Java实现前端jsencrypt.js加密后端解密的示例代码
1.什么是RSA
计算机中常用的加密技术分为两类：对称加密、非对称加密。
RSA属于非对称加密。加密、解密过程使用不同的秘钥，分为公钥、私钥。公钥可以公开，私钥不可以。
对称加密：加密和解密使用相同的的秘钥Key，这个Key需要在网络上传输，不安全，因此需要非对称加密。
2.RSA算法
2.1 生成公钥和私钥
（1）随意选择两个大的素数P和Q，P不等于Q；
（2）令 N = P × Q 、 T = ( P − 1 ) × ( Q − 1 ) N = P \times Q、T = (P - 1) \times (Q - 1) N=P×Q、T=(P−1)×(Q−1)；
（3）选择一个整数E作为秘钥，需要满足：GCd(E, T)=1 && E<T；
（4）根据 ( D × E ) m o d T = 1 (D \times E) \ mod \ T = 1 (D×E) mod T=1，计算出D，作为另一个秘钥；
（5）使用PK=(N、E)作为公钥、SK=(N, D)作为私钥（当然可以反过来）。
2.2 使用公钥加密信息
使用PK=(N、E)公钥加密信息。
若明文为M，则密文C可以按照如下计算得到（要求M<N）
2.3 使用私钥解密信息
使用SK=(N, D)私钥解密信息。
如密文为C，则明文M可以按照如下计算得到：
4.RSA的应用：数字签名
数字签名是实现安全交易的核心技术之一，实现基础是RSA加密技术。
数字签名类似于我们生活中的手写签名，必须保证签名的人事后不能抵赖，同时不能让别人伪造我们的签名。因此数字签名需要保证：
（1）发送者事后不能抵赖对报文的签名；
（2）接受者不能伪造对报文的签名。
如果A向B发送报文M，A手中有私钥，公钥是公开的，A给M使用私钥进行加密再发给B即可。
这样即可保证上述两点：
（1）因为只有A可以对M使用私钥进行加密，A不能抵赖；
（2）B用公钥可以得到原始信息M，如果伪造成M’，则A可以证明其伪造了信息。
在解密之前我们先进行验签操作,如果验签失败,则认为内容是伪造,不进行解密。
5.RSA的安全性
RSA算法的安全性依赖于大数分解。因此为了保证安全性，需要使得P、Q非常大。
因为数据很大，又牵涉到幂次运算，因此计算量很大。
6.为什么要写这文章
因为我想做一个数据加密，就开始了解Rsa加密算法，实现一个前端加密，后端解密的一个过程,然后我也不想重复造轮子，就上百度搜索，发现好多文章都是抄来抄去去的根本不合适。所以只好自己写了一个记录，以便到时候要用的时候再看，前端使用jsencrypt.js进行加密，然后在使用的时候我发现这个内容过长无法加密，然后又找了个扩展的，可以使用长内容加密，但是到后台解密的时候出问题了，无法解密出正确内容，我只好换回原理的版本，然后自己重写了两个方法来进行扩展，实现长内容加密。这个改进后的方法按理论可以进行很大文本文本加密传输，但是具体能承载多长我没有测试过，尽量不要使用rsa加密来加密比较长的文本，因为rsa加密是比较麻烦的，复杂度比较高，在加密之前也要考虑那些数据需要加密，那些数据不需要加密，不要通通都加密，这样解密的时候会浪费许多时间，增加服务器的压力，访问时间过长。
因为Rsa加密算法还是稍微复杂，我就不过的阐述，直接看源码吧，先复制过去能跑，然后再自己上网搜索，相关内容进行脑补，这个改进估计会存在问题，因为加密的长度限制117，和每次加密后的内容长度172 ，我不太清楚是不是固定的，我尝试了很多次都没有出现问题，等出现问题再解决吧。
7.前端代码
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<script src="../js/jsencrypt.js" type="text/javascript" charset="utf-8"></script>
<script src="../js/Jquery1.42.min.js" type="text/javascript" charset="utf-8"></script>
<body>
<script type="text/javascript">
let RsaUtil = {
publicKey: '',
privateKey: '',
rsaEncrypt: {},
// 长文本加密
encryptLong: function(content) {
let encryptionSectionSize = 117;
content = encodeURIComponent(content);
let ciphertext = '';
if (content && content.length > encryptionSectionSize) {
let paragraphic = content.length / encryptionSectionSize;
let isIntger = (paragraphic | 0) === paragraphic;
let encryptionCountet = parseInt(paragraphic);
if (isIntger) {
for (let i = 0; i < encryptionCountet; i++) {
ciphertext += this.rsaEncrypt.encrypt(content.substring(i * encryptionSectionSize, (i * encryptionSectionSize) +
encryptionSectionSize));
}
} else {
let lastContentLength = content.length % encryptionSectionSize;
for (let i = 0; i < encryptionCountet; i++) {
ciphertext += this.rsaEncrypt.encrypt(content.substring(i * encryptionSectionSize, (i * encryptionSectionSize) +
encryptionSectionSize));
}
ciphertext += this.rsaEncrypt.encrypt(content.substring(encryptionCountet * encryptionSectionSize,
encryptionCountet *
encryptionSectionSize + lastContentLength));
}
} else {
ciphertext = this.rsaEncrypt.encrypt(content);
}
return ciphertext;
},
// 长文本解密
decryptLong: function(content) {
let decodeSectionSize = 172;
let decodeText = '';
let isFinish = false;
if (content && content.length > decodeSectionSize) {
let paragraphic = content.length / decodeSectionSize;
