加密方式之SM2

àì夳堔傛蜴生んèń 2021-09-28 19:54 335阅读 0赞

有一项需求，为了相对保证安全，需要敏感字符添加加密国密方式，于是想到了SM2，话不多说，上代码。

## 一、前端js代码。 ##

开始也是找了好久的m2的前端js加密方式，很少，这里找到一个大哥的，贴上连接[https://jm1999.iteye.com/blog/2408361][https_jm1999.iteye.com_blog_2408361]

在这位大哥的基础上做了一些修改，放到自己的sm2Utils.js中了

说明：最后两个方法还没有测试，调用的是function sm2Encrypt(data, publickey, cipherMode) \{ 。。。\} 参数说明，data是你要加密的东西，比如密码什么的，publickey是你经过请求后端方法，生成的公钥，私钥是留在后端进行解密用的。cipherMode是选择加密方式，\[加密模式 C1C3C2:1, C1C2C3:0\]

## 二、SM2Utils工具类 ##

package com.simp.action.sm.sm2;
    
    import java.io.IOException;
    import java.math.BigInteger;
    import java.util.HashMap;
    import java.util.Map;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpSession;
    import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
    import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
    import org.bouncycastle.crypto.params.ECPublicKeyParameters;
    import org.bouncycastle.math.ec.ECPoint;
    import com.simp.action.RTUser;
    import com.simp.action.security.SecurePasswdLib;
    import com.simp.action.sm.utils.Util;
    
    public class SM2Utils {
    	
    	public static final String RSA_PAIR_PUBLIC_KEY = "public";
    	public static final String RSA_PAIR_PRICATE_KEY = "private";
    	
    	//生成随机秘钥对
    	public static void generateKeyPair(){
    		SM2 sm2 = SM2.Instance();
    		AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
    		ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
    		ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
    		BigInteger privateKey = ecpriv.getD();
    		ECPoint publicKey = ecpub.getQ();
    		
    		System.out.println("公钥: " + Util.byteToHex(publicKey.getEncoded()));
    		System.out.println("私钥: " + Util.byteToHex(privateKey.toByteArray()));
    	}
    	
    	//数据加密
    	public static String encrypt(byte[] publicKey, byte[] data) throws IOException {
    		if (publicKey == null || publicKey.length == 0) {
    			return null;
    		}
    		
    		if (data == null || data.length == 0) {
    			return null;
    		}
    		
    		byte[] source = new byte[data.length];
    		System.arraycopy(data, 0, source, 0, data.length);
    		
    		Cipher cipher = new Cipher();
    		SM2 sm2 = SM2.Instance();
    		ECPoint userKey = sm2.ecc_curve.decodePoint(publicKey);
    		
    		ECPoint c1 = cipher.Init_enc(sm2, userKey);
    		cipher.Encrypt(source);
    		byte[] c3 = new byte[32];
    		cipher.Dofinal(c3);
    		
    //		System.out.println("C1 " + Util.byteToHex(c1.getEncoded()));
    //		System.out.println("C2 " + Util.byteToHex(source));
    //		System.out.println("C3 " + Util.byteToHex(c3));
    		//C1 C2 C3拼装成加密字串
    		return Util.byteToHex(c1.getEncoded()) + Util.byteToHex(source) + Util.byteToHex(c3);
    		
    	}
    	
    	//数据解密
    	public static byte[] decrypt(byte[] privateKey, byte[] encryptedData) throws IOException {
    		if (privateKey == null || privateKey.length == 0) {
    			return null;
    		}
    		
    		if (encryptedData == null || encryptedData.length == 0) {
    			return null;
    		}
    		//加密字节数组转换为十六进制的字符串 长度变为encryptedData.length * 2
    		String data = Util.byteToHex(encryptedData);
    		/***分解加密字串
    		 * （C1 = C1标志位2位 + C1实体部分128位 = 130）
    		 * （C3 = C3实体部分64位  = 64）
    		 * （C2 = encryptedData.length * 2 - C1长度  - C2长度）
    		 */
    		byte[] c1Bytes = Util.hexToByte(data.substring(0,130));
    		int c2Len = encryptedData.length - 97;
    		byte[] c2 = Util.hexToByte(data.substring(130,130 + 2 * c2Len));
    		byte[] c3 = Util.hexToByte(data.substring(130 + 2 * c2Len,194 + 2 * c2Len));
    		
    		SM2 sm2 = SM2.Instance();
    		BigInteger userD = new BigInteger(1, privateKey);
    		
    		//通过C1实体字节来生成ECPoint
    		ECPoint c1 = sm2.ecc_curve.decodePoint(c1Bytes);
    		Cipher cipher = new Cipher();
    		cipher.Init_dec(userD, c1);
    		cipher.Decrypt(c2);
    		cipher.Dofinal(c3);
    		
