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