OAuth Plugin¶ ↑

This is a plugin for implementing OAuth Providers and Consumers in Rails applications.

We support the revised OAuth 1.0a specs at:

tools.ietf.org/html/rfc5849

As well as support for OAuth 2.0:

tools.ietf.org/html/draft-ietf-oauth-v2-22

Find out more on the OAuth site at:

oauth.net

There are several changes to the latest OAuth 2.0 spec which requires a couple of changes to 2 models which you are REQUIRED to update manually if you are supporting OAuth2.

github.com/pelle/oauth-plugin/blob/master/lib/generators/active_record/oauth_provider_templates/oauth2_token.rb

class Oauth2Token < AccessToken
  attr_accessor :state
  def as_json(options={})
    d = {:access_token=>token, :token_type => 'bearer'}
    d[:expires_in] = expires_in if expires_at
    d
  end

  def to_query
    q = "access_token=#{token}&token_type=bearer"
    q << "&state=#{URI.escape(state)}" if @state
    q << "&expires_in=#{expires_in}" if expires_at
    q << "&scope=#{URI.escape(scope)}" if scope
    q
  end

  def expires_in
    expires_at.to_i - Time.now.to_i
  end
end

github.com/pelle/oauth-plugin/blob/master/lib/generators/active_record/oauth_provider_templates/oauth2_verifier.rb

class Oauth2Verifier < OauthToken
  validates_presence_of :user
  attr_accessor :state

  def exchange!(params={})
    OauthToken.transaction do
      token = Oauth2Token.create! :user=>user,:client_application=>client_application, :scope => scope
      invalidate!
      token
    end
  end

  def code
    token
  end

  def redirect_url
    callback_url
  end

  def to_query
    q = "code=#{token}"
    q << "&state=#{URI.escape(state)}" if @state
    q
  end

  protected

  def generate_keys
    self.token = OAuth::Helper.generate_key(20)[0,20]
    self.expires_at = 10.minutes.from_now
    self.authorized_at = Time.now
  end

end

There are matching specs for these which you may want to move into your project as well.

You need to install the oauth gem (0.4.4) which is the core OAuth ruby library. It will likely NOT work on any previous version of the gem.

gem install oauth

Add the plugin to your Gemfile:

gem "oauth-plugin", "~> 0.4.0"

And install it:

bundle install

The plugin can now be installed as an gem from github, which is the easiest way to keep it up to date.

gem install oauth-plugin --pre

You should add the following in the gem dependency section of environment.rb

config.gem "oauth"
config.gem "oauth-plugin"

Alternatively you can install it in vendors/plugin:

script/plugin install git://github.com/pelle/oauth-plugin.git

The Generator currently creates code (in particular views) that only work in Rails 2 and 3.

It should not be difficult to manually modify the code to work on Rails 1.2.x

I think the only real issue is that the views have .html.erb extensions. So these could theoretically just be renamed to .rhtml.

Please let me know if this works and I will see if I can make the generator conditionally create .rhtml for pre 2.0 versions of RAILS.

This currently supports rspec, test_unit, haml, erb, active_record and mongoid:

rails g oauth_provider

This generates OAuth and OAuth client controllers as well as the required models.

It requires an authentication framework such as acts_as_authenticated, restful_authentication or restful_open_id_authentication. It also requires Rails 2.0.

A big change over previous versions is that we now use a rack filter. You have to install this in your application.rb file:

require 'oauth/rack/oauth_filter'
config.middleware.use OAuth::Rack::OAuthFilter

The generator supports the defaults you have created in your application.rb file. eg:

config.generators do |g|
  g.orm             :mongoid
  g.template_engine :haml
  g.test_framework  :rspec
end

Add the following lines to your user model:

has_many :client_applications
has_many :tokens, :class_name => "OauthToken", :order => "authorized_at desc", :include => [:client_application]

While it isn’t very flexible at the moment there is an oauth_provider generator which you can use like this:

./script/generate oauth_provider

This generates OAuth and OAuth client controllers as well as the required models.

It requires an authentication framework such as acts_as_authenticated, restful_authentication or restful_open_id_authentication. It also requires Rails 2.0.

A big change over previous versions is that we now use a rack filter. You have to install this in your config/environment.rb file:

require 'oauth/rack/oauth_filter'
config.middleware.use OAuth::Rack::OAuthFilter

By default the generator generates RSpec and ERB templates. The generator can instead create Test::Unit and/or HAML templates. To do this use the following options:

./script/generate oauth_provider --test-unit --haml

These can of course be used individually as well.

