Prompting the user to reset session on invalid ciphertext

_locales/en/messages.json

@@ -2241,5 +2241,18 @@
   },
   "noFriendsToAdd": {
     "message": "no friends to add"
+  },
+  "couldNotDecryptMessage": {
+    "message": "Couldn't decrypt a message"
+  },
+  "confirmSessionRestore": {
+    "message":
+      "Would you like to start a new session with $pubkey$? Only do so if you know this pubkey.",
+    "placeholders": {
+      "pubkey": {
+        "content": "$1",
+        "example": ""
+      }
+    }
   }
 }

background.html

@@ -819,6 +819,7 @@ <h4 class='section-toggle'>Link device to an existing account</h4>
   <script type='text/javascript' src='js/views/device_pairing_dialog_view.js'></script>
   <script type='text/javascript' src='js/views/device_pairing_words_dialog_view.js'></script>
   <script type='text/javascript' src='js/views/create_group_dialog_view.js'></script>
+  <script type='text/javascript' src='js/views/confirm_session_reset_view.js'></script>
   <script type='text/javascript' src='js/views/edit_profile_dialog_view.js'></script>
   <script type='text/javascript' src='js/views/invite_friends_dialog_view.js'></script>
 

js/background.js

@@ -998,6 +998,12 @@
       }
     });
 
+    Whisper.events.on('showSessionRestoreConfirmation', options => {
+      if (appView) {
+        appView.showSessionRestoreConfirmation(options);
+      }
+    });
+
     Whisper.events.on('showNicknameDialog', options => {
       if (appView) {
         appView.showNicknameDialog(options);
@@ -1889,6 +1895,48 @@
   }
 
   async function onError(ev) {
+    const noSession =
+      ev.error &&
+      ev.error.message &&
+      ev.error.message.indexOf('No record for device') === 0;
+    const pubkey = ev.proto.source;
+
+    if (noSession) {
+      const convo = await ConversationController.getOrCreateAndWait(
+        pubkey,
+        'private'
+      );
+
+      if (!convo.get('sessionRestoreSeen')) {
+        convo.set({ sessionRestoreSeen: true });
+
+        await window.Signal.Data.updateConversation(
+          convo.id,
+          convo.attributes,
+          { Conversation: Whisper.Conversation }
+        );
+
+        window.Whisper.events.trigger('showSessionRestoreConfirmation', {
+          pubkey,
+          onOk: () => {
+            convo.sendMessage('', null, null, null, null, {
+              sessionRestoration: true,
+            });
+          },
+        });
+      } else {
+        window.log.verbose(
+          `Already seen session restore for pubkey: ${pubkey}`
+        );
+        if (ev.confirm) {
+          ev.confirm();
+        }
+      }
+
+      // We don't want to display any failed messages in the conversation:
+      return;
+    }
+
     const { error } = ev;
     window.log.error('background onError:', Errors.toLogFormat(error));
 

js/models/conversations.js

@@ -1423,7 +1423,8 @@
       attachments,
       quote,
       preview,
-      groupInvitation = null
+      groupInvitation = null,
+      otherOptions = {}
     ) {
       this.clearTypingTimers();
 
@@ -1514,9 +1515,13 @@
           messageWithSchema.source = textsecure.storage.user.getNumber();
           messageWithSchema.sourceDevice = 1;
         }
+
+        const { sessionRestoration = false } = otherOptions;
+
         const attributes = {
           ...messageWithSchema,
           groupInvitation,
+          sessionRestoration,
           id: window.getGuid(),
         };
 
