+diff --git a/scapy/layers/ipsec.py b/scapy/layers/ipsec.py
+index f8c601fa..f566d288 100644
+--- a/scapy/layers/ipsec.py
++++ b/scapy/layers/ipsec.py
+@@ -359,11 +359,8 @@ class CryptAlgo(object):
+ encryptor = cipher.encryptor()
+
+ if self.is_aead:
+- if esn_en:
+- aad = struct.pack('!LLL', esp.spi, esn, esp.seq)
+- else:
+- aad = struct.pack('!LL', esp.spi, esp.seq)
+- encryptor.authenticate_additional_data(aad)
++ encryptor.authenticate_additional_data(sa.build_aead(esp))
++
+ data = encryptor.update(data) + encryptor.finalize()
+ data += encryptor.tag[:self.icv_size]
+ else:
+@@ -401,12 +398,7 @@ class CryptAlgo(object):
+
+ if self.is_aead:
+ # Tag value check is done during the finalize method
+- if esn_en:
+- decryptor.authenticate_additional_data(
+- struct.pack('!LLL', esp.spi, esn, esp.seq))
+- else:
+- decryptor.authenticate_additional_data(
+- struct.pack('!LL', esp.spi, esp.seq))
++ decryptor.authenticate_additional_data(sa.build_aead(esp))
+ try:
+ data = decryptor.update(data) + decryptor.finalize()
+ except InvalidTag as err:
+@@ -545,7 +537,7 @@ class AuthAlgo(object):
+ else:
+ return self.mac(key, self.digestmod(), default_backend())
+
+- def sign(self, pkt, key):
++ def sign(self, pkt, key, trailer=None):
+ """
+ Sign an IPsec (ESP or AH) packet with this algo.
+
+@@ -561,16 +553,20 @@ class AuthAlgo(object):
+
+ if pkt.haslayer(ESP):
+ mac.update(raw(pkt[ESP]))
++ if trailer:
++ mac.update(trailer)
+ pkt[ESP].data += mac.finalize()[:self.icv_size]
+
+ elif pkt.haslayer(AH):
+ clone = zero_mutable_fields(pkt.copy(), sending=True)
+ mac.update(raw(clone))
++ if trailer:
++ mac.update(trailer)
+ pkt[AH].icv = mac.finalize()[:self.icv_size]
+
+ return pkt
+
+- def verify(self, pkt, key):
++ def verify(self, pkt, key, trailer):
+ """
+ Check that the integrity check value (icv) of a packet is valid.
+
+@@ -602,6 +598,8 @@ class AuthAlgo(object):
+ clone = zero_mutable_fields(pkt.copy(), sending=False)
+
+ mac.update(raw(clone))
++ if trailer:
++ mac.update(trailer) # bytearray(4)) #raw(trailer))
+ computed_icv = mac.finalize()[:self.icv_size]
+
+ # XXX: Cannot use mac.verify because the ICV can be truncated
+@@ -864,6 +862,23 @@ class SecurityAssociation(object):
+ raise TypeError('nat_t_header must be %s' % UDP.name)
+ self.nat_t_header = nat_t_header
+
++ def build_aead(self, esp):
++ if self.esn_en:
++ return (struct.pack('!LLL', esp.spi, self.seq_num >> 32, esp.seq))
++ else:
++ return (struct.pack('!LL', esp.spi, esp.seq))
++
++ def build_seq_num(self, num):
++ # only lower order bits are transmitted
++ # higher order bits are used in the ICV
++ lower = num & 0xffffffff
++ upper = num >> 32
++
++ if self.esn_en:
++ return lower, struct.pack("!I", upper)
++ else:
++ return lower, None
++
+ def check_spi(self, pkt):
+ if pkt.spi != self.spi:
+ raise TypeError('packet spi=0x%x does not match the SA spi=0x%x' %
+@@ -877,7 +892,8 @@ class SecurityAssociation(object):
+ if len(iv) != self.crypt_algo.iv_size:
+ raise TypeError('iv length must be %s' % self.crypt_algo.iv_size) # noqa: E501
+
+- esp = _ESPPlain(spi=self.spi, seq=seq_num or self.seq_num, iv=iv)
++ low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
++ esp = _ESPPlain(spi=self.spi, seq=low_seq_num, iv=iv)
+
+ if self.tunnel_header:
+ tunnel = self.tunnel_header.copy()
+@@ -901,7 +917,7 @@ class SecurityAssociation(object):
+ esn_en=esn_en or self.esn_en,
+ esn=esn or self.esn)
+
+- self.auth_algo.sign(esp, self.auth_key)
++ self.auth_algo.sign(esp, self.auth_key, high_seq_num)
+
+ if self.nat_t_header:
+ nat_t_header = self.nat_t_header.copy()
+@@ -928,7 +944,8 @@ class SecurityAssociation(object):
+
+ def _encrypt_ah(self, pkt, seq_num=None):
+
+- ah = AH(spi=self.spi, seq=seq_num or self.seq_num,
++ low_seq_num, high_seq_num = self.build_seq_num(seq_num or self.seq_num)
++ ah = AH(spi=self.spi, seq=low_seq_num,
+ icv=b"\x00" * self.auth_algo.icv_size)
+
+ if self.tunnel_header:
+@@ -968,7 +985,8 @@ class SecurityAssociation(object):
+ else:
+ ip_header.plen = len(ip_header.payload) + len(ah) + len(payload)
+
+- signed_pkt = self.auth_algo.sign(ip_header / ah / payload, self.auth_key) # noqa: E501
++ signed_pkt = self.auth_algo.sign(ip_header / ah / payload,
++ self.auth_key, high_seq_num) # noqa: E501
+
+ # sequence number must always change, unless specified by the user
+ if seq_num is None:
+@@ -1005,11 +1023,12 @@ class SecurityAssociation(object):
+
+ def _decrypt_esp(self, pkt, verify=True, esn_en=None, esn=None):
+
++ low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
+ encrypted = pkt[ESP]
+
+ if verify:
+ self.check_spi(pkt)
+- self.auth_algo.verify(encrypted, self.auth_key)
++ self.auth_algo.verify(encrypted, self.auth_key, high_seq_num)
+
+ esp = self.crypt_algo.decrypt(self, encrypted, self.crypt_key,
+ self.crypt_algo.icv_size or
+@@ -1050,9 +1069,10 @@ class SecurityAssociation(object):
+
+ def _decrypt_ah(self, pkt, verify=True):
+
++ low_seq_num, high_seq_num = self.build_seq_num(self.seq_num)
+ if verify:
+ self.check_spi(pkt)
+- self.auth_algo.verify(pkt, self.auth_key)
++ self.auth_algo.verify(pkt, self.auth_key, high_seq_num)
+
+ ah = pkt[AH]
+ payload = ah.payload
+
Code Review / vpp.git / commitdiff