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wireshark/epan/dissectors/packet-zrtp.c

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/* packet-zrtp.c
* Routines for zrtp packet dissection
* IETF draft draft-zimmermann-avt-zrtp-22
* Copyright 2007, Sagar Pai <sagar@gmail.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-pop.c
*
* 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.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/crc32-tvb.h>
#include <wsutil/crc32.h>
#include "packet-rtp.h"
#include "packet-rtcp.h"
void proto_reg_handoff_zrtp(void);
void proto_register_zrtp(void);
/*
RTP header
*/
static int proto_zrtp = -1;
static int hf_zrtp_rtpversion = -1;
static int hf_zrtp_rtppadding = -1;
static int hf_zrtp_rtpextension = -1;
/* static int hf_zrtp_id = -1; */
static int hf_zrtp_sequence = -1;
static int hf_zrtp_cookie = -1;
static int hf_zrtp_source_id = -1;
/*
ZRTP header
*/
static int hf_zrtp_signature = -1;
static int hf_zrtp_msg_length = -1;
static int hf_zrtp_msg_type = -1;
static int hf_zrtp_msg_version = -1;
/*
Hello Data
*/
static int hf_zrtp_msg_client_id = -1;
static int hf_zrtp_msg_zid = -1;
static int hf_zrtp_msg_sigcap = -1;
static int hf_zrtp_msg_mitm = -1;
static int hf_zrtp_msg_passive = -1;
static int hf_zrtp_msg_hash_count = -1;
static int hf_zrtp_msg_cipher_count = -1;
static int hf_zrtp_msg_authtag_count = -1;
static int hf_zrtp_msg_key_count = -1;
static int hf_zrtp_msg_sas_count = -1;
static int hf_zrtp_msg_hash = -1;
static int hf_zrtp_msg_cipher = -1;
static int hf_zrtp_msg_at = -1;
static int hf_zrtp_msg_keya = -1;
static int hf_zrtp_msg_sas = -1;
static int hf_zrtp_msg_hash_image = -1;
/*
Commit Data
*/
static int hf_zrtp_msg_hvi = -1;
static int hf_zrtp_msg_nonce = -1;
static int hf_zrtp_msg_key_id = -1;
/*
DHParts Data
*/
static int hf_zrtp_msg_rs1ID = -1;
static int hf_zrtp_msg_rs2ID = -1;
static int hf_zrtp_msg_auxs = -1;
static int hf_zrtp_msg_pbxs = -1;
/*
Confirm Data
*/
static int hf_zrtp_msg_hmac = -1;
static int hf_zrtp_msg_cfb = -1;
/*
Error Data
*/
static int hf_zrtp_msg_error = -1;
/*
Ping Data
*/
static int hf_zrtp_msg_ping_version = -1;
static int hf_zrtp_msg_ping_endpointhash = -1;
static int hf_zrtp_msg_pingack_endpointhash = -1;
static int hf_zrtp_msg_ping_ssrc = -1;
/*
Checksum Data
*/
static int hf_zrtp_checksum = -1;
static int hf_zrtp_checksum_status = -1;
/*
Sub-Tree
*/
static gint ett_zrtp = -1;
static gint ett_zrtp_msg = -1;
static gint ett_zrtp_msg_data = -1;
static gint ett_zrtp_msg_hc = -1;
static gint ett_zrtp_msg_kc = -1;
static gint ett_zrtp_msg_ac = -1;
static gint ett_zrtp_msg_cc = -1;
static gint ett_zrtp_msg_sc = -1;
static gint ett_zrtp_checksum = -1;
static expert_field ei_zrtp_checksum = EI_INIT;
static dissector_handle_t zrtp_handle;
/*
Definitions
*/
#define ZRTP_ERR_10 0x10
#define ZRTP_ERR_20 0x20
#define ZRTP_ERR_30 0x30
#define ZRTP_ERR_40 0x40
#define ZRTP_ERR_51 0x51
#define ZRTP_ERR_52 0x52
#define ZRTP_ERR_53 0x53
#define ZRTP_ERR_54 0x54
#define ZRTP_ERR_55 0x55
#define ZRTP_ERR_56 0x56
#define ZRTP_ERR_61 0x61
#define ZRTP_ERR_62 0x62
#define ZRTP_ERR_63 0x63
#define ZRTP_ERR_70 0x70
#define ZRTP_ERR_80 0x80
#define ZRTP_ERR_90 0x90
#define ZRTP_ERR_91 0x91
#define ZRTP_ERR_A0 0xA0
#define ZRTP_ERR_B0 0xB0
#define ZRTP_ERR_100 0x100
/*
Text for Display
*/
typedef struct _value_zrtp_versions {
const gchar *version;
} value_zrtp_versions;
typedef struct _value_string_keyval {
const gchar *key;
const gchar *val;
} value_string_keyval;
const value_zrtp_versions valid_zrtp_versions[] =
