我正在尝试创建[1]AWS V4签名url来下载存储在ScaleWay对象存储桶中的文件。我使用了AWS[2]站点上的python示例并对其进行了修改，但我无法使其正常工作。当我尝试访问生成的链接时，我得到一个403响应[3]，如下所示。
我复制我的python脚本[4]在这里产生403链接。
你能帮我看一下，告诉我哪里做错了吗?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，我从scaleway API获得的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: %dn' % r.status_code)
print(r.text)
如果您使用GET请求，您不应该对规范请求使用空字符串的散列(就像在官方示例中被告知的那样)，而是使用原始的"UNSIGNED-PAYLOAD"字符串。
例如:
你的规范请求看起来像这样:
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
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