ui: update pdf link processing

packages/ui-default/backendlib/markdown-it-media.ts

@@ -3,7 +3,6 @@
 /* eslint-disable regexp/no-useless-non-capturing-group */
 /* eslint-disable regexp/optimal-quantifier-concatenation */
 
-import _ from 'lodash';
 import type MarkdownIt from 'markdown-it';
 import { v4 as uuid } from 'uuid';
 
@@ -77,13 +76,22 @@ function resourceUrl(service: string, src: string, url: string) {
   if (service === 'vimeo') return `https://player.vimeo.com/video/${src}`;
   if (service === 'vine') return `https://vine.co/v/${src}/embed/simple`;
   if (service === 'prezi') {
-    return `https://prezi.com/embed/${src}/?bgcolor=ffffff&lock_to_path=0&autoplay=0&autohide_ctrls=0&`
-      + 'landing_data=bHVZZmNaNDBIWnNjdEVENDRhZDFNZGNIUE43MHdLNWpsdFJLb2ZHanI5N1lQVHkxSHFxazZ0UUNCRHloSXZROHh3PT0&'
+    return `https://prezi.com/embed/${src}/?bgcolor=ffffff&lock_to_path=0&autoplay=0&autohide_ctrls=0&`
+      + 'landing_data=bHVZZmNaNDBIWnNjdEVENDRhZDFNZGNIUE43MHdLNWpsdFJLb2ZHanI5N1lQVHkxSHFxazZ0UUNCRHloSXZROHh3PT0&'
       + 'landing_sign=1kD6c0N6aYpMUS0wxnQjxzSqZlEB8qNFdxtdjYhwSuI';
   }
   return src;
 }
 
+function pdfUrlKind(src: string) {
+  const normalizedSrc = src.replace(/\s/g, '').replace(/\\/g, '/');
+  if (/^data:application\/pdf(?:;[^,]*)?,/i.test(normalizedSrc)) return 'data';
+  if (/^file:\/\//i.test(normalizedSrc)) return 'local';
+  if (/^https?:\/\//i.test(normalizedSrc)) return 'external';
+  if (normalizedSrc.startsWith('//') || /^[a-z][a-z\d+.-]*:/i.test(normalizedSrc)) return 'invalid';
+  return 'local';
+}
+
 declare module 'hydrooj' {
   interface ModuleInterfaces {
     richmedia: {
@@ -95,21 +103,26 @@ declare module 'hydrooj' {
 export function Media(md: MarkdownIt, { pdfToolbar = false }: { pdfToolbar?: boolean } = {}) {
   const supported = ['youtube', 'vimeo', 'vine', 'prezi', 'bilibili', 'youku', 'msoffice'];
   md.renderer.rules.video = function tokenizeReturn(tokens, idx) {
-    let src = md.utils.escapeHtml(tokens[idx].attrGet('src'));
+    const src = tokens[idx].attrGet('src');
     const service = tokens[idx].attrGet('service').replace(/[^A-Z0-9]/gi, '').toLowerCase();
     if (Hydro?.module?.richmedia?.[service]) {
       const result = Hydro?.module?.richmedia[service].get(service, src, md);
       if (result) return result;
     }
     if (service === 'pdf') {
-      if (['file://', './', '../'].some((i) => src.startsWith(i)) || (src[1] === '/' && src[2] !== '/')) src += src.includes('?') ? '&noDisposition=1' : '?noDisposition=1';
+      const kind = pdfUrlKind(src);
       // A response with has content-disposition header causes the browser to download the file automatically.
       // As we cannot control response header from external sites, we block embedding external PDFs.
-      else return `<p>Embedding an external PDF is no longer supported.</p> <a href="${_.escape(src)}">Download</a>`;
+      if (kind === 'external') return `<p>Embedding an external PDF is no longer supported.</p> <a href="${md.utils.escapeHtml(src)}">Download</a>`;
+      if (kind === 'invalid') return '<p>Embedding this PDF URL is not supported.</p>';
+      const fragmentPos = src.indexOf('#');
+      const pdfUrl = fragmentPos === -1 ? src : src.slice(0, fragmentPos);
+      const fragment = fragmentPos === -1 ? '' : src.slice(fragmentPos);
+      const pdfSrc = kind === 'data' ? src : `${pdfUrl}${pdfUrl.includes('?') ? '&' : '?'}noDisposition=1${fragment}`;
       return `\
         <object classid="clsid:${uuid().toUpperCase()}">
-          <param name="SRC" value="${src}">
-          <embed type="application/pdf" width="100%" style="min-height:100vh;border:none;" fullscreen="yes" src="${src}#toolbar=${pdfToolbar ? '0' : '1'}&navpanes=0&view=FitH">
+          <param name="SRC" value="${md.utils.escapeHtml(pdfSrc)}">
+          <embed type="application/pdf" width="100%" style="min-height:100vh;border:none;" fullscreen="yes" src="${md.utils.escapeHtml(`${pdfSrc}#toolbar=${pdfToolbar ? '0' : '1'}&navpanes=0&view=FitH`)}">
             <noembed></noembed>
           </embed>
         </object>`;
@@ -117,7 +130,7 @@ export function Media(md: MarkdownIt, { pdfToolbar = false }: { pdfToolbar?: boo
     if (['url', 'video'].includes(service)) {
       return `\
         <video width="100%" controls>
-          <source src="${src}" type="${src.endsWith('ogg') ? 'video/ogg' : 'video/mp4'}">
+          <source src="${md.utils.escapeHtml(src)}" type="${src.endsWith('ogg') ? 'video/ogg' : 'video/mp4'}">
           Your browser doesn't support video tag.
         </video>`;
     }
@@ -125,7 +138,7 @@ export function Media(md: MarkdownIt, { pdfToolbar = false }: { pdfToolbar?: boo
       return `\
       <iframe class="embed-responsive-item ${service}-player" type="text/html" \
         width="100%" style="min-height: 500px" ${allowFullScreen} \
-        src="${resourceUrl(service, src, tokens[idx].attrGet('url'))}"
+        src="${md.utils.escapeHtml(resourceUrl(service, src, tokens[idx].attrGet('url')))}"
         scrolling="no" border="0" frameborder="no" framespacing="0"></iframe>`;
     }
     return `<div data-${service}>${md.utils.escapeHtml(src)}</div>`;