SolidusJwt

This gem gives Solidus stores the ability to authenticate API requests with JSON Web Tokens.

To use this gem, you should have a sound understanding of JSON web tokens. For more information you can visit the Offical JWT Website. It may also be useful to look at ruby-jwt, the library required by this gem.

Installation

Add solidus_jwt to your Gemfile:

gem 'solidus'
gem 'solidus_jwt'

Bundle your dependencies and run the installation generator:

bundle
bundle exec rails g solidus_jwt:install

Configuration

# config/initializers/solidus_jwt.rb

SolidusJwt::Config.configure do |config|
  config.jwt_secret           = 'secret'
  config.allow_spree_api_key  = true
  config.jwt_algorithm        = 'HS256'
  config.jwt_expiration       = 3_600
  config.jwt_options          = { only: %i[email first_name id last_name] }
  config.refresh_expiration   = 2_592_000
end

jwt_secret:

Defaults to Rails.application.secret_key_base. The encryption key, should be kept secret and secure.

allow_spree_api_key:

Defaults to true. When true, the spree_api_key is still accepted as an authentication token along with json web tokens.

jwt_algorithm:

Defaults to HS256. See: https://github.com/jwt/ruby-jwt#algorithms-and-usage for more information on accepted algorithms.

jwt_expiration:

Defaults to 3600 (1 hour). The amount of time in seconds that the token should last for.

jwt_options

Defaults to { only: %i[email first_name id last_name] }. These options are passed into Spree::User#as_json when serializing the token's payload. Keep in mind that the more information included, the larger the token will be. It may be in your best interest to keep it short and simple.

refresh_expiration:

Defaults to 2592000 (30 days). The amount of time in seconds that the token should last for.

Usage

Generating and decoding a token:

SolidusJwt::Config.configure do |config|
  config.jwt_secret = 'secret'
end

user = Spree::User.new email: 'email@example.com', id: 1
token = user.generate_jwt_token(expires_in: 1.hour.to_i) # Expiration is time in seconds
# eyJhbGciOiJIUzI1NiJ9.eyJpZCI6MSwiZW1haWwiOiJlbWFpbEBleGFtcGxlLmNvbSIsInN1YiI6MSwiZXhwIjoxNTcyNTg2NTA3LCJpYXQiOjE1NzI1ODI5MDcsImlzcyI6InNvbGlkdXMifQ.UEmPLClCmOii_5-Qa6fB_ToGavIJYY6PAyfhARitMwI

SolidusJwt.decode(token)
# [
#   {
#     "id"=>1, 
#     "email"=>"email@example.com", 
#     "sub"=>1, 
#     "exp"=>1572586507, 
#     "iat"=>1572582907, 
#     "iss"=>"solidus"
#   },
#   {"alg"=>"HS256"}
# ]

Autenticate through the API

If authenticating through the API, you must have solidus_auth_devise setup because solidus_jwt piggybacks off of the Devise gem. This enables authentication through a single point. If you implement Devise Lockable, then locking is respected both on the front-end as well as on the API.

POST /oauth/token
{
  "username": "user@example.com"
  "password": "secret"
  "grant_type": "password"
}

# { "access_token": "abc.123.efg", "refresh_token": "123456" }

You can now use the access_token to authentication with the Solidus API in place of the spree_api_key.

Matching token to a user

By default, the token matches a user using the Spree::User.for_jwt method. This methods Finds a user by id using the subject claim of the token. If you want to customize how the subject claim is interpreted you can override this method

def self.for_jwt(sub)
  # find_by(id: sub)
  find_by(my_external_id: sub)
end

Obtain a refresh token

To refresh your access token, instead of re-authenticating you can send a refresh token.

POST /oauth/token
{
  "refresh_token": "123456"
  "grant_type": "refresh_token"
}

# { "access_token": "hij.456.klm", "refresh_token": "789abc" }

Invalidate refresh tokens for a user

It is good practice set the lifetime of an access token to be short. In case an access token is compromised, the attacker will only have access for a short time.

To force a user to have to reauthencate rather than using a refresh token, you can do the following:

# Invalidate all refresh tokens for a user
SolidusJwt::Token.invalidate(user)

Distributing a Token Using 'solidus_auth_devise' on front-end:

To have the solidus_auth_devise gem distribute a token back to the client you can do the following:

# app/controllers/application_controller.rb
include SolidusJwt::Distributor::Devise

When a user logs in, the redirect will contain the header X-SPREE-TOKEN.

Testing

First bundle your dependencies, then run rake. rake will default to building the dummy app if it does not exist, then it will run specs, and Rubocop static code analysis. The dummy app can be regenerated by using rake test_app.

bundle
bundle exec rake

When testing your applications integration with this extension you may use it's factories. Simply add this require statement to your spec_helper:

require 'solidus_jwt/factories'

Copyright (c) 2018 [name of extension creator], released under the New BSD License