委托代扣解约成功通知(JSON)

签约、解约成功后（包含用户主动解约），微信会把相关签约、解约信息异步通知给商户。 官方文档 官方文档

请求头(headers)

Wechatpay-Nonce: 3d980fb850fdce97f6bfb3d248597f16
Wechatpay-Serial: 7132d72a03e93cddf8c03bbd1f37eedf********
Wechatpay-Signature: i48r5y8IQw1qpTO+ywoV...
Wechatpay-Signature-Type: WECHATPAY2-SHA256-RSA2048
Wechatpay-Timestamp: 1710048759
Request-ID: 08F78BB5AF0610D302189F99DD5C20BA56F89845-0

请求报文(body)

{
  "id":"EV-2018022511223320873",
  "create_time":"20180225112233",
  "resource_type":"encrypt-resource",
  "event_type":"ENTRUST.TERMINATE",
  "summary": "签约结果通知",
  "resource" : {
    "algorithm":"AEAD_AES_256_GCM",
    "ciphertext": "...",
    "nonce": "...",
    "associated_data": ""
  }
}

resource.ciphertext 解密后的明文格式

{
  "contract_display_account": "微信代扣用户A",
  "contract_expired_time": "2021-09-10T13:29:35+08:00",
  "contract_id": "123124412412423431",
  "contract_signed_time": "2020-09-10T13:29:35+08:00",
  "contract_state": "TERMINATED",
  "deduct_schedule": {
    "deduct_amount": {
      "currency": "CNY",
      "total": 1
    },
    "deduct_date": "2019-11-22",
    "estimated_deduct_amount": {
      "currency": "CNY",
      "total": 1
    },
    "estimated_deduct_date": "2019-11-22",
    "schedule_state": "PAID",
    "scheduled_amount": {
      "currency": "CNY",
      "total": 1
    }
  },
  "out_contract_code": "wxwtdk20200910100000",
  "out_user_code": "用户A",
  "plan_id": 12535,
  "sp_appid": "wxd678efh567hg6787",
  "sp_mchid": "1900000109",
  "sp_openid": "o-MYE42l80oelYMDE34nYD456Xoy",
  "sub_appid": "wxd678efh567hg6787",
  "sub_mchid": "1900000109",
  "sub_openid": "o-MYE42l80oelYMDE34nYD456Xoy"
}

处理程序

const { Formatter, Rsa, Aes } = require('wechatpay-axios-plugin')

const {
  'wechatpay-nonce': wechatpayNonce,
  'wechatpay-serial': wechatpaySerial,
  'wechatpay-signature': wechatpaySignature,
  'wechatpay-timestamp': wechatpayTimestamp,
} = headers

let code = 'SUCCESS', message = undefined

if (Math.abs(Formatter.timestamp() - wechatpayTimestamp) > MAXIMUM_CLOCK_OFFSET) {
  code = 'FAIL'
  message = 'Over clock offset'
}
else
if (!Object.hasOwn(platformCertificates, wechatpaySerial)) {
  code = 'FAIL'
  message = 'platform certificate not exists'
}
else
if (!Rsa.verify(
  Formatter.joinedByLineFeed(wechatpayTimestamp, wechatpayNonce, json),
  wechatpaySignature,
  platformCertificates[wechatpaySerial]
)) {
  code = 'FAIL'
  message = 'sign mismatched'
}

// do your business
// ...
// ...

const {
  id,
  create_time,
  resource_type,
  event_type,
  resource: {
    ciphertext,
    nonce,
    associated_data
  },
} = JSON.parse(json)

const {
  contract_display_account,
  contract_expired_time,
  contract_id,
  contract_signed_time,
  contract_state,
  deduct_schedule,
  out_contract_code,
  out_user_code,
  plan_id,
  sp_appid,
  sp_mchid,
  sp_openid,
  sub_appid,
  sub_mchid,
  sub_openid,
} = JSON.parse(Aes.AesGcm.decrypt(nonce, apiv3Key, ciphertext, associated_data))

// do your business
// ...
// ...

const response = { code, message }

正常应答头(headers)

Status: 200

正常应答报文(body)

{
  "code": "SUCCESS"
}

注意：

• 同样的通知可能会多次发送给商户系统。商户系统必须能够正确处理重复的通知。 推荐的做法是，当商户系统收到通知进行处理时，先检查对应业务数据的状态，并判断该通知是否已经处理。如果未处理，则再进行处理；如果已处理，则直接返回结果成功。在对业务数据进行状态检查和处理之前，要采用数据锁进行并发控制，以避免函数重入造成的数据混乱。
• 如果在所有通知频率后没有收到微信侧回调，商户应调用查询订单接口确认订单状态。
• 特别提醒：商户系统对于开启结果通知的内容一定要做签名验证，并校验通知的信息是否与商户侧的信息一致，防止数据泄露导致出现“假通知”，造成资金损失。
• 对后台通知交互时，如果微信收到商户的应答不符合规范或超时，微信认为通知失败，微信会通过一定的策略定期重新发起通知，尽可能提高通知的成功率，但微信不保证通知最终能成功。（通知频率为15s/15s/30s/3m/10m/20m/30m/30m/30m/60m/3h/3h/3h/6h/6h - 总计 24h4m）