Java加解密

• 介绍

本文介绍如何利用Java语言加密数据。

• 对称加密
• DES（Data Encryption Standard）

[codesyntax lang="java"]

/*** Copyright © 1998-2015, surenpi.com All Rights Reserved.*/package org.suren.hibernate.util;import java.io.ByteArrayOutputStream;import java.security.InvalidKeyException;import java.security.NoSuchAlgorithmException;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.KeyGenerator;import javax.crypto.NoSuchPaddingException;import javax.crypto.SecretKey;/** * @author suren * @date 2015年11月24日 下午5:04:05 */public class Encryptor{private KeyGeneratorkeyGen;private SecretKeykey;private Ciphercipher;private byte[]cipherByte;public static final String ALG_DES = "DES";private static Encryptor encryptor;private Encryptor(){}private Encryptor(String algorithm) throws NoSuchAlgorithmException, NoSuchPaddingException{keyGen = KeyGenerator.getInstance(algorithm);key = keyGen.generateKey();cipher = Cipher.getInstance(algorithm);}public static Encryptor getInstance(String algorithm) throws NoSuchAlgorithmException, NoSuchPaddingException{if(encryptor == null){encryptor = new Encryptor(algorithm);}return encryptor;}public byte[] encrypt(String str) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException{cipher.init(Cipher.ENCRYPT_MODE, key);cipherByte = cipher.doFinal(str.getBytes());return cipherByte;}public String encryptStr(String str) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException{byte[] encryptArray = encrypt(str);StringBuffer strBuf = new StringBuffer();for(byte e : encryptArray){strBuf.append(intToChar((e >> 4) & 0x0f));strBuf.append(intToChar(e & 0x0f));}return strBuf.toString();}public byte[] decrypt(byte[] buf) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException{cipher.init(Cipher.DECRYPT_MODE, key);cipherByte = cipher.doFinal(buf);return cipherByte;}public String decryptStr(byte[] buf) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException{return new String(decrypt(buf));}/** * decrypt string * @see #encryptStr(String) * @param encryptStr * @return * @throws InvalidKeyException * @throws IllegalBlockSizeException * @throws BadPaddingException * @throws NullPointerException if encryptStr is null */public String decryptStr(String encryptStr) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException{if(encryptStr == null){throw new NullPointerException();}encryptStr = encryptStr.toUpperCase();ByteArrayOutputStream byteOut = new ByteArrayOutputStream();int len = encryptStr.length();for(int i = 0; i < len; i += 2){int b = ((charToByte(encryptStr.charAt(i)) << 4) & 0xff) | charToByte(encryptStr.charAt(i + 1));byteOut.write(b);}return decryptStr(byteOut.toByteArray());}private byte charToByte(char c){return (byte) "0123456789ABCDEF".indexOf(c);}private char intToChar(int b){return "0123456789ABCDEF".charAt(b);}public void clean(){cipherByte = null;}}

[/codesyntax]

• 3DES
• AES（Advanced Encryption Standard）
• BASE64
• 非对称加密
• RSA
• DSA（Digital Signature Algorithm）
• 参考

http://www.iteye.com/topic/1122076/

查看原文：http://surenpi.com/2015/11/27/java%e5%8a%a0%e8%a7%a3%e5%af%86/