如何让Python2生成与Python3一致的AWS SES SMTP凭证？

以下是修改后的脚本，可同时在Python2和Python3环境中生成一致且有效的AWS SES SMTP凭证：

#!/usr/bin/env python
# 兼容Python2和Python3

import hmac
import hashlib
import base64
import sys
import boto3
import json
from botocore.exceptions import ClientError

def get_secretmanager():
    secret_name = "test"
    region_name = "us-west-2"
    session = boto3.session.Session()
    client = session.client(
        service_name='secretsmanager',
        region_name=region_name
    )

    try:
        get_secret_value_response = client.get_secret_value(
            SecretId=secret_name
        )
    except ClientError as e:
        raise e

    # 解密并解析密钥
    secret = get_secret_value_response['SecretString']
    response = json.loads(secret)
    # 兼容Python2的unicode转str
    access_key = str(response['Access Key Id']) if sys.version_info[0] == 2 else response['Access Key Id']
    secret_key = str(response['Secret Access Key']) if sys.version_info[0] == 2 else response['Secret Access Key']
    return access_key, secret_key

SMTP_REGIONS = [
    'us-east-2',       # US East (Ohio)
    'us-east-1',       # US East (N. Virginia)
    'us-west-2',       # US West (Oregon)
    'ap-south-1',      # Asia Pacific (Mumbai)
    'ap-northeast-2',  # Asia Pacific (Seoul)
    'ap-southeast-1',  # Asia Pacific (Singapore)
    'ap-southeast-2',  # Asia Pacific (Sydney)
    'ap-northeast-1',  # Asia Pacific (Tokyo)
    'ca-central-1',    # Canada (Central)
    'eu-central-1',    # Europe (Frankfurt)
    'eu-west-1',       # Europe (Ireland)
    'eu-west-2',       # Europe (London)
    'sa-east-1',       # South America (Sao Paulo)
    'us-gov-west-1',   # AWS GovCloud (US)
]

# 签名计算固定参数，请勿修改
DATE = "11111111"
SERVICE = "ses"
MESSAGE = "SendRawEmail"
TERMINAL = "aws4_request"
VERSION = 0x04

def sign(key, msg):
    # 处理Python2/3的字符串/字节差异
    if sys.version_info[0] == 2:
        return hmac.new(key, msg, hashlib.sha256).digest()
    else:
        return hmac.new(key, msg.encode('utf-8'), hashlib.sha256).digest()

def calculate_key(secret_access_key, region):
    if region not in SMTP_REGIONS:
        raise ValueError("The " + region+ " Region doesn't have an SMTP endpoint.")

    # 初始密钥编码兼容
    initial_key = "AWS4" + secret_access_key if sys.version_info[0] == 2 else ("AWS4" + secret_access_key).encode('utf-8')
    
    signature = sign(initial_key, DATE)
    signature = sign(signature, region)
    signature = sign(signature, SERVICE)
    signature = sign(signature, TERMINAL)
    signature = sign(signature, MESSAGE)
    
    # 版本字节生成兼容
    if sys.version_info[0] == 2:
        version_byte = chr(VERSION)
        signature_and_version = version_byte + signature
    else:
        signature_and_version = bytes([VERSION]) + signature
    
    smtp_password = base64.b64encode(signature_and_version)
    
    # Base64结果解码兼容
    return smtp_password if sys.version_info[0] == 2 else smtp_password.decode('utf-8')

def get_keys():
    accesskey, secretkey = get_secretmanager() 
    mailsecret = calculate_key(secretkey, "us-west-2")
    return accesskey, mailsecret

print(get_keys())

关键修改说明： #

1. 字符串与字节编码适配：

   • Python2中str与字节无区分，直接传入hmac.new；Python3中需将字符串转为UTF-8字节。
   • 初始密钥AWS4 + secret_access_key在两个版本中分别以字符串和字节形式传入签名函数。

2. 版本字节生成：

   • Python2使用chr(VERSION)生成单字节字符，Python3使用bytes([VERSION])生成字节对象，确保签名前的版本标识一致。

3. Base64结果处理：

   • Python2中base64.b64encode直接返回字符串，Python3中返回字节对象，需解码为字符串后返回。

4. Secrets Manager返回值处理：

   • Python2中json.loads返回unicode类型，转换为str避免后续编码冲突。

内容的提问来源于stack exchange，提问作者Tony Frank