test/test_ipsec_nat.py

   1 #!/usr/bin/env python
   2
   3 import socket
   4
   5 from scapy.layers.l2 import Ether
   6 from scapy.layers.inet import ICMP, IP, TCP, UDP
   7 from scapy.layers.ipsec import SecurityAssociation, ESP
   8 from util import ppp, ppc
   9 from template_ipsec import TemplateIpsec
  10
  11
  12 class IPSecNATTestCase(TemplateIpsec):
  13     """ IPSec/NAT
  14     TUNNEL MODE:
  15
  16
  17      public network  |   private network
  18      ---   encrypt  ---   plain   ---
  19     |pg0| <------- |VPP| <------ |pg1|
  20      ---            ---           ---
  21
  22      ---   decrypt  ---   plain   ---
  23     |pg0| -------> |VPP| ------> |pg1|
  24      ---            ---           ---
  25     """
  26
  27     tcp_port_in = 6303
  28     tcp_port_out = 6303
  29     udp_port_in = 6304
  30     udp_port_out = 6304
  31     icmp_id_in = 6305
  32     icmp_id_out = 6305
  33
  34     @classmethod
  35     def setUpClass(cls):
  36         super(IPSecNATTestCase, cls).setUpClass()
  37         cls.tun_if = cls.pg0
  38         cls.vapi.ipsec_spd_add_del(cls.tun_spd_id)
  39         cls.vapi.ipsec_interface_add_del_spd(cls.tun_spd_id,
  40                                              cls.tun_if.sw_if_index)
  41         p = cls.ipv4_params
  42         cls.config_esp_tun(p)
  43         cls.logger.info(cls.vapi.ppcli("show ipsec"))
  44         src = socket.inet_pton(p.addr_type, p.remote_tun_if_host)
  45         cls.vapi.ip_add_del_route(src, p.addr_len,
  46                                   cls.tun_if.remote_addr_n[p.addr_type],
  47                                   is_ipv6=p.is_ipv6)
  48
  49     def create_stream_plain(self, src_mac, dst_mac, src_ip, dst_ip):
  50         return [
  51             # TCP
  52             Ether(src=src_mac, dst=dst_mac) /
  53             IP(src=src_ip, dst=dst_ip) /
  54             TCP(sport=self.tcp_port_in, dport=20),
  55             # UDP
  56             Ether(src=src_mac, dst=dst_mac) /
  57             IP(src=src_ip, dst=dst_ip) /
  58             UDP(sport=self.udp_port_in, dport=20),
  59             # ICMP
  60             Ether(src=src_mac, dst=dst_mac) /
  61             IP(src=src_ip, dst=dst_ip) /
  62             ICMP(id=self.icmp_id_in, type='echo-request')
  63         ]
  64
  65     def create_stream_encrypted(self, src_mac, dst_mac, src_ip, dst_ip, sa):
  66         return [
  67             # TCP
  68             Ether(src=src_mac, dst=dst_mac) /
  69             sa.encrypt(IP(src=src_ip, dst=dst_ip) /
  70                        TCP(dport=self.tcp_port_out, sport=20)),
  71             # UDP
  72             Ether(src=src_mac, dst=dst_mac) /
  73             sa.encrypt(IP(src=src_ip, dst=dst_ip) /
  74                        UDP(dport=self.udp_port_out, sport=20)),
  75             # ICMP
  76             Ether(src=src_mac, dst=dst_mac) /
  77             sa.encrypt(IP(src=src_ip, dst=dst_ip) /
  78                        ICMP(id=self.icmp_id_out, type='echo-request'))
  79         ]
  80
  81     def verify_capture_plain(self, capture):
  82         for packet in capture:
  83             try:
  84                 self.assert_packet_checksums_valid(packet)
  85                 self.assert_equal(packet[IP].src, self.tun_if.remote_ip4,
  86                                   "decrypted packet source address")
  87                 self.assert_equal(packet[IP].dst, self.pg1.remote_ip4,
  88                                   "decrypted packet destination address")
  89                 if packet.haslayer(TCP):
  90                     self.assertFalse(
  91                         packet.haslayer(UDP),
  92                         "unexpected UDP header in decrypted packet")
  93                     self.assert_equal(packet[TCP].dport, self.tcp_port_in,
  94                                       "decrypted packet TCP destination port")
  95                 elif packet.haslayer(UDP):
  96                     if packet[UDP].payload:
  97                         self.assertFalse(
  98                             packet[UDP][1].haslayer(UDP),
  99                             "unexpected UDP header in decrypted packet")
 100                     self.assert_equal(packet[UDP].dport, self.udp_port_in,
