ADD file via upload

server.py

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+import os
+import socket
+from Crypto.Cipher import AES, PKCS1_OAEP
+from Crypto.PublicKey import RSA
+from Crypto.Signature import pkcs1_15
+from Crypto.Hash import SHA256
+from Crypto.Util.Padding import unpad
+
+
+def generate_keys_if_not_exists():
+    """生成公钥和私钥，如果文件不存在"""
+    if not os.path.exists('receiver_public.pem') or not os.path.exists('receiver_private.pem'):
+        print("正在生成公钥和私钥...")
+        generate_keys()
+    else:
+        print("公钥和私钥已存在。")
+
+
+def generate_keys():
+    """生成公钥和私钥并保存为文件"""
+    key = RSA.generate(2048)
+
+    # 导出私钥
+    private_key = key.export_key()
+    with open('receiver_private.pem', 'wb') as f:
+        f.write(private_key)
+    print("私钥已保存为 'receiver_private.pem'")
+
+    # 导出公钥
+    public_key = key.publickey().export_key()
+    with open('receiver_public.pem', 'wb') as f:
+        f.write(public_key)
+    print("公钥已保存为 'receiver_public.pem'")
+
+# 读取私钥
+def load_private_key():
+    with open('receiver_private.pem', 'rb') as f:
+        private_key = RSA.import_key(f.read())
+    return private_key
+
+# 读取发送方公钥
+def load_public_key():
+    with open('public.pem', 'rb') as f:
+        public_key = RSA.import_key(f.read())
+    return public_key
+
+# 解密文件
+def decrypt_file(encrypted_session_key, iv, ciphertext, private_key):
+    # 使用 RSA 解密 AES 密钥
+
+    cipher_rsa = PKCS1_OAEP.new(private_key)
+    session_key = cipher_rsa.decrypt(encrypted_session_key)
+
+    # 使用 AES 解密文件内容
+    mode = AES.MODE_CBC if iv else AES.MODE_ECB  # 如果有 IV 则使用 CBC 模式，否则使用 ECB 模式
+
+    cipher_aes = AES.new(session_key, mode, iv=iv if iv else None)
+
+    # 解密并去除填充
+    try:
+        plaintext = unpad(cipher_aes.decrypt(ciphertext), AES.block_size)
+    except ValueError:
+        print("错误：填充数据不正确或密文已损坏。")
+        raise
+
+    return plaintext
+
+# 验证签名
+def verify_signature(filename, signature, public_key):
+    # 计算文件的 SHA-256 哈希值
+    hash_obj = SHA256.new()
+    with open(filename, 'rb') as f:
+        while chunk := f.read(4096):
+            hash_obj.update(chunk)
+
+    # 使用公钥验证签名
+    verifier = pkcs1_15.new(public_key)
+    try:
+        verifier.verify(hash_obj, signature)
+        print("签名验证成功。")
+    except (ValueError, TypeError):
+        print("签名验证失败。")
+
+# 服务器接收加密文件并解密
+def receive_encrypted_file(host, port):
+    # 监听客户端连接
+    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server_socket.bind((host, port))
+    server_socket.listen(1)
+
+    print(f"服务器正在监听 {host}:{port} ...")
+    client_socket, addr = server_socket.accept()
+    print(f"与客户端 {addr} 建立了连接。")
+
+    # 接收加密的 AES 密钥、IV 和加密的文件内容
+    encrypted_session_key = client_socket.recv(256)  # RSA 密钥长度 2048 位 (256 字节)
+    iv = client_socket.recv(16)  # AES 块大小为 16 字节
+    ciphertext = client_socket.recv(16)
+    signature = client_socket.recv(256)
+
+    # 解密文件
+    private_key = load_private_key()
+    decrypted_file = decrypt_file(encrypted_session_key, iv, ciphertext, private_key)
+    # 保存解密后的文件
+    with open('received_file.txt', 'wb') as f:
+        f.write(decrypted_file)
+    with open('received_file.txt', 'r', encoding='utf-8') as f:
+        print("解密后的文件内容：")
+        print(f.read())
+    # 验证签名
+    verify_signature('received_file.txt', signature, load_public_key())
+
+
+
+    print("文件接收并解密成功。")
+    client_socket.close()
+
+# 使用示例
+generate_keys_if_not_exists()
+receive_encrypted_file('127.0.0.1', 59290)