validate_signature.py

# Validate the signature
def validate_signature(GITHUB_SECRET, event, body):
  
  incoming_signature = re.sub(r'^sha1=', '', event['headers']['X-Hub-Signature'])
  incoming_payload = unquote(re.sub(r'^payload=', '', event['body']))
  calculated_signature = calculate_signature(GITHUB_SECRET, incoming_payload.encode('utf-8'))

  if incoming_signature != calculated_signature:
    print("Unauthorized attempt")
    sys.exit()
  else:
    print("🚀 Confirmed HMAC matches, authorized access, continuing")