discourse/lib/middleware/omniauth_bypass_middleware.rb
David Taylor c88303bb27
DEV: Relax auth provider registration restrictions for plugins (#24095)
In the past we would build the stack of Omniauth providers at boot, which meant that plugins had to register any authenticators in the root of their plugin.rb (i.e. not in an `after_initialize` block). This could be frustrating because many features are not available that early in boot (e.g. Zeitwerk autoloading).

Now that we build the omniauth strategy stack 'just in time', it is safe for plugins to register their auth methods in an `after_initialize` block. This commit relaxes the old restrictions so that plugin authors have the option to move things around.
2023-10-26 10:54:30 +01:00

68 lines
2.6 KiB
Ruby

# frozen_string_literal: true
require "csrf_token_verifier"
# omniauth loves spending lots cycles in its magic middleware stack
# this middleware bypasses omniauth middleware and only hits it when needed
class Middleware::OmniauthBypassMiddleware
class AuthenticatorDisabled < StandardError
end
def initialize(app, options = {})
@app = app
OmniAuth.config.before_request_phase do |env|
request = ActionDispatch::Request.new(env)
# Check for CSRF token in POST requests
CSRFTokenVerifier.new.call(env) if request.request_method.downcase.to_sym != :get
# If the user is trying to reconnect to an existing account, store in session
request.session[:auth_reconnect] = !!request.params["reconnect"]
# If the client provided an origin, store in session to redirect back
request.session[:destination_url] = request.params["origin"]
end
end
def call(env)
if env["PATH_INFO"].start_with?("/auth")
begin
# When only one provider is enabled, assume it can be completely trusted, and allow GET requests
only_one_provider =
!SiteSetting.enable_local_logins && Discourse.enabled_authenticators.length == 1
OmniAuth.config.allowed_request_methods = only_one_provider ? %i[get post] : [:post]
omniauth =
OmniAuth::Builder.new(@app) do
Discourse.enabled_authenticators.each do |authenticator|
authenticator.register_middleware(self)
end
end
omniauth.call(env)
rescue AuthenticatorDisabled => e
# Authenticator is disabled, pretend it doesn't exist and pass request to app
@app.call(env)
rescue OAuth::Unauthorized => e
# OAuth1 (i.e. Twitter) makes a web request during the setup phase
# If it fails, Omniauth does not handle the error. Handle it here
env["omniauth.error.type"] ||= "request_error"
Rails.logger.error "Authentication failure! request_error: #{e.class}, #{e.message}"
OmniAuth::FailureEndpoint.call(env)
rescue JWT::InvalidIatError => e
# Happens for openid-connect (including google) providers, when the server clock is wrong
env["omniauth.error.type"] ||= "invalid_iat"
Rails.logger.error "Authentication failure! invalid_iat: #{e.class}, #{e.message}"
OmniAuth::FailureEndpoint.call(env)
rescue CSRFTokenVerifier::InvalidCSRFToken => e
# Happens when CSRF token is missing from request
env["omniauth.error.type"] ||= "csrf_detected"
OmniAuth::FailureEndpoint.call(env)
end
else
@app.call(env)
end
end
end