2.0.0

Move timeouts to bot and use custom event to signal clients to close

README.md

@@ -11,7 +11,6 @@ BOT_USERNAME=
 BOT_PASSWORD=
 BOT_USERID=
 FACILITATOR_ROOM_ID=
-FACILITATOR_GROUP_ID=
 CHAT_OFFLINE_MESSAGE=
 CAPTURE_TRANSCRIPTS=
 ```

__mocks__/matrix-js-sdk.js

@@ -157,6 +157,10 @@ export const mockGetGroupUsers = jest.fn(() => {
 
 export const mockGetUser = jest.fn().mockReturnValue({ presence: 'online'});
 
+export const mockSendStateEvent = jest.fn(() => {
+  return Promise.resolve();
+});
+
 export const mockClient = {
   registerRequest: mockRegisterRequest,
   initCrypto: mockInitCrypto,
@@ -186,6 +190,7 @@ export const mockClient = {
   getJoinedRoomMembers: mockGetJoinedRoomMembers,
   getUser: mockGetUser,
   getGroupUsers: mockGetGroupUsers,
+  sendStateEvent: mockSendStateEvent,
 }
 
 export const WebStorageSessionStore = jest.fn()

dist/bot.js

@@ -23,13 +23,17 @@ var matrix = _interopRequireWildcard(require("matrix-js-sdk"));
 
 var _logger = _interopRequireDefault(require("./logger"));
 
+var _encryptAttachment = _interopRequireDefault(require("./encrypt-attachment"));
+
 global.Olm = require("olm");
+const BOT_SIGNAL_END_CHAT = 'END_CHAT';
 
 class OcrccBot {
   constructor(botConfig) {
     this.config = botConfig;
     this.client = matrix.createClient(this.config.MATRIX_SERVER_URL);
     this.joinedRooms = [];
+    this.inactivityTimers = {};
   }
 
   createLocalStorage() {
@@ -100,7 +104,7 @@ class OcrccBot {
           await this.sendMessage(roomId, content);
 
         default:
-          _logger.default.log("error", `ERROR SENDING MESSAGE: ${err}`);
+          _logger.default.log("error", `ERROR SENDING MESSAGE ${content.body}: ${err}`);
 
           break;
       }
@@ -185,10 +189,19 @@ class OcrccBot {
   }
 
   handleMessageEvent(event) {
-    const content = event.getContent(); // do nothing if there's no content
+    const content = event.getContent();
+    const sender = event.getSender();
+    const roomId = event.getRoomId(); // do nothing if there's no content
 
     if (!content) {
       return;
+    } // if it's a chat message and the facilitator has joined, reset the inactivity timeout
+
+
+    const facilitatorId = this.localStorage.getItem(`${roomId}-facilitator`);
+
+    if (Boolean(facilitatorId) && sender !== this.config.BOT_USERID) {
+      this.setInactivityTimeout(roomId);
     } // bot commands
 
 
@@ -225,35 +238,43 @@ class OcrccBot {
   }
 
   handleBotCommand(event) {
+    const botCommands = [{
+      keyword: 'transcript',
+      function: (senderId, roomId) => {
+        this.sendTranscript(senderId, roomId);
+      }
+    }, {
+      keyword: 'delete transcript',
+      function: (senderId, roomId) => {
+        this.deleteTranscript(senderId, roomId);
+      }
+    }, {
+      keyword: 'say',
+      function: (senderId, roomId, message) => {
+        this.sendTextMessage(roomId, message, senderId);
+      }
+    }, {
+      keyword: 'hi',
+      function: (senderId, roomId) => {
+        const responses = ["Hi!", "Hello", "Hey :)", "Hi there", "Bleep bloop"];
+        const message = responses[Math.floor(Math.random() * responses.length)];
+        this.sendTextMessage(roomId, message, senderId);
+      }
+    }];
+
     try {
       const senderId = event.getSender();
       const roomId = event.getRoomId();
       const content = event.getContent();
-      const command = content.body.substring("!bot".length).trim();
+      const commandText = content.body.substring("!bot".length).trim();
+      const command = botCommands.find(c => commandText.startsWith(c.keyword));
 
-      switch (command) {
+      if (!command) {
-        case "transcript":
+        this.sendTextMessage(roomId, `Sorry, I don't know that command. I'm not a very smart bot.`, senderId);
-          this.sendTranscript(senderId, roomId);
-          break;
-
-        case "transcript please":
-          this.sendTranscript(senderId, roomId);
-          break;
-
-        case "delete transcript":
-          this.deleteTranscript(senderId, roomId);
-          break;
-
-        case "hi":
-          const responses = ["Hi!", "Hello", "Hey :)", "Hi there", "Bleep bloop"];
-          const message = responses[Math.floor(Math.random() * responses.length)];
-          this.sendTextMessage(roomId, message, senderId);
-          break;
-
-        default:
-          this.sendTextMessage(roomId, `Sorry, I don't know that command. I'm not a very smart bot.`, senderId);
-          break;
       }
+
+      const args = commandText.substring(command.keyword.length).trim();
+      command.function(senderId, roomId, args);
     } catch (err) {
       _logger.default.log("error", `ERROR EXECUTING BOT COMMAND: ${err}`);
     }
@@ -289,28 +310,55 @@ class OcrccBot {
         this.sendTextMessage(roomId, "There is no transcript for this chat.", senderId);
       }
 
-      const filename = path.basename(transcriptFile) || "Transcript";
+      if (this.client.isRoomEncrypted(roomId)) {
-      const file = fs.readFileSync(transcriptFile);
+        let encryptInfo;
-      const stats = fs.statSync(transcriptFile);
+        const filename = path.basename(transcriptFile) || "Transcript";
-      const url = await this.client.uploadContent(file, {
+        const data = fs.readFileSync(transcriptFile);
-        rawResponse: false,
+        const encryptResult = await _encryptAttachment.default.encryptAttachment(data);
-        name: filename
+        const buffer = Buffer.from(encryptResult.data);
-      });
+        encryptInfo = encryptResult.info;
-
+        const url = await this.client.uploadContent(buffer, {
-      _logger.default.log('info', url);
+          rawResponse: false,
-
+          name: filename
-      const content = {
+        });
-        msgtype: "m.file",
+        encryptInfo.url = url.content_uri;
-        body: filename,
+        encryptInfo.mimetype = 'text/plain';
-        info: {
+        const content = {
-          size: stats.size,
+          msgtype: "m.file",
+          body: filename,
+          info: {
+            mimetype: 'text/plain'
+          },
+          file: encryptInfo,
+          url: url.content_uri,
+          showToUser: senderId,
           mimetype: 'text/plain'
-        },
+        };
-        url: url.content_uri,
+        this.sendMessage(roomId, content);
-        showToUser: senderId,
+      } else {
-        mimetype: 'text/plain'
+        const filename = path.basename(transcriptFile) || "Transcript";
-      };
+        const file = fs.readFileSync(transcriptFile);
-      this.sendMessage(roomId, content);
+        const stats = fs.statSync(transcriptFile);
+        const url = await this.client.uploadContent(file, {
+          rawResponse: false,
+          name: filename
+        });
+
+        _logger.default.log('info', url);
+
+        const content = {
+          msgtype: "m.file",
+          body: filename,
+          info: {
+            size: stats.size,
+            mimetype: 'text/plain'
+          },
+          url: url.content_uri,
+          showToUser: senderId,
+          mimetype: 'text/plain'
+        };
+        this.sendMessage(roomId, content);
+      }
     } catch (err) {
       _logger.default.log("error", `ERROR UPLOADING CONTENT: ${err}`);
 
@@ -389,13 +437,14 @@ class OcrccBot {
 
             _logger.default.log("info", "AUTO JOINED ROOM => " + room.roomId);
 
-            const currentDate = new Date();
+            const inviteDate = event.getDate();
-            const chatDate = currentDate.toLocaleDateString();
+            const chatDate = inviteDate.toLocaleDateString();
-            const chatTime = currentDate.toLocaleTimeString();
+            const chatTime = inviteDate.toLocaleTimeString();
             const roomId = room.roomId.split(':')[0];
             const notification = `Incoming support chat at ${chatTime} (room ID: ${roomId})`;
             this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification);