{
{"1.1x"},
{"1.0x"},
{"0.95"},
{"0.90"},
{"0.85"},
{NULL}
};
const value_string_keyval zrtp_hash_type_vals[] =
{
{ "S256", "SHA-256 Hash"},
{ "S384", "SHA-384 Hash"},
{ "N256", "SHA-3 256-bit hash"},
{ "N384", "SHA-3 384 bit hash"},
{ NULL, NULL }
};
const value_string_keyval zrtp_cipher_type_vals[] =
{
{ "AES1", "AES-CM with 128 bit keys"},
{ "AES2", "AES-CM with 192 bit keys"},
{ "AES3", "AES-CM with 256 bit keys"},
{ "2FS1", "TwoFish with 128 bit keys"},
{ "2FS2", "TwoFish with 192 bit keys"},
{ "2FS3", "TwoFish with 256 bit keys"},
{ "CAM1", "Camellia with 128 bit keys"},
{ "CAM2", "Camellia with 192 bit keys"},
{ "CAM3", "Camellia with 256 bit keys"},
{ NULL, NULL }
};
const value_string_keyval zrtp_auth_tag_vals[] =
{
{ "HS32", "HMAC-SHA1 32 bit authentication tag"},
{ "HS80", "HMAC-SHA1 80 bit authentication tag"},
{ "SK32", "Skein-512-MAC 32 bit authentication tag"},
{ "SK64", "Skein-512-MAC 64 bit authentication tag"},
{ NULL, NULL }
};
const value_string_keyval zrtp_sas_type_vals[] =
{
{ "B32 ", "Short authentication string using base 32"},
{ "B256", "Short authentication string using base 256"},
{ NULL, NULL }
};
const value_string_keyval zrtp_key_agreement_vals[] =
{
{ "DH2k", "DH mode with p=2048 bit prime"},
{ "DH3k", "DH mode with p=3072 bit prime"},
{ "DH4k", "DH mode with p=4096 bit prime"},
{ "Prsh", "Preshared non-DH mode using shared secret"},
{ "EC25", "Elliptic Curve DH-256"},
{ "EC38", "Elliptic Curve DH-384"},
{ "EC52", "Elliptic Curve DH-521"},
{ "Mult", "Multistream mode"},
{ NULL, NULL }
};
const value_string zrtp_error_vals[] =
{
{ ZRTP_ERR_10, "Malformed Packet (CRC OK but wrong structure)"},
{ ZRTP_ERR_20, "Critical Software Error"},
{ ZRTP_ERR_30, "Unsupported ZRTP version"},
{ ZRTP_ERR_40, "Hello Components mismatch"},
{ ZRTP_ERR_51, "Hash type unsupported"},
{ ZRTP_ERR_52, "Cipher type not supported"},
{ ZRTP_ERR_53, "Public key exchange not supported"},
{ ZRTP_ERR_54, "SRTP auth. tag not supported"},
{ ZRTP_ERR_55, "SAS scheme not supported"},
{ ZRTP_ERR_56, "No shared secret available, DH mode required"},
{ ZRTP_ERR_61, "DH Error: bad pv for initiator/responder value is (1,0,p-1)"},
{ ZRTP_ERR_62, "DH Error: bad hash commitment (hvi != hashed data)"},
{ ZRTP_ERR_63, "Received relayed SAS from untrusted MiTM"},
{ ZRTP_ERR_70, "Auth. Error Bad Confirm Packet HMAC"},
{ ZRTP_ERR_80, "Nonce is reused"},
{ ZRTP_ERR_90, "Equal ZID's in Hello"},
{ ZRTP_ERR_91, "SSRC collision"},
{ ZRTP_ERR_A0, "Service unavailable"},
{ ZRTP_ERR_B0, "Protocol timeout error"},
{ ZRTP_ERR_100, "GoClear packet received, but not allowed"},
{ 0, NULL}
};
static void
dissect_Hello(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_ErrorACK(packet_info *pinfo);
static void
dissect_Commit(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_ClearACK( packet_info *pinfo);
static void
dissect_Conf2ACK(packet_info *pinfo);
static void
dissect_HelloACK( packet_info *pinfo);
static void
dissect_GoClear(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_Error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_Confirm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree, int part);
static void
dissect_DHPart(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree, int part);
static void
dissect_SASrelay(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_RelayACK(packet_info *pinfo);
static void
dissect_Ping(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static void
dissect_PingACK(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree);
static const gchar *