 101                                       "decrypted packet UDP destination port")
 102                 else:
 103                     self.assertFalse(
 104                         packet.haslayer(UDP),
 105                         "unexpected UDP header in decrypted packet")
 106                     self.assert_equal(packet[ICMP].id, self.icmp_id_in,
 107                                       "decrypted packet ICMP ID")
 108             except Exception:
 109                 self.logger.error(
 110                     ppp("Unexpected or invalid plain packet:", packet))
 111                 raise
 112
 113     def verify_capture_encrypted(self, capture, sa):
 114         for packet in capture:
 115             try:
 116                 copy = packet.__class__(str(packet))
 117                 del copy[UDP].len
 118                 copy = packet.__class__(str(copy))
 119                 self.assert_equal(packet[UDP].len, copy[UDP].len,
 120                                   "UDP header length")
 121                 self.assert_packet_checksums_valid(packet)
 122                 self.assertIn(ESP, packet[IP])
 123                 decrypt_pkt = sa.decrypt(packet[IP])
 124                 self.assert_packet_checksums_valid(decrypt_pkt)
 125                 self.assert_equal(decrypt_pkt[IP].src, self.pg1.remote_ip4,
 126                                   "encrypted packet source address")
 127                 self.assert_equal(decrypt_pkt[IP].dst, self.tun_if.remote_ip4,
 128                                   "encrypted packet destination address")
 129             except Exception:
 130                 self.logger.error(
 131                     ppp("Unexpected or invalid encrypted packet:", packet))
 132                 raise
 133
 134     @classmethod
 135     def config_esp_tun(cls, params):
 136         addr_type = params.addr_type
 137         scapy_tun_sa_id = params.scapy_tun_sa_id
 138         scapy_tun_spi = params.scapy_tun_spi
 139         vpp_tun_sa_id = params.vpp_tun_sa_id
 140         vpp_tun_spi = params.vpp_tun_spi
 141         auth_algo_vpp_id = params.auth_algo_vpp_id
 142         auth_key = params.auth_key
 143         crypt_algo_vpp_id = params.crypt_algo_vpp_id
 144         crypt_key = params.crypt_key
 145         addr_any = params.addr_any
 146         addr_bcast = params.addr_bcast
 147         cls.vapi.ipsec_sad_add_del_entry(scapy_tun_sa_id, scapy_tun_spi,
 148                                          auth_algo_vpp_id, auth_key,
 149                                          crypt_algo_vpp_id, crypt_key,
 150                                          cls.vpp_esp_protocol,
 151                                          cls.pg1.remote_addr_n[addr_type],
 152                                          cls.tun_if.remote_addr_n[addr_type],
 153                                          udp_encap=1)
 154         cls.vapi.ipsec_sad_add_del_entry(vpp_tun_sa_id, vpp_tun_spi,
 155                                          auth_algo_vpp_id, auth_key,
 156                                          crypt_algo_vpp_id, crypt_key,
 157                                          cls.vpp_esp_protocol,
 158                                          cls.tun_if.remote_addr_n[addr_type],
 159                                          cls.pg1.remote_addr_n[addr_type],
 160                                          udp_encap=1)
 161         l_startaddr = r_startaddr = socket.inet_pton(addr_type, addr_any)
 162         l_stopaddr = r_stopaddr = socket.inet_pton(addr_type, addr_bcast)
 163         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, scapy_tun_sa_id,
 164                                          l_startaddr, l_stopaddr, r_startaddr,
 165                                          r_stopaddr,
 166                                          protocol=socket.IPPROTO_ESP)
 167         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, scapy_tun_sa_id,
 168                                          l_startaddr, l_stopaddr, r_startaddr,
 169                                          r_stopaddr, is_outbound=0,
 170                                          protocol=socket.IPPROTO_ESP)
