Files
python-keystoneclient/keystoneclient/middleware/s3_token.py
Jamie Lennox 9fda5add29 Use requests library in S3 middleware
Convert the S3 token middleware to use the requests library. It does not
validate certificates as part of this patch to keep new functionality
isolated.

Change-Id: I0f26c80a969b919de80410af0a80920bd8493191
Closes-Bug: #1275598
2014-02-05 13:59:00 +10:00

264 lines
10 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 OpenStack Foundation
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011,2012 Akira YOSHIYAMA <akirayoshiyama@gmail.com>
# All Rights Reserved.
#
# 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.
# This source code is based ./auth_token.py and ./ec2_token.py.
# See them for their copyright.
"""
S3 TOKEN MIDDLEWARE
This WSGI component:
* Get a request from the swift3 middleware with an S3 Authorization
access key.
* Validate s3 token in Keystone.
* Transform the account name to AUTH_%(tenant_name).
"""
import logging
import urllib
import webob
import requests
from keystoneclient.openstack.common import jsonutils
PROTOCOL_NAME = 'S3 Token Authentication'
# TODO(kun): remove it after oslo merge this.
def split_path(path, minsegs=1, maxsegs=None, rest_with_last=False):
"""Validate and split the given HTTP request path.
**Examples**::
['a'] = split_path('/a')
['a', None] = split_path('/a', 1, 2)
['a', 'c'] = split_path('/a/c', 1, 2)
['a', 'c', 'o/r'] = split_path('/a/c/o/r', 1, 3, True)
:param path: HTTP Request path to be split
:param minsegs: Minimum number of segments to be extracted
:param maxsegs: Maximum number of segments to be extracted
:param rest_with_last: If True, trailing data will be returned as part
of last segment. If False, and there is
trailing data, raises ValueError.
:returns: list of segments with a length of maxsegs (non-existant
segments will return as None)
:raises: ValueError if given an invalid path
"""
if not maxsegs:
maxsegs = minsegs
if minsegs > maxsegs:
raise ValueError('minsegs > maxsegs: %d > %d' % (minsegs, maxsegs))
if rest_with_last:
segs = path.split('/', maxsegs)
minsegs += 1
maxsegs += 1
count = len(segs)
if (segs[0] or count < minsegs or count > maxsegs or
'' in segs[1:minsegs]):
raise ValueError('Invalid path: %s' % urllib.quote(path))
else:
minsegs += 1
maxsegs += 1
segs = path.split('/', maxsegs)
count = len(segs)
if (segs[0] or count < minsegs or count > maxsegs + 1 or
'' in segs[1:minsegs] or
(count == maxsegs + 1 and segs[maxsegs])):
raise ValueError('Invalid path: %s' % urllib.quote(path))
segs = segs[1:maxsegs]
segs.extend([None] * (maxsegs - 1 - len(segs)))
return segs
class ServiceError(Exception):
pass
class S3Token(object):
"""Auth Middleware that handles S3 authenticating client calls."""
def __init__(self, app, conf):
"""Common initialization code."""
self.app = app
self.logger = logging.getLogger(conf.get('log_name', __name__))
self.logger.debug('Starting the %s component' % PROTOCOL_NAME)
self.reseller_prefix = conf.get('reseller_prefix', 'AUTH_')
# where to find the auth service (we use this to validate tokens)
auth_host = conf.get('auth_host')
auth_port = int(conf.get('auth_port', 35357))
auth_protocol = conf.get('auth_protocol', 'https')
self.request_uri = '%s://%s:%s' % (auth_protocol, auth_host, auth_port)
# SSL
insecure = conf.get('insecure', False)
cert_file = conf.get('certfile')
key_file = conf.get('keyfile')
if insecure:
self.verify = False
elif cert_file and key_file:
self.verify = (cert_file, key_file)
elif cert_file:
self.verify = cert_file
else:
self.verify = None
def deny_request(self, code):
error_table = {
'AccessDenied': (401, 'Access denied'),
'InvalidURI': (400, 'Could not parse the specified URI'),
}
resp = webob.Response(content_type='text/xml')
resp.status = error_table[code][0]
resp.body = error_table[code][1]
resp.body = ('<?xml version="1.0" encoding="UTF-8"?>\r\n'
'<Error>\r\n <Code>%s</Code>\r\n '
'<Message>%s</Message>\r\n</Error>\r\n' %
(code, error_table[code][1]))
return resp
def _json_request(self, creds_json):
headers = {'Content-Type': 'application/json'}
try:
response = requests.post('%s/v2.0/s3tokens' % self.request_uri,
headers=headers, data=creds_json,
verify=self.verify)
except requests.exceptions.RequestException as e:
self.logger.info('HTTP connection exception: %s' % e)
resp = self.deny_request('InvalidURI')
raise ServiceError(resp)
if response.status_code < 200 or response.status_code >= 300:
self.logger.debug('Keystone reply error: status=%s reason=%s' %
(response.status_code, response.reason))
resp = self.deny_request('AccessDenied')
raise ServiceError(resp)
return response
def __call__(self, environ, start_response):
"""Handle incoming request. authenticate and send downstream."""