let isIntger = (paragraphic | 0) === paragraphic;
let encryptionCountet = parseInt(paragraphic);
if (isIntger) {
for (let i = 0; i < encryptionCountet; i++) {
decodeText += this.rsaEncrypt.decrypt(content.substring(i * decodeSectionSize, (i * decodeSectionSize) +
decodeSectionSize));
isFinish = decodeText.indexOf('false') !== -1;
if (isFinish) {
return isFinish;
}
}
} else {
let lastContentLength = content.length % decodeSectionSize;
for (let i = 0; i < encryptionCountet; i++) {
decodeText += this.rsaEncrypt.encrypt(content.substring(i * decodeSectionSize, (i * decodeSectionSize) +
decodeSectionSize));
isFinish = decodeText.indexOf('false') !== -1;
if (isFinish) {
return isFinish;
}
}
decodeText += this.rsaEncrypt.encrypt(content.substring(encryptionCountet * decodeSectionSize,
encryptionCountet *
decodeSectionSize + lastContentLength));
}
} else {
decodeText = this.rsaEncrypt.decrypt(content);
}
return decodeURIComponent(decodeText);
},
// 小于117长度的字符串加密
encrypt: function(content) {
return this.encrypt(content);
},
// 小于117长度的字符串解密
decrypt: function(content) {
return this.decrypt(content);
},
// 初始化RsaUtil工具对象
init: function(publicKey, privateKey) {
if (!publicKey) {
throw new Error('publicKey cant't null');
}
let rsaEncrypt = new JSEncrypt();
rsaEncrypt.setPublicKey(publicKey);
if (privateKey) {
rsaEncrypt.setPrivateKey(privateKey);
}
this.publicKey = publicKey;
this.privateKey = privateKey;
this.rsaEncrypt = rsaEncrypt;
}
}
async function getPublicKey() {
return new Promise((resolve, reject) => {
$.ajax({
url: "Http://localhost:8080/rsa/getPublicKey",
type: "GET",
data: {},
success: function(data, textStatus) {
if (data && data.code === 200 && data.content.length > 0) {
resolve(data.content);
} else {
reject(false);
}
},
error: function(error) {
reject(false);
}
});
})
}
async function privateKeyDecode(content) {
return new Promise((resolve, reject) => {
$.ajax({
url: "http://localhost:8080/rsa/privateKeyDecode",
type: "POST",
contentType: "application/JSON",
dataType: "json",
data: JSON.stringify({
content
}),
success: function(data, textStatus) {
if (data && data.code === 200 && data.content.length > 0) {
resolve(data.content);
} else {
resolve(false);
}
},
error: function(error) {
resolve(false);
}
});
})
}
let userInfo = {
id: '1564868915154190336',
nickName: '小明',
sex: '男',
email: '1482334546@qq.com',
userType: '1',
userName: 'admin',
passWord: 'admin666?',
createTime: '2022-08-31 14:55',
valid: '1',
isDelete: '0',
headImg: 'https://profile.csdnimg.cn/7/3/0/2_m0_46188681',
}
let userInfoStr = JSON.stringify(userInfo)
async function dataEncryption() {
let publicKey = await getPublicKey();
RsaUtil.init(publicKey);
console.log("后台获取到的公钥:" + publicKey)
let ciphertext = RsaUtil.encryptLong(userInfoStr);
console.log("使用后台公钥加密后的文本:" + ciphertext);
let decodeResult = await privateKeyDecode(ciphertext);
console.log("使用后台私钥解密后的文本:" + decodeResult)
console.log("是否解密成功",decodeResult === userInfoStr)
}
dataEncryption();
</script>
</body>
</html>8.后端代码
RsaUtilClient配合 jsencrypt.js 解密的工具类
import org.springframework.util.Base64Utils;
import javax.crypto.Cipher;
import java.net.URLDecoder;
