Curator

An Authentication Framework for Phoenix.

Curator is meant to mimic Devise, as such it provides several modules to accomplish authentication and various aspects of user lifecycle mangement. It's build with a modular architecture that differs from existing Elixir Authentication solutions. Each curator module can be combined to handle various authentication scenarios, passing coordination through a curator module](#curator-module). Under the hood, this uses Guardian for session management.

For an example, see the PhoenixCurator Application

Curator Modules

Ueberauth: Ueberauth Integration.
Timeoutable: Session Timeout (after configurable inactivity).

(TODO)

Registerable: A Generator to support user registration.
Database Authenticatable: Compare a password to a hashed password to support password based sign-in. Also provide a generator for creating a session page.
Confirmable: Account email verification.
Recoverable: Reset the User Password.
Lockable: Lock Account after configurbale count of invalid sign-ins.
Approvable: Require an approval step before user sign-in.

Installation

Add curator to your list of dependencies in mix.exs:

 def deps do
   [{:curator, "~> 0.2.2"}]
 end

Run the install command
```
 mix curator.install
```
This will generate:
1. A User context, migration, and schema (in the Ecto application if an umbrella)
  - A user migration (priv/repo/migrations/<timestamp>_create_users.exs)
  - A user schema (<my_app>/lib/<my_app>/auth/user.ex)
  - A user context (<my_app>/lib/<my_app>/auth/auth.ex)
2. An empty Curator module (<my_app_web>/lib/<my_app_web>/auth/curator.ex)
3. A Guardian Configuration
  - A Guardian module (<my_app_web>/lib/<my_app_web>/auth/guardian.ex)
  - An error handler (<my_app_web>/lib/<my_app_web>/controllers/auth/error_handler.ex)
4. A view helper (<my_app_web>/lib/<my_app_web>/views/auth/curator_helper.ex)
5. A Session Controller
  - controller (<my_app_web>/lib/<my_app_web>/controllers/auth/session_controller.ex)
  - view helper (<my_app_web>/lib/<my_app_web>/views/auth/curator_helper.ex)
  - new template (<my_app_web>/lib/<my_app_web>/templates/auth/session/new.html.eex). Note: this is just a placeholder that you'll want to update when you decide on a sign-in strategy.

The generators aren't perfect (TODO), so finish the installation

Update your router (<my_app_web>/lib/<my_app_web>/router.ex)

 require Curator.Router
 
 pipeline :browser do
   ...
   plug <MyWebApp>.Auth.Curator.UnauthenticatedPipeline
 end
 
 pipeline :authenticated_browser do
   ... (copy the code from browser)
   plug <MyWebApp>.Auth.Curator.AuthenticatedPipeline
 end
 
 scope "/", <MyWebApp> do
   pipe_through :browser
     
   ...
   Insert your unprotected routes here
   ...
 
   Curator.Router.mount_unauthenticated_routes(<MyWebApp>.Auth.Curator)
 end
 
 scope "/", <MyWebApp> do
   pipe_through :authenticated_browser
   
   ...
   Insert your urotected routes here
   ...
 
   Curator.Router.mount_authenticated_routes(<MyWebApp>.Auth.Curator)
 end

Add the view_helper to your web module (<my_app_web>/lib/<my_app_web>.ex)
```
 def view do
   quote do
     ...
 
     import <MyAppWeb>.Auth.CuratorHelper
   end
 end
```
This allows you to call current_user(@conn) in your templates

Configure Guardian in config.exs

 config :<my_app_web>, <MyAppWeb>.Auth.Guardian,
   issuer: "<my_app_web>",
   secret_key: "Secret key. You can use `mix guardian.gen.secret` to get one"

Add to your Auth Context (<my_app>/lib/<my_app>/auth/auth.ex)
```
   def get_user(id), do: Repo.get(User, id)
```

Add a signout link to your layout

 <%= if current_user(@conn) do %>
   <%= link "Sign Out", to: session_path(@conn, :delete), method: :delete %>
 <% end %>

Testing

Update conn_case.ex:

 setup tags do
   :ok = Ecto.Adapters.SQL.Sandbox.checkout(<MyApp>.Repo)
   unless tags[:async] do
     Ecto.Adapters.SQL.Sandbox.mode(<MyApp>.Repo, {:shared, self()})
   end
 
   # Create w/ ExMachina (or your preferred method)
   # Note: As you add additional modules, make sure this user is valid for them too.
   auth_user = <MyApp>.Factory.insert(:auth_user)
 
   {:ok, token, claims} = <MyAppWeb>.Auth.Guardian.encode_and_sign(auth_user)
 
   conn = Phoenix.ConnTest.build_conn()
 
   auth_conn = conn
   |> Plug.Test.init_test_session(%{
     guardian_default_token: token,
     guardian_default_timeoutable: Curator.Time.timestamp(),
   })
 
   {:ok, unauth_conn: conn, auth_user: auth_user, conn: auth_conn}
 end

Note: This uses conn as an authenticated connection, so existing tests won't need to be updated.

