Quo Vadis

Multifactor authentication for your Rails app (Rails 7 and Rails 6).

Designed in accordance with the OWASP Application Security Verification Standard and relevant OWASP Cheatsheets.

Simple to integrate into your application. The main task is customising the example views' markup to match your look-and-feel.

• Works with any model, e.g. User or Person.
• Works with multiple models, e.g. User and Admin.
• Works with any identifier, e.g. :username or :email.
• Minimal footprint in your models and controllers.
• Does not touch your existing database tables.
• Secrets (password, TOTP secret, 2FA recovery codes) are encrypted at rest.

• Authentication by password.
• Two-factor authentication (2FA) by TOTP with recovery codes as a backup factor. Can be optional or mandatory.
• Change password.
• Reset password.
• Account confirmation (a.k.a. email verification) (optional).
• OTPs (account confirmation, password reset), TOTPs, and recovery codes are all one-time-only.
• Sessions expired after lifetime or idle time exceeded.
• Session replaced after any privilege change.
• View active sessions, log out of any of them.
• Email-notifications of updates to authentication details.
• Audit trail.

• Can shortcut logging in for speedier tests.

Add the gem to your Gemfile:

bundle add 'quo_vadis'

Next, add the database tables:

rails quo_vadis:install:migrations && rails db:migrate

All the database tables are prefixed with qv_.

Finally, copy the example views across:

rails generate quo_vadis:install

Your model must have an :email attribute. All authentication-related emails will be sent to this address.

Your model must have an identifier, e.g. :email (default) or :username, with a uniqueness validation.

All you need do is add a call to authenticates, somewhere after your identifier's uniqueness validation.

For example, let's say you have a User model and the identifier is :email:

class User < ApplicationRecord
  validates :email, uniqueness: {case_sensitive: false}
  authenticates
end

If instead you had a Person model with a :username identifier:

class Person < ApplicationRecord
  validates :username, uniqueness: {case_sensitive: false}
  authenticates identifier: :username
end

You can create and update your models as before. When you want to set a password for the first time, just include :password and, optionally, :password_confirmation in the attributes to #create or #update.

If you want to change an existing password, use the Change Password feature. If you update a model (that already has a password) with a :password attribute, it will raise a QuoVadis::PasswordExistsError.

The minimum password length is configured by QuoVadis.password_minimum_length (12 by default).

You can use these methods in your controllers.

Use this to restrict actions to password-authenticated users. It is aliased to :require_authentication for convenience.

class FoosController < ApplicationController
  before_action :require_password_authentication
end

Use this to restrict actions to users authenticated with both a password and a second factor. (You do not need to use :require_password_authentication for these actions.)

class BarsController < ApplicationController
  before_action :require_two_factor_authentication
end

Use this to log in a user who has authenticated with a password. For the optional browser_session argument, pass true to log in for the duration of the browser session, or false to log in for QuoVadis.session_lifetime (which could be the browser session anyway). Any metadata are stored in the log entry for the login.

Call this to get the authenticated user. Feel free to alias this to :current_user or set it into an ActiveSupport::CurrentAttributes class.

Available in controllers and views.

Call this to find out whether a user has authenticated with a password.

Available in controllers and views.

You can use routing constraints to restrict routes to logged-in or logged-out users. For example:

Rails.application.routes.draw do
  constraints(QuoVadis::Constraints::LoggedOut) do
    root "pages#index"
  end

  constraints(QuoVadis::Constraints::LoggedIn) do
    root "dashboard#show", as: :dashboard
  end
end

You can use authenticated_model and logged_in? in your views. For example:

<% if logged_in? %>
  <%= link_to 'My profile', authenticated_model %>
<% end %>

In your own views, you must prefix QuoVadis's routes with quo_vadis.. For example:

link_to 'Log in', quo_vadis.login_path

When you are customising QuoVadis's views, you must prefix your app's routes with main_app.. For example:

link_to 'Home', main_app.root_path

The example views show the forms and fields you need. You should only need to adapt the markup to suit your app's appearance.

