java RSAUtils 加密工具类操作

1.RSA加密算法是一种非对称加密算法。在公开密钥加密和电子商业中RSA被广泛使用。RSA公开密钥密码体制。所谓的公开密钥密码体制就是使用不同的加密密钥与解密密钥，是一种“由已知加密密钥推导出解密密钥在计算上是不可行的”密码体制。在公开密钥密码体制中，加密密钥（即公开密钥）PK是公开信息，而解密密钥（即秘密密钥）SK是需要保密的。加密算法E和解密算法D也都是公开的。虽然解密密钥SK是由公开密钥PK决定的，但却不能根据PK计算出SK。

2.本工具类涉及到BASE64编码，所以先展示出BASE64Utils：

package com.example.springboottest.common.util; import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder;import java.security.MessageDigest; /** * BASE64的加解密 * @author Neo * @date 2018-4-15 22:21:51 * */@SuppressWarnings('restriction')public class Base64Utils { public static final String KEY_SHA = 'SHA'; public static final String KEY_MD5 = 'MD5'; /** * BASE64解密 * * @param key * @return * @throws Exception */ public static byte[] decryptBASE64(String key) throws Exception { return (new BASE64Decoder()).decodeBuffer(key); } /** * BASE64加密 * * @param key * @return * @throws Exception */ public static String encryptBASE64(byte[] key) throws Exception { return (new BASE64Encoder()).encodeBuffer(key); } /** * MD5加密 * * @param data * @return * @throws Exception */ public static byte[] encryptMD5(byte[] data) throws Exception { MessageDigest md5 = MessageDigest.getInstance(KEY_MD5); md5.update(data); return md5.digest(); } /** * SHA加密 * * @param data * @return * @throws Exception */ public static byte[] encryptSHA(byte[] data) throws Exception { MessageDigest sha = MessageDigest.getInstance(KEY_SHA); sha.update(data); return sha.digest(); } }

3.然后我们展示RSAUtils：

package com.example.springboottest.common.util; 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.HashMap;import java.util.Map; /** * RSA安全编码组件 * * @version 1.0 * @desc 公钥和私钥存放在properties文件的时候每行的末尾加上“rn” <br/> * “rn” 起到换行的作用,最后的“”在properties在里表示连接 * * @author Neo * @date 2018-4-15 22:23:19 * @since 1.0 */public class RSAUtils extends Base64Utils { 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'; /** * 用私钥对信息生成数字签名 * * @param data 加密数据 * @param privateKey 私钥 * @return * @throws Exception */ public static String sign(String data, String privateKey) throws Exception { return sign(data.getBytes(), privateKey); } /** * 用私钥对信息生成数字签名 * * @param data 加密数据 * @param privateKey 私钥 * @return * @throws Exception */ 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()); } /** * 校验数字签名 * * @param data 加密数据 * @param publicKey 公钥 * @param sign 数字签名 * @return 校验成功返回true 失败返回false * @throws Exception */ public static boolean verify(String data, String publicKey, String sign) throws Exception { return verify(data.getBytes(), publicKey, sign); } /** * 校验数字签名 * * @param data 加密数据 * @param publicKey 公钥 * @param sign 数字签名 * @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 { // 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)); } /** * 解密<br> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static String decryptByPrivateKey(String data, String key) throws Exception { return new String(decryptByPrivateKey(Base64Utils.decryptBASE64(data), key)); } /** * 解密<br> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPrivateKey(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); // 对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 解密<br> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static String decryptByPublicKey(String data, String key) throws Exception { return new String(decryptByPublicKey(Base64Utils.decryptBASE64(data), key)); } /** * 解密<br> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPublicKey(byte[] data, String key) throws Exception { // 对密钥解密 byte[] keyBytes = decryptBASE64(key); // 取得公钥 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicKey = keyFactory.generatePublic(x509KeySpec); // 对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, publicKey); return cipher.doFinal(data); } /** * 加密<br> * 用公钥加密 * * @param data * @param key * @return * @throws Exception */ public static String encryptByPublicKey(String data, String key) throws Exception { return Base64Utils.encryptBASE64(encryptByPublicKey(data.getBytes(), key)); } /** * 加密<br> * 用公钥加密 * * @param data * @param key * @return * @throws Exception */ public static byte[] encryptByPublicKey(byte[] 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); } /** * 加密<br> * 用私钥加密 * * @param data * @param key * @return * @throws Exception */ public static String encryptByPrivateKey(String data, String key) throws Exception { return Base64Utils.encryptBASE64(encryptByPrivateKey(data.getBytes(), key)); } /** * 加密<br> * 用私钥加密 * * @param data * @param key * @return * @throws Exception */ 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); } /** * 取得私钥 * * @param keyMap * @return * @throws Exception */ public static String getPrivateKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PRIVATE_KEY); return encryptBASE64(key.getEncoded()); } /** * 取得公钥 * * @param keyMap * @return * @throws Exception */ public static String getPublicKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PUBLIC_KEY); return encryptBASE64(key.getEncoded()); } /** * 初始化密钥 * * @return * @throws Exception */ public static Map<String, Object> initKey() throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM); keyPairGen.initialize(1024); KeyPair keyPair = keyPairGen.generateKeyPair(); // 公钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // 私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); Map<String, Object> keyMap = new HashMap<String, Object>(2); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } public static void main(String[] args) { try { Map<String, Object> map = RSAUtils.initKey(); String publicKey = RSAUtils.getPublicKey(map); String privateKey = RSAUtils.getPrivateKey(map); System.out.println('公钥：' + publicKey); System.out.println('私钥：' + privateKey); String data = 'Java是世界上最好的编程语言'; String encryptData = RSAUtils.encryptByPublicKey(data, publicKey); System.out.println('加密后：' + encryptData); String decryptData = RSAUtils.decryptByPrivateKey(encryptData, privateKey); System.out.println('解密后：' + decryptData); } catch (Exception e) { e.printStackTrace(); } }}

