Skip to content

Instantly share code, notes, and snippets.

Last active November 5, 2020 15:10
Show Gist options
  • Save andrewgross/8ba32af80ecccb894b82774782e7dcd4 to your computer and use it in GitHub Desktop.
Save andrewgross/8ba32af80ecccb894b82774782e7dcd4 to your computer and use it in GitHub Desktop.
Django View to check travis CI webhook signatures. Requires Django, python-requests and pyOpenSSL packages
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
import base64
import json
import logging
from urlparse import parse_qs
import requests
from OpenSSL.crypto import verify, load_publickey, FILETYPE_PEM, X509
from OpenSSL.crypto import Error as SignatureError
from django.conf import settings
from django.views.generic import View
from django.http import HttpResponseBadRequest, JsonResponse
logger = logging.getLogger(__name__)
class Travis(View):
# Make sure you use the correct config URL, the .org and .com
# have different keys!
def post(self, request, *args, **kwargs):
signature = self._get_signature(request)
json_payload = parse_qs(request.body)['payload'][0]
public_key = self._get_travis_public_key()
except requests.Timeout:
logger.error({"message": "Timed out when attempting to retrieve Travis CI public key"})
return HttpResponseBadRequest({'status': 'failed'})
except requests.RequestException as e:
logger.error({"message": "Failed to retrieve Travis CI public key", 'error': e.message})
return HttpResponseBadRequest({'status': 'failed'})
self.check_authorized(signature, public_key, json_payload)
except SignatureError:
# Log the failure somewhere
return HttpResponseBadRequest({'status': 'unauthorized'})
json_data = json.loads(json_payload)
return JsonResponse({'status': 'received'})
def check_authorized(self, signature, public_key, payload):
Convert the PEM encoded public key to a format palatable for pyOpenSSL,
then verify the signature
pkey_public_key = load_publickey(FILETYPE_PEM, public_key)
certificate = X509()
verify(certificate, signature, payload, str('sha1'))
def _get_signature(self, request):
Extract the raw bytes of the request signature provided by travis
signature = request.META['HTTP_SIGNATURE']
return base64.b64decode(signature)
def _get_travis_public_key(self):
Returns the PEM encoded public key from the Travis CI /config endpoint
response = requests.get(self.TRAVIS_CONFIG_URL, timeout=10.0)
return response.json()['config']['notifications']['webhook']['public_key']
Copy link

andrewgross commented Sep 14, 2016

Fixed the body loading logic again, as the Sinatra example has a bug (I think). Also added note that you MUST use the correct .com or .org config endpoint, depending where the hook comes from.

EDIT: Their example is correct, I did not realize Sinatra auto unpacks based on the Content Type header.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment