#156

Learning about the Doorkeeper gem and testing it for adding OAuth2 provider capabilities to Rails applications.

Notes

Doorkeeper is an oAuth2 provider built in Ruby:

• integrates with Ruby on Rails and Grape frameworks.
• requires Ruby Rails 5 or higher
• Supported features:
  • The OAuth 2.0 Authorization Framework
    • Authorization Code Flow
    • Access Token Scopes
    • Refresh token
    • Implicit grant
    • Resource Owner Password Credentials
    • Client Credentials
  • OAuth 2.0 Token Revocation
  • OAuth 2.0 Token Introspection
  • OAuth 2.0 Threat Model and Security Considerations
  • OAuth 2.0 for Native Apps
  • Proof Key for Code Exchange by OAuth Public Clients

Extensions:

• OpenID Connect extension
• JWT Token support
• Assertion grant extension
• I18n translations - adds translations for errors and administrative actions

Running the Samples

Doorkeeper Provider App

The Doorkeeper Demo Provider App is an example of an OAuth 2 provider using Doorkeeper gem, Rails 5.2 and Devise.

Grabbing the source and install:

$ git clone git://github.com/doorkeeper-gem/doorkeeper-provider-app.git
$ cd doorkeeper-provider-app
$ bundle

Seed the app with sample data:

$ bundle exec rake db:setup
warning: parser/current is loading parser/ruby26, which recognizes
warning: 2.6.6-compliant syntax, but you are running 2.6.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
Created database 'db/development.sqlite3'
Created database 'db/test.sqlite3'
Application:
name: Doorkeeper Sinatra Client
redirect_uri: https://doorkeeper-sinatra.herokuapp.com/callback
uid: YLnVhB2JHgzbFig8PoqYQgPGx2qICqDCmaBDVPIdZDY
secret: YWW2gABlgoj6xbNdlrXXF5CjSjvj-QCCLnJv5LCi6W8

Start the app with rails server and load localhost:3000:

Doorkeeper Sinatra Client

The Doorkeeper Demo Sinatra Client is an example of OAuth 2 client.

Grabbing the source and install:

git clone git://github.com/applicake/doorkeeper-sinatra-client.git
doorkeeper-sinatra-client
bundle

First, make sure the application is correctly registered in the provider, and get the keys. From http://localhost:3000/oauth/applications/1, the “confidential” application (used where the client secret can be kept confidential):

And creating another non-confidential version of the app (used by Native mobile apps and Single Page Apps where the client secret cannot be kept confidential)

Creating a .env file (automatically by the app) with required settings:

$ cat .env
PUBLIC_CLIENT_ID                 = "MzqP76I9zGAhEkEJTEdhwBmeqM7JQHwD_9VOsF6fbm8"
PUBLIC_CLIENT_REDIRECT_URI       = "KZSq1UWAnl78VeE7d_EsV6DRBJCv9Ec6AvY2Y0RCklk"
CONFIDENTIAL_CLIENT_ID           = "YLnVhB2JHgzbFig8PoqYQgPGx2qICqDCmaBDVPIdZDY"
CONFIDENTIAL_CLIENT_SECRET       = "YWW2gABlgoj6xbNdlrXXF5CjSjvj-QCCLnJv5LCi6W8"
CONFIDENTIAL_CLIENT_REDIRECT_URI = "http://localhost:9292/callback"
PROVIDER_URL = "http://localhost:3000"

Start the Sinatra app bundle exec rackup config.ru and load the app at localhost:9292:

Confidential Client Authentication

After clicking “Sign in on localhost”, I am redirected to the provider app and challenged to sign-in (because I have not done that yet):

Once signed-in, I must authorised the calling app:

Then returned to the calling app, successfully signed-in:

Public Client Authentication

After clicking “Sign in with the public client on localhost”, I am redirected to the provider app and challenged to sign-in (because I have not done that yet):

Once signed-in, I must authorised the calling app:

Then returned to the calling app, successfully signed-in:

Managing Authorized Applications

After the authentications performed above, I can see the authorized applications at http://localhost:3000/oauth/authorized_applications:

Doorkeeper Devise Client

The Doorkeeper Demo Devise Client is an example of a rails+devise+omniauth application that acts as an OAuth2 client.