             this.inviteFacilitators(room.roomId);
+            this.setTimeoutforFacilitator(room.roomId);
           }
         } catch (err) {
           _logger.default.log("error", "ERROR JOINING ROOM => " + err);
@@ -403,82 +452,141 @@ class OcrccBot {
       }
 
       if (member.membership === "join" && member.userId !== this.config.BOT_USERID && this.localStorage.getItem(`${member.roomId}-waiting`)) {
-        // make sure it's a facilitator joining
+        try {
-        const roomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID);
+          // make sure it's a facilitator joining
-        const members = Object.keys(roomMembers["joined"]);
+          const roomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID);
-        const isFacilitator = members.includes(member.userId);
+          const members = Object.keys(roomMembers["joined"]);
+          const isFacilitator = members.includes(member.userId);
 
-        if (isFacilitator) {
+          if (isFacilitator) {
-          // made facilitator a moderator in the room
+            // made facilitator a moderator in the room
-          this.localStorage.setItem(`${member.roomId}-facilitator`, member.userId);
+            this.localStorage.setItem(`${member.roomId}-facilitator`, member.userId);
-          const event = {
+            const event = {
-            getType: () => {
+              getType: () => {
-              return "m.room.power_levels";
+                return "m.room.power_levels";
-            },
+              },
-            getContent: () => {
+              getContent: () => {
-              return {
+                return {
-                users: {
+                  users: {
-                  [this.config.BOT_USERID]: 100,
+                    [this.config.BOT_USERID]: 100,
-                  [member.userId]: 50
+                    [member.userId]: 50
-                }
+                  }
-              };
+                };
-            }
+              }
-          };
-          this.client.setPowerLevel(member.roomId, member.userId, 50, event); // send notification to Support Chat Notifications room
-
-          const currentDate = new Date();
-          const chatTime = currentDate.toLocaleTimeString();
-          const roomId = member.roomId.split(':')[0];
-          const notification = `${member.name} joined the chat at ${chatTime} (room ID: ${roomId})`;
-          this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification); // send notification to chat room
-
-          this.sendTextMessage(member.roomId, `${member.name} has joined the chat.`); // revoke the other invitations
-
-          this.uninviteFacilitators(member.roomId); // set transcript file
-
-          if (this.config.CAPTURE_TRANSCRIPTS) {
-            const currentDate = new Date();
-            const dateOpts = {
-              year: "numeric",
-              month: "short",
-              day: "numeric"
             };
-            const chatDate = currentDate.toLocaleDateString("en-GB", dateOpts);
+            this.client.setPowerLevel(member.roomId, member.userId, 50, event); // send notification to Support Chat Notifications room
-            const chatTime = currentDate.toLocaleTimeString("en-GB", {
+
-              timeZone: "America/New_York"
+            const currentDate = new Date();
-            });
+            const chatTime = currentDate.toLocaleTimeString();
-            const filename = `${chatDate} - ${chatTime} - ${member.roomId}.txt`;
+            const roomId = member.roomId.split(':')[0];
-            const filepath = path.resolve(path.join("transcripts", filename));
+            const notification = `${member.name} joined the chat at ${chatTime} (room ID: ${roomId})`;
-            this.localStorage.setItem(`${member.roomId}-transcript`, filepath);
+            this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification); // send notification to chat room
+
+            this.sendTextMessage(member.roomId, `${member.name} has joined the chat.`); // revoke the other invitations
+
+            this.uninviteFacilitators(member.roomId); // set transcript file
+
+            if (this.config.CAPTURE_TRANSCRIPTS) {
+              const currentDate = new Date();
+              const dateOpts = {
+                year: "numeric",
+                month: "short",
+                day: "numeric"
+              };
+              const chatDate = currentDate.toLocaleDateString("en-GB", dateOpts);
+              const chatTime = currentDate.toLocaleTimeString("en-GB", {
+                timeZone: "America/New_York"
+              });
+              const filename = `${chatDate} - ${chatTime} - ${member.roomId}.txt`;
+              const filepath = path.resolve(path.join("transcripts", filename));
+              this.localStorage.setItem(`${member.roomId}-transcript`, filepath);
+            }
           }
+        } catch (err) {
+          _logger.default.log("error", `ERROR WHEN FACILITATOR JOINED ROOM ==> ${err}`);
         }
       }
 
       if (member.membership === "leave" && member.userId !== this.config.BOT_USERID) {
-        const facilitatorId = this.localStorage.getItem(`${member.roomId}-facilitator`);
+        const room = this.client.getRoom(member.roomId);
+        if (!room) return;
+        const roomMembers = await room.getJoinedMembers(); // array
 
-        if (member.userId === facilitatorId) {
+        const facilitatorRoomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID); // object
-          this.sendTextMessage(member.roomId, `${member.name} has left the chat.`);
+
+        const isBotInRoom = roomMembers.find(member => member.userId === this.config.BOT_USERID); // notify room if the facilitator has left
+
+        try {
+          const facilitatorId = this.localStorage.getItem(`${member.roomId}-facilitator`);
+
+          if (isBotInRoom && member.userId === facilitatorId) {
+            this.sendTextMessage(member.roomId, `${member.name} has left the chat.`);
+          }
+        } catch (err) {
+          _logger.default.log("error", `ERROR NOTIFYING THAT FACLITATOR HAS LEFT THE ROOM ==> ${err}`);
         } // leave if there is nobody in the room
 
 
-        const room = this.client.getRoom(member.roomId);
+        try {
-        if (!room) return;
+          const memberCount = roomMembers.length;
-        const memberCount = room.getJoinedMemberCount();
 
-        if (memberCount === 1) {
+          if (memberCount === 1 && isBotInRoom) {
-          // just the bot left
+            // just the bot left
-          _logger.default.log("info", `LEAVING EMPTY ROOM ==> ${member.roomId}`);
+            _logger.default.log("info", `LEAVING EMPTY ROOM ==> ${member.roomId}`);
 
-          this.deleteTranscript(member.userId, member.roomId);
+            this.deleteTranscript(member.userId, member.roomId);
-          this.localStorage.removeItem(`${member.roomId}-facilitator`);
+            this.localStorage.removeItem(`${member.roomId}-facilitator`);
-          this.localStorage.removeItem(`${member.roomId}-transcript`);
+            this.localStorage.removeItem(`${member.roomId}-transcript`);
-          this.client.leave(member.roomId);
+            return this.client.leave(member.roomId);
+          }
+        } catch (err) {
+          _logger.default.log("error", `ERROR LEAVING EMPTY ROOM ==> ${err}`);
+        } // send signal to close the chat if there are no facilitators in the room
+
+
+        try {
+          const facilitators = facilitatorRoomMembers['joined'];
+          let facilitatorInRoom = false;
+          roomMembers.forEach(member => {
+            if (member.userId !== this.config.BOT_USERID && Boolean(facilitators[member.userId])) {
+              facilitatorInRoom = true;
+            }
+          });
+
+          if (!facilitatorInRoom) {
+            this.sendBotSignal(member.roomId, BOT_SIGNAL_END_CHAT);
