Artsy Passport

Wires up the common auth handlers, and related security concerns, for Artsy's Ezel-based apps using passport. Used internally at Artsy to DRY up authentication code.

Breaking changes in 2.0

• The app is now shipped as a single JS file.

Setup

Make sure you first mount session, body parser, and start artsy-xapp.

app.use express.bodyParser()
app.use express.cookieParser('foobar')
app.use express.cookieSession()
artsyXapp.init -> app.listen()

Then mount Artsy Passport passing a big configuration hash.

Values indicate defaults.

app.use artsyPassport

  CurrentUser: # The CurrentUser Backbone model

  # Pass in env vars
  # ----------------
  FACEBOOK_ID: # Facebook app ID
  FACEBOOK_SECRET: # Facebook app secret
  TWITTER_KEY: # Twitter consumer key
  TWITTER_SECRET: # Twitter consumer secret
  TWITTER_KEY: # Twitter consumer key
  TWITTER_SECRET: # Twitter consumer secret
  LINKEDIN_KEY: # Linkedin app key
  LINKEDIN_SECRET: # Linkedin app secret
  ARTSY_ID: # Artsy client id
  ARTSY_SECRET: # Artsy client secret
  ARTSY_URL: # SSL Artsy url e.g. https://artsy.net
  APP_URL: # Url pointing back to your app e.g. http://flare.artsy.net
  SEGMENT_WRITE_KEY: # Segment write key to track signup

  # Defaults you probably don't need to touch
  # -----------------------------------------

  # Social auth
  linkedinPath: '/users/auth/linkedin'
  linkedinCallbackPath: '/users/auth/linkedin/callback'
  facebookPath: '/users/auth/facebook'
  facebookCallbackPath: '/users/auth/facebook/callback'
  twitterPath: '/users/auth/twitter'
  twitterCallbackPath: '/users/auth/twitter/callback'
  twitterLastStepPath: '/users/auth/twitter/email'
  twitterSignupTempEmail: (token) ->
    hash = crypto.createHash('sha1').update(token).digest('hex')
    "#{hash.substr 0, 12}@artsy.tmp"

  # Landing pages
  loginPagePath: '/log_in'
  signupPagePath: '/sign_up'
  settingsPagePath: '/user/edit'
  afterSignupPagePath: '/personalize'

  # Misc
  logoutPath: '/users/sign_out'
  userKeys: [
    'id', 'type', 'name', 'email', 'phone', 'lab_features',
    'default_profile_id', 'has_partner_access', 'collector_level'
  ]

The keys are cased so it's convenient to pass in a configuration hash. A minimal setup could look like this:

app.use artsyPassport _.extend config,
  CurrentUser: CurrentUser

Note: CurrentUser must be a Backbone model with typical get and toJSON methods.

Create a login form pointing to your paths.

h1 Login
pre!= error
a( href=ap.facebookPath ) Login via Facebook
a( href=ap.twitterPath ) Login via Twitter
form( action=ap.loginPagePath, method='POST' )
  h3 Login via Email
  input( name='name' )
  input( name='email' )
  input( name='password' )
  input( type="hidden" name="_csrf" value=csrfToken )
  button( type='submit' ) Login

And maybe a signup form...

h1 Signup
pre!= error
a( href=ap.facebookPath ) Signup via Facebook
a( href=ap.twitterPath ) Signup via Twitter
form( action=ap.signupPagePath, method='POST' )
  h3 Signup via Email
  input( name='name' )
  input( name='email' )
  input( name='password' )
  input( type="hidden" name="_csrf" value=csrfToken )
  button( type='submit' ) Signup

And maybe a settings page for linking accounts...

h2 Linked Accounts
pre!= error
- providers = user.get('authentications').map(function(a) { return a.provider })
if providers.indexOf('facebook') > -1
  | Connected Facebook
else
  a( href=ap.facebookPath ) Connect Facebook
br
if providers.indexOf('twitter') > -1
  | Connected Twitter
else
  a( href=ap.twitterPath ) Connect Twitter
br
if providers.indexOf('linkedin') > -1
  | Connected LinkedIn
else
  a( href=ap.linkedinPath ) Connect LinkedIn

Finally there's this weird "one last step" UI for twitter to store emails after signup.

h1 Just one more step
pre!= error
form( method='post', action=ap.twitterLastStepPath )
  input( type="hidden" name="_csrf" value=csrfToken )
  input.bordered-input( name='email' )
  button( type='submit' ) Join Artsy

Render the pages

{ loginPagePath, signupPagePath, settingsPagePath,
  afterSignupPagePath, twitterLastStepPath } = artsyPassport.options

app.get loginPagePath, (req, res) -> res.render 'login'
app.get signupPagePath, (req, res) -> res.render 'signup'
app.get settingsPagePath, (req, res) -> res.render 'settings'
app.get afterSignupPagePath, (req, res) -> res.render 'personalize'
app.get twitterLastStepPath, (req, res) -> res.render 'twitter_last_step'

Access a logged in Artsy user in a variety of ways...

In your server-side templates

h1 Hello #{user.get('name')}

In your client-side code

CurrentUser = require '../models/current_user.coffee'
sd = require('sharify').data

user = new CurrentUser(sd.CURRENT_USER)

In your routers

app.get '/', (req, res) ->
  res.send 'Hello ' + req.user.get('name')

These forms of user will be null if they're not logged in.

Sanitize Redirect

If you implement a fancier auth flow that involves client-side redirecting back, you may find this helper useful in avoiding "open redirect" attacks.

sanitizeRedirect = require 'artsy-passport/sanitize-redirect'

location.href = sanitizeRedirect "http://artsy.net%0D%0Aattacker.com/"
# Notices the url isn't pointing at artsy.net, so just redirects to /

Contributing

Add a local.artsy.net entry into your /etc/hosts

127.0.0.1 localhost
#...
127.0.0.1 local.artsy.net

Install node modules npm install then write a ./config.coffee that looks something like this:

module.exports =
  FACEBOOK_ID: ''
  FACEBOOK_SECRET: ''
  TWITTER_KEY: ''
  TWITTER_SECRET: ''
  LINKEDIN_KEY: ''
  LINKEDIN_SECRET: ''
  ARTSY_ID: ''
  ARTSY_SECRET: ''
  ARTSY_URL: 'https://api.artsy.net'
  APP_URL: 'http://local.artsy.net:4000'
  # An Artsy user that's linked to Facebook and Twitter
  ARTSY_EMAIL: '[email protected]'
  ARTSY_PASSWORD: ''
  TWITTER_EMAIL: '[email protected]'
  TWITTER_PASSWORD: ''
  FACEBOOK_EMAIL: '[email protected]'
  FACEBOOK_PASSWORD: ''

Then you can check the example by running npm run example and opening localhost:4000.

The tests are a combination of integration and middleware unit tests. To run the whole suite use npm test.