drop groupUpdates which happened before we joined the group

js/models/conversations.d.ts

@@ -14,6 +14,7 @@ interface ConversationAttributes {
   isArchived: boolean;
   active_at: number;
   timestamp: number; // timestamp of what?
+  lastJoinedTimestamp: number; // ClosedGroupV2: last time we were added to this group
   groupAdmins?: Array<string>;
   isKickedFromGroup?: boolean;
   avatarPath?: string;

js/models/conversations.js

@@ -58,6 +58,7 @@
         isKickedFromGroup: false,
         profileSharing: false,
         left: false,
+        lastJoinedTimestamp: new Date('1970-01-01Z00:00:00:000').getTime(),
       };
     },
 

js/views/create_group_dialog_view.js

@@ -189,7 +189,7 @@
 
       const xor = _.xor(notPresentInNew, notPresentInOld);
       if (xor.length === 0) {
-        window.log.log(
+        window.log.info(
           'skipping group update: no detected changes in group member list'
         );
 

ts/components/session/RegistrationTabs.tsx

@@ -961,7 +961,7 @@ export class RegistrationTabs extends React.Component<any, State> {
       const secretWords = window.mnemonic.pubkey_to_secret_words(pubkey);
       this.setState({ secretWords });
     } catch (e) {
-      window.log.log(e);
+      window.log.info(e);
       await this.resetRegistration();
 
       this.setState({

ts/receiver/closedGroupsV2.ts

@@ -181,6 +181,15 @@ async function handleNewClosedGroupV2(
   const groupId = toHex(publicKey);
   const members = membersAsData.map(toHex);
   const admins = adminsAsData.map(toHex);
+
+  const ourPrimary = await UserUtil.getPrimary();
+  if (!members.includes(ourPrimary.key)) {
+    log.info(
+      'Got a new group message but apparently we are not a member of it. Dropping it.'
+    );
+    await removeFromCache(envelope);
+    return;
+  }
   // FIXME maybe we should handle an expiretimer here too? And on ClosedGroupV2 updates?
 
   const maybeConvo = ConversationController.getInstance().get(groupId);
@@ -198,6 +207,7 @@ async function handleNewClosedGroupV2(
       // Enable typing:
       maybeConvo.set('isKickedFromGroup', false);
       maybeConvo.set('left', false);
+      maybeConvo.set('lastJoinedTimestamp', Date.now());
     } else {
       log.warn(
         'Ignoring a closed group v2 message of type NEW: the conversation already exists'
@@ -222,14 +232,13 @@ async function handleNewClosedGroupV2(
     'incoming'
   );
 
-  // TODO: Check that we are even a part of this group
-
   convo.set('name', name);
   convo.set('members', members);
   // mark a closed group v2 as a medium group.
   // this field is used to poll for this groupPubKey on the swarm nodes, among other things
   convo.set('is_medium_group', true);
   convo.set('active_at', Date.now());
+  convo.set('lastJoinedTimestamp', Date.now());
 
   // We only set group admins on group creation
   convo.set('groupAdmins', admins);
@@ -272,6 +281,25 @@ async function handleUpdateClosedGroupV2(
     await removeFromCache(envelope);
     return;
   }
+
+  // Check that the message isn't from before the group was created
+  let lastJoinedTimestamp = convo.get('lastJoinedTimestamp');
+  // might happen for existing groups
+  if (!lastJoinedTimestamp) {
+    const aYearAgo = Date.now() - 1000 * 60 * 24 * 365;
+    convo.set({
+      lastJoinedTimestamp: aYearAgo,
+    });
+    lastJoinedTimestamp = aYearAgo;
+  }
+
+  if (envelope.timestamp <= lastJoinedTimestamp) {
+    window.log.warn(
+      'Got a group update with an older timestamp than when we joined this group last time. Dropping it'
+    );
+    await removeFromCache(envelope);
+    return;
+  }
   const curAdmins = convo.get('groupAdmins');
 
   // Check that the sender is a member of the group (before the update)
@@ -520,6 +548,8 @@ export async function createClosedGroupV2(
   // be sure to call this before sending the message.
   // the sending pipeline needs to know from GroupUtils when a message is for a medium group
   await ClosedGroupV2.updateOrCreateClosedGroupV2(groupDetails);
+  convo.set('lastJoinedTimestamp', Date.now());
+
   // Send a closed group update message to all members individually
   const promises = listOfMembers.map(async m => {
     const messageParams: ClosedGroupV2NewMessageParams = {

ts/receiver/contentMessage.ts

@@ -27,7 +27,7 @@ export async function handleContentMessage(envelope: EnvelopePlus) {
     const plaintext = await decrypt(envelope, envelope.content);
 
     if (!plaintext) {
-      window.log.warn('handleContentMessage: plaintext was falsey');
+      // window.log.warn('handleContentMessage: plaintext was falsey');
       return;
     } else if (plaintext instanceof ArrayBuffer && plaintext.byteLength === 0) {
       return;

ts/test/test-utils/utils/message.ts

@@ -91,6 +91,7 @@ export class MockConversation {
       isArchived: false,
       active_at: Date.now(),
       timestamp: Date.now(),
+      lastJoinedTimestamp: Date.now(),
       secondaryStatus: !this.isPrimary,
     };
   }