Java国密加密SM2代码

Java国密加密算法SM2是一种基于椭圆曲线密码算法，广泛应用于国际标准化组织的密码算法标准中，如中国的SM2/SM3/SM4算法标准。

以下是一个简单的Java示例，展示了如何使用国密SM2算法进行公钥加密数据：

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.modes.GMTEncryptingState;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.digests.SM3Digest;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.jce.spec.ECPublicKeySpec;
import org.bouncycastle.jce.interfaces.ECPublicKey;
import java.security.KeyFactory;
import java.security.Security;
import java.security.SecureRandom;
import java.security.spec.X509EncodedKeySpec;
import java.util.Map;
 
public class SM2EncryptionExample {
    static {
        Security.addProvider(new BouncyCastleProvider());
    }
 
    public static void main(String[] args) throws Exception {
        // 初始化SM2算法需要的参数
        ECKeyPairGenerator keyGenerator = new ECKeyPairGenerator();
        keyGenerator.init(new ECKeyPairGenerator.ECKeyGenerationParameters(
                ECNistCurveTable.getCurveParameters(ECNistCurveTable.sm2p256v1),
                new SecureRandom()
        ));
        AsymmetricCipherKeyPair keyPair = keyGenerator.generateKeyPair();
        ECPrivateKeyParameters privateKey = (ECPrivateKeyParameters) keyPair.getPrivate();
        ECPublicKeyParameters publicKey = (ECPublicKeyParameters) keyPair.getPublic();
 
        // 公钥转换为Java标准格式
        byte[] publicKeyBytes = publicKey.getQ().getEncoded(false);
        X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(publicKeyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("ECDSA", "BC");
        ECPublicKey pubKey = (ECPublicKey) keyFactory.generatePublic(publicKeySpec);
 
        // 原始数据
        byte[] originalData = "Hello, SM2!".getBytes();
 
        // 使用SM2算法进行加密
        SM2Engine sm2Engine = new SM2Engine();
        sm2Engine.init(true, new ParametersWithRandom(publicKey,