因为Rsa加密的代码都是比较通用的，所以没有特意去整合，这里参照着两位大神的代码重新写了一遍，做了一些简单的修改，符合本地运行环境
服务端代参照：http://www.cnblogs.com/zhujiabin/p/7118126.html
客户端代码参照：https://jackiedark.github.io/2018/02/05/JSEncrypt%E9%95%BF%E6%96%87%E6%9C%AC%E5%88%86%E6%AE%B5%E5%8A%A0%E8%A7%A3%E5%AF%86/
JS加密依赖：jsencrypt.jsGithub地址：https://github.com/travist/jsencrypt可客户端尽量依赖JAVA自带的Jar，只是Base64加密的时候额外依赖了apache的工具类commons-net-3.3.jar
服务端工RSA工具类
package com.wzh.config.utils;import org.apache.commons.net.util.Base64;import org.apache.log4j.Logger;import javax.crypto.Cipher;import java.io.ByteArrayOutputStream;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.HashMap;import java.util.Map;/** * <RSA加密解密工具类> * <额外依赖 commons-net-3.3.jar,日志用的log4j，如果是其他的日志框架可以更改> * @author wzh * @version 2018-12-16 18:20 * @see [相关类/方法] (可选) **/public class RsaUtils{ private static Logger log = Logger.getLogger(RsaUtils.class); /** * 块加密大小 */ private static final int CACHE_SIZE = 1024; /** * 加密算法RSA */ public static final String KEY_ALGORITHM = "RSA"; /** * 签名算法 */ public static final String SIGNATURE_ALGORITHM = "MD5withRSA"; /** * 获取公钥的key */ private static final String PUBLIC_KEY = "RsaPublicKey"; /** * 获取私钥的key */ private static final String PRIVATE_KEY = "RsaPrivateKey"; /** * RSA最大加密明文大小 */ private static final int MAX_ENCRYPT_BLOCK = 117; /** * RSA最大解密密文大小 */ private static final int MAX_DECRYPT_BLOCK = 128; /** * Base64字符串解码为二进制数据 * @param base64 * @return 二进制数据 * @throws Exception */ public static byte[] decodeBase64(String base64) throws Exception { return Base64.decodeBase64(base64.getBytes()); } /** * 二进制数据编码为Base64字符串 * @param bytes * @return Base64字符串 * @throws Exception */ public static String encodeBase64(byte[] bytes) throws Exception { return new String(Base64.encodeBase64(bytes)); } /** * 生成秘钥对 * @return 返回公钥和私钥的Map集合 * @throws Exception */ public static Map<String, Object> initKeyPair() throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM); keyPairGen.initialize(CACHE_SIZE); KeyPair keyPair = keyPairGen.generateKeyPair(); RSAPublicKey publicKey = (RSAPublicKey)keyPair.getPublic(); RSAPrivateKey privateKey = (RSAPrivateKey)keyPair.getPrivate(); Map<String, Object> keyMap = new HashMap<String, Object>(2); // 公钥 keyMap.put(PUBLIC_KEY, publicKey); // 私钥 keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } /** * 获取私钥 * @param keyMap 秘钥对Map * @return 私钥字符串 * @throws Exception */ public static String getPrivateKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PRIVATE_KEY); return encodeBase64(key.getEncoded()); } /** * 获取公钥字符串 * @param keyMap 秘钥对Map * @return 公钥字符串 * @throws Exception */ public static String getPublicKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PUBLIC_KEY); return encodeBase64(key.getEncoded()); } /** * 使用私钥生成数字签名 * @param data 使用私钥加密的数据 * @param privateKey 是哟啊字符串 * @return 数字签名 * @throws Exception */ public static String sign(byte[] data, String privateKey) throws Exception { // 获取byte数组 byte[] keyBytes = decodeBase64(privateKey); // 构造PKCS8EncodedKeySpec对象 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); // 指定的加密算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 取私钥匙对象 PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec); // 用私钥对信息生成数字签名 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initSign(privateK); signature.update(data); return encodeBase64(signature.sign()); } /** * 校验数字签名 * @param data 私钥加密的数据 * @param publicKey 公钥字符串 * @param sign 私钥生成的签名 * @return 校验成功返回true 失败返回false * @throws Exception */ public static boolean verify(byte[] data, String publicKey, String sign) throws Exception { // 获取byte数组 byte[] keyBytes = decodeBase64(publicKey); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); // 构造X509EncodedKeySpec对象 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 指定的加密算法 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); // 取公钥匙对象 PublicKey publicK = keyFactory.generatePublic(keySpec); signature.initVerify(publicK); signature.update(data); // 验证签名是否正常 return signature.verify(decodeBase64(sign)); } /** * 私钥加密 * @param data 需要加密的数据 * @param privateKey 私钥 * @return 加密后的数据 * @throws Exception */ public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception { byte[] keyBytes = decodeBase64(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateK); int inputLen = data.