创建 AWS V4 签名 url 以从 ScaleWay Object Storage 下载文件

如何解决创建 AWS V4 签名 url 以从 ScaleWay Object Storage 下载文件

我正在尝试创建 [1] AWS V4 签名 URL 以下载存储在 ScaleWay 对象存储存储桶中的文件。我使用了 AWS [2] 站点中的 python 示例并对其进行了修改，但无法使其正常工作。当我尝试访问生成的链接时，我收到了 403 响应 [3]，您可以在下面看到。

我将生成 403 链接的 python 脚本 [4] 复制到此处。

你能看一下它，让我知道我做错了什么吗？为什么我不能生成正确的签名？

[1]：由 [4] python 脚本生成的 URL：https://laboschqpa.s3.pl-waw.scw.cloud/1SorNemSorCpp.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=<I censored this for the question>%2F20210120%2Fpl-waw%2Fs3%2Faws4_request&X-Amz-Date=20210120T011857Z&X-Amz-Expires=3000&X-Amz-SignedHeaders=host&X-Amz-Signature=8ff4a56eef6dbd555a9b92ce2ac291488fabc6cb97b26711b6eeebfb0052ce15

[2]：AWS 网站上的 Python 示例：https://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html#sig-v4-examples-get-query-string

[3]：访问生成的链接时从 scaleway API 得到的 403 响应：<Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><RequestId>txb1179690b7a94d92a899a-0060035729</RequestId></Error>

[4]：我尝试生成链接的 python 脚本：

# copyright 2010-2019 Amazon.com,Inc. or its affiliates. All Rights Reserved.
#
# This file is licensed under the Apache License,Version 2.0 (the "License").
# You may not use this file except in compliance with the License. A copy of the
# License is located at
#
# http://aws.amazon.com/apache2.0/
#
# This file 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.
#
# ABOUT THIS PYTHON SAMPLE: This sample is part of the AWS General Reference
# Signing AWS API Requests top available at
# https://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html
#

# AWS Version 4 signing example

# IAM API (createuser)

# See: http://docs.aws.amazon.com/general/latest/gr/sigv4_signing.html
# This version makes a GET request and passes request parameters
# and authorization information in the query string
import sys,os,base64,datetime,hashlib,hmac,urllib
import requests  # pip install requests


# ************* REQUEST VALUES ScaleWay *************
method = 'GET'
service = 's3'
host = 'laboschqpa.s3.pl-waw.scw.cloud'
region = 'pl-waw'
endpoint = 'https://laboschqpa.s3.pl-waw.scw.cloud/1SorNemSorCpp.png'
access_key = '<I censored this for the question>'
secret_key = '<I censored this for the question>'


# Key derivation functions. See:
# http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-python
def sign(key,msg):
    return hmac.new(key,msg.encode('utf-8'),hashlib.sha256).digest()


def getSignatureKey(key,dateStamp,regionName,serviceName):
    kDate = sign(('AWS4' + key).encode('utf-8'),dateStamp)
    kRegion = sign(kDate,regionName)
    kService = sign(kRegion,serviceName)
    kSigning = sign(kService,'aws4_request')
    return kSigning


if access_key is None or secret_key is None:
    print('No access key is available.')
    sys.exit()

# Create a date for headers and the credential string
t = datetime.datetime.utcNow()
amz_date = t.strftime('%Y%m%dT%H%M%sZ')  # Format date as YYYYMMDD'T'HHMMSS'Z'
datestamp = t.strftime('%Y%m%d')  # Date w/o time,used in credential scope

# ************* TASK 1: CREATE A CANONICAL REQUEST *************
# http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html

# Because almost all information is being passed in the query string,# the order of these steps is slightly different than examples that
# use an authorization header.

# Step 1: Define the verb (GET,POST,etc.)--already done.

# Step 2: Create canonical URI--the part of the URI from domain to query
# string (use '/' if no path)
canonical_uri = '/1SorNemSorCpp.png'

# Step 3: Create the canonical headers and signed headers. Header names
# must be trimmed and lowercase,and sorted in code point order from
# low to high. Note trailing \n in canonical_headers.
# signed_headers is the list of headers that are being included
# as part of the signing process. For requests that use query strings,# only "host" is included in the signed headers.
canonical_headers = 'host:' + host + '\n'
signed_headers = 'host'

# Match the algorithm to the hashing algorithm you use,either SHA-1 or
# SHA-256 (recommended)
algorithm = 'AWS4-HMAC-SHA256'
credential_scope = datestamp + '/' + region + '/' + service + '/' + 'aws4_request'
credential_scope_quoted = datestamp + '%2F' + region + '%2F' + service + '%2F' + 'aws4_request'

# Step 4: Create the canonical query string. In this example,request
# parameters are in the query string. Query string values must
# be URL-encoded (space=%20). The parameters must be sorted by name.
# use urllib.parse.quote_plus() if using Python 3

# canonical_querystring = 'Action=createuser&UserName=NewUser&Version=2010-05-08'
canonical_querystring = 'X-Amz-Algorithm=AWS4-HMAC-SHA256'
canonical_querystring += '&X-Amz-Credential=' + access_key + '%2F' + credential_scope_quoted
canonical_querystring += '&X-Amz-Date=' + amz_date
canonical_querystring += '&X-Amz-Expires=3000'
canonical_querystring += '&X-Amz-SignedHeaders=' + signed_headers

# Step 5: Create payload hash. For GET requests,the payload is an
# empty string ("").
payload_hash = hashlib.sha256(('').encode('utf-8')).hexdigest()

# Step 6: Combine elements to create canonical request
canonical_request = method + '\n' + canonical_uri + '\n' + canonical_querystring + '\n' + canonical_headers + '\n' + signed_headers + '\n' + payload_hash

# ************* TASK 2: CREATE THE STRING TO SIGN*************
string_to_sign = algorithm + '\n' + amz_date + '\n' + credential_scope + '\n' + hashlib.sha256(
    canonical_request.encode('utf-8')).hexdigest()

# ************* TASK 3: CALculaTE THE SIGNATURE *************
# Create the signing key
signing_key = getSignatureKey(secret_key,datestamp,region,service)

# Sign the string_to_sign using the signing_key
signature = hmac.new(signing_key,(string_to_sign).encode("utf-8"),hashlib.sha256).hexdigest()

# ************* TASK 4: ADD SIGNING informatION TO THE REQUEST *************
# The auth information can be either in a query string
# value or in a header named Authorization. This code shows how to put
# everything into a query string.
canonical_querystring += '&X-Amz-Signature=' + signature

# ************* SEND THE REQUEST *************
# The 'host' header is added automatically by the Python 'request' lib. But it
# must exist as a header in the request.
request_url = endpoint + "?" + canonical_querystring

print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++')
print('Request URL = ' + request_url)
r = requests.get(request_url)

print('\nRESPONSE++++++++++++++++++++++++++++++++++++')
print('Response code: %d\n' % r.status_code)
print(r.text)

解决方法

如果您使用 GET 请求，则不应使用空字符串的哈希值（如官方示例中所述）作为规范请求，而应使用原始的“UNSIGNED-PAYLOAD”字符串。

举个例子：

您的规范请求将如下所示：

GET
/untitled1
X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=CENSOREDACCESSKEYID%2F20210121%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20210121T002816Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host
host:laboschqpa.s3.eu-central-1.amazonaws.com

host
UNSIGNED-PAYLOAD

而不是这样：

GET
/untitled1
X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=CENSOREDACCESSKEYID%2F20210121%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20210121T002816Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host
host:laboschqpa.s3.eu-central-1.amazonaws.com

host
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855