test/patches/scapy-2.4.3/ipsec.patch

   1 diff --git a/scapy/layers/ipsec.py b/scapy/layers/ipsec.py
   2 index ae057ee1..b6806f71 100644
   3 --- a/scapy/layers/ipsec.py
   4 +++ b/scapy/layers/ipsec.py
   5 @@ -56,6 +56,7 @@ from scapy.fields import ByteEnumField, ByteField, IntField, PacketField, \
   6      ShortField, StrField, XIntField, XStrField, XStrLenField
   7  from scapy.packet import Packet, bind_layers, Raw
   8  from scapy.layers.inet import IP, UDP
   9 +from scapy.contrib.mpls import MPLS
  10  import scapy.modules.six as six
  11  from scapy.modules.six.moves import range
  12  from scapy.layers.inet6 import IPv6, IPv6ExtHdrHopByHop, IPv6ExtHdrDestOpt, \
  13 @@ -359,13 +360,17 @@ 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 +                aad = sa.build_aead(esp)
  22 +                if self.name == 'AES-NULL-GMAC':
  23 +                    aad = aad + esp.iv + data
  24 +                    aes_null_gmac_data = data
  25 +                    data = b''
  26                  encryptor.authenticate_additional_data(aad)
  27 +
  28                  data = encryptor.update(data) + encryptor.finalize()
  29                  data += encryptor.tag[:self.icv_size]
  30 +                if self.name == 'AES-NULL-GMAC':
  31 +                    data = aes_null_gmac_data + data
  32              else:
  33                  data = encryptor.update(data) + encryptor.finalize()
  34
  35 @@ -399,17 +404,19 @@ class CryptAlgo(object):
  36              decryptor = cipher.decryptor()
  37
  38              if self.is_aead:
  39 +                aad = sa.build_aead(esp)
  40 +                if self.name == 'AES-NULL-GMAC':
  41 +                    aad = aad + iv + data
  42 +                    aes_null_gmac_data = data
  43 +                    data = b''
  44                  # Tag value check is done during the finalize method
  45 -                if esn_en:
  46 -                    decryptor.authenticate_additional_data(
  47 -                        struct.pack('!LLL', esp.spi, esn, esp.seq))
  48 -                else:
  49 -                    decryptor.authenticate_additional_data(
  50 -                        struct.pack('!LL', esp.spi, esp.seq))
  51 +                decryptor.authenticate_additional_data(aad)
  52              try:
  53                  data = decryptor.update(data) + decryptor.finalize()
  54              except InvalidTag as err:
  55                  raise IPSecIntegrityError(err)
  56 +            if self.name == 'AES-NULL-GMAC':
  57 +                data = aes_null_gmac_data + data
  58
  59          # extract padlen and nh
  60          padlen = orb(data[-2])
  61 @@ -445,6 +452,7 @@ if algorithms:
  62      CRYPT_ALGOS['AES-CTR'] = CryptAlgo('AES-CTR',
  63                                         cipher=algorithms.AES,
  64                                         mode=modes.CTR,
  65 +                                       block_size=1,
  66                                         iv_size=8,
  67                                         salt_size=4,
  68                                         format_mode_iv=_aes_ctr_format_mode_iv)
  69 @@ -452,14 +460,24 @@ if algorithms:
  70      CRYPT_ALGOS['AES-GCM'] = CryptAlgo('AES-GCM',
  71                                         cipher=algorithms.AES,
  72                                         mode=modes.GCM,
  73 +                                       block_size=1,
  74                                         salt_size=4,
  75                                         iv_size=8,
  76                                         icv_size=16,
  77                                         format_mode_iv=_salt_format_mode_iv)
  78 +    CRYPT_ALGOS['AES-NULL-GMAC'] = CryptAlgo('AES-NULL-GMAC',
  79 +                                             cipher=algorithms.AES,
  80 +                                             mode=modes.GCM,
  81 +                                             block_size=1,
  82 +                                             salt_size=4,
  83 +                                             iv_size=8,
  84 +                                             icv_size=16,
  85 +                                             format_mode_iv=_salt_format_mode_iv)
  86      if hasattr(modes, 'CCM'):
  87          CRYPT_ALGOS['AES-CCM'] = CryptAlgo('AES-CCM',
  88                                             cipher=algorithms.AES,
  89                                             mode=modes.CCM,
  90 +                                           block_size=1,
  91                                             iv_size=8,
  92                                             salt_size=3,
  93                                             icv_size=16,
  94 @@ -544,7 +562,7 @@ class AuthAlgo(object):
  95          else:
  96              return self.mac(key, self.digestmod(), default_backend())
  97
  98 -    def sign(self, pkt, key):
  99 +    def sign(self, pkt, key, trailer=None):
 100          """
 101          Sign an IPsec (ESP or AH) packet with this algo.
 102
 103 @@ -560,16 +578,20 @@ class AuthAlgo(object):
 104
 105          if pkt.haslayer(ESP):
 106              mac.update(raw(pkt[ESP]))
 107 +            if trailer:
 108 +                mac.update(trailer)
 109              pkt[ESP].data += mac.finalize()[:self.icv_size]
 110
 111          elif pkt.haslayer(AH):
 112              clone = zero_mutable_fields(pkt.copy(), sending=True)
 113              mac.update(raw(clone))
 114 +            if trailer:
 115 +                mac.update(trailer)
 116              pkt[AH].icv = mac.finalize()[:self.icv_size]
 117
 118          return pkt
 119
 120 -    def verify(self, pkt, key):
 121 +    def verify(self, pkt, key, trailer):
 122          """
