feat(fediverse): media posting for e2ee rooms [kakashi]

feat(fediverse): direct messaging and follower-only posting [kakashi]
feat(config): emoji customization available in config [kakashi]
fix(cmd): unroll by text [kakashi]
refactor(reacts): timeline minimum +4 events => timeline minimum +1 events [kakashi]
chore(deps): upgrade matrix-js-sdk, olm, qs
chore(package): bump version

commands/fediverse/post.js

@@ -1,9 +1,61 @@
 const qs = require('qs');
+const crypto = require('crypto');
 const FormData = require('form-data');
 
 const emojis = { public: '🌐', unlisted: '📝', private: '🔒️', direct: '✉️' };
 exports.visibilityEmoji = (v) => emojis[v] || v;
 
+const mediaPathRegex = /^\/_matrix\/media\/r0\/download\/[^/]+\/[^/]+\/?$/;
+
+const decryptMedia = (media, file) => {
+  const { v, key: { alg, ext, k, }, iv } = file;
+
+  if (v !== 'v2' || ext !== true || alg !== 'A256CTR')
+    throw new Error('Unsupported file encryption');
+
+  const key = Buffer.from(k, 'base64');
+  const _iv = Buffer.from(iv, 'base64');
+  const cipher = crypto.createDecipheriv('aes-256-ctr', key, _iv);
+  const data = Buffer.concat([ cipher.update(media.data), cipher.final() ]);
+  return Object.assign({}, media, { data });
+};
+
+const getMediaInfoFromEvent = async (roomId, event_id) => {
+  const event = await matrix.utils.fetchEncryptedOrNot(roomId, { event_id });
+  if (event.getType() !== 'm.room.message') throw new Error('Invalid type');
+  const content = event.getContent();
+  if (content.msgtype !== 'm.image') throw new Error('Invalid msgtype');
+  if (content.url) return { url: getMediaUrl(content.url) };
+  if (content.file) return {
+    url: getMediaUrl(content.file.url),
+    filename: content.body,
+    mimetype: content.info ? content.info.mimetype : null,
+    file: content.file
+  };
+  throw new Error('Invalid event');
+};
+
+const getMediaUrl = string => {
+  let url = new URL(string);
+  if (url.protocol === 'mxc:' && url.hostname && url.pathname)
+    url = new URL(`${config.matrix.domain}/_matrix/media/r0/download/${url.hostname}${url.pathname}`);
+  if (url.protocol !== 'https:' ||
+     !config.matrix.domains.includes(url.hostname) ||
+     !mediaPathRegex.test(url.pathname))
+      throw new Error('Invalid URL');
+  return url.toString();
+};
+
+const getMedia = async (roomId, string) => {
+  let opts = {};
+  if (string.startsWith('mxe://'))
+    opts = await getMediaInfoFromEvent(roomId, string.substring(6));
+  else
+    opts.url = getMediaUrl(string);
+  const media = await mediaDownload(opts);
+  return opts.file ? decryptMedia(media, opts.file) : media;
+};
+
 const getFilename = (header) => {
   if (typeof header !== 'string') return null;
   try {
@@ -14,15 +66,14 @@ const getFilename = (header) => {
   }
 };
 
-const mediaDownload = async (url, { whitelist, blacklist }) => {
-  const media = await axios({ method: 'GET', url, responseType: 'arraybuffer' });
-  if (media.statusText !== 'OK' || blacklist.includes(media.headers['content-type'])) throw media;
-  if (whitelist.length && !whitelist.includes(media.headers['content-type'])) throw media;
-  return {
-    data: media.data,
-    filename: getFilename(media.headers['content-disposition']),
-    mimetype: media.headers['content-type'],
-  };
+const mediaDownload = async (opts) => {
+  const { whitelist, blacklist } = config.fediverse.mimetypes;
+  const media = await axios({ method: 'GET', url: opts.url, responseType: 'arraybuffer' });
+  const filename = opts.filename || getFilename(media.headers['content-disposition']);
+  const mimetype = opts.mimetype || media.headers['content-type'];
+  if (media.statusText !== 'OK' || blacklist.includes(mimetype)) throw media;
+  if (whitelist.length && !whitelist.includes(mimetype)) throw media;
+  return { data: media.data, filename, mimetype };
 };
 
 const mediaUpload = async ({ domain }, { data, filename, mimetype }) => {
@@ -41,10 +92,10 @@ const mediaUpload = async ({ domain }, { data, filename, mimetype }) => {
   return upload.data.id;
 };
 
-const run = async (roomId, event, content, replyId, mediaURL, subject) => {
+const run = async (roomId, event, content, replyId, mediaURL, subject, visibility) => {
   let mediaId = null;
   if (mediaURL) {
-    const media = await mediaDownload(mediaURL, config.fediverse.mimetypes);
+    const media = await getMedia(roomId, mediaURL);
     mediaId = await mediaUpload(config.fediverse, media);
   }
   if (replyId) content = await fediverse.utils.getStatusMentions(replyId, event).then(m => m.concat(content).join(' '));
@@ -55,6 +106,7 @@ const run = async (roomId, event, content, replyId, mediaURL, subject) => {
     data: qs.stringify({
       status: content,
       content_type: 'text/markdown',
+      visibility: visibility || undefined,
       media_ids: mediaURL && [mediaId] || undefined,
       in_reply_to_id: replyId || undefined,
       spoiler_text: subject || undefined,
@@ -63,28 +115,16 @@ const run = async (roomId, event, content, replyId, mediaURL, subject) => {
   return fediverse.utils.sendEventWithMeta(roomId, `<a href="${response.data.url}">${response.data.id}</a>`, `redact ${response.data.id}`);
 };
 