@@ -1597,6 +1602,7 @@
         }
 
         options.groupInvitation = groupInvitation;
+        options.sessionRestoration = sessionRestoration;
 
         const groupNumbers = this.getRecipients();
 

js/models/messages.js

@@ -102,6 +102,8 @@
           this.propsForResetSessionNotification = this.getPropsForResetSessionNotification();
         } else if (this.isGroupUpdate()) {
           this.propsForGroupNotification = this.getPropsForGroupNotification();
+        } else if (this.isSessionRestoration()) {
+          // do nothing
         } else if (this.isFriendRequest()) {
           this.propsForFriendRequest = this.getPropsForFriendRequest();
         } else if (this.isGroupInvitation()) {
@@ -270,6 +272,13 @@
     isGroupInvitation() {
       return !!this.get('groupInvitation');
     },
+    isSessionRestoration() {
+      const flag = textsecure.protobuf.DataMessage.Flags.SESSION_RESTORE;
+      // eslint-disable-next-line no-bitwise
+      const sessionRestoreFlag = !!(this.get('flags') & flag);
+
+      return !!this.get('sessionRestoration') || sessionRestoreFlag;
+    },
     getNotificationText() {
       const description = this.getDescription();
       if (description) {
@@ -390,6 +399,16 @@
       }
       const conversation = await this.getSourceDeviceConversation();
 
+      // If we somehow received an old friend request (e.g. after having restored
+      // from seed, we won't be able to accept it, we should initiate our own
+      // friend request to reset the session:
+      if (conversation.get('sessionRestoreSeen')) {
+        conversation.sendMessage('', null, null, null, null, {
+          sessionRestoration: true,
+        });
+        return;
+      }
+
       this.set({ friendStatus: 'accepted' });
       await window.Signal.Data.saveMessage(this.attributes, {
         Message: Whisper.Message,
@@ -1922,6 +1941,15 @@
         initialMessage.flags ===
         textsecure.protobuf.DataMessage.Flags.BACKGROUND_FRIEND_REQUEST;
 
+      if (
+        // eslint-disable-next-line no-bitwise
+        initialMessage.flags &
+        textsecure.protobuf.DataMessage.Flags.SESSION_RESTORE
+      ) {
+        // Show that the session reset is "in progress" even though we had a valid session
+        this.set({ endSessionType: 'ongoing' });
+      }
+
       if (message.isFriendRequest() && backgroundFrReq) {
         // Check if the contact is a member in one of our private groups:
         const groupMember = window

js/views/app_view.js

@@ -250,6 +250,10 @@
       const dialog = new Whisper.UpdateGroupDialogView(groupConvo);
       this.el.append(dialog.el);
     },
+    showSessionRestoreConfirmation(options) {
+      const dialog = new Whisper.ConfirmSessionResetView(options);
+      this.el.append(dialog.el);
+    },
     showLeaveGroupDialog(groupConvo) {
       const dialog = new Whisper.LeaveGroupDialogView(groupConvo);
       this.el.append(dialog.el);

js/views/confirm_session_reset_view.js

@@ -0,0 +1,50 @@
+/* global Whisper, i18n */
+
+// eslint-disable-next-line func-names
+(function() {
+  'use strict';
+
+  window.Whisper = window.Whisper || {};
+
+  Whisper.ConfirmSessionResetView = Whisper.View.extend({
+    className: 'loki-dialog modal',
+    initialize({ pubkey, onOk }) {
+      this.title = i18n('couldNotDecryptMessage');
+
+      this.onOk = onOk;
+      this.messageText = i18n('confirmSessionRestore', pubkey);
+      this.okText = i18n('yes');
+      this.cancelText = i18n('cancel');
+
+      this.close = this.close.bind(this);
+      this.confirm = this.confirm.bind(this);
+
+      this.$el.focus();
+      this.render();
+    },
+    render() {
+      this.dialogView = new Whisper.ReactWrapperView({
+        className: 'leave-group-dialog',
+        Component: window.Signal.Components.ConfirmDialog,
+        props: {
+          titleText: this.title,
+          messageText: this.messageText,
+          okText: this.okText,
+          cancelText: this.cancelText,
+          onConfirm: this.confirm,
+          onClose: this.close,
+        },
+      });
+
+      this.$el.append(this.dialogView.el);
+      return this;
+    },
+    async confirm() {
+      this.onOk();
+      this.close();
+    },
+    close() {
+      this.remove();
+    },
+  });
+})();

