Token caching breaks deleted token refresh

[bars0um]

Environment

• Xcode version: 12.4 12D4E
• Firebase SDK version: 7.9.0
• Installation method: CocoaPods (select one)
• Firebase Component: Messaging

Steps to reproduce:

Delete your token and try to fetch a new one:

messaging().deleteToken();

messaging().getToken();

The returned token is not a fresh one and checking the firebase api shows that the relating instance id is no longer there.

curl https://iid.googleapis.com/iid/info/fEVWIR1VoErnl-..ASm? -H "Authorization:key=YTsagf32...-c_azdc4"

{"error":"No information found about this instance id."}

The only way to fix this is to remove the caching logic from the Firebase/InstanceID pod.

To prove that there is something wrong here, I've commented the cached token logic in Firebase/InstanceID/FIRInstanceID.m and this seems to resolve the issue.

#Firebase/InstanceID/FIRInstanceID.m
....

//    NSString *cachedToken = [self cachedTokenIfAvailable];
//    if (cachedToken) {
//      if (handler) {
//        result.token = cachedToken;
//        handler(result, nil);
//      }
//      // If no handler, simply return since client has generated iid and token.
//      return;
//    }
..
//        FIRInstanceIDTokenInfo *cachedTokenInfo =
//            [self.tokenManager cachedTokenInfoWithAuthorizedEntity:authorizedEntity scope:scope];
//        if (cachedTokenInfo) {
//          FIRInstanceIDAPNSInfo *optionsAPNSInfo =
//              [[FIRInstanceIDAPNSInfo alloc] initWithTokenOptionsDictionary:tokenOptions];
//          // Check if APNS Info is changed
//          if ((!cachedTokenInfo.APNSInfo && !optionsAPNSInfo) ||
//              [cachedTokenInfo.APNSInfo isEqualToAPNSInfo:optionsAPNSInfo]) {
//            // check if token is fresh
//            if ([cachedTokenInfo isFreshWithIID:identifier]) {
//              newHandler(cachedTokenInfo.token, nil);
//              return;
//            }
//          }
//        }
..

Relevant Code:

I've not had time to look at this closer, but something in the refresh token with iid logic is off. Appreciate if you could help shed light on this issue.

#Pods/FirebaseInstanceID/Firebase/InstanceID/FIRInstanceIDTokenInfo.m
...

- (BOOL)isFreshWithIID:(NSString *)IID {
  // Last fetch token cache time could be null if token is from legacy storage format. Then token is
  // considered not fresh and should be refreshed and overwrite with the latest storage format.
  if (!IID) {
    return NO;
  }
  if (!_cacheTime) {
    return NO;
  }

  // Check if it's consistent with IID
  if (![self.token hasPrefix:IID]) {
    return NO;
  }

  // Check if app has just been updated to a new version.
  NSString *currentAppVersion = FIRInstanceIDCurrentAppVersion();
  if (!_appVersion || ![_appVersion isEqualToString:currentAppVersion]) {
    FIRInstanceIDLoggerDebug(kFIRInstanceIDMessageCodeTokenManager004,
                             @"Invalidating cached token for %@ (%@) due to app version change.",
                             _authorizedEntity, _scope);
    return NO;
  }

  // Check if GMP App ID has changed
  NSString *currentFirebaseAppID = FIRInstanceIDFirebaseAppID();
  if (!_firebaseAppID || ![_firebaseAppID isEqualToString:currentFirebaseAppID]) {
    FIRInstanceIDLoggerDebug(
        kFIRInstanceIDMessageCodeTokenInfoFirebaseAppIDChanged,
        @"Invalidating cached token due to Firebase App IID change from %@ to %@", _firebaseAppID,
        currentFirebaseAppID);
    return NO;
  }

  // Check whether locale has changed, if yes, token needs to be updated with server for locale
  // information.
  if (FIRInstanceIDHasLocaleChanged()) {
    FIRInstanceIDLoggerDebug(kFIRInstanceIDMessageCodeTokenInfoLocaleChanged,
                             @"Invalidating cached token due to locale change");
    return NO;
  }

  // Locale is not changed, check whether token has been fetched within 7 days.
  NSTimeInterval lastFetchTokenTimestamp = [_cacheTime timeIntervalSince1970];
  NSTimeInterval currentTimestamp = FIRInstanceIDCurrentTimestampInSeconds();
  NSTimeInterval timeSinceLastFetchToken = currentTimestamp - lastFetchTokenTimestamp;
  return (timeSinceLastFetchToken < kDefaultFetchTokenInterval);
}

[charlotteliang]

@bars0um I'm not able to reproduce. Would you mind sharing debugLog with me?