In the snippets below we assume a User model whose identifier is :email. You can of course use anything you like.

Your new user sign-up form (example) must include:

• a :password field;
• optionally a :password_confirmation field;
• a field for their identifier;
• an :email field if the identifier is not their email.

In your controller, use the #login method to log in your new user. The optional second argument specifies for how long the user should be logged in, and any metadata you supply is logged in the audit log.

After logging in the user, redirect them wherever you like. You can use qv.path_after_signup which resolves to the first of these routes that exists: :after_signup, :after_login, the root route.

class UsersController < ApplicationController
  def create
    @user = User.new user_params
    if @user.save
      login @user
      redirect_to qv.path_after_signup
    else
      # ...
    end
  end

  private

  def user_params
    params.require(:user).permit(:name, :email, :password, :password_confirmation)
  end
end

# config/routes.rb
get '/dashboard', as: 'after_login'

Follow the steps above for sign-up.

After you have logged in the user and redirected them (to any page which requires being logged in), QuoVadis detects that they need to confirm their account. QuoVadis emails them a 6-digit confirmation code and redirects them to the confirmation page where they can enter that code.

The confirmation code is valid for QuoVadis.account_confirmation_otp_lifetime.

Once the user has confirmed their account, they will be redirected to qv.path_after_signup which resolves to the first of these routes that exists: :after_signup, :after_login, the root route. Add whichever works best for you.

You need to write the email view (example). It must be in app/views/quo_vadis/mailer/account_confirmation.{text,html}.erb and output the @otp variable. See the Configuration section for how to set QuoVadis's emails' from addresses, headers, etc.

Now write the confirmation page where the user types in the confirmation code from the email (example). It must be in app/views/quo_vadis/confirmations/new.html.:format and must POST the otp field to confirm_path. You can provide a button to send a new confirmation code (perhaps the original email didn't arrive, or the user didn't have time to act on it before it expired) – it should POST to send_confirmation_path.

If the user closes their browser after signing up but before they have confirmed their account, when they next access a page which requires being logged in they will be sent a new confirmation code and redirected to the confirmation page, as if they had just signed up.

Use before_action :require_password_authentication or before_action :require_authentication in your controllers.

Write the login view (example). Your login form must be in app/views/quo_vadis/sessions/new.html.:format. Note it must capture the user's identifier (not email, unless the identifier is email).

If you include a remember checkbox in your login form:

• if the user checks it, they will be logged in for QuoVadis.session_lifetime;
• if the user does not check it, they will be logged in for the browser session.

If you do not include a remember checkbox, the user will be logged in for QuoVadis.session_lifetime.

After authenticating the user will be redirected to the first of these that exists:

• the page they tried to view before they were redirected to the login page;
• a route named after_login, if any;
• your root route.

Send a DELETE request to quo_vadis.logout_path. For example:

button_to 'Log out', quo_vadis.logout_path, method: :delete

Note you are responsible for removing any application session data you want removed. To do so, subclass QuoVadis::SessionsController and override the destroy method:

# app/controllers/custom_sessions_controller.rb
class CustomSessionsController < QuoVadis::SessionsController
  def destroy
    reset_session
    super
  end
end

Add a route:

# config/routes.rb
delete 'logout', to: 'custom_sessions#destroy'

And then point your log out button at your custom action:

button_to 'Log out', main_app.logout_path, method: :delete

If you do not want 2FA at all, set QuoVadis.two_factor_authentication_mandatory false in your configuration and skip the rest of this section.

If you do want 2FA, you can choose whether it is mandatory or optional for your users by setting QuoVadis.two_factor_authentication_mandatory <true|false> in your configuration.

Use before_action :require_two_factor_authentication in your controllers (which supersedes :require_password_authentication). This will require the user, after authenticating with their password, to authenticate with 2FA – when 2FA is mandatory, or when it is optional and the user has set up 2FA.