import java.security.*;
import java.security.spec.*;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class RsaUtilClient {
public static final String KEY_ALGoRITHM = "RSA";
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
private static final String PUBLIC_KEY = "RSAPublicKey";
private static final String PRIVATE_KEY = "RSAPrivateKey";
private static volatile ConcurrentHashMap<String,Key> KEY_MAP = new ConcurrentHashMap<>(2);
public static byte[] decryptBASE64(String content) {
return org.springframework.util.Base64Utils.decode(content.getBytes());
}
public static String encryptBASE64(byte[] bytes) {
return new String(org.springframework.util.Base64Utils.encode(bytes));
}
public static String sign(byte[] data, String privateKey) throws Exception {
// 解密由base64编码的私钥
byte[] keyBytes = decryptBASE64(privateKey);
// 构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取私钥匙对象
PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 用私钥对信息生成数字签名
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(priKey);
signature.update(data);
return encryptBASE64(signature.sign());
}
public static boolean verify(byte[] data, String publicKey, String sign)
throws Exception {
// 解密由base64编码的公钥
byte[] keyBytes = decryptBASE64(publicKey);
// 构造X509EncodedKeySpec对象
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
// KEY_ALGORITHM 指定的加密算法
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
// 取公钥匙对象
PublicKey pubKey = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(pubKey);
signature.update(data);
// 验证签名是否正常
return signature.verify(decryptBASE64(sign));
}
public static byte[] decryptByPrivateKey(byte[] data, String privateKey)
throws Exception {
// 对密钥解密
byte[] keyBytes = decryptBASE64(privateKey);
// 取得私钥
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privatizationKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 对数据解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privatizationKey);
return cipher.doFinal(data);
}
public static String jsencryptDecryptByPrivateKeyLong(String content, String privateKey) {
String resultContent = "";
try {
StringBuffer buffer = new StringBuffer();
if (content != null && content.trim().length() > 0) {
String[] contentList = content.split("=");
for (String item : contentList) {
byte[] itemBytes = Base64Utils.decode((item + "=").getBytes());
try {
byte[] itemResultBytes = decryptByPrivateKey(itemBytes, privateKey);
String itemResultStr = new String(itemResultBytes);
buffer.append(itemResultStr);
} catch (Exception e) {
e.printStackTrace();
}
}
}
resultContent = URLDecoder.decode(buffer.toString());
} catch (Exception e) {
e.printStackTrace();
System.err.println("jsencryptDecryptByPrivateKeyLong解密出错:" + e.getMessage() + ":" + "解密内容:" + content);
throw new RuntimeException("rsa解密失败");
}
return resultContent;
}
public static byte[] decryptByPrivateKey(String data, String privateKey)
throws Exception {
return decryptByPrivateKey(decryptBASE64(data), privateKey);
}
public static byte[] decryptByPublicKey(byte[] data, String publicKey)
throws Exception {
// 对密钥解密
byte[] keyBytes = decryptBASE64(publicKey);
