Python实现sm4_GCM
时间: 2024-10-12 15:17:10 浏览: 70
在Python中,SM4是一种对称密钥加密算法,而GCM(Galois/Counter Mode)是一种常用的块密码模式,用于数据加密和认证。如果你想要在Python中实现SM4-GCM模式,通常会依赖于像`cryptography`这样的库,它提供了高级的加密支持。
首先,你需要安装`cryptography`库,如果尚未安装,可以使用pip命令:
```bash
pip install cryptography
```
然后你可以使用该库的`ciphers`模块中的`AES-GCM`类结合SM4算法,虽然直接SM4-GCM不是标准提供的,但是可以通过包装实现。这里是一个简化的示例:
```python
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend
def sm4_gcm_encrypt(plaintext, key, associated_data=None):
backend = default_backend()
sm4_cipher = Cipher(algorithms.SM4(key), modes.GCM(associated_data or b''), backend)
encryptor = sm4_cipher.encryptor()
ciphertext = encryptor.update(plaintext) + encryptor.finalize()
tag = encryptor.tag
return ciphertext, tag
def sm4_gcm_decrypt(ciphertext, key, tag, associated_data=None):
backend = default_backend()
sm4_cipher = Cipher(algorithms.SM4(key), modes.GCM(associated_data or b'', tag), backend)
decryptor = sm4_cipher.decryptor()
plaintext = decryptor.update(ciphertext) + decryptor.finalize()
return plaintext
# 使用示例
key = b'secret_sm4_key'
plaintext = b'this is a secret message'
ciphertext, tag = sm4_gcm_encrypt(plaintext, key)
recovered_plaintext = sm4_gcm_decrypt(ciphertext, key, tag)
assert plaintext == recovered_plaintext, "Decryption failed"
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