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);
  }
  

• 测试结果，如下图所示：