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); } }