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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 template_ipsec import TemplateIpsec
class TemplateIPSecNAT(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(TemplateIPSecNAT, cls).setUpClass()
cls.tun_if = cls.pg0
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)
p = cls.ipv4_params
cls.config_esp_tun(p)
cls.logger.info(cls.vapi.ppcli("show ipsec"))
src = socket.inet_pton(p.addr_type, p.remote_tun_if_host)
cls.vapi.ip_add_del_route(src, p.addr_len,
cls.tun_if.remote_addr_n[p.addr_type],
is_ipv6=p.is_ipv6)
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, params):
addr_type = params.addr_type
scapy_tun_sa_id = params.scapy_tun_sa_id
scapy_tun_spi = params.scapy_tun_spi
vpp_tun_sa_id = params.vpp_tun_sa_id
vpp_tun_spi = params.vpp_tun_spi
auth_algo_vpp_id = params.auth_algo_vpp_id
auth_key = params.auth_key
crypt_algo_vpp_id = params.crypt_algo_vpp_id
crypt_key = params.crypt_key
addr_any = params.addr_any
addr_bcast = params.addr_bcast
cls.vapi.ipsec_sad_add_del_entry(scapy_tun_sa_id, scapy_tun_spi,
auth_algo_vpp_id, auth_key,
crypt_algo_vpp_id, crypt_key,
cls.vpp_esp_protocol,
cls.pg1.remote_addr_n[addr_type],
cls.tun_if.remote_addr_n[addr_type],
udp_encap=1)
cls.vapi.ipsec_sad_add_del_entry(vpp_tun_sa_id, vpp_tun_spi,
auth_algo_vpp_id, auth_key,
crypt_algo_vpp_id, crypt_key,
cls.vpp_esp_protocol,
cls.tun_if.remote_addr_n[addr_type],
cls.pg1.remote_addr_n[addr_type],
udp_encap=1)
l_startaddr = r_startaddr = socket.inet_pton(addr_type, addr_any)
l_stopaddr = r_stopaddr = socket.inet_pton(addr_type, addr_bcast)
cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, 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, 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, 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, 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_addr_n[addr_type]
r_startaddr = r_stopaddr = cls.pg1.remote_addr_n[addr_type]
cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, 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, 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 """
p = self.ipv4_params
scapy_tun_sa = SecurityAssociation(ESP, spi=p.scapy_tun_spi,
crypt_algo=p.crypt_algo,
crypt_key=p.crypt_key,
auth_algo=p.auth_algo,
auth_key=p.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=p.vpp_tun_spi,
crypt_algo=p.crypt_algo,
crypt_key=p.crypt_key,
auth_algo=p.auth_algo,
auth_key=p.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)
class IPSecNAT(TemplateIPSecNAT):
""" IPSec/NAT """
pass
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