/*
* Copyright 2015 Rocko (http://rocko.xyz) <rocko.zxp@gmail.com>.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package xyz.rocko.security.security.util;
import java.io.UnsupportedEncodingException;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
/**
* AES 对称加密
*/
public class AESUtils {
/**
* 算法/模式/填充 *
*/
private static final String CipherMode = "AES";
/**
* 创建密钥
*
* @param password 例如:"0123456701234567" 128位 16*8 <br>
* 所有密钥长度不能超过16字符中文占两个。192 24; 256 32
* @return SecretKeySpec 实例
*/
private static SecretKeySpec generateAESKey(String password) {
byte[] data = null;
StringBuilder sb = new StringBuilder();
sb.append(password);
while (sb.length() < 16)
sb.append("0");
if (sb.length() > 16)
sb.setLength(16);
try {
data = sb.toString().getBytes("UTF-8");
return new SecretKeySpec(data, "AES");
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 加密字节数据
*
* @param content 需要加密的字节数组
* @param password 密钥 128 <16个字节 192 <24,256 <32个字节
* @return 加密完后的字节数组
*/
public static byte[] encryptData(byte[] content, String password) {
try {
SecretKeySpec key = generateAESKey(password);
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] result = cipher.doFinal(content);
return result;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 加密(结果为16进制字符串), UTF-8 编码
*
* @param content 要加密的字符串
* @param password 密钥
* @return 加密后的16进制字符串
*/
public static String encryptData(String content, String password) {
byte[] data = null;
try {
data = content.getBytes("UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
data = encryptData(data, password);
String result = byte2hex(data);
return result;
}
/**
* 解密字节数组 UTF-8
*
* @param content
* @param password
* @return
*/
public static byte[] decryptData(byte[] content, String password) {
try {
SecretKeySpec key = generateAESKey(password);
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.DECRYPT_MODE, key);
return cipher.doFinal(content);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 解密16进制的字符串为字符串 *
*/
public static String decryptData(String content, String password) {
byte[] data = null;
try {
data = hex2byte(content);
} catch (Exception e) {
e.printStackTrace();
}
data = decryptData(data, password);
if (data == null)
return null;
String result = null;
try {
result = new String(data, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}
/**
* 字节数组转成16进制字符串
*
* @param b
* @return 16进制字符串
*/
public static String byte2hex(byte[] b) { // 一个字节的数,
StringBuffer sb = new StringBuffer(b.length * 2);
String tmp = "";
for (int n = 0; n < b.length; n++) {
// 整数转成十六进制表示
tmp = (Integer.toHexString(b[n] & 0XFF));
if (tmp.length() == 1) {
sb.append("0");
}
sb.append(tmp);
}
return sb.toString().toUpperCase(); // 转成大写
}
/**
* 将hex字符串转换成字节数组 *
*
* @param inputString 16进制的字符串
* @return 字节数组
*/
public static byte[] hex2byte(String inputString) {
if (inputString == null || inputString.length() < 2) {
return new byte[0];
}
inputString = inputString.toLowerCase();
int l = inputString.length() / 2;
byte[] result = new byte[l];
for (int i = 0; i < l; ++i) {
String tmp = inputString.substring(2 * i, 2 * i + 2);
result[i] = (byte) (Integer.parseInt(tmp, 16) & 0xFF);
}
return result;
}
}