package com.yx.nrs;
import java.io.UnsupportedEncodingException;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
/**
* Created by 雨夏 on 2018/5/25.
*/
public class AES {
// private static final String CipherMode = "AES/ECB/PKCS5Padding";使用ECB加密，不需要设置IV，但是不安全
private static final String CipherMode = "AES/CFB/NoPadding";//使用CFB加密，需要设置IV
// /** 创建密钥 **/
private static SecretKeySpec createKey(String password) {
byte[] data = null;
if (password == null) {
password = "";
}
StringBuilder sb = new StringBuilder(32);
sb.append(password);
while (sb.length() < 32) {
sb.append("0");
}
if (sb.length() > 32) {
sb.setLength(32);
}
try {
data = sb.toString().getBytes("UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return new SecretKeySpec(data, "AES");
}
// /** 加密字节数据 **/
private static byte[] encrypt(byte[] content, String password) {
try {
SecretKeySpec key = createKey(password);
System.out.println(key);
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(
new byte[cipher.getBlockSize()]));
return cipher.doFinal(content);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
// /** 加密(结果为16进制字符串) **/
public static String encrypt(String password,String content ) {
//Log.d("加密前","seed="+password+"\ncontent="+content);
byte[] data = null;
try {
data = content.getBytes("UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
data = encrypt(data, password);
String result = byte2hex(data);
//Log.d("加密后","result="+result);
return result;
}
// /** 解密字节数组 **/
private static byte[] decrypt(byte[] content, String password) {
try {
SecretKeySpec key = createKey(password);
Cipher cipher = Cipher.getInstance(CipherMode);
cipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(
new byte[cipher.getBlockSize()]));
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 decrypt(String password,String content) {
//Log.d("解密前","seed="+password+"\ncontent="+content);
byte[] data = null;
try {
data = hex2byte(content);
} catch (Exception e) {
e.printStackTrace();
}
data = decrypt(data, password);
if (data == null)
return null;
String result = null;
try {
result = new String(data, "UTF-8");
//Log.d("解密后","result="+result);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return result;
}
// /** 字节数组转成16进制字符串 **/
private static String byte2hex(byte[] b) { // 一个字节的数，
StringBuilder sb = new StringBuilder(b.length * 2);
String tmp = "";
for (byte aB : b) {
// 整数转成十六进制表示
tmp = (Integer.toHexString(aB & 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 **/
private 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;
}
}
