AES和RSA：加密解密

最近生活乱七八糟，什么都懒上了天。感觉自己会的东西好少 领导新分配了一个任务，让我将http换成https，对参数进行加密 可选择有两个加密算法AES和RSA 由于公司内部使用，且数据量大，可以用私钥。于是就用AES。

AES

1.概念

AES又叫Rijndael算法，是DES升级的加密标准，运行要求低，不需计算机有非常高的处理能力和大的内存；

操作可以很容易的抵御时间和空间的攻击，在不同的运行环境下始终保持良好的性能；

AES密钥长度：最长只有256bit，可用软件和硬件实现高速处理；

密钥管理：要求在通信前对密钥进行秘密分配，解密的私钥必须通过网络传送至加密数据接收方；

AES加密速度很快；

对称加密；

2.帮助类

import java.io.UnsupportedEncodingException; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.KeyGenerator; import javax.crypto.NoSuchPaddingException; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; import com.util.encrypt.Base64; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class AesEncrypt { private static final String AES_STR = "AES"; private static final String SHA1PRNG_STR = "SHA1PRNG"; public static String encrypt(String bef_aes, String password) { byte[] byteContent = null; try { byteContent = bef_aes.getBytes("utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return encrypt(byteContent,password); } public static String encrypt(byte[] content, String password) { try { SecretKey secretKey = getKey(password); byte[] enCodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(enCodeFormat, AES_STR); Cipher cipher = Cipher.getInstance(AES_STR);// 创建密码器 cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(content); String aft_aes = parseByte2HexStr(result); return aft_aes; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } return null; } public static String decrypt(String aft_aes_base64, String password,String charset){ String aft_aes=""; try { aft_aes = Base64.decode(aft_aes_base64); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } return decrypt(aft_aes,password); } public static String decrypt(String aft_aes, String password) { try { byte[] content = parseHexStr2Byte(aft_aes); SecretKey secretKey = getKey(password); byte[] enCodeFormat = secretKey.getEncoded(); SecretKeySpec key = new SecretKeySpec(enCodeFormat, AES_STR); Cipher cipher = Cipher.getInstance(AES_STR);// 创建密码器 cipher.init(Cipher.DECRYPT_MODE, key);// 初始化 byte[] result = cipher.doFinal(content); String bef_aes = new String(result); return bef_aes; // 加密 } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (NoSuchPaddingException e) { e.printStackTrace(); } catch (InvalidKeyException e) { e.printStackTrace(); } catch (IllegalBlockSizeException e) { e.printStackTrace(); } catch (BadPaddingException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } return null; } public static String parseByte2HexStr(byte buf[]) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < buf.length; i++) { String hex = Integer.toHexString(buf[i] & 0xFF); if (hex.length() == 1) { hex = '0' + hex; } sb.append(hex.toUpperCase()); } return sb.toString(); } public static byte[] parseHexStr2Byte(String hexStr) { if (hexStr.length() < 1) return null; byte[] result = new byte[hexStr.length()/2]; for (int i = 0;i< hexStr.length()/2; i++) { int value = Integer.parseInt(hexStr.substring(i*2, i*2+2), 16); result[i] = (byte)value; } return result; } public static SecretKey getKey(String strKey) { try { KeyGenerator _generator = KeyGenerator.getInstance(AES_STR); SecureRandom secureRandom = SecureRandom.getInstance(SHA1PRNG_STR); secureRandom.setSeed(strKey.getBytes()); _generator.init(128,secureRandom); return _generator.generateKey(); } catch (Exception e) { throw new RuntimeException("初始化密钥出现异常"); } } /** * AES的加密函数 * @param str 传入需要加密的字符 * @param key 传入一个16位长度的密钥。否则报错 * @return 执行成功返回加密结果，否则报错 * @throws Exception 抛出一个加密异常 */ @SuppressWarnings("restriction") public static String aesEncrypt(String str, String key) throws Exception { if (str == null || key == null) return null; Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key.getBytes("utf-8"), "AES")); byte[] bytes = cipher.doFinal(str.getBytes("utf-8")); return new BASE64Encoder().encode(bytes); } /** * AES的解密函数 * @param str 传入需要解密的字符 * @param key 传入一个16位长度的密钥。否则报错 * @return 执行成功返回加密结果，否则报错 * @throws Exception 抛出一个解密异常 */ @SuppressWarnings("restriction") public static String aesDecrypt(String str, String key) throws Exception { if (str == null || key == null) return null; Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key.getBytes("utf-8"), "AES")); byte[] bytes = new BASE64Decoder().decodeBuffer(str); bytes = cipher.doFinal(bytes); return new String(bytes, "utf-8"); } }

3.controller

//如果参数的加密后的字节流，则需要先解密然后转Object @RequestMapping(value="/ts",method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE) public @ResponseBody String aa(@RequestBody String param) { byte[] byteContent = param.getBytes("utf-8"); String key="ABCDEFGHIJKLMNRS";//秘钥 String dataJson="";//加密内容 //去除Base64 和hex：用字符串形式看二进制代码 将二进制转化成16进制 String simpleResult = AesEncrypt.aesEncrypt(dataJson, key);//加密后的密文 String simpleContent= AesEncrypt.aesDecrypt(dataJson, key);//解密后的内容 String result = AesEncrypt.encrypt(dataJson, key);//加密后的密文 String content= AesEncrypt.decrypt(dataJson, key);//解密后的内容 }

