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csrf.py
161 lines
| 5.2 KiB
| text/x-python
|
PythonLexer
r1 | # -*- coding: utf-8 -*- | |||
r1271 | # Copyright (C) 2010-2017 RhodeCode GmbH | |||
r1 | # | |||
# This program is free software: you can redistribute it and/or modify | ||||
# it under the terms of the GNU Affero General Public License, version 3 | ||||
# (only), as published by the Free Software Foundation. | ||||
# | ||||
# This program is distributed in the hope that it will be useful, | ||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of | ||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||||
# GNU General Public License for more details. | ||||
# | ||||
# You should have received a copy of the GNU Affero General Public License | ||||
# along with this program. If not, see <http://www.gnu.org/licenses/>. | ||||
# | ||||
# This program is dual-licensed. If you wish to learn more about the | ||||
# RhodeCode Enterprise Edition, including its added features, Support services, | ||||
# and proprietary license terms, please see https://rhodecode.com/licenses/ | ||||
import logging | ||||
import textwrap | ||||
import routes.middleware | ||||
import urlobject | ||||
import webob | ||||
import webob.exc | ||||
import rhodecode.lib.auth | ||||
log = logging.getLogger(__name__) | ||||
class CSRFDetector(object): | ||||
""" | ||||
Middleware for preventing CSRF. | ||||
It checks that all requests are either GET or POST. | ||||
For POST requests, it logs the requests that do not have a CSRF token. | ||||
Eventually it will raise an error. | ||||
It special cases some endpoints as they do not really require a token. | ||||
Note: this middleware is only intended for testing. | ||||
""" | ||||
_PUT_DELETE_MESSAGE = textwrap.dedent(''' | ||||
Do not call in tests app.delete or app.put, use instead | ||||
app.post(..., params={'_method': 'delete'}. | ||||
The reason is twofold. The first is because that's how the browser is | ||||
calling rhodecode and the second is because it allow us to detect | ||||
potential CSRF.''').strip() | ||||
_PATHS_WITHOUT_TOKEN = frozenset(( | ||||
# The password is the token. | ||||
'/_admin/login', | ||||
# Captcha may be enabled. | ||||
'/_admin/password_reset', | ||||
# Captcha may be enabled. | ||||
'/_admin/password_reset_confirmation', | ||||
# Captcha may be enabled. | ||||
'/_admin/register', | ||||
# No change in state with this controller. | ||||
'/error/document', | ||||
)) | ||||
r1891 | _SKIP_PATTERN = frozenset(( | |||
'/_admin/gists/', | ||||
)) | ||||
r1 | def __init__(self, app): | |||
self._app = app | ||||
def __call__(self, environ, start_response): | ||||
if environ['REQUEST_METHOD'].upper() not in ('GET', 'POST'): | ||||
raise Exception(self._PUT_DELETE_MESSAGE) | ||||
r1891 | token_expected = environ['PATH_INFO'] not in self._PATHS_WITHOUT_TOKEN | |||
allowed = True | ||||
for pattern in self._SKIP_PATTERN: | ||||
if environ['PATH_INFO'].startswith(pattern): | ||||
allowed = False | ||||
break | ||||
r1 | ||||
if (environ['REQUEST_METHOD'] == 'POST' and | ||||
r1891 | token_expected and allowed and | |||
r1 | routes.middleware.is_form_post(environ)): | |||
body = environ['wsgi.input'] | ||||
if body.seekable(): | ||||
pos = body.tell() | ||||
content = body.read() | ||||
body.seek(pos) | ||||
elif hasattr(body, 'peek'): | ||||
content = body.peek() | ||||
else: | ||||
raise Exception("Cannot check if the request has a CSRF token") | ||||
if rhodecode.lib.auth.csrf_token_key not in content: | ||||
raise Exception( | ||||
'%s to %s does not have a csrf_token %r' % | ||||
(environ['REQUEST_METHOD'], environ['PATH_INFO'], content)) | ||||
return self._app(environ, start_response) | ||||
def _get_scheme_host_port(url): | ||||
url = urlobject.URLObject(url) | ||||
if '://' not in url: | ||||
return None, url, None | ||||
scheme = url.scheme or 'http' | ||||
port = url.port | ||||
if not port: | ||||
if scheme == 'http': | ||||
port = 80 | ||||
elif scheme == 'https': | ||||
port = 443 | ||||
host = url.netloc.without_port() | ||||
return scheme, host, port | ||||
def _equivalent_urls(url1, url2): | ||||
"""Check if both urls are equivalent.""" | ||||
return _get_scheme_host_port(url1) == _get_scheme_host_port(url2) | ||||
class OriginChecker(object): | ||||
""" | ||||
Check whether the request has a valid Origin header. | ||||
See https://wiki.mozilla.org/Security/Origin for details. | ||||
""" | ||||
def __init__(self, app, expected_origin, skip_urls=None): | ||||
""" | ||||
:param expected_origin: the value we expect to see for the Origin | ||||
header. | ||||
:param skip_urls: list of urls for which we do not need to check the | ||||
Origin header. | ||||
""" | ||||
self._app = app | ||||
self._expected_origin = expected_origin | ||||
self._skip_urls = frozenset(skip_urls or []) | ||||
def __call__(self, environ, start_response): | ||||
origin_header = environ.get('HTTP_ORIGIN', '') | ||||
origin = origin_header.split(' ', 1)[0] | ||||
if origin == 'null': | ||||
origin = None | ||||
if (environ['PATH_INFO'] not in self._skip_urls and origin and | ||||
not _equivalent_urls(origin, self._expected_origin)): | ||||
log.warn( | ||||
'Invalid Origin header detected: got %s, expected %s', | ||||
origin_header, self._expected_origin) | ||||
return webob.exc.HTTPForbidden('Origin header mismatch')( | ||||
environ, start_response) | ||||
else: | ||||
return self._app(environ, start_response) | ||||