【Java加密解密】DES加密算法

对称加密算法

加密密钥和解密密钥是同一个。

常见的包括：DES，3DES，PBE，IDEA……

DES算法，IBM提交的解决方案。后被破解，3DES是其改进版本。

DES（Data Encryption Standard）数据加密标准

DES默认密钥长度56位，JDK实现长度56，BC实现长度64

3DES是DES改进版本，当然还有2DES和4DES，常用是3DES，长度为168或者112.

注明：

BounCycastle： ouncy Castle 是一种用于 Java 平台的开放源码的轻量级密码术包。它支持大量的密码术算法，并提供 JCE 1.2.1 的实现。因为 Bouncy Castle 被设计成轻量级的，所以从 J2SE 1.4 到 J2ME（包括 MIDP）平台，它都可以运行。它是在 MIDP 上运行的唯一完整的密码术包。

DES和3DES的JDK实现和BC实现算法实现如下：

package com.ufgov;import java.security.Key;import java.security.Security;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import org.apache.commons.codec.binary.Hex;import org.bouncycastle.jce.provider.BouncyCastleProvider;public class DesSercurty {public static void main(String[] args) {jdkDES();bcDES();jdk3DES();bc3DES();}// JDK DES算法实现private static void jdkDES() {try {// 生成密钥KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");keyGenerator.getProvider();System.out.println(keyGenerator.getProvider());keyGenerator.init(56);SecretKey secretKey = keyGenerator.generateKey();byte[] bytesKey = secretKey.getEncoded();// key转换DESKeySpec desKeySpec = new DESKeySpec(bytesKey);SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");Key convertsecretKey = keyFactory.generateSecret(desKeySpec);// 加密Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");cipher.init(Cipher.ENCRYPT_MODE, convertsecretKey);String src = "加密的字符串";byte[] result = cipher.doFinal(src.getBytes());System.out.println("result des encrypt:"+ Hex.encodeHexString(result));// 解密cipher.init(Cipher.DECRYPT_MODE, convertsecretKey);result = cipher.doFinal(result);System.out.println("result des decrypt:" + new String(result));} catch (Exception e) {e.printStackTrace();}}private static void bcDES() {try {Security.addProvider(new BouncyCastleProvider());// 生成密钥KeyGenerator keyGenerator = KeyGenerator.getInstance("DES", "BC");keyGenerator.getProvider();System.out.println(keyGenerator.getProvider());keyGenerator.init(56);SecretKey secretKey = keyGenerator.generateKey();byte[] bytesKey = secretKey.getEncoded();// key转换DESKeySpec desKeySpec = new DESKeySpec(bytesKey);SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");Key convertsecretKey = keyFactory.generateSecret(desKeySpec);// 加密Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");cipher.init(Cipher.ENCRYPT_MODE, convertsecretKey);String src = "加密的字符串";byte[] result = cipher.doFinal(src.getBytes());System.out.println("result des encrypt:"+ Hex.encodeHexString(result));// 解密cipher.init(Cipher.DECRYPT_MODE, convertsecretKey);result = cipher.doFinal(result);System.out.println("result des decrypt:" + new String(result));} catch (Exception e) {e.printStackTrace();}}// JDK DES算法实现private static void jdk3DES() {try {// 生成密钥KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");keyGenerator.getProvider();System.out.println(keyGenerator.getProvider());keyGenerator.init(168);SecretKey secretKey = keyGenerator.generateKey();byte[] bytesKey = secretKey.getEncoded();// key转换DESKeySpec desKeySpec = new DESKeySpec(bytesKey);SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");Key convertsecretKey = keyFactory.generateSecret(desKeySpec);// 加密Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");cipher.init(Cipher.ENCRYPT_MODE, convertsecretKey);String src = "加密的字符串";byte[] result = cipher.doFinal(src.getBytes());System.out.println("result des encrypt:"+ Hex.encodeHexString(result));// 解密cipher.init(Cipher.DECRYPT_MODE, convertsecretKey);result = cipher.doFinal(result);System.out.println("result des decrypt:" + new String(result));} catch (Exception e) {e.printStackTrace();}}private static void bc3DES() {try {Security.addProvider(new BouncyCastleProvider());// 生成密钥KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede", "BC");keyGenerator.getProvider();System.out.println(keyGenerator.getProvider());keyGenerator.init(168);SecretKey secretKey = keyGenerator.generateKey();byte[] bytesKey = secretKey.getEncoded();// key转换DESKeySpec desKeySpec = new DESKeySpec(bytesKey);SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");Key convertsecretKey = keyFactory.generateSecret(desKeySpec);// 加密Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");cipher.init(Cipher.ENCRYPT_MODE, convertsecretKey);String src = "加密的字符串";byte[] result = cipher.doFinal(src.getBytes());System.out.println("result des encrypt:"+ Hex.encodeHexString(result));// 解密cipher.init(Cipher.DECRYPT_MODE, convertsecretKey);result = cipher.doFinal(result);System.out.println("result des decrypt:" + new String(result));} catch (Exception e) {e.printStackTrace();}}}