-exports.runQuery = async (roomId, event, userInput, { isReply, hasMedia, hasSubject }) => {
+exports.runQuery = async (roomId, event, userInput, { isReply, hasMedia, hasSubject, visibility }) => {
   try {
     const chunks = userInput.trim().split(' ');
     if (!chunks.length || chunks.length < !!isReply + !!hasMedia) throw '';
     let replyId = null;
     let mediaURL = null;
     const subject = hasSubject ? config.fediverse.subject : null;
-    if (isReply) {
-      replyId = chunks[0];
-      chunks.shift();
-    }
-    if (hasMedia) {
-      let url = new URL(chunks[0]);
-      chunks.shift();
-      if (url.protocol === 'mxc:' && url.hostname && url.pathname)
-        url = new URL(`${config.matrix.domain}/_matrix/media/r0/download/${url.hostname}${url.pathname}`);
-      if (url.protocol !== 'https:') throw '';
-      if (!config.matrix.domains.includes(url.hostname)) throw '';
-      if (!/^\/_matrix\/media\/r0\/download\/[^/]+\/[^/]+\/?$/.test(url.pathname)) throw '';
-      mediaURL = url.toString();
-    }
-    return await run(roomId, event, chunks.join(' '), replyId, mediaURL, subject);
+    if (isReply) replyId = chunks.shift();
+    if (hasMedia) mediaURL = chunks.shift();
+    return await run(roomId, event, chunks.join(' '), replyId, mediaURL, subject, visibility);
   } catch (e) {
     return matrixClient.sendHtmlNotice(roomId, 'Sad!', '<strong>Sad!</strong>').catch(() => {});
   }

commands/fediverse/unroll.js

@@ -7,17 +7,19 @@ exports.runQuery = function (roomId, event, userInput) {
   instance.get(`/api/v1/statuses/${userInput}/context`)
     .then(async (response) => {
       let story = [];
+      const rel = event.getContent()['m.relates_to'];
+      const eventId = rel && rel.event_id ? rel.event_id : event.getId();
       const original = await instance.get(`/api/v1/statuses/${userInput}`);
       const ancestors = response.data.ancestors;
       const descendants = response.data.descendants;
       story = [...story, ancestors, original.data, descendants];
       const book = story.flat();
-      await fediverse.utils.thread(roomId, event, '<br><hr><h3>...Beginning thread...</h3><hr><br>');
+      await fediverse.utils.thread(roomId, eventId, '<br><hr><h3>...Beginning thread...</h3><hr><br>');
       for (const [i, entry] of book.entries()) {
         entry.label = 'thread';
-        fediverse.utils.formatter(entry, roomId, event)
+        fediverse.utils.formatter(entry, roomId, eventId);
       }
-      await fediverse.utils.thread(roomId, event, '<br><hr><h3>...Thread ended...</h3><hr><br>');
+      await fediverse.utils.thread(roomId, eventId, '<br><hr><h3>...Thread ended...</h3><hr><br>');
     })
     .catch((e) => {
       matrix.utils.addReact(event, '❌');

commands/fediverse/utils.js

@@ -8,7 +8,7 @@ const sendEventWithMeta = async (roomId, content, meta) => {
   });
 };
 
-const thread = async (roomId, event, content, meta) => {
+const thread = async (roomId, eventId, content, meta) => {
   await matrixClient.sendEvent(roomId, 'm.room.message', {
     body: content.replace(/<[^<]+?>/g, ''),
     msgtype: 'm.notice',
@@ -17,7 +17,7 @@ const thread = async (roomId, event, content, meta) => {
     format: 'org.matrix.custom.html',
     'm.relates_to': {
       rel_type: 'm.thread',
-      event_id: event['event']['content']['m.relates_to']['event_id'],
+      event_id: eventId,
     },
   })
 };
@@ -78,6 +78,18 @@ const notifyFormatter = (res, roomId) => {
            </blockquote>`;
       sendEventWithMeta(roomId, content, meta);
       break;
+    case 'pleroma:emoji_reaction':
+        fediverse.auth.me !== res.account.url ? res.meta = 'react' : res.meta = 'redact';
+        meta = `${res.meta} ${res.status.id}`;
+        content = `${userDetails}
+         <font color="#03b381"><b>has <a href="${config.fediverse.domain}/notice/${res.status.id}">reacted</a> with
+         ${ res.emoji_url ? `<a href="${res.emoji_url}">${res.emoji}</a>` : `<span>${res.emoji}</span>` }
+         to your post:</font><blockquote><i>${res.status.content}</i><br>
+             ${hasAttachment(res)}
+             <br>(id: ${res.status.id}) ${registrar.post.visibilityEmoji(res.status.visibility)}
+             </blockquote>`;
+        sendEventWithMeta(roomId, content, meta);
+        break;
     default:
       return console.log('Unknown notification type.');
   }

commands/help.js

@@ -3,6 +3,8 @@ exports.runQuery = function (roomId) {
     ' ',
     '<blockquote><b>fediverse commands<br>'
           + '+post [your message] : post<br>'
+          + '+direct [@recipient] [message] : direct message<br>'
+          + '+private [message] : follower-only message<br>'
           + '+redact [post id] : delete post<br>'
           + '+follow [user id] : follow<br>'
           + '+unfollow [user id] : unfollow<br>'