国密SM2: 加解密实现 java代码完整示例

叁歲伎倆 2024-03-26 13:05 108阅读 0赞

**目录**

具体Java代码SM2算法加解密实现Demo：

pom依赖引入 ：

> 国家密码管理局于2010年12月17日发布了SM2算法，并要求现有的基于RSA算法的电子认证系统、密钥管理系统、应用系统进升级改造，使用支持国密SM2算法的证书。

![a5e40cd725a67474441df8c4af8f2f1d.png][]

基于ECC椭圆曲线算法的SM2算法，则普遍采用256位密钥长度，它的单位安全强度相对较高，在工程应用中比较难以实现，破译或求解难度基本上是指数级的。因此，SM2算法可以用较少的计算能力提供比RSA算法更高的安全强度，而所需的密钥长度却远比RSA算法低。

<table style="width:554px;"> 
 <tbody> 
  <tr> 
   <td style="text-align:center;width:123px;">对比项目</td> 
   <td style="text-align:center;width:258px;">ECC加密算法</td> 
   <td style="text-align:center;width:169px;">RSA加密算法</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">密钥长度</td> 
   <td style="text-align:center;width:258px;">256位</td> 
   <td style="text-align:center;width:169px;">2048位</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">CPU占用</td> 
   <td style="text-align:center;width:258px;">较少</td> 
   <td style="text-align:center;width:169px;">较高</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">内存占用</td> 
   <td style="text-align:center;width:258px;">较少</td> 
   <td style="text-align:center;width:169px;">较高</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">网络消耗</td> 
   <td style="text-align:center;width:258px;">较低</td> 
   <td style="text-align:center;width:169px;">较高</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">加密效率</td> 
   <td style="text-align:center;width:258px;">较高</td> 
   <td style="text-align:center;width:169px;">一般</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">破解难度</td> 
   <td style="text-align:center;width:258px;">具有数据特性，破解难度大</td> 
   <td style="text-align:center;width:169px;">相对ECC理论上容易些</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">抗攻击性</td> 
   <td style="text-align:center;width:258px;">强</td> 
   <td style="text-align:center;width:169px;">一般</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">可扩展性</td> 
   <td style="text-align:center;width:258px;">强</td> 
   <td style="text-align:center;width:169px;">一般</td> 
  </tr> 
  <tr> 
   <td style="text-align:center;width:123px;">兼容范围</td> 
   <td style="text-align:center;width:258px;">支持新版浏览器和操作系统，但存在少数不支持平台，例如cPanel</td> 
   <td style="text-align:center;width:169px;">广泛支持</td> 
  </tr> 
 </tbody> 
</table>

#### **具体Java代码SM2算法加解密实现Demo：** ####

package org.example;
    
    import org.bouncycastle.asn1.gm.GMNamedCurves;
    import org.bouncycastle.asn1.x9.X9ECParameters;
    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 org.bouncycastle.jce.spec.ECPrivateKeySpec;
    import org.bouncycastle.jce.spec.ECPublicKeySpec;
    import org.bouncycastle.util.encoders.Hex;
    
    import java.math.BigInteger;
    import java.security.*;
    import java.security.spec.ECGenParameterSpec;
    
    /**
     * @ClassName SM2Utils
     * @Description SM2算法工具类
     */
    public class SM2Utils {
        public static KeyPair createECKeyPair() {
            final ECGenParameterSpec sm2Spec = new ECGenParameterSpec("sm2p256v1");
    
            // 获取一个椭圆曲线类型的密钥对生成器
            final KeyPairGenerator kpg;
            try {
                kpg = KeyPairGenerator.getInstance("EC", new BouncyCastleProvider());
                kpg.initialize(sm2Spec, new SecureRandom());
    
                return kpg.generateKeyPair();
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        public static String encrypt(String publicKeyHex, String data) {
            return encrypt(getECPublicKeyByPublicKeyHex(publicKeyHex), data, 1);
        }
    
        public static String encrypt(BCECPublicKey publicKey, String data, int modeType) {
            //加密模式
            SM2Engine.Mode mode = SM2Engine.Mode.C1C3C2;
            if (modeType != 1) {
                mode = SM2Engine.Mode.C1C2C3;
            }
            ECParameterSpec ecParameterSpec = publicKey.getParameters();
            ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                    ecParameterSpec.getG(), ecParameterSpec.getN());
            ECPublicKeyParameters ecPublicKeyParameters = new ECPublicKeyParameters(publicKey.getQ(), ecDomainParameters);
     
