每日随笔——工厂方法模式
[实验任务一]：加密算法
目前常用的加密算法有DES（Data Encryption Standard）和IDEA（International Data Encryption Algorithm）国际数据加密算法等，请用工厂方法实现加密算法系统。
实验要求：
1.画出对应的类图；
2.提交该系统的代码，该系统务必是一个可以能够直接使用的系统，查阅资料完成相应加密算法的实现；
3.注意编程规范。
源代码：
Test1 package test; import java.util.Scanner; public class test1{ 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: { des.work("1787878787878787", "0E329232EA6D0D73"); break; } case 2: { idea.work("8787878787878787", "0E329232EA6D0D73"); break; } } } } catch (Exception e) { System.out.println(e.getMessage()); } } } Method
package test; public interface Method { public abstract void work(String str, String password); } MethodFactory
package test; public interface MethodFactory { public Method produceMethod(); } DES
package test; 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 = "信2105-3 20213892 刘家诚"; // 要加密的明文 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(); } } public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("DES加密算法"); DES des = new DES(); try { des.work("8787878787878787", "0E329232EA6D0D73"); } catch (Exception e) { System.out.println(e.getMessage()); } } } DES Factory
package test; public class DESFactory implements MethodFactory { public DES produceMethod() { System.out.println("使用DES算法"); return new DES(); } } IDEA
package test; 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; import java.util.Scanner; 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 = "20213892刘家诚"; 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); } public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("IDEA加密算法"); IDEA idea = new IDEA(); try { idea.work("8787878787878787", "0E329232EA6D0D73"); } catch (Exception e) { System.out.println(e.getMessage()); } } } IDEAFastory
package test; public class IDEAFactory implements MethodFactory { public IDEA produceMethod() { System.out.println("使用IDEA算法"); return new IDEA(); } }
