debian-mirror-gitlab/lib/api/api_guard.rb
2020-08-09 17:44:08 +05:30

178 lines
6 KiB
Ruby

# frozen_string_literal: true
# Guard API with OAuth 2.0 Access Token
require 'rack/oauth2'
module API
module APIGuard
extend ActiveSupport::Concern
included do |base|
# OAuth2 Resource Server Authentication
use Rack::OAuth2::Server::Resource::Bearer, 'The API' do |request|
# The authenticator only fetches the raw token string
# Must yield access token to store it in the env
request.access_token
end
use AdminModeMiddleware
helpers HelperMethods
install_error_responders(base)
end
class_methods do
# Set the authorization scope(s) allowed for an API endpoint.
#
# A call to this method maps the given scope(s) to the current API
# endpoint class. If this method is called multiple times on the same class,
# the scopes are all aggregated.
def allow_access_with_scope(scopes, options = {})
Array(scopes).each do |scope|
allowed_scopes << Scope.new(scope, options)
end
end
def allowed_scopes
@scopes ||= []
end
end
# Helper Methods for Grape Endpoint
module HelperMethods
include Gitlab::Auth::AuthFinders
def access_token
super || find_personal_access_token_from_http_basic_auth
end
def find_current_user!
user = find_user_from_sources
return unless user
# Sessions are enforced to be unavailable for API calls, so ignore them for admin mode
Gitlab::Auth::CurrentUserMode.bypass_session!(user.id) if Feature.enabled?(:user_mode_in_session)
unless api_access_allowed?(user)
forbidden!(api_access_denied_message(user))
end
user
end
def find_user_from_sources
deploy_token_from_request ||
find_user_from_bearer_token ||
find_user_from_job_token ||
find_user_from_warden
end
private
# An array of scopes that were registered (using `allow_access_with_scope`)
# for the current endpoint class. It also returns scopes registered on
# `API::API`, since these are meant to apply to all API routes.
def scopes_registered_for_endpoint
@scopes_registered_for_endpoint ||=
begin
endpoint_classes = [options[:for].presence, ::API::API].compact
endpoint_classes.reduce([]) do |memo, endpoint|
if endpoint.respond_to?(:allowed_scopes)
memo.concat(endpoint.allowed_scopes)
else
memo
end
end
end
end
def api_access_allowed?(user)
user_allowed_or_deploy_token?(user) && user.can?(:access_api)
end
def api_access_denied_message(user)
Gitlab::Auth::UserAccessDeniedReason.new(user).rejection_message
end
def user_allowed_or_deploy_token?(user)
Gitlab::UserAccess.new(user).allowed? || user.is_a?(DeployToken)
end
end
class_methods do
private
def install_error_responders(base)
error_classes = [Gitlab::Auth::MissingTokenError,
Gitlab::Auth::TokenNotFoundError,
Gitlab::Auth::ExpiredError,
Gitlab::Auth::RevokedError,
Gitlab::Auth::ImpersonationDisabled,
Gitlab::Auth::InsufficientScopeError]
base.__send__(:rescue_from, *error_classes, oauth2_bearer_token_error_handler) # rubocop:disable GitlabSecurity/PublicSend
end
def oauth2_bearer_token_error_handler
proc do |e|
response =
case e
when Gitlab::Auth::MissingTokenError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new
when Gitlab::Auth::TokenNotFoundError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Bad Access Token.")
when Gitlab::Auth::ExpiredError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Token is expired. You can either do re-authorization or token refresh.")
when Gitlab::Auth::RevokedError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Token was revoked. You have to re-authorize from the user.")
when Gitlab::Auth::ImpersonationDisabled
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Token is an impersonation token but impersonation was disabled.")
when Gitlab::Auth::InsufficientScopeError
# FIXME: ForbiddenError (inherited from Bearer::Forbidden of Rack::Oauth2)
# does not include WWW-Authenticate header, which breaks the standard.
Rack::OAuth2::Server::Resource::Bearer::Forbidden.new(
:insufficient_scope,
Rack::OAuth2::Server::Resource::ErrorMethods::DEFAULT_DESCRIPTION[:insufficient_scope],
{ scope: e.scopes })
end
status, headers, body = response.finish
# Grape expects a Rack::Response
# (https://github.com/ruby-grape/grape/commit/c117bff7d22971675f4b34367d3a98bc31c8fc02),
# so we need to recreate the response again even though
# response.finish already does this.
# (https://github.com/nov/rack-oauth2/blob/40c9a99fd80486ccb8de0e4869ae384547c0d703/lib/rack/oauth2/server/abstract/error.rb#L26).
Rack::Response.new(body, status, headers)
end
end
end
class AdminModeMiddleware < ::Grape::Middleware::Base
def after
# Use a Grape middleware since the Grape `after` blocks might run
# before we are finished rendering the `Grape::Entity` classes
Gitlab::Auth::CurrentUserMode.reset_bypass_session! if Feature.enabled?(:user_mode_in_session)
# Explicit nil is needed or the api call return value will be overwritten
nil
end
end
end
end