[网络协议]RSA前端加密后端解密

前面说过接口数据在后端如何使用RSA加解密
这里遇到了使用RSA前端加密后端解密的需求。
实现方式如下：

1、后端的RSA工具

package com.ieslab.interactivequery.util;

import org.springframework.stereotype.Service;

import javax.crypto.Cipher;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

/**
 * @description: RSA加密工具
 * @author: yiwenli
 * @create: 2021-04-29 09:52
 **/
@Service
public class RSAUtil {

    // 私钥字符串
    private static String privateKeyStr;

    // 公钥字符串
    private static String publicKeyStr;

    public static String getPublicKeyStr() {
        return publicKeyStr;
    }

    /**
     * 获取公钥私钥
     */
    public static void initKey() {
        try {
            Base64.Encoder encoder = Base64.getEncoder();
            // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
            KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
            // 初始化密钥对生成器，密钥大小为96-1024位
            keyPairGen.initialize(1024, new SecureRandom());
            // 生成一个密钥对，保存在keyPair中
            KeyPair keyPair = keyPairGen.generateKeyPair();
            // 得到私钥
            RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
            // 得到公钥
            RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

            privateKeyStr = new String(encoder.encode((privateKey.getEncoded())));
            publicKeyStr = new String(encoder.encode(publicKey.getEncoded()));
        } catch (NoSuchAlgorithmException e) {

            e.printStackTrace();
        }

    }

    /**
     * RSA公钥加密
     *
     * @param str       加密字符串
     * @param publicKey 公钥
     */
    public static String encrypt(String str, String publicKey) {
        try {
            Base64.Decoder decoder = Base64.getDecoder();
            Base64.Encoder encoder = Base64.getEncoder();
            //base64编码的公钥
            byte[] decoded = decoder.decode(publicKey);
            RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
            //RSA加密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, pubKey);
            String outStr = encoder.encodeToString(cipher.doFinal(str.getBytes("UTF-8")));
            return outStr;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * RSA私钥解密
     *
     * @param str        加密字符串
     */
    public static String decrypt(String str) {
        try {
            Base64.Decoder decoder = Base64.getDecoder();
            //64位解码加密后的字符串
            byte[] inputByte = decoder.decode(str.getBytes("UTF-8"));
            //base64编码的私钥
            byte[] decoded = decoder.decode(privateKeyStr);
            RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
            //RSA解密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, priKey);
            String outStr = new String(cipher.doFinal(inputByte));
            return outStr;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}

2、项目启动后调用初始化公私钥方法

public class XXXApplication {

    public static void main(String[] args) {
        SpringApplication springApplication = new SpringApplication(XXXApplication .class);
        springApplication.run(args);

        RSAUtil.initKey();
    }

3、写一个给前台提供公钥的接口

/**
     * 获取数据加密公钥
     */
    @RequestMapping(value = "/getPublicKeyStr", produces = "application/json;charset=utf-8")
    public String getPublicKeyStr() {
        return Result.success(RSAUtil.getPublicKeyStr()).toJsonString();
    }

4、前端html引用jsencrypt工具包

<script src="/XXX/plugins/jsencrypt.min.js"></script>

5、JS中创建JSEncrypt对象并设置公钥值

new Vue({
	el: "#app",
    data() {
    	encrypt: new JSEncrypt(), // JSEncrypt对象
    },
    created() {
        this.getPublicKey();
    },
     methods: {
        /**
         * 获取数据加密公钥给encrypt赋值
         */
        getPublicKey() {
            utils.getData(`${config.baseUrl}/transManage/getPublicKeyStr`, {}).then(res => {
                this.encrypt.setPublicKey(res);
            }).catch(e => {
            })
        },
    },
})

6、前端加密时使用

xxx = this.encrypt.encrypt(xxx)

7、后端解析

RSAUtil.decrypt(xxx)