Here's the workflow for a user setting up optional 2FA:

1. User visits their 2FA overview page.
2. [2FA overview page] User clicks a link to set up 2FA (TOTP for now).
3. [TOTP setup page] User scans the QR code with their authenticator and enters the 6-digit one-time password.
4. QuoVadis verifies the one-time password, generates 5 backup recovery codes, and redirects the user to the recovery codes page (or back to step 3 if the OTP is invalid).
5. [Recovery code page] User views and hopefully saves their 5 recovery codes.

When 2FA is mandatory the workflow starts automatically at step 3 after password authentication.

In your views, have a link where users can manage their 2FA:

link_to '2FA', quo_vadis.twofa_path

Write the 2FA overview page (example). It must be in app/views/quo_vadis/twofas/show.html.:format. This page allows the user to set up 2FA, deactivate or reset it, and generate new recovery codes.

Next, write the TOTP setup page (example). It must be in app/views/quo_vadis/totps/new.html.:format. This page shows the user a QR code (and the key as text) which they scan with their authenticator.

Next, write the recovery codes page (example). It must be in app/views/quo_vadis/recovery_codes/index.html.:format. This shows the recovery codes immediately after TOTP is setup, and immediately after generating fresh recovery codes, but not otherwise.

Next, write the TOTP challenge page where a user inputs their 6-digit TOTP (example). It must be in app/views/quo_vadis/totps/challenge.html.:format. It's a good idea to link to the recovery code page (challenge_recovery_codes_path) for any user who has lost their authenticator.

Finally, write the recovery code challenge page where a user inputs one of their recovery codes (example). It must be in app/views/quo_vadis/recovery_codes/challenge.html.:format. A recovery code can only be used once, and using one deactivates TOTP – so the user will have to set it up again next time.

To change their password, the user must provide their current one as well as the new one.

Write the change-password form (example). It must be in app/views/quo_vadis/passwords/edit.html.:format.

After the password has been changed, the user is redirected to the first of:

• your route named :after_password_change, if any;
• your root route.

A successful password change logs out any other sessions the user has (e.g. on other devices).

The user can reset their password if they lose it and cannot log in. The flow is:

1. [Request password-reset page] User enters their identifier (not their email unless the identifier is email).
2. QuoVadis emails the user a 6-digit reset code, which is valid for QuoVadis.password_reset_otp_lifetime, and redirects to the password-reset page.
3. [The email] The user reads the code.
4. [Password-reset page] The user enters the 6-digt code and their new password and clicks the save button.
5. QuoVadis sets the user's password and logs them in.

First, write the page where the user requests a password-reset (example). It must be in app/views/quo_vadis/password_resets/new.html.:format. It must POST the user's identifier (not email, unless the identifier is email) to password_reset_path.

Now write the email view (example). It must be in app/views/quo_vadis/mailer/reset_password.{text,html}.erb and output the @otp variable. See the Configuration section for how to set QuoVadis's emails' from addresses, headers, etc.

Now write the page where the user types in the reset code from the email and their new password (example). It must be in app/views/quo_vadis/password_resets/edit.html.:format and must PUT the otp, password, and password_confirmation fields to password_reset_path.

After the user has reset their password, they will be logged in and redirected to the first of these that exists:

• a route named :after_login;
• your root route.

When the user resets their password, they are logged out of any other sessions they may have, for example on other devices.

A logged-in session lasts for either the browser session or QuoVadis.session_lifetime. As well as having a lifetime, a session will also expire after it has been inactive for QuoVadis.session_idle_timeout.

A user can view their active sessions and log out of any of them.

Write the view showing the sessions (example). It must be in app/views/quo_vadis/sessions/index.html.:format.

An audit trail is kept of authentication events. You can see the full list in the Log class.

Write the view showing the events (example). It must be in app/views/quo_vadis/logs/index.html.:format.

QuoVadis notifies users by email whenever their authentication details are changed or something suspicious happens.

Write the corresponding mailer views:

• change of email (example)
• change of identifier (unless the identifier is email) (example)
• change of password (example)
• reset of password (example)
• TOTP setup (example)
• TOTP code used a second time (example)
• 2FA deactivated (example)
• recovery codes generated (example)

They must be in app/views/quo_vadis/mailer/NAME.{text,html}.erb.

