Update LICENSE, README.md, setup.py, quart_csrf/csrf.py, quart_csrf/__init__.py files
This commit is contained in:
Wagner Corrales
1
quart_csrf/__init__.py
Normal file
1
quart_csrf/__init__.py
Normal file
@@ -0,0 +1 @@
|
||||
from .csrf import generate_csrf, validate_csrf, CSRFProtect
|
||||
253
quart_csrf/csrf.py
Normal file
253
quart_csrf/csrf.py
Normal file
@@ -0,0 +1,253 @@
|
||||
import hashlib
|
||||
import logging
|
||||
import os
|
||||
from urllib.parse import urlparse
|
||||
|
||||
from itsdangerous import BadData, SignatureExpired, URLSafeTimedSerializer
|
||||
from quart import current_app, g, request, session
|
||||
from werkzeug.exceptions import BadRequest
|
||||
from werkzeug.security import safe_str_cmp
|
||||
from wtforms import ValidationError
|
||||
|
||||
|
||||
__all__ = ('generate_csrf', 'validate_csrf', 'CSRFProtect')
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
|
||||
def generate_csrf(secret_key=None, token_key=None):
|
||||
"""Generate a CSRF token. The token is cached for a request, so multiple
|
||||
calls to this function will generate the same token.
|
||||
|
||||
During testing, it might be useful to access the signed token in
|
||||
``g.csrf_token`` and the raw token in ``session['csrf_token']``.
|
||||
|
||||
:param secret_key: Used to securely sign the token. Default is
|
||||
``QUART_CSRF_SECRET_KEY`` or ``SECRET_KEY``.
|
||||
:param token_key: Key where token is stored in session for comparison.
|
||||
Default is ``QUART_CSRF_FIELD_NAME`` or ``'csrf_token'``.
|
||||
"""
|
||||
|
||||
secret_key = _get_config(
|
||||
secret_key, 'QUART_CSRF_SECRET_KEY', current_app.secret_key,
|
||||
message='A secret key is required to use CSRF.'
|
||||
)
|
||||
field_name = _get_config(
|
||||
token_key, 'QUART_CSRF_FIELD_NAME', 'csrf_token',
|
||||
message='A field name is required to use CSRF.'
|
||||
)
|
||||
|
||||
if field_name not in g:
|
||||
s = URLSafeTimedSerializer(secret_key, salt='quart-csrf-token')
|
||||
|
||||
if field_name not in session:
|
||||
session[field_name] = hashlib.sha1(os.urandom(64)).hexdigest()
|
||||
|
||||
try:
|
||||
token = s.dumps(session[field_name])
|
||||
except TypeError:
|
||||
session[field_name] = hashlib.sha1(os.urandom(64)).hexdigest()
|
||||
token = s.dumps(session[field_name])
|
||||
|
||||
setattr(g, field_name, token)
|
||||
|
||||
return g.get(field_name)
|
||||
|
||||
|
||||
def validate_csrf(data, secret_key=None, time_limit=None, token_key=None):
|
||||
"""Check if the given data is a valid CSRF token. This compares the given
|
||||
signed token to the one stored in the session.
|
||||
|
||||
:param data: The signed CSRF token to be checked.
|
||||
:param secret_key: Used to securely sign the token. Default is
|
||||
``QUART_CSRF_SECRET_KEY`` or ``SECRET_KEY``.
|
||||
:param time_limit: Number of seconds that the token is valid. Default is
|
||||
``QUART_CSRF_TIME_LIMIT`` or 3600 seconds (60 minutes).
|
||||
:param token_key: Key where token is stored in session for comparison.
|
||||
Default is ``QUART_CSRF_FIELD_NAME`` or ``'csrf_token'``.
|
||||
|
||||
:raises ValidationError: Contains the reason that validation failed.
|
||||
|
||||
.. versionchanged:: 0.14
|
||||
Raises ``ValidationError`` with a specific error message rather than
|
||||
returning ``True`` or ``False``.
|
||||
"""
|
||||
|
||||
secret_key = _get_config(
|
||||
secret_key, 'QUART_CSRF_SECRET_KEY', current_app.secret_key,
|
||||
message='A secret key is required to use CSRF.'
|
||||
)
|
||||
field_name = _get_config(
|
||||
token_key, 'QUART_CSRF_FIELD_NAME', 'csrf_token',
|
||||
message='A field name is required to use CSRF.'
|
||||
)
|
||||
time_limit = _get_config(
|
||||
time_limit, 'QUART_CSRF_TIME_LIMIT', 3600, required=False
|
||||
)
|
||||
|
||||
if not data:
|
||||
raise ValidationError('The CSRF token is missing.')
|
||||
|
||||
if field_name not in session:
|
||||
raise ValidationError('The CSRF session token is missing.')
|
||||
|
||||
s = URLSafeTimedSerializer(secret_key, salt='quart-csrf-token')
|
||||
|
||||
try:
|
||||
token = s.loads(data, max_age=time_limit)
|
||||
except SignatureExpired:
|
||||
raise ValidationError('The CSRF token has expired.')
|
||||
except BadData:
|
||||
raise ValidationError('The CSRF token is invalid.')
|
||||
|
||||
if not safe_str_cmp(session[field_name], token):
|
||||
raise ValidationError('The CSRF tokens do not match.')
|
||||
|
||||
|
||||
def _get_config(
|
||||
value, config_name, default=None,
|
||||
required=True, message='CSRF is not configured.'
|
||||
):
|
||||
"""Find config value based on provided value, Flask config, and default
|
||||
value.
