New: Fitbit support added, app approved by Fitbit (see Fitbit Section and Fitbit App Store)
An idea was to have a Google Auth/2FA Client running on all Android-bound phones and watches. It includes:
- Contemporary high end Android phones running ver 6.0 or higher
- Contemporary Samsung Gear devices such as Gear S2, S3, Sport, Galaxy
- Android Wear watches
- Fitbit Versa and Ionic
The major benefit is that it integrates phone’s, Wear and Gear’s 2FA apps in a single solution and allows transferring accounts between peers in any direction: from phone to watch or vise versa. There is no need for Google’s stock app anymore, because the companion includes all GA functionality and adds features that stock GA app is currently missing.
The companion allows scanning Google’s QR bar code, which is a client/server shared secret used for generating one time passwords (OTP).
In addition, the Android’s companion can be also used to backup and restore all 2FA accounts. Backups could be encrypted using a password based encryption (PBE) with HMAC signature intended for verifying backup’s integrity (e.g. signature verification will fail if a password is not valid).
Plain backups are also supported, but not recommended, since they are stored in Android’s “Download” directory that can be accessed by other applications that are granted “read storage” permission.
Using Google Drive for backup/restore operations makes syncing accounts across all your Android, Gear and Wear devices simple.
Where and How to Start
To create a 2FA account on your phone using this app, you’ll need a shared secret, which is a Base32 code generated by your 2FA provider. How to get that code depends on a provider and the code is generated at the time when you enable 2FA in your web app. Instructions for getting the code for all Google accounts are provided here:
However, those instructions change often, so the best way is to read recent 2FA enabling instructions for each provider. The app was tested and actively used with the following 2FA providers:
The number of websites supporting 2FA grows fast and the list above will grow as well.
App Flavors and Their Usage
How to Choose Right App in Google Play Store
There are two apps in Google’s Play store and the simple guidance below will help you to make the right choice.
- “GAC – Google Auth Client” supports Samsung’s Gear and Android Phone. Choose this one if you want to have an authenticator that works as a standalone app on an Android phone, or if you want an Android phone and Gear app to work together. It’s free.
- “GACW – Google Auth Client for Wear” is very similar to the first one, except that in addition to Gear, it supports Android Wear and Fitbit devices as well. It also doesn’t have any ads. Choose this one if you need support for both Gear and Wear or Fitbit devices, don’t like ads, and don’t mind to spend $2.
How to Choose Right App in Samsung Store
There are three GAC apps in Samsung’s App store, and the guidance below will help you to to select the right one:
1. Client for Google Authenticator was created in 2015, supports many legacy devices such as Gear, Gear 2, Gear Neo, and Gear S, along with newer Gear S2, Gear S3, and Gear Sport. Buy this application only is you need support for legacy devices. If you have S2, S3 or Gear Sport, consider other two choices.
2. Client for Google Authenticator with Companion was created in 2017, supports Gear S2, S3 and Sport only, and requires Android’s companion to work. Use this app if you have S2, S3, Sport, and like additional Android’s companion features such as bar code scanning and backups, and don’t need support for Android’s Wear devices.
3. “GACW – Google Auth Client for Gear, Wear, Android” was created in 2018, has the same functionality as “Client for Google Authenticator with Companion”, but in addition, it also supports Android’s Wear devices. Use this app if you have Gear S2, S3, Sport or Galaxy, and need support for Android Wear or Fitbit watches as well. It’s free in Samsung store, but GACW companion will cost you $2 in Play Store, so in the end the price is the same as for other two.
- All Android Phones with Android version 6 and higher should be supported
- iPhones are not supported and there is no plans to support it in the future
The following Gear devices are supported:
- Gear S2
- Gear S3
- Gear Sport
The following Fitbit devices are supported:
Theoretically, all Android Wear devices should be supported by GACW as well. Since there are too many of different models in this category, we were not able to test all of them, so if you see any problem with your specific Wear watch model, please provide device details to us and we’ll try to fix.
The minimum Android version to run the companion app is Android 6.0
- Android application can be downloaded from Play Store: GAC or GACW
- The most universal way of installing GAC application on Gear device is through Samsung’s Android Gear App: Gear App. To install GACW on your Wear watch, use Android’d Wear OS app.
- If you browsing apps from a Samsung’s Galaxy device, you can also try a direct link for GAC, but it doesn’t work in all browsers even on Galaxy devices:
Why Updating Old App Not Possible in Samsung Store
The old GAC app supports many legacy Gear devices such as Gear, Gear II, Gear Neo, and Gear S. Since all these devices are different, they require different binaries. Samsung App Store doesn’t allow mixing companion and non-companion binary types in a single app’s distribution. That’s why new app is needed to enable companion functionality. We will gladly merge versions as soon as Samsung changes their policies (the best scenario) or when we decide to stop supporting legacy devices.
