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Diffstat (limited to 'gluster/swift/common/middleware/swiftkerbauth/kerbauth.py')
-rw-r--r-- | gluster/swift/common/middleware/swiftkerbauth/kerbauth.py | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/gluster/swift/common/middleware/swiftkerbauth/kerbauth.py b/gluster/swift/common/middleware/swiftkerbauth/kerbauth.py new file mode 100644 index 0000000..a1ba091 --- /dev/null +++ b/gluster/swift/common/middleware/swiftkerbauth/kerbauth.py @@ -0,0 +1,328 @@ +# Copyright (c) 2013 Red Hat, Inc. +# +# 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 eventlet import Timeout + +from swift.common.swob import Request +from swift.common.swob import HTTPBadRequest, HTTPForbidden, HTTPNotFound, \ + HTTPSeeOther + +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 KerbAuth(object): + """ + Test authentication and authorization system. + + Add to your pipeline in proxy-server.conf, such as:: + + [pipeline:main] + pipeline = catch_errors cache kerbauth proxy-server + + Set account auto creation to true in proxy-server.conf:: + + [app:proxy-server] + account_autocreate = true + + And add a kerbauth filter section, such as:: + + [filter:kerbauth] + use = egg:swiftkerbauth#kerbauth + + 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='kerbauth') + 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('kerbauth.%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.ext_authentication_url = conf.get('ext_authentication_url') + if not self.ext_authentication_url: + raise RuntimeError("Missing filter parameter ext_authentication_" + "url in /etc/swift/proxy-server.conf") + + 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. + + 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) + token = env.get('HTTP_X_AUTH_TOKEN', env.get('HTTP_X_STORAGE_TOKEN')) + if token and token.startswith(self.reseller_prefix): + 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, 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: + # Invalid token (may be expired) + return HTTPSeeOther( + location=self.ext_authentication_url)(env, start_response) + else: + # 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') + # Not my token, not my account, I can't authorize this request, + # deny all is a good idea if not already set... + if 'swift.authorize' not in env: + env['swift.authorize'] = self.denied_response + + return self.app(env, start_response) + + 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 + + return groups + + def authorize(self, req): + """ + Returns None if the request is authorized to continue or a standard + WSGI response callable if not. + + Assumes that user groups are all lower case, which is true when Red Hat + Enterprise Linux Identity Management is used. + """ + 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 the user is in the reseller_admin group for our prefix, he gets + # full access to all accounts we manage. For the default reseller + # prefix, the group name is auth_reseller_admin. + admin_group = ("%sreseller_admin" % self.reseller_prefix).lower() + if admin_group in user_groups and \ + account != self.reseller_prefix and \ + account[len(self.reseller_prefix)] != '.': + req.environ['swift_owner'] = True + return None + + # The "account" is part of the request URL, and already contains the + # reseller prefix, like in "/v1/AUTH_vol1/pictures/pic1.png". + if account.lower() 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: + return HTTPSeeOther(location=self.ext_authentication_url) + + 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 webob.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 + GET <auth-prefix>/auth + GET <auth-prefix>/v1.0 + + All formats require GSS (Kerberos) authentication. + + On successful authentication, the response will have X-Auth-Token + set to the token to use with Swift. + + :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 not ((pathsegs[0] == 'v1' and pathsegs[2] == 'auth') + or pathsegs[0] in ('auth', 'v1.0')): + return HTTPBadRequest(request=req) + + return HTTPSeeOther(location=self.ext_authentication_url) + + +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 KerbAuth(app, conf) + return auth_filter |