key_to_val(const gchar *key, int keylen, const value_string_keyval *kv, const gchar *fmt) {
int i = 0;
while (kv[i].key) {
if (!strncmp(kv[i].key, key, keylen)) {
return(kv[i].val);
}
i++;
}
return wmem_strdup_printf(wmem_packet_scope(), fmt, key);
}
static const gchar *
check_valid_version(const gchar *version) {
int i = 0;
int match_size = (version[0] == '0') ? 4 : 3;
while (valid_zrtp_versions[i].version) {
if (!strncmp(valid_zrtp_versions[i].version, version, match_size)) {
return(valid_zrtp_versions[i].version);
}
i++;
}
return NULL;
}
static int
dissect_zrtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *zrtp_tree;
proto_tree *zrtp_msg_tree;
proto_tree *zrtp_msg_data_tree;
proto_item *ti;
int linelen;
int checksum_offset;
unsigned char message_type[9];
unsigned int prime_offset = 0;
unsigned int msg_offset = 12;
guint32 calc_crc;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ZRTP");
col_set_str(pinfo->cinfo, COL_INFO, "Unknown ZRTP Packet");
ti = proto_tree_add_protocol_format(tree, proto_zrtp, tvb, 0, -1, "ZRTP protocol");
zrtp_tree = proto_item_add_subtree(ti, ett_zrtp);
proto_tree_add_item(zrtp_tree, hf_zrtp_rtpversion, tvb, prime_offset+0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_rtppadding, tvb, prime_offset+0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_rtpextension, tvb, prime_offset+0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_sequence, tvb, prime_offset+2, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_cookie, tvb, prime_offset+4, 4, ENC_ASCII|ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_source_id, tvb, prime_offset+8, 4, ENC_BIG_ENDIAN);
linelen = tvb_reported_length_remaining(tvb, msg_offset);
checksum_offset = linelen-4;
ti = proto_tree_add_protocol_format(zrtp_tree, proto_zrtp, tvb, msg_offset, linelen-4, "Message");
zrtp_msg_tree = proto_item_add_subtree(ti, ett_zrtp_msg);
proto_tree_add_item(zrtp_msg_tree, hf_zrtp_signature, tvb, msg_offset+0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_msg_tree, hf_zrtp_msg_length, tvb, msg_offset+2, 2, ENC_BIG_ENDIAN);
tvb_memcpy(tvb, (void *)message_type, msg_offset+4, 8);
message_type[8] = '\0';
proto_tree_add_item(zrtp_msg_tree, hf_zrtp_msg_type, tvb, msg_offset+4, 8, ENC_ASCII|ENC_NA);
linelen = tvb_reported_length_remaining(tvb, msg_offset+12);
if (!strncmp(message_type, "Hello ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Hello(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "HelloACK", 8)) {
dissect_HelloACK(pinfo);
} else if (!strncmp(message_type, "Commit ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Commit(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "DHPart1 ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_DHPart(tvb, pinfo, zrtp_msg_data_tree, 1);
} else if (!strncmp(message_type, "DHPart2 ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_DHPart(tvb, pinfo, zrtp_msg_data_tree, 2);
} else if (!strncmp(message_type, "Confirm1", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Confirm(tvb, pinfo, zrtp_msg_data_tree, 1);
} else if (!strncmp(message_type, "Confirm2", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Confirm(tvb, pinfo, zrtp_msg_data_tree, 2);
} else if (!strncmp(message_type, "Conf2ACK", 8)) {
dissect_Conf2ACK(pinfo);
} else if (!strncmp(message_type, "Error ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Error(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "ErrorACK", 8)) {
dissect_ErrorACK(pinfo);
} else if (!strncmp(message_type, "GoClear ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_GoClear(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "ClearACK", 8)) {
