Workbench authentication process » History » Revision 14
Revision 13 (Peter Amstutz, 11/17/2014 07:24 PM) → Revision 14/26 (Peter Amstutz, 11/17/2014 08:14 PM)
h1. Workbench authentication process
# In workbench, when the user goes to a page, it checks for a session or @?api_token=xxx@ in the URL for the API token. If no API token is found, the user is directed to the workbench "welcome" page.
# In workbench, the "welcome" page has a "log in" button that directs the user to the API server login URL, with a @?return_to=xxx@ link embedded in the URL.
# In API server, the 'login' endpoint goes to @UserSessionsController#login@ in the API server. This redirects to @/auth/joshid?return_to=xxx@
# In API server, @/auth/joshid@ is intercepted by the "OmniAuth":https://github.com/intridea/omniauth Rack middleware and invokes the @josh_id@ OmniAuth strategy.
## The @josh_id@ OmniAuth strategy is implemented in @arvados/services/api/lib/josh_id.rb@ and is a subclass of @OmniAuth::Strategies::OAuth2@
## OmniAuth starts the "request_phase" of @OmniAuth::Strategies::OAuth2@. This redirects to @#{options[:custom_provider_url]}/auth/josh_id/authorize@ using CUSTOM_PROVIDER_URL defined in @arvados/services/api/config/initializers/omniauth.rb@
# In sso-provider, @/auth/josh_id/authorize@ @/auth/josh_id@ is routed to @AuthController#authorize@, and is intercepted by @before_filter :authenticate_user!@ (part of the "devise gem":https://github.com/plataformatec/devise)
## @devise :omniauthable, :omniauth_providers => [:google]@ configures @sso-provider/app/models/user.rb@
## @authenticate_user!@ is not explicitly defined but instead monkey patched into the controller in @devise/lib/devise/controllers/helper.rb@
## @authenticate_user!@ calls @warden.authenticate!@ (@warden/lib/warden/proxy.rb@) with a scope of @:user@ ("warden":https://github.com/hassox/warden is another Rack-based authentication gem)
## Warden proxy tries the TokenAuthenticatable and DatabaseAuthenticatable strategies, but these strategies fail and it raises a :warden exception. This causes it to call @failure_app@ which is set up in @devise/lib/devise.rb@ to be @Devise::Delegator.new@
## This calls maps to @devise/lib/devise/failure_app.rb@ which saves the attempted path in the session ("user_return_to") using @store_location!@, then redirects to @new_user_session_path@ (@/users/sign_in@)
# In sso-provider the new_user_session_path @/users/sign_in@ which routes to the SSO @SessionsController#new@ which subclasses @Devise::SessionsController@
## # In sso-provider, @SessionsController#new@ redirects to @/users/auth/google@
# In sso-provider, OmniAuth intercepts @/users/auth/google@
## OmniAuth is configured with a path prefix of @/users/auth@ by devise
## @sso-provider/config/initializers/devise.rb@ configures a @:open_id@ omniauth strategy named of 'google'
## This enters the request phase at @omniauth-open-id/lib/omniauth/strategies/open_id.rb@
## This creates a rack layer with @Rack::OpenID.new@ (the @rack-openid@ gem) executes it with @call@
## The Rack layer passes through the request to the underlying @@app@ and checks for a 401 response code, if so it calls @begin_authentication@
## @begin_authentication@ constructs an @::OpenID::Consumer@ object and calls redirects to @open_id_redirect_url@, which finally takes us to a Google login page (after some redirects within Google).
# Google redirects to the sso-server at @/users/auth/google/callback@ after a successful login (after more redirects within Google)
# In sso-provider, Omniauth intercepts this and calls @callback_phase@ in omniauth-openid
## The callback phase calls @openid_response@
## @openid_response@ creates a rack layer with @Rack::OpenID.new@ (the @rack-openid@ gem) executes it with @call@. This provisions the Rack environment with info from the OpenID callback.
## Request handling continues to sso-provider where it routes to @Users::OmniauthCallbacksController#google@
## This calls @find_for_open_id@ on the @User@ model which finds a user record with a matching identity url, or creates and saves a new user record with the identity url.
## The @google@ callback also saves the first_name and last_name of the user.
## This calls @sign_in_and_redirect@ defined in @devise/lib/devise/controllers/helpers.rb@
## This calls set_user in Warden, which uses @Warden::SessionSerializer@ to save the user associated with the session
## This redirects to @stored_location_for@ which returns the value of @user_return_to@ in the session, which is @/auth/josh_id/authorize@ from step 5.
#
@open_id_redirect_url@
h2. Questions
* What is workbench's "secret_token" for?