Below is an error message, which is caused by an attempt to add a companion-based binary to the old non-companion style app
Adding New Account from Android on Gear or Galaxy
To add a new account from the phone you’ll need to select “Connect to Phone” menu on Gear first:
Pic 1. Menu Page on Gear
If the device is already paired with and connected to the phone through Bluetooth, an icon on the top will turn green and you’ll see the following message:
Pic 2. Gear Connected to Phone
At this point an account page should popup on the phone automatically. You can either select an existing account or tap “+” button to add a new one. Selecting ‘+’ button will bring you to Scanner page. Now you can point the phone’s camera to a QR bar code. When QR bar code is recognized, the blue border will be blinking and a scanned code will show up in an edit box located just above the camera window.
Press “Send to Gear” button and the scanned account will be sent to your Gear device. You can also save the account to phone by pressing “Save” button. After an account is saved, the “Accounts” page will be displayed. Alternatively, you can get there by pressing an “Accounts” menu in the toolbar.
At the “Accounts” page you could see a list of OTP tokens for all your accounts, and you can use the buttons on the bottom to perform the following actions (left to right):
- Send selected accounts to Gear
- Save all accounts to a backup file
- Delete selected accounts from your phone
- Restore all accounts from a backup
- Add more accounts by either scanning QR bar code or by typing a shared secret manually
Tap a token if you want to zoom it. The token will be refreshed properly in the zoomed view as well. When a color of the border becomes red, a new token will be generated automatically.
You can scroll accounts on this page using left and right arrow buttons on the bottom.
Changing Account’s Order
By default the accounts are stored in an alphabetic order, but it’s possible to change the order by long pressing an account name and dragging it to the new place.
Tap an account name in the list to edit it. It will bring you to the Scanner page where you can edit account name, the bar code, or scan the code using the phone’s camera. Press store icon on the bottom to save the account to the phone.
Backing up and Restoring Accounts on Phone
Account restore page can be reached by tapping restore button (second from the right) on Accounts page.
Pic 6. Backup and Restore
By default, restore logic will use an encrypted backup and password will be required to decrypt the accounts and to verify a signature created by a backup. You can use plain unencrypted backup by checking “Don’t use encryption” switch, but that option is strongly discouraged. If you want your app to remember the password, use “Remember password” switch.
A button located in the right part of “Accts on Gear” box could be used to restore phone’s accounts directly from a gear device.
The backups that are not needed anymore can be deleted by selecting them in the backup list and pressing a “trash” button on the bottom.
Saving accounts to a backup file is similar and has two options as well: encrypted and unencrypted backups.
Google Drive can be used to backup and restore accounts as well. Use Google Drive button with a question mark to check what backups are available.
Legacy Backup and Restore
Legacy backup and restore are used to save or restore data in gac-codes.mp3 file that can be used for integrating with an older Gear’s GAC version that doesn’t have an Android’s companion app. Use either MP3 button on the bottom or Legacy Backup/Restore menu items in tool bar to create a backup or restore your accounts from it. The MP3 file will be created in Music directory that can be used by Samsung’s Gear App for transferring it further to your Gear device, where the file can be used to initialize the accounts through “Init from File” menu.
Messages Seeing on Gear
When accounts are successfully received by Gear you’ll see the following screen:
Pic 7. Accounts Received from Phone
When messages are sent by Gear to phone, you’ll see the confirmation screen:
Pic 8. Accounts Sent to Phone
If Gear is disconnected from its peer, the green icon will turn red.
Pic 9. No Connection Page
The Token/OTP page can be reached by tapping an account name on menu screen.
Pic 10. Token Page
GAC widget can be used to see the last viewed account and is activated in the same way as any other Gear’s widget: you add it on home screen selecting and tapping the icon below (just swipe screens left until you see it).
Pic. 11 Adding GAC Widget
After widget is added and if a user had recently viewed an account in the GAC app, the latter account will be displayed in the widget. If there was no account previously selected by a user, the following screen will show up.
Pic. 12 Non-initialized Widget
Tap the widget to initialize it or if you want to change a previously selected account. After an account is selected, the widget will display it until another account is selected.
Pic. 13 Initialized Widget
Navigate to the home screen and slide screens left to see the GAC widget.
Adding New Account from Android on Wear
First, start GACW app on Android phone, then start the same on your Wear watch. The beacon icon will turn green on the watch and Wear OS icon will show up in phone’s app tool bar.
