#!/usr/bin/env python import socket from scapy.layers.l2 import Ether from scapy.layers.inet import ICMP, IP, TCP, UDP from scapy.layers.ipsec import SecurityAssociation, ESP from util import ppp, ppc from template_ipsec import TemplateIpsec class IPSecNATTestCase(TemplateIpsec): """ IPSec/NAT TUNNEL MODE: public network | private network --- encrypt --- plain --- |pg0| <------- |VPP| <------ |pg1| --- --- --- --- decrypt --- plain --- |pg0| -------> |VPP| ------> |pg1| --- --- --- """ tcp_port_in = 6303 tcp_port_out = 6303 udp_port_in = 6304 udp_port_out = 6304 icmp_id_in = 6305 icmp_id_out = 6305 @classmethod def setUpClass(cls): super(IPSecNATTestCase, cls).setUpClass() cls.tun_if = cls.pg0 cls.config_esp_tun() cls.logger.info(cls.vapi.ppcli("show ipsec")) client = socket.inet_pton(socket.AF_INET, cls.remote_tun_if_host) cls.vapi.ip_add_del_route(client, 32, cls.tun_if.remote_ip4n) def create_stream_plain(self, src_mac, dst_mac, src_ip, dst_ip): return [ # TCP Ether(src=src_mac, dst=dst_mac) / IP(src=src_ip, dst=dst_ip) / TCP(sport=self.tcp_port_in, dport=20), # UDP Ether(src=src_mac, dst=dst_mac) / IP(src=src_ip, dst=dst_ip) / UDP(sport=self.udp_port_in, dport=20), # ICMP Ether(src=src_mac, dst=dst_mac) / IP(src=src_ip, dst=dst_ip) / ICMP(id=self.icmp_id_in, type='echo-request') ] def create_stream_encrypted(self, src_mac, dst_mac, src_ip, dst_ip, sa): return [ # TCP Ether(src=src_mac, dst=dst_mac) / sa.encrypt(IP(src=src_ip, dst=dst_ip) / TCP(dport=self.tcp_port_out, sport=20)), # UDP Ether(src=src_mac, dst=dst_mac) / sa.encrypt(IP(src=src_ip, dst=dst_ip) / UDP(dport=self.udp_port_out, sport=20)), # ICMP Ether(src=src_mac, dst=dst_mac) / sa.encrypt(IP(src=src_ip, dst=dst_ip) / ICMP(id=self.icmp_id_out, type='echo-request')) ] def verify_capture_plain(self, capture): for packet in capture: try: self.assert_packet_checksums_valid(packet) self.assert_equal(packet[IP].src, self.tun_if.remote_ip4, "decrypted packet source address") self.assert_equal(packet[IP].dst, self.pg1.remote_ip4, "decrypted packet destination address") if packet.haslayer(TCP): self.assertFalse( packet.haslayer(UDP), "unexpected UDP header in decrypted packet") self.assert_equal(packet[TCP].dport, self.tcp_port_in, "decrypted packet TCP destination port") elif packet.haslayer(UDP): if packet[UDP].payload: self.assertFalse( packet[UDP][1].haslayer(UDP), "unexpected UDP header in decrypted packet") self.assert_equal(packet[UDP].dport, self.udp_port_in, "decrypted packet UDP destination port") else: self.assertFalse( packet.haslayer(UDP), "unexpected UDP header in decrypted packet") self.assert_equal(packet[ICMP].id, self.icmp_id_in, "decrypted packet ICMP ID") except Exception: self.logger.error( ppp("Unexpected or invalid plain packet:", packet)) raise def verify_capture_encrypted(self, capture, sa): for packet in capture: try: copy = packet.__class__(str(packet)) del copy[UDP].len copy = packet.