// 取得公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicityKey = keyFactory.generatePublic(x509KeySpec);
// 对数据解密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicityKey);
return cipher.doFinal(data);
}
public static byte[] encryptByPublicKey(String data, String key)
throws Exception {
// 对公钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得公钥
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicKey = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return cipher.doFinal(data.getBytes());
}
public static byte[] encryptByPrivateKey(byte[] data, String key)
throws Exception {
// 对密钥解密
byte[] keyBytes = decryptBASE64(key);
// 取得私钥
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
return cipher.doFinal(data);
}
public static String getPrivateKey(Map<String, Key> keyMap) {
Key key = keyMap.get(PRIVATE_KEY);
return encryptBASE64(key.getEncoded());
}
public static String getPublicKey(Map<String, Key> keyMap) {
Key key = keyMap.get(PUBLIC_KEY);
return encryptBASE64(key.getEncoded());
}
public static ConcurrentHashMap<String, Key> iniTKEy() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
ConcurrentHashMap<String, Key> keyMap = new ConcurrentHashMap<>(2);
keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥
keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥
return keyMap;
}
public static Map<String,Key> initKeyOnce() {
if (KEY_MAP.size() == 0){
synchronized (RsaUtilClient.class){
if (KEY_MAP.size() == 0){
try {
KEY_MAP = initKey();
}catch (Exception e){
e.printStackTrace();
throw new RuntimeException("公钥和私钥初始化失败");
}
}
}
}
return KEY_MAP;
}
public static void main(String[] args) throws Exception {
String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCWh3Nyt+5QqUXw1qHXM4k7lq98f9wA4iQgKK1LB1tr4uIgL/dls0LkBgY4oS/Dn3J0qHkpUTkTT84uMHey7cwdd9k90/65cpdawX0J0KO3S3Zwl9d5AJt7/hdSap3AcHw3dvlrZvvDJ72AaR3YUPujNM3dhLC7tsdDb3CxoJSBDQIDAQAB";
String privateKey = "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";
String inputStr = "sign";
byte[] data = inputStr.getBytes();
byte[] encodedData = RsaUtilClient.encryptByPrivateKey(data, privateKey);
String con = "F41sMcJ0umNgZcFzxIzoLY8eZP8vwE5QNq/slHOuft63bWZwANaK8bvHNtac7/qvohEeP2BBPb80wYtToJGSsUegPu2fIlWoyA+JBVDNHRItJNwwNCgbhnBkUR2T8NGRrpjLHoA8dmAh0l9uaoCDog5ZwvHEOLSzTILvY4Rei2U=gB15njJfeQqbNJe2qQ3ui6J88vyjHDL4FKw3KWbY2iXyQM/b+RQt9kgnb0nDhAuZkJ5BWTQorpmyiAQYHaQmz5JgDpZCyw8E4XOXPgZXKgLXkEXwLlhwOhhoH5QsqCieqzu2pG6CcGeYycU+yy2fSs1VPRNIfPpeHde76ZH3urg=YRw5Y0abdEmoaLk0iz44nOPxrO4qBrIBvtBTeAQWv5Dme6YFXOxNIFd63FpE0o5c3nplueDJF17bNbIVT+rAkb54mR/jRXygvosach2ONlM/kw6UaV5lQ+BAAt/+71I7wGqxTvyxz1UFWmIIiYszQxxWIhUxH3hYXY7uHTVOg18=MMLZEy3iNkhZiPuEoLcjRKgVB6HnEY9ywVffY3B/ZBQhUqrONwkjfoh8k5w+xhT7VhMStKCxgfzNNRmKCxvxlLY86nGkZ9l9pkGJqfCQwJSNSP1eYszafgtoOn6/Rc7znPoxxhJ0AWmlcUEB+8PnePO9ApAKai0Jdx4KbpbC7Fg=";
// byte[] decodedData = RSACode.decryptByPrivateKey(Base64Utils.decode(con.getBytes()), privateKey);
String result = RsaUtilClient.jsencryptDecryptByPrivateKeyLong(con, privateKey);
// String outputStr = new String(decodedData);
// outputStr = URLDecoder.decode(outputStr);
System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + result);
