JsEncrypt.js前端加密，java后端解密

RSA与AES加密与解密

1.什么是对称加密

​ 对称加密算法是应用较早的加密算法，技术成熟。在对称加密算法中，数据发信方将明文（原始数据）和加密密钥（mi yao）一起经过特殊加密算法处理后，使其变成复杂的加密密文发送出去。收信方收到密文后，若想解读原文，则需要使用加密用过的密钥及相同算法的逆算法对密文进行解密，才能使其恢复成可读明文。在对称加密算法中，使用的密钥只有一个，发收信双方都使用这个密钥对数据进行加密和解密，这就要求解密方事先必须知道加密密钥。

​

1. 特点

对称加密算法的特点是算法公开、计算量小、加密速度快、加密效率高。

不足之处是，交易双方都使用同样钥匙，安全性得不到保证。此外，每对用户每次使用对称加密算法时，都需要使用其他人不知道的惟一钥匙，这会使得发收信双方所拥有的钥匙数量呈几何级数增长，密钥管理成为用户的负担。对称加密算法在分布式网络系统上使用较为困难，主要是因为密钥管理困难，使用成本较高。而与公开密钥加密算法比起来，对称加密算法能够提供加密和认证却缺乏了签名功能，使得使用范围有所缩小。在计算机专网系统中广泛使用的对称加密算法有DES和IDEA等。美国国家标准局倡导的AES即将作为新标准取代DES。

2.实现步骤

代码实现流程：

​

• 首先在页面加载完成时向后台发送ajax请求，后台随机生成一个16位的字符串key返回给前端
• 前端使用CryptoJS.js和后台生成的key对password进行加密
• 点击“登录”按钮后提交到后台，后台获取到加密后的密码进行解密后，把解密后的密码返回给前端展示出来。

导入依赖

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

后端controller

package com.sean.jsencrypt.controller;


import cn.hutool.core.util.RandomUtil;
import org.apache.commons.lang3.RandomUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import utils.AesUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;

@Controller
public class AesController {

    @GetMapping("/key")
    @ResponseBody
    private String create16String()
    {
        return RandomUtil.randomString(16);
    }

    @RequestMapping(value = "/login", method = RequestMethod.POST)
    @ResponseBody
    public Object login(HttpServletRequest request) throws Exception {
        String userName = request.getParameter("userName");
        String encryptedPassword = request.getParameter("password");
        String key = request.getParameter("key");

        String password = AesUtils.decrypt(encryptedPassword,key);

      return password;
    }
}

后端代码：AesUtils工具类

package utils;

import org.apache.commons.codec.binary.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class AesUtils {

        private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";

        public static String encrypt(String content, String key) {
            try {
                //获得密码的字节数组
                byte[] raw = key.getBytes();
                //根据密码生成AES密钥
                SecretKeySpec skey = new SecretKeySpec(raw, "AES");
                //根据指定算法ALGORITHM自成密码器
                Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
                //初始化密码器，第一个参数为加密(ENCRYPT_MODE)或者解密(DECRYPT_MODE)操作，第二个参数为生成的AES密钥
                cipher.init(Cipher.ENCRYPT_MODE, skey);
                //获取加密内容的字节数组(设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
                byte [] byte_content = content.getBytes("utf-8");
                //密码器加密数据
                byte [] encode_content = cipher.doFinal(byte_content);
                //将加密后的数据转换为字符串返回
                return Base64.encodeBase64String(encode_content);
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }

        public static String decrypt(String encryptStr, String decryptKey) {
            try {
                //获得密码的字节数组
                byte[] raw = decryptKey.getBytes();
                //根据密码生成AES密钥
                SecretKeySpec skey = new SecretKeySpec(raw, "AES");
                //根据指定算法ALGORITHM自成密码器
                Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
                //初始化密码器，第一个参数为加密(ENCRYPT_MODE)或者解密(DECRYPT_MODE)操作，第二个参数为生成的AES密钥
                cipher.init(Cipher.DECRYPT_MODE, skey);
                //把密文字符串转回密文字节数组
                byte [] encode_content = Base64.decodeBase64(encryptStr);
                //密码器解密数据
                byte [] byte_content = cipher.doFinal(encode_content);
                //将解密后的数据转换为字符串返回
                return new String(byte_content,"utf-8");
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
}

前端代码：

<!DOCTYPE html>
<html lang="en"
	  xmlns:th="http://www.w3.org/1999/xhtml"
>
<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<link rel="stylesheet" href="/css/bootstrap.min.css">

	<script src="/js/jquery-3.3.1.min.js" ></script>
	<script src="/js/bootstrap.min.js" ></script>
	<script src="https://cdn.bootcss.com/crypto-js/3.1.9-1/crypto-js.min.js"></script>


	<title>AES</title>

	<style>
		.bgColor {
			background-color: rgba(243, 66, 111, 0.15)
		}

		.divBorder {
			border: solid 1px rgba(12, 24, 255, 0.15);
			padding: 10px;
			margin-top: 10px;
			border-radius: 10px;
			text-align: center;
			vertical-align: middle;
		}

		.h4font {
			margin-top: 0px;
			font-family: 微软雅黑;
			font-weight: 500;
		}

		.center {
			padding: 20% 0;
		}

		.verifyInput {
			vertical-align: middle;
			font-size: 14px;
			font-weight: normal;
			line-height: 1;
			/*border:1px solid #999;*/
			float: left;
			 180px;
			height: 30px;

		}

		.verifyImage {
			vertical-align: middle;
			float: right;
			height: 30px;
		}

	</style>


</head>
<body>

<div class="container">
	<div class="row center">
		<div class="divBorder col-sm-offset-4 col-sm-4">
			<h3 class="panel panel-heading h4font">
				用户登录
			</h3>
			<h4 name="msg" th:text="${msg}"></h4>
			<input type="hidden" name="key" value="">
			<form class="form-horizontal" method="post">
				<div class="input-group">
					<span class="input-group-addon"><i class="glyphicon glyphicon-user" aria-hidden="true"></i></span>
					<input type="text" class="form-control" name="userName" placeholder="请输入用户名称"
						   th:value="${userName}"/>
				</div>
				<br>
				<div class="input-group">
					<span class="input-group-addon"><i class="glyphicon glyphicon-lock"></i></span>
					<input type="text" class="form-control" name="password" th:value="${password}"
						   placeholder="请输入密码"/>
				</div>
				<br/>

				<br>
				<input type="button" name="btnLogin" class="btn btn-lg btn-block btn-info" value="登 录">
			</form>
		</div>


	</div>

</div>
<script th:inline="javascript">
	$(function () {
		$.ajax({
			type: "get",
			url: "/key",
			success: function (result) {
				console.log(result);
				$('input[name="key"]').val(result)
			}
		})

		$('input[name="btnLogin"]').click(function () {
			var $key = $('input[name="key"]').val();
			var $userName = $('input[name="userName"]').val();
			var $password = $('input[name="password"]').val();

			var key = CryptoJS.enc.Utf8.parse($key);
			console.log("key:" + key + ",$key:" + $key);
			var password = CryptoJS.enc.Utf8.parse($password);
			var encrypted = CryptoJS.AES.encrypt(password, key, {mode: CryptoJS.mode.ECB, padding: CryptoJS.pad.Pkcs7});
			var encryptedPwd = encrypted.toString();

           console.log("encrypted:" + encrypted);
           console.log("encryptedPwd:" + encryptedPwd);

			var decrypt = CryptoJS.AES.decrypt(encryptedPwd, key, {
				mode: CryptoJS.mode.ECB,
				padding: CryptoJS.pad.Pkcs7
			});
			var testDecryptStr = CryptoJS.enc.Utf8.stringify(decrypt).toString();

           console.log("decrypt:" + decrypt);
           console.log("testDecryptStr:" + testDecryptStr);