+          }
+        } catch (err) {
+          _logger.default.log("error", `ERROR SENDING BOT SIGNAL ==> ${err}`);
         }
       }
     });
   }
 
+  setTimeoutforFacilitator(roomId) {
+    setTimeout(() => {
+      const stillWaiting = this.localStorage.getItem(`${roomId}-waiting`);
+
+      if (stillWaiting) {
+        this.sendBotSignal(roomId, BOT_SIGNAL_END_CHAT);
+      }
+    }, this.config.MAX_WAIT_TIME);
+  }
+
+  setInactivityTimeout(roomId) {
+    const oldTimeout = this.inactivityTimers[roomId];
+
+    if (oldTimeout) {
+      clearTimeout(oldTimeout);
+    }
+
+    const newTimeout = setTimeout(() => {
+      this.sendTextMessage(roomId, `This chat has been closed due to inactivity.`);
+      this.sendBotSignal(roomId, BOT_SIGNAL_END_CHAT);
+    }, this.config.MAX_INACTIVE);
+    this.inactivityTimers[roomId] = newTimeout;
+  }
+
   async setMessageListeners() {
     // encrypted messages
     this.client.on("Event.decrypted", (event, err) => {
@@ -509,6 +617,19 @@ class OcrccBot {
     });
   }
 
+  async sendBotSignal(roomId, signal, args) {
+    let content = {
+      signal: signal,
+      args: args
+    };
+
+    try {
+      await this.client.sendStateEvent(roomId, 'm.bot.signal', content);
+    } catch (err) {
+      _logger.default.log('error', "ERROR SENDING BOT SIGNAL => " + err);
+    }
+  }
+
   async start() {
     const localStorage = this.createLocalStorage();
     this.localStorage = localStorage;
@@ -531,14 +652,20 @@ class OcrccBot {
         sessionStore: new matrix.WebStorageSessionStore(localStorage)
       };
       this.client = matrix.createClient(opts);
-      await this.deleteOldDevices();
-      await this.trackJoinedRooms();
       await this.client.initCrypto();
-      await this.setMembershipListeners();
-      await this.setMessageListeners();
       this.client.startClient({
         initialSyncLimit: 0
       });
+      this.client.once('sync', async (state, prevState, data) => {
+        _logger.default.log("info", `SYNC STATUS: ${state}`);
+
+        if (state === 'PREPARED') {
+          await this.deleteOldDevices();
+          await this.trackJoinedRooms();
+          await this.setMembershipListeners();
+          await this.setMessageListeners();
+        }
+      });
     } catch (err) {
       this.handleBotCrash(undefined, err);
 

dist/bot.test.js

@@ -103,6 +103,8 @@ describe('OcrccBot', () => {
     mockAppendFileSync.mockClear();
 
     _matrixJsSdk.mockGetGroupUsers.mockClear();
+
+    _matrixJsSdk.mockSendStateEvent.mockClear();
   });
   test('constructor should inititialize class variables', () => {
     const bot = new _bot.default(botConfig);
@@ -276,4 +278,16 @@ describe('OcrccBot', () => {
       expect(_matrixJsSdk.mockStartClient).toHaveBeenCalled();
     });
   });
+  test('#sendBotSignal should send custom state event', () => {
+    const bot = new _bot.default(botConfig);
+    bot.start();
+    const test_room_id = 'test_room_id';
+    const signal = 'END_CHAT';
+    bot.sendBotSignal(test_room_id, signal);
+    (0, _waitForExpect.default)(() => {
+      expect(_matrixJsSdk.mockSendStateEvent).toHaveBeenCalledWith(test_room_id, 'm.bot.signal', {
+        signal
+      });
+    });
+  });
 });

dist/encrypt-attachment.js

@@ -0,0 +1,173 @@
+"use strict";
+
+// this is from https://github.com/matrix-org/browser-encrypt-attachment
+// which is the library used by matrix-reack-sdk to encrypt and decrypt attachments
+// just dropped in node-webcrypto-ossl to replace window.crypto
+// and Buffer for base64 encoding/decoding instead of window.btoa/window.atob
+
+/**
+ * Encrypt an attachment.
+ * @param {ArrayBuffer} plaintextBuffer The attachment data buffer.
+ * @return {Promise} A promise that resolves with an object when the attachment is encrypted.
+ *      The object has a "data" key with an ArrayBuffer of encrypted data and an "info" key
+ *      with an object containing the info needed to decrypt the data.
+ */
+const {
+  Crypto
+} = require("node-webcrypto-ossl");
+
+const crypto = new Crypto();
+
+function encryptAttachment(plaintextBuffer) {
+  var cryptoKey; // The AES key object.
+
+  var exportedKey; // The AES key exported as JWK.
+
+  var ciphertextBuffer; // ArrayBuffer of encrypted data.
+
+  var sha256Buffer; // ArrayBuffer of digest.
+
+  var ivArray; // Uint8Array of AES IV
+  // Generate an IV where the first 8 bytes are random and the high 8 bytes
+  // are zero. We set the counter low bits to 0 since it makes it unlikely
+  // that the 64 bit counter will overflow.
+
+  ivArray = new Uint8Array(16);
+  crypto.getRandomValues(ivArray.subarray(0, 8)); // Load the encryption key.
+
+  return crypto.subtle.generateKey({
+    "name": "AES-CTR",
+    length: 256
+  }, true, ["encrypt", "decrypt"]).then(function (generateKeyResult) {
+    cryptoKey = generateKeyResult; // Export the Key as JWK.
+
+    return crypto.subtle.exportKey("jwk", cryptoKey);
+  }).then(function (exportKeyResult) {
+    exportedKey = exportKeyResult; // Encrypt the input ArrayBuffer.
+    // Use half of the iv as the counter by setting the "length" to 64.
+
+    return crypto.subtle.encrypt({
+      name: "AES-CTR",
+      counter: ivArray,
+      length: 64
+    }, cryptoKey, plaintextBuffer);
+  }).then(function (encryptResult) {
+    ciphertextBuffer = encryptResult; // SHA-256 the encrypted data.
+
+    return crypto.subtle.digest("SHA-256", ciphertextBuffer);
+  }).then(function (digestResult) {
+    sha256Buffer = digestResult;
+    return {
+      data: ciphertextBuffer,
+      info: {
+        v: "v2",
+        key: exportedKey,
+        iv: encodeBase64(ivArray),
+        hashes: {
+          sha256: encodeBase64(new Uint8Array(sha256Buffer))
+        }
+      }
+    };
+  });
+}
+/**
+ * Decrypt an attachment.
+ * @param {ArrayBuffer} ciphertextBuffer The encrypted attachment data buffer.
+ * @param {Object} info The information needed to decrypt the attachment.
+ * @param {Object} info.key AES-CTR JWK key object.
+ * @param {string} info.iv Base64 encoded 16 byte AES-CTR IV.
+ * @param {string} info.hashes.sha256 Base64 encoded SHA-256 hash of the ciphertext.
+ * @return {Promise} A promise that resolves with an ArrayBuffer when the attachment is decrypted.
+ */
+
+
+function decryptAttachment(ciphertextBuffer, info) {
+  if (info === undefined || info.key === undefined || info.iv === undefined || info.hashes === undefined || info.hashes.sha256 === undefined) {
+    throw new Error("Invalid info. Missing info.key, info.iv or info.hashes.sha256 key");
+  }
+
+  var cryptoKey; // The AES key object.
+
+  var ivArray = decodeBase64(info.iv);
+  var expectedSha256base64 = info.hashes.sha256; // Load the AES from the "key" key of the info object.
+
+  return crypto.subtle.importKey("jwk", info.key, {
+    "name": "AES-CTR"
+  }, false, ["encrypt", "decrypt"]).then(function (importKeyResult) {
+    cryptoKey = importKeyResult; // Check the sha256 hash
+
+    return crypto.subtle.digest("SHA-256", ciphertextBuffer);
+  }).then(function (digestResult) {
+    if (encodeBase64(new Uint8Array(digestResult)) != expectedSha256base64) {
+      throw new Error("Mismatched SHA-256 digest");
+    }
+
+    var counterLength;
+
+    if (info.v == "v1" || info.v == "v2") {
+      // Version 1 and 2 use a 64 bit counter.
+      counterLength = 64;
+    } else {
+      // Version 0 uses a 128 bit counter.
+      counterLength = 128;
+    }
+
+    return crypto.subtle.decrypt({
+      name: "AES-CTR",
+      counter: ivArray,
+      length: counterLength
+    }, cryptoKey, ciphertextBuffer);
+  });
+}
+/**
+ * Encode a typed array of uint8 as base64.
+ * @param {Uint8Array} uint8Array The data to encode.
+ * @return {string} The base64 without padding.
+ */
+
+
+function encodeBase64(uint8Array) {
+  // Misinterpt the Uint8Array as Latin-1.
+  // window.btoa expects a unicode string with codepoints in the range 0-255.
