From 2582d2272be177fc084a83459ab55adf8a4ddf4e Mon Sep 17 00:00:00 2001 From: glubsy Date: Sat, 23 Jan 2021 18:30:19 +0000 Subject: [PATCH 1/2] Limit thumbnail generation * This fixes a denial-of-service exploit that would allow the client to generate an infinite number of thumbnails and fill up the storage completely. Since the client had control over the requested thumbnail sizes, it could make arbitrary requests for thumbnails, and every time the backend did not find an already generated thumbnail with the specified sizes, it would happily generate a new one. * Remove the ability of the client to decide thumbnail dimensions and only let the back-end do this by reading the configuration. * Limit the number of generated thumbnails per file to only one, with "landscape" dimensions (4/3). * Use CSS "object-fit" property to adjust displaying of landscape thumbnails into squares. Ref: https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit --- src/_h5ai/private/conf/options.json | 2 +- src/_h5ai/private/php/core/class-context.php | 5 ++++- src/_h5ai/private/php/ext/class-thumb.php | 4 ++-- src/_h5ai/public/css/lib/view/view.less | 2 ++ src/_h5ai/public/js/lib/ext/thumbnails.js | 5 ----- 5 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/_h5ai/private/conf/options.json b/src/_h5ai/private/conf/options.json index a570da26..2e9e83d1 100644 --- a/src/_h5ai/private/conf/options.json +++ b/src/_h5ai/private/conf/options.json @@ -355,7 +355,7 @@ - mov: array of strings - doc: array of strings - delay: number, delay in milliseconds after "dom-ready" before thumb-requesting starts - - size: number, size in pixel of the generated thumbnails + - size: number, height in pixel of the generated thumbnails - exif: boolean, use included EXIF thumbs if possible - chunksize: int, number of thumbs per request */ diff --git a/src/_h5ai/private/php/core/class-context.php b/src/_h5ai/private/php/core/class-context.php index 0a72cea5..64c9b72c 100644 --- a/src/_h5ai/private/php/core/class-context.php +++ b/src/_h5ai/private/php/core/class-context.php @@ -23,6 +23,9 @@ class Context { $this->options = Json::load($this->setup->get('CONF_PATH') . '/options.json'); + $this->thumbnail_height = $this->options['thumbnails']['size'] ?? 240; + $this->thumbnail_width = floor($this->thumbnail_height * (4 / 3)); + $this->passhash = $this->query_option('passhash', ''); $this->options['hasCustomPasshash'] = strcasecmp($this->passhash, Context::$DEFAULT_PASSHASH) !== 0; unset($this->options['passhash']); @@ -250,7 +253,7 @@ class Context { foreach ($requests as $req) { $thumb = new Thumb($this); - $hrefs[] = $thumb->thumb($req['type'], $req['href'], $req['width'], $req['height']); + $hrefs[] = $thumb->thumb($req['type'], $req['href']); } return $hrefs; diff --git a/src/_h5ai/private/php/ext/class-thumb.php b/src/_h5ai/private/php/ext/class-thumb.php index d52d3e85..0f9823fb 100644 --- a/src/_h5ai/private/php/ext/class-thumb.php +++ b/src/_h5ai/private/php/ext/class-thumb.php @@ -23,7 +23,7 @@ class Thumb { } } - public function thumb($type, $source_href, $width, $height) { + public function thumb($type, $source_href) { $source_path = $this->context->to_path($source_href); if (!file_exists($source_path) || Util::starts_with($source_path, $this->setup->get('CACHE_PUB_PATH'))) { return null; @@ -46,7 +46,7 @@ class Thumb { } } - return $this->thumb_href($capture_path, $width, $height); + return $this->thumb_href($capture_path, $this->context->thumbnail_width, $this->context->thumbnail_height); } private