test/patches/scapy-2.4.3/ipsec.patch

   1 diff --git a/scapy/layers/ipsec.py b/scapy/layers/ipsec.py
   2 index f8c601fa..f566d288 100644
   3 --- a/scapy/layers/ipsec.py
   4 +++ b/scapy/layers/ipsec.py
   5 @@ -138,6 +138,7 @@ bind_layers(IP, ESP, proto=socket.IPPROTO_ESP)
   6  bind_layers(IPv6, ESP, nh=socket.IPPROTO_ESP)
   7  bind_layers(UDP, ESP, dport=4500)  # NAT-Traversal encapsulation
   8  bind_layers(UDP, ESP, sport=4500)  # NAT-Traversal encapsulation
   9 +bind_layers(UDP, ESP, dport=4545)  # NAT-Traversal encapsulation - random port
  10
  11  ###############################################################################
  12
  13 @@ -359,11 +359,8 @@ class CryptAlgo(object):
  14              encryptor = cipher.encryptor()
  15
  16              if self.is_aead:
  17 -                if esn_en:
  18 -                    aad = struct.pack('!LLL', esp.spi, esn, esp.seq)
  19 -                else:
  20 -                    aad = struct.pack('!LL', esp.spi, esp.seq)
  21 -                encryptor.authenticate_additional_data(aad)
  22 +                encryptor.authenticate_additional_data(sa.build_aead(esp))
  23 +
  24                  data = encryptor.update(data) + encryptor.finalize()
  25                  data += encryptor.tag[:self.icv_size]
  26              else:
  27 @@ -401,12 +398,7 @@ class CryptAlgo(object):
  28
  29              if self.is_aead:
  30                  # Tag value check is done during the finalize method
  31 -                if esn_en:
  32 -                    decryptor.authenticate_additional_data(
  33 -                        struct.pack('!LLL', esp.spi, esn, esp.seq))
  34 -                else:
  35 -                    decryptor.authenticate_additional_data(
  36 -                        struct.pack('!LL', esp.spi, esp.seq))
  37 +                decryptor.authenticate_additional_data(sa.build_aead(esp))
  38              try:
  39                  data = decryptor.update(data) + decryptor.finalize()
  40              except InvalidTag as err:
  41 @@ -545,7 +537,7 @@ class AuthAlgo(object):
  42          else:
  43              return self.mac(key, self.digestmod(), default_backend())
  44
  45 -    def sign(self, pkt, key):
  46 +    def sign(self, pkt, key, trailer=None):
  47          """
  48          Sign an IPsec (ESP or AH) packet with this algo.
  49
  50 @@ -561,16 +553,20 @@ class AuthAlgo(object):
  51
  52          if pkt.haslayer(ESP):
  53              mac.update(raw(pkt[ESP]))
  54 +            if trailer:
  55 +                mac.update(trailer)
  56              pkt[ESP].data += mac.finalize()[:self.icv_size]
  57
  58          elif pkt.haslayer(AH):
  59              clone = zero_mutable_fields(pkt.copy(), sending=True)
  60              mac.update(raw(clone))
  61 +            if trailer:
  62 +                mac.update(trailer)
  63              pkt[AH].icv = mac.finalize()[:self.icv_size]
  64
  65          return pkt
  66
  67 -    def verify(self, pkt, key):
  68 +    def verify(self, pkt, key, trailer):
  69          """
