A Devise extension to allow your app to utilise Google's 2FA Mobile app
Switch branches/tags
Pull request Compare This branch is 70 commits behind AsteriskLabs:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


Devise Google Authenticator

This is a devise extension to allow your app to utilise Google Authenticator for Time-based One Time Passwords (TOTP).


  • Version 0.1 - initial release, just to push it up, is still very early and requires a bit work

  • Version 0.2 - tidied up some of the code - changed the references to AsteriskLabs

  • Version 0.3 - first working version! With working generators, tests, and doesnt require changes to Devise's Sign In view

  • Version 0.3.1 - Slight updated in the dependencies.


Add the gem to your Gemfile (don't forget devise too):

  • gem 'devise', '~> 1.5.3'

  • gem 'devise_google_authenticator', '0.3.1'

Don't forget to “bundle install”

Automatic Installation (Lets assume this is a bare bones app)

Run the following generator to add the necessary configuration options to Devise's config file:

  • rails g devise_google_authenticator:install

After you've created your Devise user models (which is usually done with a “rails g devise MODEL”), set up your Google Authenticator additions:

  • rails g devise_google_authenticator MODEL

Don't forget to migrate:

  • rake db:migrate

Configuration Options

The install generator adds some options to the end of your Devise config file (config/initializers/devise.rb)

  • config.ga_timeout - how long should the user be able to authenticate with their Google Authenticator token

  • config.ga_timedrift - a multiplier which provides for drift between a user's clock (and therefore their OTP) and the system clock. This should be fine at 3.

Custom Views

If you want to customise your views (which you likely will want to, as they're pretty ugly right now), you can use the generator:

  • rails g devise_google_authenticator:views


With this extension enabled, the following is expected behaviour:

  • When a user registers, they are forwarded onto the Display QR page. This allows them to add their new “token” to their mobile device, and enable, or disable, the functionality.

  • If users can't self-register, they're still able to visit this page by visiting /MODEL/displayqr (eg: /users/displayqr).

  • If the function is enabled (for that user), when they sign in, they'll be prompted for their password (as per normal), but then redirected into the Check QR page. They have to enter their token (from their device) to then successfully authenticate.


The install generator also installs an english copy of a Devise Google Authenticator i18n file. This can be modified (or used to create other language versions) and is located at: config/locales/devise.google_authenticator.en.yml

Thanks (and unknown contributors)

This extension would not exist without the following other projects and associated authors (Whom I have turned to for inspiration and definitely have helped contributing by providing awesome Devise extensions. A lot of this code has been refactored from various sources, in particular these - in particular Sergio and Devise_invitable for his excellent unit test code):

Contributing to devise_google_authenticator

  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet

  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it

  • Fork the project

  • Start a feature/bugfix branch

  • Commit and push until you are happy with your contribution

  • Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.

  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.


Copyright © 2012 Christian Frichot. See LICENSE.txt for further details.