[](https://github.com/mikker/passwordless/actions/workflows/ci.yml) [](https://rubygems.org/gems/passwordless) [](https://codecov.io/gh/mikker/passwordless) Add authentication to your Rails app without all the icky-ness of passwords. _Magic link_ authentication, if you will. We call it _passwordless_. - [Installation](#installation) - [Upgrading](#upgrading) - [Usage](#usage) - [Getting the current user, restricting access, the usual](#getting-the-current-user-restricting-access-the-usual) - [Providing your own templates](#providing-your-own-templates) - [Registering new users](#registering-new-users) - [URLs and links](#urls-and-links) - [Route constraints](#route-constraints) - [Configuration](#configuration) - [Delivery method](#delivery-method) - [Token generation](#token-generation) - [Timeout and Expiry](#timeout-and-expiry) - [Redirection after sign-in](#redirection-after-sign-in) - [Looking up the user](#looking-up-the-user) - [Test helpers](#test-helpers) - [Security considerations](#security-considerations) - [Alternatives](#alternatives) - [License](#license) ## Installation Add to your bundle and copy over the migrations: ```sh $ bundle add passwordless $ bin/rails passwordless_engine:install:migrations ``` ### Upgrading See [Upgrading to Passwordless 1.0](docs/upgrading_to_1_0.md) for more details. ## Usage Passwordless creates a single model called `Passwordless::Session`, so it doesn't come with its own user model. Instead, it expects you to provide one, with an email field in place. If you don't yet have a user model, check out the wiki on [creating the user model](https://github.com/mikker/passwordless/wiki/Creating-the-user-model). Enable Passwordless on your user model by pointing it to the email field: ```ruby class User < ApplicationRecord # your other code.. passwordless_with :email # <-- here! this needs to be a column in `users` table # more of your code.. end ``` Then mount the engine in your routes: ```ruby Rails.application.routes.draw do passwordless_for :users # other routes end ``` ### Getting the current user, restricting access, the usual Passwordless doesn't give you `current_user` automatically. Here's how you could add it: ```ruby class ApplicationController < ActionController::Base include Passwordless::ControllerHelpers # <-- This! # ... helper_method :current_user private def current_user @current_user ||= authenticate_by_session(User) end def require_user! return if current_user save_passwordless_redirect_location!(User) # <-- optional, see below redirect_to root_path, alert: "You are not worthy!" end end ``` Et voilà: ```ruby class VerySecretThingsController < ApplicationController before_action :require_user! def index @things = current_user.very_secret_things end end ``` ### Providing your own templates To make Passwordless look like your app, override the bundled views by adding your own. You can manually copy the specific views that you need or copy them to your application with `rails generate passwordless:views`. Passwordless has 2 action views and 1 mailer view: ```sh # the form where the user inputs their email address app/views/passwordless/sessions/new.html.erb # the form where the user inputs their just received token app/views/passwordless/sessions/show.html.erb # the email with the token and magic link app/views/passwordless/mailer/sign_in.text.erb ``` See [the bundled views](https://github.com/mikker/passwordless/tree/master/app/views/passwordless). ### Registering new users Because your `User` record is like any other record, you create one like you normally would. Passwordless provides a helper method to sign in the created user after it is saved – like so: ```ruby class UsersController < ApplicationController include Passwordless::ControllerHelpers # <-- This! # (unless you already have it in your ApplicationController) def create @user = User.new(user_params) if @user.save sign_in(create_passwordless_session(@user)) # <-- This! redirect_to(@user, flash: { notice: 'Welcome!' }) else render(:new) end end # ... end ``` ### URLs and links By default, Passwordless uses the resource name given to `passwordless_for` to generate its routes and helpers. ```ruby passwordless_for :users # <%= users_sign_in_path %> # => /users/sign_in passwordless_for :users, at: '/', as: :auth # <%= auth_sign_in_path %> # => /sign_in ``` Also be sure to [specify ActionMailer's `default_url_options.host`](http://guides.rubyonrails.org/action_mailer_basics.html#generating-urls-in-action-mailer-views) and tell the routes as well: ```ruby # config/application.rb for example: config.action_mailer.default_url_options = {host: "www.example.com"} routes.default_url_options[:host] ||= "www.example.com" ``` ### Route constraints With [constraints](https://guides.rubyonrails.org/routing.html#request-based-constraints) you can restrict access to certain routes. Passwordless provides `Passwordless::Constraint` and it's negative counterpart `Passwordless::NotConstraint` for this purpose. To limit a route to only authenticated `User`s: ```ruby constraints Passwordless::Constraint.new(User) do # ... end ``` The constraint takes a second `if:` argument, that expects a block and is passed the `authenticatable` record, (ie. `User`): ```ruby constraints Passwordless::Constraint.new(User, if: -> (user) { user.email.include?