Microsoft OAuth2 strategy for Überauth.

Quick start blog post: Authenticating users with Microsoft OAuth

1. Register an application in the Azure Portal (see Microsoft tutorial for more info).

2. Add :ueberauth_microsoft to your list of dependencies in mix.exs:

   def deps do
     [
       {:ueberauth_microsoft, "~> 0.20"}
     ]
   end

3. Add the strategy to your applications:

   def application do
     [
       applications: [:ueberauth_microsoft]
     ]
   end

4. Add Microsoft to your Überauth configuration:

   config :ueberauth, Ueberauth,
     providers: [
       microsoft: {Ueberauth.Strategy.Microsoft, []}
     ]

5. Update your provider configuration:

   config :ueberauth, Ueberauth.Strategy.Microsoft.OAuth,
     client_id: System.get_env("MICROSOFT_CLIENT_ID"),
     client_secret: System.get_env("MICROSOFT_CLIENT_SECRET")

6. Include the Überauth plug in your controller:

   defmodule MyApp.AuthController do
     use MyApp.Web, :controller
     plug Ueberauth
     ...
   end

7. Create the request and callback routes if you haven't already:

   scope "/auth", MyApp do
     pipe_through :browser
   
     get "/:provider", AuthController, :request
     get "/:provider/callback", AuthController, :callback
   end

8. Your controller needs to implement callbacks to deal with Ueberauth.Auth and Ueberauth.Failure responses.

For an example implementation see the Überauth Example application.

If you are going to use your app only internally you may need to configure it for a single tenant. To do so you only need to add tenant_id to your provider configuration like:

config :ueberauth, Ueberauth.Strategy.Microsoft.OAuth,
  tenant_id: System.get_env("MICROSOFT_TENANT_ID"),
  client_id: System.get_env("MICROSOFT_CLIENT_ID"),
  client_secret: System.get_env("MICROSOFT_CLIENT_SECRET")

Depending on the configured url you can initial the request through:

/auth/microsoft

By default the scopes used are:

• openid
• email
• offline_access
• https://graph.microsoft.com/user.read

Note: at least one service scope is required in order for a token to be returned by the Microsoft endpoint

You can configure additional scopes to be used by passing the extra_scopes option into the provider:

config :ueberauth, Ueberauth,
  providers: [
    microsoft: {
      Ueberauth.Strategy.Microsoft,
      [extra_scopes: "https://graph.microsoft.com/calendars.read"]
    }
  ]

If you would like users to have the option to choose an alternate account to authenticate with instead of defaulting to the logged in account, you may pass the prompt option in to the provider (per Microsoft documentation):

config :ueberauth, Ueberauth,
  providers: [
    microsoft: {Ueberauth.Strategy.Microsoft, [prompt: "select_account"]}
  ]

Copyright (c) 2017 Stuart Welham

Released under the MIT License, which can be found in the repository in LICENSE.