Grabbing the source and install:

git clone git@github.com:doorkeeper-gem/doorkeeper-devise-client.git
doorkeeper-devise-client
bundle
bundle exec rake db:migrate

NB: due to the recent release of omniauth 2.0.0, devise and omniauth-auth dependencies are a bit broken. See https://github.com/heartcombo/devise/issues/5326. Temporarily just added a further constraint to the Gemfile:

gem "omniauth", ">= 1.9", "< 2"

The app needs to be registered in the provider as “confidential” and with a callback url with path component of /users/auth/doorkeeper/callback

Using these details to add a .env file for the application:

$ cat .env
DOORKEEPER_APP_ID = "b9wv3zaHtSFu0hNusqRppCLyg4BslVtcaEegGc-dANw"
DOORKEEPER_APP_SECRET = "LgF108FvuXqYAoKZK7esT96r4AWiAbCYuJvmYapRePE"
DOORKEEPER_APP_URL = "http://localhost:3000"

Start the app rails s -p 3232 and load the app at localhost:3232:

After clicking “Sign in with OAuth 2 provider”, I am redirected to the provider app and challenged to sign-in (because I have not done that yet):

Once signed-in, I must authorised the calling app:

Then returned to the calling app, successfully signed-in:

Building a Rails 6 App with OAuth Provider

Build a Skeleton Rails 6 App

Checking Pre-requisites and Installation

$ node -v
v12.8.0
$ npm -v
6.10.2
$ ruby -v
ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-darwin17]
$ sqlite3 --version
3.19.3 2017-06-27 16:48:08 2b0954060fe10d6de6d479287dd88890f1bef6cc1beca11bc6cdb79f72e2377b
$ gem install rails -v 6.1.1
...
$ rails --version
Rails 6.1.1

The basic app:

$ rails new demo-provider
...
$ cp .ruby-gemset demo-provider # to keep the app within the same gemset
$ cd demo-provider
$ rm -fR .git # --skip-git would do this, but also means no .gitignore generated

$ rails generate controller Welcome index
$ rails generate scaffold Article title:string text:text
$ rails db:migrate

Add the devise gem to the Gemfile and bundle install

$ rails generate devise:install
$ rails generate devise:views
$ rails generate devise User
$ rails db:migrate

Minimal customisation of the app:

• add before_action :authenticate_user! to the ArticlesController
• add root 'welcome#index' to routes.rb
• add sign in/out links to application.html.erb

Basic app is working:

Adding doorkeeper:

$ bundle add doorkeeper
bundle exec rails generate doorkeeper:install

Configure resource_owner_authenticator block for devise auth in config/initializers/doorkeeper.rb.

Choose ActiveRecord as the ORM:

rails generate doorkeeper:migration
rails db:migrate

Add some links to the application layout:

Testing with the Doorkeeper Devise Client

Add the scopes to config/initializers/doorkeeper.rb that are expected by the Doorkeeper Devise Client:

default_scopes :read
optional_scopes :write

Add support for /api/v1/me.json

Register the “Doorkeeper Devise Client” as a new client application:

Update the doorkeeper-devise-client .env file with these settings:

$ cat .env
DOORKEEPER_APP_ID = "OmTd4AwOdyGtSjax0EM41Q92aAjTLoPLB4shbT5ItqI"
DOORKEEPER_APP_SECRET = "9v2Ys2ZYZGZ4lMqWJqUU6l3DHrIiP0uY80_2R1qpsbk"
DOORKEEPER_APP_URL = "http://localhost:3000"

Startup the doorkeeper-devise-client app rails s -p 3232 and load it at localhost:3232.

OAuth signs in successfully:

Credits and References

• Doorkeeper Guides
• doorkeeper - rubygems
• doorkeeper - github
• Doorkeeper Demo Provider App
• Doorkeeper Demo Sinatra Client
• Doorkeeper Demo Devise Client