("john") }) do # ... end ``` The negated version has the same API but with the opposite result, ie. ensuring authenticated user **don't** have access: ```ruby constraints Passwordless::NotConstraint.new(User) do get("/no-users-allowed", to: "secrets#index") end ``` ## Configuration To customize Passwordless, create a file `config/initializers/passwordless.rb`. The default values are shown below. It's recommended to only include the ones that you specifically want to modify. ```ruby Passwordless.configure do |config| config.default_from_address = "CHANGE_ME@example.com" config.parent_controller = "ApplicationController" config.parent_mailer = "ActionMailer::Base" config.restrict_token_reuse = true # Can a token/link be used multiple times? config.token_generator = Passwordless::ShortTokenGenerator.new # Used to generate magic link tokens. config.expires_at = lambda { 1.year.from_now } # How long until a signed in session expires. config.timeout_at = lambda { 10.minutes.from_now } # How long until a token/magic link times out. config.redirect_back_after_sign_in = true # When enabled the user will be redirected to their previous page, or a page specified by the `destination_path` query parameter, if available. config.redirect_to_response_options = {} # Additional options for redirects. config.success_redirect_path = '/' # After a user successfully signs in config.failure_redirect_path = '/' # After a sign in fails config.sign_out_redirect_path = '/' # After a user signs out config.paranoid = false # Display email sent notice even when the resource is not found. end ``` ### Delivery method By default, Passwordless sends emails. See [Providing your own templates](#providing-your-own-templates). If you need to customize this further, you can do so in the `after_session_save` callback. In `config/initializers/passwordless.rb`: ```ruby Passwordless.configure do |config| config.after_session_save = lambda do |session, request| # Default behavior is # Passwordless::Mailer.sign_in(session).deliver_now # You can change behavior to do something with session model. For example, # SmsApi.send_sms(session.authenticatable.phone_number, session.token) end end ``` ### Token generation By default Passwordless generates short, 6-digit, alpha numeric tokens. You can change the generator using `Passwordless.config.token_generator` to something else that responds to `call(session)` eg.: ```ruby Passwordless.configure do |config| config.token_generator = lambda do |session| "probably-stupid-token-#{session.user_agent}-#{Time.current}" end end ``` Passwordless will keep generating tokens until it finds one that hasn't been used yet. So be sure to use some kind of method where matches are unlikely. ### Timeout and Expiry The _timeout_ is the time by which the generated token and magic link is invalidated. After this the token cannot be used to sign in to your app and the user will need to request a new token. The _expiry_ is the expiration time of the session of a logged in user. Once this is expired, the user is signed out. **Note:** Passwordless' session relies on Rails' own session and so will never live longer than that. To configure your Rails session, in `config/initializers/session_store.rb`: ```ruby Rails.application.config.session_store :cookie_store, expire_after: 1.year, # ... ``` ### Redirection after sign-in By default Passwordless will redirect back to where the user wanted to go _if_ it knows where that is -- so you'll have to help it. `Passwordless::ControllerHelpers` provide a method: ```ruby class ApplicationController < ActionController::Base include Passwordless::ControllerHelpers # <-- Probably already have this! # ... def require_user! return if current_user save_passwordless_redirect_location!(User) # <-- this one! redirect_to root_path, alert: "You are not worthy!" end end ``` This can also be turned off with `Passwordless.config.redirect_back_after_sign_in = false`. ### Looking up the user By default Passwordless uses the `passwordless_with` column to _case insensitively_ fetch the user resource. You can override this by defining a class method `fetch_resource_for_passwordless` in your user model. This method will be called with the down-cased, stripped `email` and should return an `ActiveRecord` instance. ```ruby class User < ApplicationRecord def self.fetch_resource_for_passwordless(email) find_or_create_by(email: email) end end ``` ## Test helpers To help with testing, a set of test helpers are provided. If you are using RSpec, add the following line to your `spec/rails_helper.rb`: ```ruby require "passwordless/test_helpers" ``` If you are using TestUnit, add this line to your `test/test_helper.rb`: ```ruby require "passwordless/test_helpers" ``` Then in your controller, request, and system tests/specs, you can utilize the following methods: ```ruby passwordless_sign_in(user) # signs you in as a user passwordless_sign_out # signs out user ``` ## Security considerations There's no reason that this approach should be less secure than the usual username/password combo. In fact this is most often a more secure option, as users don't get to choose the horrible passwords they can't seem to stop using. In a way, this is just the same as having each user go through "Forgot password" on every login. But be aware that when everyone authenticates via emails, the way you send those mails becomes a weak spot. Email services usually provide a log of all the mails you send so if your email delivery provider account is compromised, every user in the system is as well. (This is the same for "Forgot password".) [Reddit was once compromised](https://thenextweb.com/hardfork/2018/01/05/reddit-bitcoin-cash-stolen-hack/) using this method. Ideally you should set up your email provider to not log these mails. And be sure to turn on non-SMS 2-factor authentication if your provider supports it. ## Alternatives - [OTP JWT](https://github.com/stas/otp-jwt) -- Passwordless JSON Web Tokens ## License MIT