This is an OmniAuth strategy for authenticating with MYDIGIPASS.COM.

If you want to integrate your website with MYDIGIPASS.COM, you will need to sign up on developer.mydigipass.com and create an application. Checkout our Getting Started Guide for step by step instructions of setting up your application. You will get a client_id and client_secret you need to fill in here.

It is recommended to use the OAuth state parameter to prevent CSRF attacks. Omniauth actually enables this behaviour by default. Usage of the state parameter is illustrated in the example app.

Initialize the strategy as follows:

use OmniAuth::Builder do
  provider :mydigipass, ENV['MYDIGIPASS_CLIENT_ID'], ENV['MYDIGIPASS_CLIENT_SECRET']
end

Add an initializer mydigipass.rb containing your application specific configuration. Testing on your local machine is possible using a localhost redirect URI.

# MYDIGIPASS.COM OAuth configuration

MDP_JS_SRC="https://static.mydigipass.com/en/dp_connect.js"

MDP_CLIENT_ID="<your-production-client-id>"
MDP_CLIENT_SECRET="<your-production-client-secret>"

if Rails.env.production?
  MDP_CALLBACK_URL="<your-production-base-url>/auth/mydigipass/callback"
else
  MDP_CALLBACK_URL="http://localhost:3000/auth/mydigipass/callback"
end

Inside your config/application.rb add the following (e.g. at the bottom, inside the configuration block) :

# enable omniauth strategies
Rails.application.config.middleware.use OmniAuth::Builder do
  provider :mydigipass, MDP_CLIENT_ID, MDP_CLIENT_SECRET
end

And then you just have to make sure you have something listening at /auth/:provider/callback. Suppose you add the following routes:

match '/auth/:provider/callback', :to => 'home#auth_create'
match '/auth/failure', :to => 'home#auth_failure'

On the login page and/or signup page, you can show the MYDIGIPASS.COM button as follows:

= link_to("connect with mydigipass.com", "#", :class => "dpplus-connect",
                                              :"data-is-sandbox" => true,
                                              :"data-client-id" => MDP_CLIENT_ID,
                                              :"data-redirect-uri" => MDP_CALLBACK_URL,
                                              :"data-state" => @state)

and also include the dp_connect.js Javascript file:

%script{:type => 'text/javascript', :src => MDP_JS_SRC}

Since you can potentially link a MYDIGIPASS.COM account to an existing account on your site, you have to protect against CSRF attacks. For this reason, every time you render a view with the above link, you have to generate a new random CSRF-protection state token. This token must be stored in two places:

1. in the data-state attribute of the link itself (see above code),
2. in the omniauth.state session variable.

To generate a suitable token, you can put the following code in the controller action or even in the view itself:

@state = session['omniauth.state'] = SecureRandom.hex(24)

When Omniauth is processing the OAuth call, it will compare the state parameter passed back in by MIDIGPASS.COM to the omniauth.state parameter stored in the user's session. If the tokens do not match, Omniauth will conclude that the authentication was originally initiated in another browser session and abort the remainder of the flow.

Note: If you use the state parameter for CSRF protection, you must register a separate autoconnect URL (which is usually the URL of the login page of your application) with MYDIGIPASS.COM to enable users to sign in from our launchpad.

To handle the actual callback, you can use something like the following auth_create implementation inside your HomeController:

def auth_failure
  set_flash_message(:notice, "OAuth error: #{params[:message]}")
  redirect_to root_path
end

def auth_create
  user = User.find_or_create_from_auth_hash(request.env['omniauth.auth'].with_indifferent_access)
  logger.debug "Found or created user: #{user.email} [#{user.id}]"
  if user.sign_in_count == 0
    set_flash_message(:notice, "Welcome #{user.email}, thank you for signing up using your dP+ account!")
  else
    set_flash_message(:notice, "Succesfully logged in!")
  end
  sign_in(:user, user, :bypass => true)
  redirect_to dashboard_path
end

When a user signs in through MYDIGIPASS.COM, it could be a new user (signing up), or an existing user. The function find_or_create_from_auth_hash handles that for me:

def self.find_or_create_from_auth_hash(auth_hash)
  logger.debug "User.find_or_create_from_auth_hash: auth_hash = #{auth_hash.inspect} "
  received_uuid = auth_hash[:extra][:raw_info][:uuid]
  received_email = auth_hash[:extra][:raw_info][:email]

  user = User.find_by_uuid(received_uuid) || User.find_by_email(received_email)
  user = user.nil? ? create_from_auth_hash(received_uuid, received_email) : prevent_login_with_normal_password(user, received_uuid)
end

Find the user, by uuid or email. If user is found by uuid, she has logged on before with MYDIGIPASS.COM. If a matching mail is found, link the uuid to that user. If user isn't found, create one with the given email and uuid.

Should users only be allowed to to login via MYDIGIPASS.COM, the other sign in method has to be disabled. This step is optional.

There is a small, fully working Sinatra based example application in the example folder. To make it work just type rackup in the folder.

Aside from signing in with MYDIGIPASS.COM, the example application also shows how to use the Connect API through a simple HTTParty wrapper that can be found in lib/mydigipass/connect_api.rb.

The Connect API and its purpose is described in more detail in the MDP Developer documentation.

Copyright (c) 2012 Nathan Van der Auwera

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.