How can i confirm the subscription request HTTP from amazon SNS

Question

I have been searching all over the web and nothing gives a clear answer to confirm the subscription request from amazon SNS. I already send the subscription from the amazon

Answer 1

Here is an express application (Node.js) which confirms the SNS subscription:

const express = require('express')
const request = require('request')
// parse urlencoded request bodies into req.body
const bodyParser = require('body-parser')
const app = express()
const port = 8080

app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())

app.post('/', (req, res) => {
  let body = ''

  req.on('data', (chunk) => {
    body += chunk.toString()
  })

  req.on('end', () => {
    let payload = JSON.parse(body)

    if (payload.Type === 'SubscriptionConfirmation') {
      const promise = new Promise((resolve, reject) => {
        const url = payload.SubscribeURL

        request(url, (error, response) => {
          if (!error && response.statusCode == 200) {
            console.log('Yess! We have accepted the confirmation from AWS')
            return resolve()
          } else {
            return reject()
          }
        })
      })

      promise.then(() => {
        res.end("ok")
      })
    }
  })
})

app.listen(port, () => console.log('Example app listening on port ' + port + '!'))

To use it one needs to install required packages:

yarn add express request body-parser

Once you confirm the subscription AWS will send a POST request to the server with the following content:

{
  "Type": "SubscriptionConfirmation",
  "MessageId": "XXXXXXXX-1ee3-4de3-9c69-XXXXXXXXXXXX",
  "Token": "SECRET_TOKEN",
  "TopicArn": "arn:aws:sns:us-west-2:XXXXXXXXXXXX:ses-test",
  "Message": "You have chosen to subscribe to the topic arn:aws:sns:us-west-2:XXXXXXXXXXXX:ses-test. To confirm the subscription, visit the SubscribeURL included in this message.",
  "SubscribeURL": "https://sns.us-west-2.amazonaws.com/?Action=ConfirmSubscription&TopicArn=arn:aws:sns:us-west-2:XXXXXXXXXXXX:ses-test&Token=SECRET_TOKEN",
  "Timestamp": "2018-11-21T19:48:08.170Z",
  "SignatureVersion": "1",
  "Signature": "SECRET",
  "SigningCertURL": "https://sns.us-west-2.amazonaws.com/SimpleNotificationService-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.pem"
}

The payload contains SubscribeURL which is requested by the server.