import os import pathlib from functools import partial from time import monotonic import jinja2 from flask import ( current_app, flash, g, make_response, redirect, render_template, request, session, url_for, ) from flask.globals import _lookup_req_object, _request_ctx_stack from flask_login import LoginManager, current_user from flask_wtf import CSRFProtect from flask_wtf.csrf import CSRFError from gds_metrics import GDSMetrics from govuk_frontend_jinja.flask_ext import init_govuk_frontend from itsdangerous import BadSignature from notifications_python_client.errors import HTTPError from notifications_utils import logging, request_helper from notifications_utils.formatters import ( formatted_list, get_lines_with_normalised_whitespace, ) from notifications_utils.recipients import format_phone_number_human_readable from notifications_utils.sanitise_text import SanitiseASCII from werkzeug.exceptions import HTTPException as WerkzeugHTTPException from werkzeug.exceptions import abort from werkzeug.local import LocalProxy from app import proxy_fix, webauthn_server from app.asset_fingerprinter import asset_fingerprinter from app.config import configs from app.custom_auth import CustomBasicAuth from app.extensions import antivirus_client, redis_client, zendesk_client from app.formatters import ( convert_to_boolean, format_auth_type, format_billions, format_date, format_date_human, format_date_normal, format_date_numeric, format_date_short, format_datetime, format_datetime_24h, format_datetime_human, format_datetime_normal, format_datetime_relative, format_datetime_short, format_day_of_week, format_delta, format_delta_days, format_list_items, format_mobile_network, format_notification_status, format_notification_status_as_field_status, format_notification_status_as_time, format_notification_status_as_url, format_notification_type, format_number_in_pounds_as_currency, format_thousands, format_time, format_yes_no, id_safe, iteration_count, linkable_name, message_count, message_count_label, message_count_noun, nl2br, recipient_count, recipient_count_label, round_to_significant_figures, square_metres_to_square_miles, valid_phone_number, ) from app.models.organisation import Organisation from app.models.service import Service from app.models.user import AnonymousUser, User from app.navigation import ( CaseworkNavigation, HeaderNavigation, MainNavigation, OrgNavigation, ) from app.notify_client import InviteTokenError from app.notify_client.api_key_api_client import api_key_api_client from app.notify_client.billing_api_client import billing_api_client from app.notify_client.complaint_api_client import complaint_api_client from app.notify_client.contact_list_api_client import contact_list_api_client from app.notify_client.email_branding_client import email_branding_client from app.notify_client.events_api_client import events_api_client from app.notify_client.inbound_number_client import inbound_number_client from app.notify_client.invite_api_client import invite_api_client from app.notify_client.job_api_client import job_api_client from app.notify_client.letter_branding_client import letter_branding_client from app.notify_client.letter_jobs_client import letter_jobs_client from app.notify_client.notification_api_client import notification_api_client from app.notify_client.org_invite_api_client import org_invite_api_client from app.notify_client.organisations_api_client import organisations_client from app.notify_client.performance_dashboard_api_client import ( performance_dashboard_api_client, ) from app.notify_client.platform_stats_api_client import ( platform_stats_api_client, ) from app.notify_client.provider_client import provider_client from app.notify_client.service_api_client import service_api_client from app.notify_client.status_api_client import status_api_client from app.notify_client.template_folder_api_client import ( template_folder_api_client, ) from app.notify_client.template_statistics_api_client import ( template_statistics_client, ) from app.notify_client.upload_api_client import upload_api_client from app.notify_client.user_api_client import user_api_client from app.url_converters import ( LetterFileExtensionConverter, SimpleDateTypeConverter, TemplateTypeConverter, TicketTypeConverter, ) login_manager = LoginManager() csrf = CSRFProtect() metrics = GDSMetrics() basic_auth = CustomBasicAuth() # The current service attached to the request stack. def _get_current_service(): return _lookup_req_object('service') current_service = LocalProxy(_get_current_service) # The current organisation attached to the request stack. current_organisation = LocalProxy(partial(_lookup_req_object, 'organisation')) navigation = { 'casework_navigation': CaseworkNavigation(), 'main_navigation': MainNavigation(), 'header_navigation': HeaderNavigation(), 'org_navigation': OrgNavigation(), } def create_app(application): notify_environment = os.environ['NOTIFY_ENVIRONMENT'] application.config.from_object(configs[notify_environment]) asset_fingerprinter._asset_root = application.config['ASSET_PATH'] init_app(application) if 'extensions' not in application.jinja_options: application.jinja_options['extensions'] = [] init_govuk_frontend(application) init_jinja(application) for client in ( # Gubbins # Note, metrics purposefully first so we start measuring response times as early as possible before any # other `app.before_request` handlers (introduced by any of these clients) are processed (which would # otherwise mean we aren't measuring the full response time) metrics, csrf, login_manager, proxy_fix, request_helper, # API clients api_key_api_client, billing_api_client, contact_list_api_client, complaint_api_client, email_branding_client, events_api_client, inbound_number_client, invite_api_client, job_api_client, letter_branding_client, letter_jobs_client, notification_api_client, org_invite_api_client, organisations_client, performance_dashboard_api_client, platform_stats_api_client, provider_client, service_api_client, status_api_client, template_folder_api_client, template_statistics_client, upload_api_client, user_api_client, # External API clients antivirus_client, redis_client, zendesk_client, ): client.init_app(application) logging.init_app(application) webauthn_server.init_app(application) login_manager.login_view = 'main.sign_in' login_manager.login_message_category = 'default' login_manager.session_protection = None login_manager.anonymous_user = AnonymousUser setup_basic_auth(application) # make sure we handle unicode correctly redis_client.redis_store.decode_responses = True setup_blueprints(application) add_template_filters(application) register_errorhandlers(application) setup_event_handlers() def init_app(application): application.after_request(useful_headers_after_request) application.before_request(load_service_before_request) application.before_request(load_organisation_before_request) application.before_request(request_helper.check_proxy_header_before_request) font_paths = [ str(item)[len(asset_fingerprinter._filesystem_path):] for item in pathlib.Path(asset_fingerprinter._filesystem_path).glob('fonts/*.woff2') ] @application.context_processor def _attach_current_service(): return {'current_service': current_service} @application.context_processor def _attach_current_organisation(): return {'current_org': current_organisation} @application.context_processor def _attach_current_user(): return {'current_user': current_user} @application.context_processor def _nav_selected(): return navigation @application.before_request def record_start_time(): g.start = monotonic() g.endpoint = request.endpoint @application.context_processor def inject_global_template_variables(): return { 'asset_path': application.config['ASSET_PATH'], 'header_colour': application.config['HEADER_COLOUR'], 'asset_url': asset_fingerprinter.get_url, 'font_paths': font_paths, } application.url_map.converters['uuid'].to_python = lambda self, value: value application.url_map.converters['template_type'] = TemplateTypeConverter application.url_map.converters['ticket_type'] = TicketTypeConverter application.url_map.converters['letter_file_extension'] = LetterFileExtensionConverter application.url_map.converters['simple_date'] = SimpleDateTypeConverter @login_manager.user_loader def load_user(user_id): return User.from_id(user_id) def make_session_permanent(): """ Make sessions permanent. By permanent, we mean "admin app sets when it expires". Normally the cookie would expire whenever you close the browser. With this, the session expiry is set in `config['PERMANENT_SESSION_LIFETIME']` (20 hours) and is refreshed after every request. IE: you will be logged out after twenty hours of inactivity. We don't _need_ to set this every request (it's saved within the cookie itself under the `_permanent` flag), only when you first log in/sign up/get invited/etc, but we do it just to be safe. For more reading, check here: https://stackoverflow.com/questions/34118093/flask-permanent-session-where-to-define-them """ session.permanent = True