国密SM2算法进行数据的加密、签名和验签、解密_前端sm2加密body跟签名用什么拼接好

一、背景介绍

数据的加解密有很多种方式，几种常用的加密算法如下：

DES（Data Encryption Standard）：对称算法，数据加密标准，速度较快，适用于加密大量数据的场合；

3DES（Triple DES）：是基于DES的对称算法，对一块数据用三个不同的密钥进行三次加密，强度更高；

RC2和RC4：对称算法，用变长密钥对大量数据进行加密，比 DES 快；

IDEA（International Data Encryption Algorithm）国际数据加密算法，使用 128 位密钥提供非常强的安全性；

RSA：由 RSA 公司发明，是一个支持变长密钥的公共密钥算法，需要加密的文件块的长度也是可变的，非对称算法

本文着重介绍SM2国密算法的使用，这是一款中国国家密码局发布的一款加密算法，本文介绍使用语言环境为java语言 

二、引入pom依赖

<dependency>
    <groupId>org.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.70</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <scope>provided</scope>
</dependency>

主要是引入了工具包和lombok依赖

 三、国密公私钥对工具类KeyUtils

package com.hl.sm2demo.util;

import lombok.extern.slf4j.Slf4j;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.security.*;
import java.security.spec.ECGenParameterSpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.Map;

/**
 * @ Description 国密公私钥对工具类
 */
@Slf4j
public class KeyUtils {
    public static final String PUBLIC_KEY = "publicKey";

    public static final String PRIVATE_KEY = "privateKey";

    /**
     * 生成国密公私钥对
     */
    public static Map<String, String> generateSmKey() throws Exception {
        KeyPairGenerator keyPairGenerator = null;
        SecureRandom secureRandom = new SecureRandom();
        ECGenParameterSpec sm2Spec = new ECGenParameterSpec("sm2p256v1");
        keyPairGenerator = KeyPairGenerator.getInstance("EC", new BouncyCastleProvider());
        keyPairGenerator.initialize(sm2Spec);
        keyPairGenerator.initialize(sm2Spec, secureRandom);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PrivateKey privateKey = keyPair.getPrivate();
        PublicKey publicKey = keyPair.getPublic();
        String publicKeyStr = new String(Base64.getEncoder().encode(publicKey.getEncoded()));
        String privateKeyStr = new String(Base64.getEncoder().encode(privateKey.getEncoded()));
        return Map.of(PUBLIC_KEY, publicKeyStr, PRIVATE_KEY, privateKeyStr);
    }

    /**
     * 将Base64转码的公钥串，转化为公钥对象
     */
    public static PublicKey createPublicKey(String publicKey) {
        PublicKey publickey = null;
        try {
            X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(publicKey));
            KeyFactory keyFactory = KeyFactory.getInstance("EC", new BouncyCastleProvider());
            publickey = keyFactory.generatePublic(publicKeySpec);
        } catch (Exception e) {
            log.error("将Base64转码的公钥串，转化为公钥对象异常：{}", e.getMessage(), e);
        }
        return publickey;
    }

    /**
     * 将Base64转码的私钥串，转化为私钥对象
     */
    public static PrivateKey createPrivateKey(String privateKey) {
        PrivateKey publickey = null;
        try {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(privateKey));
            KeyFactory keyFactory = KeyFactory.getInstance("EC", new BouncyCastleProvider());
            publickey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
        } catch (Exception e) {
            log.error("将Base64转码的私钥串，转化为私钥对象异常：{}", e.getMessage(), e);
        }
        return publickey;
    }

}

生成公私钥字符串map对象，公钥串转公钥对象方法和私钥串转私钥对象方法 

四、 SM2工具类

package com.hl.sm2demo.util;

import lombok.extern.slf4j.Slf4j;
import org.bouncycastle.asn1.gm.GMObjectIdentifiers;
import org.bouncycastle.crypto.InvalidCipherTextException;
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.provider.BouncyCastleProvider;
import org.bouncycastle.jce.spec.ECParameterSpec;

import java.security.*;

/**
 * @ Description SM2实现工具类
 */
@Slf4j
public class Sm2Util {

/*    这行代码是在Java中用于向安全系统添加Bouncy Castle安全提供器的。
    Bouncy Castle是一个流行的开源加密库，它提供了许多密码学算法和安全协议的实现。

    通过调用Security.addProvider并传入BouncyCastleProvider对象，你可以注册Bouncy Castle提供的安全服务和算法到Java的安全框架中。
    这样一来，你就可以在你的应用程序中使用Bouncy Castle所提供的加密算法、密钥生成和管理等功能。*/
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * 根据publicKey对原始数据data，使用SM2加密
     */
    public static byte[] encrypt(byte[] data, PublicKey publicKey) {
        ECPublicKeyParameters localECPublicKeyParameters = getEcPublicKeyParameters(publicKey);
        SM2Engine localSM2Engine = new SM2Engine();
        localSM2Engine.init(true, new ParametersWithRandom(localECPublicKeyParameters, new SecureRandom()));
        byte[] arrayOfByte2;
        try {
            arrayOfByte2 = localSM2Engine.processBlock(data, 0, data.length);
            return arrayOfByte2;
        } catch (InvalidCipherTextException e) {
            log.error("SM2加密失败:{}", e.getMessage(), e);
            return null;
        }
    }