 171         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, scapy_tun_sa_id,
 172                                          l_startaddr, l_stopaddr, r_startaddr,
 173                                          r_stopaddr, remote_port_start=4500,
 174                                          remote_port_stop=4500,
 175                                          protocol=socket.IPPROTO_UDP)
 176         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, scapy_tun_sa_id,
 177                                          l_startaddr, l_stopaddr, r_startaddr,
 178                                          r_stopaddr, remote_port_start=4500,
 179                                          remote_port_stop=4500,
 180                                          protocol=socket.IPPROTO_UDP,
 181                                          is_outbound=0)
 182         l_startaddr = l_stopaddr = cls.tun_if.remote_addr_n[addr_type]
 183         r_startaddr = r_stopaddr = cls.pg1.remote_addr_n[addr_type]
 184         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, vpp_tun_sa_id,
 185                                          l_startaddr, l_stopaddr, r_startaddr,
 186                                          r_stopaddr, priority=10, policy=3,
 187                                          is_outbound=0)
 188         cls.vapi.ipsec_spd_add_del_entry(cls.tun_spd_id, scapy_tun_sa_id,
 189                                          r_startaddr, r_stopaddr, l_startaddr,
 190                                          l_stopaddr, priority=10, policy=3)
 191
 192     def test_ipsec_nat_tun(self):
 193         """ IPSec/NAT tunnel test case """
 194         p = self.ipv4_params
 195         scapy_tun_sa = SecurityAssociation(ESP, spi=p.scapy_tun_spi,
 196                                            crypt_algo=p.crypt_algo,
 197                                            crypt_key=p.crypt_key,
 198                                            auth_algo=p.auth_algo,
 199                                            auth_key=p.auth_key,
 200                                            tunnel_header=IP(
 201                                                src=self.pg1.remote_ip4,
 202                                                dst=self.tun_if.remote_ip4),
 203                                            nat_t_header=UDP(
 204                                                sport=4500,
 205                                                dport=4500))
 206         # in2out - from private network to public
 207         pkts = self.create_stream_plain(
 208             self.pg1.remote_mac, self.pg1.local_mac,
 209             self.pg1.remote_ip4, self.tun_if.remote_ip4)
 210         self.pg1.add_stream(pkts)
 211         self.pg_enable_capture(self.pg_interfaces)
 212         self.pg_start()
 213         capture = self.tun_if.get_capture(len(pkts))
 214         self.verify_capture_encrypted(capture, scapy_tun_sa)
 215
 216         vpp_tun_sa = SecurityAssociation(ESP,
 217                                          spi=p.vpp_tun_spi,
 218                                          crypt_algo=p.crypt_algo,
 219                                          crypt_key=p.crypt_key,
 220                                          auth_algo=p.auth_algo,
 221                                          auth_key=p.auth_key,
 222                                          tunnel_header=IP(
 223                                              src=self.tun_if.remote_ip4,
 224                                              dst=self.pg1.remote_ip4),
 225                                          nat_t_header=UDP(
 226                                              sport=4500,
 227                                              dport=4500))
 228
 229         # out2in - from public network to private
 230         pkts = self.create_stream_encrypted(
 231             self.tun_if.remote_mac, self.tun_if.local_mac,
 232             self.tun_if.remote_ip4, self.pg1.remote_ip4, vpp_tun_sa)
 233         self.logger.info(ppc("Sending packets:", pkts))
 234         self.tun_if.add_stream(pkts)
 235         self.pg_enable_capture(self.pg_interfaces)
 236         self.pg_start()
 237         capture = self.pg1.get_capture(len(pkts))
 238         self.verify_capture_plain(capture)