			$.ajax({
				type: "post",
				url: "/login",
				data: {userName: $userName, password: encryptedPwd, key: $key },
				dataType: "json",
				success: function (result) {
					alert("后端解密后的密码："+result);
				}
			});

		})
	})
</script>
</body>
</html>

AES是通过后台随机生成的key进行密码的加密和解密的

2.什么是非对称加密

​ 非对称加密算法需要两个密钥：公开密钥（publickey:简称公钥）和私有密钥（privatekey:简称私钥）。公钥与私钥是一对，如果用公钥对数据进行加密，只有用对应的私钥才能解密。因为加密和解密使用的是两个不同的密钥，所以这种算法叫作非对称加密算法。

RAS则是一种非对称加密算法

代码实现流程：

​

实现步骤

生成公钥和私钥

首先对于非对称加密的话必须要有公钥和私钥，产生公钥和私钥的方式有很多种，我使用支付宝开放平台开发助手工具生成，也可以使用在线生成

把生成的公钥和私钥保存起来，前端页面用公钥加密，后端通过私钥解密

导入依赖

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

前端代码

<!DOCTYPE html >
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Login</title>
    <script src="https://blog.yoodb.com/app/default/js/jquery-2.1.4.min.js"></script>
    <script src="http://passport.cnblogs.com/scripts/jsencrypt.min.js"></script>
    <script type="text/javascript">

        $(function () {
            $("#btn").click(function () {
                let inputData = $('#data').val();
                let encrypt = new JSEncrypt();
                encrypt.setPublicKey("MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDXQHkn4dX3oUppqr2Vj7pBEDoe5Y+wJuTFqVImFU7xyDHCzwVY40q8/2OCmoMnrnjORL6Yh7UZl9GQ/FOvJHAnXrClU2mMRDzhTG9tw4mvsfDk/EHpJ+oCDUmlSqp1rG78mc89rjXqoaRzSsdqYB9bnpBHVjG8r1gmcRqKvCpuvQIDAQAB");
                let data = encrypt.encrypt(inputData);
                $("#encrypt").val(data);

                $.ajax({
                    type: "GET",
                    url: "/rsaDecrypt",
                    data:{
                        data:data
                    },
                    success: function (result) {
                        console.log(result);
                        $("#decrypt").val(result);
                    }
                })
            })
        });


    </script>
</head>
<body>
<div>
    <div>
        <label> 请输入要加密的字符串：</label>
        <input type="text" id="data" value="" />
        <button id = btn >发送</button>
    </div>

    <div style=" margin-top: 20px">
        <label>前端加密后：</label>
        <textarea id="encrypt"></textarea>
    </div>

    <div style=" margin-top: 20px">
        <label>后端解密后：</label>
        <textarea id="decrypt"></textarea>

    </div>
</div>
</body>
</html>

后端代码：RSAUtils工具类

package utils;

import org.apache.commons.codec.binary.Base64;
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;

/**
 * @author : sean
 * @version V1.0
 * @Project: jsencrypt
 * @Package utils
 * @date Date : 2021年09月23日 21:36
 * @Description: RSA加解密工具类，实现公钥加密私钥解密和私钥解密公钥解密
 */

public class RsaUtils {

        /**
         * 公钥加密私钥解密
         */
        private static void test1(RSAKeyPair keyPair, String source) throws Exception {
            System.out.println("***************** 公钥加密私钥解密开始 *****************");
            String text1 = encryptByPublicKey(keyPair.getPublicKey(), source);
            String text2 = decryptByPrivateKey(keyPair.getPrivateKey(), text1);
            System.out.println("加密前：" + source);
            System.out.println("加密后：" + text1);
            System.out.println("解密后：" + text2);
            if (source.equals(text2)) {
                System.out.println("解密字符串和原始字符串一致，解密成功");
            } else {
                System.out.println("解密字符串和原始字符串不一致，解密失败");
            }
            System.out.println("***************** 公钥加密私钥解密结束 *****************");
        }

