SM4国密算法加解密工具类（JAVA版）

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.Cipher;
import java.security.Security;
import java.util.Arrays;
 
public class SM4Utils {
    static {
        Security.addProvider(new BouncyCastleProvider());
    }
 
    public static byte[] encrypt(byte[] key, byte[] data) throws Exception {
        Cipher cipher = Cipher.getInstance("SM4", new BouncyCastleProvider());
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "SM4"));
        return cipher.doFinal(data);
    }
 
    public static byte[] decrypt(byte[] key, byte[] data) throws Exception {
        Cipher cipher = Cipher.getInstance("SM4", new BouncyCastleProvider());
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "SM4"));
        return cipher.doFinal(data);
    }
 
    // 测试加解密
    public static void main(String[] args) throws Exception {
        byte[] key = new byte[16]; // 16字节的SM4密钥
        byte[] data = "测试数据".getBytes("UTF-8");
 
        // 加密
        byte[] encryptedData = encrypt(key, data);
        System.out.println("加密后的数据: " + bytesToHex(encryptedData));
 
        // 解密
        byte[] decryptedData = decrypt(key, encryptedData);
        System.out.println("解密后的数据: " + new String(decryptedData, "UTF-8"));
    }
 
    // 字节数组转16进制字符串
    private static String bytesToHex(byte[] bytes) {
        StringBuilder hexBuilder = new StringBuilder();
        for (byte b : bytes) {
            hexBuilder.append(String.format("%02X", b));
        }
        return hexBuilder.toString();
    }
}

这段代码提供了使用SM4加密算法进行加密和解密的方法，同时包含了密钥生成、加密、解密的简单示例。注意，在实际应用中，密钥生成方式应更安全，并确保密钥的安全存储。