Fix TimestampVerifier delta check (#118)

Author: timothyaaron

ask-sdk-webservice-support/ask_sdk_webservice_support/verifier.py

@@ -432,6 +432,6 @@ def verify(
         """
         local_now = datetime.now(tz.tzutc())
         request_timestamp = deserialized_request_env.request.timestamp
-        if (abs((local_now - request_timestamp).seconds) >
+        if (abs((local_now - request_timestamp).total_seconds()) >
                 (self._tolerance_in_millis / 1000)):
             raise VerificationException("Timestamp verification failed")

ask-sdk-webservice-support/tests/unit/test_verifier.py

@@ -396,6 +396,23 @@ def test_timestamp_verification_with_expired_timestamp(self):
 
         self.assertIn("Timestamp verification failed", str(exc.exception))
 
+    def test_timestamp_verification_with_valid_future_server_timestamp(self):
+        valid_tolerance = int(DEFAULT_TIMESTAMP_TOLERANCE_IN_MILLIS / 2 / 1000)
+        valid_future_datetime = datetime.now(tzutc()) + timedelta(seconds=valid_tolerance)
+        test_request_envelope = RequestEnvelope(
+            request=IntentRequest(
+                timestamp=valid_future_datetime))
+        self.timestamp_verifier = TimestampVerifier()
+        try:
+            self.timestamp_verifier.verify(
+                headers={},
+                serialized_request_env="",
+                deserialized_request_env=test_request_envelope)
+        except:
+            # Should never reach here
+            raise self.fail(
+                "Timestamp verification failed for a valid input request")
+
     def test_timestamp_verification_with_valid_timestamp(self):
         test_request_envelope = RequestEnvelope(
             request=IntentRequest(