|
||||
|
||||
:param value: already provided config value
|
||||
:param config_name: Flask ``config`` key
|
||||
:param default: default value if not provided or configured
|
||||
:param required: whether the value must not be ``None``
|
||||
:param message: error message if required config is not found
|
||||
:raises KeyError: if required config is not found
|
||||
"""
|
||||
|
||||
if value is None:
|
||||
value = current_app.config.get(config_name, default)
|
||||
|
||||
if required and value is None:
|
||||
raise RuntimeError(message)
|
||||
|
||||
return value
|
||||
|
||||
|
||||
class CSRFProtect:
|
||||
"""Enable CSRF protection globally for a Flask app.
|
||||
|
||||
::
|
||||
|
||||
app = Flask(__name__)
|
||||
csrf = CSRFProtect(app)
|
||||
|
||||
Checks the ``csrf_token`` field sent with forms, or the ``X-CSRFToken``
|
||||
header sent with JavaScript requests. Render the token in templates using
|
||||
``{{ csrf_token() }}``.
|
||||
|
||||
See the :ref:`csrf` documentation.
|
||||
"""
|
||||
|
||||
def __init__(self, app=None):
|
||||
if app:
|
||||
self.init_app(app)
|
||||
|
||||
def init_app(self, app):
|
||||
app.extensions['csrf'] = self
|
||||
|
||||
app.config.setdefault('QUART_CSRF_ENABLED', True)
|
||||
app.config.setdefault('QUART_CSRF_CHECK_DEFAULT', True)
|
||||
app.config['QUART_CSRF_METHODS'] = set(app.config.get(
|
||||
'QUART_CSRF_METHODS', ['POST', 'PUT', 'PATCH', 'DELETE']
|
||||
))
|
||||
app.config.setdefault('QUART_CSRF_FIELD_NAME', 'csrf_token')
|
||||
app.config.setdefault(
|
||||
'QUART_CSRF_HEADERS', ['X-CSRFToken', 'X-CSRF-Token']
|
||||
)
|
||||
app.config.setdefault('QUART_CSRF_TIME_LIMIT', 3600)
|
||||
app.config.setdefault('QUART_CSRF_SSL_STRICT', True)
|
||||
|
||||
app.jinja_env.globals['csrf_token'] = generate_csrf
|
||||
app.context_processor(lambda: {'csrf_token': generate_csrf})
|
||||
|
||||
@app.before_request
|
||||
async def csrf_protect():
|
||||
if not app.config['QUART_CSRF_ENABLED']:
|
||||
return
|
||||
|
||||
if not app.config['QUART_CSRF_CHECK_DEFAULT']:
|
||||
return
|
||||
|
||||
if request.method not in app.config['QUART_CSRF_METHODS']:
|
||||
return
|
||||
|
||||
if not request.endpoint:
|
||||
return
|
||||
|
||||
await self.protect()
|
||||
|
||||
async def _get_csrf_token(self):
|
||||
# find the token in the form data
|
||||
form = await request.form
|
||||
field_name = current_app.config['QUART_CSRF_FIELD_NAME']
|
||||
base_token = form.get(field_name)
|
||||
|
||||
if base_token:
|
||||
return base_token
|
||||
|
||||
# if the form has a prefix, the name will be {prefix}-csrf_token
|
||||
for key in form:
|
||||
if key.endswith(field_name):
|
||||
csrf_token = form[key]
|
||||
|
||||
if csrf_token:
|
||||
return csrf_token
|
||||
|
||||
# find the token in the headers
|
||||
for header_name in current_app.config['QUART_CSRF_HEADERS']:
|
||||
csrf_token = request.headers.get(header_name)
|
||||
|
||||
if csrf_token:
|
||||
return csrf_token
|
||||
|
||||
return None
|
||||
|
||||
async def protect(self):
|
||||
if request.method not in current_app.config['QUART_CSRF_METHODS']:
|
||||
return
|
||||
|
||||
try:
|
||||
validate_csrf(await self._get_csrf_token())
|
||||
except ValidationError as e:
|
||||
logger.info(e.args[0])
|
||||
self._error_response(e.args[0])
|
||||
|
||||
if request.is_secure and current_app.config['QUART_CSRF_SSL_STRICT']:
|
||||
if not request.referrer:
|
||||
self._error_response('The referrer header is missing.')
|
||||
|
||||
good_referrer = f'https://{request.host}/'
|
||||
|
||||
if not same_origin(request.referrer, good_referrer):
|
||||
self._error_response('The referrer does not match the host.')
|
||||
|
||||
g.csrf_valid = True # mark this request as CSRF valid
|
||||
|
||||
def _error_response(self, reason):
|
||||
raise CSRFError(reason)
|
||||
|
||||
|
||||
class CSRFError(BadRequest):
|
||||
"""Raise if the client sends invalid CSRF data with the request.
|
||||
|
||||
Generates a 400 Bad Request response with the failure reason by default.
|
||||
Customize the response by registering a handler with
|
||||
:meth:`flask.Flask.errorhandler`.
|
||||
"""
|
||||
|
||||
description = 'CSRF validation failed.'
|
||||
|
||||
|
||||
def same_origin(current_uri, compare_uri):
|
||||
current = urlparse(current_uri)
|
||||
compare = urlparse(compare_uri)
|
||||
|
||||
return (
|
||||
current.scheme == compare.scheme
|
||||
and current.hostname == compare.hostname
|
||||
and current.port == compare.port
|
||||
)
|
||||
Reference in New Issue
Block a user