RSA

1.概念

是公开密钥系统的代表；

安全性：建立在具有大素数因子的合数，其因子分解困难这一法则之上；

处理速度慢；

密钥管理：加解密过程中不必网络传输保密的密钥；密钥管理优于AES算法；

RSA加解密速度慢，不适合大量数据文件加密；

公钥加密 私钥解密

钥加密 公钥解密 使用签名确定是否为该私钥加密

2.使用

//非对称密钥算法 public static final String KEY_ALGORITHM = "RSA"; /** * 密钥长度，DH算法的默认密钥长度是1024 * 密钥长度必须是64的倍数，在512到65536位之间 */ private static final int KEY_SIZE = 512; //公钥 private static final String PUBLIC_KEY = "RSAPublicKey"; //私钥 private static final String PRIVATE_KEY = "RSAPrivateKey"; /** * 初始化密钥对 * * @return Map 甲方密钥的Map */ public static Map<String, Object> initKey() throws Exception { //实例化密钥生成器 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM); //初始化密钥生成器 keyPairGenerator.initialize(KEY_SIZE); //生成密钥对 KeyPair keyPair = keyPairGenerator.generateKeyPair(); //甲方公钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); //甲方私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); //将密钥存储在map中 Map<String, Object> keyMap = new HashMap<String, Object>(); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } /** * 私钥加密 * * @param data 待加密数据 * @param key 密钥 * @return byte[] 加密数据 */ public static byte[] encryptByPrivateKey(byte[] data, byte[] key) throws Exception { //取得私钥 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //生成私钥 PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec); //数据加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 公钥加密 * * @param data 待加密数据 * @param key 密钥 * @return byte[] 加密数据 */ public static byte[] encryptByPublicKey(byte[] data, byte[] key) throws Exception { //实例化密钥工厂 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //初始化公钥 //密钥材料转换 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key); //产生公钥 PublicKey pubKey = keyFactory.generatePublic(x509KeySpec); //数据加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, pubKey); return cipher.doFinal(data); } /** * 私钥解密 * * @param data 待解密数据 * @param key 密钥 * @return byte[] 解密数据 */ public static byte[] decryptByPrivateKey(byte[] data, byte[] key) throws Exception { //取得私钥 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(key); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //生成私钥 PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec); //数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 公钥解密 * * @param data 待解密数据 * @param key 密钥 * @return byte[] 解密数据 */ public static byte[] decryptByPublicKey(byte[] data, byte[] key) throws Exception { //实例化密钥工厂 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //初始化公钥 //密钥材料转换 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(key); //产生公钥 PublicKey pubKey = keyFactory.generatePublic(x509KeySpec); //数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, pubKey); return cipher.doFinal(data); } /** * 取得私钥 * * @param keyMap 密钥map * @return byte[] 私钥 */ public static byte[] getPrivateKey(Map<String, Object> keyMap) { Key key = (Key) keyMap.get(PRIVATE_KEY); return key.getEncoded(); } /** * 取得公钥 * * @param keyMap 密钥map * @return byte[] 公钥 */ public static byte[] getPublicKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PUBLIC_KEY); return key.getEncoded(); }

使用

//初始化密钥 //生成密钥对 Map<String, Object> keyMap = initKey(); //公钥 byte[] publicKey = getPublicKey(keyMap); //私钥 byte[] privateKey = getPrivateKey(keyMap); System.out.println("公钥：/n" + Base64.encodeBase64String(publicKey)); System.out.println("私钥：/n" + Base64.encodeBase64String(privateKey)); System.out.println("================密钥对构造完毕,甲方将公钥公布给乙方，开始进行加密数据的传输============="); String str = "RSA密码交换算法"; System.out.println("/n===========甲方向乙方发送加密数据=============="); System.out.println("原文:" + str); //甲方进行数据的加密 byte[] code1 = encryptByPrivateKey(str.getBytes(), privateKey); System.out.println("加密后的数据：" + Base64.encodeBase64String(code1)); System.out.println("===========乙方使用甲方提供的公钥对数据进行解密=============="); //乙方进行数据的解密 byte[] decode1 = decryptByPublicKey(code1, publicKey); System.out.println("乙方解密后的数据：" + new String(decode1) + "/n/n"); System.out.println("===========反向进行操作，乙方向甲方发送数据==============/n/n"); str = "乙方向甲方发送数据RSA算法"; System.out.println("原文:" + str); //乙方使用公钥对数据进行加密 byte[] code2 =encryptByPublicKey(str.getBytes(), publicKey); System.out.println("===========乙方使用公钥对数据进行加密=============="); System.out.println("加密后的数据：" + Base64.encodeBase64String(code2)); System.out.println("=============乙方将数据传送给甲方======================"); System.out.println("===========甲方使用私钥对数据进行解密=============="); //甲方使用私钥对数据进行解密 byte[] decode2 = decryptByPrivateKey(code2, privateKey); System.out.println("甲方解密后的数据：" + new String(decode2));