2024-2025-2 《Python程序设计》实验三报告

学号 20241311 2024-2025-2《Python程序设计》实验三报告

课程：《Python程序设计》
班级： 2413
姓名： 廖江泽
学号：20241311
实验教师：王志强
实验日期：2025年4月16日
必修/选修： 公选课

1.实验内容

• 创建服务端和客户端，服务端在特定端口监听多个客户请求。客户端和服务端通过Socket套接字（TCP/UDP）进行通信。

2. 实验过程及结果

• 获取无线局域网适配器WLAN中的IPv4地址：
  
• 关闭电脑防火墙：
  

-进行通讯：
客户端代码

import socket

# 创建 socket 对象
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# 连接到服务器
server_address = ('192.168.83.9', 9999)
client_socket.connect(server_address)

while True:
    # 发送消息给服务器
    message = input('请输入要发送给服务器的消息: ')
    client_socket.send(message.encode('utf-8'))

    # 接收服务器消息
    data = client_socket.recv(1024).decode('utf-8')
    if not data:
        break
    print('服务器说: {}'.format(data))
    # if (input("是否继续Y/N？")=="N"):
    #     break

# 关闭连接
client_socket.close()

服务端代码：

import socket

# 创建 socket 对象
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# 绑定地址和端口
server_address = ('192.168.83.9', 9999)
server_socket.bind(server_address)

# 监听连接
server_socket.listen(1)
print('服务器正在监听 {}:{}'.format(*server_address))

# 接受客户端连接
client_socket, client_address = server_socket.accept()
print('接受来自 {} 的连接'.format(client_address))

while True:
    # 接收客户端消息
    data = client_socket.recv(1024).decode('utf-8')
    if not data:
        break
    print('客户端说: {}'.format(data))

    # 发送消息给客户端
    message = input('请输入要发送给客户端的消息: ')
    client_socket.send(message.encode('utf-8'))
    if input("是否要继续？Y/N")=="N":
        break

# 关闭连接
client_socket.close()
server_socket.close()

• 运行结果如下：
  
  

• 采用AES加密：

客户端：

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
import os
import socket

# 密钥和初始化向量，需和服务端保持一致
key = b'Sixteen byte key'
iv = b'InitializationVe'

def aes_encrypt(data):
    try:
        cipher = AES.new(key, AES.MODE_CBC, iv)
        padded_data = pad(data.encode('utf-8'), AES.block_size)
        encrypted_data = cipher.encrypt(padded_data)
        return encrypted_data
    except Exception as e:
        print(f"加密过程出错: {e}")
        return None

server_address = ('192.168.83.9', 8888)
file_name = 'send_file.txt'
log_file = 'client_log.txt'
client_socket = None

try:
    client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    client_socket.connect(server_address)

    use_existing_file = input("是否使用已有的文件？(Y/N): ").strip().upper()
    script_dir = os.path.dirname(os.path.abspath(__file__))

    if use_existing_file == 'Y':
        file_path = os.path.join(script_dir, file_name)
        if not os.path.exists(file_path):
            print(f"文件 {file_name} 不存在，将创建新文件并提示输入内容。")
            use_existing_file = 'N'
    if use_existing_file == 'N':
        file_path = os.path.join(script_dir, file_name)
        print("\n请输入要发送的内容（输入空行结束）:")
        content = []
        while True:
            line = input()
            if not line:
                break
            content.append(line)
        content = '\n'.join(content)
        with open(file_path, 'w', encoding='utf-8') as file:
            file.write(content)
        print(f"内容已保存到 {file_name}")

    with open(file_path, 'r', encoding='utf-8') as file:
        plaintext_data = file.read()

    encrypted_data = aes_encrypt(plaintext_data)
    if encrypted_data is None:
        raise ValueError("加密失败，无法继续执行。")

    with open(log_file, 'w', encoding='utf-8') as log:
        log.write("加密前的内容:\n")
        log.write(plaintext_data)
        log.write("\n\n加密后的内容:\n")
        log.write(encrypted_data.hex())

    confirm = input("\n是否发送文件内容？(Y/N): ").strip().upper()
    if confirm == 'Y':
        client_socket.send(encrypted_data)
        print('数据已加密并发送')
    else:
        print("发送已取消。")

except ConnectionRefusedError:
    print("无法连接到服务器，请检查服务端是否启动。")
except FileNotFoundError:
    print("文件未找到，请检查文件路径。")
except Exception as e:
    print(f"发生未知错误: {e}")
finally:
    if client_socket:
        client_socket.close()

服务端：

from Crypto.Cipher import AES
from Crypto.Util.Padding import unpad
import socket
import os

# 密钥和初始化向量，需和客户端保持一致
key = b'Sixteen byte key'
iv = b'InitializationVe'

def aes_decrypt(encrypted_data):
    try:
        cipher = AES.new(key, AES.MODE_CBC, iv)
        decrypted_data = cipher.decrypt(encrypted_data)
        unpadded_data = unpad(decrypted_data, AES.block_size)
        return unpadded_data.decode('utf-8')
    except Exception as e:
        print(f"解密过程出错: {e}")
        return None

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_address = ('192.168.83', 8888)
log_file = 'server_log.txt'
client_socket = None

try:
    server_socket.bind(server_address)
    server_socket.listen(1)
    print(f'服务器正在监听 {server_address[0]}:{server_address[1]}')

    client_socket, client_address = server_socket.accept()
    print(f'接受来自 {client_address} 的连接')

    encrypted_data = client_socket.recv(4096)
    decrypted_data = aes_decrypt(encrypted_data)
    if decrypted_data is None:
        raise ValueError("解密失败，无法继续执行。")

    with open(log_file, 'w', encoding='utf-8') as log:
        log.write("接收到的加密内容:\n")
        log.write(encrypted_data.hex())
        log.write("\n\n解密后的内容:\n")
        log.write(decrypted_data)

    script_dir = os.path.dirname(os.path.abspath(__file__))
    file_path = os.path.join(script_dir, 'received_file.txt')
    with open(file_path, 'w', encoding='utf-8') as file:
        file.write(decrypted_data)
    print('数据已解密并保存到 received_file.txt')

except OSError as e:
    print(f"服务器绑定或监听时出现错误: {e}")
except FileNotFoundError:
    print("文件未找到，请检查文件路径。")
except Exception as e:
    print(f"发生未知错误: {e}")
finally:
    if client_socket:
        client_socket.close()
    if server_socket:
        server_socket.close()

• 运行结果如下：
  
  

• 上传至码云：
  

3. 实验过程中遇到的问题和解决过程

• 问题1：在进行不同计算机之间的通信时，显示“目标计算机积极防御”。
• 问题1解决方案：询问同学，知道了是防火墙的问题关闭防火墙

4. 参考资料

• 《0基础学python》