  70          Check that the integrity check value (icv) of a packet is valid.
  71
  72 @@ -602,6 +598,8 @@ class AuthAlgo(object):
  73              clone = zero_mutable_fields(pkt.copy(), sending=False)
  74
  75          mac.update(raw(clone))
  76 +        if trailer:
  77 +            mac.update(trailer) # bytearray(4)) #raw(trailer))
  78          computed_icv = mac.finalize()[:self.icv_size]
  79
  80          # XXX: Cannot use mac.verify because the ICV can be truncated
  81 @@ -864,6 +862,23 @@ class SecurityAssociation(object):
  82                  raise TypeError('nat_t_header must be %s' % UDP.name)
  83          self.nat_t_header = nat_t_header
  84
  85 +    def build_aead(self, esp):
  86 +        if self.esn_en:
  87 +            return (struct.pack('!LLL', esp.spi, self.seq_num >> 32, esp.seq))
  88 +        else:
  89 +            return (struct.pack('!LL', esp.spi, esp.seq))
  90 +
  91 +    def build_seq_num(self, num):
  92 +        # only lower order bits are  transmitted
  93 +        # higher order bits are used in the ICV
  94 +        lower = num & 0xffffffff
  95 +        upper = num >> 32
  96 +
  97 +        if self.esn_en:
  98 +            return lower, struct.pack("!I", upper)
  99 +        else:
 100 +            return lower, None
 101 +
 102      def check_spi(self, pkt):
 103          if pkt.spi != self.spi:
 104              raise TypeError('packet spi=0x%x does not match the SA spi=0x%x' %
 105 @@ -877,7 +892,8 @@ class SecurityAssociation(object):
 106              if len(iv) != self.crypt_algo.iv_size:
 107                  raise TypeError('iv length must be %s' % self.crypt_algo.iv_size)  # noqa: E501
 108
 109 -        esp = _ESPPlain(spi=self.spi, seq=seq_num or self.seq_num, iv=iv)
 110 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 111 +        esp = _ESPPlain(spi=self.spi, seq=low_seq_num, iv=iv)
 112
 113          if self.tunnel_header:
 114              tunnel = self.tunnel_header.copy()
 115 @@ -901,7 +917,7 @@ class SecurityAssociation(object):
 116                                        esn_en=esn_en or self.esn_en,
 117                                        esn=esn or self.esn)
 118
 119 -        self.auth_algo.sign(esp, self.auth_key)
 120 +        self.auth_algo.sign(esp, self.auth_key, high_seq_num)
 121
 122          if self.nat_t_header:
 123              nat_t_header = self.nat_t_header.copy()
 124 @@ -928,7 +944,8 @@ class SecurityAssociation(object):
 125
 126      def _encrypt_ah(self, pkt, seq_num=None):
 127
 128 -        ah = AH(spi=self.spi, seq=seq_num or self.seq_num,
 129 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 130 +        ah = AH(spi=self.spi, seq=low_seq_num,
 131                  icv=b"\x00" * self.auth_algo.icv_size)
 132
 133          if self.tunnel_header:
 134 @@ -968,7 +985,8 @@ class SecurityAssociation(object):
 135          else:
 136              ip_header.plen = len(ip_header.payload) + len(ah) + len(payload)
 137
 138 -        signed_pkt = self.auth_algo.sign(ip_header / ah / payload, self.auth_key)  # noqa: E501
 139 +        signed_pkt = self.auth_algo.sign(ip_header / ah / payload,
 140 +                                         self.auth_key, high_seq_num)  # noqa: E501
 141
 142          # sequence number must always change, unless specified by the user
 143          if seq_num is None:
 144 @@ -1005,11 +1023,12 @@ class SecurityAssociation(object):
 145
 146      def _decrypt_esp(self, pkt, verify=True, esn_en=None, esn=None):
 147
 148 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 149          encrypted = pkt[ESP]
 150
 151          if verify:
 152              self.check_spi(pkt)
 153 -            self.auth_algo.verify(encrypted, self.auth_key)
 154 +            self.auth_algo.verify(encrypted, self.auth_key, high_seq_num)
 155
 156          esp = self.crypt_algo.decrypt(self, encrypted, self.crypt_key,
 157                                        self.crypt_algo.icv_size or
 158 @@ -1050,11 +1069,12 @@ class SecurityAssociation(object):
 159
 160      def _decrypt_ah(self, pkt, verify=True):
 161
 162 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 163          if verify:
 164              self.check_spi(pkt)
 165 -            self.auth_algo.verify(pkt, self.auth_key)
 166 +            self.auth_algo.verify(pkt, self.auth_key, high_seq_num)
 167
 168          ah = pkt[AH]
 169          payload = ah.payload
 170
 171