swift/swift/common/middleware/tempauth.py

497 lines
21 KiB
Python

# Copyright (c) 2011 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from time import time
from traceback import format_exc
from urllib import unquote
from uuid import uuid4
from hashlib import sha1
import hmac
import base64
from eventlet import Timeout
from swift.common.swob import Response, Request
from swift.common.swob import HTTPBadRequest, HTTPForbidden, HTTPNotFound, \
HTTPUnauthorized
from swift.common.middleware.acl import clean_acl, parse_acl, referrer_allowed
from swift.common.utils import cache_from_env, get_logger, \
split_path, config_true_value
class TempAuth(object):
"""
Test authentication and authorization system.
Add to your pipeline in proxy-server.conf, such as::
[pipeline:main]
pipeline = catch_errors cache tempauth proxy-server
Set account auto creation to true in proxy-server.conf::
[app:proxy-server]
account_autocreate = true
And add a tempauth filter section, such as::
[filter:tempauth]
use = egg:swift#tempauth
user_admin_admin = admin .admin .reseller_admin
user_test_tester = testing .admin
user_test2_tester2 = testing2 .admin
user_test_tester3 = testing3
# To allow accounts/users with underscores you can base64 encode them.
# Here is the account "under_score" and username "a_b" (note the lack
# of padding equal signs):
user64_dW5kZXJfc2NvcmU_YV9i = testing4
See the proxy-server.conf-sample for more information.
:param app: The next WSGI app in the pipeline
:param conf: The dict of configuration values
"""
def __init__(self, app, conf):
self.app = app
self.conf = conf
self.logger = get_logger(conf, log_route='tempauth')
self.log_headers = config_true_value(conf.get('log_headers', 'f'))
self.reseller_prefix = conf.get('reseller_prefix', 'AUTH').strip()
if self.reseller_prefix and self.reseller_prefix[-1] != '_':
self.reseller_prefix += '_'
self.logger.set_statsd_prefix('tempauth.%s' % (
self.reseller_prefix if self.reseller_prefix else 'NONE',))
self.auth_prefix = conf.get('auth_prefix', '/auth/')
if not self.auth_prefix or not self.auth_prefix.strip('/'):
self.logger.warning('Rewriting invalid auth prefix "%s" to '
'"/auth/" (Non-empty auth prefix path '
'is required)' % self.auth_prefix)
self.auth_prefix = '/auth/'
if self.auth_prefix[0] != '/':
self.auth_prefix = '/' + self.auth_prefix
if self.auth_prefix[-1] != '/':
self.auth_prefix += '/'
self.token_life = int(conf.get('token_life', 86400))
self.allow_overrides = config_true_value(
conf.get('allow_overrides', 't'))
self.storage_url_scheme = conf.get('storage_url_scheme', 'default')
self.users = {}
for conf_key in conf:
if conf_key.startswith('user_') or conf_key.startswith('user64_'):
account, username = conf_key.split('_', 1)[1].split('_')
if conf_key.startswith('user64_'):
# Because trailing equal signs would screw up config file
# parsing, we auto-pad with '=' chars.
account += '=' * (len(account) % 4)
account = base64.b64decode(account)
username += '=' * (len(username) % 4)
username = base64.b64decode(username)
values = conf[conf_key].split()
if not values:
raise ValueError('%s has no key set' % conf_key)
key = values.pop(0)
if values and ('://' in values[-1] or '$HOST' in values[-1]):
url = values.pop()
else:
url = '$HOST/v1/%s%s' % (self.reseller_prefix, account)
self.users[account + ':' + username] = {
'key': key, 'url': url, 'groups': values}
def __call__(self, env, start_response):
"""
Accepts a standard WSGI application call, authenticating the request
and installing callback hooks for authorization and ACL header
validation. For an authenticated request, REMOTE_USER will be set to a
comma separated list of the user's groups.
With a non-empty reseller prefix, acts as the definitive auth service
for just tokens and accounts that begin with that prefix, but will deny
requests outside this prefix if no other auth middleware overrides it.
