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#!/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 framework import VppTestCase
class IPSecNATTestCase(VppTestCase):
""" IPSec/NAT
TRANSPORT MODE:
--- encrypt ---
|pg2| <-------> |VPP|
--- decrypt ---
TUNNEL MODE:
public network | private network
--- encrypt --- plain ---
|pg0| <------- |VPP| <------ |pg1|
--- --- ---
--- decrypt --- plain ---
|pg0| -------> |VPP| ------> |pg1|
--- --- ---
"""
remote_pg0_client_addr = '1.1.1.1'
@classmethod
def setUpClass(cls):
super(IPSecNATTestCase, cls).setUpClass()
cls.create_pg_interfaces(range(2))
for i in cls.pg_interfaces:
i.configure_ipv4_neighbors()
i.admin_up()
i.config_ip4()
i.resolve_arp()
cls.tcp_port_in = 6303
cls.tcp_port_out = 6303
cls.udp_port_in = 6304
cls.udp_port_out = 6304
cls.icmp_id_in = 6305
cls.icmp_id_out = 6305
cls.config_esp_tun()
cls.logger.info(cls.vapi.ppcli("show ipsec"))
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 check_checksum(self, pkt, layer):
""" Check checksum of the packet on given layer """
new = pkt.__class__(str(pkt))
del new[layer].chksum
new = new.__class__(str(new))
self.assertEqual(new[layer].chksum, pkt[layer].chksum)
def check_ip_checksum(self, pkt):
return self.check_checksum(pkt, 'IP')
def check_tcp_checksum(self, pkt):
return self.check_checksum(pkt, 'TCP')
def check_udp_checksum(self, pkt):
return self.check_checksum(pkt, 'UDP')
def check_icmp_checksum(self, pkt):
return self.check_checksum(pkt, 'ICMP')
def verify_capture_plain(self, capture):
for packet in capture:
try:
self.check_ip_checksum(packet)
self.assert_equal(packet[IP].src, self.pg0.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")
self.check_tcp_checksum(packet)
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")
self.check_icmp_checksum(packet)
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:
self.assertIn(ESP, packet[IP])
decrypt_pkt = sa.decrypt(packet[IP])
self.assert_equal(decrypt_pkt[IP].src, self.pg1.remote_ip4,
"encrypted packet source address")
self.assert_equal(decrypt_pkt[IP].dst, self.pg0.remote_ip4,
"encrypted packet destination address")
# if decrypt_pkt.haslayer(TCP):
# self.tcp_port_out = decrypt_pkt[TCP].sport
# elif decrypt_pkt.haslayer(UDP):
# self.udp_port_out = decrypt_pkt[UDP].sport
# else:
# self.icmp_id_out = decrypt_pkt[ICMP].id
except Exception:
self.logger.error(
ppp("Unexpected or invalid encrypted packet:", packet))
raise
@classmethod
def config_esp_tun(cls):
spd_id = 1
remote_sa_id = 10
local_sa_id = 20
remote_tun_spi = 1001
local_tun_spi = 1000
client = socket.inet_pton(socket.AF_INET, cls.remote_pg0_client_addr)
cls.vapi.ip_add_del_route(client, 32, cls.pg0.remote_ip4n)
cls.vapi.ipsec_sad_add_del_entry(remote_sa_id, remote_tun_spi,
cls.pg1.remote_ip4n,
cls.pg0.remote_ip4n,
integrity_key_length=20,
crypto_key_length=16,
protocol=1, udp_encap=1)
cls.vapi.ipsec_sad_add_del_entry(local_sa_id, local_tun_spi,
cls.pg0.remote_ip4n,
cls.pg1.remote_ip4n,
integrity_key_length=20,
crypto_key_length=16,
protocol=1, udp_encap=1)
cls.vapi.ipsec_spd_add_del(spd_id)
cls.vapi.ipsec_interface_add_del_spd(spd_id, cls.pg0.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(spd_id, l_startaddr, l_stopaddr,
r_startaddr, r_stopaddr,
protocol=socket.IPPROTO_ESP)
cls.vapi.ipsec_spd_add_del_entry(spd_id, l_startaddr, l_stopaddr,
r_startaddr, r_stopaddr,
protocol=socket.IPPROTO_ESP,
is_outbound=0)
cls.vapi.ipsec_spd_add_del_entry(spd_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(spd_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.pg0.remote_ip4n
r_startaddr = r_stopaddr = cls.pg1.remote_ip4n
cls.vapi.ipsec_spd_add_del_entry(spd_id, l_startaddr, l_stopaddr,
r_startaddr, r_stopaddr,
priority=10, policy=3,
is_outbound=0, sa_id=local_sa_id)
cls.vapi.ipsec_spd_add_del_entry(spd_id, r_startaddr, r_stopaddr,
l_startaddr, l_stopaddr,
priority=10, policy=3,
sa_id=remote_sa_id)
def test_ipsec_nat_tun(self):
""" IPSec/NAT tunnel test case """
local_tun_sa = SecurityAssociation(ESP, spi=0x000003e9,
crypt_algo='AES-CBC',
crypt_key='JPjyOWBeVEQiMe7h',
auth_algo='HMAC-SHA1-96',
auth_key='C91KUR9GYMm5GfkEvNjX',
tunnel_header=IP(
src=self.pg1.remote_ip4,
dst=self.pg0.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.pg0.remote_ip4)
self.pg1.add_stream(pkts)
self.pg_enable_capture(self.pg_interfaces)
self.pg_start()
capture = self.pg0.get_capture(len(pkts))
self.verify_capture_encrypted(capture, local_tun_sa)
remote_tun_sa = SecurityAssociation(ESP, spi=0x000003e8,
crypt_algo='AES-CBC',
crypt_key='JPjyOWBeVEQiMe7h',
auth_algo='HMAC-SHA1-96',
auth_key='C91KUR9GYMm5GfkEvNjX',
tunnel_header=IP(
src=self.pg0.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.pg0.remote_mac, self.pg0.local_mac,
self.pg0.remote_ip4, self.pg1.remote_ip4, remote_tun_sa)
self.logger.info(ppc("Sending packets:", pkts))
self.pg0.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)
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