def xsrf_protected(non_xsrf_protected_methods: List[str] = config.get_setting(
'NON_XSRF_PROTECTED_METHODS')):
"""
Decorator to validate XSRF tokens for any methods but GET, HEAD, OPTIONS.
:param non_xsrf_protected_methods: List of methods (lowercase)
defaults to list from settings (get, head, options)
"""
def decorated(func):
@wraps(func)
def decorator(*args, **kwargs):
if flask.request.method.lower() in non_xsrf_protected_methods:
# Generate XSRF token
token = generate_xsrf_token()
flask.current_app.jinja_env.globals['xsrf_token'] = token
@flask.after_this_request
def add_cookie(response):
response.set_cookie('XSRF-TOKEN', token)
return response
return func(*args, **kwargs)
else:
# Validate XSRF token
token = flask.request.form.get('xsrf')
if not token:
raise XSRFError("XSRF token required but not given.")
validate_xsrf_token(token)
return func(*args, **kwargs)
return decorator
return decorated
def add_report_to_headers(response):
"""
Generate the Report-To header to be added to a response.
:param response: The response our app has generated which requires headers.
:return: The response with the required headers.
"""
response.headers['Report-To'] = json.dumps(
config.get_setting('REPORT_TO_HEADER'))
return response
def get_base_task(self) -> dict:
"""
Generate the base task body.
This method is provided as a convenient way of overriding the
default body if it requires more complexity than updating a
setting. The default assumes this is being run in App Engine.
This body is supposed to be updated later with the task payload
and URI.
:return: The base task body.
"""
return config.get_setting("CLOUD_TASKS_BODY")
def setup_app_config(self, app: Flask) -> Flask:
"""
Setup the configuration for the Flask app.
This method is meant to be overridden in the case
that a Flask app needs extra configuration.
By default it sets the app Secret Key.
:param Flask app: The Flask app that requires configuring.
:return: The configured Flask app.
:rtype: Flask
"""
app.secret_key = config.get_setting('SECRET_KEY')
return app
def get_task_queue(self):
"""
Generate a queue object to create tasks with.
This is meant as an easy way to override the method for generating
a queue object for which we make tasks with.
"""
try:
queue_settings = config.get_setting(self.QUEUE_SETTINGS_NAME)
except AttributeError:
raise AttributeError(
f"{self.QUEUE_SETTINGS_NAME} setting not defined. "
f"For {self.__module__}.{self.__name__} to work the "
f"{self.QUEUE_SETTINGS_NAME} setting must be defined.")
return TASK_CLIENT.queue_path(**queue_settings)
def add_csp_headers(response):
"""
Generate CSP Headers to be added to a response.
The CSP headers are generated by inspecting the CSP_CONFIG object
in the settings module.
:param response: The response our app has generated which requires headers.
:return: The response with the required headers.
"""
csp_headers = '; '.join(
f'{key} {value}'
for key, value in config.get_setting('CSP_CONFIG').items())
response.headers['Content-Security-Policy'] = csp_headers
return response
def validate_xsrf_token(token):
"""
Validate a token against the current session token
:param token: Token to validate (should be serialized)
:return True/False
"""
serializer = URLSafeTimedSerializer(flask.current_app.secret_key)
try:
token = serializer.loads(token,
max_age=config.get_setting('XSRF_TIME_LIMIT'))
except SignatureExpired:
raise XSRFError("XSRF token has expired.")
except BadData:
raise XSRFError("XSRF token is invalid.")
if not hmac.compare_digest(flask.session['xsrf_token'], token):
raise XSRFError("XSRF token does not match server token.")
return True
def login():
return render_template(template,
nonce=get_setting('CSP_NONCE'),
client_id=client_id)
def get_client_id(self) -> str:
"""
Overrideable method to make customising the client_id
easier to do.
"""
return get_setting(self._CLIENT_ID_SETTING)
def get_template_folder(self) -> str:
"""
Overrideable method to make customising the template folder
easier to do.
"""
return get_setting(self._AUTH_TEMPLATE_FOLDER_SETTING)
import inspect
from importlib import import_module
from secure_scaffold.config import get_setting
try:
_DATABASE_SETTINGS = get_setting('DATABASE_SETTINGS')
except AttributeError:
raise AttributeError('DATABASE_SETTINGS setting not defined. '
'For the database system to work the '
'DATABASE_SETTINGS setting must be defined.')
_ENGINE_KEY = _DATABASE_SETTINGS.get('engine')
if not _ENGINE_KEY:
raise KeyError('DATABASE_SETTINGS improperly defined. '
'Requires an engine value.')
_ENGINE_MODULE = import_module(_DATABASE_SETTINGS['engine'])
_ENGINE_SETTINGS = _DATABASE_SETTINGS.get('settings')
if not _ENGINE_SETTINGS:
raise KeyError('DATABASE_SETTINGS improperly defined. '
'Requires a settings value.')
ENGINE = _ENGINE_MODULE.Engine(**_DATABASE_SETTINGS['settings'])
class NotUniqueError(Exception):
pass
