SM2——适用于前后端（java+vue）公用的SM2国密加解密传输

一、SM2国密加解密算法

1.1、pom文件引入依赖包

 <dependency>
     <groupId>org.bouncycastle</groupId>
     <artifactId>bcprov-jdk18on</artifactId>
     <version>1.72</version>
 </dependency>

1.2、SM2加解密工具类

SM2加解密工具类

package com.xz.utils;
import org.bouncycastle.asn1.gm.GMNamedCurves;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.params.*;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.util.encoders.Hex;

import java.math.BigInteger;
import java.security.*;
import java.security.spec.ECGenParameterSpec;
import java.util.HashMap;
import java.util.Map;


/**
 * 适用于前后端公用的SM2秘钥生成、加解密工具类
 */
public class SimpSM2Util {
    /**
     * 公钥常量
     */
    public static final String KEY_PUBLIC_KEY = "publicKey";
    /**
     * 私钥返回值常量
     */
    public static final String KEY_PRIVATE_KEY = "privateKey";

    /**
     * SM2加密算法
     * @param publicKey     公钥
     * @param data          明文数据
     * @return
     */
    public static String encrypt(String publicKey, String data) {
        // 获取一条SM2曲线参数
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        // 构造ECC算法参数，曲线方程、椭圆曲线G点、大整数N
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        //提取公钥点
        ECPoint pukPoint = sm2ECParameters.getCurve().decodePoint(Hex.decode(publicKey));
        // 公钥前面的02或者03表示是压缩公钥，04表示未压缩公钥, 04的时候，可以去掉前面的04
        ECPublicKeyParameters publicKeyParameters = new ECPublicKeyParameters(pukPoint, domainParameters);

        SM2Engine sm2Engine = new SM2Engine(SM2Engine.Mode.C1C3C2);
        // 设置sm2为加密模式
        sm2Engine.init(true, new ParametersWithRandom(publicKeyParameters, new SecureRandom()));

        byte[] arrayOfBytes = null;
        try {
            byte[] in = data.getBytes();
            arrayOfBytes = sm2Engine.processBlock(in, 0, in.length);
        } catch (Exception e) {
            System.out.println("SM2加密时出现异常:"+e.getMessage());
        }
        return Hex.toHexString(arrayOfBytes);

    }

    /**
     * SM2解密算法
     * @param privateKey        私钥
     * @param cipherData        密文数据
     * @return
     */
    public static String decrypt(String privateKey, String cipherData) {
        // 使用BC库加解密时密文以04开头，传入的密文前面没有04则补上
        if (!cipherData.startsWith("04")){
            cipherData = "04" + cipherData;
        }
        byte[] cipherDataByte = Hex.decode(cipherData);
        BigInteger privateKeyD = new BigInteger(privateKey, 16);
        //获取一条SM2曲线参数
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        //构造domain参数
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        ECPrivateKeyParameters privateKeyParameters = new ECPrivateKeyParameters(privateKeyD, domainParameters);

        SM2Engine sm2Engine = new SM2Engine(SM2Engine.Mode.C1C3C2);
        // 设置sm2为解密模式
        sm2Engine.init(false, privateKeyParameters);

        String result = "";
        try {
            byte[] arrayOfBytes = sm2Engine.processBlock(cipherDataByte, 0, cipherDataByte.length);
            return new String(arrayOfBytes);
        } catch (Exception e) {
            System.out.println("SM2解密时出现异常:"+e.getMessage());
        }
        return result;
    }
 
    /**
     * 生成密钥
     */
    public static Map<String, String> createKey() throws Exception{
        ECGenParameterSpec sm2Spec = new ECGenParameterSpec("sm2p256v1");
        // 获取一个椭圆曲线类型的密钥对生成器
        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();
        PublicKey publicKey = keyPair.getPublic();
        BCECPublicKey p=(BCECPublicKey)publicKey;
        System.out.println("publicKey："+Hex.toHexString(p.getQ().getEncoded(false)));
        PrivateKey privateKey = keyPair.getPrivate();
        BCECPrivateKey s=(BCECPrivateKey)privateKey;
        System.out.println("privateKey："+Hex.toHexString(s.getD().toByteArray()));
        Map<String, String> result = new HashMap<>();
        result.put(KEY_PUBLIC_KEY, Hex.toHexString(p.getQ().getEncoded(false)));
        result.put(KEY_PRIVATE_KEY, Hex.toHexString(s.getD().toByteArray()));
        return result;
    }

}

1.3、测试类

测试类

public static void main(String[] args) throws Exception {
      Map<String, String> key = createKey();
       String publicKey = key.get(KEY_PUBLIC_KEY);
       System.out.println("公钥："+publicKey);
       String privateKey = key.get(KEY_PRIVATE_KEY);
       System.out.println("私钥："+privateKey);

       String str="hello java123456";
       System.out.println("加密前结果："+str);
       String encrypt = encrypt(publicKey, str);
       System.out.println("加密后结果："+encrypt);
       String decrypt = decrypt(privateKey, encrypt);
       System.out.println("解密后结果："+decrypt);
}