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wireshark/epan/dissectors/packet-dtls.c
Peter Wu 62100da7f4 TLS: fix RSA decryption with EMS and renegotiation 
The handshake hash is used to derive TLS decryption keys when the
Extended Master Secret (EMS) extension is in use.
ssl_calculate_handshake_hash updates this hash only when the master
secret has not been determined yet.

During TLS renegotiation, there are two master secrets: one before, and
one after. Before this fix, the second calculated master secret is
wrong because the second Client Hello is missing in the handshake hash.
It was missing because the handshake hash was not being updated since
the master secret for the first handshake was still present, and the
decryption state was only reset after that hash update.

To fix this, make sure to clear the SSL_MASTER_SECRET flag before
updating the handshake hash when needed. Additionally, clear the
handshake hash when processing the Client Hello just to make sure that
any previous state is gone.

Fixes #18059
2022-04-25 12:03:32 +00:00

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/* packet-dtls.c
* Routines for dtls dissection
* Copyright (c) 2006, Authesserre Samuel <sauthess@gmail.com>
* Copyright (c) 2007, Mikael Magnusson <mikma@users.sourceforge.net>
* Copyright (c) 2013, Hauke Mehrtens <hauke@hauke-m.de>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
*
* DTLS dissection and decryption.
* See RFC 4347 for details about DTLS specs.
*
* Notes :
* This dissector is based on the TLS dissector (packet-tls.c); Because of the similarity
* of DTLS and TLS, decryption works like TLS with RSA key exchange.
* This dissector uses the sames things (file, libraries) as the TLS dissector (gnutls, packet-tls-utils.h)
* to make it easily maintainable.
*
* It was developed to dissect and decrypt the OpenSSL v 0.9.8f DTLS implementation.
* It is limited to this implementation; there is no complete implementation.
*
* Implemented :
* - DTLS dissection
* - DTLS decryption (openssl one)
*
* Todo :
* - activate correct Mac calculation when openssl will be corrected
* (or if an other implementation works),
* corrected code is ready and commented in packet-tls-utils.h file.
* - add missing things (desegmentation, reordering... that aren't present in actual OpenSSL implementation)
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/to_str.h>
#include <epan/asn1.h>
#include <epan/tap.h>
#include <epan/reassemble.h>
#include <epan/uat.h>
#include <epan/sctpppids.h>
#include <epan/exported_pdu.h>
#include <epan/decode_as.h>
#include <epan/proto_data.h>
#include <epan/secrets.h> /* for privkey_hash_table_new */
#include <wsutil/str_util.h>
#include <wsutil/strtoi.h>
#include <wsutil/utf8_entities.h>
#include <wsutil/rsa.h>
#include "packet-tls-utils.h"
#include "packet-dtls.h"
#include "packet-rtp.h"
#include "packet-rtcp.h"
void proto_register_dtls(void);
#ifdef HAVE_LIBGNUTLS
/* DTLS User Access Table */
static ssldecrypt_assoc_t *dtlskeylist_uats = NULL;
static guint ndtlsdecrypt = 0;
#endif
/* we need to remember the top tree so that subdissectors we call are created
* at the root and not deep down inside the DTLS decode
*/
static proto_tree *top_tree;
/*********************************************************************
*
* Protocol Constants, Variables, Data Structures
*
*********************************************************************/
/* https://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml */
#define SRTP_AES128_CM_HMAC_SHA1_80 0x0001
#define SRTP_AES128_CM_HMAC_SHA1_32 0x0002
#define SRTP_NULL_HMAC_SHA1_80 0x0005
#define SRTP_NULL_HMAC_SHA1_32 0x0006
#define SRTP_AEAD_AES_128_GCM 0x0007
#define SRTP_AEAD_AES_256_GCM 0x0008
static const value_string srtp_protection_profile_vals[] = {
{ SRTP_AES128_CM_HMAC_SHA1_80, "SRTP_AES128_CM_HMAC_SHA1_80" }, /* RFC 5764 */
{ SRTP_AES128_CM_HMAC_SHA1_32, "SRTP_AES128_CM_HMAC_SHA1_32" },
{ SRTP_NULL_HMAC_SHA1_80, "SRTP_NULL_HMAC_SHA1_80" },
{ SRTP_NULL_HMAC_SHA1_32, "SRTP_NULL_HMAC_SHA1_32" },
{ SRTP_AEAD_AES_128_GCM, "SRTP_AEAD_AES_128_GCM" }, /* RFC 7714 */
{ SRTP_AEAD_AES_256_GCM, "SRTP_AEAD_AES_256_GCM" },
{ 0x00, NULL },
};
/* Initialize the protocol and registered fields */
static gint dtls_tap = -1;
static gint exported_pdu_tap = -1;
static gint proto_dtls = -1;
static gint hf_dtls_record = -1;
static gint hf_dtls_record_content_type = -1;
static gint hf_dtls_record_special_type = -1;
static gint hf_dtls_record_version = -1;
static gint hf_dtls_record_epoch = -1;
static gint hf_dtls_record_sequence_number = -1;
static gint hf_dtls_record_connection_id = -1;
static gint hf_dtls_record_length = -1;
static gint hf_dtls_record_appdata = -1;
static gint hf_dtls_record_appdata_proto = -1;
static gint hf_dtls_record_encrypted_content = -1;
static gint hf_dtls_alert_message = -1;
static gint hf_dtls_alert_message_level = -1;
static gint hf_dtls_alert_message_description = -1;
static gint hf_dtls_handshake_protocol = -1;
static gint hf_dtls_handshake_type = -1;
static gint hf_dtls_handshake_length = -1;
static gint hf_dtls_handshake_message_seq = -1;
static gint hf_dtls_handshake_fragment_offset = -1;
static gint hf_dtls_handshake_fragment_length = -1;
static gint hf_dtls_heartbeat_message = -1;
static gint hf_dtls_heartbeat_message_type = -1;
static gint hf_dtls_heartbeat_message_payload_length = -1;