 123          Check that the integrity check value (icv) of a packet is valid.
 124
 125 @@ -600,6 +622,8 @@ class AuthAlgo(object):
 126              clone = zero_mutable_fields(pkt.copy(), sending=False)
 127
 128          mac.update(raw(clone))
 129 +        if trailer:
 130 +            mac.update(trailer) # bytearray(4)) #raw(trailer))
 131          computed_icv = mac.finalize()[:self.icv_size]
 132
 133          # XXX: Cannot use mac.verify because the ICV can be truncated
 134 @@ -788,7 +812,7 @@ class SecurityAssociation(object):
 135      This class is responsible of "encryption" and "decryption" of IPsec packets.  # noqa: E501
 136      """
 137
 138 -    SUPPORTED_PROTOS = (IP, IPv6)
 139 +    SUPPORTED_PROTOS = (IP, IPv6, MPLS)
 140
 141      def __init__(self, proto, spi, seq_num=1, crypt_algo=None, crypt_key=None,
 142                   auth_algo=None, auth_key=None, tunnel_header=None, nat_t_header=None, esn_en=False, esn=0):   # noqa: E501
 143 @@ -862,6 +886,23 @@ class SecurityAssociation(object):
 144                  raise TypeError('nat_t_header must be %s' % UDP.name)
 145          self.nat_t_header = nat_t_header
 146
 147 +    def build_aead(self, esp):
 148 +        if self.esn_en:
 149 +            return (struct.pack('!LLL', esp.spi, self.seq_num >> 32, esp.seq))
 150 +        else:
 151 +            return (struct.pack('!LL', esp.spi, esp.seq))
 152 +
 153 +    def build_seq_num(self, num):
 154 +        # only lower order bits are  transmitted
 155 +        # higher order bits are used in the ICV
 156 +        lower = num & 0xffffffff
 157 +        upper = num >> 32
 158 +
 159 +        if self.esn_en:
 160 +            return lower, struct.pack("!I", upper)
 161 +        else:
 162 +            return lower, None
 163 +
 164      def check_spi(self, pkt):
 165          if pkt.spi != self.spi:
 166              raise TypeError('packet spi=0x%x does not match the SA spi=0x%x' %
 167 @@ -875,7 +916,8 @@ class SecurityAssociation(object):
 168              if len(iv) != self.crypt_algo.iv_size:
 169                  raise TypeError('iv length must be %s' % self.crypt_algo.iv_size)  # noqa: E501
 170
 171 -        esp = _ESPPlain(spi=self.spi, seq=seq_num or self.seq_num, iv=iv)
 172 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 173 +        esp = _ESPPlain(spi=self.spi, seq=low_seq_num, iv=iv)
 174
 175          if self.tunnel_header:
 176              tunnel = self.tunnel_header.copy()
 177 @@ -899,7 +941,7 @@ class SecurityAssociation(object):
 178                                        esn_en=esn_en or self.esn_en,
 179                                        esn=esn or self.esn)
 180
 181 -        self.auth_algo.sign(esp, self.auth_key)
 182 +        self.auth_algo.sign(esp, self.auth_key, high_seq_num)
 183
 184          if self.nat_t_header:
 185              nat_t_header = self.nat_t_header.copy()
 186 @@ -926,7 +968,8 @@ class SecurityAssociation(object):
 187
 188      def _encrypt_ah(self, pkt, seq_num=None):
 189
 190 -        ah = AH(spi=self.spi, seq=seq_num or self.seq_num,
 191 +        low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
 192 +        ah = AH(spi=self.spi, seq=low_seq_num,
 193                  icv=b"\x00" * self.auth_algo.icv_size)
 194
 195          if self.tunnel_header:
 196 @@ -966,7 +1009,8 @@ class SecurityAssociation(object):
 197          else:
 198              ip_header.plen = len(ip_header.payload) + len(ah) + len(payload)
 199
 200 -        signed_pkt = self.auth_algo.sign(ip_header / ah / payload, self.auth_key)  # noqa: E501
 201 +        signed_pkt = self.auth_algo.sign(ip_header / ah / payload,
 202 +                                         self.auth_key, high_seq_num)  # noqa: E501
 203
 204          # sequence number must always change, unless specified by the user
 205          if seq_num is None:
 206 @@ -1003,11 +1047,12 @@ class SecurityAssociation(object):
 207
 208      def _decrypt_esp(self, pkt, verify=True, esn_en=None, esn=None):
 209
 210 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 211          encrypted = pkt[ESP]
 212
 213          if verify:
 214              self.check_spi(pkt)
 215 -            self.auth_algo.verify(encrypted, self.auth_key)
 216 +            self.auth_algo.verify(encrypted, self.auth_key, high_seq_num)
 217
 218          esp = self.crypt_algo.decrypt(self, encrypted, self.crypt_key,
 219                                        self.crypt_algo.icv_size or
 220 @@ -1048,9 +1093,10 @@ class SecurityAssociation(object):
 221
 222      def _decrypt_ah(self, pkt, verify=True):
 223
 224 +        low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
 225          if verify:
 226              self.check_spi(pkt)
 227 -            self.auth_algo.verify(pkt, self.auth_key)
 228 +            self.auth_algo.verify(pkt, self.auth_key, high_seq_num)
 229
 230          ah = pkt[AH]
 231          payload = ah.payload