            SM2Engine sm2Engine = new SM2Engine(mode);
    
            sm2Engine.init(true, new ParametersWithRandom(ecPublicKeyParameters, new SecureRandom()));
            byte[] arrayOfBytes = null;
            try {
                byte[] in = data.getBytes("utf-8");
            
                arrayOfBytes = sm2Engine.processBlock(in, 0, in.length);
            } catch (Exception e) {
                System.out.println("SM2加密时出现异常:" + e.getMessage());
                e.printStackTrace();
            }
            return Hex.toHexString(arrayOfBytes);
        }
    
        public static String decrypt(String privateKeyHex, String cipherData) {
            return decrypt(getBCECPrivateKeyByPrivateKeyHex(privateKeyHex), cipherData, 1);
        }
    
        public static String decrypt(BCECPrivateKey privateKey, String cipherData, int modeType) {
            //解密模式
            SM2Engine.Mode mode = SM2Engine.Mode.C1C3C2;
            if (modeType != 1)
                mode = SM2Engine.Mode.C1C2C3;
           
            byte[] cipherDataByte = Hex.decode(cipherData);
            ECParameterSpec ecParameterSpec = privateKey.getParameters();
            ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                    ecParameterSpec.getG(), ecParameterSpec.getN());
            ECPrivateKeyParameters ecPrivateKeyParameters = new ECPrivateKeyParameters(privateKey.getD(),
                    ecDomainParameters);
    
            SM2Engine sm2Engine = new SM2Engine(mode);
            sm2Engine.init(false, ecPrivateKeyParameters);
            String result = null;
            try {
                byte[] arrayOfBytes = sm2Engine.processBlock(cipherDataByte, 0, cipherDataByte.length);
                result = new String(arrayOfBytes, "utf-8");
            } catch (Exception e) {
                System.out.println("SM2解密时出现异常" + e.getMessage());
            }
            return result;
        }
     
        private static X9ECParameters x9ECParameters = GMNamedCurves.getByName("sm2p256v1");
    
        private static ECParameterSpec ecDomainParameters = new ECParameterSpec(x9ECParameters.getCurve(), x9ECParameters.getG(), x9ECParameters.getN());
    
        public static BCECPublicKey getECPublicKeyByPublicKeyHex(String pubKeyHex) {
      
            if (pubKeyHex.length() > 128) {
                pubKeyHex = pubKeyHex.substring(pubKeyHex.length() - 128);
            }
            String stringX = pubKeyHex.substring(0, 64);
            String stringY = pubKeyHex.substring(stringX.length());
            BigInteger x = new BigInteger(stringX, 16);
            BigInteger y = new BigInteger(stringY, 16);
      
            ECPublicKeySpec ecPublicKeySpec = new ECPublicKeySpec(x9ECParameters.getCurve().createPoint(x, y), ecDomainParameters);
        
            return new BCECPublicKey("EC", ecPublicKeySpec, BouncyCastleProvider.CONFIGURATION);
        }
    
        public static BCECPrivateKey getBCECPrivateKeyByPrivateKeyHex(String privateKeyHex) {
            BigInteger d = new BigInteger(privateKeyHex, 16);
            ECPrivateKeySpec ecPrivateKeySpec = new ECPrivateKeySpec(d, ecDomainParameters);
            return new BCECPrivateKey("EC", ecPrivateKeySpec, BouncyCastleProvider.CONFIGURATION);
        }
    
        public static void main(String[] args) {
            String publicKeyHex = null;
            String privateKeyHex = null;
            KeyPair keyPair = createECKeyPair();
            PublicKey publicKey = keyPair.getPublic();
            if (publicKey instanceof BCECPublicKey) {
                //获取65字节非压缩缩的十六进制公钥串(0x04)
                publicKeyHex = Hex.toHexString(((BCECPublicKey) publicKey).getQ().getEncoded(false));
                System.out.println("SM2公钥：" + publicKeyHex);
            }
            PrivateKey privateKey = keyPair.getPrivate();
            if (privateKey instanceof BCECPrivateKey) {
                //获取32字节十六进制私钥串
                privateKeyHex = ((BCECPrivateKey) privateKey).getD().toString(16);
                System.out.println("SM2私钥：" + privateKeyHex);
            }
    
            /**
             * 公钥加密
             */
            String data = "=========需要加密的数据=========";
    
            //将十六进制公钥串转换为 BCECPublicKey 公钥对象
            String encryptData = encrypt(publicKeyHex, data);
            System.out.println("加密结果：" + encryptData);
    
            /**
             * 私钥解密
             */
            //将十六进制私钥串转换为 BCECPrivateKey 私钥对象
            data = decrypt(privateKeyHex, encryptData);
            System.out.println("解密结果：" + data);
        }
    }

#### pom依赖引入 ： ####

<dependency>
          <groupId>org.bouncycastle</groupId>
          <artifactId>bcprov-jdk15to18</artifactId>
          <version>1.68</version>
    </dependency>

[a5e40cd725a67474441df8c4af8f2f1d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/26/5886caa45ca248588381d7e01c549eb4.png