国密SM2 后端Hutool+前端sm-crypto

前言

在网上找了很多文章，都只是单独说了用后端加解密及前端加解密，很少把两个结合起来一起说的文章，本文分享两者结合起来的用法和踩坑。

准备工作

前端项目引入第三方包

npm install --save sm-crypto

后端项目引入工具类

    cn.hutool
    hutool-all
    5.8.16


  org.bouncycastle
  bcprov-jdk15to18
  1.69

生成密钥

使用工具类生成两套公私钥: 服务端公私钥、客户端公私钥

前端拿服务端公钥+客户端私钥

后端拿客户端公钥+服务端私钥

本文仅做演示，如何安全存储密钥请自行研究。

	import cn.hutool.core.util.HexUtil;
	import cn.hutool.crypto.BCUtil;
	import cn.hutool.crypto.SmUtil;
	import cn.hutool.crypto.asymmetric.SM2;
	import org.bouncycastle.crypto.engines.SM2Engine;
	import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
				
	//创建sm2 对象
	SM2 sm = SmUtil.sm2();
		        
	// sm2的加解密时有两种方式即 C1C2C3、 C1C3C2，
	sm.setMode(SM2Engine.Mode.C1C3C2);
		        
	// 生成私钥
	String privateKey = HexUtil.encodeHexStr(sm.getPrivateKey().getEncoded());
	log.info("私钥: {}", privateKey);
		        
	// 生成公钥
	String publicKey = HexUtil.encodeHexStr(sm.getPublicKey().getEncoded());
	log.info("公钥: {}", publicKey);
	
	 // 生成私钥 D，以D值做为js端的解密私钥
     String privateKeyD = HexUtil.encodeHexStr(BCUtil.encodeECPrivateKey(sm.getPrivateKey()));
     log.info("私钥D: {}", privateKeyD);
     	
	// 生成公钥 Q，以Q值做为js端的加密公钥
	String publicKeyQ = HexUtil.encodeHexStr(((BCECPublicKey) sm.getPublicKey()).getQ().getEncoded(false));
	log.info("公钥Q: {}", publicKeyQ);

	私 钥: 308193020100301306072a8648ce3d020106082a811ccf5501822d047930770201010420b1933b8a0c16c1bcf64dcbcc2cb822c27452dfb8a19b6167e5ee9bec963b8171a00a06082a811ccf5501822da14403420004d6fd83141fe38cee09f8f4e20a72d3ba056dcfeeda4238dc671a1f11e811293c10b8537ea0adb4b9ad1fa37d147b65c451fe4ab51054d71c810cc0e84cd8232d
	公 钥: 3059301306072a8648ce3d020106082a811ccf5501822d03420004d6fd83141fe38cee09f8f4e20a72d3ba056dcfeeda4238dc671a1f11e811293c10b8537ea0adb4b9ad1fa37d147b65c451fe4ab51054d71c810cc0e84cd8232d
	私钥D: 00b1933b8a0c16c1bcf64dcbcc2cb822c27452dfb8a19b6167e5ee9bec963b8171
	公钥Q: 04d6fd83141fe38cee09f8f4e20a72d3ba056dcfeeda4238dc671a1f11e811293c10b8537ea0adb4b9ad1fa37d147b65c451fe4ab51054d71c810cc0e84cd8232d

上面密钥仅供参考

加密及解密

1.前端加密+后端解密

在需要加解密的js文件中引入sm2方法

const sm2 = require('sm-crypto').sm2
// 1 - C1C3C2，0 - C1C2C3，默认为1
const cipherMode = 1 
//服务端公钥 Q
const publicKeyQ ="服务端公钥 Q";
//要加密的报文
const body={"age":10,"name":"张三"}
 // 加密
let encryStr=sm2.doEncrypt(JSON.stringify(body), publicKeyQ, cipherMode);

 // 加密结果
encryStr: aaaba1cea1af9a9c621d75bacc7434e1eea713861885a28ab8b3a5ebc911bf971c76af94acff2ab0647b8e157e9ccb6f78e85d5173120fbb11f9be610c0194c3c7d97b069478c4f07d06982b4c691d530bb817f490f531b271ee8d52bb9babbe8305ff92782f4fe263a6ea63d010c4bb682241aff20b5c11442a

注意：通过前端加密的密文没有04前缀，所以如果我们想要在后端解密需要手动加上

把密文传给后端进行解密

	import cn.hutool.core.util.StrUtil;
	
	//服务端私钥
  	String privateKey = "服务端私钥";
  	
  	//后端解密时,公钥可以不填
    String publicKey = "";
    
    //手动加上前缀04
	String encryStr = "04" + "aaaba1cea1af9a9c621d75bacc7434e1eea713861885a28ab8b3a5ebc911bf971c76af94acff2ab0647b8e157e9ccb6f78e85d5173120fbb11f9be610c0194c3c7d97b069478c4f07d06982b4c691d530bb817f490f531b271ee8d52bb9babbe8305ff92782f4fe263a6ea63d010c4bb682241aff20b5c11442a";
	SM2 sm2 = SmUtil.sm2(HexUtil.decodeHex(privateKey), null);
	log.info("密文: {}", encryStr);
	byte[] decrypt = sm2.decrypt(encryStr, KeyType.PrivateKey);
	log.info("解密结果: {}", StrUtil.utf8Str(decrypt));

