letmein

letmein is a minimalistic authentication plugin for Rails 3 applications. It doesn't have anything other than the UserSession (or WhateverSession) object that you can use to authenticate logins.

Setup

Plug the thing below into Gemfile and you know what to do after.

gem 'letmein'

If you want to authenticate User with database fields email, password_hash and password_salt you don't need to do anything. If you're authenticating something else, you want something like this in your initializers:

LetMeIn.initialize(
  :model      => 'Account',
  :identifier => 'username',
  :password   => 'password_crypt',
  :salt       => 'salty_salt
)

When creating/updating a record you have access to password accessor.

>> user = User.new(:email => 'example@example.com', :password => 'letmein')
>> user.save!
=> true
>> user.password_hash 
=> $2a$10$0MeSaaE3I7.0FQ5ZDcKPJeD1.FzqkcOZfEKNZ/DNN.w8xOwuFdBCm
>> user.password_salt
=> $2a$10$0MeSaaE3I7.0FQ5ZDcKPJe

Authentication

You authenticate using UserSession object. Example:

>> session = UserSession.new(:email => 'example@example.com', :password => 'letmein')
>> session.save
=> true
>> session.user
=> #<User id: 1, email: "example@example.com" ... >

When credentials are invalid:

>> session = UserSession.new(:email => 'example@example.com', :password => 'bad_password')
>> session.save
=> false
>> session.user
=> nil

Usage

There are no built-in routes/controllers/views/helpers or anything. I'm confident you can do those yourself, because you're awesome. But here's an example how you can implement the controller handling the login:

class SessionsController < ApplicationController
  def create
    @session = UserSession.new(params[:user_session])
    @session.save!
    session[:user_id] = @session.user.id
    flash[:notice] = "Welcome back #{@session.user.name}!"
    redirect_to '/'

  rescue LetMeIn::Error
    flash.now[:error] = 'Invalid Credentials'
    render :action => :new
  end
end

Upon successful login you have access to session[:user_id]. The rest is up to you.

Authenticating Multiple Models

Yes, you can do that too. Let's assume you also want to authenticate admins that don't have email addresses, but have usernames.

LetMeIn.initialize(
  :model      => ['User', 'Admin'],
  :identifier => ['email', 'username']
)

Bam! You're done. Now you have an AdminSession object that will use username and password to authenticate.

Copyright

(c) 2011 Oleg Khabarov, released under the MIT license