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wireshark/packet-eapol.c
Guy Harris 83b201486f Dissect the payload of EAPOL Key messages. 
Put in a comment noting that the payload of EAPOL Encapsulated ASF Alert
messages should perhaps be dissected as SNMP Trap messages.

Put the type of the message into the Info column.

svn path=/trunk/; revision=4789
2002-02-22 23:05:16 +00:00

245 lines
7.7 KiB
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/* packet-eapol.c
* Routines for EAPOL 802.1X authentication header disassembly
* (From IEEE Draft P802.1X/D11; is there a later draft, or a
* final standard? If so, check it.)
*
* $Id: packet-eapol.c,v 1.8 2002/02/22 23:05:16 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#include <glib.h>
#include <epan/packet.h>
#include "packet-ieee8023.h"
#include "packet-ipx.h"
#include "packet-llc.h"
#include "etypes.h"
static int proto_eapol = -1;
static int hf_eapol_version = -1;
static int hf_eapol_type = -1;
static int hf_eapol_len = -1;
static int hf_eapol_keydes_type = -1;
static int hf_eapol_keydes_keylen = -1;
static int hf_eapol_keydes_replay_counter = -1;
static int hf_eapol_keydes_key_iv = -1;
static int hf_eapol_keydes_key_index_keytype = -1;
static int hf_eapol_keydes_key_index_indexnum = -1;
static int hf_eapol_keydes_key_signature = -1;
static int hf_eapol_keydes_key = -1;
static gint ett_eapol = -1;
static gint ett_eapol_key_index = -1;
static dissector_handle_t eap_handle;
static dissector_handle_t data_handle;
#define EAPOL_HDR_LEN 4
#define EAP_PACKET 0
#define EAPOL_START 1
#define EAPOL_LOGOFF 2
#define EAPOL_KEY 3
#define EAPOL_ENCAP_ASF_ALERT 4
static const value_string eapol_type_vals[] = {
{ EAP_PACKET, "EAP Packet" },
{ EAPOL_START, "Start" },
{ EAPOL_LOGOFF, "Logoff" },
{ EAPOL_KEY, "Key" },
{ EAPOL_ENCAP_ASF_ALERT, "Encapsulated ASF Alert" },
{ 0, NULL }
};
static const value_string eapol_keydes_type_vals[] = {
{ 1, "RC4 Descriptor" },
{ 0, NULL }
};
static const true_false_string keytype_tfs =
{ "Unicast", "Broadcast" };
static void
dissect_eapol(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset = 0;
guint8 eapol_ver;
guint8 eapol_type;
guint16 eapol_len;
guint len;
guint16 eapol_key_len;
guint8 key_index;
proto_tree *ti = NULL;
proto_tree *eapol_tree = NULL;
proto_tree *key_index_tree;
tvbuff_t *next_tvb;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "EAPOL");
if (check_col(pinfo->cinfo, COL_INFO))
col_clear(pinfo->cinfo, COL_INFO);
if (tree) {
ti = proto_tree_add_item(tree, proto_eapol, tvb, 0, -1, FALSE);
eapol_tree = proto_item_add_subtree(ti, ett_eapol);
proto_tree_add_item(eapol_tree, hf_eapol_version, tvb, offset, 1, FALSE);
}
offset++;
eapol_type = tvb_get_guint8(tvb, offset);
if (tree)
proto_tree_add_uint(eapol_tree, hf_eapol_type, tvb, offset, 1, eapol_type);
if (check_col(pinfo->cinfo, COL_INFO))
col_add_str(pinfo->cinfo, COL_INFO,
val_to_str(eapol_type, eapol_type_vals, "Unknown type (0x%02X)"));
offset++;
eapol_len = tvb_get_ntohs(tvb, offset);
len = EAPOL_HDR_LEN + eapol_len;
set_actual_length(tvb, len);
if (tree) {
proto_item_set_len(ti, len);
proto_tree_add_uint(eapol_tree, hf_eapol_len, tvb, offset, 2, eapol_len);
}
offset += 2;
switch (eapol_type) {
case EAP_PACKET:
next_tvb = tvb_new_subset(tvb, offset, -1, -1);
call_dissector(eap_handle, next_tvb, pinfo, eapol_tree);
break;
case EAPOL_KEY:
if (tree) {
