Generic webhooks

Our generic webhooks integration allows you to subscribe to notifications for certain activity on the Next-Gen WAF.

Adding a webhook

1. Log in to the Next-Gen WAF console.
2. From the Sites menu, select a site if you have more than one site.
3. From the Manage menu, select Site Integrations.
4. Click Add site integration.
5. Select the Generic Webhook integration.
6. In the Webhook URL field, enter a URL to receive the notifications at.
7. Select if you want to be alerted regarding All activity or Specific activity. If you selected Specific activity, in the Activity menu choose the activity types that you want the integration to create alerts for.
8. Click Create site integration.

Notifications format

Notifications are sent with the following format:

1{
2  "created": "2022-12-09T10:43:54-08:00",
3  "type": "flag",
4  "payload": ...,
5  "link":"dashboard link to event"
6}

X-SigSci-Signature Header

All requests sent from the generic webhook integration contain a header called X-SigSci-Signature. The value is an HMAC-SHA256 hex digest hashed using a secret key generated when the generic webhook was created.

The key can be rotated by clicking Edit next to the generic webhook and then Rotate key in the Generic webhook integration form.

Verification is done by creating an HMAC-SHA256 hex digest of the generic webhook payload using the signing key and comparing the result to the value of the X-SigSci-Signature header.

X-SigSci-Signature Header Verification Example Code

The examples show header verification code for X-SigSci-Signature.

Go

1package main
2
3import (
4    "crypto/hmac"
5    "crypto/sha256"
6    "encoding/hex"
7    "fmt"
8)
9
10// CheckMAC reports whether messageMAC is a valid HMAC tag for message.
11func CheckMAC(message, messageMAC, key []byte) bool {
12    mac := hmac.New(sha256.New, key)
13    mac.Write(message)
14    expectedMAC := mac.Sum(nil)
15
16    return hmac.Equal(messageMAC, expectedMAC)
17}
18
19func main() {
20    key := []byte("[insert signing key here]")
21
22    h := "[insert X-SigSci-Signature value here]"
23
24    json := []byte(`[insert JSON payload here]`)
25
26    hash, err := hex.DecodeString(h)
27    if err != nil {
28        log.Fatal("ERROR: ", err)
29    }
30
31    ok := CheckMAC(json, hash, key)
32
33    fmt.Println(ok)
34}

Python

1import hashlib
2import hmac
3
4def checkHMAC(message, messageMAC, key):
5    mac = hmac.new(key, message, digestmod=hashlib.sha256).hexdigest()
6
7    return mac == messageMAC
8
9key = '[insert signing key here]'
10
11h = '[insert X-SigSci-Signature value here]'
12
13json = '[insert JSON payload here]'
14
15ok = checkHMAC(json, h, key)
16
17print(ok)

Ruby

1require 'openssl'
2require "base64"
3
4key = '[insert signing key here]'
5h = '[insert X-SigSci-Signature value here]'
6json = '[insert JSON payload here]'
7
8hash  = OpenSSL::HMAC.hexdigest('sha256', key, json)
9
10puts hash == h

Bash

1#!/bin/bash
2
3function check_hmac {
4  json="$1"
5  messageMAC="$2"
6  key="$3"
7
8  result=$(echo -n "$json" | openssl dgst -sha256 -hmac "$key")
9  if [ "$result" == "$messageMAC" ]
10  then
11          return 0
12  else
13          return 1
14  fi
15}
16
17key='[insert key here]'
18h='[insert X-SigSci-Signature value here]'
19json='[insert JSON payload here]'
20
21check_hmac "$json" $h $key

Activity types