Closes #3952: Add test for webhooks_worker; introduce generate_signature()

Author: jeremystretch

netbox/extras/tests/test_webhooks.py

@@ -1,11 +1,19 @@
+import json
+import uuid
+from unittest.mock import patch
+
 import django_rq
 from django.contrib.contenttypes.models import ContentType
+from django.http import HttpResponse
 from django.urls import reverse
+from requests import Session
 from rest_framework import status
 
 from dcim.models import Site
 from extras.choices import ObjectChangeActionChoices
 from extras.models import Webhook
+from extras.webhooks import enqueue_webhooks, generate_signature
+from extras.webhooks_worker import process_webhook
 from utilities.testing import APITestCase
 
 
@@ -22,11 +30,13 @@ def setUp(self):
     def setUpTestData(cls):
 
         site_ct = ContentType.objects.get_for_model(Site)
-        PAYLOAD_URL = "http://localhost/"
+        DUMMY_URL = "http://localhost/"
+        DUMMY_SECRET = "LOOKATMEIMASECRETSTRING"
+
         webhooks = Webhook.objects.bulk_create((
-            Webhook(name='Site Create Webhook', type_create=True, payload_url=PAYLOAD_URL),
-            Webhook(name='Site Update Webhook', type_update=True, payload_url=PAYLOAD_URL),
-            Webhook(name='Site Delete Webhook', type_delete=True, payload_url=PAYLOAD_URL),
+            Webhook(name='Site Create Webhook', type_create=True, payload_url=DUMMY_URL, secret=DUMMY_SECRET, additional_headers={'X-Foo': 'Bar'}),
+            Webhook(name='Site Update Webhook', type_update=True, payload_url=DUMMY_URL, secret=DUMMY_SECRET),
+            Webhook(name='Site Delete Webhook', type_delete=True, payload_url=DUMMY_URL, secret=DUMMY_SECRET),
         ))
         for webhook in webhooks:
             webhook.obj_type.set([site_ct])
@@ -87,3 +97,47 @@ def test_enqueue_webhook_delete(self):
         self.assertEqual(job.args[1]['id'], site.pk)
         self.assertEqual(job.args[2], 'site')
         self.assertEqual(job.args[3], ObjectChangeActionChoices.ACTION_DELETE)
+
+    def test_webhooks_worker(self):
+
+        request_id = uuid.uuid4()
+
+        def dummy_send(_, request):
+            """
+            A dummy implementation of Session.send() to be used for testing.
+            Always returns a 200 HTTP response.
+            """
+            webhook = Webhook.objects.get(type_create=True)
+            signature = generate_signature(request.body, webhook.secret)
+
+            # Validate the outgoing request headers
+            self.assertEqual(request.headers['Content-Type'], webhook.http_content_type)
+            self.assertEqual(request.headers['X-Hook-Signature'], signature)
+            self.assertEqual(request.headers['X-Foo'], 'Bar')
+
+            # Validate the outgoing request body
+            body = json.loads(request.body)
+            self.assertEqual(body['event'], 'created')
+            self.assertEqual(body['timestamp'], job.args[4])
+            self.assertEqual(body['model'], 'site')
+            self.assertEqual(body['username'], 'testuser')
+            self.assertEqual(body['request_id'], str(request_id))
+            self.assertEqual(body['data']['name'], 'Site 1')
+
+            return HttpResponse()
+
+        # Enqueue a webhook for processing
+        site = Site.objects.create(name='Site 1', slug='site-1')
+        enqueue_webhooks(
+            instance=site,
+            user=self.user,
+            request_id=request_id,
+            action=ObjectChangeActionChoices.ACTION_CREATE
+        )
+
+        # Retrieve the job from queue
+        job = self.queue.jobs[0]
+
+        # Patch the Session object with our dummy_send() method, then process the webhook for sending
+        with patch.object(Session, 'send', dummy_send) as mock_send:
+            process_webhook(*job.args)

netbox/extras/webhooks.py

@@ -1,4 +1,6 @@
 import datetime
+import hashlib
+import hmac
 
 from django.contrib.contenttypes.models import ContentType
 
@@ -8,6 +10,18 @@
 from .constants import *
 
 
+def generate_signature(request_body, secret):
+    """
+    Return a cryptographic signature that can be used to verify the authenticity of webhook data.
+    """
+    hmac_prep = hmac.new(
+        key=secret.encode('utf8'),
+        msg=request_body.encode('utf8'),
+        digestmod=hashlib.sha512
+    )
+    return hmac_prep.hexdigest()
+
+
 def enqueue_webhooks(instance, user, request_id, action):
     """
     Find Webhook(s) assigned to this instance + action and enqueue them

netbox/extras/webhooks_worker.py

@@ -1,12 +1,11 @@
-import hashlib
-import hmac
 import json
 
 import requests
 from django_rq import job
 from rest_framework.utils.encoders import JSONEncoder
 
 from .choices import ObjectChangeActionChoices, WebhookContentTypeChoices
+from .webhooks import generate_signature
 
 
 @job('default')
@@ -43,20 +42,15 @@ def process_webhook(webhook, data, model_name, event, timestamp, username, reque
 
     if webhook.secret != '':
         # Sign the request with a hash of the secret key and its content.
-        hmac_prep = hmac.new(
-            key=webhook.secret.encode('utf8'),
-            msg=prepared_request.body.encode('utf8'),
-            digestmod=hashlib.sha512
-        )
-        prepared_request.headers['X-Hook-Signature'] = hmac_prep.hexdigest()
+        prepared_request.headers['X-Hook-Signature'] = generate_signature(prepared_request.body, webhook.secret)
 
     with requests.Session() as session:
         session.verify = webhook.ssl_verification
         if webhook.ca_file_path:
             session.verify = webhook.ca_file_path
         response = session.send(prepared_request)
 
-    if response.status_code >= 200 and response.status_code <= 299:
+    if 200 <= response.status_code <= 299:
         return 'Status {} returned, webhook successfully processed.'.format(response.status_code)
     else:
         raise requests.exceptions.RequestException(