Class SMB2_Negotiate_Protocol_Request

scapy/layers/smb2.py:2191–2247

class SMB2_Negotiate_Protocol_Request(_SMB2_Payload, _NTLMPayloadPacket):
    name = "SMB2 Negotiate Protocol Request"
    Command = 0x0000
    _NTLM_PAYLOAD_FIELD_NAME = "Buffer"
    fields_desc = [
        XLEShortField("StructureSize", 0x24),
        FieldLenField("DialectCount", None, fmt="<H", count_of="Dialects"),
        # SecurityMode
        FlagsField("SecurityMode", 0, -16, SMB2_SECURITY_MODE),
        LEShortField("Reserved", 0),
        # Capabilities
        FlagsField("Capabilities", 0, -32, SMB2_CAPABILITIES),
        UUIDField("ClientGUID", 0x0, uuid_fmt=UUIDField.FORMAT_LE),
        XLEIntField("NegotiateContextsBufferOffset", None),
        LEShortField("NegotiateContextsCount", None),
        ShortField("Reserved2", 0),
        FieldListField(
            "Dialects",
            [0x0202],
            LEShortEnumField("", 0x0, SMB_DIALECTS),
            count_from=lambda pkt: pkt.DialectCount,
        ),
        _NTLMPayloadField(
            "Buffer",
            lambda pkt: 64 + 36 + len(pkt.Dialects) * 2,
            [
                # Field only exists if Dialects contains 0x0311
                FieldListField(
                    "NegotiateContexts",
                    [],
                    ReversePadField(
                        PacketField("Context", None, SMB2_Negotiate_Context),
                        8,
                    ),
                    count_from=lambda pkt: pkt.NegotiateContextsCount,
                ),
            ],
        ),
    ]

    def post_build(self, pkt, pay):
        # type: (bytes, bytes) -> bytes
        return (
            _NTLM_post_build(
                self,
                pkt,
                64 + 36 + len(self.Dialects) * 2,
                {
                    "NegotiateContexts": 28,
                },
                config=[
                    ("BufferOffset", _NTLM_ENUM.OFFSET | _NTLM_ENUM.PAD8),
                    ("Count", _NTLM_ENUM.COUNT),
                ],
            )
            + pay
        )