To test, I created some special routes:

 scope "/", <MyAppWeb> do
   pipe_through :browser
 
   if Mix.env == :test do
     get "/insecure", PageController, :insecure
   end
 
   Curator.Router.mount_unauthenticated_routes(<MyAppWeb>.Auth.Curator)
 end
 
 scope "/", <MyAppWeb> do
   pipe_through :authenticated_browser
 
   if Mix.env == :test do
     get "/secure", PageController, :secure
   end
 
   Curator.Router.mount_authenticated_routes(<MyAppWeb>.Auth.Curator)
 end

Update the page_controller.ex:

 defmodule <MyAppWeb>.PageController do
   use <MyAppWeb>, :controller
 
   def secure(conn, _params) do
     text conn, "!!!SECURE!!!"
   end
 
   def insecure(conn, _params) do
     text conn, "INSECURE"
   end
 end

And wrote tests in page_controller_test.exs:

 defmodule <MyAppWeb>.PageControllerTest do
   use <MyAppWeb>.ConnCase
 
   test "GET /secure (Unauthenticated)", %{unauth_conn: conn} do
     conn = get conn, "/secure"
     assert redirected_to(conn) == session_path(conn, :new)
     assert get_flash(conn, :error) == "Please Sign In"
   end
     
   test "GET /secure (Authenticated)", %{conn: conn} do
     conn = get conn, "/secure"
     assert text_response(conn, 200) == "!!!SECURE!!!"
   end
     
   test "GET /secure (Authenticated - User Delete)", %{conn: conn, auth_user: user} do
     <MyApp>.Auth.delete_user(user)
     conn = get conn, "/secure"
     assert redirected_to(conn) == session_path(conn, :new)
     assert get_flash(conn, :error) == "Please Sign In"
   end
     
   test "GET /insecure (Unauthenticated)", %{unauth_conn: conn} do
     conn = get conn, "/insecure"
     assert text_response(conn, 200) == "INSECURE"
   end
     
   test "GET /insecure (Authenticated)", %{conn: conn} do
     conn = get conn, "/insecure"
     assert text_response(conn, 200) == "INSECURE"
   end
     
   test "GET /insecure (Authenticated - User Delete)", %{conn: conn, auth_user: user} do
     <MyApp>.Auth.delete_user(user)
     conn = get conn, "/insecure"
     assert redirected_to(conn) == session_path(conn, :new)
     assert get_flash(conn, :error) == "Please Sign In"
   end
 end

These examples can be extended as additional modules are integrated (ex. using Confirmable with a user that hasn't been confirmed).

Curate.
Your authentication library is looking a bit spartan... Time to add to you collection.
Currently only an oauth workflow is supported, so start with Ueberauth

Module Documentation

Ueberauth

Description

Ueberauth Integration

Installation

Run the install command
```
 mix curator.ueberauth.install
```

Add to the curator modules (<my_app_web>/lib/<my_app_web>/auth/curator.ex)

 use Curator, otp_app: :my_app_web,
   modules: [
     <MyAppWeb>.Auth.Ueberauth,
   ]

Install Ueberauth and the desired strategies. For example, to add google oauth:

Update mix.exs

 defp deps do
   [
     {:ueberauth, "~> 0.4"},
     {:ueberauth_google, "~> 0.7"},
   ]
 end

NOTE: If you're using an umbrella app you'll also need to add ueberauth to your ecto applications mix.exs.

Update config.exs

 config :ueberauth, Ueberauth,
   providers: [
     google: {Ueberauth.Strategy.Google, []}
   ]
 
 config :ueberauth, Ueberauth.Strategy.Google.OAuth,
   client_id: System.get_env("GOOGLE_CLIENT_ID"),
   client_secret: System.get_env("GOOGLE_CLIENT_SECRET")

Put some links to the providers (<my_app_web>/lib/<my_app_web>/templates/auth/session/new.html.eex)

 <%= link "Google", to: ueberauth_path(@conn, :request, "google"), class: "btn btn-default" %>

Timeoutable

Description

Session Timeout (after configurable inactivity)

Installation

Run the install command
```
 mix curator.timeoutable.install
```

Add to the curator modules (<my_app_web>/lib/<my_app_web>/auth/curator.ex)

 use Curator, otp_app: :<my_app_web>,
   modules: [
    <MyAppWeb>.Auth.Timeoutable,
   ]

Add to the curator plugs

 defmodule <MyAppWeb>.Auth.Curator.UnauthenticatedPipeline do
   ...
   plug Curator.Timeoutable.Plug, timeoutable_module: <MyAppWeb>.Auth.Timeoutable
 end
 
 defmodule <MyAppWeb>.Auth.Curator.AuthenticatedPipeline do
   ...
   plug Curator.Timeoutable.Plug, timeoutable_module: <MyAppWeb>.Auth.Timeoutable
 end

(optional) Configure Timeoutable (<my_app_web>/lib/<my_app_web>/auth/timeoutable.ex)
```
 use Curator.Timeoutable, otp_app: :<my_app_web>,
   timeout_in: 1800
```

Update tests (<my_app_web>/test/support/conn_case.ex)

 auth_conn = conn
 |> Plug.Test.init_test_session(%{
   guardian_default_token: token,
   guardian_default_timeoutable: Curator.Time.timestamp(),
 })

This session key usually is set as part of the after_sign_in extension.

(optional) Update the ErrorHandler (<my_app_web>/lib/<my_app_web>/controllers/auth/error_handler.ex)

 defp translate_error({:timeoutable, :timeout}), do: "You have been signed out due to inactivity"

Registerable (TODO)

Database Authenticatable (TODO)

Confirmable (TODO)

Recoverable (TODO)

Lockable (TODO)

Approvable (TODO)

Extending Curator (TODO)

Debt

Thanks go out to the Phoenix Team, the original rails gem Devise, Guardian, and the other elixir authentication solutions:

Any decent ideas I credit to them, I was just acting as the curator.