dissect_ClearACK(pinfo);
} else if (!strncmp(message_type, "SASrelay", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_SASrelay(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "RelayACK", 8)) {
dissect_RelayACK(pinfo);
} else if (!strncmp(message_type, "Ping ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_Ping(tvb, pinfo, zrtp_msg_data_tree);
} else if (!strncmp(message_type, "PingACK ", 8)) {
ti = proto_tree_add_protocol_format(zrtp_msg_tree, proto_zrtp, tvb, msg_offset+12, linelen-4, "Data");
zrtp_msg_data_tree = proto_item_add_subtree(ti, ett_zrtp_msg_data);
dissect_PingACK(tvb, pinfo, zrtp_msg_data_tree);
}
calc_crc = ~crc32c_tvb_offset_calculate(tvb, 0, msg_offset+checksum_offset, CRC32C_PRELOAD);
proto_tree_add_checksum(zrtp_tree, tvb, msg_offset+checksum_offset, hf_zrtp_checksum, hf_zrtp_checksum_status, &ei_zrtp_checksum, pinfo, calc_crc,
ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
return tvb_captured_length(tvb);
}
static void
dissect_ErrorACK(packet_info *pinfo) {
col_set_str(pinfo->cinfo, COL_INFO, "ErrorACK Packet");
}
static void
dissect_ClearACK(packet_info *pinfo) {
col_set_str(pinfo->cinfo, COL_INFO, "ClearACK Packet");
}
static void
dissect_RelayACK(packet_info *pinfo) {
col_set_str(pinfo->cinfo, COL_INFO, "RelayACK Packet");
}
static void
dissect_Conf2ACK(packet_info *pinfo) {
/* Signals start of SRT(C)P streams */
struct srtp_info *dummy_srtp_info = wmem_new0(wmem_file_scope(), struct srtp_info);
dummy_srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
dummy_srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
dummy_srtp_info->mki_len = 0;
dummy_srtp_info->auth_tag_len = 4;
srtp_add_address(pinfo, PT_UDP, &pinfo->net_src, pinfo->srcport, pinfo->destport,
"ZRTP", pinfo->num, RTP_MEDIA_AUDIO, NULL, dummy_srtp_info);
srtp_add_address(pinfo, PT_UDP, &pinfo->net_dst, pinfo->destport, pinfo->srcport,
"ZRTP", pinfo->num, RTP_MEDIA_AUDIO, NULL, dummy_srtp_info);
srtcp_add_address(pinfo, &pinfo->net_src, pinfo->srcport+1, pinfo->destport+1,
"ZRTP", pinfo->num, dummy_srtp_info);
srtcp_add_address(pinfo, &pinfo->net_dst, pinfo->destport+1, pinfo->srcport+1,
"ZRTP", pinfo->num, dummy_srtp_info);
col_set_str(pinfo->cinfo, COL_INFO, "Conf2ACK Packet");
}
static void
dissect_HelloACK(packet_info *pinfo) {
col_set_str(pinfo->cinfo, COL_INFO, "HelloACK Packet");
}
static void
dissect_Ping(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int data_offset = 24;
col_set_str(pinfo->cinfo, COL_INFO, "Ping Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_ping_version, tvb, data_offset, 4, ENC_ASCII|ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_ping_endpointhash, tvb, data_offset+4, 8, ENC_BIG_ENDIAN);
}
static void
dissect_PingACK(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int data_offset = 24;
col_set_str(pinfo->cinfo, COL_INFO, "PingACK Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_ping_version, tvb, data_offset, 4, ENC_ASCII|ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_pingack_endpointhash, tvb, data_offset+4, 8, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_ping_endpointhash, tvb, data_offset+12, 8, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_ping_ssrc, tvb, data_offset+20, 4, ENC_BIG_ENDIAN);
}
static void
dissect_GoClear(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int data_offset = 24;
col_set_str(pinfo->cinfo, COL_INFO, "GoClear Packet");
/* Now we should clear the SRT(C)P session... */
