247 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			Ruby
		
	
	
	
			
		
		
	
	
			247 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			Ruby
		
	
	
	
| # frozen_string_literal: true
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| 
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| # Guard API with OAuth 2.0 Access Token
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| 
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| require 'rack/oauth2'
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| 
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| module API
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|   module APIGuard
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|     extend ActiveSupport::Concern
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|     include Gitlab::Utils::StrongMemoize
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| 
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|     included do |base|
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|       # OAuth2 Resource Server Authentication
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|       use Rack::OAuth2::Server::Resource::Bearer, 'The API' do |request|
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|         # The authenticator only fetches the raw token string
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| 
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|         # Must yield access token to store it in the env
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|         request.access_token
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|       end
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| 
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|       use AdminModeMiddleware
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|       use ResponseCoercerMiddleware
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| 
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|       helpers HelperMethods
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| 
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|       install_error_responders(base)
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|     end
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| 
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|     class_methods do
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|       # Set the authorization scope(s) allowed for an API endpoint.
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|       #
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|       # A call to this method maps the given scope(s) to the current API
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|       # endpoint class. If this method is called multiple times on the same class,
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|       # the scopes are all aggregated.
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|       def allow_access_with_scope(scopes, options = {})
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|         Array(scopes).each do |scope|
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|           allowed_scopes << Scope.new(scope, options)
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|         end
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|       end
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| 
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|       def allowed_scopes
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|         @scopes ||= []
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|       end
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|     end
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| 
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|     # Helper Methods for Grape Endpoint
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|     module HelperMethods
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|       include Gitlab::Auth::AuthFinders
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| 
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|       def access_token
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|         super || find_personal_access_token_from_http_basic_auth
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|       end
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| 
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|       def find_current_user!
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|         user = find_user_from_sources
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|         return unless user
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| 
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|         if user.is_a?(User) && Gitlab::CurrentSettings.admin_mode
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|           # Sessions are enforced to be unavailable for API calls, so ignore them for admin mode
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|           Gitlab::Auth::CurrentUserMode.bypass_session!(user.id)
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|         end
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| 
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|         unless api_access_allowed?(user)
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|           forbidden!(api_access_denied_message(user))
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|         end
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| 
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|         user
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|       end
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| 
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|       def find_user_from_sources
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|         strong_memoize(:find_user_from_sources) do
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|           if try(:namespace_inheritable, :authentication)
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|             user_from_namespace_inheritable ||
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|               user_from_warden
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|           else
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|             deploy_token_from_request ||
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|               find_user_from_bearer_token ||
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|               find_user_from_job_token ||
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|               user_from_warden
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|           end
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|         end
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|       end
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| 
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|       private
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| 
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|       # An array of scopes that were registered (using `allow_access_with_scope`)
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|       # for the current endpoint class. It also returns scopes registered on
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|       # `API::API`, since these are meant to apply to all API routes.
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|       def scopes_registered_for_endpoint
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|         @scopes_registered_for_endpoint ||=
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|           begin
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|             endpoint_classes = [options[:for].presence, ::API::API].compact
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|             endpoint_classes.reduce([]) do |memo, endpoint|
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|               if endpoint.respond_to?(:allowed_scopes)
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|                 memo.concat(endpoint.allowed_scopes)
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|               else
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|                 memo
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|               end
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|             end
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|           end
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|       end
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| 
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|       def api_access_allowed?(user)
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|         user_allowed_or_deploy_token?(user) && user.can?(:access_api)
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|       end
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| 
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|       def api_access_denied_message(user)
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|         Gitlab::Auth::UserAccessDeniedReason.new(user).rejection_message
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|       end
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| 
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|       def user_allowed_or_deploy_token?(user)
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|         Gitlab::UserAccess.new(user).allowed? || user.is_a?(DeployToken)
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|       end
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| 
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|       def user_from_warden
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|         user = find_user_from_warden
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| 
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|         return unless user
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|         return if two_factor_required_but_not_setup?(user)
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| 
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|         user
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|       end
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| 
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|       def two_factor_required_but_not_setup?(user)
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|         verifier = Gitlab::Auth::TwoFactorAuthVerifier.new(user)
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| 
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|         if verifier.two_factor_authentication_required? && verifier.current_user_needs_to_setup_two_factor?
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|           verifier.two_factor_grace_period_expired?
