diff options
Diffstat (limited to 'net/test/xfrm_base.py')
| -rw-r--r-- | net/test/xfrm_base.py | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/net/test/xfrm_base.py b/net/test/xfrm_base.py index 06e8cf2..e5aadf3 100644 --- a/net/test/xfrm_base.py +++ b/net/test/xfrm_base.py @@ -143,6 +143,18 @@ def GetEspPacketLength(mode, version, udp_encap, payload, return payload_len +def GetEspTrailer(length, nexthdr): + # ESP padding per RFC 4303 section 2.4. + # For a null cipher with a block size of 1, padding is only necessary to + # ensure that the 1-byte Pad Length and Next Header fields are right aligned + # on a 4-byte boundary. + esplen = length + 2 # Packet length plus Pad Length and Next Header. + padlen = util.GetPadLength(4, esplen) + # The pad bytes are consecutive integers starting from 0x01. + padding = "".join((chr(i) for i in range(1, padlen + 1))).encode("utf-8") + return padding + struct.pack("BB", padlen, nexthdr) + + def EncryptPacketWithNull(packet, spi, seq, tun_addrs): """Apply null encryption to a packet. @@ -189,16 +201,7 @@ def EncryptPacketWithNull(packet, spi, seq, tun_addrs): inner_layer = udp_layer esp_nexthdr = IPPROTO_UDP - - # ESP padding per RFC 4303 section 2.4. - # For a null cipher with a block size of 1, padding is only necessary to - # ensure that the 1-byte Pad Length and Next Header fields are right aligned - # on a 4-byte boundary. - esplen = (len(inner_layer) + 2) # UDP length plus Pad Length and Next Header. - padlen = util.GetPadLength(4, esplen) - # The pad bytes are consecutive integers starting from 0x01. - padding = "".join((chr(i) for i in range(1, padlen + 1))).encode("utf-8") - trailer = padding + struct.pack("BB", padlen, esp_nexthdr) + trailer = GetEspTrailer(len(inner_layer), esp_nexthdr) # Assemble the packet. esp_packet.payload = scapy.Raw(inner_layer) |