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, data_offset+0, 8, ENC_NA);
}
static void
dissect_Error(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int data_offset = 24;
col_set_str(pinfo->cinfo, COL_INFO, "Error Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_error, tvb, data_offset, 4, ENC_BIG_ENDIAN);
}
static void
dissect_Confirm(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree, int part) {
unsigned int data_offset = 24;
int linelen;
col_add_fstr(pinfo->cinfo, COL_INFO, (part == 1) ? "Confirm1 Packet" : "Confirm2 Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, data_offset+0, 8, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_cfb, tvb, data_offset+8, 16, ENC_NA);
linelen = tvb_reported_length_remaining(tvb, data_offset+24);
proto_tree_add_protocol_format(zrtp_tree, proto_zrtp, tvb, data_offset+24, linelen-4, "Encrypted Data");
}
static void
dissect_SASrelay(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int data_offset = 24;
int linelen;
col_set_str(pinfo->cinfo, COL_INFO, "SASrelay Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, data_offset+0, 8, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_cfb, tvb, data_offset+8, 16, ENC_NA);
linelen = tvb_reported_length_remaining(tvb, data_offset+24);
proto_tree_add_protocol_format(zrtp_tree, proto_zrtp, tvb, data_offset+24, linelen-4, "Encrypted Data");
}
static void
dissect_DHPart(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree, int part) {
unsigned int msg_offset = 12;
unsigned int data_offset = 56;
int linelen, pvr_len;
col_add_fstr(pinfo->cinfo, COL_INFO, (part == 1) ? "DHPart1 Packet" : "DHPart2 Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hash_image, tvb, msg_offset+12, 32, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_rs1ID, tvb, data_offset+0, 8, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_rs2ID, tvb, data_offset+8, 8, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_auxs, tvb, data_offset+16, 8, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_pbxs, tvb, data_offset+24, 8, ENC_NA);
linelen = tvb_reported_length_remaining(tvb, data_offset+32);
pvr_len = linelen-8-4;
proto_tree_add_protocol_format(zrtp_tree, proto_zrtp, tvb, data_offset+32, pvr_len, (part==1) ? "pvr Data" : "pvi Data");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, data_offset+32+pvr_len, 8, ENC_NA);
}
static void
dissect_Commit(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
unsigned int msg_offset = 12;
unsigned int data_offset = 56;
unsigned char value[5];
int key_type = 0;
/*
0 - other type
1 - "Mult"
2 - "Prsh"
*/
unsigned int offset;
col_set_str(pinfo->cinfo, COL_INFO, "Commit Packet");
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hash_image, tvb, msg_offset+12, 32, ENC_NA);
/* ZID */
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_zid, tvb, data_offset+0, 12, ENC_NA);
tvb_memcpy(tvb, (void *)value, data_offset+12, 4);
value[4] = '\0';
proto_tree_add_string_format_value(zrtp_tree, hf_zrtp_msg_hash, tvb, data_offset+12, 4, value,
"%s", key_to_val(value, 4, zrtp_hash_type_vals, "Unknown hash type %s"));
tvb_memcpy(tvb, (void *)value, data_offset+16, 4);
value[4] = '\0';
proto_tree_add_string_format_value(zrtp_tree, hf_zrtp_msg_cipher, tvb, data_offset+16, 4, value, "%s",
key_to_val(value, 4, zrtp_cipher_type_vals, "Unknown cipher type %s"));
tvb_memcpy(tvb, (void *)value, data_offset+20, 4);
value[4] = '\0';
proto_tree_add_string_format(zrtp_tree, hf_zrtp_msg_at, tvb, data_offset+20, 4, value,
"Auth tag: %s", key_to_val(value, 4, zrtp_auth_tag_vals, "Unknown auth tag %s"));
