基于Java的SM4（ECB模式，CBC模式）对称加解密实现

import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.BufferedBlockCipher;
import org.bouncycastle.crypto.engines.SM4Engine;
import org.bouncycastle.crypto.modes.ECBBlockCipher;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.paddings.ZeroBytePadding;
import org.bouncycastle.crypto.params.ParametersWithIV;
 
public class SM4Util {
 
    // ECB模式加密
    public static byte[] encryptECB(byte[] keyBytes, byte[] data) {
        KeyParameter key = new KeyParameter(keyBytes);
        BlockCipher engine = new ECBBlockCipher(new SM4Engine());
        BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
        cipher.init(true, key);
        byte[] result = new byte[cipher.getOutputSize(data.length)];
        int length = cipher.processBytes(data, 0, data.length, result, 0);
        cipher.doFinal(result, length);
        return result;
    }
 
    // ECB模式解密
    public static byte[] decryptECB(byte[] keyBytes, byte[] data) {
        KeyParameter key = new KeyParameter(keyBytes);
        BlockCipher engine = new ECBBlockCipher(new SM4Engine());
        BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
        cipher.init(false, key);
        byte[] result = new byte[cipher.getOutputSize(data.length)];
        int length = cipher.processBytes(data, 0, data.length, result, 0);
        cipher.doFinal(result, length);
        return result;
    }
 
    // CBC模式加密
    public static byte[] encryptCBC(byte[] keyBytes, byte[] ivBytes, byte[] data) {
        KeyParameter key = new KeyParameter(keyBytes);
        ParametersWithIV params = new ParametersWithIV(key, ivBytes);
        BlockCipher engine = new SM4Engine();
        BufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new CBCBlockCipher(engine), new ZeroBytePadding());
        cipher.init(true, params);
        byte[] result = new byte[cipher.getOutputSize(data.length)];
        int length = cipher.processBytes(data, 0, data.length, result, 0);
        cipher.doFinal(result, length);
        return result;
    }
 
    // CBC模式解密
    public static byte[] decryptCBC(byte[] keyBytes, byte[] ivBytes, byte[] data) {
        KeyParameter key = new KeyParameter(keyBytes);
        ParametersWithIV params = new ParametersWithIV(key, ivBytes);
        BlockCipher engine = new S