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
|
# -*- coding: utf-8 -*-
# pylint: disable-all
#
# Copyright (c) 2012-2013 Paul Tax <paultax@gmail.com> All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# 3. Neither the name of Infrae nor the names of its contributors may
# be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INFRAE OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import hmac
from base64 import encodebytes as encodestring
from email.utils import formatdate
from hashlib import sha1 as sha
from urllib.parse import unquote, urlparse
from requests.auth import AuthBase
class S3Auth(AuthBase):
"""Attaches AWS Authentication to the given Request object."""
service_base_url = 's3.amazonaws.com'
# List of Query String Arguments of Interest
special_params = [
'acl', 'location', 'logging', 'partNumber', 'policy', 'requestPayment',
'torrent', 'versioning', 'versionId', 'versions', 'website', 'uploads',
'uploadId', 'response-content-type', 'response-content-language',
'response-expires', 'response-cache-control', 'delete', 'lifecycle',
'response-content-disposition', 'response-content-encoding', 'tagging',
'notification', 'cors'
]
def __init__(self, access_key, secret_key, service_url=None):
if service_url:
self.service_base_url = service_url
self.access_key = str(access_key)
self.secret_key = str(secret_key)
def __call__(self, r):
# Create date header if it is not created yet.
if 'date' not in r.headers and 'x-amz-date' not in r.headers:
r.headers['date'] = formatdate(
timeval=None,
localtime=False,
usegmt=True)
signature = self.get_signature(r)
signature = signature.decode('utf-8')
r.headers['Authorization'] = 'AWS %s:%s' % (self.access_key, signature)
return r
def get_signature(self, r):
canonical_string = self.get_canonical_string(
r.url, r.headers, r.method)
key = self.secret_key.encode('utf-8')
msg = canonical_string.encode('utf-8')
h = hmac.new(key, msg, digestmod=sha)
return encodestring(h.digest()).strip()
def get_canonical_string(self, url, headers, method):
parsedurl = urlparse(url)
objectkey = parsedurl.path[1:]
query_args = sorted(parsedurl.query.split('&'))
bucket = parsedurl.netloc[:-len(self.service_base_url)]
if len(bucket) > 1:
# remove last dot
bucket = bucket[:-1]
interesting_headers = {
'content-md5': '',
'content-type': '',
'date': ''}
for key in headers:
lk = key.lower()
try:
if isinstance(lk, bytes):
lk = lk.decode('utf-8')
except UnicodeDecodeError:
pass
if headers[key] and (lk in interesting_headers.keys()
or lk.startswith('x-amz-')):
interesting_headers[lk] = headers[key].strip()
# If x-amz-date is used it supersedes the date header.
if 'x-amz-date' in interesting_headers:
interesting_headers['date'] = ''
buf = '%s\n' % method
for key in sorted(interesting_headers.keys()):
val = interesting_headers[key]
if key.startswith('x-amz-'):
buf += '%s:%s\n' % (key, val)
else:
buf += '%s\n' % val
# append the bucket if it exists
if bucket != '':
buf += '/%s' % bucket
# add the objectkey. even if it doesn't exist, add the slash
buf += '/%s' % objectkey
params_found = False
# handle special query string arguments
for q in query_args:
k = q.split('=')[0]
if k in self.special_params:
buf += '&' if params_found else '?'
params_found = True
try:
k, v = q.split('=', 1)
except ValueError:
buf += q
else:
# Riak CS multipart upload ids look like this, `TFDSheOgTxC2Tsh1qVK73A==`,
# is should be escaped to be included as part of a query string.
#
# A requests mp upload part request may look like
# resp = requests.put(
# 'https://url_here',
# params={
# 'partNumber': 1,
# 'uploadId': 'TFDSheOgTxC2Tsh1qVK73A=='
# },
# data='some data',
# auth=S3Auth('access_key', 'secret_key')
# )
#
# Requests automatically escapes the values in the `params` dict, so now
# our uploadId is `TFDSheOgTxC2Tsh1qVK73A%3D%3D`,
# if we sign the request with the encoded value the signature will
# not be valid, we'll get 403 Access Denied.
# So we unquote, this is no-op if the value isn't encoded.
buf += '{key}={value}'.format(key=k, value=unquote(v))
return buf
|