static gint hf_dtls_heartbeat_message_payload = -1;
static gint hf_dtls_heartbeat_message_padding = -1;
static gint hf_dtls_fragments = -1;
static gint hf_dtls_fragment = -1;
static gint hf_dtls_fragment_overlap = -1;
static gint hf_dtls_fragment_overlap_conflicts = -1;
static gint hf_dtls_fragment_multiple_tails = -1;
static gint hf_dtls_fragment_too_long_fragment = -1;
static gint hf_dtls_fragment_error = -1;
static gint hf_dtls_fragment_count = -1;
static gint hf_dtls_reassembled_in = -1;
static gint hf_dtls_reassembled_length = -1;
static gint hf_dtls_hs_ext_use_srtp_protection_profiles_length = -1;
static gint hf_dtls_hs_ext_use_srtp_protection_profile = -1;
static gint hf_dtls_hs_ext_use_srtp_mki_length = -1;
static gint hf_dtls_hs_ext_use_srtp_mki = -1;
/* header fields used in ssl-utils, but defined here. */
static dtls_hfs_t dtls_hfs = { -1, -1 };
/* Initialize the subtree pointers */
static gint ett_dtls = -1;
static gint ett_dtls_record = -1;
static gint ett_dtls_alert = -1;
static gint ett_dtls_handshake = -1;
static gint ett_dtls_heartbeat = -1;
static gint ett_dtls_certs = -1;
static gint ett_dtls_fragment = -1;
static gint ett_dtls_fragments = -1;
static expert_field ei_dtls_handshake_fragment_length_too_long = EI_INIT;
static expert_field ei_dtls_handshake_fragment_length_zero = EI_INIT;
static expert_field ei_dtls_handshake_fragment_past_end_msg = EI_INIT;
static expert_field ei_dtls_msg_len_diff_fragment = EI_INIT;
static expert_field ei_dtls_heartbeat_payload_length = EI_INIT;
static expert_field ei_dtls_cid_invalid_content_type = EI_INIT;
#if 0
static expert_field ei_dtls_cid_invalid_enc_content = EI_INIT;
#endif
#ifdef HAVE_LIBGNUTLS
static GHashTable *dtls_key_hash = NULL;
static wmem_stack_t *key_list_stack = NULL;
static uat_t *dtlsdecrypt_uat = NULL;
static const gchar *dtls_keys_list = NULL;
#endif
static reassembly_table dtls_reassembly_table;
static dissector_table_t dtls_associations = NULL;
static dissector_handle_t dtls_handle = NULL;
static StringInfo dtls_compressed_data = {NULL, 0};
static StringInfo dtls_decrypted_data = {NULL, 0};
static gint dtls_decrypted_data_avail = 0;
static ssl_common_options_t dtls_options = { NULL, NULL};
static const gchar *dtls_debug_file_name = NULL;
static guint32 dtls_default_client_cid_length;
static guint32 dtls_default_server_cid_length;
static heur_dissector_list_t heur_subdissector_list;
static const fragment_items dtls_frag_items = {
/* Fragment subtrees */
&ett_dtls_fragment,
&ett_dtls_fragments,
/* Fragment fields */
&hf_dtls_fragments,
&hf_dtls_fragment,
&hf_dtls_fragment_overlap,
&hf_dtls_fragment_overlap_conflicts,
&hf_dtls_fragment_multiple_tails,
&hf_dtls_fragment_too_long_fragment,
&hf_dtls_fragment_error,
&hf_dtls_fragment_count,
/* Reassembled in field */
&hf_dtls_reassembled_in,
/* Reassembled length field */
&hf_dtls_reassembled_length,
/* Reassembled data field */
NULL,
/* Tag */
"Message fragments"
};
static SSL_COMMON_LIST_T(dissect_dtls_hf);
/* initialize/reset per capture state data (dtls sessions cache) */
static void
dtls_init(void)
{
module_t *dtls_module = prefs_find_module("dtls");
pref_t *keys_list_pref;
ssl_data_alloc(&dtls_decrypted_data, 32);
ssl_data_alloc(&dtls_compressed_data, 32);
/* We should have loaded "keys_list" by now. Mark it obsolete */
if (dtls_module) {
keys_list_pref = prefs_find_preference(dtls_module, "keys_list");
if (! prefs_get_preference_obsolete(keys_list_pref)) {
prefs_set_preference_obsolete(keys_list_pref);
}
}
ssl_init_cid_list();
}
static void
dtls_cleanup(void)
{
ssl_cleanup_cid_list();
#ifdef HAVE_LIBGNUTLS
if (key_list_stack != NULL) {
wmem_destroy_stack(key_list_stack);
key_list_stack = NULL;
}
#endif
g_free(dtls_decrypted_data.data);
g_free(dtls_compressed_data.data);
}
#ifdef HAVE_LIBGNUTLS
/* parse dtls related preferences (private keys and ports association strings) */
static void
dtls_parse_uat(void)
{
guint i, port;
dissector_handle_t handle;
if (dtls_key_hash)
{
g_hash_table_destroy(dtls_key_hash);
}
/* remove only associations created from key list */
if (key_list_stack != NULL) {
while (wmem_stack_count(key_list_stack) > 0) {
port = GPOINTER_TO_UINT(wmem_stack_pop(key_list_stack));
handle = dissector_get_uint_handle(dtls_associations, port);
if (handle != NULL)
ssl_association_remove("dtls.port", dtls_handle, handle, port, FALSE);
}
}
/* parse private keys string, load available keys and put them in key hash*/
dtls_key_hash = privkey_hash_table_new();
ssl_set_debug(dtls_debug_file_name);
if (ndtlsdecrypt > 0)
{
if (key_list_stack == NULL)
key_list_stack = wmem_stack_new(NULL);
for (i = 0; i < ndtlsdecrypt; i++)
{
ssldecrypt_assoc_t *d = &(dtlskeylist_uats[i]);
ssl_parse_key_list(d, dtls_key_hash, "dtls.port", dtls_handle, FALSE);
if (key_list_stack && ws_strtou32(d->port, NULL, &port))
wmem_stack_push(key_list_stack, GUINT_TO_POINTER(port));
}
}
dissector_add_for_decode_as("sctp.port", dtls_handle);
dissector_add_for_decode_as("udp.port", dtls_handle);
}
static void
dtls_reset_uat(void)
{
g_hash_table_destroy(dtls_key_hash);
dtls_key_hash = NULL;
}
static void
dtls_parse_old_keys(void)
{
gchar **old_keys, **parts, *err;
guint i;
gchar *uat_entry;
/* Import old-style keys */
if (dtlsdecrypt_uat && dtls_keys_list && dtls_keys_list[0]) {
old_keys = g_strsplit(dtls_keys_list, ";", 0);
for (i = 0; old_keys[i] != NULL; i++) {