    private static ECPublicKeyParameters getEcPublicKeyParameters(PublicKey publicKey) {
        ECPublicKeyParameters localECPublicKeyParameters = null;
        if (publicKey instanceof BCECPublicKey localECPublicKey) {
            ECParameterSpec localECParameterSpec = localECPublicKey.getParameters();
            ECDomainParameters localECDomainParameters = new ECDomainParameters(localECParameterSpec.getCurve(),
                    localECParameterSpec.getG(), localECParameterSpec.getN());
            localECPublicKeyParameters = new ECPublicKeyParameters(localECPublicKey.getQ(), localECDomainParameters);
        }
        return localECPublicKeyParameters;
    }

    /**
     * 根据privateKey对加密数据encode data，使用SM2解密
     */
    public static byte[] decrypt(byte[] encodeData, PrivateKey privateKey) {
        SM2Engine localSM2Engine = new SM2Engine();
        BCECPrivateKey sm2PriK = (BCECPrivateKey) privateKey;
        ECParameterSpec localECParameterSpec = sm2PriK.getParameters();
        ECDomainParameters localECDomainParameters = new ECDomainParameters(localECParameterSpec.getCurve(),
                localECParameterSpec.getG(), localECParameterSpec.getN());
        ECPrivateKeyParameters localECPrivateKeyParameters = new ECPrivateKeyParameters(sm2PriK.getD(),
                localECDomainParameters);
        localSM2Engine.init(false, localECPrivateKeyParameters);
        try {
            return localSM2Engine.processBlock(encodeData, 0, encodeData.length);
        } catch (InvalidCipherTextException e) {
            log.error("SM2解密失败:{}", e.getMessage(), e);
            return null;
        }
    }

    /**
     * 私钥签名
     */
    public static byte[] signByPrivateKey(byte[] data, PrivateKey privateKey) throws Exception {
        Signature sig = Signature.getInstance(GMObjectIdentifiers.sm2sign_with_sm3.toString(), BouncyCastleProvider.PROVIDER_NAME);
        sig.initSign(privateKey);
        sig.update(data);
        return sig.sign();
    }

    /**
     * 公钥验签
     */
    public static boolean verifyByPublicKey(byte[] data, PublicKey publicKey, byte[] signature) throws Exception {
        Signature sig = Signature.getInstance(GMObjectIdentifiers.sm2sign_with_sm3.toString(), BouncyCastleProvider.PROVIDER_NAME);
        sig.initVerify(publicKey);
        sig.update(data);
        return sig.verify(signature);
    }

}

五、案例测试Junit 

package com.hl.sm2demo;

import com.hl.sm2demo.util.KeyUtils;
import com.hl.sm2demo.util.Sm2Util;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.Base64;
import java.util.Map;

@SpringBootTest
class Sm2DemoApplicationTests {

    PublicKey publicKey = null;
    PrivateKey privateKey = null;


    @Test
    public void test() throws Exception {
        //生成公私钥对
        Map<String,String> keys = KeyUtils.generateSmKey();

        String testStr = "hello JAVA";
        System.out.println("原始字符串：" + testStr);
        System.out.println("公钥：" + keys.get(KeyUtils.PUBLIC_KEY));
        publicKey = KeyUtils.createPublicKey(keys.get(KeyUtils.PUBLIC_KEY));

        System.out.println("私钥：" + keys.get(KeyUtils.PRIVATE_KEY));
        privateKey = KeyUtils.createPrivateKey(keys.get(KeyUtils.PRIVATE_KEY));

        System.out.println();

        //公钥加密
        byte[] encrypt = Sm2Util.encrypt(testStr.getBytes(), publicKey);
        //加密转base64
        String encryptBase64Str = Base64.getEncoder().encodeToString(encrypt);
        System.out.println("加密数据：" + encryptBase64Str);
        //私钥签名,方便对方收到数据后用公钥验签
        byte[] sign = Sm2Util.signByPrivateKey(testStr.getBytes(), privateKey);
        System.out.println("数据签名：" + Base64.getEncoder().encodeToString(sign));

        //公钥验签，验证通过后再进行数据解密
        boolean b = Sm2Util.verifyByPublicKey(testStr.getBytes(), publicKey, sign);
        System.out.println("数据验签：" + b);
        //私钥解密
        byte[] decode = Base64.getDecoder().decode(encryptBase64Str);
        byte[] decrypt = Sm2Util.decrypt(decode, privateKey);
        assert decrypt != null;
        System.out.println("解密数据：" + new String(decrypt));
    }
}

测试代码主要逻辑：

密钥准备：首先生成一个公私钥对字符串，再使用工具分别转换为公私钥的java对象；

加密过程：把数据使用公钥加密，把密文转换成base64编码格式，再用私钥签名；

解密过程：拿到加密数据后用公钥验签，以确保密文数据没有被第三方拦截篡改，验证通过后，base64解码，最后使用私钥进行解密，还原数据

测试结果如下图：