package com.king.weixin.util;

import java.io.UnsupportedEncodingException;

import java.security.AlgorithmParameters;

import java.security.InvalidAlgorithmParameterException;

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.security.NoSuchProviderException;

import java.security.SecureRandom;

import java.security.Security;

import java.security.spec.InvalidParameterSpecException;

import java.util.Arrays;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.KeyGenerator;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.SecretKey;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import org.codehaus.xfire.util.Base64;

import net.sf.json.JSONObject;

public class AesUtil

{

/**

* 解密encryptedData获取用户信息

*/

public JSONObject getUserInfo(String encryptedData,String sessionkey,String iv){

// 被加密的数据

byte[] dataByte = Base64.decode(encryptedData);

// 加密秘钥

byte[] keyByte = Base64.decode(sessionkey);

// 偏移量

byte[] ivByte = Base64.decode(iv);

try {

// 如果密钥不足16位，那么就补足. 这个if 中的内容很重要

int base = 16;

if (keyByte.length % base != 0) {

int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);

byte[] temp = new byte[groups * base];

Arrays.fill(temp, (byte) 0);

System.arraycopy(keyByte, 0, temp, 0, keyByte.length);

keyByte = temp;

}

// 初始化

Security.addProvider(new BouncyCastleProvider());

Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");

SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");

AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");

parameters.init(new IvParameterSpec(ivByte));

cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化

byte[] resultByte = cipher.doFinal(dataByte);

if (null != resultByte && resultByte.length > 0) {

String result = new String(resultByte, "UTF-8");

return JSONObject.fromObject(result);

}

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

} catch (NoSuchPaddingException e) {

e.printStackTrace();

} catch (InvalidParameterSpecException e) {

e.printStackTrace();

} catch (IllegalBlockSizeException e) {

e.printStackTrace();

} catch (BadPaddingException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (InvalidKeyException e) {

e.printStackTrace();

} catch (InvalidAlgorithmParameterException e) {

e.printStackTrace();

} catch (NoSuchProviderException e) {

e.printStackTrace();

}

return null;

}

}