1、在pom.xml文件中，引入依赖类库

<dependency><groupId>commons-codec</groupId><artifactId>commons-codec</artifactId><version>1.11</version>
</dependency><!-- bcprov-jdk15to18-->
<dependency><groupId>org.bouncycastle</groupId><artifactId>bcprov-jdk15to18</artifactId><version>1.69</version>
</dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.25</version>
</dependency>

2、工具代码

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.spec.ECGenParameterSpec;
import java.security.spec.KeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.engines.SM2Engine.Mode;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.signers.SM2Signer;
import org.bouncycastle.jcajce.provider.asymmetric.util.ECUtil;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;/*** SM2 是国家密码管理局于 2010 年发布的一种国产公钥密码算法，它采用了椭圆曲线密码体制，其安全性已被国际公认。* SM2 算法的主要特点是安全性高、效率高、易于实现，因此被广泛应用于电子商务、电子政务、金融等领域。** SM2 算法由以下几个部分组成：** * 椭圆曲线：SM2 算法采用了 256 位超安全的椭圆曲线，其曲线方程为：*    y^2 = x^3 + a*x + b (mod p)*    其中，a 和 b 是曲线参数，p 是曲线阶。* * 基点：SM2 算法采用了曲线上的两个基点 G 和 P，其中 G 是生成点，P 是公钥点。* * * 消息加密：SM2 算法使用公钥加密，私钥解密。加密过程如下：*    1. 选择一个随机数 k，并计算 k*G。*    2. 将明文 M 与 k*G 进行异或运算，得到密文 C。* * * 消息解密：SM2 算法使用私钥解密，过程如下：*    1. 计算 k^-1。*    2. 将密文 C 与 k^-1*G 进行异或运算，得到明文 M。*/
public class Sm2Utils {private static Logger log = LoggerFactory.getLogger(Sm2Utils.class);public Sm2Utils() {}//生成密钥对public static KeyPair generateSm2KeyPair() {try {ECGenParameterSpec sm2Spec = new ECGenParameterSpec("prime256v1");KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC", new BouncyCastleProvider());SecureRandom random = new SecureRandom();kpg.initialize(sm2Spec, random);KeyPair keyPair = kpg.generateKeyPair();return keyPair;} catch (Exception var4) {log.error("generate sm2 key pail failed:", var4.getMessage(), var4);throw new RuntimeException("生成密钥对失败");}}//加密public static byte[] encrypt(byte[] data, byte[] key) throws Exception {KeySpec keySpec = new X509EncodedKeySpec(key);PublicKey publicKey = KeyFactory.getInstance("EC", new BouncyCastleProvider()).generatePublic(keySpec);ECPublicKeyParameters parameters = (ECPublicKeyParameters)ECUtil.generatePublicKeyParameter(publicKey);CipherParameters pubKeyParameters = new ParametersWithRandom(parameters);SM2Engine engine = new SM2Engine(Mode.C1C2C3);engine.init(true, pubKeyParameters);return engine.processBlock(data, 0, data.length);}//解密public static byte[] decrypt(byte[] data, byte[] key) throws Exception {KeySpec keySpec = new PKCS8EncodedKeySpec(key);KeyFactory keyfactory = KeyFactory.getInstance("EC", new BouncyCastleProvider());PrivateKey privateKey = keyfactory.generatePrivate(keySpec);CipherParameters privateKeyParameters = ECUtil.generatePrivateKeyParameter(privateKey);SM2Engine engine = new SM2Engine(Mode.C1C2C3);engine.init(false, privateKeyParameters);byte[] byteDate = engine.processBlock(data, 0, data.length);return byteDate;}//签名public static byte[] sign(byte[] data, byte[] key) throws Exception {SM2Signer signer = new SM2Signer();KeySpec keySpec = new PKCS8EncodedKeySpec(key);KeyFactory keyfactory = KeyFactory.getInstance("EC", new BouncyCastleProvider());PrivateKey privateKey = keyfactory.generatePrivate(keySpec);ECPrivateKeyParameters keyParameters = (ECPrivateKeyParameters)ECUtil.generatePrivateKeyParameter(privateKey);CipherParameters param = new ParametersWithRandom(keyParameters);signer.init(true, param);signer.update(data, 0, data.length);return signer.generateSignature();}//验签public static boolean verify(byte[] data, byte[] sign, byte[] key) throws Exception {SM2Signer signer = new SM2Signer();KeySpec keySpec = new X509EncodedKeySpec(key);PublicKey publicKey = KeyFactory.getInstance("EC", new BouncyCastleProvider()).generatePublic(keySpec);CipherParameters param = ECUtil.generatePublicKeyParameter(publicKey);signer.init(false, param);signer.update(data, 0, data.length);return signer.verifySignature(sign);}public static void main(String[] args) throws Exception {//生成密钥对KeyPair keyPair = generateSm2KeyPair();String publicKey = Base64.encodeBase64String(keyPair.getPublic().getEncoded());String privateKey = Base64.encodeBase64String(keyPair.getPrivate().getEncoded());System.out.println("sm2公钥字符串：" + publicKey);System.out.println("sm2私钥字符串：" + privateKey);//加密前内容String plaintext = "SM2 Test";//签名String signature = Base64.encodeBase64String(sign(plaintext.getBytes("utf-8"), keyPair.getPrivate().getEncoded()));System.out.println("签名: " + signature);//公钥加密String ciphertext = Base64.encodeBase64String( encrypt(plaintext.getBytes("utf-8"), Base64.decodeBase64(publicKey)) );System.out.println("密文: " + ciphertext);//验证boolean result = verify(plaintext.getBytes("utf-8"), Base64.decodeBase64(signature), keyPair.getPublic().getEncoded());System.out.println("验签结果: " + result);//私钥解密plaintext = new String( decrypt(Base64.decodeBase64(ciphertext), Base64.decodeBase64(privateKey)), "utf-8");System.out.println("明文: " + plaintext);}
}