Add the following lines to your user model:

has_many :client_applications
has_many :tokens, :class_name => "OauthToken", :order => "authorized_at desc", :include => [:client_application]

The database is defined in:

db/migrate/XXX_create_oauth_tables.rb

Run them as any other normal migration in rails with:

rake db:migrate

As the flow has changed slightly and there are a couple of database changes it isn’t as simple as just updating the plugin. Please follow these steps closely:

You need to add a migration:

script/generate migration upgrade_oauth

Make it look like this:

class UpgradeOauth < ActiveRecord::Migration
  def self.up
    add_column :oauth_tokens, :callback_url, :string
    add_column :oauth_tokens, :verifier, :string, :limit => 20
  end

  def self.down
    remove_column :oauth_tokens, :callback_url
    remove_column :oauth_tokens, :verifier
  end
end

There are changes to the following files:

app/models/client_application.rb
app/models/request_token.rb
app/controllers/oauth_controller.rb

Add the following towards the top of the model class

attr_accessor :token_callback_url

Then change the create_request_token method to the following:

def create_request_token
  RequestToken.create :client_application => self, :callback_url => token_callback_url
end

The RequestToken contains the bulk of the changes so it’s easiest to list it in it’s entirety. Mainly we need to add support for the oauth_verifier parameter and also tell the client that we support OAuth 1.0a.

Make sure it looks like this:

class RequestToken < OauthToken

  attr_accessor :provided_oauth_verifier

  def authorize!(user)
    return false if authorized?
    self.user = user
    self.authorized_at = Time.now
    self.verifier=OAuth::Helper.generate_key(16)[0,20] unless oauth10?
    self.save
  end

  def exchange!
    return false unless authorized?
    return false unless oauth10? || verifier == provided_oauth_verifier

    RequestToken.transaction do
      access_token = AccessToken.create(:user => user, :client_application => client_application)
      invalidate!
      access_token
    end
  end

  def to_query
    if oauth10?
      super
    else
      "#{super}&oauth_callback_confirmed = true"
    end
  end

  def oob?
    self.callback_url == 'oob'
  end

  def oauth10?
    (defined? OAUTH_10_SUPPORT) && OAUTH_10_SUPPORT && self.callback_url.blank?
  end

end

All you need to do here is the change the authorize action to use the request_token callback url and add the oauth_verifier to the callback url.

def authorize
  @token = ::RequestToken.find_by_token params[:oauth_token]
  unless @token.invalidated?
    if request.post?
      if params[:authorize] == '1'
        @token.authorize!(current_user)
        if @token.oauth10?
          @redirect_url = params[:oauth_callback] || @token.client_application.callback_url
        else
          @redirect_url = @token.oob? ? @token.client_application.callback_url : @token.callback_url
        end

        if @redirect_url
          if @token.oauth10?
            redirect_to "#{@redirect_url}?oauth_token=#{@token.token}"
          else
            redirect_to "#{@redirect_url}?oauth_token=#{@token.token}&oauth_verifier=#{@token.verifier}"
          end
        else
          render :action => "authorize_success"
        end
      elsif params[:authorize] == "0"
        @token.invalidate!
        render :action => "authorize_failure"
      end
    end
  else
    render :action => "authorize_failure"
  end
end

Alternatively if you haven’t customized your controller you can replace the full controller with this:

require 'oauth/controllers/provider_controller'
class OauthController < ApplicationController
  include OAuth::Controllers::ProviderController
end

This way the controller will automatically include bug fixes in future versions of the plugin.

The rest of the changes are in the plugin and will be automatically be included.

Note OAuth 1.0a removes support for callback url’s passed to the authorize page, clients must either define a callback url in their client application or pass one on the token request page.

If you absolutely have to support older OAuth 1.0 clients on an optional basis, we now include a switch to turn it back on.

For legacy OAUTH 1.0 support add the following constant in your environment.rb

OAUTH_10_SUPPORT = true

Note, you should only do this if you really positively require to support old OAuth1.0 clients. There is a serious security issue with this.

I recommend that you think about what your users would want to provide access to and limit oauth for those only. For example in a CRUD controller you may think about if you want to let consumer applications do the create, update or delete actions. For your application this might make sense, but for others maybe not.

If you want to give oauth access to everything a registered user can do, just replace the filter you have in your controllers with:

before_filter :login_or_oauth_required

If you want to restrict consumers to the index and show methods of your controller do the following:

before_filter :login_required, :except => [:show,:index]
before_filter :login_or_oauth_required, :only => [:show,:index]

If you have an action you only want used via oauth:

before_filter :oauth_required

You can also use this method in your controller:

oauthenticate :strategies => :token , :interactive => false

All of these places the tokens user in current_user as you would expect. It also exposes the following methods:

• current_token - for accessing the token used to authorize the current request

• current_client_application - for accessing information about which consumer is currently accessing your request

You could add application specific information to the OauthToken and ClientApplication model for such things as object level access control, billing, expiry etc. Be creative and you can create some really cool applications here.

The oauth_consumer generator creates a controller to manage the authentication flow between your application and any number of external OAuth secured applications that you wish to connect to.