parts = g_strsplit(old_keys[i], ",", 4);
if (parts[0] && parts[1] && parts[2] && parts[3]) {
gchar *path = uat_esc(parts[3], (guint)strlen(parts[3]));
uat_entry = wmem_strdup_printf(NULL, "\"%s\",\"%s\",\"%s\",\"%s\",\"\"",
parts[0], parts[1], parts[2], path);
g_free(path);
if (!uat_load_str(dtlsdecrypt_uat, uat_entry, &err)) {
ssl_debug_printf("dtls_parse: Can't load UAT string %s: %s\n",
uat_entry, err);
g_free(err);
}
wmem_free(NULL, uat_entry);
}
g_strfreev(parts);
}
g_strfreev(old_keys);
}
}
#endif /* HAVE_LIBGNUTLS */
/*
* DTLS Dissection Routines
*
*/
/* record layer dissector */
static gint dissect_dtls_record(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
SslSession *session, gint is_from_server,
SslDecryptSession *conv_data,
guint8 curr_layer_num_ssl);
/* alert message dissector */
static void dissect_dtls_alert(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
const SslSession *session);
/* handshake protocol dissector */
static void dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
guint32 record_length, gboolean maybe_encrypted,
SslSession *session, gint is_from_server,
SslDecryptSession *conv_data, guint8 content_type);
/* heartbeat message dissector */
static void dissect_dtls_heartbeat(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
const SslSession *session, guint32 record_length,
gboolean decrypted);
static int dissect_dtls_hnd_hello_verify_request(ssl_common_dissect_t *hf, tvbuff_t *tvb,
packet_info *pinfo, proto_tree *tree,
guint32 offset, guint32 offset_end);
/*
* Support Functions
*
*/
static gint looks_like_dtls(tvbuff_t *tvb, guint32 offset);
/*********************************************************************
*
* Main dissector
*
*********************************************************************/
/*
* Code to actually dissect the packets
*/
static int
dissect_dtls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
conversation_t *conversation;
proto_item *ti;
proto_tree *dtls_tree;
guint32 offset;
SslDecryptSession *ssl_session = NULL;
SslSession *session = NULL;
gint is_from_server;
guint8 curr_layer_num_ssl = pinfo->curr_layer_num;
ti = NULL;
dtls_tree = NULL;
offset = 0;
ssl_session = NULL;
top_tree = tree;
/* Track the version using conversations allows
* us to more frequently set the protocol column properly
* for continuation data frames.
*
* Also: We use the copy in conv_version as our cached copy,
* so that we don't have to search the conversation
* table every time we want the version; when setting
* the conv_version, must set the copy in the conversation
* in addition to conv_version
*/
conversation = find_or_create_conversation(pinfo);
guint8 record_type = tvb_get_guint8(tvb, offset);
/* try to get decrypt session from the connection ID only for the first pass,
* it should be available from the conversation in the second pass
*/
if (record_type == SSL_ID_TLS12_CID && !PINFO_FD_VISITED(pinfo)) {
// CID length is not embedded in the packet
ssl_session = ssl_get_session_by_cid(tvb, offset+11);
if (ssl_session) {
// update conversation
conversation_add_proto_data(conversation,
dissector_handle_get_protocol_index(dtls_handle),
ssl_session);
}
}
/* if session cannot be retrieved from connection ID, get or create it from conversation */
if (ssl_session == NULL) {
ssl_session = ssl_get_session(conversation, dtls_handle);
}
session = &ssl_session->session;
if (session->last_nontls_frame != 0 &&
session->last_nontls_frame >= pinfo->num) {
/* This conversation started at a different protocol and STARTTLS was
* used, but this packet comes too early. */
return 0;
}
ssl_debug_printf("\ndissect_dtls enter frame #%u (%s)\n", pinfo->num, pinfo->fd->visited ? "already visited" : "first time");
is_from_server = ssl_packet_from_server(session, dtls_associations, pinfo);
/* try decryption only the first time we see this packet
* (to keep cipher synchronized) */
if (pinfo->fd->visited)
ssl_session = NULL;
/* Initialize the protocol column; we'll set it later when we
* figure out what flavor of DTLS it is */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
/* clear the info column */
col_clear(pinfo->cinfo, COL_INFO);
/* Create display subtree for SSL as a whole */
ti = proto_tree_add_item(tree, proto_dtls, tvb, 0, -1, ENC_NA);
dtls_tree = proto_item_add_subtree(ti, ett_dtls);
/* iterate through the records in this tvbuff */
while (tvb_reported_length_remaining(tvb, offset) != 0)
{
/* first try to dispatch off the cached version
* known to be associated with the conversation
*/
switch(session->version) {
case DTLSV1DOT0_VERSION:
case DTLSV1DOT0_OPENSSL_VERSION:
case DTLSV1DOT2_VERSION:
offset = dissect_dtls_record(tvb, pinfo, dtls_tree,
offset, session, is_from_server,
ssl_session, curr_layer_num_ssl);
break;
/* that failed, so apply some heuristics based
* on this individual packet
*/
default:
if (looks_like_dtls(tvb, offset))
{
/* looks like dtls */
offset = dissect_dtls_record(tvb, pinfo, dtls_tree,
offset, session, is_from_server,
ssl_session, curr_layer_num_ssl);
}
else
{
/* looks like something unknown, so lump into
* continuation data
*/
offset = tvb_reported_length(tvb);
col_append_sep_str(pinfo->cinfo, COL_INFO,
NULL, "Continuation Data");
/* Set the protocol column */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
}
break;
}
}
// XXX there is no Follow DTLS Stream, is this tap needed?
