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Workbench authentication process » History » Version 14

Peter Amstutz, 11/17/2014 08:14 PM

1 1 Peter Amstutz
h1. Workbench authentication process
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# 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.
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# 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.
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# In API server, the 'login' endpoint goes to @UserSessionsController#login@ in the API server.  This redirects to @/auth/joshid?return_to=xxx@
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# In API server, @/auth/joshid@ is intercepted by the "OmniAuth":https://github.com/intridea/omniauth Rack middleware and invokes the @josh_id@ OmniAuth strategy.
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## The @josh_id@ OmniAuth strategy is implemented in @arvados/services/api/lib/josh_id.rb@ and is a subclass of @OmniAuth::Strategies::OAuth2@
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## 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@
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# In sso-provider, @/auth/josh_id/authorize@ is routed to @AuthController#authorize@, and is intercepted by @before_filter :authenticate_user!@ (part of the "devise gem":https://github.com/plataformatec/devise)
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## @devise :omniauthable, :omniauth_providers => [:google]@ configures @sso-provider/app/models/user.rb@
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## @authenticate_user!@ is not explicitly defined but instead monkey patched into the controller in @devise/lib/devise/controllers/helper.rb@
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## @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)
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## 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@ 
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## This calls @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@) 
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# In sso-provider @/users/sign_in@ routes to the SSO @SessionsController#new@ which subclasses @Devise::SessionsController@
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## @SessionsController#new@ redirects to @/users/auth/google@
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# In sso-provider, OmniAuth intercepts @/users/auth/google@ 
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## OmniAuth is configured with a path prefix of @/users/auth@ by devise 
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## @sso-provider/config/initializers/devise.rb@ configures a @:open_id@ omniauth strategy named of 'google'
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## This enters the request phase at @omniauth-open-id/lib/omniauth/strategies/open_id.rb@
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## This creates a rack layer with @Rack::OpenID.new@ (the @rack-openid@ gem) executes it with @call@
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## The Rack layer passes through the request to the underlying @@app@ and checks for a 401 response code, if so it calls @begin_authentication@
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## @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).
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# Google redirects to the sso-server at @/users/auth/google/callback@ after a successful login (after more redirects within Google)
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# In sso-provider, Omniauth intercepts this and calls @callback_phase@ in omniauth-openid
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## The callback phase calls @openid_response@
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## @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.
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## Request handling continues to sso-provider where it routes to @Users::OmniauthCallbacksController#google@
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## 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.
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## The @google@ callback also saves the first_name and last_name of the user.
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## This calls @sign_in_and_redirect@ defined in @devise/lib/devise/controllers/helpers.rb@
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## This calls set_user in Warden, which uses @Warden::SessionSerializer@ to save the user associated with the session
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## 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.
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# 
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h2. Questions
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* What is workbench's "secret_token" for?