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|         else
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|           false
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|         end
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|       end
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|     end
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| 
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|     class_methods do
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|       private
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| 
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|       def install_error_responders(base)
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|         error_classes = [Gitlab::Auth::MissingTokenError,
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|                          Gitlab::Auth::TokenNotFoundError,
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|                          Gitlab::Auth::ExpiredError,
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|                          Gitlab::Auth::RevokedError,
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|                          Gitlab::Auth::ImpersonationDisabled,
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|                          Gitlab::Auth::InsufficientScopeError]
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| 
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|         base.__send__(:rescue_from, *error_classes, oauth2_bearer_token_error_handler) # rubocop:disable GitlabSecurity/PublicSend
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|       end
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| 
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|       def oauth2_bearer_token_error_handler
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|         proc do |e|
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|           response =
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|             case e
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|             when Gitlab::Auth::MissingTokenError
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|               Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new
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| 
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|             when Gitlab::Auth::TokenNotFoundError
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|               Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
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|                 :invalid_token,
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|                 "Bad Access Token.")
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| 
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|             when Gitlab::Auth::ExpiredError
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|               Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
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|                 :invalid_token,
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|                 "Token is expired. You can either do re-authorization or token refresh.")
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| 
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|             when Gitlab::Auth::RevokedError
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|               Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
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|                 :invalid_token,
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|                 "Token was revoked. You have to re-authorize from the user.")
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| 
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|             when Gitlab::Auth::ImpersonationDisabled
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|               Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
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|                 :invalid_token,
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|                 "Token is an impersonation token but impersonation was disabled.")
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| 
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|             when Gitlab::Auth::InsufficientScopeError
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|               # FIXME: ForbiddenError (inherited from Bearer::Forbidden of Rack::Oauth2)
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|               # does not include WWW-Authenticate header, which breaks the standard.
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|               Rack::OAuth2::Server::Resource::Bearer::Forbidden.new(
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|                 :insufficient_scope,
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|                 Rack::OAuth2::Server::Resource::ErrorMethods::DEFAULT_DESCRIPTION[:insufficient_scope],
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|                 { scope: e.scopes })
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|             end
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| 
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|           status, headers, body = response.finish
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| 
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|           # Grape expects a Rack::Response
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|           # (https://github.com/ruby-grape/grape/commit/c117bff7d22971675f4b34367d3a98bc31c8fc02),
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|           # so we need to recreate the response again even though
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|           # response.finish already does this.
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|           # (https://github.com/nov/rack-oauth2/blob/40c9a99fd80486ccb8de0e4869ae384547c0d703/lib/rack/oauth2/server/abstract/error.rb#L26).
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|           Rack::Response.new(body, status, headers)
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|         end
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|       end
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|     end
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| 
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|     # Prior to Rack v2.1.x, returning a body of [nil] or [201] worked
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|     # because the body was coerced to a string. However, this no longer
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|     # works in Rack v2.1.0+. The Rack spec
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|     # (https://github.com/rack/rack/blob/master/SPEC.rdoc#the-body-)
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|     # says:
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|     #
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|     # The Body must respond to `each` and must only yield String values
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|     #
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|     # Because it's easy to return the wrong body type, this middleware
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|     # will:
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|     #
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|     # 1. Inspect each element of the body if it is an Array.
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|     # 2. Coerce each value to a string if necessary.
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|     # 3. Flag a test and development error.
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|     class ResponseCoercerMiddleware < ::Grape::Middleware::Base
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|       def call(env)
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|         response = super(env)
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| 
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|         status = response[0]
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|         body = response[2]
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| 
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|         return response if Rack::Utils::STATUS_WITH_NO_ENTITY_BODY[status]
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|         return response unless body.is_a?(Array)
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| 
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|         body.map! do |part|
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|           if part.is_a?(String)
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|             part
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|           else
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|             err = ArgumentError.new("The response body should be a String, but it is of type #{part.class}")
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|             Gitlab::ErrorTracking.track_and_raise_for_dev_exception(err)
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|             part.to_s
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|           end
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|         end
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| 
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|         response
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|       end
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|     end
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| 
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|     class AdminModeMiddleware < ::Grape::Middleware::Base
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|       def after
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|         # Use a Grape middleware since the Grape `after` blocks might run
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|         # before we are finished rendering the `Grape::Entity` classes
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|         Gitlab::Auth::CurrentUserMode.reset_bypass_session! if Gitlab::CurrentSettings.admin_mode
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| 
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|         # Explicit nil is needed or the api call return value will be overwritten
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|         nil
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|       end
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|     end
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|   end
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| end
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