test/patches/scapy-2.4/ipsec.patch

   1 diff --git a/scapy/layers/ipsec.py b/scapy/layers/ipsec.py
   2 index 69e7ae3b..d9c1705b 100644
   3 --- a/scapy/layers/ipsec.py
   4 +++ b/scapy/layers/ipsec.py
   5 @@ -344,8 +344,7 @@ class CryptAlgo(object):
   6              encryptor = cipher.encryptor()
   7
   8              if self.is_aead:
   9 -                aad = struct.pack('!LL', esp.spi, esp.seq)
  10 -                encryptor.authenticate_additional_data(aad)
  11 +                encryptor.authenticate_additional_data(sa.build_aead(esp))
  12                  data = encryptor.update(data) + encryptor.finalize()
  13                  data += encryptor.tag[:self.icv_size]
  14              else:
  15 @@ -380,10 +379,7 @@ class CryptAlgo(object):
  16
  17              if self.is_aead:
  18                  # Tag value check is done during the finalize method
  19 -                decryptor.authenticate_additional_data(
  20 -                    struct.pack('!LL', esp.spi, esp.seq)
  21 -                )
  22 -
  23 +                decryptor.authenticate_additional_data(sa.build_aead(esp))
  24              try:
  25                  data = decryptor.update(data) + decryptor.finalize()
  26              except InvalidTag as err:
  27 @@ -422,6 +418,7 @@ if algorithms:
  28      CRYPT_ALGOS['AES-CTR'] = CryptAlgo('AES-CTR',
  29                                         cipher=algorithms.AES,
  30                                         mode=modes.CTR,
  31 +                                       block_size=1,
  32                                         iv_size=8,
  33                                         salt_size=4,
  34                                         format_mode_iv=_aes_ctr_format_mode_iv)
  35 @@ -429,6 +426,7 @@ if algorithms:
  36      CRYPT_ALGOS['AES-GCM'] = CryptAlgo('AES-GCM',
  37                                         cipher=algorithms.AES,
  38                                         mode=modes.GCM,
  39 +                                       block_size=1,
  40                                         salt_size=4,
  41                                         iv_size=8,
  42                                         icv_size=16,
  43 @@ -437,6 +435,7 @@ if algorithms:
  44          CRYPT_ALGOS['AES-CCM'] = CryptAlgo('AES-CCM',
  45                                             cipher=algorithms.AES,
  46                                             mode=modes.CCM,
  47 +                                           block_size=1,
  48                                             iv_size=8,
  49                                             salt_size=3,
  50                                             icv_size=16,
  51 @@ -518,12 +517,16 @@ class AuthAlgo(object):
  52          else:
  53              return self.mac(key, self.digestmod(), default_backend())
  54
  55 -    def sign(self, pkt, key):
  56 +    def sign(self, pkt, key, trailer=None):
  57          """
  58          Sign an IPsec (ESP or AH) packet with this algo.
  59
  60          @param pkt:    a packet that contains a valid encrypted ESP or AH layer
  61          @param key:    the authentication key, a byte string
  62 +        @param trailer: additional data appended to the packet for ICV
  63 +                        calculation, but not trnasmitted with the packet.
  64 +                        For example, the high order bits of the exteneded
  65 +                        sequence number.
  66
  67          @return: the signed packet
  68          """
  69 @@ -534,16 +537,20 @@ class AuthAlgo(object):
  70
  71          if pkt.haslayer(ESP):
  72              mac.update(raw(pkt[ESP]))
  73 +            if trailer:
  74 +                mac.update(trailer)
  75              pkt[ESP].data += mac.finalize()[:self.icv_size]
  76
  77          elif pkt.haslayer(AH):
  78              clone = zero_mutable_fields(pkt.copy(), sending=True)
  79              mac.update(raw(clone))
  80 +            if trailer:
  81 +                mac.update(trailer)
  82              pkt[AH].icv = mac.finalize()[:self.icv_size]
  83
  84          return pkt
  85
  86 -    def verify(self, pkt, key):
  87 +    def verify(self, pkt, key, trailer):
  88          """
  89          Check that the integrity check value (icv) of a packet is valid.
  90
  91 @@ -574,6 +581,8 @@ class AuthAlgo(object):
  92              clone = zero_mutable_fields(pkt.copy(), sending=False)
  93
  94          mac.update(raw(clone))
  95 +        if trailer:
  96 +            mac.update(trailer) # bytearray(4)) #raw(trailer))
  97          computed_icv = mac.finalize()[:self.icv_size]
  98
  99          # XXX: Cannot use mac.verify because the ICV can be truncated
 100 @@ -757,7 +766,8 @@ class SecurityAssociation(object):
 101      SUPPORTED_PROTOS = (IP, IPv6)
 102
 103      def __init__(self, proto, spi, seq_num=1, crypt_algo=None, crypt_key=None,
 104 -                 auth_algo=None, auth_key=None, tunnel_header=None, nat_t_header=None):
 105 +                 auth_algo=None, auth_key=None, tunnel_header=None, nat_t_header=None,
 106 +                 use_esn=False):
 107          """
 108          @param proto: the IPsec proto to use (ESP or AH)
 109          @param spi: the Security Parameters Index of this SA
 110 @@ -771,6 +781,7 @@ class SecurityAssociation(object):
 111                                to encapsulate the encrypted packets.
