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:


