tvb_memcpy(tvb, (void *)value, data_offset+24, 4);
value[4] = '\0';
proto_tree_add_string_format_value(zrtp_tree, hf_zrtp_msg_keya, tvb, data_offset+24, 4, value,
"%s", key_to_val(value, 4, zrtp_key_agreement_vals, "Unknown key agreement %s"));
if(!strncmp(value, "Mult", 4)) {
key_type = 1;
} else if (!strncmp(value, "Prsh", 4)) {
key_type = 2;
}
tvb_memcpy(tvb, (void *)value, data_offset+28, 4);
value[4] = '\0';
proto_tree_add_string_format(zrtp_tree, hf_zrtp_msg_sas, tvb, data_offset+28, 4, value,
"SAS type: %s", key_to_val(value, 4, zrtp_sas_type_vals, "Unknown SAS type %s"));
switch (key_type) {
case 1: /*
Mult
*/
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_nonce, tvb, data_offset+32, 16, ENC_NA);
offset = 48;
break;
case 2: /*
Prsh
*/
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_nonce, tvb, data_offset+32, 16, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_key_id, tvb, data_offset+48, 8, ENC_NA);
offset = 56;
break;
default: /*
other
*/
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hvi, tvb, data_offset+32, 32, ENC_NA);
offset = 64;
break;
}
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, data_offset+offset, 8, ENC_NA);
}
static void
dissect_Hello(tvbuff_t *tvb, packet_info *pinfo, proto_tree *zrtp_tree) {
proto_item *ti;
unsigned int msg_offset = 12;
unsigned int data_offset = 88;
guint8 val_b;
unsigned int i;
unsigned int run_offset;
unsigned int hc, cc, ac, kc, sc;
unsigned int vhc, vcc, vac, vkc, vsc;
unsigned char value[5];
unsigned char version_str[5];
proto_tree *tmp_tree;
col_set_str(pinfo->cinfo, COL_INFO, "Hello Packet");
tvb_memcpy(tvb, version_str, msg_offset+12, 4);
version_str[4] = '\0';
if (check_valid_version(version_str) == NULL) {
col_set_str(pinfo->cinfo, COL_INFO, "Unsupported version of ZRTP protocol");
}
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_version, tvb, msg_offset+12, 4, ENC_ASCII|ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_client_id, tvb, msg_offset+16, 16, ENC_ASCII|ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hash_image, tvb, msg_offset+32, 32, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_zid, tvb, msg_offset+64, 12, ENC_NA);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_sigcap, tvb, data_offset+0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_mitm, tvb, data_offset+0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_passive, tvb, data_offset+0, 1, ENC_BIG_ENDIAN);
val_b = tvb_get_guint8(tvb, data_offset+1);
hc = val_b & 0x0F;
vhc = hc;
val_b = tvb_get_guint8(tvb, data_offset+2);
cc = val_b & 0xF0;
ac = val_b & 0x0F;
vcc = cc >> 4;
vac = ac;
val_b = tvb_get_guint8(tvb, data_offset+3);
kc = val_b & 0xF0;
sc = val_b & 0x0F;
vkc = kc >> 4;
vsc = sc;
ti = proto_tree_add_uint_format(zrtp_tree, hf_zrtp_msg_hash_count, tvb, data_offset+1, 1, hc, "Hash type count = %d", vhc);
tmp_tree = proto_item_add_subtree(ti, ett_zrtp_msg_hc);
run_offset = data_offset+4;
for (i=0; i<vhc; i++) {
tvb_memcpy(tvb, (void *)value, run_offset, 4);
value[4] = '\0';
proto_tree_add_string_format(tmp_tree, hf_zrtp_msg_hash, tvb, run_offset, 4, value,
"Hash[%d]: %s", i, key_to_val(value, 4, zrtp_hash_type_vals, "Unknown hash type %s"));
run_offset += 4;
}
ti = proto_tree_add_uint_format(zrtp_tree, hf_zrtp_msg_cipher_count, tvb, data_offset+2, 1, cc, "Cipher type count = %d", vcc);
tmp_tree = proto_item_add_subtree(ti, ett_zrtp_msg_cc);
for (i=0; i<vcc; i++) {
tvb_memcpy(tvb, (void *)value, run_offset, 4);
value[4] = '\0';
proto_tree_add_string_format(tmp_tree, hf_zrtp_msg_cipher, tvb, run_offset, 4, value, "Cipher[%d]: %s", i,