With an empty reseller prefix, acts as the definitive auth service only
for tokens that validate to a non-empty set of groups. For all other
requests, acts as the fallback auth service when no other auth
middleware overrides it.
Alternatively, if the request matches the self.auth_prefix, the request
will be routed through the internal auth request handler (self.handle).
This is to handle granting tokens, etc.
"""
if self.allow_overrides and env.get('swift.authorize_override', False):
return self.app(env, start_response)
if env.get('PATH_INFO', '').startswith(self.auth_prefix):
return self.handle(env, start_response)
s3 = env.get('HTTP_AUTHORIZATION')
token = env.get('HTTP_X_AUTH_TOKEN', env.get('HTTP_X_STORAGE_TOKEN'))
if s3 or (token and token.startswith(self.reseller_prefix)):
# Note: Empty reseller_prefix will match all tokens.
groups = self.get_groups(env, token)
if groups:
user = groups and groups.split(',', 1)[0] or ''
trans_id = env.get('swift.trans_id')
self.logger.debug('User: %s uses token %s (trans_id %s)' %
(user, 's3' if s3 else token, trans_id))
env['REMOTE_USER'] = groups
env['swift.authorize'] = self.authorize
env['swift.clean_acl'] = clean_acl
if '.reseller_admin' in groups:
env['reseller_request'] = True
else:
# Unauthorized token
if self.reseller_prefix:
# Because I know I'm the definitive auth for this token, I
# can deny it outright.
self.logger.increment('unauthorized')
return HTTPUnauthorized()(env, start_response)
# Because I'm not certain if I'm the definitive auth for empty
# reseller_prefixed tokens, I won't overwrite swift.authorize.
elif 'swift.authorize' not in env:
env['swift.authorize'] = self.denied_response
else:
if self.reseller_prefix:
# With a non-empty reseller_prefix, I would like to be called
# back for anonymous access to accounts I know I'm the
# definitive auth for.
try:
version, rest = split_path(env.get('PATH_INFO', ''),
1, 2, True)
except ValueError:
version, rest = None, None
self.logger.increment('errors')
if rest and rest.startswith(self.reseller_prefix):
# Handle anonymous access to accounts I'm the definitive
# auth for.
env['swift.authorize'] = self.authorize
env['swift.clean_acl'] = clean_acl
# Not my token, not my account, I can't authorize this request,
# deny all is a good idea if not already set...
elif 'swift.authorize' not in env:
env['swift.authorize'] = self.denied_response
# Because I'm not certain if I'm the definitive auth for empty
# reseller_prefixed accounts, I won't overwrite swift.authorize.
elif 'swift.authorize' not in env:
env['swift.authorize'] = self.authorize
env['swift.clean_acl'] = clean_acl
return self.app(env, start_response)
def _get_user_groups(self, account, account_user, account_id):
"""
:param account: example: test
:param account_user: example: test:tester
"""
groups = [account, account_user]
groups.extend(self.users[account_user]['groups'])
if '.admin' in groups:
groups.remove('.admin')
groups.append(account_id)
groups = ','.join(groups)
return groups
def get_groups(self, env, token):
"""
Get groups for the given token.
:param env: The current WSGI environment dictionary.
:param token: Token to validate and return a group string for.
:returns: None if the token is invalid or a string containing a comma
separated list of groups the authenticated user is a member
of. The first group in the list is also considered a unique
identifier for that user.
"""
groups = None
memcache_client = cache_from_env(env)
if not memcache_client:
raise Exception('Memcache required')
memcache_token_key = '%s/token/%s' % (self.reseller_prefix, token)
cached_auth_data = memcache_client.get(memcache_token_key)
if cached_auth_data:
expires, groups = cached_auth_data
if expires < time():
groups = None
if env.get('HTTP_AUTHORIZATION'):
account_user, sign = \
env['HTTP_AUTHORIZATION'].split(' ')[1].rsplit(':', 1)
if account_user not in self.users:
return None
account, user = account_user.split(':', 1)
account_id = self.users[account_user]['url'].rsplit('/', 1)[-1]
path = env['PATH_INFO']
env['PATH_INFO'] = path.replace(account_user, account_id, 1)
msg = base64.urlsafe_b64decode(unquote(token))
key = self.users[account_user]['key']
s = base64.encodestring(hmac.new(key, msg, sha1).digest()).strip()
if s != sign:
return None
groups = self._get_user_groups(account, account_user, account_id)
return groups
def authorize(self, req):
"""
Returns None if the request is authorized to continue or a standard
WSGI response callable if not.
