package com.ltkj.web.controller.mall;

import com.ltkj.web.controller.system.AES;
import org.apache.commons.codec.binary.Base64;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

/**
 * 封装对外访问方法
 */
public class WXCore {

    private static final String WATERMARK = "watermark";
    private static final String APPID = "appid";

    /**
     * 解密数据
     *
     * @return
     * @throws Exception
     */
    public static String decrypt(String appId, String encryptedData, String sessionKey, String iv) {
        String result = "";
        try {
            AES aes = new AES();
            byte[] resultByte = aes.decrypt(Base64.decodeBase64(encryptedData), Base64.decodeBase64(sessionKey),
                    Base64.decodeBase64(iv));
            if (null != resultByte && resultByte.length > 0) {
                result = new String(WxPKCS7Encoder.decode(resultByte));
                JSONObject jsonObject = JSON.parseObject(result);
                String decryptAppid = jsonObject.getJSONObject(WATERMARK).getString(APPID);
                if (!appId.equals(decryptAppid)) {
                    result = "";
                }
            }
        } catch (Exception e) {
            result = "";
            e.printStackTrace();
        }
        return result;
    }


}