Beginnings of a Skype dissector. Requires "decode as".
svn path=/trunk/; revision=44412
This commit is contained in:
Jörg Mayer
parent
5f1b2bd6ed
commit
94b65da547
|
|
@ -1083,6 +1083,7 @@ set(DISSECTOR_SRC
|
|||
dissectors/packet-sipfrag.c
|
||||
dissectors/packet-sita.c
|
||||
dissectors/packet-skinny.c
|
||||
dissectors/packet-skype.c
|
||||
dissectors/packet-slimp3.c
|
||||
dissectors/packet-sll.c
|
||||
dissectors/packet-slowprotocols.c
|
||||
|
|
|
|||
|
|
@ -1003,6 +1003,7 @@ DISSECTOR_SRC = \
|
|||
packet-sipfrag.c \
|
||||
packet-sita.c \
|
||||
packet-skinny.c \
|
||||
packet-skype.c \
|
||||
packet-slimp3.c \
|
||||
packet-sll.c \
|
||||
packet-slowprotocols.c \
|
||||
|
|
|
|||
|
|
@ -0,0 +1,352 @@
|
|||
/* packet-skype.c
|
||||
* Routines for the disassembly of Skype
|
||||
*
|
||||
* $Id$
|
||||
*
|
||||
* Copyright 2009 Joerg Mayer (see AUTHORS file)
|
||||
*
|
||||
* Wireshark - Network traffic analyzer
|
||||
* By Gerald Combs <gerald@wireshark.org>
|
||||
* Copyright 1998 Gerald Combs
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* as published by the Free Software Foundation; either version 2
|
||||
* of the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
*/
|
||||
|
||||
/*
|
||||
* https://github.com/matthiasbock/OpenSkype/wiki/Skype's-UDP-Format
|
||||
|
||||
TODO:
|
||||
- Authentication
|
||||
- TCP
|
||||
- Conversation stuff (to obtain external IPs for decryption)
|
||||
- Decryption (with given keys)
|
||||
- CRC check
|
||||
- Heuristics to reliably detect Skype traffic - most likely impossible
|
||||
to implement in Wireshark (see http://en.wikipedia.org/wiki/Skype)
|
||||
- Improve tests
|
||||
*/
|
||||
|
||||
#ifdef HAVE_CONFIG_H
|
||||
# include "config.h"
|
||||
#endif
|
||||
|
||||
#include <glib.h>
|
||||
#include <epan/packet.h>
|
||||
|
||||
/* protocol handles */
|
||||
static int proto_skype = -1;
|
||||
|
||||
/* ett handles */
|
||||
static int ett_skype = -1;
|
||||
|
||||
#define SKYPE_SOM_TYPE_MASK 0x00000F
|
||||
#define SKYPE_SOM_ID_MASK 0xFFFFF0
|
||||
|
||||
/* hf elements */
|
||||
/* Start of Message */
|
||||
static int hf_skype_som_id = -1;
|
||||
static int hf_skype_som_type = -1;
|
||||
/* Message body */
|
||||
/* Payload */
|
||||
static int hf_skype_payload_iv = -1;
|
||||
static int hf_skype_payload_crc = -1;
|
||||
static int hf_skype_payload_enc_data = -1;
|
||||
/* Resend */
|
||||
static int hf_skype_ffr_num = -1;
|
||||
static int hf_skype_ffr_unk1 = -1;
|
||||
static int hf_skype_ffr_iv = -1;
|
||||
static int hf_skype_ffr_crc = -1;
|
||||
static int hf_skype_ffr_enc_data = -1;
|
||||
/* Nat info */
|
||||
static int hf_skype_natinfo_srcip = -1;
|
||||
static int hf_skype_natinfo_unk1 = -1;
|
||||
/* Nat request */
|
||||
static int hf_skype_natrequest_srcip = -1;
|
||||
static int hf_skype_natrequest_unk1 = -1;
|
||||
/* Audio */
|
||||
static int hf_skype_audio_unk1 = -1;
|
||||
/* Unknown */
|
||||
static int hf_skype_unknown_f_unk1 = -1;
|
||||
|
||||
|
||||
#define PROTO_SHORT_NAME "SKYPE"
|
||||
#define PROTO_LONG_NAME "SKYPE"
|
||||
|
||||
#define PORT_SKYPE_UDP 0
|
||||
#if 0
|
||||
#define PORT_SKYPE_TCP 0
|
||||
#endif
|
||||
|
||||
typedef enum {
|
||||
SKYPE_TYPE_PAYLOAD = 2,
|
||||
SKYPE_TYPE_FFR = 3,
|
||||
SKYPE_TYPE_NAT_INFO = 5,
|
||||
SKYPE_TYPE_NAT_REPEAT = 7,
|
||||
SKYPE_TYPE_AUDIO = 0xd,
|
||||
SKYPE_TYPE_UNKNOWN = 0xf,
|
||||
} skype_type_t;
|
||||
|
||||
|
||||
static const value_string skype_type_vals[] = {
|
||||
{ SKYPE_TYPE_PAYLOAD, "Payload" },
|
||||
{ SKYPE_TYPE_FFR, "Fragment/Forward/Resend" },
|
||||
{ SKYPE_TYPE_NAT_INFO , "NAT info" },
