262 lines
10 KiB
Python
262 lines
10 KiB
Python
# Copyright 2012 OpenStack Foundation
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# Copyright 2011,2012 Akira YOSHIYAMA <akirayoshiyama@gmail.com>
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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# This source code is based ./auth_token.py and ./ec2_token.py.
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# See them for their copyright.
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"""
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S3 TOKEN MIDDLEWARE
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This WSGI component:
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* Get a request from the swift3 middleware with an S3 Authorization
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access key.
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* Validate s3 token in Keystone.
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* Transform the account name to AUTH_%(tenant_name).
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"""
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import logging
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import urllib
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import webob
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import requests
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from keystoneclient.openstack.common import jsonutils
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PROTOCOL_NAME = 'S3 Token Authentication'
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# TODO(kun): remove it after oslo merge this.
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def split_path(path, minsegs=1, maxsegs=None, rest_with_last=False):
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"""Validate and split the given HTTP request path.
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**Examples**::
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['a'] = split_path('/a')
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['a', None] = split_path('/a', 1, 2)
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['a', 'c'] = split_path('/a/c', 1, 2)
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['a', 'c', 'o/r'] = split_path('/a/c/o/r', 1, 3, True)
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:param path: HTTP Request path to be split
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:param minsegs: Minimum number of segments to be extracted
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:param maxsegs: Maximum number of segments to be extracted
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:param rest_with_last: If True, trailing data will be returned as part
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of last segment. If False, and there is
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trailing data, raises ValueError.
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:returns: list of segments with a length of maxsegs (non-existant
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segments will return as None)
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:raises: ValueError if given an invalid path
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"""
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if not maxsegs:
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maxsegs = minsegs
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if minsegs > maxsegs:
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raise ValueError('minsegs > maxsegs: %d > %d' % (minsegs, maxsegs))
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if rest_with_last:
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segs = path.split('/', maxsegs)
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minsegs += 1
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maxsegs += 1
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count = len(segs)
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if (segs[0] or count < minsegs or count > maxsegs or
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'' in segs[1:minsegs]):
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raise ValueError('Invalid path: %s' % urllib.quote(path))
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else:
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minsegs += 1
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maxsegs += 1
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segs = path.split('/', maxsegs)
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count = len(segs)
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if (segs[0] or count < minsegs or count > maxsegs + 1 or
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'' in segs[1:minsegs] or
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(count == maxsegs + 1 and segs[maxsegs])):
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raise ValueError('Invalid path: %s' % urllib.quote(path))
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segs = segs[1:maxsegs]
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segs.extend([None] * (maxsegs - 1 - len(segs)))
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return segs
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class ServiceError(Exception):
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pass
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class S3Token(object):
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"""Auth Middleware that handles S3 authenticating client calls."""
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def __init__(self, app, conf):
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"""Common initialization code."""
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self.app = app
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self.logger = logging.getLogger(conf.get('log_name', __name__))
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self.logger.debug('Starting the %s component' % PROTOCOL_NAME)
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self.reseller_prefix = conf.get('reseller_prefix', 'AUTH_')
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# where to find the auth service (we use this to validate tokens)
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auth_host = conf.get('auth_host')
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auth_port = int(conf.get('auth_port', 35357))
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auth_protocol = conf.get('auth_protocol', 'https')
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self.request_uri = '%s://%s:%s' % (auth_protocol, auth_host, auth_port)
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# SSL
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insecure = conf.get('insecure', False)
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cert_file = conf.get('certfile')
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key_file = conf.get('keyfile')
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if insecure:
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self.verify = False
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elif cert_file and key_file:
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self.verify = (cert_file, key_file)
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elif cert_file:
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self.verify = cert_file
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else:
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self.verify = None
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def deny_request(self, code):
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error_table = {
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'AccessDenied': (401, 'Access denied'),
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'InvalidURI': (400, 'Could not parse the specified URI'),
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}
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resp = webob.Response(content_type='text/xml')
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resp.status = error_table[code][0]
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resp.body = error_table[code][1]
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resp.body = ('<?xml version="1.0" encoding="UTF-8"?>\r\n'
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'<Error>\r\n <Code>%s</Code>\r\n '
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'<Message>%s</Message>\r\n</Error>\r\n' %
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(code, error_table[code][1]))
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return resp
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def _json_request(self, creds_json):
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headers = {'Content-Type': 'application/json'}
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try:
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response = requests.post('%s/v2.0/s3tokens' % self.request_uri,
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headers=headers, data=creds_json,
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verify=self.verify)
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except requests.exceptions.RequestException as e:
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self.logger.info('HTTP connection exception: %s' % e)
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resp = self.deny_request('InvalidURI')
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raise ServiceError(resp)
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if response.status_code < 200 or response.status_code >= 300:
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self.logger.debug('Keystone reply error: status=%s reason=%s' %
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(response.status_code, response.reason))
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resp = self.deny_request('AccessDenied')
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raise ServiceError(resp)
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return response
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def __call__(self, environ, start_response):
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"""Handle incoming request. authenticate and send downstream."""