proto_tree_add_item(eapol_tree, hf_eapol_keydes_type, tvb, offset, 1, FALSE);
offset += 1;
eapol_key_len = tvb_get_ntohs(tvb, offset);
proto_tree_add_uint(eapol_tree, hf_eapol_keydes_keylen, tvb, offset, 2, eapol_key_len);
offset += 2;
proto_tree_add_item(eapol_tree, hf_eapol_keydes_replay_counter, tvb,
offset, 8, FALSE);
offset += 8;
proto_tree_add_item(eapol_tree, hf_eapol_keydes_key_iv, tvb,
offset, 16, FALSE);
offset += 16;
key_index = tvb_get_guint8(tvb, offset);
ti = proto_tree_add_text(eapol_tree, tvb, offset, 1,
"Key Index: %s, index %u",
(key_index & 0x80) ? "unicast" : "broadcast",
key_index & 0x7F);
key_index_tree = proto_item_add_subtree(ti, ett_eapol_key_index);
proto_tree_add_boolean(eapol_tree, hf_eapol_keydes_key_index_keytype,
tvb, offset, 1, key_index);
proto_tree_add_boolean(eapol_tree, hf_eapol_keydes_key_index_indexnum,
tvb, offset, 1, key_index);
offset += 1;
proto_tree_add_item(eapol_tree, hf_eapol_keydes_key_signature, tvb,
offset, 16, FALSE);
offset += 16;
if (eapol_key_len != 0)
proto_tree_add_item(eapol_tree, hf_eapol_keydes_key, tvb, offset,
eapol_key_len, FALSE);
}
break;
case EAPOL_ENCAP_ASF_ALERT: /* XXX - is this an SNMP trap? */
default:
next_tvb = tvb_new_subset(tvb, offset, -1, -1);
call_dissector(data_handle, next_tvb, pinfo, eapol_tree);
break;
}
}
void
proto_register_eapol(void)
{
static hf_register_info hf[] = {
{ &hf_eapol_version, {
"Version", "eapol.version", FT_UINT8, BASE_DEC,
NULL, 0x0, "", HFILL }},
{ &hf_eapol_type, {
"Type", "eapol.type", FT_UINT8, BASE_DEC,
VALS(eapol_type_vals), 0x0, "", HFILL }},
{ &hf_eapol_len, {
"Length", "eapol.len", FT_UINT16, BASE_DEC,
NULL, 0x0, "Length", HFILL }},
{ &hf_eapol_keydes_type, {
"Descriptor Type", "eapol.keydes.type", FT_UINT8, BASE_DEC,
VALS(eapol_keydes_type_vals), 0x0, "Key Descriptor Type", HFILL }},
{ &hf_eapol_keydes_keylen, {
"Key Length", "eapol.keydes.keylen", FT_UINT16, BASE_DEC,
NULL, 0x0, "Key Length", HFILL }},
{ &hf_eapol_keydes_replay_counter, {
"Replay Counter", "eapol.keydes.replay_counter", FT_UINT64, BASE_DEC,
NULL, 0x0, "Replay Counter", HFILL }},
{ &hf_eapol_keydes_key_iv, {
"Key IV", "eapol.keydes.key_iv", FT_BYTES, BASE_NONE,
NULL, 0x0, "Key Initialization Vector", HFILL }},
{ &hf_eapol_keydes_key_index_keytype, {
"Key Type", "eapol.keydes.index.keytype", FT_BOOLEAN, 8,
TFS(&keytype_tfs), 0x80, "Key Type (unicast/broadcast)", HFILL }},
{ &hf_eapol_keydes_key_index_indexnum, {
"Index Number", "eapol.keydes.index.indexnum", FT_UINT8, BASE_DEC,
NULL, 0x7F, "Key Index number", HFILL }},
{ &hf_eapol_keydes_key_signature, {
"Key Signature", "eapol.keydes.key_signature", FT_BYTES, BASE_NONE,
NULL, 0x0, "Key Signature", HFILL }},
{ &hf_eapol_keydes_key, {
"Key", "eapol.keydes.key", FT_BYTES, BASE_NONE,
NULL, 0x0, "Key", HFILL }},
};
static gint *ett[] = {
&ett_eapol,
&ett_eapol_key_index
};
proto_eapol = proto_register_protocol("802.1x Authentication", "EAPOL", "eapol");
proto_register_field_array(proto_eapol, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_eapol(void)
{
dissector_handle_t eapol_handle;
/*
* Get handles for the EAP and raw data dissectors.
*/
eap_handle = find_dissector("eap");
data_handle = find_dissector("data");
eapol_handle = create_dissector_handle(dissect_eapol, proto_eapol);
dissector_add("ethertype", ETHERTYPE_EAPOL, eapol_handle);
}
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