python实现des算法实现ECB/CBC/CFB/OFB模式

DES (Data Encryption Standard) 是一种经典的对称加密算法，Python 中可以使用 `pyDes` 或者 `cryptography` 库来实现它。以下是使用 `cryptography` 库来实现 DES 的 ECB、CBC、CFB 和 OFB 模式的基本步骤： 1. **安装所需库**: ```bash pip install cryptography ``` 2. **导入必要的模块**: ```python from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes from cryptography.hazmat.backends import default_backend ``` **ECB模式**（Electronic Codebook模式）: ```python def des_ecb_encrypt(plaintext, key): backend = default_backend() cipher = Cipher(algorithms.DESCryptor(key), modes.ECB(), backend) encryptor = cipher.encryptor() ciphertext = encryptor.update(plaintext) + encryptor.finalize() return ciphertext # 示例 key = b'sixteen byte key' plaintext = b'Some plaintext to encrypt' ciphertext = des_ecb_encrypt(plaintext, key) ``` **CBC模式**（Cipher Block Chaining模式）: ```python def des_cbc_encrypt(plaintext, iv, key): backend = default_backend() cipher = Cipher(algorithms.DESCryptor(key, mode=modes.CBC(iv)), backend) encryptor = cipher.encryptor() ciphertext = encryptor.update(plaintext) + encryptor.finalize() return ciphertext, iv # 示例 iv = b'This is an IV' ... ``` **CFB模式**（Cipher Feedback模式）: ```python def des_cfb_encrypt(plaintext, key, initial_vector, block_size=8): backend = default_backend() cipher = Cipher(algorithms.DESCryptor(key, mode=modes.CFB(initial_vector, block_size)), backend) encryptor = cipher.encryptor() ciphertext = encryptor.update(plaintext) + encryptor.finalize() return ciphertext # 示例 ... ``` **OFB模式**（Output Feedback模式）: ```python def des_ofb_encrypt(plaintext, key, initial_vector, block_size=8): backend = default_backend() cipher = Cipher(algorithms.DESCryptor(key, mode=modes.OFB(initial_vector, block_size)), backend) encryptor = cipher.encryptor() ciphertext = encryptor.update(plaintext) + encryptor.finalize() return ciphertext # 示例 ... ```