tap_queue_packet(dtls_tap, pinfo, NULL);
return tvb_captured_length(tvb);
}
static guint8 dtls_cid_length(SslSession *session, gboolean is_from_server)
{
guint8 cid_length;
if (is_from_server) {
if (session && session->client_cid_len_present) {
cid_length = session->client_cid_len;
} else {
cid_length = (guint8)dtls_default_client_cid_length;
}
} else {
if (session && session->server_cid_len_present) {
cid_length = session->server_cid_len;
} else {
cid_length = (guint8)dtls_default_server_cid_length;
}
}
return cid_length;
}
static gboolean
dissect_dtls_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
/* Stronger confirmation of DTLS packet is provided by verifying the
* captured payload length against the remainder of the UDP packet size. */
guint length = tvb_captured_length(tvb);
guint offset = 0;
if (tvb_reported_length(tvb) == length) {
/* The entire payload was captured. */
while (offset + 13 <= length && looks_like_dtls(tvb, offset)) {
/* Advance offset to the end of the current DTLS record */
guint8 record_type = tvb_get_guint8(tvb, offset);
if (record_type == SSL_ID_TLS12_CID) {
/* CID length is not embedded in the packet */
SslDecryptSession *ssl_session = ssl_get_session_by_cid(tvb, offset + 11);
SslSession *session = ssl_session ? &ssl_session->session : NULL;
gint is_from_server = ssl_packet_from_server(session, dtls_associations, pinfo);
offset += dtls_cid_length(session, is_from_server);
}
offset += tvb_get_ntohs(tvb, offset + 11) + 13;
if (offset == length) {
dissect_dtls(tvb, pinfo, tree, data);
return TRUE;
}
}
if (pinfo->fragmented && offset >= 13) {
dissect_dtls(tvb, pinfo, tree, data);
return TRUE;
}
return FALSE;
}
/* This packet was truncated by the capture process due to a snapshot
* length - do our best with what we've got. */
while (tvb_captured_length_remaining(tvb, offset) >= 3) {
if (!looks_like_dtls(tvb, offset))
return FALSE;
offset += 3;
if (tvb_captured_length_remaining(tvb, offset) >= 10 ) {
offset += tvb_get_ntohs(tvb, offset + 8) + 10;
} else {
/* Dissect what we've got, which might be as little as 3 bytes. */
dissect_dtls(tvb, pinfo, tree, data);
return TRUE;
}
if (offset == length) {
/* Can this ever happen? Well, just in case ... */
dissect_dtls(tvb, pinfo, tree, data);
return TRUE;
}
}
/* One last check to see if the current offset is at least less than the
* original number of bytes present before truncation or we're dealing with
* a packet fragment that's also been truncated. */
if ((length >= 3) && (offset <= tvb_reported_length(tvb) || pinfo->fragmented)) {
dissect_dtls(tvb, pinfo, tree, data);
return TRUE;
}
return FALSE;
}
static gboolean
dtls_is_null_cipher(guint cipher )
{
switch(cipher) {
case 0x0000:
case 0x0001:
case 0x0002:
case 0x002c:
case 0x002d:
case 0x002e:
case 0x003b:
case 0x00b0:
case 0x00b1:
case 0x00b4:
case 0x00b5:
case 0x00b8:
case 0x00b9:
case 0xc001:
case 0xc006:
case 0xc00b:
case 0xc010:
case 0xc015:
case 0xc039:
case 0xc03a:
case 0xc03b:
return TRUE;
default:
return FALSE;
}
}
static void
dtls_save_decrypted_record(packet_info *pinfo, gint record_id, guint8 content_type, guint8 curr_layer_num_ssl)
{
const guchar *data = dtls_decrypted_data.data;
guint datalen = dtls_decrypted_data_avail;
if (datalen == 0) {
return;
}
if (content_type == SSL_ID_TLS12_CID) {
/*
* The actual data is followed by the content type and then zero or
* more padding. Scan backwards for content type, skipping padding.
*/
while (datalen > 0 && data[datalen - 1] == 0) {
datalen--;
}
ssl_debug_printf("%s found %d padding bytes\n", G_STRFUNC, dtls_decrypted_data_avail - datalen);
if (datalen == 0) {
ssl_debug_printf("%s there is no room for content type!\n", G_STRFUNC);
return;
}
content_type = data[--datalen];
if (datalen == 0) {
return;
}
}
ssl_add_record_info(proto_dtls, pinfo, data, datalen, record_id, NULL, (ContentType)content_type, curr_layer_num_ssl);
}
static gboolean
decrypt_dtls_record(tvbuff_t *tvb, packet_info *pinfo, guint32 offset, SslDecryptSession *ssl,
guint8 content_type, guint16 record_version, guint16 record_length, guint8 curr_layer_num_ssl,
const guchar *cid, guint8 cid_length)
{
gboolean success;
SslDecoder *decoder;
/* if we can decrypt and decryption have success
* add decrypted data to this packet info */
if (!ssl || !(ssl->state & SSL_HAVE_SESSION_KEY)) {
ssl_debug_printf("decrypt_dtls_record: no session key\n");
return FALSE;
}
ssl_debug_printf("decrypt_dtls_record: app_data len %d, ssl state %X\n",
record_length, ssl->state);
/* retrieve decoder for this packet direction */
if (ssl_packet_from_server(&ssl->session, dtls_associations, pinfo) != 0) {
ssl_debug_printf("decrypt_dtls_record: using server decoder\n");
decoder = ssl->server;
}
else {
ssl_debug_printf("decrypt_dtls_record: using client decoder\n");
decoder = ssl->client;
}
if (!decoder && !dtls_is_null_cipher(ssl->session.cipher)) {
ssl_debug_printf("decrypt_dtls_record: no decoder available\n");
return FALSE;
}
/* ensure we have enough storage space for decrypted data */
if (record_length > dtls_decrypted_data.data_len)
{
ssl_debug_printf("decrypt_dtls_record: allocating %d bytes"
" for decrypt data (old len %d)\n",
record_length + 32, dtls_decrypted_data.data_len);
dtls_decrypted_data.data = (guchar *)g_realloc(dtls_decrypted_data.data,
record_length + 32);
dtls_decrypted_data.data_len = record_length + 32;
}
/* run decryption and add decrypted payload to protocol data, if decryption
* is successful*/
dtls_decrypted_data_avail = dtls_decrypted_data.data_len;
if (ssl->state & SSL_HAVE_SESSION_KEY) {
if (!decoder) {
ssl_debug_printf("decrypt_dtls_record: no decoder available\n");
return FALSE;
}
success = ssl_decrypt_record(ssl, decoder, content_type, record_version, FALSE,
tvb_get_ptr(tvb, offset, record_length), record_length, cid, cid_length,
&dtls_compressed_data, &dtls_decrypted_data, &dtls_decrypted_data_avail) == 0;
}
else if (dtls_is_null_cipher(ssl->session.cipher)) {
