Python：hmac 库高级用法举例和应用详解

import hmac
import hashlib

# 场景说明：生成HMAC码以确保传输数据的完整性和来源
secret_key = b'supersecretkey'  # 定义密钥
message = b'This is a secret message'  # 要验证的消息

# 使用密钥和消息生成HMAC码
hmac_code = hmac.new(secret_key, message, hashlib.sha256).hexdigest()
print(f"The HMAC code is: {hmac_code}")  # 打印生成的HMAC码

# 验证消息的HMAC码
message_to_verify = b'This is a secret message'
received_hmac_code = hmac_code
expected_hmac_code = hmac.new(secret_key, message_to_verify, hashlib.sha256).hexdigest()

# 如果收到的HMAC码与期望的HMAC码匹配，则消息未被篡改
if received_hmac_code == expected_hmac_code:
    print("The message is authentic and has not been tampered with.")
else:
    print("The message has been tampered with or the HMAC code is incorrect.")

import hmac
import hashlib
import requests

# 场景说明：在API请求中使用HMAC进行身份验证
secret_key = b'apisecretkey'  # API密钥
data = b'{"username": "user1", "action": "login"}'  # 请求数据
api_endpoint = 'https://api.example.com/login'  # API端点

# 生成请求数据的HMAC码
signature = hmac.new(secret_key, data, hashlib.sha256).hexdigest()

# 发送请求时将HMAC码作为头部信息包含在内
headers = {
    'Content-Type': 'application/json',
    'Authorization': f'HMAC {signature}'
}
response = requests.post(api_endpoint, data=data, headers=headers)

# 检查响应状态码，确保请求成功
if response.status_code == 200:
    print("Request was authenticated and processed successfully.")
else:
    print("Failed to authenticate or process the request.")

import hmac
import hashlib

# 场景说明：在文件传输通信中确保文件的完整性
secret_key = b'filetransfersecret'  # 定义密钥
file_path = 'example_file.txt'  # 要传输的文件路径

# 读取文件内容
with open(file_path, 'rb') as f:
    file_data = f.read()

# 计算文件的HMAC码
file_hmac_code = hmac.new(secret_key, file_data, hashlib.sha256).hexdigest()
print(f"File HMAC code: {file_hmac_code}")  # 打印文件的HMAC码

# 假设我们在传输后收到了文件和对应的HMAC码
received_file_data = file_data  # 在实际的接收场景中，这会是接收的数据
received_hmac_code = file_hmac_code  # 在实际的接收场景中，这会是接收的HMAC码

# 验证接收的文件是否完整
expected_hmac_code = hmac.new(secret_key, received_file_data, hashlib.sha256).hexdigest()
if received_hmac_code == expected_hmac_code:
    print("The received file is authentic and has not been tampered with.")
else:
    print("The received file has been tampered with or the HMAC code is incorrect.")