 112          @param nat_t_header: an instance of a UDP header that will be used
 113                               for NAT-Traversal.
 114 +        @param use_esn: Use Extended Sequence Numbers
 115          """
 116
 117          if proto not in (ESP, AH, ESP.name, AH.name):
 118 @@ -782,6 +793,7 @@ class SecurityAssociation(object):
 119
 120          self.spi = spi
 121          self.seq_num = seq_num
 122 +        self.use_esn = use_esn
 123
 124          if crypt_algo:
 125              if crypt_algo not in CRYPT_ALGOS:
 126 @@ -827,6 +839,23 @@ class SecurityAssociation(object):
 127              raise TypeError('packet spi=0x%x does not match the SA spi=0x%x' %
 128                              (pkt.spi, self.spi))
 129
 130 +    def build_aead(self, esp):
 131 +        if self.use_esn:
 132 +            return (struct.pack('!LLL', esp.spi, self.seq_num >> 32, esp.seq))
 133 +        else:
 134 +            return (struct.pack('!LL', esp.spi, esp.seq))
 135 +
 136 +    def build_seq_num(self, num):
 137 +        # only lower order bits are  transmitted
 138 +        # higher order bits are used in the ICV
 139 +        lower = num & 0xffffffff
 140 +        upper = num >> 32
 141 +
 142 +        if self.use_esn:
 143 +            return lower, struct.pack("!I", upper)
 144 +        else:
 145 +            return lower, None
 146 +
 147      def _encrypt_esp(self, pkt, seq_num=None, iv=None):
 148
 149          if iv is None:
 150 @@ -835,7 +864,8 @@ class SecurityAssociation(object):
 151              if len(iv) != self.crypt_algo.iv_size:
 152                  raise TypeError('iv length must be %s' % self.crypt_algo.iv_size)
 153
 154 -        esp = _ESPPlain(spi=self.spi, seq=seq_num or self.seq_num, iv=iv)
 155 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 156 +        esp = _ESPPlain(spi=self.spi, seq=low_seq_num, iv=iv)
 157
 158          if self.tunnel_header:
 159              tunnel = self.tunnel_header.copy()
 160 @@ -857,7 +887,7 @@ class SecurityAssociation(object):
 161          esp = self.crypt_algo.pad(esp)
 162          esp = self.crypt_algo.encrypt(self, esp, self.crypt_key)
 163
 164 -        self.auth_algo.sign(esp, self.auth_key)
 165 +        self.auth_algo.sign(esp, self.auth_key, high_seq_num)
 166
 167          if self.nat_t_header:
 168              nat_t_header = self.nat_t_header.copy()
 169 @@ -884,7 +914,8 @@ class SecurityAssociation(object):
 170
 171      def _encrypt_ah(self, pkt, seq_num=None):
 172
 173 -        ah = AH(spi=self.spi, seq=seq_num or self.seq_num,
 174 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 175 +        ah = AH(spi=self.spi, seq=low_seq_num,
 176                  icv = b"\x00" * self.auth_algo.icv_size)
 177
 178          if self.tunnel_header:
 179 @@ -924,7 +955,8 @@ class SecurityAssociation(object):
 180          else:
 181              ip_header.plen = len(ip_header.payload) + len(ah) + len(payload)
 182
 183 -        signed_pkt = self.auth_algo.sign(ip_header / ah / payload, self.auth_key)
 184 +        signed_pkt = self.auth_algo.sign(ip_header / ah / payload,
 185 +                                         self.auth_key, high_seq_num)
 186
 187          # sequence number must always change, unless specified by the user
 188          if seq_num is None:
 189 @@ -955,11 +987,12 @@ class SecurityAssociation(object):
 190
 191      def _decrypt_esp(self, pkt, verify=True):
 192
 193 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 194          encrypted = pkt[ESP]
 195
 196          if verify:
 197              self.check_spi(pkt)
 198 -            self.auth_algo.verify(encrypted, self.auth_key)
 199 +            self.auth_algo.verify(encrypted, self.auth_key, high_seq_num)
 200
 201          esp = self.crypt_algo.decrypt(self, encrypted, self.crypt_key,
 202                                        self.crypt_algo.icv_size or
 203 @@ -998,9 +1031,11 @@ class SecurityAssociation(object):
 204
 205      def _decrypt_ah(self, pkt, verify=True):
 206
 207 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 208 +
 209          if verify:
 210              self.check_spi(pkt)
 211 -            self.auth_algo.verify(pkt, self.auth_key)
 212 +            self.auth_algo.verify(pkt, self.auth_key, high_seq_num)
 213
 214          ah = pkt[AH]
 215          payload = ah.payload