To run it in Rails 3 simply run:

rails g oauth_consumer

In previous versions:

./script/generate oauth_consumer

This generates the OauthConsumerController as well as the ConsumerToken model.

By default the generator generates ERB templates. The generator can instead create HAML templates. To do this use the following options:

./script/generate oauth_consumer --haml

Rails 3 respects your application defaults, see the oauth provider generator section above for more info.

All configuration of applications is done in

config/initializers/oauth_consumers.rb

Add entries to OAUTH_CREDENTIALS for all OAuth Applications you wish to connect to. Get this information by registering your application at the particular applications developer page.

OAUTH_CREDENTIALS = {
  :twitter => {
    :key => "key",
    :secret => "secret",
    :client => :twitter_gem, # :twitter_gem or :oauth_gem (defaults to :twitter_gem)
    :expose => false, # set to true to expose client via the web
  },
  :agree2 => {
    :key => "key",
    :secret => "secret",
    :expose => false, # set to true to expose client via the web
  },
  :hour_feed => {
    :key => "",
    :secret => "",
    :options = {
      :site => "http://hourfeed.com"
    }
  },
  :nu_bux => {
    :key => "",
    :secret => "",
    :super_class => "OpenTransactToken",  # if a OAuth service follows a particular standard
                                        # with a token implementation you can set the superclass
                                        # to use
    :options => {
      :site => "http://nubux.heroku.com"
    }
  }
}

You can add any of the options that the OAuth::Consumer.new accepts to the options hash: oauth.rubyforge.org/rdoc/classes/OAuth/Consumer.html

:key, :secret are required as well as :options etc. for non custom ConsumerToken services.

For each site setup in the OAUTH_CREDENTIALS hash the plugin goes through and loads or creates a new model class that subclasses ConsumerToken.

eg. If you connect to Yahoo’s FireEagle you would add the :fire_eagle entry to OAUTH_CREDENTIALS and a new FireEagleToken model class will be created on the fly.

This allows you to add a has_one association in your user model:

has_one  :fire_eagle, :class_name => "FireEagleToken", :dependent => :destroy

And you could do:

@location = @user.fire_eagle.client.location

The client method gives you a OAuth::AccessToken which you can use to perform rest operations on the client site - see oauth.rubyforge.org/rdoc/classes/OAuth/AccessToken.html

If you are using Mongoid you want to add an embeds_many association in your user model:

embeds_many :consumer_tokens

Before creating the FireEagleToken model the plugin checks if a class already exists by that name or if we provide an api wrapper for it. This allows you to create a better token model that uses an existing ruby gem.

Currently we provide the following semi tested tokens wrappers:

• FireEagle

• Twitter

• Agree2

These can be found in lib/oauth/models/consulers/services. Contributions will be warmly accepted for your favorite OAuth service.

To connect a user to an external service link or redirect them to:

/oauth_consumers/[SERVICE_NAME]

Where SERVICE_NAME is the name you set in the OAUTH_CREDENTIALS hash. This will request the request token and redirect the user to the services authorization screen. When the user accepts the get redirected back to:

/oauth_consumers/[SERVICE_NAME]/callback

You can specify this url to the service you’re calling when you register, but it will automatically be sent along anyway.

This is designed to let your local javascript apps access remote OAuth apis. You have to specifically enable this by adding the expose flag to your oauth config file. eg:

OAUTH_CREDENTIALS = {
  :twitter => {
    :key => "key",
    :secret => "secret",
    :client => :oauth_gem, # :twitter_gem or :oauth_gem (defaults to :twitter_gem)
    :expose => true      # set to true to expose client via the web
  }

Once the user has authorized your application, you can access the client APIs via:

/oauth_consumers/[SERVICE_NAME]/client/[ENDPOINT]

For example to get the user’s Google Calendars in JSON (documented in their API as “www.google.com/calendar/feeds/default?alt=jsonc”), you would append that path as the ENDPOINT above, i.e.

/oauth_consumers/google/client/calendar/feeds/default?alt=jsonc

As another example, to get my Twitter info as XML (available at “api.twitter.com/1/users/show.xml?screen_name=pelleb”), use:

/oauth_consumers/twitter/client/1/users/show.xml?screen_name=pelleb

The database is defined in:

db/migrate/XXX_create_oauth_consumer_tokens.rb

Run them as any other normal migration in rails with:

rake db:migrate

Anyone who has a commit accepted into the official oauth-plugin git repo is awarded OAuthKarma:

picomoney.com/oauth-karma/accounts

The Mailing List for all things OAuth in Ruby is:

groups.google.com/group/oauth-ruby

The Mailing list for everything else OAuth is:

groups.google.com/group/oauth

The OAuth Ruby Gem home page is oauth.rubyforge.org

Please help documentation, patches and testing.

Copyright © 2007-2011 Pelle Braendgaard and contributors, released under the MIT license