AshAuthentication provides a turn-key authentication solution for folks using Ash.

Usage

This package assumes that you have Ash installed and configured. See the Ash documentation for details.

Once installed you can easily add support for authentication by configuring the AshAuthentication extension on your resource:

defmodule MyApp.Accounts.User do
  use Ash.Resource,
    extensions: [AshAuthentication]

  attributes do
    uuid_primary_key :id
    attribute :email, :ci_string, allow_nil?: false
    attribute :hashed_password, :string, allow_nil?: false, sensitive?: true
  end

  authentication do
    api MyApp.Accounts

    strategies do
      password :password do
        identity_field :email
        hashed_password_field :hashed_password
      end
    end
  end

  identities do
    identity :unique_email, [:email]
  end
end

If you plan on providing authentication via the web, then you will need to define a plug using AshAuthentication.Plug which builds a Plug.Router that routes incoming authentication requests to the correct provider and provides callbacks for you to manipulate the conn after success or failure.

If you're using AshAuthentication with Phoenix, then check out ash_authentication_phoenix which provides route helpers, a controller abstraction and LiveView components for easy set up.

Authentication Strategies

Currently supported strategies:

1. AshAuthentication.Strategy.Password
   • authenticate users against your local database using a unique identity (such as username or email address) and a password.
2. AshAuthentication.Strategy.OAuth2
   • authenticate using local or remote OAuth 2.0 compatible services.

Add-ons

Add-ons are like strategies, except that they don't actually provide authentication - they just provide features adjacent to authentication. Current add-ons:

1. AshAuthentication.AddOn.Confirmation
   • allows you to force the user to confirm changes using a confirmation token (eg. sending a confirmation email when a new user registers).

Supervisor

Some add-ons or strategies may require processes to be started which manage their state over the lifetime of the application (eg periodically deleting expired token revocations). Because of this you should add {AshAuthentication.Supervisor, otp_app: :my_app} to your application's supervision tree. See the Elixir docs for more information.

DSL Documentation

Index

• authentication
  • tokens
  • strategies
  • add_ons

Docs

authentication

Configure authentication for this resource

• tokens
• strategies
• add_ons

• :subject_name (atom/0) - The subject name is used anywhere that a short version of your resource name is needed, eg:

  • generating token claims,
  • generating routes,
  • form parameter nesting.
    This needs to be unique system-wide and if not set will be inferred from the resource name (ie MyApp.Accounts.User will have a subject name of user).

• :api (atom/0) - Required. The name of the Ash API to use to access this resource when doing anything authenticaiton related.

• :get_by_subject_action_name (atom/0) - The name of the read action used to retrieve records.
  Used internally by AshAuthentication.subject_to_user/2. If the action doesn't exist, one will be generated for you. The default value is :get_by_subject.

• :select_for_senders (list of atom/0) - A list of fields that we will ensure are selected whenever a sender will be invoked. This is useful if using something like ash_graphql which by default only selects what fields appear in the query, and if you are exposing these actions that way. Defaults to [:email] if there is an :email attribute on the resource, and [] otherwise.

tokens

Configure JWT settings for this resource

• :enabled? (boolean/0) - Should JWTs be generated by this resource? The default value is false.

• :store_all_tokens? (boolean/0) - Store all tokens in the token_resource?
  Some applications need to keep track of all tokens issued to any user. This is optional behaviour with ash_authentication in order to preserve as much performance as possible. The default value is false.

• :require_token_presence_for_authentication? (boolean/0) - Require a locally-stored token for authentication?
  This inverts the token validation behaviour from requiring that tokens are not revoked to requiring any token presented by a client to be present in the token resource to be considered valid.
  Requires store_all_tokens? to be true. The default value is false.

• :signing_algorithm (String.t/0) - The algorithm to use for token signing.
  Available signing algorithms are; EdDSA, Ed448ph, Ed448, Ed25519ph, Ed25519, PS512, PS384, PS256, ES512, ES384, ES256, RS512, RS384, RS256, HS512, HS384 and HS256. The default value is "HS256".

• :token_lifetime (pos_integer/0) - How long a token should be valid, in hours.
  Since refresh tokens are not yet supported, you should probably set this to a reasonably long time to ensure a good user experience.
  Defaults to 14 days. The default value is 336.

• :token_resource - Required. The resource used to store token information.
  If token generation is enabled for this resource, we need a place to store information about tokens, such as revocations and in-flight confirmations.

• :signing_secret - The secret used to sign tokens.
  Takes either a module which implements the AshAuthentication.Secret behaviour, a 2 arity anonymous function or a string.
  See the module documentation for AshAuthentication.Secret for more information.

strategies

Configure authentication strategies on this resource

add_ons

Additional add-ons related to, but not providing authentication