用python实现sm4算法

以下是使用Python实现SM4算法的示例代码：

from Crypto.Cipher import SM4
from Crypto.Util.Padding import pad, unpad
from binascii import b2a_hex, a2b_hex

def sm4_encrypt(key, plaintext):
    cipher = SM4.new(key, SM4.MODE_ECB)
    padded_plaintext = pad(plaintext.encode(), SM4.block_size)
    ciphertext = cipher.encrypt(padded_plaintext)
    return b2a_hex(ciphertext).decode()

def sm4_decrypt(key, ciphertext):
    cipher = SM4.new(key, SM4.MODE_ECB)
    padded_plaintext = cipher.decrypt(a2b_hex(ciphertext))
    plaintext = unpad(padded_plaintext, SM4.block_size)
    return plaintext.decode()

# 示例用法
key = b'0123456789abcdef'  # 16字节的密钥
plaintext = 'Hello, World!'
ciphertext = sm4_encrypt(key, plaintext)
decrypted_text = sm4_decrypt(key, ciphertext)

print("加密结果:", ciphertext)
print("解密结果:", decrypted_text)