Aws lambda aws lambda的招摇过市模式

我正在使用AWS版本4签名过程为带有API ListFunctions的AWS lambda服务创建签名。我得到了正确的URL，这在postman上是有效的。但在运行python文件时，我得到了403状态错误，这表明“我们计算的请求签名与您提供的签名不匹配。检查您的AWS秘密访问密钥和签名方法。有关详细信息，请参阅服务文档。“。有人能帮我解决此问题吗？提前谢谢

python file :

    # Copyright 2010-2018 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

    # EC2 API (DescribeRegions)

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

    # ************* REQUEST VALUES *************
    method = 'GET'
    service = 'lambda'
    host = 'lambda.us-east-1.amazonaws.com'
    region = 'us-east-1'
    endpoint = 'https://lambda.us-east-1.amazonaws.com/2015-03-31/functions'
    request_parameters = 'Action=ListFunctions&Version=2015-03-31'

    # 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

    # Read AWS access key from env. variables or configuration file. Best practice is NOT
    # to embed credentials in code.
    access_key = ""
    secret_key = ""
    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()
    amzdate = t.strftime('%Y%m%dT%H%M%SZ')
    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

    # Step 1 is to 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 = '/'

    # Step 3: Create the canonical query string. In this example (a GET request),
    # request parameters are in the query string. Query string values must
    # be URL-encoded (space=%20). The parameters must be sorted by name.
    # For this example, the query string is pre-formatted in the request_parameters variable.
    canonical_querystring = request_parameters

    # Step 4: 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 that there is a trailing \n.
    canonical_headers = 'host:' + host + '\n' + 'x-amz-date:' + amzdate + '\n'

    # Step 5: Create the list of signed headers. This lists the headers
    # in the canonical_headers list, delimited with ";" and in alpha order.
    # Note: The request can include any headers; canonical_headers and
    # signed_headers lists those that you want to be included in the
    # hash of the request. "Host" and "x-amz-date" are always required.
    signed_headers = 'host;x-amz-date'

    # Step 6: Create payload hash (hash of the request body content). For GET
    # requests, the payload is an empty string ("").
    payload_hash = hashlib.sha256(('').encode('utf-8')).hexdigest()

    # Step 7: 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*************
    # 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'
    string_to_sign = algorithm + '\n' +  amzdate + '\n' +  credential_scope + '\n' +  hashlib.sha256(canonical_request.encode('utf-8')).hexdigest()

    # ************* TASK 3: CALCULATE THE SIGNATURE *************
    # Create the signing key using the function defined above.
    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 signing information can be either in a query string value or in
    # a header named Authorization. This code shows how to use a header.
    # Create authorization header and add to request headers
    authorization_header = algorithm + ' ' + 'Credential=' + access_key + '/' + credential_scope + ', ' +  'SignedHeaders=' + signed_headers + ', ' + 'Signature=' + signature

    # The request can include any headers, but MUST include "host", "x-amz-date",
    # and (for this scenario) "Authorization". "host" and "x-amz-date" must
    # be included in the canonical_headers and signed_headers, as noted
    # earlier. Order here is not significant.
    # Python note: The 'host' header is added automatically by the Python 'requests' library.
    headers = {'x-amz-date':amzdate, 'Authorization':authorization_header}
    print(headers)

    # ************* SEND THE REQUEST *************
    request_url = endpoint + '?' + canonical_querystring

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

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

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问题是您没有正确设置AWS秘密访问密钥

解决方案：

转到AWS帐户的IAM部分，选择用户或创建一个

分配项目所需的特定角色

导航到用户帐户中的“安全凭据”选项卡

选择现有密钥或创建新密钥并查找AWS机密访问密钥

您可以在系统或代码中将AWS密钥设置为环境变量