<span style="font-family:Comic Sans MS;"><span style="font-size:12px;">package com.sica.des;
import com.google.common.base.Strings;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
/**
* Created by xiang.li on 2015/2/28.
* DES 加解密工具类
*
* <pre>
* 支持 DES、DESede(TripleDES,就是3DES)、AES、Blowfish、RC2、RC4(ARCFOUR)
* DES key size must be equal to 56
* DESede(TripleDES) key size must be equal to 112 or 168
* AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
* Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
* RC2 key size must be between 40 and 1024 bits
* RC4(ARCFOUR) key size must be between 40 and 1024 bits
* 具体内容 需要关注 JDK Document http://.../docs/technotes/guides/security/SunProviders.html
* </pre>
*/
public class DES {
/**
* 定义加密方式
*/
private final static String KEY_DES = "DES";
private final static String KEY_AES = "AES"; // 测试
/**
* 全局数组
*/
private final static String[] hexDigits = { "0", "1", "2", "3", "4", "5",
"6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
/**
* 初始化密钥
* @return
*/
public static String init() {
return init(null);
}
/**
* 初始化密钥
* @param seed 初始化参数
* @return
*/
public static String init(String seed) {
SecureRandom secure = null;
String str = "";
try {
if (null != secure) {
// 带参数的初始化
secure = new SecureRandom(decryptBase64(seed));
} else {
// 不带参数的初始化
secure = new SecureRandom();
}
KeyGenerator generator = KeyGenerator.getInstance(KEY_DES);
generator.init(secure);
SecretKey key = generator.generateKey();
str = encryptBase64(key.getEncoded());
} catch (Exception e) {
e.printStackTrace();
}
return str;
}
/**
* 转换密钥
* @param key 密钥的字节数组
* @return
*/
private static Key byteToKey(byte[] key) {
SecretKey secretKey = null;
try {
DESKeySpec dks = new DESKeySpec(key);
SecretKeyFactory factory = SecretKeyFactory.getInstance(KEY_DES);
secretKey = factory.generateSecret(dks);
// 当使用其他对称加密算法时，如AES、Blowfish等算法时，用下述代码替换上述三行代码
// secretKey = new SecretKeySpec(key, KEY_DES);
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
return secretKey;
}
/**
* DES 解密
* @param data 需要解密的字符串
* @param key 密钥
* @return
*/
public static String decryptDES(String data, String key) {
// 验证传入的字符串
if (Strings.isNullOrEmpty(data)) {
return "";
}
// 调用解密方法完成解密
byte[] bytes = decryptDES(hexString2Bytes(data), key);
// 将得到的字节数组变成字符串返回
return new String(bytes);
}
/**
* DES 解密
* @param data 需要解密的字节数组
* @param key 密钥
* @return
*/
public static byte[] decryptDES(byte[] data, String key) {
byte[] bytes = null;
try {
Key k = byteToKey(decryptBase64(key));
Cipher cipher = Cipher.getInstance(KEY_DES);
cipher.init(Cipher.DECRYPT_MODE, k);
bytes = cipher.doFinal(data);
} catch (Exception e) {
e.printStackTrace();
}
return bytes;
}
/**
* DES 加密
* @param data 需要加密的字符串
* @param key 密钥
* @return
*/
public static String encryptDES(String data, String key) {
// 验证传入的字符串
if (Strings.isNullOrEmpty(data)) {
return "";
}
// 调用加密方法完成加密
byte[] bytes = encryptDES(data.getBytes(), key);
// 将得到的字节数组变成字符串返回
return byteArrayToHexString(bytes);
}
/**
* DES 加密
* @param data 需要加密的字节数组
* @param key 密钥
* @return
*/
public static byte[] encryptDES(byte[] data, String key) {
byte[] bytes = null;
try {
Key k = byteToKey(decryptBase64(key));
Cipher cipher = Cipher.getInstance(KEY_DES);
cipher.init(Cipher.ENCRYPT_MODE, k);
bytes = cipher.doFinal(data);
} catch (Exception e) {
e.printStackTrace();
}
return bytes;
}
/**
* BASE64 解密
* @param key 需要解密的字符串
* @return 字节数组
* @throws Exception
*/
public static byte[] decryptBase64(String key) throws Exception {
return (new BASE64Decoder()).decodeBuffer(key);
}
/**
* BASE64 加密
* @param key 需要加密的字节数组
* @return 字符串
* @throws Exception
*/
public static String encryptBase64(byte[] key) throws Exception {
return (new BASE64Encoder()).encodeBuffer(key);
}
/**
* 将一个字节转化成十六进制形式的字符串
* @param b 字节数组
* @return 字符串
*/
private static String byteToHexString(byte b) {
int ret = b;
//System.out.println("ret = " + ret);
if (ret < 0) {
ret += 256;
}
int m = ret / 16;
int n = ret % 16;
return hexDigits[m] + hexDigits[n];
}
/**
* 转换字节数组为十六进制字符串
* @param bytes 字节数组
* @return 十六进制字符串
*/
private static String byteArrayToHexString(byte[] bytes) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < bytes.length; i++) {
sb.append(byteToHexString(bytes[i]));
}
return sb.toString();
}
/**
* 转换十六进制字符串为字节数组
* @param hexstr 十六进制字符串
* @return
*/
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;
}
/**
* 转换字符类型数据为整型数据
* @param c 字符
* @return
*/
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;
}
/**
* 测试方法
* @param args
*/
public static void main(String[] args) {
String key = DES.init();
System.out.println("DES密钥:\n" + key);
String word = "123";
String encWord = encryptDES(word, key);
System.out.println(word + "\n加密后：\n" + encWord);
System.out.println(word + "\n解密后：\n" + decryptDES(encWord, key));
}
}</span><span style="font-size: 14px;">
</span></span>原文地址：http://blog.csdn.net/happylee6688/article/details/44455407