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); } else { cache = cipher.doFinal(data, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_ENCRYPT_BLOCK; } byte[] encryptedData = out.toByteArray(); out.close(); return encryptedData; } /** * 公钥加密 * @param data 需要加密的数据 * @param publicKey 公钥字符串 * @return 加密后的数据 * @throws Exception */ public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception { byte[] keyBytes = decodeBase64(publicKey); X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicK = keyFactory.generatePublic(x509KeySpec); // 对数据加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, publicK); int inputLen = data.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); } else { cache = cipher.doFinal(data, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_ENCRYPT_BLOCK; } byte[] encryptedData = out.toByteArray(); out.close(); return encryptedData; } /** * 私钥解密 * @param encryptedData 公钥加密的数据 * @param privateKey 私钥字符串 * @return 私钥解密的数据 * @throws Exception */ public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception { byte[] keyBytes = decodeBase64(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateK); int inputLen = encryptedData.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段解密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_DECRYPT_BLOCK) { cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); } else { cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_DECRYPT_BLOCK; } byte[] decryptedData = out.toByteArray(); out.close(); return decryptedData; } /** * 公钥解密 * @param encryptedData 私钥加密的数据 * @param publicKey 公钥字符串 * @return 公钥解密的数据 * @throws Exception */ public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception { byte[] keyBytes = decodeBase64(publicKey); X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicK = keyFactory.generatePublic(x509KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, publicK); int inputLen = encryptedData.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段解密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_DECRYPT_BLOCK) { cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); } else { cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_DECRYPT_BLOCK; } byte[] decryptedData = out.toByteArray(); out.close(); return decryptedData; } /** * 公钥加密方法 * @param data 需加密的字符串 * @param PUBLICKEY 公钥字符串 * @return 加密后的字符串 */ public static String encryptedDataByPublic(String data, String PUBLICKEY) { try { data = encodeBase64(encryptByPublicKey(data.getBytes(), PUBLICKEY)); } catch (Exception e) { e.printStackTrace(); log.error(e.getMessage(),e); } return data; } /** * 私钥解密方法 * @param data 公钥加密的字符串 * @param PRIVATEKEY 私钥字符串 * @return 私钥解密的字符串 */ public static String decryptDataByPrivate(String data, String PRIVATEKEY) { String temp = ""; try { byte[] rs = decodeBase64(data); //以utf-8的方式生成字符串 temp = new String(decryptByPrivateKey(rs, PRIVATEKEY),"UTF-8"); } catch (Exception e) { e.printStackTrace(); } return temp; } public static void main(String[] args) { try { Map<String, Object> keyMap = RsaUtils.initKeyPair(); String publicKey = RsaUtils.getPublicKey(keyMap); String privateKey = RsaUtils.getPrivateKey(keyMap); System.out.println("公钥：" + publicKey); System.out.println("私钥：" + privateKey); String source = "我是需要私钥加密的字符串！"; System.out.println("签名验证逻辑，私钥加密--公钥解密，需要加密的字符串：" + source); byte[] data = source.getBytes(); byte[] encodedData = RsaUtils.encryptByPrivateKey(data, privateKey); System.out.println("私钥加密后：" + new String(encodedData)); String sign = RsaUtils.sign(encodedData, privateKey); System.out.println("签名:" + sign); boolean status = RsaUtils.verify(encodedData, publicKey, sign); System.out.println("验证结果:" + status); byte[] decodedData = RsaUtils.decryptByPublicKey(encodedData, publicKey); String target = new String(decodedData); System.out.println("公钥解密私钥加密的数据:" + target); System.out.println("---------公钥加密----私钥解密----------"); // 这里尽量长一点，复制了一段歌词 String msg = "月溅星河，长路漫漫，风烟残尽，独影阑珊；谁叫我身手不凡，谁让我爱恨两难，到后来，" + "肝肠寸断。幻世当空，恩怨休怀，舍悟离迷，六尘不改；且怒且悲且狂哉，是人是鬼是妖怪，不过是，" + "心有魔债。叫一声佛祖，回头无岸，跪一人为师，生死无关；善恶浮世真假界,尘缘散聚不分明，难断！" + "我要这铁棒有何用，我有这变化又如何；还是不安，还是氐惆，金箍当头，欲说还休。我要这铁棒醉舞魔，" + "我有这变化乱迷浊；踏碎灵霄，放肆桀骜，世恶道险，终究难逃。"; String ecodeMsg = RsaUtils.encryptedDataByPublic(msg,publicKey); System.out.println("加密后的歌词：" + ecodeMsg); String decodeMsg = RsaUtils.decryptDataByPrivate(ecodeMsg,privateKey); System.out.println("解密后的歌词：" + decodeMsg); } catch (Exception e) { e.printStackTrace(); } }}