To enable debug logging set the following application argument: -FIRDebugEnabled (see http://goo.gl/RfcP7r)

[bars0um]

@chliangGoogle thank you for your response and your help.

I've enabled the firebase debug log but the only message I get from the Messaging component is this:

7.9.0 - [Firebase/Messaging][I-FCM001000] FIRMessaging Remote Notifications proxy enabled, will swizzle remote notification receiver handlers. If you'd prefer to manually integrate Firebase Messaging, add "FirebaseAppDelegateProxyEnabled" to your Info.plist, and set it to NO. Follow the instructions at:
https://firebase.google.com/docs/cloud-messaging/ios/client#method_swizzling_in_firebase_messaging

However, if I step through with the debugger I can see that the call to getToken seems to end up with the cached value.

For better clarity the code to deleteToken and getToken (extracted from invertase's RNFBMessaging) is attached below.
I assume that the deleteTokenWithAuthorizedEntity is supposed to obliterate all reference to the current token, if not then perhaps this is the reason a cached value is returned when tokenWithAuthorizedEntity is called...

deleteToken:

RCT_EXPORT_METHOD(deleteToken:
  (NSString *) authorizedEntity
    :(NSString *) scope
    :(RCTPromiseResolveBlock) resolve
    :(RCTPromiseRejectBlock) reject
) {
  [[FIRInstanceID instanceID] deleteTokenWithAuthorizedEntity:authorizedEntity scope:scope handler:^(NSError *_Nullable error) {
    if (error) {
      [RNFBSharedUtils rejectPromiseWithNSError:reject error:error];
    } else {
      resolve([NSNull null]);
    }
  }];
}

getToken:

RCT_EXPORT_METHOD(getToken:
  (NSString *) authorizedEntity
    :(NSString *) scope
    :(RCTPromiseResolveBlock) resolve
    :(RCTPromiseRejectBlock) reject
) {
  #if !(TARGET_IPHONE_SIMULATOR)
  if ([UIApplication sharedApplication].isRegisteredForRemoteNotifications == NO) {
    [RNFBSharedUtils rejectPromiseWithUserInfo:reject userInfo:(NSMutableDictionary *) @{
        @"code": @"unregistered",
        @"message": @"You must be registered for remote messages before calling getToken, see messaging().registerDeviceForRemoteMessages().",
    }];
    return;
  }
  #endif

  if ([scope isEqualToString:@"FCM"] && [authorizedEntity isEqualToString:[FIRApp defaultApp].options.GCMSenderID]) {
    [[FIRInstanceID instanceID] instanceIDWithHandler:^(FIRInstanceIDResult *_Nullable result, NSError *_Nullable error) {
      if (error) {
        [RNFBSharedUtils rejectPromiseWithNSError:reject error:error];
      } else {
        resolve(result.token);
      }
    }];
  } else {
    NSDictionary *options = nil;
    if ([FIRMessaging messaging].APNSToken) {
      options = @{@"apns_token": [FIRMessaging messaging].APNSToken};
    }

    [[FIRInstanceID instanceID] tokenWithAuthorizedEntity:authorizedEntity scope:scope options:options handler:^(NSString *_Nullable identity, NSError *_Nullable error) {
      if (error) {
        [RNFBSharedUtils rejectPromiseWithNSError:reject error:error];
      } else {
        resolve(identity);
      }
    }];
  }
}

[charlotteliang]

I'm not able to reproduce with your code. Could you debug to figure out why debugLog is limited on your end? Without the debugLog it's hard for us to speculate.

Also InstanceID is deprecated along with non-default ("") scope. For the case that failed for you, are you using non-default scope ("")? such as "FCM" scope or some other custom scope?

Would it be possible to migrate to [FIRMessaging tokenWithCompletion:] and [FIRMessaging deleteTokenWithCompletion:] to see if that solves the issue?

[charlotteliang]

Another thing is if you delete a non-default token and call [FIRInstanceID instanceID] instanceIDWithHandler:, it will return the default token.

[bars0um]

Thanks chliangGoogle, I will try to find the time to sort out the debug log and let you know when I do.