目前常用的加密算法有 DES(Data Encryption Standard) 和 IDEA(International Data Encryption Algorithm) 国际数据加密算法, 我现在使用工厂方法模式来实现加密算法系统.
main.java
- import java.util.Scanner;
- public class main {
- public static void main(String[] args) {
- DES des=new DES();
- IDEA idea=new IDEA();
- try {
- int n = 0;
- Scanner in = new Scanner(System.in);
- while (n != 3) {
- System.out.println("请选择要使用的加密算法 1.DES 加密算法 2.IDEA 加密算法");
- System.out.println("3. 退出");
- System.out.println("请选择:");
- if (in.hasNextInt()) {
- n = in.nextInt();
- } else {
- System.out.println("输入的不是整数, 请重新输入:");
- continue;
- }
- switch (n) {
- case 1: {
- String a;
- Scanner in1 = new Scanner(System.in);
- System.out.println("选择加密文件:");
- a = in1.nextLine();
- des.work("1787878787878787","0E329232EA6D0D73",a);
- break;
- }
- case 2: {
- String b;
- Scanner in2 = new Scanner(System.in);
- System.out.println("选择加密文件:");
- b = in2.nextLine();
- idea.work("8787878787878787","0E329232EA6D0D73",b);
- break;
- }
- }
- }
- }
- catch(Exception e)
- {
- System.out.println(e.getMessage());
- }
- }
- }
主界面用于调用 Method 接口下的 DES.java 和 IDEA.java
Method.java
- public interface Method {
- public abstract void work(String str,String password,String codeStringBegin);
- }
DES.java
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- public class DES implements Method {
- public void work(String str,String password,String codeStringBegin) {
- String codeStringEnd=null; // 加密后的密文
- String decodeString=null; // 密文解密后得到的明文
- System.out.println("要加密的明文:"+codeStringBegin);
- String cipherType = "DESede"; // 加密算法类型, 可设置为 DES,DESede,AES 等字符串
- try
- {
- // 获取密钥生成器
- KeyGenerator keyGen=KeyGenerator.getInstance(cipherType);
- // 初始化密钥生成器, 不同的加密算法其密钥长度可能不同
- keyGen.init(112);
- // 生成密钥
- SecretKey key=keyGen.generateKey();
- // 得到密钥字节码
- byte[] keyByte=key.getEncoded();
- // 输出密钥的字节码
- System.out.println("密钥是:");
- for(int i=0;i<keyByte.length;i++)
- {
- System.out.print(keyByte[i]+",");
- }
- System.out.println("");
- // 创建密码器
- Cipher cp=Cipher.getInstance(cipherType);
- // 初始化密码器
- cp.init(Cipher.ENCRYPT_MODE,key);
- System.out.println("要加密的字符串是:"+ codeStringBegin);
- byte[] codeStringByte=codeStringBegin.getBytes("UTF8");
- System.out.println("要加密的字符串对应的字节码是:");
- for(int i=0;i<codeStringByte.length;i++)
- {
- System.out.print(codeStringByte[i]+",");
- }
- System.out.println("");
- // 开始加密
- byte[] codeStringByteEnd=cp.doFinal(codeStringByte);
- System.out.println("加密后的字符串对应的字节码是:");
- for(int i=0;i<codeStringByteEnd.length;i++)
- {
- System.out.print(codeStringByteEnd[i]+",");
- }
- System.out.println("");
- codeStringEnd=new String(codeStringByteEnd);
- System.out.println("加密后的字符串是:" + codeStringEnd);
- System.out.println("");
- // 重新初始化密码器
- cp.init(Cipher.DECRYPT_MODE,key);
- // 开始解密
- byte[] decodeStringByteEnd=cp.doFinal(codeStringByteEnd);
- System.out.println("解密后的字符串对应的字节码是:");
- for(int i=0;i<decodeStringByteEnd.length;i++)
- {
- System.out.print(decodeStringByteEnd[i]+",");
- }
- System.out.println("");
- decodeString=new String(decodeStringByteEnd);
- System.out.println("解密后的字符串是:" + decodeString);
- System.out.println("");
- }