def load_service_before_request(): if '/static/' in request.url: _request_ctx_stack.top.service = None return if _request_ctx_stack.top is not None: _request_ctx_stack.top.service = None if request.view_args: service_id = request.view_args.get('service_id', session.get('service_id')) else: service_id = session.get('service_id') if service_id: try: _request_ctx_stack.top.service = Service( service_api_client.get_service(service_id)['data'] ) except HTTPError as exc: # if service id isn't real, then 404 rather than 500ing later because we expect service to be set if exc.status_code == 404: abort(404) else: raise def load_organisation_before_request(): if '/static/' in request.url: _request_ctx_stack.top.organisation = None return if _request_ctx_stack.top is not None: _request_ctx_stack.top.organisation = None if request.view_args: org_id = request.view_args.get('org_id') if org_id: try: _request_ctx_stack.top.organisation = Organisation.from_id(org_id) except HTTPError as exc: # if org id isn't real, then 404 rather than 500ing later because we expect org to be set if exc.status_code == 404: abort(404) else: raise def save_service_or_org_after_request(response): # Only save the current session if the request is 200 service_id = request.view_args.get('service_id', None) if request.view_args else None organisation_id = request.view_args.get('org_id', None) if request.view_args else None if response.status_code == 200: if service_id: session['service_id'] = service_id session['organisation_id'] = None elif organisation_id: session['service_id'] = None session['organisation_id'] = organisation_id return response # https://www.owasp.org/index.php/List_of_useful_HTTP_headers def useful_headers_after_request(response): response.headers.add('X-Frame-Options', 'deny') response.headers.add('X-Content-Type-Options', 'nosniff') response.headers.add('X-XSS-Protection', '1; mode=block') response.headers.add('Content-Security-Policy', ( "default-src 'self' {asset_domain} 'unsafe-inline';" "script-src 'self' {asset_domain} *.google-analytics.com 'unsafe-inline' 'unsafe-eval' data:;" "connect-src 'self' *.google-analytics.com;" "object-src 'self';" "font-src 'self' {asset_domain} data:;" "img-src 'self' {asset_domain} *.tile.openstreetmap.org *.google-analytics.com" " *.notifications.service.gov.uk {logo_domain} data:;" "frame-src 'self' www.youtube-nocookie.com;".format( asset_domain=current_app.config['ASSET_DOMAIN'], logo_domain=current_app.config['LOGO_CDN_DOMAIN'], ) )) response.headers.add('Link', ( '<{asset_url}>; rel=dns-prefetch, <{asset_url}>; rel=preconnect'.format( asset_url=f'https://{current_app.config["ASSET_DOMAIN"]}' ) )) if 'Cache-Control' in response.headers: del response.headers['Cache-Control'] response.headers.add( 'Cache-Control', 'no-store, no-cache, private, must-revalidate') for key, value in response.headers: response.headers[key] = SanitiseASCII.encode(value) return response def register_errorhandlers(application): # noqa (C901 too complex) def _error_response(error_code, error_page_template=None): if error_page_template is None: error_page_template = error_code resp = make_response(render_template("error/{0}.html".format(error_page_template)), error_code) return useful_headers_after_request(resp) @application.errorhandler(HTTPError) def render_http_error(error): application.logger.warning("API {} failed with status {} message {}".format( error.response.url if error.response else 'unknown', error.status_code, error.message )) error_code = error.status_code if error_code not in [401, 404, 403, 410]: # probably a 500 or 503. # it might be a 400, which we should handle as if it's an internal server error. If the API might # legitimately return a 400, we should handle that within the view or the client that calls it. application.logger.exception("API {} failed with status {} message {}".format( error.response.url if error.response else 'unknown', error.status_code, error.message )) error_code = 500 return _error_response(error_code) @application.errorhandler(400) def handle_client_error(error): # This is tripped if we call `abort(400)`. application.logger.exception('Unhandled 400 client error') return _error_response(400, error_page_template=500) @application.errorhandler(410) def handle_gone(error): return _error_response(410) @application.errorhandler(404) def handle_not_found(error): return _error_response(404) @application.errorhandler(403) def handle_not_authorized(error): return _error_response(403) @application.errorhandler(401) def