Use Google, Github, Twitter, Facebook, or add your custom strategy for authorization to your Pow enabled Phoenix app.
- Collects required user id field from the user if the user id is missing from the provider
- Multiple providers can be used for accounts
- When removing authentication, user is validated for password or alternative provider
- You can add your custom strategy with ease
- Includes the following base strategies:
- Includes the following provider strategies:
Add PowAssent to your list of dependencies in mix.exs:
def deps do
[
# ...
{:pow_assent, "~> 0.3.1"},
# Optional, but recommended for SSL validation with :httpc adapter
{:certifi, "~> 2.4"},
{:ssl_verify_fun, "~> 1.1"},
# ...
]
endRun mix deps.get to install it.
It's required to set up Pow first. You can run these quick setup instructions if Pow hasn't already been set up.
If your user schema uses binary id, then run the PowAssent mix task(s) with the --binary-id flag.
Install the necessary files:
mix pow_assent.installThis will add the following files to your app:
LIB_PATH/user_identities/user_identity.ex
PRIV_PATH/repo/migrations/TIMESTAMP_create_user_identities.exUpdate LIB_PATH/users/user.ex:
defmodule MyApp.Users.User do
use Ecto.Schema
use Pow.Ecto.Schema
use PowAssent.Ecto.Schema
schema "users" do
pow_user_fields()
# ...
timestamps()
end
# ..
endSet up router.ex:
defmodule MyAppWeb.Router do
use MyAppWeb, :router
use Pow.Phoenix.Router
use PowAssent.Phoenix.Router
# ...
scope "/" do
pipe_through [:browser]
pow_routes()
pow_assent_routes()
end
# ...
endThe following routes will now be available in your app:
pow_assent_authorization_path GET /auth/:provider/new PowAssent.Phoenix.AuthorizationController :new
pow_assent_authorization_path DELETE /auth/:provider PowAssent.Phoenix.AuthorizationController :delete
pow_assent_authorization_path GET /auth/:provider/callback PowAssent.Phoenix.AuthorizationController :callback
pow_assent_registration_path GET /auth/:provider/add-user-id PowAssent.Phoenix.RegistrationController :add_user_id
pow_assent_registration_path POST /auth/:provider/create PowAssent.Phoenix.RegistrationController :createRemember to run the new migrations with:
mix ecto.setupIf you're modifying the Pow templates, then you have to generate the PowAssent template too:
mix pow_assent.phoenix.gen.templatesOtherwise, Pow will raise an error about missing template when the user id field template is shown.
You can use PowAssent.Phoenix.ViewHelpers.provider_links/1 to add provider links to your template files:
<%= for link <- PowAssent.Phoenix.ViewHelpers.provider_links(@conn),
do: content_tag(:span, link) %>This can be used in the WEB_PATH/templates/pow/session/new.html.eex, WEB_PATH/templates/pow/registration/new.html.eex and WEB_PATH/templates/pow/registration/edit.html.eex templates.
By default "Sign in with PROVIDER" link is shown. A "Remove PROVIDER authentication" link will be shown instead if the user is signed in and the user already have authorized with the provider.
You can also call PowAssent.Phoenix.ViewHelpers.authorization_link/2 and PowAssent.Phoenix.ViewHelpers.deauthorization_link/2 to generate a link for a single provider.
PowAssent has multiple strategies that you can use. Let's go through how to set up the Github strategy.
First, register a new app on Github and add http://localhost:4000/auth/github/callback as the callback URL. Then add the following to config/config.exs and add the client id and client secret (for production keys you would want to set this in config/prod.secret.exs):
config :my_app, :pow_assent,
providers: [
github: [
client_id: "REPLACE_WITH_CLIENT_ID",
client_secret: "REPLACE_WITH_CLIENT_SECRET",
strategy: PowAssent.Strategy.Github
]
]Now start (or restart) your Phoenix app, and visit http://localhost:4000/auth/github/new.
You can add your own custom strategy.