key_to_val(value, 4, zrtp_cipher_type_vals, "Unknown cipher type %s"));
run_offset += 4;
}
ti = proto_tree_add_uint_format(zrtp_tree, hf_zrtp_msg_authtag_count, tvb, data_offset+2, 1, ac, "Auth tag count = %d", vac);
tmp_tree = proto_item_add_subtree(ti, ett_zrtp_msg_ac);
for (i=0; i<vac; i++) {
tvb_memcpy(tvb, (void *)value, run_offset, 4);
value[4] = '\0';
proto_tree_add_string_format(tmp_tree, hf_zrtp_msg_at, tvb, run_offset, 4, value,
"Auth tag[%d]: %s", i, key_to_val(value, 4, zrtp_auth_tag_vals, "Unknown auth tag %s"));
run_offset += 4;
}
ti = proto_tree_add_uint_format(zrtp_tree, hf_zrtp_msg_key_count, tvb, data_offset+3, 1, kc, "Key agreement type count = %d", vkc);
tmp_tree = proto_item_add_subtree(ti, ett_zrtp_msg_kc);
for (i=0; i<vkc; i++) {
tvb_memcpy(tvb, (void *)value, run_offset, 4);
value[4] = '\0';
proto_tree_add_string_format(tmp_tree, hf_zrtp_msg_keya, tvb, run_offset, 4, value,
"Key agreement[%d]: %s", i, key_to_val(value, 4, zrtp_key_agreement_vals, "Unknown key agreement %s"));
run_offset += 4;
}
ti = proto_tree_add_uint_format(zrtp_tree, hf_zrtp_msg_sas_count, tvb, data_offset+3, 1, sc, "SAS type count = %d", vsc);
tmp_tree = proto_item_add_subtree(ti, ett_zrtp_msg_sc);
for (i=0; i<vsc; i++) {
tvb_memcpy(tvb, (void *)value, run_offset, 4);
value[4] = '\0';
proto_tree_add_string_format(tmp_tree, hf_zrtp_msg_sas, tvb, run_offset, 4, value,
"SAS type[%d]: %s", i, key_to_val(value, 4, zrtp_sas_type_vals, "Unknown SAS type %s"));
run_offset += 4;
}
proto_tree_add_item(zrtp_tree, hf_zrtp_msg_hmac, tvb, run_offset, 8, ENC_NA);
}
void
proto_register_zrtp(void)
{
static hf_register_info hf[] = {
{&hf_zrtp_rtpversion,
{
"RTP Version", "zrtp.rtpversion",
FT_UINT8, BASE_DEC,
NULL, 0xC0,
NULL, HFILL
}
},
{&hf_zrtp_rtppadding,
{
"RTP padding", "zrtp.rtppadding",
FT_BOOLEAN, 8,
NULL, 0x20,
NULL, HFILL
}
},
{&hf_zrtp_rtpextension,
{
"RTP Extension", "zrtp.rtpextension",
FT_BOOLEAN, 8,
NULL, 0x10,
NULL, HFILL
}
},
#if 0
{&hf_zrtp_id,
{
"ID", "zrtp.id",
FT_UINT8, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
#endif
{&hf_zrtp_sequence,
{
"Sequence", "zrtp.sequence",
FT_UINT16, BASE_DEC,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_cookie,
{
"Magic Cookie", "zrtp.cookie",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_source_id,
{
"Source Identifier", "zrtp.source_id",
FT_UINT32, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
/*
Message Types
*/
{&hf_zrtp_signature,
{
"Signature", "zrtp.signature",
FT_UINT16, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_length,
{
"Length", "zrtp.length",
FT_UINT16, BASE_DEC,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_type,
{
"Type", "zrtp.type",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_version,
{
"ZRTP protocol version", "zrtp.version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_client_id,
{
"Client Identifier", "zrtp.client_source_id",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_hash_image,
{
"Hash Image", "zrtp.hash_image",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_zid,
{
"ZID", "zrtp.zid",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_sigcap,
{
"Sig.capable", "zrtp.sigcap",
FT_BOOLEAN, 8,
NULL, 0x40,
NULL, HFILL
}
},
{&hf_zrtp_msg_mitm,
{
"MiTM", "zrtp.mitm",
FT_BOOLEAN, 8,
NULL, 0x20,
NULL, HFILL
}
},
{&hf_zrtp_msg_passive,
{
"Passive", "zrtp.passive",
FT_BOOLEAN, 8,
NULL, 0x10,
NULL, HFILL
}
},
{&hf_zrtp_msg_hash_count,
{
"Hash Count", "zrtp.hc",
FT_UINT8, BASE_DEC,
NULL, 0x0F,
NULL, HFILL
}
},
