTimeFormat::utcNow(),
'filename' => basename($_REQUEST['url']), 'type' => '', 'album' => '', 'height' => imagesy($image), 'width' => imagesx($image),
'datasize' => 0, 'data' => $img_str, 'scale' => 100, 'profile' => 0,
'allow_cid' => '', 'allow_gid' => '', 'deny_cid' => '', 'deny_gid' => '', 'desc' => $mime];
dba::insert('photo', $fields);
} else {
$Image = new Image($img_str, $mime);
if ($Image->isValid() && !$direct_cache && ($cachefile == '')) {
Photo::store($Image, 0, 0, $urlhash, $_REQUEST['url'], '', 100);
}
}
}
$img_str_orig = $img_str;
// reduce quality - if it isn't a GIF
if ($mime != 'image/gif') {
$Image = new Image($img_str, $mime);
if ($Image->isValid()) {
$Image->scaleDown($size);
$img_str = $Image->asString();
}
}
// If there is a real existing directory then put the cache file there
// advantage: real file access is really fast
// Otherwise write in cachefile
if ($valid && $direct_cache) {
file_put_contents($basepath . '/proxy/' . proxy_url($_REQUEST['url'], true), $img_str_orig);
if ($sizetype != '') {
file_put_contents($basepath . '/proxy/' . proxy_url($_REQUEST['url'], true) . $sizetype, $img_str);
}
} elseif ($cachefile != '') {
file_put_contents($cachefile, $img_str_orig);
}
header('Content-type: ' . $mime);
// Only output the cache headers when the file is valid
if ($valid) {
header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
header('Etag: "' . md5($img_str) . '"');
header('Expires: ' . gmdate('D, d M Y H:i:s', time() + (31536000)) . ' GMT');
header('Cache-Control: max-age=31536000');
}
echo $img_str;
killme();
}
/**
* @brief 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, "the isn't deactivated" (sic) and if the config
* system.proxy_disabled is set to false.
*
* @param string $url The URL to proxyfy
* @param bool $writemode Returns a local path the remote URL should be saved to
* @param string $size One of the PROXY_SIZE_* constants
*
* @return string The proxyfied URL or relative path
*/
function proxy_url($url, $writemode = false, $size = '') {
$a = get_app();
if (substr($url, 0, strlen('http')) !== 'http') {
return $url;
}
// Only continue if it isn't a local image and the isn't deactivated
if (proxy_is_local_image($url)) {
$url = str_replace(normalise_link(System::baseUrl()) . '/', System::baseUrl() . '/', $url);
return $url;
}
if (Config::get('system', 'proxy_disabled')) {
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');
// Creating a sub directory to reduce the amount of files in the cache directory
$basepath = $a->get_basepath() . '/proxy';
$shortpath = hash('md5', $url);
$longpath = substr($shortpath, 0, 2);
if (is_dir($basepath) && $writemode && !is_dir($basepath . '/' . $longpath)) {
mkdir($basepath . '/' . $longpath);
chmod($basepath . '/' . $longpath, 0777);
}
$longpath .= '/' . strtr(base64_encode($url), '+/', '-_');
// Extract the URL extension
$extension = pathinfo(parse_url($url, PHP_URL_PATH), PATHINFO_EXTENSION);
$extensions = ['jpg', 'jpeg', 'gif', 'png'];
if (in_array($extension, $extensions)) {
$shortpath .= '.' . $extension;
$longpath .= '.' . $extension;
}
$proxypath = System::baseUrl() . '/proxy/' . $longpath;
if ($size != '') {
$size = ':' . $size;
}
// Too long files aren't supported by Apache
// Writemode in combination with long files shouldn't be possible
if ((strlen($proxypath) > 250) && $writemode) {
return $shortpath;
} elseif (strlen($proxypath) > 250) {
return System::baseUrl() . '/proxy/' . $shortpath . '?url=' . urlencode($url);
} elseif ($writemode) {
return $longpath;
} else {
return $proxypath . $size;
}
}
/**
* @param $url string
* @return boolean
*/
function proxy_is_local_image($url) {
if ($url[0] == '/') {
return true;
}
if (strtolower(substr($url, 0, 5)) == 'data:') {
return true;
}
// links normalised - bug #431
$baseurl = normalise_link(System::baseUrl());
$url = normalise_link($url);
return (substr($url, 0, strlen($baseurl)) == $baseurl);
}
/**
* @brief Return the array of query string parameters from a URL
*
* @param string $url
* @return array Associative array of query string parameters
*/
function proxy_parse_query($url) {
$query = parse_url($url, PHP_URL_QUERY);
$query = html_entity_decode($query);
$query_list = explode('&', $query);
$arr = [];
foreach ($query_list as $key_value) {
$key_value_list = explode('=', $key_value);
$arr[$key_value_list[0]] = $key_value_list[1];
}
unset($url, $query_list, $url);
return $arr;
}
function proxy_img_cb($matches) {
// if the picture seems to be from another picture cache then take the original source
$queryvar = proxy_parse_query($matches[2]);
if (($queryvar['url'] != '') && (substr($queryvar['url'], 0, 4) == 'http')) {
$matches[2] = urldecode($queryvar['url']);
}
// following line changed per bug #431
if (proxy_is_local_image($matches[2])) {
return $matches[1] . $matches[2] . $matches[3];
}
return $matches[1] . proxy_url(htmlspecialchars_decode($matches[2])) . $matches[3];
}
function proxy_parse_html($html) {
$html = str_replace(normalise_link(System::baseUrl()) . '/', System::baseUrl() . '/', $html);
return preg_replace_callback('/(<img [^>]*src *= *["\'])([^"\']+)(["\'][^>]*>)/siU', 'proxy_img_cb', $html);
}