    		//返回解密结果
    		return c2;
    	}
    	
    	
    	//生成随机秘钥对
    	public static HashMap<String, Object> getKeys(){
    		HashMap<String, Object> map = new HashMap<String, Object>();
    		SM2 sm2 = SM2.Instance();
    		AsymmetricCipherKeyPair key = sm2.ecc_key_pair_generator.generateKeyPair();
    		ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) key.getPrivate();
    		ECPublicKeyParameters ecpub = (ECPublicKeyParameters) key.getPublic();
    //		System.out.println("公钥: " + Util.byteToHex(publicKey.getEncoded()));
    //		System.out.println("私钥: " + Util.byteToHex(privateKey.toByteArray()));
    		map.put(RSA_PAIR_PUBLIC_KEY, ecpub);
    		map.put(RSA_PAIR_PRICATE_KEY, ecpriv);
    		return map;
    	}
    	
    	
    	/**
    	 * 2019/5/29 machao ==添加==
    	 * @param request
    	 * @param userPassword
    	 * @return
    	 */
    	public static String getRSAText(HttpServletRequest request, String userPassword) {
    		ECPrivateKeyParameters prkey = RTUser.get_from_session(request).getPrivateKey();
    		return getRSAText(prkey,userPassword);
    	}
    	
    	/**
    	 * 2019/5/29 machao ==添加==
    	 * @param prkey
    	 * @param ens
    	 * @return
    	 */
    	public static String getRSAText(ECPrivateKeyParameters prkey, String ens) {
    		BigInteger privateKey = prkey.getD();
    		String priExponent =  new String(Util.byteToHex(privateKey.toByteArray()));
    		try {
    			byte[] prikey = Util.hexToByte(priExponent);
    			byte[] enDate = Util.hexToByte(ens);
    			return new String(SM2Utils.decrypt(prikey,enDate));
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return "";
    	}
    	
    	public static void main(String[] args) throws Exception {
    		//生成密钥对
    		generateKeyPair();
    		
    		String plainText = "ererfeiisgod";
    		byte[] sourceData = plainText.getBytes();
    		
    		//下面的秘钥可以使用generateKeyPair()生成的秘钥内容
    		// 国密规范正式私钥
    //		String prik = "3690655E33D5EA3D9A4AE1A1ADD766FDEA045CDEAA43A9206FB8C430CEFE0D94";
    		// 国密规范正式公钥
    //		String pubk = "04F6E0C3345AE42B51E06BF50B98834988D54EBC7460FE135A48171BC0629EAE205EEDE253A530608178A98F1E19BB737302813BA39ED3FA3C51639D7A20C7391A";
    		Map<String, Object> keyMap = SM2Utils.getKeys();
    		ECPublicKeyParameters publicKey = (ECPublicKeyParameters) keyMap.get(SM2Utils.RSA_PAIR_PUBLIC_KEY);
    		ECPrivateKeyParameters privateKey = (ECPrivateKeyParameters) keyMap.get(SM2Utils.RSA_PAIR_PRICATE_KEY);
    		String modulus = publicKey.getParameters().getN().toString(16);
    		String pubk = publicKey.getQ().getEncoded().toString();
    		String prik = privateKey.getD().toString();
    		System.out.println(modulus);
    		
    		System.out.println("加密: ");
    		String cipherText = SM2Utils.encrypt(Util.hexToByte(pubk), sourceData);
    		System.out.println(cipherText);
    		System.out.println("解密: ");
    		plainText = new String(SM2Utils.decrypt(Util.hexToByte(prik), Util.hexToByte(cipherText)));
    		System.out.println(plainText);
    		
    	}
    	
    }

说明：这个工具类不算完善，待测试

## 三、调用 ##

一前端请求action的方法，

private void noLoginGetSPL(HttpServletRequest request, HttpServletResponse response) throws NoSuchAlgorithmException, IOException {
    		Map<String, Object> keyMap = SM2Utils.getKeys();
    		ECPublicKeyParameters ecpub = (ECPublicKeyParameters) keyMap.get(SM2Utils.RSA_PAIR_PUBLIC_KEY);
    		ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters) keyMap.get(SM2Utils.RSA_PAIR_PRICATE_KEY);
    		BigInteger privateKey = ecpriv.getD();
    		ECPoint publicKey = ecpub.getQ();
    		HttpSession session = request.getSession();
    		String modulus = ecpub.getParameters().getN().toString(16);
    		session.setAttribute(SPL_MODULUS_KEY,modulus);
    		session.setAttribute(SPL_PRIEXPONENT_KEY, new String(Util.byteToHex(privateKey.toByteArray())));
    		String pubL = modulus + ";" + new String(Util.byteToHex(publicKey.getEncoded()));
    		response.getWriter().write(pubL);
    		response.getWriter().flush();
    	}

二、前端进行加密

三、后端收到加密后的东西，在调用sm2工具解密

================================end==========================================

[https_jm1999.iteye.com_blog_2408361]: https://jm1999.iteye.com/blog/2408361