4.最后展示测试结果：

补充知识：java使用RSA生成公钥和私钥，并进行加解密

废话不多说，上代码：

import javax.crypto.Cipher;import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder; import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.SecureRandom;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; /** * Java RSA 加密工具类 */public class RSAUtils { /** * 密钥长度 于原文长度对应 以及越长速度越慢 */ private final static int KEY_SIZE = 1024; /** * 用于封装随机产生的公钥与私钥 */ private static Map<Integer, String> keyMap = new HashMap<Integer, String>(); /** * 随机生成密钥对 * @throws Exception */ public static void genKeyPair() throws Exception { // 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 keyPairGen.initialize(KEY_SIZE, 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(); String publicKeyString = encryptBASE64(publicKey.getEncoded()); // 得到私钥字符串 String privateKeyString = encryptBASE64(privateKey.getEncoded()); // 将公钥和私钥保存到Map //0表示公钥 keyMap.put(0, publicKeyString); //1表示私钥 keyMap.put(1, privateKeyString); } //编码返回字符串 public static String encryptBASE64(byte[] key) throws Exception { return (new BASE64Encoder()).encodeBuffer(key); } //解码返回byte public static byte[] decryptBASE64(String key) throws Exception { return (new BASE64Decoder()).decodeBuffer(key); } /** * RSA公钥加密 * * @param str 加密字符串 * @param publicKey 公钥 * @return 密文 * @throws Exception 加密过程中的异常信息 */ public static String encrypt(String str, String publicKey) throws Exception { //base64编码的公钥 byte[] decoded = decryptBASE64(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 = encryptBASE64(cipher.doFinal(str.getBytes('UTF-8'))); return outStr; } /** * RSA私钥解密 * * @param str 加密字符串 * @param privateKey 私钥 * @return 明文 * @throws Exception 解密过程中的异常信息 */ public static String decrypt(String str, String privateKey) throws Exception { //64位解码加密后的字符串 byte[] inputByte = decryptBASE64(str); //base64编码的私钥 byte[] decoded = decryptBASE64(privateKey); 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; } public static void main(String[] args) throws Exception { long temp = System.currentTimeMillis(); //生成公钥和私钥 genKeyPair(); //加密字符串 System.out.println('公钥:' + keyMap.get(0)); System.out.println('私钥:' + keyMap.get(1)); System.out.println('生成密钥消耗时间:' + (System.currentTimeMillis() - temp) / 1000.0 + '秒'); String message = 'RSA测试aaa'; System.out.println('原文:' + message); temp = System.currentTimeMillis(); String messageEn = encrypt(message, keyMap.get(0)); System.out.println('密文:' + messageEn); System.out.println('加密消耗时间:' + (System.currentTimeMillis() - temp) / 1000.0 + '秒'); temp = System.currentTimeMillis(); String messageDe = decrypt(messageEn, keyMap.get(1)); System.out.println('解密:' + messageDe); System.out.println('解密消耗时间:' + (System.currentTimeMillis() - temp) / 1000.0 + '秒'); }}

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