sm2加解密代码

以下是使用Python语言实现SM2的加解密代码（需要使用pycryptodomex库）：

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
from Crypto.PublicKey import ECC
from Crypto.Cipher import PKCS1_v1_5
from Crypto.PublicKey import RSA
from Crypto.Signature import pkcs1_15
from Crypto.Hash import SHA256
import binascii

def sm2_encrypt(data, public_key):
    # 将公钥转换为ECC类型
    ecc_public_key = ECC.import_key(public_key)
    # 获取公钥的xy坐标
    x, y = ecc_public_key.pointQ.x, ecc_public_key.pointQ.y
    # 将数据进行填充
    padded_data = pad(data.encode(), AES.block_size)
    # 生成随机数k
    k = ECC.generate(curve='sm2p256v1').d
    # 计算椭圆曲线点C1
    C1 = k * ecc_public_key.generator
    C1_x_bytes = C1.x.to_bytes(32, 'big')
    C1_y_bytes = C1.y.to_bytes(32, 'big')
    # 计算C3
    hashed_data = SHA256.new(padded_data)
    C3 = hashed_data.digest()
    # 计算C2
    # 将公钥的xy坐标拼接成一个字节数组
    xy_bytes = x.to_bytes(32, 'big') + y.to_bytes(32, 'big')
    # 计算SM3哈希值
    hashed_xy_data = sm3_hash(xy_bytes)
    # 计算加密密钥
    kdf_key = hashed_xy_data + b'\x01'
    # 将随机数k转换为字节数组
    k_bytes = k.to_bytes(32, 'big')
    # 计算加密因子u
    u = sm3_kdf(k_bytes, 32, kdf_key)
    # 将加密因子u转换为整数
    u_int = int.from_bytes(u, 'big')
    # 将填充后的数据分组
    groups = [padded_data[i:i + 16] for i in range(0, len(padded_data), 16)]
    # 计算加密后的数据
    C2 = b''
    for group in groups:
        m_int = int.from_bytes(group, 'big')
        c_int = (m_int + u_int) % ecc_public_key.order
        C2 += c_int.to_bytes(16, 'big')
    # 将加密结果拼接成一个字节数组
    encrypted_data = C1_x_bytes + C1_y_bytes + C3 + C2
    # 将加密结果进行BASE64编码
    encrypted_data_base64 = base64.b64encode(encrypted_data).decode()
    return encrypted_data_base64

def sm2_decrypt(data, private_key):
    # 将私钥转换为ECC类型
    ecc_private_key = ECC.import_key(private_key)
    # 将加密数据进行BASE64解码
    encrypted_data = base64.b64decode(data)
    # 分离出C1、C3和C2
    C1_x_bytes = encrypted_data[0:32]
    C1_y_bytes = encrypted_data[32:64]
    C3 = encrypted_data[64:96]
    C2 = encrypted_data[96:]
    # 计算椭圆曲线点C1
    C1_x = int.from_bytes(C1_x_bytes, 'big')
    C1_y = int.from_bytes(C1_y_bytes, 'big')
    C1 = ECC.EccPoint(C1_x, C1_y, curve='sm2p256v1')
    # 计算SM3哈希值
    hashed_xy_data = sm3_hash(private_key.public_key().export_key(format='DER')[31:])
    # 计算加密密钥
    kdf_key = hashed_xy_data + b'\x01'
    # 计算加密因子u
    u = sm3_kdf(C1_x_bytes + C1_y_bytes, 32, kdf_key)
    # 将加密因子u转换为整数
    u_int = int.from_bytes(u, 'big')
    # 计算填充后的数据
    padded_data = b''
    for i in range(0, len(C2), 16):
        c_int = int.from_bytes(C2[i:i + 16], 'big')
        m_int = (c_int - u_int) % ecc_private_key.order
        padded_data += m_int.to_bytes(16, 'big')
    # 将填充后的数据进行解填充
    original_data = unpad(padded_data, AES.block_size).decode()
    return original_data

其中，`sm3_hash`和`sm3_kdf`是SM3哈希算法和密钥派生函数的实现，可以参考SM3算法的标准文档进行实现。另外，这里使用了AES算法对数据进行填充和解填充。