- catch(Exception e)
- {
- e.printStackTrace();
- }
- }
- }
IDEA.java
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- import org.apache.commons.codec.binary.Base64;
- import org.bouncycastle.jce.provider.BouncyCastleProvider;
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- import javax.crypto.spec.SecretKeySpec;
- import java.security.Key;
- import java.security.Security;
- public class IDEA implements Method{
- public static final String KEY_ALGORITHM="IDEA";
- public static final String CIPHER_ALGORITHM="IDEA/ECB/ISO10126Padding";
- public static byte[] initkey() throws Exception{
- // 加入 bouncyCastle 支持
- Security.addProvider(new BouncyCastleProvider());
- // 实例化密钥生成器
- KeyGenerator kg=KeyGenerator.getInstance(KEY_ALGORITHM);
- // 初始化密钥生成器, IDEA 要求密钥长度为 128 位
- kg.init(128);
- // 生成密钥
- SecretKey secretKey=kg.generateKey();
- // 获取二进制密钥编码形式
- return secretKey.getEncoded();
- }
- /**
- * 转换密钥
- * @param key 二进制密钥
- * @return Key 密钥
- * */
- private static Key toKey(byte[] key) throws Exception{
- // 实例化 DES 密钥
- // 生成密钥
- SecretKey secretKey=new SecretKeySpec(key,KEY_ALGORITHM);
- return secretKey;
- }
- /**
- * 加密数据
- * @param data 待加密数据
- * @param key 密钥
- * @return byte[] 加密后的数据
- * */
- private static byte[] encrypt(byte[] data,byte[] key) throws Exception{
- // 加入 bouncyCastle 支持
- Security.addProvider(new BouncyCastleProvider());
- // 还原密钥
- Key k=toKey(key);
- // 实例化
- Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);
- // 初始化, 设置为加密模式
- cipher.init(Cipher.ENCRYPT_MODE, k);
- // 执行操作
- return cipher.doFinal(data);
- }
- /**
- * 解密数据
- * @param data 待解密数据
- * @param key 密钥
- * @return byte[] 解密后的数据
- * */
- private static byte[] decrypt(byte[] data,byte[] key) throws Exception{
- // 加入 bouncyCastle 支持
- Security.addProvider(new BouncyCastleProvider());
- // 还原密钥
- Key k =toKey(key);
- Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);
- // 初始化, 设置为解密模式
- cipher.init(Cipher.DECRYPT_MODE, k);
- // 执行操作
- return cipher.doFinal(data);
- }
- public static String getKey(){
- String result = null;
- try {
- result = Base64.encodeBase64String(initkey());
- } catch (Exception e) {
- e.printStackTrace();
- }
- return result;
- }
- public static String ideaEncrypt(String data, String key) {
- String result = null;
- try {
- byte[] data_en = encrypt(data.getBytes(), Base64.decodeBase64(key));
- result = Base64.encodeBase64String(data_en);
- } catch (Exception e) {
- e.printStackTrace();
- }
- return result;
- }
- public static String ideaDecrypt(String data, String key) {
- String result = null;
- try {
- byte[] data_de =decrypt(Base64.decodeBase64(data), Base64.decodeBase64(key));;
- result = new String(data_de);
- } catch (Exception e) {
- e.printStackTrace();
- }
- return result;
- }
- public void work(String str,String password,String data) {
- String key = getKey();
- System.out.println("要加密的原文:"+data);
- System.out.println("密钥:" + key);
- String data_en = ideaEncrypt(data, key);
- System.out.println("密文:"+data_en);
- String data_de = ideaDecrypt(data_en, key);
- System.out.println("原文:"+data_de);
- }
- }
来源: http://www.bubuko.com/infodetail-3253816.html