Java加密算法(三)——PBE算法
除了DES,我们还知道有DESede(TripleDES,就是3DES)、AES、Blowfish、RC2、RC4(ARCFOUR)等多种对称加密方式,其实现方式大同小异,这里介绍对称加密的另一个算法——PBE
PBE
PBE——Password-based encryption(基于密码加密)。其特点在于口令由用户自己掌管,不借助任何物理媒体;采用随机数(这里我们叫做盐)杂凑多重加密等方法保证数据的安全性。是一种简便的加密方式。
通过java代码实现如下:Coder类见Java加密算法(一)
import java.security.Key; import java.util.Random; import javax.crypto.Cipher; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.PBEKeySpec; import javax.crypto.spec.PBEParameterSpec; /** * PBE安全编码组件 * */ public abstract class PBECoder extends Coder { /** * 支持以下任意一种算法 * * <pre> * PBEWithMD5AndDES * PBEWithMD5AndTripleDES * PBEWithSHA1AndDESede * PBEWithSHA1AndRC2_40 * </pre> */ public static final String ALGORITHM = "PBEWITHMD5andDES"; /** * 盐初始化 * * @return * @throws Exception */ public static byte[] initSalt() throws Exception { byte[] salt = new byte[8]; Random random = new Random(); random.nextBytes(salt); return salt; } /** * 转换密钥<br> * * @param password * @return * @throws Exception */ private static Key toKey(String password) throws Exception { PBEKeySpec keySpec = new PBEKeySpec(password.toCharArray()); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM); SecretKey secretKey = keyFactory.generateSecret(keySpec); return secretKey; } /** * 加密 * * @param data * 数据 * @param password * 密码 * @param salt * 盐 * @return * @throws Exception */ public static byte[] encrypt(byte[] data, String password, byte[] salt) throws Exception { Key key = toKey(password); PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 100); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, key, paramSpec); return cipher.doFinal(data); } /** * 解密 * * @param data * 数据 * @param password * 密码 * @param salt * 盐 * @return * @throws Exception */ public static byte[] decrypt(byte[] data, String password, byte[] salt) throws Exception { Key key = toKey(password); PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 100); Cipher cipher = Cipher.getInstance(ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, key, paramSpec); return cipher.doFinal(data); } }
再给出一个测试类:
import static org.junit.Assert.*; import org.junit.Test; /** * * PBE测试 * */ public class PBECoderTest { @Test public void test() throws Exception { String inputStr = "abc"; System.err.println("原文: " + inputStr); byte[] input = inputStr.getBytes(); String pwd = "efg"; System.err.println("密码: " + pwd); byte[] salt = PBECoder.initSalt(); byte[] data = PBECoder.encrypt(input, pwd, salt); System.err.println("加密后: " + PBECoder.encryptBASE64(data)); byte[] output = PBECoder.decrypt(data, pwd, salt); String outputStr = new String(output); System.err.println("解密后: " + outputStr); assertEquals(inputStr, outputStr); } }
控制台输出:
原文: abc 密码: efg 加密后: iCZ0uRtaAhE= 解密后: abc
来源于:http://snowolf.iteye.com/blog
posted on 2013-03-25 16:32 restService 阅读(339) 评论(0) 编辑 收藏 举报