+  var latin1String = String.fromCharCode.apply(null, uint8Array); // Use the builtin base64 encoder.
+  // var paddedBase64 = window.btoa(latin1String);
+
+  var paddedBase64 = Buffer.from(latin1String, 'binary').toString('base64'); // Calculate the unpadded length.
+
+  var inputLength = uint8Array.length;
+  var outputLength = 4 * Math.floor((inputLength + 2) / 3) + (inputLength + 2) % 3 - 2; // Return the unpadded base64.
+
+  return paddedBase64.slice(0, outputLength);
+}
+/**
+ * Decode a base64 string to a typed array of uint8.
+ * This will decode unpadded base64, but will also accept base64 with padding.
+ * @param {string} base64 The unpadded base64 to decode.
+ * @return {Uint8Array} The decoded data.
+ */
+
+
+function decodeBase64(base64) {
+  // Pad the base64 up to the next multiple of 4.
+  var paddedBase64 = base64 + "===".slice(0, (4 - base64.length % 4) % 4); // Decode the base64 as a misinterpreted Latin-1 string.
+  // window.atob returns a unicode string with codepoints in the range 0-255.
+  // var latin1String = window.atob(paddedBase64);
+
+  var latin1String = Buffer.from(paddedBase64, 'base64').toString('binary'); // Encode the string as a Uint8Array as Latin-1.
+
+  var uint8Array = new Uint8Array(latin1String.length);
+
+  for (var i = 0; i < latin1String.length; i++) {
+    uint8Array[i] = latin1String.charCodeAt(i);
+  }
+
+  return uint8Array;
+}
+
+try {
+  exports.encryptAttachment = encryptAttachment;
+  exports.decryptAttachment = decryptAttachment;
+} catch (e) {// Ignore unknown variable "exports" errors when this is loaded directly into a browser
+  // This means that we can test it without having to use browserify.
+  // The intention is that the library is used using browserify.
+}

dist/index.js

@@ -19,7 +19,10 @@ const {
   BOT_PASSWORD,
   BOT_DISPLAY_NAME,
   FACILITATOR_ROOM_ID,
-  CAPTURE_TRANSCRIPTS
+  CAPTURE_TRANSCRIPTS,
+  CHAT_NOT_AVAILABLE_MESSAGE,
+  MAX_WAIT_TIME,
+  MAX_INACTIVE
 } = process.env;
 const botConfig = {
   ENCRYPTION_CONFIG,
@@ -32,7 +35,10 @@ const botConfig = {
   BOT_PASSWORD,
   BOT_DISPLAY_NAME,
   FACILITATOR_ROOM_ID,
-  CAPTURE_TRANSCRIPTS
+  CAPTURE_TRANSCRIPTS,
+  CHAT_NOT_AVAILABLE_MESSAGE,
+  MAX_WAIT_TIME,
+  MAX_INACTIVE
 };
 const bot = new _bot.default(botConfig);
 bot.start();

package.json

@@ -1,6 +1,6 @@
 {
   "name": "private-safesupport-bot",
-  "version": "1.1.4",
+  "version": "2.0.0",
   "description": "Chatbot to manage interactions on Safe Support Chat",
   "main": "dist/index.js",
   "scripts": {
@@ -15,6 +15,7 @@
     "dotenv": "^8.2.0",
     "matrix-js-sdk": "^6.2.1",
     "node-localstorage": "^2.1.5",
+    "node-webcrypto-ossl": "^2.1.0",
     "olm": "https://packages.matrix.org/npm/olm/olm-3.1.4.tgz",
     "uuidv4": "^6.0.2",
     "winston": "^3.2.1"

src/bot.js

@@ -9,6 +9,9 @@ global.Olm = require("olm");
 import * as matrix from "matrix-js-sdk";
 
 import logger from "./logger";
+import encrypt from "./encrypt-attachment";
+
+const BOT_SIGNAL_END_CHAT = 'END_CHAT'
 
 
 class OcrccBot {
@@ -16,6 +19,7 @@ class OcrccBot {
     this.config = botConfig
     this.client = matrix.createClient(this.config.MATRIX_SERVER_URL);
     this.joinedRooms = [];
+    this.inactivityTimers = {};
   }
 
   createLocalStorage() {
@@ -81,7 +85,7 @@ class OcrccBot {
           });
           await this.sendMessage(roomId, content);
         default:
-          logger.log("error", `ERROR SENDING MESSAGE: ${err}`);
+          logger.log("error", `ERROR SENDING MESSAGE ${content.body}: ${err}`);
           break;
       }
     }
@@ -175,12 +179,20 @@ class OcrccBot {
 
   handleMessageEvent(event) {
     const content = event.getContent();
+    const sender = event.getSender()
+    const roomId = event.getRoomId();
 
     // do nothing if there's no content
     if (!content) {
       return;
     }
 
+    // if it's a chat message and the facilitator has joined, reset the inactivity timeout
+    const facilitatorId = this.localStorage.getItem(`${roomId}-facilitator`)
+    if (Boolean(facilitatorId) && sender !== this.config.BOT_USERID) {
+      this.setInactivityTimeout(roomId)
+    }
+
     // bot commands
     if (content.body.startsWith("!bot")) {
       return this.handleBotCommand(event);
@@ -216,23 +228,24 @@ class OcrccBot {
   }
 
   handleBotCommand(event) {
-    try {
+    const botCommands = [
-      const senderId = event.getSender();
+      {
-      const roomId = event.getRoomId();
+        keyword: 'transcript',
-      const content = event.getContent();
+        function: (senderId, roomId) => { this.sendTranscript(senderId, roomId) }
-      const command = content.body.substring("!bot".length).trim();
+      },
-
+      {
-      switch (command) {
+        keyword: 'delete transcript',
-        case "transcript":
+        function: (senderId, roomId) => { this.deleteTranscript(senderId, roomId) }
-          this.sendTranscript(senderId, roomId);
+      },
-          break;
+      {
-        case "transcript please":
+        keyword: 'say',
-          this.sendTranscript(senderId, roomId);
+        function: (senderId, roomId, message) => {
-          break;
+          this.sendTextMessage(roomId, message, senderId);
-        case "delete transcript":
+        }
-          this.deleteTranscript(senderId, roomId);
+      },
-          break;
+      {
-        case "hi":
+        keyword: 'hi',
+        function: (senderId, roomId) => {
           const responses = [
             "Hi!",
             "Hello",
@@ -240,18 +253,28 @@ class OcrccBot {
             "Hi there",
             "Bleep bloop"
           ];
-          const message =
+          const message = responses[Math.floor(Math.random() * responses.length)];
-            responses[Math.floor(Math.random() * responses.length)];
           this.sendTextMessage(roomId, message, senderId);
-          break;
+        }
-        default:
-          this.sendTextMessage(
-            roomId,
-            `Sorry, I don't know that command. I'm not a very smart bot.`,
-            senderId
-          );
-          break;
       }
+    ]
+    try {
+      const senderId = event.getSender();
+      const roomId = event.getRoomId();
+      const content = event.getContent();
+      const commandText = content.body.substring("!bot".length).trim();
+      const command = botCommands.find(c => commandText.startsWith(c.keyword))
+
+      if (!command) {
+        this.sendTextMessage(
+          roomId,
+          `Sorry, I don't know that command. I'm not a very smart bot.`,
+          senderId
+        );
+      }
+
+      const args = commandText.substring(command.keyword.length).trim()
+      command.function(senderId, roomId, args)
     } catch (err) {
       logger.log("error", `ERROR EXECUTING BOT COMMAND: ${err}`);
     }
@@ -289,26 +312,54 @@ class OcrccBot {
         );
       }
 
-      const filename = path.basename(transcriptFile) || "Transcript";
+      if (this.client.isRoomEncrypted(roomId)) {
-      const file = fs.readFileSync(transcriptFile);
+        let encryptInfo;
-      const stats = fs.statSync(transcriptFile);
+        const filename = path.basename(transcriptFile) || "Transcript";
+        const data = fs.readFileSync(transcriptFile);
+        const encryptResult = await encrypt.encryptAttachment(data)
+        const buffer = Buffer.from(encryptResult.data)
+        encryptInfo = encryptResult.info;
+        const url = await this.client.uploadContent(buffer, { rawResponse: false, name: filename })
+        encryptInfo.url = url.content_uri;
+        encryptInfo.mimetype = 'text/plain'
 
-      const url = await this.client.uploadContent(file, { rawResponse: false, name: filename })
+        const content = {
-      logger.log('info', url)
+          msgtype: "m.file",
-
+          body: filename,
-      const content = {