/* Non-encrypting cipher NULL-XXX */
tvb_memcpy(tvb, dtls_decrypted_data.data, offset, record_length);
dtls_decrypted_data_avail = dtls_decrypted_data.data_len = record_length;
success = TRUE;
} else {
success = FALSE;
}
if (success) {
dtls_save_decrypted_record(pinfo, tvb_raw_offset(tvb)+offset, content_type, curr_layer_num_ssl);
}
return success;
}
static void
export_pdu_packet(tvbuff_t *tvb, packet_info *pinfo, guint8 tag, const gchar *name)
{
exp_pdu_data_t *exp_pdu_data = export_pdu_create_common_tags(pinfo, name, tag);
exp_pdu_data->tvb_captured_length = tvb_captured_length(tvb);
exp_pdu_data->tvb_reported_length = tvb_reported_length(tvb);
exp_pdu_data->pdu_tvb = tvb;
tap_queue_packet(exported_pdu_tap, pinfo, exp_pdu_data);
}
/*********************************************************************
*
* DTLS Dissection Routines
*
*********************************************************************/
static gint
dissect_dtls_record(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
SslSession *session, gint is_from_server,
SslDecryptSession* ssl,
guint8 curr_layer_num_ssl)
{
/*
* struct {
* uint8 major, minor;
* } ProtocolVersion;
*
*
* enum {
* change_cipher_spec(20), alert(21), handshake(22),
* application_data(23), (255)
* } ContentType;
*
* struct {
* ContentType type;
* ProtocolVersion version;
* uint16 epoch; // New field
* uint48 sequence_number; // New field
* uint16 length;
* opaque fragment[TLSPlaintext.length];
* } DTLSPlaintext;
*
*
* draft-ietf-tls-dtls-connection-id-07:
*
* struct {
* ContentType special_type = tls12_cid;
* ProtocolVersion version;
* uint16 epoch;
* uint48 sequence_number;
* opaque cid[cid_length]; // New field
* uint16 length;
* opaque enc_content[DTLSCiphertext.length];
* } DTLSCiphertext;
*
*/
guint32 dtls_record_length;
guint32 record_length;
guint16 version;
guint16 epoch;
guint64 sequence_number;
guint8 content_type;
guint content_type_offset;
guint8 next_byte;
proto_tree *ti;
proto_tree *dtls_record_tree;
proto_item *length_pi, *ct_pi;
tvbuff_t *decrypted;
SslRecordInfo *record = NULL;
heur_dtbl_entry_t *hdtbl_entry;
guint8 *cid = NULL;
guint8 cid_length;
/* Connection ID length to use if any */
cid_length = dtls_cid_length(session, is_from_server);
/*
* Get the record layer fields of interest
*/
content_type = tvb_get_guint8(tvb, offset);
version = tvb_get_ntohs(tvb, offset + 1);
epoch = tvb_get_ntohs(tvb, offset + 3);
sequence_number = tvb_get_ntoh48(tvb, offset + 5);
if (content_type == SSL_ID_TLS12_CID && cid_length > 0) {
cid = tvb_memdup(wmem_packet_scope(), tvb, offset + 11, cid_length);
record_length = tvb_get_ntohs(tvb, offset + cid_length + 11);
dtls_record_length = 13 + cid_length + record_length;
} else {
record_length = tvb_get_ntohs(tvb, offset + 11);
dtls_record_length = 13 + record_length;
}
if (!ssl_is_valid_content_type(content_type)) {
/* if we don't have a valid content_type, there's no sense
* continuing any further
*/
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Continuation Data");
/* Set the protocol column */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
return offset + dtls_record_length;
}
if (ssl) {
if (is_from_server) {
if (ssl->server) {
ssl->server->seq = sequence_number;
ssl->server->epoch = epoch;
}
} else {
if (ssl->client) {
ssl->client->seq = sequence_number;
ssl->client->epoch = epoch;
}
}
}
/*
* If GUI, fill in record layer part of tree
*/
/* add the record layer subtree header */
ti = proto_tree_add_item(tree, hf_dtls_record, tvb,
offset, dtls_record_length, ENC_NA);
dtls_record_tree = proto_item_add_subtree(ti, ett_dtls_record);
/* show the one-byte content type */
if (content_type == SSL_ID_TLS12_CID) {
ct_pi = proto_tree_add_item(dtls_record_tree, hf_dtls_record_special_type,
tvb, offset, 1, ENC_BIG_ENDIAN);
} else {
ct_pi = proto_tree_add_item(dtls_record_tree, hf_dtls_record_content_type,
tvb, offset, 1, ENC_BIG_ENDIAN);
}
content_type_offset = offset;
offset++;
/* add the version */
proto_tree_add_item(dtls_record_tree, hf_dtls_record_version, tvb,
offset, 2, ENC_BIG_ENDIAN);
offset += 2;
/* show epoch */
proto_tree_add_uint(dtls_record_tree, hf_dtls_record_epoch, tvb, offset, 2, epoch);
offset += 2;
/* add sequence_number */
proto_tree_add_uint64(dtls_record_tree, hf_dtls_record_sequence_number, tvb, offset, 6, sequence_number);
offset += 6;
if (content_type == SSL_ID_TLS12_CID) {
/* add connection ID */
proto_tree_add_item(dtls_record_tree, hf_dtls_record_connection_id, tvb, offset, cid_length, ENC_NA);
offset += cid_length;
}
/* add the length */
length_pi = proto_tree_add_uint(dtls_record_tree, hf_dtls_record_length, tvb,
offset, 2, record_length);
offset += 2; /* move past length field itself */
/*
* if we don't already have a version set for this conversation,
* but this message's version is authoritative (i.e., it's
* not client_hello, then save the version to the conversation
* structure and print the column version
*/
next_byte = tvb_get_guint8(tvb, offset);
if (session->version == SSL_VER_UNKNOWN)
ssl_try_set_version(session, ssl, content_type, next_byte, TRUE, version);
col_set_str(pinfo->cinfo, COL_PROTOCOL,
val_to_str_const(session->version, ssl_version_short_names, "DTLS"));
/*
* now dissect the next layer
*/
ssl_debug_printf("dissect_dtls_record: content_type %d epoch %d seq %"PRIu64"\n", content_type, epoch, sequence_number);
/* try to decrypt record on the first pass, if possible. Store decrypted
* record for later usage (without having to decrypt again). */
if (ssl) {
decrypt_dtls_record(tvb, pinfo, offset, ssl, content_type, version, record_length, curr_layer_num_ssl, cid, cid_length);
}
decrypted = ssl_get_record_info(tvb, proto_dtls, pinfo, tvb_raw_offset(tvb)+offset, curr_layer_num_ssl, &record);
if (decrypted) {
add_new_data_source(pinfo, decrypted, "Decrypted DTLS");
if (content_type == SSL_ID_TLS12_CID) {
content_type = record->type;
ti = proto_tree_add_uint(dtls_record_tree, hf_dtls_record_content_type,
