Python

def do_lagom_verif(self, path, amount):
	# extract params from url, decode and parse
	parsed = urlparse.urlparse(self.path)
	params = urlparse.parse_qs(parsed.query)
	uid = params['lguid'][0] if 'lguid' in params else ''
	ts = params['lgts'][0]
	sig = params['lgsig'][0]
	id = params['lgid'][0]
	amt = params['lgamt'][0]

	# check timestamp is within 10 seconds
	current_time = int(time.time())
	if current_time > int(ts) + 5:
		return False

	# check amount and path
	if int(amt) != amount or path != parsed.path:
		return False

	# check signature - we also verify that the payment only applies to this page
	verif = uid.encode('utf-8') + id.encode('utf-8') + ts.encode('utf-8') + parsed.path.encode('utf-8') + amt.encode('utf-8')
	good = hmac.new(SECRET.encode('utf-8'), verif, hashlib.sha256).hexdigest()
	if sig != good:
		return False

	return True