+          info: {
-        msgtype: "m.file",
+            mimetype: 'text/plain'
-        body: filename,
+          },
-        info: {
+          file: encryptInfo,
-          size: stats.size,
+          url: url.content_uri,
+          showToUser: senderId,
           mimetype: 'text/plain'
-        },
+        };
-        url: url.content_uri,
+
-        showToUser: senderId,
+        this.sendMessage(roomId, content);
-        mimetype: 'text/plain'
+
-      };
+      } else {
+        const filename = path.basename(transcriptFile) || "Transcript";
+        const file = fs.readFileSync(transcriptFile);
+        const stats = fs.statSync(transcriptFile);
+
+        const url = await this.client.uploadContent(file, { rawResponse: false, name: filename })
+        logger.log('info', url)
+
+        const content = {
+          msgtype: "m.file",
+          body: filename,
+          info: {
+            size: stats.size,
+            mimetype: 'text/plain'
+          },
+          url: url.content_uri,
+          showToUser: senderId,
+          mimetype: 'text/plain'
+        };
+
+        this.sendMessage(roomId, content);
+      }
 
-      this.sendMessage(roomId, content);
     } catch(err) {
       logger.log("error", `ERROR UPLOADING CONTENT: ${err}`);
       this.sendTextMessage(
@@ -394,13 +445,14 @@ class OcrccBot {
           if (!joinedRooms.includes(member.roomId)) {
             const room = await this.client.joinRoom(member.roomId)
             logger.log("info", "AUTO JOINED ROOM => " + room.roomId)
-            const currentDate = new Date()
+            const inviteDate = event.getDate()
-            const chatDate = currentDate.toLocaleDateString()
+            const chatDate = inviteDate.toLocaleDateString()
-            const chatTime = currentDate.toLocaleTimeString()
+            const chatTime = inviteDate.toLocaleTimeString()
             const roomId = room.roomId.split(':')[0]
             const notification = `Incoming support chat at ${chatTime} (room ID: ${roomId})`
             this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification);
             this.inviteFacilitators(room.roomId)
+            this.setTimeoutforFacilitator(room.roomId)
           }
         } catch(err) {
           logger.log("error", "ERROR JOINING ROOM => " + err)
@@ -412,61 +464,65 @@ class OcrccBot {
         member.userId !== this.config.BOT_USERID &&
         this.localStorage.getItem(`${member.roomId}-waiting`)
       ) {
-        // make sure it's a facilitator joining
+        try {
-        const roomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID)
+          // make sure it's a facilitator joining
-        const members = Object.keys(roomMembers["joined"]);
+          const roomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID)
-        const isFacilitator = members.includes(member.userId)
+          const members = Object.keys(roomMembers["joined"]);
+          const isFacilitator = members.includes(member.userId)
 
-        if (isFacilitator) {
+          if (isFacilitator) {
-          // made facilitator a moderator in the room
+            // made facilitator a moderator in the room
-          this.localStorage.setItem(`${member.roomId}-facilitator`, member.userId)
+            this.localStorage.setItem(`${member.roomId}-facilitator`, member.userId)
-          const event = {
+            const event = {
-            getType: () => {
+              getType: () => {
-              return "m.room.power_levels";
+                return "m.room.power_levels";
-            },
+              },
-            getContent: () => {
+              getContent: () => {
-              return {
+                return {
-                users: {
+                  users: {
-                  [this.config.BOT_USERID]: 100,
+                    [this.config.BOT_USERID]: 100,
-                  [member.userId]: 50
+                    [member.userId]: 50
-                }
+                  }
-              };
+                };
-            }
+              }
-          };
-          this.client.setPowerLevel(member.roomId, member.userId, 50, event);
-
-          // send notification to Support Chat Notifications room
-          const currentDate = new Date()
-          const chatTime = currentDate.toLocaleTimeString()
-          const roomId = member.roomId.split(':')[0]
-          const notification = `${member.name} joined the chat at ${chatTime} (room ID: ${roomId})`
-          this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification);
-
-          // send notification to chat room
-          this.sendTextMessage(
-            member.roomId,
-            `${member.name} has joined the chat.`
-          );
-
-          // revoke the other invitations
-          this.uninviteFacilitators(member.roomId);
-
-          // set transcript file
-          if (this.config.CAPTURE_TRANSCRIPTS) {
-            const currentDate = new Date();
-            const dateOpts = {
-              year: "numeric",
-              month: "short",
-              day: "numeric"
             };
-            const chatDate = currentDate.toLocaleDateString("en-GB", dateOpts);
+            this.client.setPowerLevel(member.roomId, member.userId, 50, event);
-            const chatTime = currentDate.toLocaleTimeString("en-GB", {
+
-              timeZone: "America/New_York"
+            // send notification to Support Chat Notifications room
-            });
+            const currentDate = new Date()
-            const filename = `${chatDate} - ${chatTime} - ${member.roomId}.txt`;
+            const chatTime = currentDate.toLocaleTimeString()
-            const filepath = path.resolve(path.join("transcripts", filename));
+            const roomId = member.roomId.split(':')[0]
-            this.localStorage.setItem(`${member.roomId}-transcript`, filepath)
+            const notification = `${member.name} joined the chat at ${chatTime} (room ID: ${roomId})`
+            this.sendTextMessage(this.config.FACILITATOR_ROOM_ID, notification);
+
+            // send notification to chat room
+            this.sendTextMessage(
+              member.roomId,
+              `${member.name} has joined the chat.`
+            );
+
+            // revoke the other invitations
+            this.uninviteFacilitators(member.roomId);
+
+            // set transcript file
+            if (this.config.CAPTURE_TRANSCRIPTS) {
+              const currentDate = new Date();
+              const dateOpts = {
+                year: "numeric",
+                month: "short",
+                day: "numeric"
+              };
+              const chatDate = currentDate.toLocaleDateString("en-GB", dateOpts);
+              const chatTime = currentDate.toLocaleTimeString("en-GB", {
+                timeZone: "America/New_York"
+              });
+              const filename = `${chatDate} - ${chatTime} - ${member.roomId}.txt`;
+              const filepath = path.resolve(path.join("transcripts", filename));
+              this.localStorage.setItem(`${member.roomId}-transcript`, filepath)
+            }
           }
+        } catch(err) {
+          logger.log("error", `ERROR WHEN FACILITATOR JOINED ROOM ==> ${err}`);
         }
       }
 
@@ -474,31 +530,89 @@ class OcrccBot {
         member.membership === "leave" &&
         member.userId !== this.config.BOT_USERID
       ) {
-        const facilitatorId = this.localStorage.getItem(`${member.roomId}-facilitator`)
+        const room = this.client.getRoom(member.roomId)
-        if (member.userId === facilitatorId) {
+        if (!room) return;
-          this.sendTextMessage(
+
-            member.roomId,
+        const roomMembers = await room.getJoinedMembers() // array
-            `${member.name} has left the chat.`