__class__(str(copy)) self.assert_equal(packet[UDP].len, copy[UDP].len, "UDP header length") self.assert_packet_checksums_valid(packet) self.assertIn(ESP, packet[IP]) decrypt_pkt = sa.decrypt(packet[IP]) self.assert_packet_checksums_valid(decrypt_pkt) self.assert_equal(decrypt_pkt[IP].src, self.pg1.remote_ip4, "encrypted packet source address") self.assert_equal(decrypt_pkt[IP].dst, self.tun_if.remote_ip4, "encrypted packet destination address") except Exception: self.logger.error( ppp("Unexpected or invalid encrypted packet:", packet)) raise @classmethod def config_esp_tun(cls): cls.vapi.ipsec_sad_add_del_entry(cls.scapy_tun_sa_id, cls.scapy_tun_spi, cls.auth_algo_vpp_id, cls.auth_key, cls.crypt_algo_vpp_id, cls.crypt_key, cls.vpp_esp_protocol, cls.pg1.remote_ip4n, cls.tun_if.remote_ip4n, udp_encap=1) cls.vapi.ipsec_sad_add_del_entry(cls.vpp_tun_sa_id, cls.vpp_tun_spi, cls.auth_algo_vpp_id, cls.auth_key, cls.crypt_algo_vpp_id, cls.crypt_key, cls.vpp_esp_protocol, cls.tun_if.remote_ip4n, cls.pg1.remote_ip4n, udp_encap=1) cls.vapi.ipsec_spd_add_del(cls.tun_spd_id) cls.vapi.ipsec_interface_add_del_spd(cls.tun_spd_id, cls.tun_if.sw_if_index) l_startaddr = r_startaddr = socket.inet_pton(socket.AF_INET, "0.0.0.0") l_stopaddr = r_stopaddr = socket.inet_pton(socket.AF_INET, "255.255.255.255") cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.scapy_tun_sa_id, l_startaddr, l_stopaddr, r_startaddr, r_stopaddr, protocol=socket.IPPROTO_ESP) cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.scapy_tun_sa_id, l_startaddr, l_stopaddr, r_startaddr, r_stopaddr, is_outbound=0, protocol=socket.IPPROTO_ESP) cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.scapy_tun_sa_id, l_startaddr, l_stopaddr, r_startaddr, r_stopaddr, remote_port_start=4500, remote_port_stop=4500, protocol=socket.IPPROTO_UDP) cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.scapy_tun_sa_id, l_startaddr, l_stopaddr, r_startaddr, r_stopaddr, remote_port_start=4500, remote_port_stop=4500, protocol=socket.IPPROTO_UDP, is_outbound=0) l_startaddr = l_stopaddr = cls.tun_if.remote_ip4n r_startaddr = r_stopaddr = cls.pg1.remote_ip4n cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.vpp_tun_sa_id, l_startaddr, l_stopaddr, r_startaddr, r_stopaddr, priority=10, policy=3, is_outbound=0) cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, cls.scapy_tun_sa_id, r_startaddr, r_stopaddr, l_startaddr, l_stopaddr, priority=10, policy=3) def test_ipsec_nat_tun(self): """ IPSec/NAT tunnel test case """ scapy_tun_sa = SecurityAssociation(ESP, spi=self.scapy_tun_spi, crypt_algo=self.crypt_algo, crypt_key=self.crypt_key, auth_algo=self.auth_algo, auth_key=self.auth_key, tunnel_header=IP( src=self.pg1.remote_ip4, dst=self.tun_if.remote_ip4), nat_t_header=UDP( sport=4500, dport=4500)) # in2out - from private network to public pkts = self.create_stream_plain( self.pg1.remote_mac, self.pg1.local_mac, self.pg1.remote_ip4, self.tun_if.remote_ip4) self.pg1.add_stream(pkts) self.pg_enable_capture(self.pg_interfaces) self.pg_start() capture = self.tun_if.get_capture(len(pkts)) self.verify_capture_encrypted(capture, scapy_tun_sa) vpp_tun_sa = SecurityAssociation(ESP, spi=self.vpp_tun_spi, crypt_algo=self.crypt_algo, crypt_key=self.crypt_key, auth_algo=self.auth_algo, auth_key=self.auth_key, tunnel_header=IP( src=self.tun_if.remote_ip4, dst=self.pg1.remote_ip4), nat_t_header=UDP( sport=4500, dport=4500)) # out2in - from public network to private pkts = self.create_stream_encrypted( self.tun_if.remote_mac, self.tun_if.local_mac, self.tun_if.remote_ip4, self.pg1.remote_ip4, vpp_tun_sa) self.logger.info(ppc("Sending packets:", pkts)) self.tun_if.add_stream(pkts) self.pg_enable_capture(self.pg_interfaces) self.pg_start() capture = self.pg1.get_capture(len(pkts)) self.verify_capture_plain(capture)