handle_no_permissions(error): return _error_response(401) @application.errorhandler(BadSignature) def handle_bad_token(error): # if someone has a malformed token flash('There’s something wrong with the link you’ve used.') return _error_response(404) @application.errorhandler(CSRFError) def handle_csrf(reason): application.logger.warning('csrf.error_message: {}'.format(reason)) if 'user_id' not in session: application.logger.warning( u'csrf.session_expired: Redirecting user to log in page' ) return application.login_manager.unauthorized() application.logger.warning( u'csrf.invalid_token: Aborting request, user_id: {user_id}', extra={'user_id': session['user_id']}) return _error_response(400, error_page_template=500) @application.errorhandler(405) def handle_method_not_allowed(error): return _error_response(405, error_page_template=500) @application.errorhandler(WerkzeugHTTPException) def handle_http_error(error): if error.code == 301: # PermanentRedirect exception return error return _error_response(error.code) @application.errorhandler(InviteTokenError) def handle_bad_invite_token(error): flash(str(error)) return redirect(url_for('main.sign_in')) @application.errorhandler(500) @application.errorhandler(Exception) def handle_bad_request(error): current_app.logger.exception(error) # We want the Flask in browser stacktrace if current_app.config.get('DEBUG', None): raise error return _error_response(500) def setup_blueprints(application): """ There are three blueprints: status_blueprint, no_cookie_blueprint, and main_blueprint. main_blueprint is the default for everything. status_blueprint is only for the status page - unauthenticated, unstyled, no cookies, etc. no_cookie_blueprint is for subresources (things loaded asynchronously) that we might be concerned are setting cookies unnecessarily and potentially getting in to strange race conditions and overwriting other cookies, as we've seen in the send message flow. Currently, this includes letter template previews, and the iframe from the platform admin email branding preview pages. This notably doesn't include the *.json ajax endpoints. If we included them in this, the cookies wouldn't be updated, including the expiration date. If you have a dashboard open and in focus it'll refresh the expiration timer every two seconds, and you will never log out, which is behaviour we want to preserve. """ from app.main import main as main_blueprint from app.main import no_cookie as no_cookie_blueprint from app.status import status as status_blueprint main_blueprint.before_request(make_session_permanent) main_blueprint.after_request(save_service_or_org_after_request) application.register_blueprint(main_blueprint) # no_cookie_blueprint specifically doesn't have `make_session_permanent` or `save_service_or_org_after_request` application.register_blueprint(no_cookie_blueprint) application.register_blueprint(status_blueprint) def setup_event_handlers(): from flask_login import user_logged_in from app.event_handlers import on_user_logged_in user_logged_in.connect(on_user_logged_in) def add_template_filters(application): for fn in [ format_auth_type, format_billions, format_datetime, format_datetime_24h, format_datetime_normal, format_datetime_short, format_time, valid_phone_number, linkable_name, format_date, format_date_human, format_date_normal, format_date_numeric, format_date_short, format_datetime_human, format_datetime_relative, format_day_of_week, format_delta, format_delta_days, format_notification_status, format_notification_type, format_notification_status_as_time, format_notification_status_as_field_status, format_notification_status_as_url, format_number_in_pounds_as_currency, formatted_list, get_lines_with_normalised_whitespace, nl2br, format_phone_number_human_readable, format_thousands, id_safe, convert_to_boolean, format_list_items, iteration_count, recipient_count, recipient_count_label, round_to_significant_figures, message_count_label, message_count, message_count_noun, format_mobile_network, format_yes_no, square_metres_to_square_miles, ]: application.add_template_filter(fn) def init_jinja(application): repo_root = os.path.abspath(os.path.join(os.path.dirname(__file__), '..')) template_folders = [ os.path.join(repo_root, 'app/templates'), os.path.join(repo_root, 'app/templates/vendor/govuk-frontend'), ] jinja_loader = jinja2.FileSystemLoader(template_folders) application.jinja_loader = jinja_loader def setup_basic_auth(application): application.basic_auth = CustomBasicAuth(application)