+        const facilitatorRoomMembers = await this.client.getJoinedRoomMembers(this.config.FACILITATOR_ROOM_ID) // object
-          );
+        const isBotInRoom = roomMembers.find(member => member.userId === this.config.BOT_USERID)
+
+        // notify room if the facilitator has left
+        try {
+          const facilitatorId = this.localStorage.getItem(`${member.roomId}-facilitator`)
+          if (isBotInRoom && member.userId === facilitatorId) {
+            this.sendTextMessage(
+              member.roomId,
+              `${member.name} has left the chat.`
+            );
+          }
+        } catch(err) {
+          logger.log("error", `ERROR NOTIFYING THAT FACLITATOR HAS LEFT THE ROOM ==> ${err}`);
         }
 
         // leave if there is nobody in the room
-        const room = this.client.getRoom(member.roomId)
+        try {
-        if (!room) return
+          const memberCount = roomMembers.length
+          if (memberCount === 1 && isBotInRoom) { // just the bot left
+            logger.log("info", `LEAVING EMPTY ROOM ==> ${member.roomId}`);
+            this.deleteTranscript(member.userId, member.roomId);
+            this.localStorage.removeItem(`${member.roomId}-facilitator`)
+            this.localStorage.removeItem(`${member.roomId}-transcript`)
+            return this.client.leave(member.roomId)
+          }
+        } catch(err) {
+          logger.log("error", `ERROR LEAVING EMPTY ROOM ==> ${err}`);
+        }
 
-        const memberCount = room.getJoinedMemberCount()
+        // send signal to close the chat if there are no facilitators in the room
+        try {
+          const facilitators = facilitatorRoomMembers['joined']
+          let facilitatorInRoom = false;
 
-        if (memberCount === 1) { // just the bot left
+          roomMembers.forEach(member => {
-          logger.log("info", `LEAVING EMPTY ROOM ==> ${member.roomId}`);
+            if (member.userId !== this.config.BOT_USERID && Boolean(facilitators[member.userId])) {
-          this.deleteTranscript(member.userId, member.roomId);
+              facilitatorInRoom = true
-          this.localStorage.removeItem(`${member.roomId}-facilitator`)
+            }
-          this.localStorage.removeItem(`${member.roomId}-transcript`)
+          })
-          this.client.leave(member.roomId)
+
+          if (!facilitatorInRoom) {
+            this.sendBotSignal(member.roomId, BOT_SIGNAL_END_CHAT)
+          }
+
+        } catch(err) {
+          logger.log("error", `ERROR SENDING BOT SIGNAL ==> ${err}`);
         }
       }
     })
   }
 
+  setTimeoutforFacilitator(roomId) {
+    setTimeout(() => {
+      const stillWaiting = this.localStorage.getItem(`${roomId}-waiting`)
+      if (stillWaiting) {
+        this.sendBotSignal(roomId, BOT_SIGNAL_END_CHAT)
+      }
+    }, this.config.MAX_WAIT_TIME)
+  }
+
+  setInactivityTimeout(roomId) {
+    const oldTimeout = this.inactivityTimers[roomId];
+
+    if (oldTimeout) {
+      clearTimeout(oldTimeout);
+    }
+
+    const newTimeout = setTimeout(() => {
+      this.sendTextMessage(
+        roomId,
+        `This chat has been closed due to inactivity.`
+      );
+      this.sendBotSignal(roomId, BOT_SIGNAL_END_CHAT)
+    }, this.config.MAX_INACTIVE)
+
+    this.inactivityTimers[roomId] = newTimeout;
+  }
+
   async setMessageListeners() {
     // encrypted messages
     this.client.on("Event.decrypted", (event, err) => {
@@ -529,6 +643,18 @@ class OcrccBot {
     })
   }
 
+  async sendBotSignal (roomId, signal, args) {
+    let content = {
+      signal: signal,
+      args: args,
+    }
+    try {
+      await this.client.sendStateEvent(roomId, 'm.bot.signal', content)
+    } catch(err) {
+      logger.log('error', "ERROR SENDING BOT SIGNAL => " + err)
+    }
+  }
+
   async start() {
     const localStorage = this.createLocalStorage();
     this.localStorage = localStorage
@@ -551,12 +677,18 @@ class OcrccBot {
       };
 
       this.client = matrix.createClient(opts);
-      await this.deleteOldDevices()
-      await this.trackJoinedRooms()
       await this.client.initCrypto()
-      await this.setMembershipListeners();
-      await this.setMessageListeners();
       this.client.startClient({ initialSyncLimit: 0 })
+
+      this.client.once('sync', async (state, prevState, data) => {
+        logger.log("info", `SYNC STATUS: ${state}`)
+        if (state === 'PREPARED') {
+          await this.deleteOldDevices()
+          await this.trackJoinedRooms()
+          await this.setMembershipListeners();
+          await this.setMessageListeners();
+        }
+      });
     } catch(err) {
       this.handleBotCrash(undefined, err);
       logger.log("error", `ERROR INITIALIZING CLIENT: ${err}`);

src/bot.test.js

@@ -32,7 +32,8 @@ import {
   mockKick,
   mockGetJoinedRoomMembers,
   mockGetUser,
-  mockGetGroupUsers
+  mockGetGroupUsers,
+  mockSendStateEvent,
 } from "matrix-js-sdk";
 
 import OcrccBot from './bot'
@@ -100,6 +101,7 @@ describe('OcrccBot', () => {
     mockSendTextMessage.mockClear()
     mockAppendFileSync.mockClear()
     mockGetGroupUsers.mockClear()
+    mockSendStateEvent.mockClear()
   })
 
 
@@ -325,4 +327,17 @@ describe('OcrccBot', () => {
       expect(mockStartClient).toHaveBeenCalled()
     })
   })
+
+  test('#sendBotSignal should send custom state event', () => {
+    const bot = new OcrccBot(botConfig)
+    bot.start()
+    const test_room_id = 'test_room_id'
+    const signal = 'END_CHAT'
+
+    bot.sendBotSignal(test_room_id, signal)
+
+    waitForExpect(() => {
+      expect(mockSendStateEvent).toHaveBeenCalledWith(test_room_id, 'm.bot.signal', { signal })
+    })
+  })
 })

src/encrypt-attachment.js

@@ -0,0 +1,156 @@
+// this is from https://github.com/matrix-org/browser-encrypt-attachment
+// which is the library used by matrix-reack-sdk to encrypt and decrypt attachments
+// just dropped in node-webcrypto-ossl to replace window.crypto
+// and Buffer for base64 encoding/decoding instead of window.btoa/window.atob
+
+
+/**
+ * Encrypt an attachment.
+ * @param {ArrayBuffer} plaintextBuffer The attachment data buffer.
+ * @return {Promise} A promise that resolves with an object when the attachment is encrypted.
+ *      The object has a "data" key with an ArrayBuffer of encrypted data and an "info" key
+ *      with an object containing the info needed to decrypt the data.
+ */
+
+const { Crypto } = require("node-webcrypto-ossl");
+const crypto = new Crypto();
+
+function encryptAttachment(plaintextBuffer) {
+    var cryptoKey; // The AES key object.
+    var exportedKey; // The AES key exported as JWK.
+    var ciphertextBuffer; // ArrayBuffer of encrypted data.
+    var sha256Buffer; // ArrayBuffer of digest.
+    var ivArray; // Uint8Array of AES IV
+    // Generate an IV where the first 8 bytes are random and the high 8 bytes
+    // are zero. We set the counter low bits to 0 since it makes it unlikely
+    // that the 64 bit counter will overflow.
+    ivArray = new Uint8Array(16);
+    crypto.getRandomValues(ivArray.subarray(0,8));
+    // Load the encryption key.
+    return crypto.subtle.generateKey(
+        {"name": "AES-CTR", length: 256}, true, ["encrypt", "decrypt"]
+    ).then(function(generateKeyResult) {
+        cryptoKey = generateKeyResult;
+        // Export the Key as JWK.
+        return crypto.subtle.exportKey("jwk", cryptoKey);
+    }).then(function(exportKeyResult) {
+        exportedKey = exportKeyResult;
+        // Encrypt the input ArrayBuffer.
+        // Use half of the iv as the counter by setting the "length" to 64.
+        return crypto.subtle.encrypt(
+            {name: "AES-CTR", counter: ivArray, length: 64}, cryptoKey, plaintextBuffer
+        );
+    }).then(function(encryptResult) {
+        ciphertextBuffer = encryptResult;
+        // SHA-256 the encrypted data.
