+ @staticmethod
+ def find_notify_payload(packet, notify_type):
+ n = packet[ikev2.IKEv2_payload_Notify]
+ while n is not None:
+ if n.type == notify_type:
+ return n
+ n = n.payload
+ return None
+
+ def verify_nat_detection(self, packet):
+ if self.ip6:
+ iph = packet[IPv6]
+ else:
+ iph = packet[IP]
+ udp = packet[UDP]
+
+ # NAT_DETECTION_SOURCE_IP
+ s = self.find_notify_payload(packet, 16388)
+ self.assertIsNotNone(s)
+ src_sha = self.sa.compute_nat_sha1(
+ inet_pton(socket.AF_INET, iph.src), udp.sport, b'\x00' * 8)
+ self.assertEqual(s.load, src_sha)
+
+ # NAT_DETECTION_DESTINATION_IP
+ s = self.find_notify_payload(packet, 16389)
+ self.assertIsNotNone(s)
+ dst_sha = self.sa.compute_nat_sha1(
+ inet_pton(socket.AF_INET, iph.dst), udp.dport, b'\x00' * 8)
+ self.assertEqual(s.load, dst_sha)
+