tvb, content_type_offset, 1, record->type);
proto_item_set_generated(ti);
}
}
ssl_check_record_length(&dissect_dtls_hf, pinfo, (ContentType)content_type, record_length, length_pi, session->version, decrypted);
/* extract the real record from the connection ID record */
if (content_type == SSL_ID_TLS12_CID) {
proto_item_set_text(dtls_record_tree, "%s Record Layer: Connection ID",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"));
/* if content cannot be deciphered or the content is invalid */
if (decrypted == NULL) {
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Connection ID");
proto_tree_add_item(dtls_record_tree, hf_dtls_record_encrypted_content, tvb,
offset, record_length, ENC_NA);
offset += record_length; /* skip to end of record */
return offset;
}
}
switch ((ContentType) content_type) {
case SSL_ID_CHG_CIPHER_SPEC:
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Change Cipher Spec");
ssl_dissect_change_cipher_spec(&dissect_dtls_hf, tvb, pinfo,
dtls_record_tree, offset, session,
is_from_server, ssl);
if (ssl) {
ssl_finalize_decryption(ssl, tls_get_master_key_map(TRUE));
ssl_change_cipher(ssl, is_from_server);
}
/* Heuristic: any later ChangeCipherSpec is not a resumption of this
* session. Set the flag after ssl_finalize_decryption such that it has
* a chance to use resume using Session Tickets. */
if (is_from_server)
session->is_session_resumed = FALSE;
break;
case SSL_ID_ALERT:
{
/* try to retrieve and use decrypted alert record, if any. */
if (decrypted) {
dissect_dtls_alert(decrypted, pinfo, dtls_record_tree, 0,
session);
} else {
dissect_dtls_alert(tvb, pinfo, dtls_record_tree, offset,
session);
}
break;
}
case SSL_ID_HANDSHAKE:
{
/* try to retrieve and use decrypted handshake record, if any. */
if (decrypted) {
dissect_dtls_handshake(decrypted, pinfo, dtls_record_tree, 0,
tvb_reported_length(decrypted), FALSE, session, is_from_server,
ssl, content_type);
} else {
dissect_dtls_handshake(tvb, pinfo, dtls_record_tree, offset,
record_length, TRUE, session, is_from_server, ssl,
content_type);
}
break;
}
case SSL_ID_APP_DATA:
/* show on info column what we are decoding */
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Application Data");
/* app_handle discovery is done here instead of dissect_dtls_payload()
* because the protocol name needs to be displayed below. */
if (!session->app_handle) {
/* Unknown protocol handle, ssl_starttls_ack was not called before.
* Try to find an appropriate dissection handle and cache it. */
dissector_handle_t handle;
handle = dissector_get_uint_handle(dtls_associations, pinfo->srcport);
handle = handle ? handle : dissector_get_uint_handle(dtls_associations, pinfo->destport);
if (handle) session->app_handle = handle;
}
proto_item_set_text(dtls_record_tree,
"%s Record Layer: %s Protocol: %s",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"),
val_to_str_const(content_type, ssl_31_content_type, "unknown"),
session->app_handle
? dissector_handle_get_dissector_name(session->app_handle)
: "Application Data");
proto_tree_add_item(dtls_record_tree, hf_dtls_record_appdata, tvb,
offset, record_length, ENC_NA);
if (session->app_handle) {
ti = proto_tree_add_string(dtls_record_tree, hf_dtls_record_appdata_proto, tvb, 0, 0, dissector_handle_get_dissector_name(session->app_handle));
proto_item_set_generated(ti);
}
/* show decrypted data info, if available */
if (decrypted)
{
gboolean dissected;
guint16 saved_match_port;
/* try to dissect decrypted data*/
ssl_debug_printf("%s decrypted len %d\n", G_STRFUNC, record->data_len);
saved_match_port = pinfo->match_uint;
if (is_from_server) {
pinfo->match_uint = pinfo->srcport;
} else {
pinfo->match_uint = pinfo->destport;
}
/* find out a dissector using server port*/
if (session->app_handle) {
ssl_debug_printf("%s: found handle %p (%s)\n", G_STRFUNC,
(void *)session->app_handle,
dissector_handle_get_dissector_name(session->app_handle));
ssl_print_data("decrypted app data", record->plain_data, record->data_len);
if (have_tap_listener(exported_pdu_tap)) {
export_pdu_packet(decrypted, pinfo, EXP_PDU_TAG_PROTO_NAME,
dissector_handle_get_dissector_name(session->app_handle));
}
dissected = call_dissector_only(session->app_handle, decrypted, pinfo, top_tree, NULL);
}
else {
/* try heuristic subdissectors */
dissected = dissector_try_heuristic(heur_subdissector_list, decrypted, pinfo, top_tree, &hdtbl_entry, NULL);
if (dissected && have_tap_listener(exported_pdu_tap)) {
export_pdu_packet(decrypted, pinfo, EXP_PDU_TAG_HEUR_PROTO_NAME, hdtbl_entry->short_name);
}
}
pinfo->match_uint = saved_match_port;
/* fallback to data dissector */
if (!dissected)
call_data_dissector(decrypted, pinfo, top_tree);
}
break;
case SSL_ID_HEARTBEAT:
/* try to retrieve and use decrypted alert record, if any. */
if (decrypted) {
dissect_dtls_heartbeat(decrypted, pinfo, dtls_record_tree, 0,
session, tvb_reported_length (decrypted), TRUE);
} else {
dissect_dtls_heartbeat(tvb, pinfo, dtls_record_tree, offset,
session, record_length, FALSE);
}
break;
case SSL_ID_TLS12_CID:
expert_add_info_format(pinfo, ct_pi, &ei_dtls_cid_invalid_content_type,
"Invalid content type (%d)", content_type);
break;
}
offset += record_length; /* skip to end of record */
return offset;
}
/* dissects the alert message, filling in the tree */
static void
dissect_dtls_alert(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
const SslSession *session)
{
/* struct {
* AlertLevel level;
* AlertDescription description;
* } Alert;
*/
proto_tree *ti;
proto_tree *ssl_alert_tree;
const gchar *level;
const gchar *desc;
guint8 byte;
ti = proto_tree_add_item(tree, hf_dtls_alert_message, tvb,
offset, 2, ENC_NA);
ssl_alert_tree = proto_item_add_subtree(ti, ett_dtls_alert);
/*
* set the record layer label
*/
/* first lookup the names for the alert level and description */
byte = tvb_get_guint8(tvb, offset); /* grab the level byte */
