簡單加密/解密方法包裝, 含encode(),decode(),md5() (轉)

簡單加密/解密方法包裝, 含encode(),decode(),md5() (轉)[@more@]

package steeven;

/*
用途: 簡單/方法包裝
作者: steeven@kali.com.cn
日期: 12/05/2001
感謝: Java/l-security/index.shtml">http://www-900.ibm.com/developerWorks/java/l-security/index.shtml

說明:
This Class need JCE, here:
http://java.sun.com/security/index.html

*/

import java.security.*;
import javax.crypto.*;
public class Crypt {

 private static String Algorithm="DES"; //定義 加密演算法,可用 DES,DESede,Blowfish

 static boolean de = false;

 static{
 Security.addProvr(new com.sun.crypto.provider.SunJCE());
 }

 //生成金鑰, 注意此步驟時間比較長
 public static byte[] getKey() throws Exception{
 KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);
 SecretKey deskey = keygen.generateKey();
 if (debug)
 System.out.println("生成金鑰:"+byte2hex(deskey.getEncoded()));
 return deskey.getEncoded();
 }

 //加密
 public static byte[] encode(byte[] input,byte[] key) throws Exception{
 SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key,Algorithm);
 if (debug){
 System.out.println("加密前的二進串:"+byte2hex(input));
 System.out.println("加密前的字串:"+new String(input));
 }
 Cipher c1 = Cipher.getInstance(Algorithm);
 c1.init(Cipher.ENCRYPT_MODE,deskey);
 byte[] cipherByte=c1.doFinal(input);
 if (debug)
 System.out.println("加密後的二進串:"+byte2hex(cipherByte));
 return cipherByte;
 }

 //解密
 public static byte[] decode(byte[] input,byte[] key) throws Exception{
 SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key,Algorithm);
 if (debug)
 System.out.println("解密前的資訊:"+byte2hex(input));
 Cipher c1 = Cipher.getInstance(Algorithm);
 c1.init(Cipher.DECRYPT_MODE,deskey);
 byte[] clearByte=c1.doFinal(input);
 if (debug){
 System.out.println("解密後的二進串:"+byte2hex(clearByte));
 System.out.println("解密後的字串:"+(new String(clearByte)));
 }
 return clearByte;
 }

 //md5()資訊摘要, 不可逆
 public static byte[] md5(byte[] input) throws Exception{
 java.security.MessageDigest alg=java.security.MessageDigest.getInstance("MD5"); //or "SHA-1"
 if (debug){
 System.out.println("摘要前的二進串:"+byte2hex(input));
 System.out.println("摘要前的字串:"+new String(input));
 }
 alg.update(input);
 byte[] digest = alg.digest();
 if (debug)
 System.out.println("摘要後的二進串:"+byte2hex(digest));
 return digest;
 }

 //位元組碼轉換成16進位制字串
 public static String byte2hex(byte[] b) {
 String hs="";
 String stmp="";
 for (int n=0;n stmp=(java.lang.Integer.toHexString(b[n] & 0XFF));
 if (stmp.length()==1)
 hs=hs+"0"+stmp;
 else hs=hs+stmp;
 if (n }
 return hs.toUpperCase();
 }

 public static void main(String[] args) throws Exception{
 debug = true;
// byte[] key = getKey();
 byte[] key = "好好學習".getBytes();
 decode(encode("測試加密".getBytes(),key),key);
 md5("測試加密".getBytes());
 }
}