DES加密实例
最近在学习加密解密的相关知识，为了加强记忆，参照一些资料写了些简单的加解密实现。写不好，欢迎大家拍砖和指教。
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DES加密实例
package com.royboy.encrypt;import java.io.BufferedInputStream;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileWriter;import java.io.IOException;import java.security.NoSuchAlgorithmException;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import com.sun.org.apache.xml.internal.security.utils.Base64;public class DesTester {public final static String FILEPATH = "C:\\BitIO.txt";public static byte[] data ;/** * 生成密钥 * @return 密钥内容 * @throws NoSuchAlgorithmException */public void generateKey() throws NoSuchAlgorithmException {//实例化密钥生成器KeyGenerator kg = KeyGenerator.getInstance("DES");//初始化kg.init(56);//生成密钥SecretKey secretKey = kg.generateKey();//获得二进制编码的密钥byte[] b = secretKey.getEncoded();/* * 将密钥写入到文件中 * */File fileInst = new File(FILEPATH);try {if (!fileInst.exists())fileInst.createNewFile();FileWriter fw = new FileWriter(fileInst);//对生成的密钥进行了BASE64加密String keyEncode = Base64.encode(b);System.out.println("生成的密钥:"+keyEncode);fw.write(keyEncode);fw.flush();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException ioe) {ioe.printStackTrace();}}private byte[] getKey() {byte[] content = null;try {File fileInst = new File(FILEPATH);BufferedInputStream in = new BufferedInputStream(new FileInputStream(fileInst));ByteArrayOutputStream out = new ByteArrayOutputStream(1024);byte[] temp = new byte[1024];int size = 0;while ((size = in.read(temp)) != -1) {out.write(temp, 0, size);}in.close();content = out.toByteArray();content = Base64.decode(content);} catch(IOException ioe){ioe.printStackTrace();}catch (Exception e) {e.printStackTrace();}return content;}/** * DES数据加密 * @return 加密后的数据(用户base64进行了编码) */private String encryptData(){byte[] encrypt =null;byte[] sk = getKey();try {//实例化密钥材料DESKeySpec dks = new DESKeySpec(sk);//实例化秘密密钥工厂SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");//生成秘密密钥SecretKey secretKey = keyFactory.generateSecret(dks);//实例化Cipher cipher = Cipher.getInstance("DES");//实始化，设置为加密模式cipher.init(Cipher.ENCRYPT_MODE, secretKey);//执行加密操作encrypt = cipher.doFinal(data);} catch (Exception e) {}//对加密后的内容进行了BASE64编码。非必须，对于网络传送数据来说，二进制更为理想String encryptStr = Base64.encode(encrypt);System.out.println("加密后的数据(base64):"+encryptStr);return encryptStr;}/** * DES数据解密 * @param d 需要解密的数据 * @return 解密后的数据 */private byte[] decryptData(String encryptStr){byte[] decrypt =null;/* * 得到密钥材料 * */byte[] sk = getKey();try {//实例化密钥材料DESKeySpec dks = new DESKeySpec(sk);//实例化秘密密钥工厂SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");//生成秘密密钥SecretKey secretKey = keyFactory.generateSecret(dks);//实例化Cipher cipher = Cipher.getInstance("DES");//实始化，设置为解密模式cipher.init(Cipher.DECRYPT_MODE, secretKey);//执行解密操作decrypt = cipher.doFinal(Base64.decode(encryptStr));} catch (Exception e) {}return decrypt;}/** * DES加密测试方法 * @param dataStr 要加密的原始内容 * @throws Exception */public void desTest(String dataStr) throws Exception{System.out.println("=====DES=====");System.out.println("原始数据:"+dataStr);data = dataStr.getBytes();generateKey();System.out.println("解密后的数据(string):"+new String(decryptData(encryptData())));System.out.println("=====DES=====");}public static void main(String[] args) throws Exception{DesTester dt = new DesTester();dt.desTest("中华人民共和国");}}?