level = try_val_to_str(byte, ssl_31_alert_level);
byte = tvb_get_guint8(tvb, offset+1); /* grab the desc byte */
desc = try_val_to_str(byte, ssl_31_alert_description);
/* now set the text in the record layer line */
if (level && desc)
{
col_append_sep_fstr(pinfo->cinfo, COL_INFO,
NULL, "Alert (Level: %s, Description: %s)",
level, desc);
}
else
{
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Encrypted Alert");
}
if (tree)
{
if (level && desc)
{
proto_item_set_text(tree, "%s Record Layer: Alert "
"(Level: %s, Description: %s)",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"),
level, desc);
proto_tree_add_item(ssl_alert_tree, hf_dtls_alert_message_level,
tvb, offset++, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(ssl_alert_tree, hf_dtls_alert_message_description,
tvb, offset, 1, ENC_BIG_ENDIAN);
}
else
{
proto_item_set_text(tree,
"%s Record Layer: Encrypted Alert",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"));
proto_item_set_text(ssl_alert_tree,
"Alert Message: Encrypted Alert");
}
}
}
/* dissects the handshake protocol, filling the tree */
static void
dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
guint32 record_length, gboolean maybe_encrypted,
SslSession *session, gint is_from_server,
SslDecryptSession* ssl, guint8 content_type)
{
/* struct {
* HandshakeType msg_type;
* uint24 length;
* uint16 message_seq; //new field
* uint24 fragment_offset; //new field
* uint24 fragment_length; //new field
* select (HandshakeType) {
* case hello_request: HelloRequest;
* case client_hello: ClientHello;
* case server_hello: ServerHello;
* case hello_verify_request: HelloVerifyRequest; //new field
* case certificate: Certificate;
* case server_key_exchange: ServerKeyExchange;
* case certificate_request: CertificateRequest;
* case server_hello_done: ServerHelloDone;
* case certificate_verify: CertificateVerify;
* case client_key_exchange: ClientKeyExchange;
* case finished: Finished;
* } body;
* } Handshake;
*/
proto_tree *ti, *length_item = NULL, *fragment_length_item = NULL;
proto_tree *ssl_hand_tree;
const gchar *msg_type_str;
guint8 msg_type;
guint32 length;
guint16 message_seq;
guint32 fragment_offset;
guint32 fragment_length;
gboolean first_iteration;
guint32 reassembled_length;
tvbuff_t *sub_tvb;
msg_type_str = NULL;
first_iteration = TRUE;
/* just as there can be multiple records per packet, there
* can be multiple messages per record as long as they have
* the same content type
*
* we really only care about this for handshake messages
*/
/* set record_length to the max offset */
record_length += offset;
for (; offset < record_length; offset += fragment_length,
first_iteration = FALSE) /* set up for next pass, if any */
{
fragment_head *frag_msg = NULL;
tvbuff_t *new_tvb = NULL;
const gchar *frag_str = NULL;
gboolean fragmented;
guint32 hs_offset = offset;
/* add a subtree for the handshake protocol */
ti = proto_tree_add_item(tree, hf_dtls_handshake_protocol, tvb, offset, -1, ENC_NA);
ssl_hand_tree = proto_item_add_subtree(ti, ett_dtls_handshake);
msg_type = tvb_get_guint8(tvb, offset);
fragment_length = tvb_get_ntoh24(tvb, offset + 9);
/* Check the fragment length in the handshake message. Assume it's an
* encrypted handshake message if the message would pass
* the record_length boundary. This is a workaround for the
* situation where the first octet of the encrypted handshake
* message is actually a known handshake message type.
*/
if (!maybe_encrypted || offset + fragment_length <= record_length)
msg_type_str = try_val_to_str(msg_type, ssl_31_handshake_type);
if (!msg_type_str && !first_iteration)
{
/* only dissect / report messages if they're
* either the first message in this record
* or they're a valid message type
*/
return;
}
/*
* Update our info string
*/
if (msg_type_str)
{
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, msg_type_str);
}
else
{
/* if we don't have a valid handshake type, just quit dissecting */
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Encrypted Handshake Message");
return;
}
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_type,
tvb, offset, 1, msg_type);
offset++;
length = tvb_get_ntoh24(tvb, offset);
length_item = proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_length,
tvb, offset, 3, length);
offset += 3;
message_seq = tvb_get_ntohs(tvb,offset);
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_message_seq,
tvb, offset, 2, message_seq);
offset += 2;
fragment_offset = tvb_get_ntoh24(tvb, offset);
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_fragment_offset,
tvb, offset, 3, fragment_offset);
offset += 3;
fragment_length_item = proto_tree_add_uint(ssl_hand_tree,
hf_dtls_handshake_fragment_length,
tvb, offset, 3,
fragment_length);
offset += 3;
proto_item_set_len(ti, fragment_length + 12);
fragmented = FALSE;
if (fragment_length + fragment_offset > length)
{
if (fragment_offset == 0)
{
expert_add_info(pinfo, fragment_length_item, &ei_dtls_handshake_fragment_length_too_long);
}
else
{
fragmented = TRUE;
expert_add_info(pinfo, fragment_length_item, &ei_dtls_handshake_fragment_past_end_msg);
}
}
else if (fragment_offset > 0 && fragment_length == 0)
{
/* Fragmented message, but no actual fragment... Note that if a
* fragment was previously completed (reassembled_length == length),
* it is already dissected. */
expert_add_info(pinfo, fragment_length_item, &ei_dtls_handshake_fragment_length_zero);
continue;
}
else if (fragment_length < length)
{
fragmented = TRUE;
/* Handle fragments of known message type, ignore others */
if (ssl_is_valid_handshake_type(msg_type, TRUE))
{
/* Fragmented handshake message */
pinfo->fragmented = TRUE;
/* Don't pass the reassembly code data that doesn't exist */
tvb_ensure_bytes_exist(tvb, offset, fragment_length);
frag_msg = fragment_add(&dtls_reassembly_table,
tvb, offset, pinfo, message_seq, NULL,
fragment_offset, fragment_length, TRUE);
/*
* Do we already have a length for this reassembly?
