常用对称加密算法-DES

来源：互联网发布：老王python视频教程编辑：程序博客网时间：2024/06/05 20:07
详细介绍：http://blog.csdn.net/cc41798520101/article/details/53673681
package com.test;import java.security.Key;import java.security.SecureRandom;import javax.crypto.Cipher;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import org.apache.commons.codec.binary.Base64;public class DESUtil {//算法名称     public static final String KEY_ALGORITHM = "DES";    //算法名称/加密模式/填充方式     //DES共有四种工作模式-->>ECB：电子密码本模式、CBC：加密分组链接模式、CFB：加密反馈模式、OFB：输出反馈模式    //public static final String CIPHER_ALGORITHM = "DES/ECB/NoPadding";    public static final String CIPHER_ALGORITHM = "DES/ECB/PKCS5Padding";    //KEY    //public static final String KEY = "A1B2C3D4E5F60708";    public static final String KEY = "wadasdsadasdaadsaas";    /**      * 加密数据     * @param data 待加密数据     * @param key 密钥     * @return 加密后的数据      */    /*public static String encrypt(String data, String key) throws Exception {        Key deskey = keyGenerator(key);*/    public static String encrypt(String data) throws Exception {        Key deskey = keyGenerator(DESUtil.KEY);        // 实例化Cipher对象，它用于完成实际的加密操作        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);        SecureRandom random = new SecureRandom();        // 初始化Cipher对象，设置为加密模式        cipher.init(Cipher.ENCRYPT_MODE, deskey, random);        byte[] results = cipher.doFinal(data.getBytes("utf-8"));        // 执行加密操作。加密后的结果通常都会用Base64编码进行传输         return Base64.encodeBase64String(results);    }    /**      * 解密数据      * @param data 待解密数据      * @param key 密钥      * @return 解密后的数据      */    /*public static String decrypt(String data, String key) throws Exception {    Key deskey = keyGenerator(key);*/    public static String decrypt(String data) throws Exception {        Key deskey = keyGenerator(DESUtil.KEY);        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);        //初始化Cipher对象，设置为解密模式        cipher.init(Cipher.DECRYPT_MODE, deskey);        // 执行解密操作        return new String(cipher.doFinal(Base64.decodeBase64(data)));    }        /**     *        * 生成密钥key对象     * @param KeyStr 密钥字符串      * @return 密钥对象      * @throws InvalidKeyException        * @throws NoSuchAlgorithmException        * @throws InvalidKeySpecException        * @throws Exception      */    private static SecretKey keyGenerator(String keyStr) throws Exception {        //byte input[] = hexString2Bytes(keyStr);    byte input[] = keyStr.getBytes();        DESKeySpec desKey = new DESKeySpec(input);        //创建一个密匙工厂，然后用它把DESKeySpec转换成SecretKey        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");        SecretKey securekey = keyFactory.generateSecret(desKey);        return securekey;    }        // 从十六进制字符串到字节数组转换     public static byte[] hexString2Bytes(String hexstr) {        byte[] b = new byte[hexstr.length() / 2];        int j = 0;        for (int i = 0; i < b.length; i++) {            char c0 = hexstr.charAt(j++);            char c1 = hexstr.charAt(j++);            b[i] = (byte) ((parse(c0) << 4) | parse(c1));        }        return b;    }        private static int parse(char c) {        if (c >= 'a') return (c - 'a' + 10) & 0x0f;        if (c >= 'A') return (c - 'A' + 10) & 0x0f;        return (c - '0') & 0x0f;    }}
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