1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
# Copyright 2012 OpenStack Foundation
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""Starting point for routing EC2 requests."""
import hashlib
from oslo_config import cfg
from oslo_log import log as logging
from oslo_serialization import jsonutils
import requests
import six
import webob.dec
from keystonemiddleware.i18n import _
keystone_ec2_opts = [
cfg.StrOpt('url',
default='http://localhost:5000/v3/ec2tokens',
help='URL to get token from ec2 request.'),
cfg.StrOpt('keyfile',
help='Required if EC2 server requires client certificate.'),
cfg.StrOpt('certfile',
help='Client certificate key filename. Required if EC2 server '
'requires client certificate.'),
cfg.StrOpt('cafile',
help='A PEM encoded certificate authority to use when '
'verifying HTTPS connections. Defaults to the system '
'CAs.'),
cfg.BoolOpt('insecure', default=False,
help='Disable SSL certificate verification.'),
]
CONF = cfg.CONF
CONF.register_opts(keystone_ec2_opts, group='keystone_ec2_token')
PROTOCOL_NAME = 'EC2 Token Authentication'
class EC2Token(object):
"""Authenticate an EC2 request with keystone and convert to token."""
def __init__(self, application, conf):
super(EC2Token, self).__init__()
self._application = application
self._logger = logging.getLogger(conf.get('log_name', __name__))
self._logger.debug('Starting the %s component', PROTOCOL_NAME)
def _ec2_error_response(self, code, message):
"""Helper to construct an EC2 compatible error message."""
self._logger.debug('EC2 error response: %(code)s: %(message)s',
{'code': code, 'message': message})
resp = webob.Response()
resp.status = 400
resp.headers['Content-Type'] = 'text/xml'
error_msg = str('<?xml version="1.0"?>\n'
'<Response><Errors><Error><Code>%s</Code>'
'<Message>%s</Message></Error></Errors></Response>' %
(code, message))
if six.PY3:
error_msg = error_msg.encode()
resp.body = error_msg
return resp
def _get_signature(self, req):
"""Extract the signature from the request.
This can be a get/post variable or for version 4 also in a header
called 'Authorization'.
- params['Signature'] == version 0,1,2,3
- params['X-Amz-Signature'] == version 4
- header 'Authorization' == version 4
"""
sig = req.params.get('Signature') or req.params.get('X-Amz-Signature')
if sig is None and 'Authorization' in req.headers:
auth_str = req.headers['Authorization']
sig = auth_str.partition("Signature=")[2].split(',')[0]
return sig
def _get_access(self, req):
"""Extract the access key identifier.
For version 0/1/2/3 this is passed as the AccessKeyId parameter, for
version 4 it is either an X-Amz-Credential parameter or a Credential=
field in the 'Authorization' header string.
"""
access = req.params.get('AWSAccessKeyId')
if access is None:
cred_param = req.params.get('X-Amz-Credential')
if cred_param:
access = cred_param.split("/")[0]
if access is None and 'Authorization' in req.headers:
auth_str = req.headers['Authorization']
cred_str = auth_str.partition("Credential=")[2].split(',')[0]
access = cred_str.split("/")[0]
return access
@webob.dec.wsgify()
def __call__(self, req):
# NOTE(alevine): We need to calculate the hash here because
# subsequent access to request modifies the req.body so the hash
# calculation will yield invalid results.
body_hash = hashlib.sha256(req.body).hexdigest()
signature = self._get_signature(req)
if not signature:
msg = _("Signature not provided")
return self._ec2_error_response("AuthFailure", msg)
access = self._get_access(req)
if not access:
msg = _("Access key not provided")
return self._ec2_error_response("AuthFailure", msg)
if 'X-Amz-Signature' in req.params or 'Authorization' in req.headers:
auth_params = {}
else:
# Make a copy of args for authentication and signature verification
auth_params = dict(req.params)
# Not part of authentication args
auth_params.pop('Signature', None)
headers = req.headers
if six.PY3:
# NOTE(andrey-mp): jsonutils dumps it as list of keys without
# conversion instead real dict
headers = {k: headers[k] for k in headers}
cred_dict = {
'access': access,
'signature': signature,
'host': req.host,
'verb': req.method,
'path': req.path,
'params': auth_params,
'headers': headers,
'body_hash': body_hash
}
if "ec2" in CONF.keystone_ec2_token.url:
creds = {'ec2Credentials': cred_dict}
else:
creds = {'auth': {'OS-KSEC2:ec2Credentials': cred_dict}}
creds_json = jsonutils.dumps(creds)
headers = {'Content-Type': 'application/json'}
verify = not CONF.keystone_ec2_token.insecure
if verify and CONF.keystone_ec2_token.cafile:
verify = CONF.keystone_ec2_token.cafile
cert = None
if (CONF.keystone_ec2_token.certfile and
CONF.keystone_ec2_token.keyfile):
cert = (CONF.keystone_ec2_certfile,
CONF.keystone_ec2_token.keyfile)
elif CONF.keystone_ec2_token.certfile:
cert = CONF.keystone_ec2_token.certfile
response = requests.request('POST', CONF.keystone_ec2_token.url,
data=creds_json, headers=headers,
verify=verify, cert=cert)
# NOTE(vish): We could save a call to keystone by
# having keystone return token, tenant,
# user, and roles from this call.
status_code = response.status_code
if status_code != 200:
msg = _('Error response from keystone: %s') % response.reason
self._logger.debug(msg)
return self._ec2_error_response("AuthFailure", msg)
try:
token_id = response.headers['x-subject-token']
except (AttributeError, KeyError):
msg = _("Failure parsing response from keystone")
self._logger.exception(msg)
return self._ec2_error_response("AuthFailure", msg)
# Authenticated!
req.headers['X-Auth-Token'] = token_id
return self._application
def filter_factory(global_conf, **local_conf):
"""Return a WSGI filter app for use with paste.deploy."""
conf = global_conf.copy()
conf.update(local_conf)
def auth_filter(app):
return EC2Token(app, conf)
return auth_filter
def app_factory(global_conf, **local_conf):
conf = global_conf.copy()
conf.update(local_conf)
return EC2Token(None, conf)
|
