4.6 KiB
Two factor authentication for Devise
Features
- control sms code pattern
- configure max login attempts
- per user level control if he really need two factor authentication
- your own sms logic
Configuration
Initial Setup
In a Rails environment, require the gem in your Gemfile:
gem 'two_factor_authentication'
Once that's done, run:
bundle install
Automatic installation
In order to add two factor authorisation to a model, run the command:
bundle exec rails g two_factor_authentication MODEL
Where MODEL is your model name (e.g. User or Admin). This generator will add :two_factor_authenticatable to your model
and create a migration in db/migrate/, which will add :otp_secret_key and :second_factor_attempts_count to your table.
Finally, run the migration with:
bundle exec rake db:migrate
Add the following line to your model to fully enable two-factor auth:
has_one_time_password
Set config values, if desired, for maximum second factor attempts count, allowed time drift, and OTP length.
config.max_login_attempts = 3
config.allowed_otp_drift_seconds = 30
config.otp_length = 6
Override the method to send one-time passwords in your model, this is automatically called when a user logs in:
def send_two_factor_authentication_code
# use Model#otp_code and send via SMS, etc.
end
Manual installation
To manually enable two factor authentication for the User model, you should add two_factor_authentication to your devise line, like:
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable, :two_factor_authenticatable
Add the following line to your model to fully enable two-factor auth:
has_one_time_password
Set config values, if desired, for maximum second factor attempts count, allowed time drift, and OTP length.
config.max_login_attempts = 3
config.allowed_otp_drift_seconds = 30
config.otp_length = 6
Override the method to send one-time passwords in your model, this is automatically called when a user logs in:
def send_two_factor_authentication_code
# use Model#otp_code and send via SMS, etc.
end
Customisation and Usage
By default second factor authentication enabled for each user, you can change it with this method in your User model:
def need_two_factor_authentication?(request)
request.ip != '127.0.0.1'
end
this will disable two factor authentication for local users
This gem is compatible with Google Authenticator (https://support.google.com/accounts/answer/1066447?hl=en). You can generate provisioning uris by invoking the following method on your model:
user.provisioning_uri #This assumes a user model with an email attributes
This provisioning uri can then be turned in to a QR code if desired so that users may add the app to Google Authenticator easily. Once this is done they may retrieve a one-time password directly from the Google Authenticator app as well as through whatever method you define in send_two_factor_authentication_code
Overriding the view
The default view that shows the form can be overridden by first adding a folder named: "two_factor_authentication" inside "app/views/devise", in here you want to create a "show.html.erb" view.
The full path should be "app/views/devise/two_factor_authentication/show.html.erb"
<h2>Hi, you received a code by email, please enter it below, thanks!</h2>
<%= form_tag([resource_name, :two_factor_authentication], :method => :put) do %>
<%= text_field_tag :code %>
<%= submit_tag "Log in!" %>
<% end %>
<%= link_to "Sign out", destroy_user_session_path, :method => :delete %>
Updating existing users with OTP secret key
If you have existing users that needs to be provided with a OTP secret key, so they can take benefit of the two factor authentication, create a rake. It could look like this one below:
desc "rake task to update users with otp secret key"
task :update_users_with_otp_secret_key => :environment do
users = User.all
users.each do |user|
key = ROTP::Base32.random_base32
user.update_attributes(:otp_secret_key => key)
user.save
puts "Rake[:update_users_with_otp_secret_key] => User '#{user.email}' OTP secret key set to '#{key}'"
end
end