密文: 04aaaba1cea1af9a9c621d75bacc7434e1eea713861885a28ab8b3a5ebc911bf971c76af94acff2ab0647b8e157e9ccb6f78e85d5173120fbb11f9be610c0194c3c7d97b069478c4f07d06982b4c691d530bb817f490f531b271ee8d52bb9babbe8305ff92782f4fe263a6ea63d010c4bb682241aff20b5c11442a
解密结果: {"age":10,"name":"张三"}

2.后端加密+前端解密

	//后端加密时,可以不填私钥。 客户端公钥
	SM2 sm2 = SmUtil.sm2(null, HexUtil.decodeHex(publicKey));
	String str = "Hello World";
	byte[] encrypt = sm2.encrypt(str, KeyType.PublicKey);
	String encryStr = HexUtil.encodeHexStr(encrypt);
	log.info("密文: {}", encryStr);

	密文: 046415900ab4af09490d257cdd5aee2d0710b1e222d4386124d6e70f4e39468d2e68d7eb9830db46804b472747e42819bdd56312982da1f765a963cd4c7c51795bd8c3faa220547033740dcb2f91b17039a05c9c6081bbf9c756b90f9a09cfa8cb39e0853766394661b265c60b

注意：后端密文前缀存在04，前端在解密时会在首部自动补充 04，所以我们需截取后再传入。

  const sm2 = require('sm-crypto').sm2
  // 1 - C1C3C2，0 - C1C2C3，默认为1
  const cipherMode = 1 
  
	//客户端私钥 D
  let privateKeyD="客户端私钥 D"
  
  //去掉04前缀后的密文
  let encryStr ="6415900ab4af09490d257cdd5aee2d0710b1e222d4386124d6e70f4e39468d2e68d7eb9830db46804b472747e42819bdd56312982da1f765a963cd4c7c51795bd8c3faa220547033740dcb2f91b17039a05c9c6081bbf9c756b90f9a09cfa8cb39e0853766394661b265c60b"
  const str = sm2.doDecrypt(encryStr , privateKeyD, cipherMode);
  console.log("解密报文:",str);
  

解密报文: Hello World

签名及验签

1.后端加签+前端验签

  // 服务端私钥 ,签名时可以不填公钥
  SM2 sm2 = SmUtil.sm2(HexUtil.decodeHex(privateKey),null);
  
  //要签名的明文数据
  String str = "Hello World";
  //把明文字符串转为十六进制字符串
  String sign = sm2.signHex(HexUtil.encodeHexStr(str));
  log.info("签名:{}", sign);

签名:304502207b8a07c36a97c34278bf4352af13f4a1022f79816820c52a1a23d7499e24a609022100dcf53edf3f2d7f648fea027cacce90f6d101923b1215b2cb9aa6811064ed6cdd

前端接受密文和签名

/**
 * msg  明文数据即解密后数据
 * sigValueHex 后端传过来的签名(不需要进行任何处理)
 * publicKeyQ 服务端公钥 Q
 * 最后的json对象必传,否则验签失败
 */
sm2.doVerifySignature(msg, sigValueHex, publicKeyQ ,{der: true,hash: true,}) // 验签结果
const sm2 = require('sm-crypto').sm2
let signResult = sm2.doVerifySignature(
      "Hello World", "304502207b8a07c36a97c34278bf4352af13f4a1022f79816820c52a1a23d7499e24a609022100dcf53edf3f2d7f648fea027cacce90f6d101923b1215b2cb9aa6811064ed6cdd",
      publicKeyQ,
      { hash: true, der: true }
    );
console.log("验签结果:", signResult);

验签结果: true

2.前端加签+后端验签

/**
 * msg  明文数据
 * privateKeyD 客户端私钥 D
 * 最后的json对象必传,否则验签失败
 */
sm2.doSignature(msg, privateKeyD,{der: true,hash: true,}) // 签名
let sign = sm2.doSignature("Hello World",privateKeyD,{der:true,hash:true,}
);
console.log("签名:", sign);

签名:30450220740a651a3f44b7647c884540b19571131da65c88e2750fd8c780d1062af16f9b022100f320694a65f1e85b0320789b9bf9b78c4cfc94f6bc6562e61072389f944ca3de

// 客户端公钥 ,验签时可以不填私钥
SM2 sm2 = SmUtil.sm2(null, HexUtil.decodeHex(publicKey));
//解密后的报文
String str = "Hello World";
String sign = "30450220740a651a3f44b7647c884540b19571131da65c88e2750fd8c780d1062af16f9b022100f320694a65f1e85b0320789b9bf9b78c4cfc94f6bc6562e61072389f944ca3de";
boolean signResult = sm2.verifyHex(HexUtil.encodeHexStr(str), sign);
log.info("验签结果:{}",signResult);

验签结果: true