function thumb_href($source_path, $width, $height) { diff --git a/src/_h5ai/public/css/lib/view/view.less b/src/_h5ai/public/css/lib/view/view.less index aef93ecb..1be5170d 100644 --- a/src/_h5ai/public/css/lib/view/view.less +++ b/src/_h5ai/public/css/lib/view/view.less @@ -48,6 +48,8 @@ .thumb { max-width: none; max-height: none; + object-fit: cover; + object-position: 50% 50%; } } diff --git a/src/_h5ai/public/js/lib/ext/thumbnails.js b/src/_h5ai/public/js/lib/ext/thumbnails.js index d71898cc..d92c1455 100644 --- a/src/_h5ai/public/js/lib/ext/thumbnails.js +++ b/src/_h5ai/public/js/lib/ext/thumbnails.js @@ -13,7 +13,6 @@ const settings = Object.assign({ exif: false, chunksize: 20 }, allsettings.thumbnails); -const landscapeRatio = 4 / 3; const queueItem = (queue, item) => { @@ -35,7 +34,6 @@ const queueItem = (queue, item) => { queue.push({ type, href: item.absHref, - ratio: 1, callback: src => { if (src && item.$view) { item.thumbSquare = src; @@ -51,7 +49,6 @@ const queueItem = (queue, item) => { queue.push({ type, href: item.absHref, - ratio: landscapeRatio, callback: src => { if (src && item.$view) { item.thumbRational = src; @@ -67,8 +64,6 @@ const requestQueue = queue => { return { type: req.type, href: req.href, - width: Math.round(settings.size * req.ratio), - height: settings.size }; }); From a2d21cfdeeac726e5b78336c9d7b0c1b23eb60ac Mon Sep 17 00:00:00 2001 From: glubsy Date: Mon, 25 Jan 2021 01:51:54 +0000 Subject: [PATCH 2/2] Remove redundant request for square thumb * We now use only one thumbnail file src for both square and rational thumbnails so remove superfluous requests. * Set the same src for both square and landscape dom classes. --- .../public/js/lib/ext/preview/preview.js | 2 +- src/_h5ai/public/js/lib/ext/thumbnails.js | 19 ++----------------- 2 files changed, 3 insertions(+), 18 deletions(-) diff --git a/src/_h5ai/public/js/lib/ext/preview/preview.js b/src/_h5ai/public/js/lib/ext/preview/preview.js index 703b2b99..d5a44fb0 100644 --- a/src/_h5ai/public/js/lib/ext/preview/preview.js +++ b/src/_h5ai/public/js/lib/ext/preview/preview.js @@ -213,7 +213,7 @@ Session.prototype = { } }); dom('#pv-container').hide().clr(); - showSpinner(true, item.thumbSquare || item.icon, 200); + showSpinner(true, item.thumbRational || item.icon, 200); }) .then(() => this.load(item)) // delay for testing diff --git a/src/_h5ai/public/js/lib/ext/thumbnails.js b/src/_h5ai/public/js/lib/ext/thumbnails.js index d92c1455..a8ef6a61 100644 --- a/src/_h5ai/public/js/lib/ext/thumbnails.js +++ b/src/_h5ai/public/js/lib/ext/thumbnails.js @@ -28,23 +28,8 @@ const queueItem = (queue, item) => { return; } - if (item.thumbSquare) { - item.$view.find('.icon.square img').addCls('thumb').attr('src', item.thumbSquare); - } else { - queue.push({ - type, - href: item.absHref, - callback: src => { - if (src && item.$view) { - item.thumbSquare = src; - item.$view.find('.icon.square img').addCls('thumb').attr('src', src); - } - } - }); - } - if (item.thumbRational) { - item.$view.find('.icon.landscape img').addCls('thumb').attr('src', item.thumbRational); + item.$view.find('.icon img').addCls('thumb').attr('src', item.thumbRational); } else { queue.push({ type, @@ -52,7 +37,7 @@ const queueItem = (queue, item) => { callback: src => { if (src && item.$view) { item.thumbRational = src; - item.$view.find('.icon.landscape img').addCls('thumb').attr('src', src); + item.$view.find('.icon img').addCls('thumb').attr('src', src); } } });