You can revoke a user's access by calling #revoke_authentication_credentials on the model instance. This deletes the user's password, TOTP credential, recovery codes, and active sessions. Their authentication logs, or audit trail, are preserved.

Instead of going through your login page to log in before every test, you can tell QuoVadis which model to authenticate as when visiting the first URL in your test.

Use a login param pointing to your model's global ID. Note that the model must be able to log in normally, i.e. it must have a password (and therefore a qv_account).

For example:

@user = User.create(email: '...', password: '...')
visit dashboard_path(login: @user.to_global_id)

This only works in the test environment.

This is QuoVadis' default configuration:

QuoVadis.configure do
  password_minimum_length               12
  mask_ips                              false
  cookie_name                           (Rails.env.production? ? '__Host-qv' : 'qv')
  session_lifetime                      :session
  session_lifetime_extend_to_end_of_day false
  session_idle_timeout                  :lifetime
  password_reset_otp_lifetime           10.minutes
  accounts_require_confirmation         false
  account_confirmation_otp_lifetime     10.minutes
  mail_headers                          ({ from: 'Example App <support@example.com>' })
  enqueue_transactional_emails          true
  app_name                              Rails.app_class.to_s.deconstantize  # for the TOTP QR code
  two_factor_authentication_mandatory   true
  mount_point                           '/'
end

You can override any of it with a similarly structured file in config/initializers/quo_vadis.rb.

Here are the options in detail:

The minimum number of characters for a password.

Whether to mask the IP address in the sessions list and the audit trail.

Masking means setting the last octet (IPv4) or the last 80 bits (IPv6) to 0.

The name of the cookie QuoVadis uses to store the session identifier. The __Host- prefix is recommended in an SSL environment (but cannot be used in a non-SSL environment).

The lifetime of a logged-in session. Use :session for the browser session, or a Duration or number of seconds.

Whether to extend the session's lifetime to the end of the day it will expire on.

Set true to reduce the chance of a user being logged out while actively using your application.

The logged-in session is expired if the user isn't seen for this Duration or number of seconds. Use :lifetime to set the idle timeout to the session's lifetime (i.e. to turn off the idle timeout).

The Duration or number of seconds for which a password-reset code is valid.

Whether new users must confirm their account before they can log in.

The Duration or number of seconds for which an account-confirmation code is valid.

The class from which QuoVadis's mailer inherits.

Mail headers which QuoVadis' emails should have.

Set true if account-confirmation and password-reset emails should be queued for later delivery (#deliver_later) or false if they should be sent inline (#deliver_now).

Used in the provisioning URI for the TOTP QR code.

Whether users must set up and use a second authentication factor.

The path prefix for QuoVadis's routes.

For example, the default login path is at /login. If you set mount_point to /auth, the login path would be /auth/login.

You must also configure the mailer host so URLs are generated correctly in emails:

config.action_mailer.default_url_options: { host: 'example.com' }

You can specify QuoVadis's controllers' layouts in a #to_prepare block in your application configuration. For example:

# config/application.rb
module YourApp
  class Application < Rails::Application
    config.to_prepare do
      QuoVadis::ConfirmationsController.layout 'your_layout'
    end
  end
end

You can set up your post-signup, post-authentication, and post-password-change routes. If you don't, you must have a root route. For example:

# config/routes.rb
get '/signups/confirmed', to: 'dashboards#show', as: 'after_signup'
get '/dashboard',         to: 'dashboards#show', as: 'after_login'
get '/profile',           to: 'profiles#show',   as: 'after_password_change'

All QuoVadis' flash messages are set via i18n.

You can override any of the messages with your own locale file at config/locales/quo_vadis.en.yml.

If you don't want a specific flash message at all, give the key an empty value in your locale file.

Copyright Andrew Stewart (boss@airbladesoftware.com).

Released under the MIT licence.