const Koa = require('koa')

const sha1 = require('sha1')

const app = new Koa()

const config = {

  wechat: {

    appID: '', //填写你自己的appID

    appSecret: '',  //填写你自己的appSecret

    token: ''  //填写你自己的token

  }

}

app.use(async (ctx) => {

  const token = config.wechat.token

  const signature = ctx.request.query.signature

  const nonce = ctx.request.query.nonce

  const timestamp = ctx.request.query.timestamp

  const echostr = ctx.request.query.echostr

  let str = [token, timestamp, nonce].sort().join('')

  const sha = sha1(str)

  ctx.body = sha === signature ? echostr + '' : 'failed'

})

app.listen(, () => {

  console.log('node started port 8999')

})