首先测试一下工具类，main函数跑一下，成功验证签名，加密，解密
image.png
客户端JS代码，需要JSEncrypt库，前文有给出github地址，这里对这个库做一个简单的扩展，因为RSA长文本超过秘钥长度要报错，所以需要扩展修改下
/** * --------------------------- * 此JS需加载JSEncrypt库的后面，加密解密调用着两个方法 * --------------------------- *//** * 长文本加密 * @param {string} string 待加密长文本 * @returns {string} 加密后的base64编码* */JSEncrypt.prototype.encryptLong = function (string) { var k = this.getKey(); try { var ct = ""; //RSA每次加密117bytes，需要辅助方法判断字符串截取位置 //1.获取字符串截取点 var bytes = new Array(); bytes.push(0); var byteNo = 0; var len, c; len = string.length; var temp = 0; for (var i = 0; i < len; i++) { c = string.charCodeAt(i); if (c >= 0x010000 && c <= 0x10FFFF) { //特殊字符，如Ř，Ţ byteNo += 4; } else if (c >= 0x000800 && c <= 0x00FFFF) { //中文以及标点符号 byteNo += 3; } else if (c >= 0x000080 && c <= 0x0007FF) { //特殊字符，如È，Ò byteNo += 2; } else { // 英文以及标点符号 byteNo += 1; } if ((byteNo % 117) >= 114 || (byteNo % 117) == 0) { if (byteNo - temp >= 114) { bytes.push(i); temp = byteNo; } } } //2.截取字符串并分段加密 if (bytes.length > 1) { for (var i = 0; i < bytes.length - 1; i++) { var str; if (i == 0) { str = string.substring(0, bytes[i + 1] + 1); } else { str = string.substring(bytes[i] + 1, bytes[i + 1] + 1); } var t1 = k.encrypt(str); ct += t1; } ; if (bytes[bytes.length - 1] != string.length - 1) { var lastStr = string.substring(bytes[bytes.length - 1] + 1); ct += k.encrypt(lastStr); } return hex2b64(ct); } var t = k.encrypt(string); var y = hex2b64(t); return y; } catch (ex) { console.log(ex); return false; }};/** * 长文本解密 * @param {string} string 加密后的base64编码 * @returns {string} 解密后的原文 * */JSEncrypt.prototype.decryptLong = function (string) { var k = this.getKey(); var maxLength = 128; try { var string = b64tohex(string); var ct = ""; if (string.length > maxLength * 2) { var lt = string.match(/.{1,256}/g); //128位解密。取256位 lt.forEach(function (entry) { var t1 = k.decrypt(entry); ct += t1; }); return ct; } var y = k.decrypt(string); return y; } catch (ex) { return false; }};function hex2b64(h) { var b64map="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; var b64padchar="="; var i; var c; var ret = ""; for(i = 0; i+3 <= h.length; i+=3) { c = parseInt(h.substring(i,i+3),16); ret += b64map.charAt(c >> 6) + b64map.charAt(c & 63); } if(i+1 == h.length) { c = parseInt(h.substring(i,i+1),16); ret += b64map.charAt(c << 2); } else if(i+2 == h.length) { c = parseInt(h.substring(i,i+2),16); ret += b64map.charAt(c >> 2) + b64map.charAt((c & 3) << 4); } while((ret.length & 3) > 0) ret += b64padchar; return ret;}
一个简单的测试页面，就不做前后台衔接了，只是在前提用后台生成的公钥进行加密，然后后台main方法解密一下。
<!DOCTYPE html><html> <head> <title>MyHtml.html</title> <meta name="keywords" content="keyword1,keyword2,keyword3"> <meta name="description" content="this is my page"> <meta name="content-type" content="text/html; charset=UTF-8"> <script src="${request.contextPath}/js/jquery-3.3.1.min.js"></script> <script src="${request.contextPath}/js/jsencrypt.js?v=123"></script> <script src="${request.contextPath}/js/RsaJs.js?v=321123"></script> <script type="text/javascript"> $(function() { $('#submit').click(function() { var data = $('#msg').val(); // 公钥 var publickey = $('#publickey').val(); // 使用jsencrypt库加密前端参数 var jsencrypt = new JSEncrypt(); jsencrypt.setPublicKey(publickey); // 这里调用长文本的加密方法 var ecodeMsg = jsencrypt.encryptLong(data); $('#ecodeMsg').val(ecodeMsg); }); }); </script> </head> <body> 需要加密的内容:</br><textarea id="msg" name="msg" rows="10" cols="60"></textarea></br> 公钥:</br><textarea id="publickey" rows="10" cols="60"></textarea></br> 密文:</br><textarea id="ecodeMsg" rows="10" cols="60"></textarea> <br/> <br/> <input id="submit" type="button" value="加密" /> </body> </body></html>
简单的测试，页面获取密文
image.png
后台main解密一下
import com.wzh.config.utils.RsaUtils;/** * <一句话功能描述> * <功能详细描述> * @author wzh * @version 2018-12-16 23:31 * @see [相关类/方法] (可选) **/public class RsaManTest { public static void main(String[] args) { String msg = RsaUtils.decryptDataByPrivate("XsM6CYaNhdx2pJXebCgl3g3pF7FX9KrPY+gtwgbQs0Q1mqJL4VHqQytxOJfUwXHLP/hLck80AWSctJ29/dB4IQ2mSbcO4OInAJMkPwqWsnh1E9bFlFP2KjQ5RBVngb//IiSgBSFo8NR00y1/h47CrNch6ljW1nCLG82Qk2olhfI=", "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"); System.out.println(msg); }}
前台加密，后台解密成功