代扣解约挽留业务-获取解约挽留信息(JSON)

当用户关闭协议时，协议所关联的模板在获取范围内，则主动的获取挽留信息。 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_RETENTION",
  "summary": "获取解约挽留信息",
  "resource" : {
    "original_type":"entrust",
    "algorithm":"AEAD_AES_256_GCM",
    "ciphertext": "...",
    "nonce": "...",
    "associated_data": ""
  }
}

resource.ciphertext 解密后的明文格式

{
  "appid": "wxd678efh567hg6787",
  "contract_id": "123124412412423431",
  "mchid": "1900000109",
  "openid": "o-MYE42l80oelYMDE34nYD456Xoy",
  "out_contract_code": "wxwtdk20200910100000",
  "plan_id": 12535
}

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 {
  appid,
  contract_id,
  mchid,
  openid,
  out_contract_code,
  plan_id,
} = JSON.parse(Aes.AesGcm.decrypt(nonce, apiv3Key, ciphertext, associated_data))

// do your business
// ...
// ...
const response = { code, message, retention_type, coupon_info: { state, coupon_id } }

正常应答头(headers)

Status: 200

正常应答报文(body)

{
  "code": "SUCCESS",
  "message": "",
  "retention_type": "COUPON",
  "coupon_info": {
    "state": "SEND_COUPON",
    "coupon_id": "9867041"
  }
}

注意：

• 对后台交互时，如果微信收到应答不是成功或超时（当前是1秒的超时），微信认为获取失败，不会展示挽留信息。
• 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。