auth

A framework-agnostic strategy-based approach to authentication.

Features:

• Common strategies to rapidly implement common authentication workflows (WIP)
• Easy-to-provide conversion between strategy users (such as a Firebase User) and your app user model
• Default session storage and (ability for) retrieval
• Create custom strategies with no required knowledge of app use-case

Installation

Add this to your application's shard.yml:

dependencies:
  auth:
    github: randomstate/auth

Usage

require "auth"
require "auth_firebase_jwt" # or your favourite strategy implementation for this shard

## Define required context for your app

# 1) Enable type-safe support for your User class. This generates the appropriate strategy base classes to support your model. It *MUST* be called.
# 2) List which strategies are supported. This sets up the auth manager class so that it can dynamically add and remove strategies by name. It *MUST* be called.
Auth.define_user_class MyUserClass
Auth.can_use Auth::Strategies::Firebase::JWT # , MyOtherStrategy, YetAnotherStrategyClass

## Create an Auth::Manager instance
manager = Auth::Manager.new

## Register your strategies with the manager
firebase_jwt = Auth::Strategies::Firebase::JWT.new "project-1328"
manager.use :jwt, firebase_jwt

# Define how the strategy should convert the Firebase User to your own version
firebase_jwt.when_converting do | firebase_user |
  user = MyUser.new # most likely you will fetch/upsert it from/in the database 

  user.email = firebase_user.email #etc
  user # return your user instance
end


## Elsewhere in your app (most likely in a middleware)
user = manager.authenticate(:jwt, context) # context : HTTP::Server::Context

if user.nil?
  # not authenticated
else 
  # authenticated `MyUser` object
end

Quick Start with Amber Framework

Follow the instructions (detailed above):

• Call Auth.define_user_class
• Call Auth.can_use with your strategies as parameters
• Create an Auth::Manager instance
• Register your strategies with the manager
• Define how your strategy should convert to your custom user model

Then add this to your config/routes.cr file in the pipes section for the relevant route:

Auth::Pipe::Authenticate.new(manager, :strategy_name) # strategy_name is the symbol referencing your strategy, as defined when you registered your strategies with the manager

This pipe will now guard any routes in the pipeline. It will raise an Auth::Pipe::Unauthorized exception if the user failed to authenticate. By default this will return a response with "Unauthorized." and a status code of 401.

Inside your controller, you can now access the authenticated user like so:

class MyController < ApplicationController

  def index
    authenticated_user = @context.user # typeof(authenticated_user) == (MyUser | Nil)
  end

end

Development

Implementing Custom Strategies

[[ TODO ]]

Contributing

1. Fork it ( https://github.com/randomstate/auth/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• cimrie Connor Imrie - creator, maintainer