SM2数据加密（单机模式）

import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
import org.bouncycastle.jce.spec.ECParameterSpec;

import java.security.*;

/**
 * SM2引擎类
 */
public class MySm2Engine {
    public static final int Type_Encode = 0;
    public static final int Type_Decode = 1;

    /**
     * 创建一个SM2引擎
     * @param pubKey
     * @param priKey
     * @param enOrde
     * @return
     * @throws Exception
     */
    public static SM2Engine createMySm2Engine(PublicKey pubKey,PrivateKey priKey,int enOrde) throws Exception {
        if (enOrde == Type_Encode) {
            ECPublicKeyParameters ecPublicKeyParameters = null;
            if (pubKey instanceof BCECPublicKey) {
                BCECPublicKey bcPubKey = (BCECPublicKey) pubKey;
                ECParameterSpec ecParameterSpec = bcPubKey.getParameters();
                ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                        ecParameterSpec.getG(), ecParameterSpec.getN());
                ecPublicKeyParameters = new ECPublicKeyParameters(bcPubKey.getQ(),ecDomainParameters);
            }
            SM2Engine sm2Engine = new SM2Engine();
            sm2Engine.init(true, new ParametersWithRandom(ecPublicKeyParameters, new SecureRandom()));
            return sm2Engine;
        }else {

            BCECPrivateKey bcecPrivateKey = (BCECPrivateKey) priKey;
            ECParameterSpec ecParameterSpec = bcecPrivateKey.getParameters();
            ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                    ecParameterSpec.getG(), ecParameterSpec.getN());
            ECPrivateKeyParameters ecPrivateKeyParameters = new ECPrivateKeyParameters(bcecPrivateKey.getD(),
                    ecDomainParameters);
            SM2Engine sm2Engine = new SM2Engine();
            sm2Engine.init(false, ecPrivateKeyParameters);
            return sm2Engine;
        }
    }
}

import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import org.bouncycastle.util.encoders.Hex;
import org.springframework.stereotype.Component;

import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.spec.ECGenParameterSpec;

/**
 * SM2算法工具类
 */
@Component("Sm2CryptTools")
public class Sm2CryptTools {
    private final KeyPair mKeyPair;
    public Sm2CryptTools() throws Exception {
        mKeyPair = initKey();
    }

    /**
     * 创建密钥对
     * @return 密钥对KeyPair
     * @throws Exception
     */
    public KeyPair initKey()  throws Exception{
        try {
            ECGenParameterSpec sm2Spec = new ECGenParameterSpec("sm2p256v1");
            // 获取一个椭圆曲线类型的密钥对生成器
            final KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC", new BouncyCastleProvider());
            // 使用SM2参数初始化生成器
            kpg.initialize(sm2Spec);
            // 获取密钥对
            KeyPair keyPair = kpg.generateKeyPair();
            return keyPair;
        }catch (Exception e) {
            throw new Exception(e);
        }
    }

    /**
     * sm2加密算法
     * @param pubkey：公钥
     * @param plainData：要加密的字符串
     * @return：加密结果
     */
    public String encrypt(PublicKey pubkey,String plainData) {
        try {
            SM2Engine sm2Engine = MySm2Engine.createMySm2Engine(pubkey,null,MySm2Engine.Type_Encode);
            //encrypt data
            byte[] bytes = null;
            try {
                byte[] in = plainData.getBytes(StandardCharsets.UTF_8);
                bytes = sm2Engine.processBlock(in,0, in.length);
            }
            catch (Exception e) {
                System.out.println("SM2加密失败:");
            }
            return Hex.toHexString(bytes);
        }catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * sm2解密算法
     * @param priKey：私钥
     * @param cipherData：要解密的字符串
     * @return
     */
    public String decrypt(PrivateKey priKey,String cipherData) {
        try {
            //init engine
            SM2Engine sm2Engine = MySm2Engine.createMySm2Engine(null,priKey,MySm2Engine.Type_Decode);

            //decrypt data
            byte[] cipherDataByte = Hex.decode(cipherData);
            byte[] bytes = sm2Engine.processBlock(cipherDataByte, 0, cipherDataByte.length);
            return new String(bytes, StandardCharsets.UTF_8);
        }catch (Exception e) {
            System.out.println("SM2解密失败:");
        }
        return null;
    }

    /**
     * 测试函数
     */
    public static void Sm2Test() {
        String dataStr = "hello ,2023!";
        try {
            Sm2CryptTools sm2CryptTools= new Sm2CryptTools();
            KeyPair keyPair = sm2CryptTools.mKeyPair;

            System.out.println("原始明文：" + dataStr);
            String resData = sm2CryptTools.encrypt(keyPair.getPublic(),dataStr);
            System.out.println("SM2加密后密文：" + resData);

            String resData2 = sm2CryptTools.decrypt(keyPair.getPrivate(),resData);
            System.out.println("SM2解密后明文：" + resData2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 主函数
     * @param args
     */
    public static void main(String[] args) {
        Sm2Test();
    }

}

        <dependency>
            <groupId>org.bouncycastle</groupId>
            <artifactId>bcprov-jdk15to18</artifactId>
            <version>1.64</version>
        </dependency>