"""
try:
version, account, container, obj = req.split_path(1, 4, True)
except ValueError:
self.logger.increment('errors')
return HTTPNotFound(request=req)
if not account or not account.startswith(self.reseller_prefix):
self.logger.debug("Account name: %s doesn't start with "
"reseller_prefix: %s."
% (account, self.reseller_prefix))
return self.denied_response(req)
user_groups = (req.remote_user or '').split(',')
account_user = user_groups[1] if len(user_groups) > 1 else None
if '.reseller_admin' in user_groups and \
account != self.reseller_prefix and \
account[len(self.reseller_prefix)] != '.':
req.environ['swift_owner'] = True
self.logger.debug("User %s has reseller admin authorizing."
% account_user)
return None
if account in user_groups and \
(req.method not in ('DELETE', 'PUT') or container):
# If the user is admin for the account and is not trying to do an
# account DELETE or PUT...
req.environ['swift_owner'] = True
self.logger.debug("User %s has admin authorizing."
% account_user)
return None
if (req.environ.get('swift_sync_key')
and (req.environ['swift_sync_key'] ==
req.headers.get('x-container-sync-key', None))
and 'x-timestamp' in req.headers):
self.logger.debug("Allow request with container sync-key: %s."
% req.environ['swift_sync_key'])
return None
if req.method == 'OPTIONS':
#allow OPTIONS requests to proceed as normal
self.logger.debug("Allow OPTIONS request.")
return None
referrers, groups = parse_acl(getattr(req, 'acl', None))
if referrer_allowed(req.referer, referrers):
if obj or '.rlistings' in groups:
self.logger.debug("Allow authorizing %s via referer ACL."
% req.referer)
return None
for user_group in user_groups:
if user_group in groups:
self.logger.debug("User %s allowed in ACL: %s authorizing."
% (account_user, user_group))
return None
return self.denied_response(req)
def denied_response(self, req):
"""
Returns a standard WSGI response callable with the status of 403 or 401
depending on whether the REMOTE_USER is set or not.
"""
if req.remote_user:
self.logger.increment('forbidden')
return HTTPForbidden(request=req)
else:
self.logger.increment('unauthorized')
return HTTPUnauthorized(request=req)
def handle(self, env, start_response):
"""
WSGI entry point for auth requests (ones that match the
self.auth_prefix).
Wraps env in swob.Request object and passes it down.
:param env: WSGI environment dictionary
:param start_response: WSGI callable
"""
try:
req = Request(env)
if self.auth_prefix:
req.path_info_pop()
req.bytes_transferred = '-'
req.client_disconnect = False
if 'x-storage-token' in req.headers and \
'x-auth-token' not in req.headers:
req.headers['x-auth-token'] = req.headers['x-storage-token']
return self.handle_request(req)(env, start_response)
except (Exception, Timeout):
print "EXCEPTION IN handle: %s: %s" % (format_exc(), env)
self.logger.increment('errors')
start_response('500 Server Error',
[('Content-Type', 'text/plain')])
return ['Internal server error.\n']
def handle_request(self, req):
"""
Entry point for auth requests (ones that match the self.auth_prefix).
Should return a WSGI-style callable (such as swob.Response).
:param req: swob.Request object
"""
req.start_time = time()
handler = None
try:
version, account, user, _junk = req.split_path(1, 4, True)
except ValueError:
self.logger.increment('errors')
return HTTPNotFound(request=req)
if version in ('v1', 'v1.0', 'auth'):
if req.method == 'GET':
handler = self.handle_get_token
if not handler:
self.logger.increment('errors')
req.response = HTTPBadRequest(request=req)
else:
req.response = handler(req)
return req.response
def handle_get_token(self, req):
"""
Handles the various `request for token and service end point(s)` calls.