{&hf_zrtp_msg_cipher_count,
{
"Cipher Count", "zrtp.cc",
FT_UINT8, BASE_DEC,
NULL, 0xF0,
NULL, HFILL
}
},
{&hf_zrtp_msg_authtag_count,
{
"Auth tag Count", "zrtp.ac",
FT_UINT8, BASE_DEC,
NULL, 0x0F,
NULL, HFILL
}
},
{&hf_zrtp_msg_key_count,
{
"Key Agreement Count", "zrtp.kc",
FT_UINT8, BASE_DEC,
NULL, 0xF0,
NULL, HFILL
}
},
{&hf_zrtp_msg_sas_count,
{
"SAS Count", "zrtp.sc",
FT_UINT8, BASE_DEC,
NULL, 0x0F,
NULL, HFILL
}
},
{&hf_zrtp_msg_hash,
{
"Hash", "zrtp.hash",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_cipher,
{
"Cipher", "zrtp.cipher",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_at,
{
"AT", "zrtp.at",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_keya,
{
"Key Agreement", "zrtp.keya",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_sas,
{
"SAS", "zrtp.sas",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_rs1ID,
{
"rs1ID", "zrtp.rs1id",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_rs2ID,
{
"rs2ID", "zrtp.rs2id",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_auxs,
{
"auxs", "zrtp.auxs",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_pbxs,
{
"pbxs", "zrtp.pbxs",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_hmac,
{
"HMAC", "zrtp.hmac",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_cfb,
{
"CFB", "zrtp.cfb",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_error,
{
"Error", "zrtp.error",
FT_UINT32, BASE_DEC,
VALS(zrtp_error_vals), 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_ping_version,
{
"Ping Version", "zrtp.ping_version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_ping_endpointhash,
{
"Ping Endpoint Hash", "zrtp.ping_endpointhash",
FT_UINT64, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_pingack_endpointhash,
{
"PingAck Endpoint Hash", "zrtp.pingack_endpointhash",
FT_UINT64, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_ping_ssrc,
{
"Ping SSRC", "zrtp.ping_ssrc",
FT_UINT32, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_checksum,
{
"Checksum", "zrtp.checksum",
FT_UINT32, BASE_HEX,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_checksum_status,
{
"Checksum Status", "zrtp.checksum.status",
FT_UINT8, BASE_NONE,
VALS(proto_checksum_vals), 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_hvi,
{
"hvi", "zrtp.hvi",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_nonce,
{
"nonce", "zrtp.nonce",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{&hf_zrtp_msg_key_id,
{
"key ID", "zrtp.key_id",
FT_BYTES, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
}
};
static gint *ett[] = {
&ett_zrtp,
&ett_zrtp_msg,
&ett_zrtp_msg_data,
&ett_zrtp_msg_hc,
&ett_zrtp_msg_kc,
&ett_zrtp_msg_ac,
&ett_zrtp_msg_cc,
&ett_zrtp_msg_sc,
&ett_zrtp_checksum
};
static ei_register_info ei[] = {
{ &ei_zrtp_checksum, { "zrtp.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
};
expert_module_t* expert_zrtp;
proto_zrtp = proto_register_protocol("ZRTP", "ZRTP", "zrtp");
proto_register_field_array(proto_zrtp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
zrtp_handle = register_dissector("zrtp", dissect_zrtp, proto_zrtp);
expert_zrtp = expert_register_protocol(proto_zrtp);
expert_register_field_array(expert_zrtp, ei, array_length(ei));
}
void
proto_reg_handoff_zrtp(void)
{
dissector_add_for_decode_as_with_preference("udp.port", zrtp_handle);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local Variables:
* c-basic-offset: 2
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=2 tabstop=8 expandtab:
* :indentSize=2:tabSize=8:noTabs=true:
*/
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