Here's an example of an OAuth 2.0 implementation using PowAssent.Strategy.OAuth2.Base:
defmodule TestProvider do
use PowAssent.Strategy.OAuth2.Base
def default_config(_config) do
[
site: "http://localhost:4000/",
authorize_url: "http://localhost:4000/oauth/authorize",
token_url: "http://localhost:4000/oauth/access_token",
user_url: "/user",
authorization_params: [scope: "email profile"]
]
end
def normalize(_config, user) do
%{
"uid" => user["sub"],
"name" => user["name"],
"email" => user["email"]
}
end
endYou can also use PowAssent.Strategy:
defmodule TestProvider do
@behaviour PowAssent.Strategy
@spec authorize_url(Keyword.t()) :: {:ok, %{url: binary()}} | {:error, term()}
def authorize_url(config) do
# Generate authorization url
end
@spec callback(Keyword.t(), map()) :: {:ok, %{user: map()}} | {:error, term()}
def callback(config, params) do
# Handle callback response
end
endThe template can be generated and modified to use your Gettext module with mix pow_assent.phoenix.gen.templates
For flash messages, you should add them to your Pow.Phoenix.Messages module the same way as all Pow extension flash messages:
defmodule MyAppWeb.Pow.Messages do
use Pow.Phoenix.Messages
use Pow.Extension.Phoenix.Messages,
extensions: [PowAssent]
import MyAppWeb.Gettext
# ...
def pow_assent_signed_in(conn) do
provider = Phoenix.Naming.humanize(conn.params["provider"])
gettext("You've been signed in with %{provider}.", provider)
end
endAdd messages_backend: MyAppWeb.Pow.Messages to your configuration. You can find all messages in PowAssent.Phoenix.Messages.
To populate fields in your user struct that are fetched from the provider, you only need to cast them in user_identity_changeset/4 method like so:
defmodule MyApp.Users.User do
use Ecto.Schema
use Pow.Ecto.Schema
use PowAssent.Ecto.Schema
schema "users" do
field :custom_field, :string
pow_user_fields()
timestamps()
end
def user_identity_changeset(user_or_changeset, user_identity, attrs, user_id_attrs) do
user_or_changeset
|> Ecto.Changeset.cast(attrs, [:custom_field])
|> pow_assent_user_identity_changeset(user_identity, attrs, user_id_attrs)
end
endThe fields available can be found in the normalize/2 method of the strategy.
You can disable registration by only using pow_assent_authorization_routes/0 in router.ex:
defmodule MyAppWeb.Router do
use MyAppWeb, :router
use Pow.Phoenix.Router
use PowAssent.Phoenix.Router
# ...
scope "/" do
pipe_through [:browser]
pow_routes()
pow_assent_authorization_routes()
end
# ...
endPowAssent will pick it up in the authorization flow, and prevent creating a user if the registration path is missing.
By default Erlangs built-in :httpc is used for requests. SSL verification is automatically enabled when :certifi and :ssl_verify_fun packages are available. :httpc only supports HTTP/1.1.
If you would like HTTP/2 support, you should consider adding Mint to your project.
Update mix.exs:
def deps do
[
# ...
{:mint, "~> 0.1.0"},
{:castore, "~> 0.1.0"}, # Required for SSL validation
# ...
]
endUpdate the PowAssent configuration with:
config :my_app, :pow_assent,
http_adapter: PowAssent.HTTPAdapter.MintPowAssent works by the assumption that you name your schema modules in the form of [App].[Context].[Schema]. If you have a different module naming, all you have to do is to add the has_many association to your user module like so:
defmodule MyApp.Lib.User do
use Ecto.Schema
use Pow.Ecto.Schema
use PowAssent.Ecto.Schema
schema "users" do
has_many :user_identities,
MyApp.Lib.UserIdentity,
on_delete: :delete_all,
foreign_key: :user_id
pow_user_fields()
# ...
timestamps()
end
# ..
endOtherwise you'll get an error that reads:
warning: invalid association `user_identities` in schema MyApp.Lib.User: associated schema MyApp.UserIdentities.UserIdentity does not exist
The e-mail fetched from the provider is assumed already confirmed, and the user will have :email_confirmed_at set when inserted. If a user enters an e-mail then the user will have to confirm their e-mail before they can sign in.
PowAssent works out of the box with PowInvitation. If a user identity is created, the an invited user will have the :invitation_accepted_at set.
Provider links will have an invitation_token query param if an invited user exists in the connection. This will be used in the authorization callback flow to load the invited user.
All sessions created through PowAssent provider authentication are temporary. However, it's a good idea to do some housekeeping in your app and make sure that you have the level of security as warranted by the scope of your app. That may include requiring users to re-authenticate before viewing or editing their user details.
(The MIT License)
Copyright (c) 2018-2019 Dan Schultzer & the Contributors
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.