docbrown/config/initializers/persistent_csrf_token_cookie.rb
rhymes 8407bf9b4e
[deploy] Authentication refactoring: cleanups (#7576)
* Use Devise registry to list available providers

* Cleanups following Devise+Omniauth docs

* More cleanups

* Use helpers

* More cleanups

* Oops, forgot to remove these specs
2020-04-29 10:33:30 -04:00

36 lines
1.5 KiB
Ruby

# Workaround for CSRF protection bug.
#
# https://github.com/rails/rails/issues/21948
# The bug:
# The rails session cookie is not persistent,
# therefore it expires when the page is loaded from cache
# (i.e. when browser restores tabs on restart https://www.youtube.com/watch?v=bKDu0qMT4HM)
# which leads to an `InvalidAuthenticityToken` when the user submits a form from that page.
#
# Workaround:
# We decided to move the CSRF token from the session cookie into a separate persistent cookie.
module ActionController
module RequestForgeryProtection
COOKIE_NAME = :_csrf_token
def real_csrf_token(session)
csrf_token = cookies.encrypted[COOKIE_NAME] || session[:_csrf_token]
csrf_token ||= SecureRandom.base64(AUTHENTICITY_TOKEN_LENGTH)
cookies.encrypted[COOKIE_NAME] ||= {
value: csrf_token,
expires: 1.year.from_now,
httponly: true
}
session[:_csrf_token] = csrf_token
Base64.strict_decode64(csrf_token)
end
end
end
# http://blog.plataformatec.com.br/2013/08/csrf-token-fixation-attacks-in-devise/
# (devise-4.2.0/lib/devise/hooks/csrf_cleaner.rb):
Warden::Manager.after_authentication do |_record, warden, _options|
clean_up_for_winning_strategy = !warden.winning_strategy.respond_to?(:clean_up_csrf?) ||
warden.winning_strategy.clean_up_csrf?
warden.cookies.delete(ActionController::RequestForgeryProtection::COOKIE_NAME) if Devise.clean_up_csrf_token_on_authentication && clean_up_for_winning_strategy
end