OmniAuth Windows Azure Active Directory Strategy

This gem provides a simple way to authenticate to Windows Azure Active Directory (WAAD) over OAuth2 using OmniAuth.

One of the unique challenges of WAAD OAuth is that WAAD is multi tenant. Any given tenant can have multiple active directories. The CLIENT-ID, REPLY-URL and keys will be unique to the tenant/AD/application combination. This gem simply provides hooks for determining those unique values for each call.

Installation

Add this line to your application's Gemfile:

gem 'omniauth-azure-oauth2'

Usage

First, you will need to add your site as an application in WAAD.: Adding, Updating, and Removing an Application

Summary: Select your Active Directory in https://manage.windowsazure.com/ of type 'Web Application'. Name, sign-on url, logo are not important. You will need the CLIENT-ID from the application configuration and you will need to generate an expiring key (aka 'client secret'). REPLY URL is the oauth redirect uri which will be the omniauth callback path https://example.com/users/auth/azure_oauth2/callback. The APP ID UI just needs to be unique to that tenant and identify your site and isn't needed to configure the gem. Permissions need Delegated Permissions to at least have "Enable sign-on and read user's profiles".

Note: Seems like the terminology is still fluid, so follow the MS guidance (buwahaha) to set this up.

The TenantInfo information can be a hash or class. It must provide client_id and client_secret. Optionally a domain_hint and tenant_id. For a simple single-tenant app, this could be:

use OmniAuth::Builder do
  provider :azure_oauth2,
    {
      client_id: ENV['AZURE_CLIENT_ID'],
      client_secret: ENV['AZURE_CLIENT_SECRET'],
      tenant_id: ENV['AZURE_TENANT_ID']
    }
end

Or the alternative format for use with devise:

config.omniauth :azure_oauth2, client_id: ENV['AZURE_CLIENT_ID'],
      client_secret: ENV['AZURE_CLIENT_SECRET'], tenant_id: ENV['AZURE_TENANT_ID']

For multi-tenant apps where you don't know the tenant_id in advance, simply leave out the tenant_id to use the common endpoint.

use OmniAuth::Builder do
  provider :azure_oauth2,
    {
      client_id: ENV['AZURE_CLIENT_ID'],
      client_secret: ENV['AZURE_CLIENT_SECRET']
    }
end

For dynamic tenant assignment, pass a class that supports those same attributes and accepts the strategy as a parameter

class YouTenantProvider
  def initialize(strategy)
    @strategy = strategy
  end

  def client_id
    tenant.azure_client_id
  end

  def client_secret
    tenant.azure_client_secret
  end

  def tenant_id
    tenant.azure_tanant_id
  end

  def domain_hint
    tenant.azure_domain_hint
  end

  private

  def tenant
    # whatever strategy you want to figure out the right tenant from params/session
    @tenant ||= Customer.find(@strategy.session[:customer_id])
  end
end

use OmniAuth::Builder do
  provider :azure_oauth2, YourTenantProvider
end

Auth Hash Schema

The following information is provided back to you for this provider:

{
  uid: '12345',
  info: {
    name: 'some one',
    first_name: 'some',
    last_name: 'one',
    email: '[email protected]'
  },
  credentials: {
    token: 'thetoken',
    refresh_token: 'refresh'
  },
  extra: { raw_info: raw_api_response }
}

notes

When you make a request to WAAD you must specify a resource. The gem currently assumes this is the AD identified as '00000002-0000-0000-c000-000000000000'. This can be passed in as part of the config. It currently isn't designed to be dynamic.

use OmniAuth::Builder do
  provider :azure_oauth2, TenantInfo, resource: 'myresource'
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Make your changes, add tests, run tests (rake)
4. Commit your changes and tests (git commit -am 'Added some feature')
5. Push to the branch (git push origin my-new-feature)
6. Create new Pull Request

Misc

Run tests bundle exec rake
Push to rubygems bundle exec rake release.