+        return crypto.subtle.digest("SHA-256", ciphertextBuffer);
+    }).then(function (digestResult) {
+        sha256Buffer = digestResult;
+
+        return {
+            data: ciphertextBuffer,
+            info: {
+                v: "v2",
+                key: exportedKey,
+                iv: encodeBase64(ivArray),
+                hashes: {
+                    sha256: encodeBase64(new Uint8Array(sha256Buffer)),
+                },
+            },
+        };
+    });
+}
+
+/**
+ * Decrypt an attachment.
+ * @param {ArrayBuffer} ciphertextBuffer The encrypted attachment data buffer.
+ * @param {Object} info The information needed to decrypt the attachment.
+ * @param {Object} info.key AES-CTR JWK key object.
+ * @param {string} info.iv Base64 encoded 16 byte AES-CTR IV.
+ * @param {string} info.hashes.sha256 Base64 encoded SHA-256 hash of the ciphertext.
+ * @return {Promise} A promise that resolves with an ArrayBuffer when the attachment is decrypted.
+ */
+function decryptAttachment(ciphertextBuffer, info) {
+
+    if (info === undefined || info.key === undefined || info.iv === undefined
+        || info.hashes === undefined || info.hashes.sha256 === undefined) {
+       throw new Error("Invalid info. Missing info.key, info.iv or info.hashes.sha256 key");
+    }
+
+    var cryptoKey; // The AES key object.
+    var ivArray = decodeBase64(info.iv);
+    var expectedSha256base64 = info.hashes.sha256;
+    // Load the AES from the "key" key of the info object.
+    return crypto.subtle.importKey(
+        "jwk", info.key, {"name": "AES-CTR"}, false, ["encrypt", "decrypt"]
+    ).then(function (importKeyResult) {
+        cryptoKey = importKeyResult;
+        // Check the sha256 hash
+        return crypto.subtle.digest("SHA-256", ciphertextBuffer);
+    }).then(function (digestResult) {
+        if (encodeBase64(new Uint8Array(digestResult)) != expectedSha256base64) {
+            throw new Error("Mismatched SHA-256 digest");
+        }
+        var counterLength;
+        if (info.v == "v1" || info.v == "v2") {
+            // Version 1 and 2 use a 64 bit counter.
+            counterLength = 64;
+        } else {
+            // Version 0 uses a 128 bit counter.
+            counterLength = 128;
+        }
+        return crypto.subtle.decrypt(
+            {name: "AES-CTR", counter: ivArray, length: counterLength}, cryptoKey, ciphertextBuffer
+        );
+    });
+}
+
+/**
+ * Encode a typed array of uint8 as base64.
+ * @param {Uint8Array} uint8Array The data to encode.
+ * @return {string} The base64 without padding.
+ */
+function encodeBase64(uint8Array) {
+    // Misinterpt the Uint8Array as Latin-1.
+    // window.btoa expects a unicode string with codepoints in the range 0-255.
+    var latin1String = String.fromCharCode.apply(null, uint8Array);
+    // Use the builtin base64 encoder.
+    // var paddedBase64 = window.btoa(latin1String);
+    var paddedBase64 = Buffer.from(latin1String, 'binary').toString('base64')
+    // Calculate the unpadded length.
+    var inputLength = uint8Array.length;
+    var outputLength = 4 * Math.floor((inputLength + 2) / 3) + (inputLength + 2) % 3 - 2;
+    // Return the unpadded base64.
+    return paddedBase64.slice(0, outputLength);
+}
+
+/**
+ * Decode a base64 string to a typed array of uint8.
+ * This will decode unpadded base64, but will also accept base64 with padding.
+ * @param {string} base64 The unpadded base64 to decode.
+ * @return {Uint8Array} The decoded data.
+ */
+function decodeBase64(base64) {
+    // Pad the base64 up to the next multiple of 4.
+    var paddedBase64 = base64 + "===".slice(0, (4 - base64.length % 4) % 4);
+    // Decode the base64 as a misinterpreted Latin-1 string.
+    // window.atob returns a unicode string with codepoints in the range 0-255.
+    // var latin1String = window.atob(paddedBase64);
+    var latin1String = Buffer.from(paddedBase64, 'base64').toString('binary')
+    // Encode the string as a Uint8Array as Latin-1.
+    var uint8Array = new Uint8Array(latin1String.length);
+    for (var i = 0; i < latin1String.length; i++) {
+        uint8Array[i] = latin1String.charCodeAt(i);
+    }
+    return uint8Array;
+}
+
+try {
+    exports.encryptAttachment = encryptAttachment;
+    exports.decryptAttachment = decryptAttachment;
+}
+catch (e) {
+    // Ignore unknown variable "exports" errors when this is loaded directly into a browser
+    // This means that we can test it without having to use browserify.
+    // The intention is that the library is used using browserify.
+}

src/index.js

@@ -5,6 +5,7 @@ const KICK_REASON = "A facilitator has already joined this chat.";
 const BOT_ERROR_MESSAGE =
   "Something went wrong on our end, please restart the chat and try again.";
 const MAX_RETRIES = 3;
+
 const {
   MATRIX_SERVER_URL,
   BOT_USERNAME,
@@ -13,6 +14,9 @@ const {
   BOT_DISPLAY_NAME,
   FACILITATOR_ROOM_ID,
   CAPTURE_TRANSCRIPTS,
+  CHAT_NOT_AVAILABLE_MESSAGE,
+  MAX_WAIT_TIME,
+  MAX_INACTIVE,
 } = process.env;
 
 const botConfig = {
@@ -27,6 +31,9 @@ const botConfig = {
   BOT_DISPLAY_NAME,
   FACILITATOR_ROOM_ID,
   CAPTURE_TRANSCRIPTS,
+  CHAT_NOT_AVAILABLE_MESSAGE,
+  MAX_WAIT_TIME,
+  MAX_INACTIVE,
 }
 
 import OcrccBot from './bot'

yarn.lock

@@ -1257,6 +1257,23 @@
     "@types/yargs" "^15.0.0"
     chalk "^3.0.0"
 
+"@peculiar/asn1-schema@^2.0.1":
+  version "2.0.8"
+  resolved "https://registry.yarnpkg.com/@peculiar/asn1-schema/-/asn1-schema-2.0.8.tgz#bafb74388590f6ec3d53d1b2a4fdbe66d44224a4"
+  integrity sha512-D8ZqT61DdzuXfrILNvtdf7MUcTY2o9WHwmF0WgTKPEGNY5SDxNAjBY3enuwV9SXcSuCAwWac9c9v0vsswB1NIw==
+  dependencies:
+    "@types/asn1js" "^0.0.1"
+    asn1js "^2.0.26"
+    pvtsutils "^1.0.10"
+    tslib "^1.11.1"
+
+"@peculiar/json-schema@^1.1.10":
+  version "1.1.12"
+  resolved "https://registry.yarnpkg.com/@peculiar/json-schema/-/json-schema-1.1.12.tgz#fe61e85259e3b5ba5ad566cb62ca75b3d3cd5339"
+  integrity sha512-coUfuoMeIB7B8/NMekxaDzLhaYmp0HZNPEjYRm9goRou8UZIC3z21s0sL9AWoCw4EG876QyO3kYrc61WNF9B/w==
