自动生成一个密钥，用AES对其进行加密，采用ECB模式，并把密文写到文件cipher-ecb.txt

这是一个相对复杂的问题，需要用到多个库和算法。以下是一份实现该要求的Python代码： ```python import os import random import math from Crypto.Cipher import AES from Crypto.Util.Padding import pad, unpad from Crypto.PublicKey import RSA # 生成会话密钥 def generate_session_key(key_size): return os.urandom(key_size) # RSA加密 def rsa_encrypt(public_key, data): cipher = RSA.importKey(public_key) return cipher.encrypt(data, None)[0] # RSA解密 def rsa_decrypt(private_key, data): cipher = RSA.importKey(private_key) return cipher.decrypt(data) # Feistel结构加密 def feistel_encrypt(data, key, rounds): block_size = len(data) // 2 left = data[:block_size] right = data[block_size:] for i in range(rounds): temp = left left = right right = bytearray() for j in range(block_size): right.append(temp[j] ^ key[j]) key = os.urandom(block_size) for j in range(block_size): right[j] ^= key[j] return right + left # Feistel结构解密 def feistel_decrypt(data, key, rounds): block_size = len(data) // 2 left = data[block_size:] right = data[:block_size] for i in range(rounds): temp = right right = left left = bytearray() for j in range(block_size): left.append(temp[j] ^ key[j]) key = os.urandom(block_size) for j in range(block_size): left[j] ^= key[j] return left + right # OFB模式加密 def ofb_encrypt(data, key, iv): cipher = AES.new(key, AES.MODE_ECB) block_size = cipher.block_size result = bytearray() for i in range(0, len(data), block_size): iv = cipher.encrypt(iv) block = data[i:i+block_size] result += bytearray([iv[j] ^ block[j] for j in range(block_size)]) return result # OFB模式解密 def ofb_decrypt(data, key, iv): cipher = AES.new(key, AES.MODE_ECB) block_size = cipher.block_size result = bytearray() for i in range(0, len(data), block_size): iv = cipher.encrypt(iv) block = data[i:i+block_size] result += bytearray([iv[j] ^ block[j] for j in range(block_size)]) return result # 加密文件 def encrypt_file(infile, outfile, public_key): key_size = 32 block_size = 16 rounds = 16 session_key = generate_session_key(key_size) encrypted_key = rsa_encrypt(public_key, session_key) with open(infile, 'rb') as fin, open(outfile, 'wb') as fout: iv = os.urandom(block_size) fout.write(encrypted_key) while True: data = fin.read(block_size) if not data: break encrypted_data = ofb_encrypt(data, session_key, iv) fout.write(encrypted_data) # 解密文件 def decrypt_file(infile, outfile, private_key): key_size = 32 block_size = 16 rounds = 16 with open(infile, 'rb') as fin, open(outfile, 'wb') as fout: session_key = rsa_decrypt(private_key, fin.read(key_size)) iv = os.urandom(block_size) while True: data = fin.read(block_size) if not data: break decrypted_data = ofb_decrypt(data, session_key, iv) fout.write(decrypted_data) # 测试代码 if __name__ == '__main__': # 生成RSA密钥对 key_size = 2048 key = RSA.generate(key_size) public_key = key.publickey().exportKey() private_key = key.exportKey() # 加密明文文件 infile = 'p_text.txt' outfile = 'c_text.txt' encrypt_file(infile, outfile, public_key) # 解密密文文件 infile = 'c_text.txt' outfile = 'p1_text.txt' decrypt_file(infile, outfile, private_key) # 检查解密结果是否与明文文件一致 with open('p_text.txt', 'rb') as fin1, open('p1_text.txt', 'rb') as fin2: if fin1.read() == fin2.read(): print('Decryption successful!') else: print('Decryption failed!') ``` 需要注意的是，本代码仅供学习和参考，实际应用中还需要进行更严格的测试和验证，以确保其安全性和正确性。

### 使用PyCryptodome库实现AES加密 安装`pycryptodome`之后，在Python脚本中可以利用该库来执行数据的加解密操作[^1]。 下面是一个使用PyCryptodome库进行AES加密的具体实例： ```python from Crypto.Cipher import AES from Crypto.Random import get_random_bytes from Crypto.Util.Padding import pad, unpad def encrypt_data(data, key): cipher = AES.new(key, AES.MODE_CBC) ct_bytes = cipher.encrypt(pad(data.encode('utf-8'), AES.block_size)) iv = cipher.iv return iv.hex() + ':' + ct_bytes.hex() key = get_random_bytes(32) # AES-256 requires a 32-byte key. data_to_encrypt = 'This is just an example.' encrypted_result = encrypt_data(data_to_encrypt, key) print(f'Encrypted data: {encrypted_result}') ``` 此代码片段展示了如何创建一个新的AES对象并指定工作模式为CBC（Cipher Block Chaining）。为了确保消息长度适合AES处理，应用了PKCS7填充方案。此外，初始化向量(`iv`)被转换成十六进制字符串并与密文一起返回以便后续解码过程能够获取必要的参数[^4]。 对于大文件而言，逐块读取和加密会更加高效而不是一次性加载整个文件到内存中完成全部加密流程[^2]。