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req = webob.Request(environ)
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self.logger.debug('Calling S3Token middleware.')
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try:
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parts = split_path(req.path, 1, 4, True)
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version, account, container, obj = parts
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except ValueError:
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msg = 'Not a path query, skipping.'
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self.logger.debug(msg)
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return self.app(environ, start_response)
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# Read request signature and access id.
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if 'Authorization' not in req.headers:
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msg = 'No Authorization header. skipping.'
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self.logger.debug(msg)
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return self.app(environ, start_response)
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token = req.headers.get('X-Auth-Token',
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req.headers.get('X-Storage-Token'))
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if not token:
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msg = 'You did not specify a auth or a storage token. skipping.'
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self.logger.debug(msg)
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return self.app(environ, start_response)
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auth_header = req.headers['Authorization']
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try:
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access, signature = auth_header.split(' ')[-1].rsplit(':', 1)
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except ValueError:
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msg = 'You have an invalid Authorization header: %s'
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self.logger.debug(msg % (auth_header))
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return self.deny_request('InvalidURI')(environ, start_response)
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# NOTE(chmou): This is to handle the special case with nova
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# when we have the option s3_affix_tenant. We will force it to
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# connect to another account than the one
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# authenticated. Before people start getting worried about
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# security, I should point that we are connecting with
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# username/token specified by the user but instead of
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# connecting to its own account we will force it to go to an
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# another account. In a normal scenario if that user don't
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# have the reseller right it will just fail but since the
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# reseller account can connect to every account it is allowed
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# by the swift_auth middleware.
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force_tenant = None
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if ':' in access:
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access, force_tenant = access.split(':')
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# Authenticate request.
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creds = {'credentials': {'access': access,
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'token': token,
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'signature': signature}}
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creds_json = jsonutils.dumps(creds)
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self.logger.debug('Connecting to Keystone sending this JSON: %s' %
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creds_json)
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# NOTE(vish): We could save a call to keystone by having
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# keystone return token, tenant, user, and roles
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# from this call.
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#
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# NOTE(chmou): We still have the same problem we would need to
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# change token_auth to detect if we already
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# identified and not doing a second query and just
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# pass it through to swiftauth in this case.
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try:
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resp = self._json_request(creds_json)
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except ServiceError as e:
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resp = e.args[0]
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msg = 'Received error, exiting middleware with error: %s'
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self.logger.debug(msg % (resp.status_code))
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return resp(environ, start_response)
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self.logger.debug('Keystone Reply: Status: %d, Output: %s' % (
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resp.status_code, resp.content))
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try:
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identity_info = resp.json()
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token_id = str(identity_info['access']['token']['id'])
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tenant = identity_info['access']['token']['tenant']
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except (ValueError, KeyError):
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error = 'Error on keystone reply: %d %s'
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self.logger.debug(error % (resp.status_code, str(resp.content)))
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return self.deny_request('InvalidURI')(environ, start_response)
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req.headers['X-Auth-Token'] = token_id
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tenant_to_connect = force_tenant or tenant['id']
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self.logger.debug('Connecting with tenant: %s' % (tenant_to_connect))
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new_tenant_name = '%s%s' % (self.reseller_prefix, tenant_to_connect)
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environ['PATH_INFO'] = environ['PATH_INFO'].replace(account,
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new_tenant_name)
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return self.app(environ, start_response)
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def filter_factory(global_conf, **local_conf):
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"""Returns a WSGI filter app for use with paste.deploy."""
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conf = global_conf.copy()
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conf.update(local_conf)
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def auth_filter(app):
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return S3Token(app, conf)
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return auth_filter
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