+  dependencies:
+    tslib "^2.0.0"
+
 "@sinonjs/commons@^1.7.0":
   version "1.7.1"
   resolved "https://registry.yarnpkg.com/@sinonjs/commons/-/commons-1.7.1.tgz#da5fd19a5f71177a53778073978873964f49acf1"
@@ -1264,6 +1281,13 @@
   dependencies:
     type-detect "4.0.8"
 
+"@types/asn1js@^0.0.1":
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/@types/asn1js/-/asn1js-0.0.1.tgz#ef8b9f9708cb1632a1c3a9cd27717caabe793bc2"
+  integrity sha1-74uflwjLFjKhw6nNJ3F8qr55O8I=
+  dependencies:
+    "@types/pvutils" "*"
+
 "@types/babel__core@^7.1.0":
   version "7.1.6"
   resolved "https://registry.yarnpkg.com/@types/babel__core/-/babel__core-7.1.6.tgz#16ff42a5ae203c9af1c6e190ed1f30f83207b610"
@@ -1322,6 +1346,11 @@
     "@types/istanbul-lib-coverage" "*"
     "@types/istanbul-lib-report" "*"
 
+"@types/pvutils@*":
+  version "0.0.2"
+  resolved "https://registry.yarnpkg.com/@types/pvutils/-/pvutils-0.0.2.tgz#e21684962cfa58ac920fd576d90556032dc86009"
+  integrity sha512-CgQAm7pjyeF3Gnv78ty4RBVIfluB+Td+2DR8iPaU0prF18pkzptHHP+DoKPfpsJYknKsVZyVsJEu5AuGgAqQ5w==
+
 "@types/stack-utils@^1.0.1":
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/@types/stack-utils/-/stack-utils-1.0.1.tgz#0a851d3bd96498fa25c33ab7278ed3bd65f06c3e"
@@ -1486,6 +1515,13 @@ asn1@~0.2.3:
   dependencies:
     safer-buffer "~2.1.0"
 
+asn1js@^2.0.26:
+  version "2.0.26"
+  resolved "https://registry.yarnpkg.com/asn1js/-/asn1js-2.0.26.tgz#0a6d435000f556a96c6012969d9704d981b71251"
+  integrity sha512-yG89F0j9B4B0MKIcFyWWxnpZPLaNTjCj4tkE3fjbAoo0qmpGw0PYYqSbX/4ebnd9Icn8ZgK4K1fvDyEtW1JYtQ==
+  dependencies:
+    pvutils latest
+
 assert-plus@1.0.0, assert-plus@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/assert-plus/-/assert-plus-1.0.0.tgz#f12e0f3c5d77b0b1cdd9146942e4e96c1e4dd525"
@@ -3863,6 +3899,11 @@ mkdirp@^0.5.1:
   dependencies:
     minimist "0.0.8"
 
+mkdirp@^1.0.4:
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/mkdirp/-/mkdirp-1.0.4.tgz#3eb5ed62622756d79a5f0e2a221dfebad75c2f7e"
+  integrity sha512-vVqVZQyf3WLx2Shd0qJ9xuvqgAyKPLAiqITEtqW0oIUjzo3PePDd6fW9iFz30ef7Ysp/oiWqbhszeGWW2T6Gzw==
+
 ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
@@ -3873,7 +3914,7 @@ ms@^2.1.1:
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
   integrity sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==
 
-nan@^2.12.1:
+nan@^2.12.1, nan@^2.14.1:
   version "2.14.1"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.14.1.tgz#d7be34dfa3105b91494c3147089315eff8874b01"
   integrity sha512-isWHgVjnFjh2x2yuJ/tj3JbwoHu3UC2dX5G/88Cm24yB6YopVgxvBObDY7n5xW6ExmFhJpSEQqFPvq9zaXc8Jw==
@@ -3953,6 +3994,17 @@ node-releases@^1.1.53:
   resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.53.tgz#2d821bfa499ed7c5dffc5e2f28c88e78a08ee3f4"
   integrity sha512-wp8zyQVwef2hpZ/dJH7SfSrIPD6YoJz6BDQDpGEkcA0s3LpAQoxBIYmfIq6QAhC1DhwsyCgTaTTcONwX8qzCuQ==
 
+node-webcrypto-ossl@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/node-webcrypto-ossl/-/node-webcrypto-ossl-2.1.0.tgz#cee0e22fa9d9325a19f260539d0854ba143595db"
+  integrity sha512-diC2LLQKKo41XxrgdT2MmH4mxWNoeCwjS0+uSLfui3rCtxai8cdLLs0TKT0z9Mq8LZ4eMAkuU4FFmEOHk6CbsQ==
+  dependencies:
+    mkdirp "^1.0.4"
+    nan "^2.14.1"
+    pvtsutils "^1.0.10"
+    tslib "^1.11.2"
+    webcrypto-core "^1.1.0"
+
 nodemon@^2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/nodemon/-/nodemon-2.0.2.tgz#9c7efeaaf9b8259295a97e5d4585ba8f0cbe50b0"
@@ -4354,6 +4406,18 @@ punycode@^2.1.0, punycode@^2.1.1:
   resolved "https://registry.yarnpkg.com/punycode/-/punycode-2.1.1.tgz#b58b010ac40c22c5657616c8d2c2c02c7bf479ec"
   integrity sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==
 
+pvtsutils@^1.0.10:
+  version "1.0.10"
+  resolved "https://registry.yarnpkg.com/pvtsutils/-/pvtsutils-1.0.10.tgz#157d0fcb853f570d32e0f8788179f3057eacdf38"
+  integrity sha512-8ZKQcxnZKTn+fpDh7wL4yKax5fdl3UJzT8Jv49djZpB/dzPxacyN1Sez90b6YLdOmvIr9vaySJ5gw4aUA1EdSw==
+  dependencies:
+    tslib "^1.10.0"
+
+pvutils@latest:
+  version "1.0.17"
+  resolved "https://registry.yarnpkg.com/pvutils/-/pvutils-1.0.17.tgz#ade3c74dfe7178944fe44806626bd2e249d996bf"
+  integrity sha512-wLHYUQxWaXVQvKnwIDWFVKDJku9XDCvyhhxoq8dc5MFdIlRenyPI9eSfEtcvgHgD7FlvCyGAlWgOzRnZD99GZQ==
+
 qs@^6.5.2:
   version "6.9.1"
   resolved "https://registry.yarnpkg.com/qs/-/qs-6.9.1.tgz#20082c65cb78223635ab1a9eaca8875a29bf8ec9"
@@ -5161,6 +5225,16 @@ triple-beam@^1.2.0, triple-beam@^1.3.0:
   resolved "https://registry.yarnpkg.com/triple-beam/-/triple-beam-1.3.0.tgz#a595214c7298db8339eeeee083e4d10bd8cb8dd9"
   integrity sha512-XrHUvV5HpdLmIj4uVMxHggLbFSZYIn7HEWsqePZcI50pco+MPqJ50wMGY794X7AOOhxOBAjbkqfAbEe/QMp2Lw==
 
+tslib@^1.10.0, tslib@^1.11.1, tslib@^1.11.2:
+  version "1.13.0"
+  resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.13.0.tgz#c881e13cc7015894ed914862d276436fa9a47043"
+  integrity sha512-i/6DQjL8Xf3be4K/E6Wgpekn5Qasl1usyw++dAA35Ue5orEn65VIxOA+YvNNl9HV3qv70T7CNwjODHZrLwvd1Q==
+
+tslib@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/tslib/-/tslib-2.0.0.tgz#18d13fc2dce04051e20f074cc8387fd8089ce4f3"
+  integrity sha512-lTqkx847PI7xEDYJntxZH89L2/aXInsyF2luSafe/+0fHOMjlBNXdH6th7f70qxLDhul7KZK0zC8V5ZIyHl0/g==
+
 tunnel-agent@^0.6.0:
   version "0.6.0"
   resolved "https://registry.yarnpkg.com/tunnel-agent/-/tunnel-agent-0.6.0.tgz#27a5dea06b36b04a0a9966774b290868f0fc40fd"
@@ -5392,6 +5466,17 @@ walker@^1.0.7, walker@~1.0.5:
   dependencies:
     makeerror "1.0.x"
 
+webcrypto-core@^1.1.0:
+  version "1.1.2"
+  resolved "https://registry.yarnpkg.com/webcrypto-core/-/webcrypto-core-1.1.2.tgz#c522a9e5596688f2b6bb19e2d336f68efa8bdd57"
+  integrity sha512-LxM/dTcXr/ZnwwKLox0tGEOIqvP7KIJ4Hk/fFPX20tr1EgqTmpEFZinmu4FzoGVbs6e4jI1priQKCDrOBD3L6w==
+  dependencies:
+    "@peculiar/asn1-schema" "^2.0.1"
+    "@peculiar/json-schema" "^1.1.10"
+    asn1js "^2.0.26"
+    pvtsutils "^1.0.10"
+    tslib "^1.11.2"
+
 webidl-conversions@^4.0.2:
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/webidl-conversions/-/webidl-conversions-4.0.2.tgz#a855980b1f0b6b359ba1d5d9fb39ae941faa63ad"