System.err.println("私钥签名——公钥验证签名");
// 产生签名
String sign = RsaUtilClient.sign(encodedData, privateKey);
System.err.println("签名:" + sign);
// 验证签名
boolean status = RsaUtilClient.verify(encodedData, publicKey, sign);
System.err.println("状态:" + status);
}
}
RsaTestController 分发公钥和利用私钥解密的controller
package com.example.oracles.controller;
import com.example.oracles.utils.AjaxResult;
import com.example.oracles.utils.RsaUtilClient;
import org.springframework.WEB.bind.annotation.*;
import java.security.Key;
import java.util.Map;
@CrossOrigin
@RestController
@RequestMapping("/rsa")
public class RsaTestController {
@GetMapping("/getPublicKey")
public AjaxResult getPublicKey() {
Map<String, Key> keyMap = RsaUtilClient.initKeyOnce();
String publicKey = RsaUtilClient.getPublicKey(keyMap);
AjaxResult<String> ajaxResult = new AjaxResult<>("获取公钥成功", publicKey);
return ajaxResult;
}
@PostMapping("/privateKeyDecode")
public AjaxResult privateKeyDecode(@RequestBody Map<String,String> params){
Map<String, Key> keyMap = RsaUtilClient.initKeyOnce();
String privateKey = RsaUtilClient.getPrivateKey(keyMap);
String content = params.get("content");
try {
String decrypt = RsaUtilClient.jsencryptDecryptByPrivateKeyLong(content, privateKey);
return new AjaxResult<>("解密成功",decrypt);
}catch (Exception e){
e.printStackTrace();
return new AjaxResult<>("解密失败");
}
}
}
AjaxResult 请求响应工具类
package com.example.oracles.utils;
import java.io.Serializable;
public class AjaxResult<T> implements Serializable {
private static final long serialVersionUID = 6715651583113612048L;
public static final int SUCCESS = 200;
public static final int ERROR = 500;
public static final int SYSTEM_ERROR = -1;
public static final String SUCCESS_MESSAGE = "请求成功";
public static final String NONE_PERMISSION_MESSAGE = "权限不足,请联系管理员";
public static final String ERROR_MESSAGE = "系统异常,请联系管理员";
private int code;
private String errCode;
private String msg;
private T content;
public AjaxResult() {
super();
this.code = SUCCESS;
}
public AjaxResult(String msg) {
super();
this.code = ERROR;
this.msg = msg;
}
public AjaxResult(T content) {
super();
this.code = SUCCESS;
this.msg = SUCCESS_MESSAGE;
this.content = content;
}
public AjaxResult(int code, String msg, T content) {
super();
this.code = code;
this.msg = msg;
this.content = content;
}
public AjaxResult(int code, String msg) {
super();
this.code = code;
this.msg = msg;
}
public AjaxResult(String msg, T content) {
super();
this.code = SUCCESS;
this.msg = msg;
this.content = content;
}
public AjaxResult(int code, String errCode, String msg, T content) {
super();
this.code = code;
this.errCode = errCode;
this.msg = msg;
this.content = content;
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getErrCode() {
return errCode;
}
public void setErrCode(String errCode) {
this.errCode = errCode;
}
public String getMsg() {
return msg;
}
public void setMsg(String msg) {
this.msg = msg;
}
public T getContent() {
return content;
}
public void setResult(T data) {
this.content = data;
}
}
以上就是Java实现前端jsencrypt.js加密后端解密的示例代码的详细内容，更多关于Java前端加密 后端解密的资料请关注其它相关文章！
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