From 33ccf200cb441a15d77c0be4b4059fb620d9b92f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tobias=20H=C3=B6=C3=9Fl?= Date: Sun, 22 Apr 2012 13:19:45 +0000 Subject: [PATCH] Privacy Image Cache --- privacy_image_cache/README.md | 4 + privacy_image_cache/privacy_image_cache.php | 175 ++++++++++++++++++++ 2 files changed, 179 insertions(+) create mode 100644 privacy_image_cache/README.md create mode 100644 privacy_image_cache/privacy_image_cache.php diff --git a/privacy_image_cache/README.md b/privacy_image_cache/README.md new file mode 100644 index 00000000..63970d3d --- /dev/null +++ b/privacy_image_cache/README.md @@ -0,0 +1,4 @@ +Once activated, this addon acs as a proxy between the user and external image resources. +If external images are to be shown, like avatars or embedded images, the server retrieves the image and the local link is sent to the user. +By using this proxy, the server hosting the original image cannot retrieve personal information of the user like the IP address, User Agent or Cookies. +However, the remote server will be able to track the IP address of the server hosting the friendica installation. \ No newline at end of file diff --git a/privacy_image_cache/privacy_image_cache.php b/privacy_image_cache/privacy_image_cache.php new file mode 100644 index 00000000..45aeb080 --- /dev/null +++ b/privacy_image_cache/privacy_image_cache.php @@ -0,0 +1,175 @@ + + */ + +define("PRIVACY_IMAGE_CACHE_DEFAULT_TIME", 86400); // 1 Day + +require_once('include/security.php'); + +function privacy_image_cache_install() { + register_hook('bbcode', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_bbcode_hook'); + register_hook('display_item', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_display_item_hook'); + register_hook('ping_xmlize', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_ping_xmlize_hook'); + register_hook('cron', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_cron'); +} + + +function privacy_image_cache_uninstall() { + unregister_hook('bbcode', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_bbcode_hook'); + unregister_hook('display_item', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_display_item_hook'); + unregister_hook('ping_xmlize', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_ping_xmlize_hook'); + unregister_hook('cron', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_cron'); +} + + +function privacy_image_cache_module() {} + + +function privacy_image_cache_init() { + $urlhash = 'pic:' . sha1($_REQUEST['url']); + $r = q("SELECT * FROM `photo` WHERE `resource-id` = '%s' LIMIT 1", $urlhash ); + if (count($r)) { + $img_str = $r[0]['data']; + } + else { + require_once("Photo.php"); + + $img_str = fetch_url($_REQUEST['url'],true); + $img = new Photo($img_str); + if($img->is_valid()) { + $img->store(0, 0, $urlhash, $_REQUEST['url'], '', 100); + $img_str = $img->imageString(); + } + } + + + header("Content-type: image/jpeg"); + header("Expires: " . gmdate("D, d M Y H:i:s", time() + (3600*24)) . " GMT"); + header("Cache-Control: max-age=" . (3600*24)); + + echo $img_str; + + killme(); +} + +/** + * @param $url string + * @return boolean + */ +function privacy_image_cache_is_local_image($url) { + if ($url[0] == '/') return true; + $baseurl = get_app()->get_baseurl(); + return (substr($url, 0, strlen($baseurl)) == $baseurl); +} + +/** + * @param array $matches + * @return string + */ +function privacy_image_cache_img_cb($matches) { + if (privacy_image_cache_is_local_image($matches[2])) return $matches[2]; + return $matches[1] . "/privacy_image_cache/?url=" . escape_tags(addslashes($matches[2])) . $matches[3]; +} + +/** + * @param App $a + * @param string $o + */ +function privacy_image_cache_bbcode_hook(&$a, &$o) { + $o = preg_replace_callback("/(]*src *= *[\"'])([^\"']+)([\"'][^>]*>)/siU", "privacy_image_cache_img_cb", $o); +} + + +/** + * @param App $a + * @param string $o + */ +function privacy_image_cache_display_item_hook(&$a, &$o) { + if (isset($o["output"])) { + if (isset($o["output"]["thumb"]) && !privacy_image_cache_is_local_image($o["output"]["thumb"])) + $o["output"]["thumb"] = "/privacy_image_cache/?url=" . escape_tags(addslashes($o["output"]["thumb"])); + if (isset($o["output"]["author-avatar"]) && !privacy_image_cache_is_local_image($o["output"]["author-avatar"])) + $o["output"]["author-avatar"] = "/privacy_image_cache/?url=" . escape_tags(addslashes($o["output"]["author-avatar"])); + } +} + + +/** + * @param App $a + * @param string $o + */ +function privacy_image_cache_ping_xmlize_hook(&$a, &$o) { + if ($o["photo"] != "" && !privacy_image_cache_is_local_image($o["photo"])) + $o["photo"] = "/privacy_image_cache/?url=" . escape_tags(addslashes($o["photo"])); +} + + +/** + * @param App $a + * @param null|object $b + */ +function privacy_image_cache_cron(&$a, &$b) { + $cachetime = get_config('privacy_image_cache','cache_time'); + if (!$cachetime) $cachetime = PRIVACY_IMAGE_CACHE_DEFAULT_TIME; + + $last = get_config('pi_cache','last_delete'); + $time = time(); + if ($time < ($last + 3600)) return; + + logger("Purging old Cache of the Privacy Image Cache", LOGGER_DEBUG); + q('DELETE FROM `photo` WHERE `uid` = 0 AND `resource-id` LIKE "pic:%%" AND `created` < NOW() - INTERVAL %d SECOND', $cachetime); + set_config('pi_cache', 'last_delete', $time); +} + + + + +/** + * @param App $a + * @param null|object $o + */ +function privacy_image_cache_plugin_admin(&$a, &$o){ + + + $o = ''; + + $cachetime = get_config('privacy_image_cache','cache_time'); + if (!$cachetime) $cachetime = PRIVACY_IMAGE_CACHE_DEFAULT_TIME; + $cachetime_h = Ceil($cachetime / 3600); + + $o .= ' +
'; + + $o .= ''; + + $o .= '

' . t('Cache Statistics') . '

'; + + $num = q('SELECT COUNT(*) num, SUM(LENGTH(data)) size FROM `photo` WHERE `uid`=0 AND `contact-id`=0 AND `resource-id` LIKE "pic:%%"'); + $o .= '
'; + $size = Ceil($num[0]['size'] / (1024 * 1024)); + $o .= '
'; + + $o .= ''; +} + + +/** + * @param App $a + * @param null|object $o + */ +function privacy_image_cache_plugin_admin_post(&$a, &$o){ + check_form_security_token_redirectOnErr('/admin/plugins/privacy_image_cache', 'picsave'); + + if (isset($_REQUEST['save'])) { + $cachetime_h = IntVal($_REQUEST['cachetime']); + if ($cachetime_h < 1) $cachetime_h = 1; + set_config('privacy_image_cache','cache_time', $cachetime_h * 3600); + } + if (isset($_REQUEST['delete_all'])) { + q('DELETE FROM `photo` WHERE `uid` = 0 AND `resource-id` LIKE "pic:%%"'); + } +} \ No newline at end of file