js/views/message_view.js

@@ -69,6 +69,11 @@
           Component: Components.GroupNotification,
           props: this.model.propsForGroupNotification,
         };
+      } else if (this.model.isSessionRestoration()) {
+        return {
+          Component: Components.ResetSessionNotification,
+          props: this.model.getPropsForResetSessionNotification(),
+        };
       } else if (this.model.propsForFriendRequest) {
         return {
           Component: Components.FriendRequest,

libtextsecure/message_receiver.js

@@ -821,7 +821,6 @@ MessageReceiver.prototype.extend({
     } else {
       handleSessionReset = async result => result;
     }
-
     switch (envelope.type) {
       case textsecure.protobuf.Envelope.Type.CIPHERTEXT:
         window.log.info('message from', this.getEnvelopeId(envelope));
@@ -971,6 +970,9 @@ MessageReceiver.prototype.extend({
       .catch(error => {
         let errorToThrow = error;
 
+        const noSession =
+          error && error.message.indexOf('No record for device') === 0;
+
         if (error && error.message === 'Unknown identity key') {
           // create an error that the UI will pick up and ask the
           // user if they want to re-negotiate
@@ -980,8 +982,8 @@ MessageReceiver.prototype.extend({
             buffer.toArrayBuffer(),
             error.identityKey
           );
-        } else {
-          // re-throw
+        } else if (!noSession) {
+          // We want to handle "no-session" error, not re-throw it
           throw error;
         }
         const ev = new Event('error');
@@ -1850,6 +1852,8 @@ MessageReceiver.prototype.extend({
       decrypted.attachments = [];
     } else if (decrypted.flags & FLAGS.BACKGROUND_FRIEND_REQUEST) {
       // do nothing
+    } else if (decrypted.flags & FLAGS.SESSION_RESTORE) {
+      // do nothing
     } else if (decrypted.flags & FLAGS.UNPAIRING_REQUEST) {
       // do nothing
     } else if (decrypted.flags !== 0) {

libtextsecure/sendmessage.js

@@ -28,6 +28,7 @@ function Message(options) {
   this.profileKey = options.profileKey;
   this.profile = options.profile;
   this.groupInvitation = options.groupInvitation;
+  this.sessionRestoration = options.sessionRestoration || false;
 
   if (!(this.recipients instanceof Array)) {
     throw new Error('Invalid recipient list');
@@ -171,6 +172,10 @@ Message.prototype = {
       );
     }
 
+    if (this.sessionRestoration) {
+      proto.flags = textsecure.protobuf.DataMessage.Flags.SESSION_RESTORE;
+    }
+
     this.dataMessage = proto;
     return proto;
   },
@@ -952,7 +957,7 @@ MessageSender.prototype = {
       ? textsecure.protobuf.DataMessage.Flags.BACKGROUND_FRIEND_REQUEST
       : undefined;
 
-    const { groupInvitation } = options;
+    const { groupInvitation, sessionRestoration } = options;
 
     return this.sendMessage(
       {
@@ -968,6 +973,7 @@ MessageSender.prototype = {
         profile,
         flags,
         groupInvitation,
+        sessionRestoration,
       },
       options
     );

protos/SignalService.proto

@@ -105,6 +105,7 @@ message DataMessage {
     END_SESSION               = 1;
     EXPIRATION_TIMER_UPDATE   = 2;
     PROFILE_KEY_UPDATE        = 4;
+    SESSION_RESTORE           = 64;
     UNPAIRING_REQUEST         = 128;
     BACKGROUND_FRIEND_REQUEST = 256;
   }

test/index.html

@@ -576,6 +576,7 @@ <h3>{{ message }}</h3>
   <script type='text/javascript' src='../js/views/banner_view.js' data-cover></script>
   <script type='text/javascript' src='../js/views/clear_data_view.js'></script>
   <script type='text/javascript' src='../js/views/create_group_dialog_view.js'></script>
+  <script type='text/javascript' src='../js/views/confirm_session_reset_view.js'></script>
   <script type='text/javascript' src='../js/views/invite_friends_dialog_view.js'></script>
   <script type='text/javascript' src='../js/views/beta_release_disclaimer_view.js'></script>