        /**
         * 私钥加密公钥解密
         *
         * @throws Exception
         */
        private static void test2(RSAKeyPair keyPair, String source) throws Exception {
            System.out.println("***************** 私钥加密公钥解密开始 *****************");
            String text1 = encryptByPrivateKey(keyPair.getPrivateKey(), source);
            String text2 = decryptByPublicKey(keyPair.getPublicKey(), text1);
            System.out.println("加密前：" + source);
            System.out.println("加密后：" + text1);
            System.out.println("解密后：" + text2);
            if (source.equals(text2)) {
                System.out.println("解密字符串和原始字符串一致，解密成功");
            } else {
                System.out.println("解密字符串和原始字符串不一致，解密失败");
            }
            System.out.println("***************** 私钥加密公钥解密结束 *****************");
        }

        /**
         * 公钥解密
         *
         * @param publicKeyText
         * @param text
         * @return
         * @throws Exception
         */
        public static String decryptByPublicKey(String publicKeyText, String text) throws Exception {
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            byte[] result = cipher.doFinal(Base64.decodeBase64(text));
            return new String(result);
        }

        /**
         * 私钥加密
         *
         * @param privateKeyText
         * @param text
         * @return
         * @throws Exception
         */
        public static String encryptByPrivateKey(String privateKeyText, String text) throws Exception {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            byte[] result = cipher.doFinal(text.getBytes());
            return Base64.encodeBase64String(result);
        }

        /**
         * 私钥解密
         *
         * @param privateKeyText
         * @param text
         * @return
         * @throws Exception
         */
        public static String decryptByPrivateKey(String privateKeyText, String text) throws Exception {
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec5 = new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKeyText));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec5);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] result = cipher.doFinal(Base64.decodeBase64(text));
            return new String(result);
        }

        /**
         * 公钥加密
         *
         * @param publicKeyText
         * @param text
         * @return
         */
        public static String encryptByPublicKey(String publicKeyText, String text) throws Exception {
            X509EncodedKeySpec x509EncodedKeySpec2 = new X509EncodedKeySpec(Base64.decodeBase64(publicKeyText));
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec2);
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            byte[] result = cipher.doFinal(text.getBytes());
            return Base64.encodeBase64String(result);
        }

        /**
         * 构建RSA密钥对
         *
         * @return
         * @throws NoSuchAlgorithmException
         */
        public static RSAKeyPair generateKeyPair() throws NoSuchAlgorithmException {
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
            keyPairGenerator.initialize(1024);
            KeyPair keyPair = keyPairGenerator.generateKeyPair();
            RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
            String publicKeyString = Base64.encodeBase64String(rsaPublicKey.getEncoded());
            String privateKeyString = Base64.encodeBase64String(rsaPrivateKey.getEncoded());
            RSAKeyPair rsaKeyPair = new RSAKeyPair(publicKeyString, privateKeyString);
            return rsaKeyPair;
        }


        /**
         * RSA密钥对对象
         */
        public static class RSAKeyPair {

            private String publicKey;
            private String privateKey;

            public RSAKeyPair(String publicKey, String privateKey) {
                this.publicKey = publicKey;
                this.privateKey = privateKey;
            }

            public String getPublicKey() {
                return publicKey;
            }

            public String getPrivateKey() {
                return privateKey;
            }

        }

}

后端代码：RSAController

@RestController
public class RsaController {
    private static final String privateKey = "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";

    @GetMapping("/rsaDecrypt")
    public String DecryptAction(String data) throws Exception {
        System.out.println(data);
        String decrypt = RsaUtils.decryptByPrivateKey(privateKey, data);
        return decrypt;
    }
}