Select accounts on your phone and press a “Send to Watch” button or menu item. After accounts are transferred, the Android app is not needed anymore. You’ll see an account list on your Wear device:
Pic. 14 Account list on Wear
Now you can select an account from the list to see the token:
Pic. 14 Auth Token on Wear
Google Auth for Fitbit
The following Fitbit devices have been tested:
- Fitbit Versa (real device)
- Fitbit Ionic (through simulator only)
Installing Google Auth on Fitbit
Fitbit app is approved and is available in the official Fitbit Store. To find and install it:
- Open Fitbit App on Android phone
- Tap Apps icon and type “Google Auth” to a search bar
- Open Fitbit App on Android and make sure that your Fitbit device is visible
- Open GACW App on Android. This step could be optional if you don’t mind typing your accounts manually
- Open Google Auth app on Fitbit device
The following screen will popup on Fitbit device:
Pic. 15 No Accounts Screen
4. To quickly check if the app is functional, click top-left button. It will import a testing account from settings:
Pic. 16 Account Received
5. Press green Ok button on the right and you’ll see an account list:
Pic. 17 Account LIst
6. Tap “Test” item to see a token:
Pic. 18 Test Token
7. If everything worked as described above, you can proceed to creating your own accounts. There are two ways of doing this: using GACW Android App and typing accounts manually in Fitbit’s Android App settings.
Creating Accounts Using GACW Phone App
- Open GACW, Android Fitbit App, Google Auth on Fitbit device
- Go to accounts page on Fitbit device and press beacon icon (top-right button)
- Device pairing dialogs will show on Fitbit and GACW:
Pic. 19 Pairing
4. Enter PIN from Fitbit to GACW and press enter. If paring is successful, you’ll see a confirmation message
5. Choose Ok button on Fitbit and GACW to close dialogs.
6. Beacon icon should be green on Fitbit’s accounts page. Fitbit icon will show up in GACW’s toolbar and “send to watch” button on the bottom-left will turn green. Select account that you want to transfer and press low left button on GACW to send them to Fitbit. If transfer is successful, you’ll see “accounts received” message on Fitbit.
Pic. 20 Accounts in GACW
7. Tap an account on Fitbit to see a token
Creating Accounts Manually
For each account that you want to create you’ll need:
- Arbitrary account name, e.g. “Google”;
- Shared secret in Base32 form.
- In Android’s Fitbit App find Google Auth and open its settings:
Pic. 21 Accounts in Fitbit’s Settings
2. Tap “Add Account” link and add a new account in the form: Account:SharedSecret. Make sure that there is no any errors in “Errors” section below.
Pic. 22 Settings Page
3. On Fitbit’s device tap left-top button to import accounts from setting. An “accounts received” page will show up if import is successful.
Pic. 23 Accounts Page
Issues that have been fixed
- An issue specific to Android 8.0 has been identified: the Android companion crashes with a Runtime Exception. The issue was attributed to the “new behavior” of Android 8.0 and is considered by many as a platform bug: https://stackoverflow.com/questions/48072438/java-lang-illegalstateexception-only-fullscreen-opaque-activities-can-request-o. That issue has been fixed in GAC version 3.4.1. Please report if you still see this problem.
- Progress bar might not work correctly on some older Android’s phone models: it didn’t go all the way to the end and didn’t refresh the tokens. The issue has been fixed in GAC version 3.4.0.
- There was a complain that camera can’t scan QR code on Pixel 2. Unfortunately, no details have been provided. Research has shown that Pixel 2 had many problems with camera in other apps as well. One suggestions was to use 16:9 resolution, which I did for Pixel2 and Pixel 2 XL devices only. Try Android’s version 3.4.5+ and let me know if it works. A ticket was opened with Google to investigate the issue, but they are very slow and I don’t have any confidence that they will ever find or fix it: https://issuetracker.google.com/issues/77754219.
Note: The latest message from Google was that it does work on Pixel and other Google devices. If you still have problems with those, please provide details.
- No support for Lollipop and lower versions. I’ve created a debug version for Lollipop. Try it and let me know if it works. If it doesn’t, please provide details and a log file (adb logcat -d >log.txt). You can install it from here: http://credelius.com/credelius/app-debug.apk (simply click on the link from your phone’s browser). You’ll need to enable install from 3rd parties to make it work: Settings->Security->Unknown Sources. I’ll merge that version with the main branch if see a need for Lollipop and a positive feedback. So far I’ve seen only one user who wanted it.
Under Investigation (happens rarely)
- Sometimes tapping on GAC widget doesn’t start the GAC app. If you see “Launching app” message too long and nothing happens, just tap the widget again. The root cause of the problem has not been identified yet. It could be platform related.
- On a very rare occasion, GAC widget can stop working and won’t react on a tap. It’s not clear why it’s happening, and reproducing is not possible, since it’s a very rare event. A work around for now: long press the widget and remove it, then add again. We’ll fix as soon as find a reason. It could be platform related.