req = webob.Request(environ)
self.logger.debug('Calling S3Token middleware.')
try:
parts = split_path(req.path, 1, 4, True)
version, account, container, obj = parts
except ValueError:
msg = 'Not a path query, skipping.'
self.logger.debug(msg)
return self.app(environ, start_response)
# Read request signature and access id.
if 'Authorization' not in req.headers:
msg = 'No Authorization header. skipping.'
self.logger.debug(msg)
return self.app(environ, start_response)
token = req.headers.get('X-Auth-Token',
req.headers.get('X-Storage-Token'))
if not token:
msg = 'You did not specify a auth or a storage token. skipping.'
self.logger.debug(msg)
return self.app(environ, start_response)
auth_header = req.headers['Authorization']
try:
access, signature = auth_header.split(' ')[-1].rsplit(':', 1)
except ValueError:
msg = 'You have an invalid Authorization header: %s'
self.logger.debug(msg % (auth_header))
return self.deny_request('InvalidURI')(environ, start_response)
# NOTE(chmou): This is to handle the special case with nova
# when we have the option s3_affix_tenant. We will force it to
# connect to another account than the one
# authenticated. Before people start getting worried about
# security, I should point that we are connecting with
# username/token specified by the user but instead of
# connecting to its own account we will force it to go to an
# another account. In a normal scenario if that user don't
# have the reseller right it will just fail but since the
# reseller account can connect to every account it is allowed
# by the swift_auth middleware.
force_tenant = None
if ':' in access:
access, force_tenant = access.split(':')
# Authenticate request.
creds = {'credentials': {'access': access,
'token': token,
'signature': signature}}
creds_json = jsonutils.dumps(creds)
self.logger.debug('Connecting to Keystone sending this JSON: %s' %
creds_json)
# NOTE(vish): We could save a call to keystone by having
# keystone return token, tenant, user, and roles
# from this call.
#
# NOTE(chmou): We still have the same problem we would need to
# change token_auth to detect if we already
# identified and not doing a second query and just
# pass it through to swiftauth in this case.
try:
resp = self._json_request(creds_json)
except ServiceError as e:
resp = e.args[0]
msg = 'Received error, exiting middleware with error: %s'
self.logger.debug(msg % (resp.status_code))
return resp(environ, start_response)
self.logger.debug('Keystone Reply: Status: %d, Output: %s' % (
resp.status_code, resp.content))
try:
identity_info = resp.json()
token_id = str(identity_info['access']['token']['id'])
tenant = identity_info['access']['token']['tenant']
except (ValueError, KeyError):
error = 'Error on keystone reply: %d %s'
self.logger.debug(error % (resp.status_code, str(resp.content)))
return self.deny_request('InvalidURI')(environ, start_response)
req.headers['X-Auth-Token'] = token_id
tenant_to_connect = force_tenant or tenant['id']
self.logger.debug('Connecting with tenant: %s' % (tenant_to_connect))
new_tenant_name = '%s%s' % (self.reseller_prefix, tenant_to_connect)
environ['PATH_INFO'] = environ['PATH_INFO'].replace(account,
new_tenant_name)
return self.app(environ, start_response)
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 S3Token(app, conf)
return auth_filter