|
||||
{ SKYPE_TYPE_NAT_REPEAT,"NAT repeat" },
|
||||
{ SKYPE_TYPE_AUDIO, "Audio" },
|
||||
{ SKYPE_TYPE_UNKNOWN , "Unknown" },
|
||||
|
||||
{ 0, NULL }
|
||||
};
|
||||
|
||||
static int
|
||||
dissect_skype(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
||||
{
|
||||
proto_item *ti;
|
||||
proto_tree *skype_tree = NULL;
|
||||
guint32 offset = 0;
|
||||
guint32 packet_length;
|
||||
guint8 packet_type;
|
||||
|
||||
packet_type = tvb_get_guint8(tvb, 2) & SKYPE_SOM_TYPE_MASK;
|
||||
|
||||
packet_length = tvb_length(tvb);
|
||||
|
||||
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
||||
col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_SHORT_NAME);
|
||||
if (check_col(pinfo->cinfo, COL_INFO))
|
||||
col_add_str(pinfo->cinfo, COL_INFO, val_to_str(packet_type,
|
||||
skype_type_vals, "Type 0x%02x"));
|
||||
|
||||
if (tree) {
|
||||
/* Start of message dissection */
|
||||
ti = proto_tree_add_item(tree, proto_skype, tvb, offset, -1,
|
||||
ENC_NA);
|
||||
skype_tree = proto_item_add_subtree(ti, ett_skype);
|
||||
|
||||
proto_tree_add_item(skype_tree, hf_skype_som_id, tvb, offset, 3,
|
||||
ENC_BIG_ENDIAN);
|
||||
proto_tree_add_item(skype_tree, hf_skype_som_type, tvb, offset, 3,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 3;
|
||||
|
||||
/* Body dissection */
|
||||
switch (packet_type) {
|
||||
|
||||
case SKYPE_TYPE_PAYLOAD:
|
||||
proto_tree_add_item(skype_tree, hf_skype_payload_iv, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_payload_crc, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_payload_enc_data, tvb, offset, -1,
|
||||
ENC_NA);
|
||||
offset = packet_length;
|
||||
break;
|
||||
case SKYPE_TYPE_FFR:
|
||||
proto_tree_add_item(skype_tree, hf_skype_ffr_num, tvb, offset, 1,
|
||||
ENC_NA);
|
||||
offset += 1;
|
||||
proto_tree_add_item(skype_tree, hf_skype_ffr_unk1, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_ffr_iv, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_ffr_crc, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_ffr_enc_data, tvb, offset, -1,
|
||||
ENC_NA);
|
||||
offset = packet_length;
|
||||
break;
|
||||
case SKYPE_TYPE_NAT_INFO:
|
||||
proto_tree_add_item(skype_tree, hf_skype_natinfo_srcip, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_natinfo_unk1, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
break;
|
||||
case SKYPE_TYPE_NAT_REPEAT:
|
||||
proto_tree_add_item(skype_tree, hf_skype_natrequest_srcip, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
proto_tree_add_item(skype_tree, hf_skype_natrequest_unk1, tvb, offset, 4,
|
||||
ENC_BIG_ENDIAN);
|
||||
offset += 4;
|
||||
break;
|
||||
case SKYPE_TYPE_AUDIO:
|
||||
proto_tree_add_item(skype_tree, hf_skype_audio_unk1, tvb, offset, -1,
|
||||
ENC_NA);
|
||||
offset = packet_length;
|
||||
break;
|
||||
case SKYPE_TYPE_UNKNOWN:
|
||||
proto_tree_add_item(skype_tree, hf_skype_unknown_f_unk1, tvb, offset, -1,
|
||||
ENC_NA);
|
||||
offset = packet_length;
|
||||
break;
|
||||
default:
|
||||
/* Should not happen: Unkown types filtered in test_skype */
|
||||
break;
|
||||
}
|
||||
}
|
||||
return offset;
|
||||
}
|
||||
|
||||
static gboolean
|
||||
test_skype(tvbuff_t *tvb)
|
||||
{
|
||||
/* Minimum of 3 bytes, check for valid message type */
|
||||
guint length = tvb_length(tvb);
|
||||
guint8 type = tvb_get_guint8(tvb, 2) & 0xF;
|
||||
if ( length >= 3 &&
|
||||
( type == 2 ||
|
||||
/* FIXME: Extend this by minimum length per message type */
|
||||
type == 3 ||
|
||||
type == 5 ||
|
||||
type == 7 ||
|
||||
type == 0xd ||
|
||||
type == 0xf
|
||||
)
|
||||
) {
|
||||
return TRUE;
|
||||
}
