java密码加密与解密

以下两个类可以很方便的完成字符串的加密和解密：

加密：CryptHelper.encrypt(password)

解密：CrypHelper.decrypt(password)

代码如下：

CryptUtils.java

[java]
package com.gdie.lab.crypt;

import java.io.IOException;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;

public class CryptUtils {
    private static String Algorithm = "DES";
    private static byte[] DEFAULT_KEY=new byte[] {-53, 122, -42, -88, -110, -123, -60, -74};
    private static String VALUE_ENCODING="UTF-8";


    /**
     * 生成密钥
     *
     * @return byte[] 返回生成的密钥
     * @throws exception
     *             扔出异常.
     */
    public static byte[] getSecretKey() throws Exception {
        KeyGenerator keygen = KeyGenerator.getInstance(Algorithm);
        SecretKey deskey = keygen.generateKey();
        // if (debug ) System.out.println ("生成密钥:"+byte2hex (deskey.getEncoded
        // ()));
        return deskey.getEncoded();

    }

    /**
     * 将指定的数据根据提供的密钥进行加密
     *
     * @param input
     *            需要加密的数据
     * @param key
     *            密钥
     * @return byte[] 加密后的数据
     * @throws Exception
     */
    public static byte[] encryptData(byte[] input, byte[] key) throws Exception {
        SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key, Algorithm);
        // if (debug )
        // {
        // System.out.println ("加密前的二进串:"+byte2hex (input ));
        // System.out.println ("加密前的字符串:"+new String (input ));
        //
        // }
        Cipher c1 = Cipher.getInstance(Algorithm);
        c1.init(Cipher.ENCRYPT_MODE, deskey);
        byte[] cipherByte = c1.doFinal(input);
        // if (debug ) System.out.println ("加密后的二进串:"+byte2hex (cipherByte ));
        return cipherByte;

    }

    public static byte[] encryptData(byte[] input) throws Exception {
        return encryptData(input, DEFAULT_KEY);
    }

    /**
     * 将给定的已加密的数据通过指定的密钥进行解密
     *
     * @param input
     *            待解密的数据
     * @param key
     *            密钥
     * @return byte[] 解密后的数据
     * @throws Exception
     */
    public static byte[] decryptData(byte[] input, byte[] key) throws Exception {
        SecretKey deskey = new javax.crypto.spec.SecretKeySpec(key, Algorithm);
        // if (debug ) System.out.println ("解密前的信息:"+byte2hex (input ));
        Cipher c1 = Cipher.getInstance(Algorithm);
        c1.init(Cipher.DECRYPT_MODE, deskey);
        byte[] clearByte = c1.doFinal(input);
        // if (debug )
        // {
        // System.out.println ("解密后的二进串:"+byte2hex (clearByte ));
        // System.out.println ("解密后的字符串:"+(new String (clearByte )));
        //
        // }
        return clearByte;

    }

    public static byte[] decryptData(byte[] input) throws Exception {
        return decryptData(input, DEFAULT_KEY);
    }

    /**
     * 字节码转换成16进制字符串
     *
     * @param byte[] b 输入要转换的字节码
     * @return String 返回转换后的16进制字符串
     */
    public static String byte2hex(byte[] bytes) {
        StringBuilder hs = new StringBuilder();
        for(byte b : bytes)
            hs.append(String.format("%1$02X", b));
        return hs.toString();
    }

    public static byte[] hex2byte(String content) {
        int l=content.length()>>1;
        byte[] result=new byte[l];
        for(int i=0;i<l;i++) {
            int j=i<<1;
            String s=content.substring(j, j+2);
            result[i]=Integer.valueOf(s, 16).byteValue();
        }
        return result;
    }&nbs

补充：综合编程 , 安全编程 ,