解密微信小程序加密信息-蒲公英云

获取微信程序人员信息之后，会给一个加密字符串，这个时候，前端不太好解密，因为浪费性能，会请求后端解密，那么后端如何解密呢？demo来说话；

1、首先工具类

package com.XXX.member.utils;
import com.alibaba.fastjson.JSONObject;
import lombok.Data;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.AlgorithmParameters;
import java.security.Key;
import java.security.Security;
import java.util.Base64;
/**
 * 小程序 AES 解密工具
 *
 * @author Kilde
 */
@Data
public class WXBizDataCrypt {
//    public static void main(String[] args) {
//
//        String appId = "wx4f4bc4dec97d474b";
//        String sessionKey = "tiihtNczf5v6AKRyjwEUhQ==";
//        String encryptedData = "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";
//        String iv = "r7BXXKkLb8qrSNn05n0qiA==";
//
//        WXBizDataCrypt pc = new WXBizDataCrypt(appId,sessionKey);
//        JSONObject decrypt = pc.decrypt(encryptedData, iv);
//
//        System.out.println(decrypt.toString());
//
//    }
    public static JSONObject getMoreInfoFromEncryptedData(String appId, String sessionKey, String encryptedData, String iv) {
        WXBizDataCrypt pc = new WXBizDataCrypt(appId, sessionKey);
        JSONObject decrypt = pc.decrypt(encryptedData, iv);
        return decrypt;
    }
    private String appId;
    private String sessionKey;
    public WXBizDataCrypt(String appId, String sessionKey) {
        this.appId = appId;
        this.sessionKey = sessionKey;
    }
    /**
     * 解密成json
     *
     * @param encryptedData
     * @param iv
     * @return
     */
    public JSONObject decrypt(String encryptedData, String iv) {
        byte[] encryptedDataDecode = Base64.getDecoder().decode(encryptedData);
        byte[] sessionKeyDecode = Base64.getDecoder().decode(this.sessionKey);
        byte[] ivDecode = Base64.getDecoder().decode(iv);
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        byte[] decodeData = decode(encryptedDataDecode, sessionKeyDecode, ivDecode);
        String stringData = new String(decodeData);
        JSONObject jsonObject = JSONObject.parseObject(stringData);
        return jsonObject;
    }
    /**
     * 解密算法 AES-128-CBC
     * 填充模式 PKCS#7
     *
     * @param encryptedDataDecode 目标密文
     * @return
     * @throws Exception
     */
    private byte[] decode(byte[] encryptedDataDecode, byte[] sessionKeyDecode, byte[] iv) {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
            Key sKeySpec = new SecretKeySpec(sessionKeyDecode, "AES");
            cipher.init(Cipher.DECRYPT_MODE, sKeySpec, generateIV(iv));// 初始化
            byte[] result = cipher.doFinal(encryptedDataDecode);
            return result;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    /**
     * 处理iv
     *
     * @param iv
     * @return
     * @throws Exception
     */
    private AlgorithmParameters generateIV(byte[] iv) throws Exception {
        AlgorithmParameters params = AlgorithmParameters.getInstance("AES");
        params.init(new IvParameterSpec(iv));
        return params;
    }
}

2、真正的代码

@Transactional(rollbackFor = Exception.class)
    @Override
    public JsonResult<UserInfoVoWeChatInfoDTO> saveAcode2SessionUserInfo(UserInfoVoWeChatInfoVO userInfoVoWeChatInfoVO) {
        if (Objects.isNull(userInfoVoWeChatInfoVO)) {
            return new JsonResult(JsonResultEnum.ARGS_NOT_FULL);
        }
        String encryptedData = userInfoVoWeChatInfoVO.getEncryptedData();
        Integer flag = userInfoVoWeChatInfoVO.getFlag();
        String iv = userInfoVoWeChatInfoVO.getIv();
        String sessionKey = userInfoVoWeChatInfoVO.getSessionKey();
        String openId = userInfoVoWeChatInfoVO.getOpenId();
        if (StringUtils.isBlank(encryptedData) ||
                StringUtils.isBlank(iv) ||
                StringUtils.isBlank(sessionKey) ||
                StringUtils.isBlank(openId) ||
                Objects.isNull(flag)) {
            return new JsonResult(JsonResultEnum.ARGS_NOT_FULL);
        }
        UserInfoVo userInfoVo = UserInfoVo.builder().build();
        String userPhone = userInfoVo.getUserPhone();
        String wechatAvatar = userInfoVo.getWechatAvatar();
        String wechatNickname = userInfoVo.getWechatNickname();
        String wechatOpenid = userInfoVo.getWechatOpenid();
        /**
         * 用户信息的
         * {"country":"CN","unionId":"ocMvos6NjeKLIBqg5Mr9QjxrP1FA","watermark":{"appid":"wx4f4bc4dec97d474b","timestamp":1477314187},"gender":1,"province":"Guangdong","city":"Guangzhou","avatarUrl":"http://wx.qlogo.cn/mmopen/vi_32/aSKcBBPpibyKNicHNTMM0qJVh8Kjgiak2AHWr8MHM4WgMEm7GFhsf8OYrySdbvAMvTsw3mo8ibKicsnfN5pRjl1p8HQ/0","openId":"oGZUI0egBJY1zhBYw2KhdUfwVJJE","nickName":"Band","language":"zh_CN"}
         *
         * 手机号的
         *
         * {"phoneNumber":"186168383*2","watermark":{"appid":"wxf0e8d778d88e861b","timestamp":1598263205},"purePhoneNumber":"18616838312","countryCode":"86"}
         *
         */
        if (flag.equals(NumberUtils.INTEGER_ONE)) {
            JSONObject moreInfoFromEncryptedDataJosn =
                    WXBizDataCrypt.getMoreInfoFromEncryptedData(appid, sessionKey, encryptedData, iv);
            //优先选这个
            userPhone = String.valueOf(moreInfoFromEncryptedDataJosn.get("phoneNumber"));
            userPhone = StringUtils.isBlank(userPhone) ? String.valueOf(moreInfoFromEncryptedDataJosn.get("purePhoneNumber")) : userPhone;
            wechatOpenid = openId;
        } else if (flag.equals(NumberUtils.INTEGER_TWO)) {
            JSONObject moreInfoFromEncryptedDataJosn =
                    WXBizDataCrypt.getMoreInfoFromEncryptedData(appid, sessionKey, encryptedData, iv);
            wechatAvatar = moreInfoFromEncryptedDataJosn.getString("avatarUrl");
            wechatNickname = moreInfoFromEncryptedDataJosn.getString("nickName");
            wechatOpenid = openId;
        }
        UserInfo userInfo = userInfoMapper.selectUserInfo(openId, userPhone);
        if (Objects.isNull(userInfo)) {
            //等获取到再补充更正
            UserInfo build = UserInfo.builder()
                    .userMoney(0)
                    .userName("0")
                    .userPhone(StringUtils.isBlank(userPhone) ? "0" : userPhone)
                    .wechatNickname(StringUtils.isBlank(wechatNickname) ? "0" : wechatNickname)
                    .wechatAvatar(StringUtils.isBlank(wechatAvatar) ? "0" : wechatAvatar)
                    .wechatOpenid(openId)
                    .build();
            int i = userInfoMapper.insertUser(build);
            if (i != 1) {
                log.error("小程序获取Acode2Session信息保存失败---build:{}", JSON.toJSONString(build));
                return JsonResult.error(JsonResultEnum.EXCEPTION_ERROR.getMsg());
            }
        } else if (Objects.nonNull(userInfo) && StringUtils.isNotBlank(wechatNickname) &&  StringUtils.isNotBlank(wechatAvatar)) {
            userInfo.setUserPhone(StringUtils.isBlank(userPhone) ? "0" : userPhone);
            userInfo.setWechatNickname(wechatNickname);
            userInfo.setWechatAvatar(wechatAvatar);
            int i = userInfoMapper.updateByPrimaryKeySelective(userInfo);
            if (i != 1) {
                log.error("完善微信授权信息失败---build:{}", JSON.toJSONString(userInfo));
                return JsonResult.error(JsonResultEnum.EXCEPTION_ERROR.getMsg());
            }
        }
        if (flag.equals(NumberUtils.INTEGER_ONE)) {
            UserInfoVoWeChatInfoDTO resultObject = UserInfoVoWeChatInfoDTO.builder()
                    .phone(userPhone)
                    .openId(openId)
                    .build();
            return new JsonResult(JsonResultEnum.SUCCESS, resultObject);
        } else if (flag.equals(NumberUtils.INTEGER_TWO)) {
            UserInfoVoWeChatInfoDTO resultObject = UserInfoVoWeChatInfoDTO.builder().phone(userPhone)
                    .wechatAvatar(wechatAvatar)
                    .wechatNickname(wechatNickname)
                    .phone(userInfo.getUserPhone())
                    .openId(openId).build();
            return new JsonResult(JsonResultEnum.SUCCESS, resultObject);
        }
        return JsonResult.seccess();
    }