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
#if 0
|
||||
static gboolean
|
||||
dissect_skype_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
||||
{
|
||||
if ( !test_skype(tvb) ) {
|
||||
return FALSE;
|
||||
}
|
||||
dissect_skype(tvb, pinfo, tree);
|
||||
return TRUE;
|
||||
}
|
||||
#endif
|
||||
|
||||
static int
|
||||
dissect_skype_static(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
||||
{
|
||||
if ( !test_skype(tvb) ) {
|
||||
return 0;
|
||||
}
|
||||
return dissect_skype(tvb, pinfo, tree);
|
||||
}
|
||||
|
||||
void
|
||||
proto_register_skype(void)
|
||||
{
|
||||
static hf_register_info hf[] = {
|
||||
|
||||
/* Start of message fields */
|
||||
{ &hf_skype_som_id,
|
||||
{ "ID", "skype.som.id", FT_UINT24, BASE_HEX, NULL,
|
||||
SKYPE_SOM_ID_MASK, "Message ID", HFILL }},
|
||||
|
||||
{ &hf_skype_som_type,
|
||||
{ "Type", "skype.som.type", FT_UINT8, BASE_HEX, VALS(skype_type_vals),
|
||||
SKYPE_SOM_TYPE_MASK, "Message type", HFILL }},
|
||||
|
||||
/* Message body */
|
||||
|
||||
/* Payload */
|
||||
{ &hf_skype_payload_iv,
|
||||
{ "IV", "skype.payload.iv", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_payload_crc,
|
||||
{ "CRC", "skype.payload.crc", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_payload_enc_data,
|
||||
{ "Enc Data", "skype.payload.encdata", FT_BYTES, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
/* Resend */
|
||||
{ &hf_skype_ffr_num,
|
||||
{ "Num", "skype.ffr.num", FT_UINT8, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_ffr_unk1,
|
||||
{ "Unk1", "skype.ffr.unk1", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_ffr_iv,
|
||||
{ "IV", "skype.ffr.iv", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_ffr_crc,
|
||||
{ "CRC", "skype.ffr.crc", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_ffr_enc_data,
|
||||
{ "Enc Data", "skype.ffr.encdata", FT_BYTES, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
/* Nat info */
|
||||
{ &hf_skype_natinfo_srcip,
|
||||
{ "Src IP", "skype.natinfo.srcip", FT_IPv4, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_natinfo_unk1,
|
||||
{ "Unknown1", "skype.natinfo.unk1", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
/* Nat request */
|
||||
{ &hf_skype_natrequest_srcip,
|
||||
{ "Src IP", "skype.natrequest.srcip", FT_IPv4, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
{ &hf_skype_natrequest_unk1,
|
||||
{ "Unknown1", "skype.natrequest.unk1", FT_UINT32, BASE_HEX, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
/* Audio */
|
||||
{ &hf_skype_audio_unk1,
|
||||
{ "Unknown1", "skype.audio.unk1", FT_BYTES, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
/* Unknown */
|
||||
{ &hf_skype_unknown_f_unk1,
|
||||
{ "Unknown1", "skype.unknown_f.unk1", FT_BYTES, BASE_NONE, NULL,
|
||||
0x0, NULL, HFILL }},
|
||||
|
||||
};
|
||||
static gint *ett[] = {
|
||||
&ett_skype,
|
||||
};
|
||||
|
||||
proto_skype = proto_register_protocol(PROTO_LONG_NAME, PROTO_SHORT_NAME, "skype");
|
||||
proto_register_field_array(proto_skype, hf, array_length(hf));
|
||||
proto_register_subtree_array(ett, array_length(ett));
|
||||
}
|
||||
|
||||
void
|
||||
proto_reg_handoff_skype(void)
|
||||
{
|
||||
dissector_handle_t skype_handle;
|
||||
|
||||
skype_handle = new_create_dissector_handle(dissect_skype_static, proto_skype);
|
||||
dissector_add_uint("udp.port", PORT_SKYPE_UDP, skype_handle);
|
||||
#if 0
|
||||
dissector_add_uint("tcp.port", PORT_SKYPE_TCP, skype_handle);
|
||||
heur_dissector_add("udp", dissect_skype_heur, proto_skype);
|
||||
#endif
|
||||
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue