RSA之前端加密后端解密

RSA加密解密方式有：
（1）公钥加密，私钥解密；
（2）私钥加密，公钥解密；
此文章中以下我使用的是前端公钥加密，后端私钥解密；

秘钥对生成

http://web.chacuo.net/netrsakeypair
生成对应的公钥和私钥

前端公钥加密

前端加密js文件：
链接: https://pan.baidu.com/s/1NIMayTcmjbMOf7BqPhPQoA 提取码: t7an
下载js文件并引入

<script th:src="@{/js/jsencrypt.min.js}"></script>
<script type="text/javascript">
function rsaPassword() {var encryptor = new JSEncrypt();encryptor.setPublicKey('公钥字符串'); // 设置公钥var rsaPassword=encryptor.encrypt('要加密的字符串');
}
</script>

后端私钥解密

示例

String encryptPassword=RsaUtil.encryptByPublicKey("要加密的字符串","公钥字符串");
System.out.println("加密:"+encryptPassword);
String decryptPassword=RsaUtil.decryptByPrivateKey(encryptPassword,"私钥字符串");
System.out.println("解密:"+decryptPassword);

后端加解密工具类

import javax.crypto.Cipher;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;/*** @author 初颜sir*/
public class RsaUtil {//签名算法名称private static final String RSA_KEY_ALGORITHM = "RSA";//RSA密钥长度,默认密钥长度是1024,密钥长度必须是64的倍数，在512到65536位之间,不管是RSA还是RSA2长度推荐使用2048private static final int KEY_SIZE = 2048;/*** 公钥加密(用于数据加密)** @param data         加密前的字符串* @param publicKeyStr base64编码后的公钥* @return base64编码后的字符串* @throws Exception*/public static String encryptByPublicKey(String data, String publicKeyStr) throws Exception {//Java原生base64解码byte[] pubKey = Base64.getDecoder().decode(publicKeyStr);//创建X509编码密钥规范X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);//返回转换指定算法的KeyFactory对象KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);//根据X509编码密钥规范产生公钥对象PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);//根据转换的名称获取密码对象Cipher（转换的名称：算法/工作模式/填充模式）Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());//用公钥初始化此Cipher对象（加密模式）cipher.init(Cipher.ENCRYPT_MODE, publicKey);//对数据加密byte[] encrypt = cipher.doFinal(data.getBytes());//返回base64编码后的字符串return Base64.getEncoder().encodeToString(encrypt);}/*** 私钥解密(用于数据解密)** @param data          解密前的字符串* @param privateKeyStr 私钥* @return 解密后的字符串* @throws Exception*/public static String decryptByPrivateKey(String data, String privateKeyStr) throws Exception {//Java原生base64解码byte[] priKey = Base64.getDecoder().decode(privateKeyStr);//创建PKCS8编码密钥规范PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);//返回转换指定算法的KeyFactory对象KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);//根据PKCS8编码密钥规范产生私钥对象PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);//根据转换的名称获取密码对象Cipher（转换的名称：算法/工作模式/填充模式）Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());//用私钥初始化此Cipher对象（解密模式）cipher.init(Cipher.DECRYPT_MODE, privateKey);//对数据解密byte[] decrypt = cipher.doFinal(Base64.getDecoder().decode(data));//返回字符串return new String(decrypt);}/*** 私钥加密(用于数据签名)** @param data          加密前的字符串* @param privateKeyStr base64编码后的私钥* @return base64编码后后的字符串* @throws Exception*/public static String encryptByPrivateKey(String data, String privateKeyStr) throws Exception {//Java原生base64解码byte[] priKey = Base64.getDecoder().decode(privateKeyStr);//创建PKCS8编码密钥规范PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(priKey);//返回转换指定算法的KeyFactory对象KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);//根据PKCS8编码密钥规范产生私钥对象PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);//根据转换的名称获取密码对象Cipher（转换的名称：算法/工作模式/填充模式）Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());//用私钥初始化此Cipher对象（加密模式）cipher.init(Cipher.ENCRYPT_MODE, privateKey);//对数据加密byte[] encrypt = cipher.doFinal(data.getBytes());//返回base64编码后的字符串return Base64.getEncoder().encodeToString(encrypt);}/*** 公钥解密(用于数据验签)** @param data         解密前的字符串* @param publicKeyStr base64编码后的公钥* @return 解密后的字符串* @throws Exception*/public static String decryptByPublicKey(String data, String publicKeyStr) throws Exception {//Java原生base64解码byte[] pubKey = Base64.getDecoder().decode(publicKeyStr);//创建X509编码密钥规范X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(pubKey);//返回转换指定算法的KeyFactory对象KeyFactory keyFactory = KeyFactory.getInstance(RSA_KEY_ALGORITHM);//根据X509编码密钥规范产生公钥对象PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);//根据转换的名称获取密码对象Cipher（转换的名称：算法/工作模式/填充模式）Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());//用公钥初始化此Cipher对象（解密模式）cipher.init(Cipher.DECRYPT_MODE, publicKey);//对数据解密byte[] decrypt = cipher.doFinal(Base64.getDecoder().decode(data));//返回字符串return new String(decrypt);}}