diff --git a/CHANGES b/CHANGES index ddab541fb2..a6eceb876b 100644 --- a/CHANGES +++ b/CHANGES @@ -34,6 +34,12 @@ Major release, unreleased type is invalid. (`#2256`_) - Add ``routes`` CLI command to output routes registered on the application. (`#2259`_) +- Show warning when session cookie domain is a bare hostname or an IP + address, as these may not behave properly in some browsers, such as Chrome. + (`#2282`_) +- Allow IP address as exact session cookie domain. (`#2282`_) +- ``SESSION_COOKIE_DOMAIN`` is set if it is detected through ``SERVER_NAME``. + (`#2282`_) .. _#1489: https://github.com/pallets/flask/pull/1489 .. _#1898: https://github.com/pallets/flask/pull/1898 @@ -43,6 +49,7 @@ Major release, unreleased .. _#2254: https://github.com/pallets/flask/pull/2254 .. _#2256: https://github.com/pallets/flask/pull/2256 .. _#2259: https://github.com/pallets/flask/pull/2259 +.. _#2282: https://github.com/pallets/flask/pull/2282 Version 0.12.1 -------------- diff --git a/flask/helpers.py b/flask/helpers.py index 828f584022..51c3b064a8 100644 --- a/flask/helpers.py +++ b/flask/helpers.py @@ -10,6 +10,7 @@ """ import os +import socket import sys import pkgutil import posixpath @@ -976,3 +977,24 @@ def total_seconds(td): :rtype: int """ return td.days * 60 * 60 * 24 + td.seconds + + +def is_ip(value): + """Determine if the given string is an IP address. + + :param value: value to check + :type value: str + + :return: True if string is an IP address + :rtype: bool + """ + + for family in (socket.AF_INET, socket.AF_INET6): + try: + socket.inet_pton(family, value) + except socket.error: + pass + else: + return True + + return False diff --git a/flask/sessions.py b/flask/sessions.py index 525ff246ec..9fef6a9d76 100644 --- a/flask/sessions.py +++ b/flask/sessions.py @@ -11,13 +11,14 @@ import uuid import hashlib +import warnings from base64 import b64encode, b64decode from datetime import datetime from werkzeug.http import http_date, parse_date from werkzeug.datastructures import CallbackDict from . import Markup, json from ._compat import iteritems, text_type -from .helpers import total_seconds +from .helpers import total_seconds, is_ip from itsdangerous import URLSafeTimedSerializer, BadSignature @@ -200,30 +201,62 @@ def is_null_session(self, obj): return isinstance(obj, self.null_session_class) def get_cookie_domain(self, app): - """Helpful helper method that returns the cookie domain that should - be used for the session cookie if session cookies are used. + """Returns the domain that should be set for the session cookie. + + Uses ``SESSION_COOKIE_DOMAIN`` if it is configured, otherwise + falls back to detecting the domain based on ``SERVER_NAME``. + + Once detected (or if not set at all), ``SESSION_COOKIE_DOMAIN`` is + updated to avoid re-running the logic. """ - if app.config['SESSION_COOKIE_DOMAIN'] is not None: - return app.config['SESSION_COOKIE_DOMAIN'] - if app.config['SERVER_NAME'] is not None: - # chop off the port which is usually not supported by browsers - rv = '.' + app.config['SERVER_NAME'].rsplit(':', 1)[0] - - # Google chrome does not like cookies set to .localhost, so - # we just go with no domain then. Flask documents anyways that - # cross domain cookies need a fully qualified domain name - if rv == '.localhost': - rv = None - - # If we infer the cookie domain from the server name we need - # to check if we are in a subpath. In that case we can't - # set a cross domain cookie. - if rv is not None: - path = self.get_cookie_path(app) - if path != '/': - rv = rv.lstrip('.') - - return rv + + rv = app.config['SESSION_COOKIE_DOMAIN'] + + # set explicitly, or cached from SERVER_NAME detection + # if False, return None + if rv is not None: + return rv if rv else None + + rv = app.config['SERVER_NAME'] + + # server name not set, cache False to return none next time + if not rv: + app.config['SESSION_COOKIE_DOMAIN'] = False + return None + + # chop off the port which is usually not supported by browsers + # remove any leading '.' since we'll add that later + rv = rv.rsplit(':', 1)[0].lstrip('.') + + if '.' not in rv: + # Chrome doesn't allow names without a '.' + # this should only come up with localhost + # hack around this by not setting the name, and show a warning + warnings.warn( + '"{rv}" is not a valid cookie domain, it must contain a ".".' + ' Add an entry to your hosts file, for example' + ' "{rv}.localdomain", and use that instead.'.format(rv=rv) + ) + app.config['SESSION_COOKIE_DOMAIN'] = False + return None + + ip = is_ip(rv) + + if ip: + warnings.warn( + 'The session cookie domain is an IP address. This may not work' + ' as intended in some browsers. Add an entry to your hosts' + ' file, for example "localhost.localdomain", and use that' + ' instead.' + ) + + # if this is not an ip and app is mounted at the root, allow subdomain + # matching by adding a '.' prefix + if self.get_cookie_path(app) == '/' and not ip: + rv = '.' + rv + + app.config['SESSION_COOKIE_DOMAIN'] = rv + return rv def get_cookie_path(self, app): """Returns the path for which the cookie should be valid. The diff --git a/tests/test_basic.py b/tests/test_basic.py index 163b83cfa3..80091bd6d4 100644 --- a/tests/test_basic.py +++ b/tests/test_basic.py @@ -351,6 +351,42 @@ def index(): assert 'httponly' not in cookie +def test_session_localhost_warning(recwarn): + app = flask.Flask(__name__) + app.config.update( + SECRET_KEY='testing', + SERVER_NAME='localhost:5000', + ) + + @app.route('/') + def index(): + flask.session['testing'] = 42 + return 'testing' + + rv = app.test_client().get('/', 'http://localhost:5000/') + assert 'domain' not in rv.headers['set-cookie'].lower() + w = recwarn.pop(UserWarning) + assert '"localhost" is not a valid cookie domain' in str(w.message) + + +def test_session_ip_warning(recwarn): + app = flask.Flask(__name__) + app.config.update( + SECRET_KEY='testing', + SERVER_NAME='127.0.0.1:5000', + ) + + @app.route('/') + def index(): + flask.session['testing'] = 42 + return 'testing' + + rv = app.test_client().get('/', 'http://127.0.0.1:5000/') + assert 'domain=127.0.0.1' in rv.headers['set-cookie'].lower() + w = recwarn.pop(UserWarning) + assert 'cookie domain is an IP' in str(w.message) + + def test_missing_session(): app = flask.Flask(__name__)