There are various formats to support the various auth servers in the
past. Examples::
GET <auth-prefix>/v1/<act>/auth
X-Auth-User: <act>:<usr> or X-Storage-User: <usr>
X-Auth-Key: <key> or X-Storage-Pass: <key>
GET <auth-prefix>/auth
X-Auth-User: <act>:<usr> or X-Storage-User: <act>:<usr>
X-Auth-Key: <key> or X-Storage-Pass: <key>
GET <auth-prefix>/v1.0
X-Auth-User: <act>:<usr> or X-Storage-User: <act>:<usr>
X-Auth-Key: <key> or X-Storage-Pass: <key>
On successful authentication, the response will have X-Auth-Token and
X-Storage-Token set to the token to use with Swift and X-Storage-URL
set to the URL to the default Swift cluster to use.
:param req: The swob.Request to process.
:returns: swob.Response, 2xx on success with data set as explained
above.
"""
# Validate the request info
try:
pathsegs = split_path(req.path_info, 1, 3, True)
except ValueError:
self.logger.increment('errors')
return HTTPNotFound(request=req)
if pathsegs[0] == 'v1' and pathsegs[2] == 'auth':
account = pathsegs[1]
user = req.headers.get('x-storage-user')
if not user:
user = req.headers.get('x-auth-user')
if not user or ':' not in user:
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
account2, user = user.split(':', 1)
if account != account2:
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
key = req.headers.get('x-storage-pass')
if not key:
key = req.headers.get('x-auth-key')
elif pathsegs[0] in ('auth', 'v1.0'):
user = req.headers.get('x-auth-user')
if not user:
user = req.headers.get('x-storage-user')
if not user or ':' not in user:
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
account, user = user.split(':', 1)
key = req.headers.get('x-auth-key')
if not key:
key = req.headers.get('x-storage-pass')
else:
return HTTPBadRequest(request=req)
if not all((account, user, key)):
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
# Authenticate user
account_user = account + ':' + user
if account_user not in self.users:
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
if self.users[account_user]['key'] != key:
self.logger.increment('token_denied')
return HTTPUnauthorized(request=req)
account_id = self.users[account_user]['url'].rsplit('/', 1)[-1]
# Get memcache client
memcache_client = cache_from_env(req.environ)
if not memcache_client:
raise Exception('Memcache required')
# See if a token already exists and hasn't expired
token = None
memcache_user_key = '%s/user/%s' % (self.reseller_prefix, account_user)
candidate_token = memcache_client.get(memcache_user_key)
if candidate_token:
memcache_token_key = \
'%s/token/%s' % (self.reseller_prefix, candidate_token)
cached_auth_data = memcache_client.get(memcache_token_key)
if cached_auth_data:
expires, old_groups = cached_auth_data
old_groups = old_groups.split(',')
new_groups = self._get_user_groups(account, account_user,
account_id)
if expires > time() and \
set(old_groups) == set(new_groups.split(',')):
token = candidate_token
# Create a new token if one didn't exist
if not token:
# Generate new token
token = '%stk%s' % (self.reseller_prefix, uuid4().hex)
expires = time() + self.token_life
groups = self._get_user_groups(account, account_user, account_id)
# Save token
memcache_token_key = '%s/token/%s' % (self.reseller_prefix, token)
memcache_client.set(memcache_token_key, (expires, groups),
time=float(expires - time()))
# Record the token with the user info for future use.
memcache_user_key = \
'%s/user/%s' % (self.reseller_prefix, account_user)
memcache_client.set(memcache_user_key, token,
time=float(expires - time()))
resp = Response(request=req, headers={
'x-auth-token': token, 'x-storage-token': token})
url = self.users[account_user]['url'].replace('$HOST', resp.host_url)
if self.storage_url_scheme != 'default':
url = self.storage_url_scheme + ':' + url.split(':', 1)[1]
resp.headers['x-storage-url'] = url
return resp
def filter_factory(global_conf, **local_conf):
"""Returns a WSGI filter app for use with paste.deploy."""
conf = global_conf.copy()
conf.update(local_conf)
def auth_filter(app):
return TempAuth(app, conf)
return auth_filter