*/
reassembled_length = fragment_get_tot_len(&dtls_reassembly_table,
pinfo, message_seq, NULL);
if (reassembled_length == 0)
{
/* No - set it to the length specified by this packet. */
fragment_set_tot_len(&dtls_reassembly_table,
pinfo, message_seq, NULL, length);
}
else
{
/* Yes - if this packet specifies a different length,
report an error. */
if (reassembled_length != length)
{
expert_add_info(pinfo, length_item, &ei_dtls_msg_len_diff_fragment);
}
}
if (frag_msg && (fragment_length + fragment_offset) == reassembled_length)
{
/* Reassembled */
new_tvb = process_reassembled_data(tvb, offset, pinfo,
"Reassembled DTLS",
frag_msg,
&dtls_frag_items,
NULL, tree);
frag_str = " (Reassembled)";
}
else
{
frag_str = " (Fragment)";
}
col_append_str(pinfo->cinfo, COL_INFO, frag_str);
}
}
if (tree)
{
/* set the label text on the record layer expanding node */
if (first_iteration)
{
proto_item_set_text(tree, "%s Record Layer: %s Protocol: %s%s",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"),
val_to_str_const(content_type, ssl_31_content_type, "unknown"),
msg_type_str, (frag_str!=NULL) ? frag_str : "");
}
else
{
proto_item_set_text(tree, "%s Record Layer: %s Protocol: %s%s",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"),
val_to_str_const(content_type, ssl_31_content_type, "unknown"),
"Multiple Handshake Messages",
(frag_str!=NULL) ? frag_str : "");
}
if (ssl_hand_tree)
{
/* set the text label on the subtree node */
proto_item_set_text(ssl_hand_tree, "Handshake Protocol: %s%s",
msg_type_str, (frag_str!=NULL) ? frag_str : "");
}
}
if (fragmented && !new_tvb)
{
/* Skip fragmented messages not reassembled yet */
continue;
}
if (new_tvb)
{
sub_tvb = new_tvb;
}
else
{
sub_tvb = tvb_new_subset_length(tvb, offset, fragment_length);
}
if ((msg_type == SSL_HND_CLIENT_HELLO || msg_type == SSL_HND_SERVER_HELLO)) {
/* Prepare for renegotiation by resetting the state. */
ssl_reset_session(session, ssl, msg_type == SSL_HND_CLIENT_HELLO);
}
/*
* Add handshake message (including type, length, etc.) to hash (for
* Extended Master Secret). The computation must however happen as if
* the message was sent in a single fragment (RFC 6347, section 4.2.6).
*
* Skip CertificateVerify since the handshake hash covers just
* ClientHello up to and including ClientKeyExchange, but the keys are
* actually retrieved in ChangeCipherSpec (which comes after that).
*/
if (msg_type != SSL_HND_CERT_VERIFY) {
if (fragment_offset == 0) {
/* Unfragmented packet. */
ssl_calculate_handshake_hash(ssl, tvb, hs_offset, 12 + fragment_length);
} else {
/*
* Handshake message was fragmented over multiple messages, fake a
* single fragment and add reassembled data.
*/
/* msg_type (1), length (3), message_seq (2) */
ssl_calculate_handshake_hash(ssl, tvb, hs_offset, 6);
/* fragment_offset (3) equals to zero. */
ssl_calculate_handshake_hash(ssl, NULL, 0, 3);
/* fragment_length (3) equals to length. */
ssl_calculate_handshake_hash(ssl, tvb, hs_offset + 1, 3);
/* actual handshake data */
ssl_calculate_handshake_hash(ssl, sub_tvb, 0, length);
}
}
/* now dissect the handshake message, if necessary */
switch ((HandshakeType) msg_type) {
case SSL_HND_HELLO_REQUEST:
/* hello_request has no fields, so nothing to do! */
break;
case SSL_HND_CLIENT_HELLO:
if (ssl) {
/* ClientHello is first packet so set direction */
ssl_set_server(session, &pinfo->dst, pinfo->ptype, pinfo->destport);
}
ssl_dissect_hnd_cli_hello(&dissect_dtls_hf, sub_tvb, pinfo,
ssl_hand_tree, 0, length, session, ssl,
&dtls_hfs);
break;
case SSL_HND_SERVER_HELLO:
ssl_try_set_version(session, ssl, SSL_ID_HANDSHAKE, SSL_HND_SERVER_HELLO, TRUE,
tvb_get_ntohs(sub_tvb, 0));
ssl_dissect_hnd_srv_hello(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree,
0, length, session, ssl, TRUE, FALSE);
break;
case SSL_HND_HELLO_VERIFY_REQUEST:
/*
* The initial ClientHello and HelloVerifyRequest are not included
* in the calculation of the handshake_messages
* (https://tools.ietf.org/html/rfc6347#page-18). This is also
* important for correct calculation of Extended Master Secret.
*/
if (ssl && ssl->handshake_data.data_len) {
ssl_debug_printf("%s erasing previous handshake_messages: %d\n", G_STRFUNC, ssl->handshake_data.data_len);
wmem_free(wmem_file_scope(), ssl->handshake_data.data);
ssl->handshake_data.data = NULL;
ssl->handshake_data.data_len = 0;
}
dissect_dtls_hnd_hello_verify_request(&dissect_dtls_hf, sub_tvb, pinfo,
ssl_hand_tree, 0, length);
break;
case SSL_HND_NEWSESSION_TICKET:
/* no need to load keylog file here as it only links a previous
* master key with this Session Ticket */
ssl_dissect_hnd_new_ses_ticket(&dissect_dtls_hf, sub_tvb, pinfo,
ssl_hand_tree, 0, length, session, ssl, TRUE,
tls_get_master_key_map(FALSE)->tickets);
break;
case SSL_HND_HELLO_RETRY_REQUEST:
ssl_dissect_hnd_hello_retry_request(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree,
0, length, session, ssl, TRUE);
break;
case SSL_HND_CERTIFICATE:
ssl_dissect_hnd_cert(&dissect_dtls_hf, sub_tvb, ssl_hand_tree, 0, length,
pinfo, session, ssl, is_from_server, TRUE);
break;
case SSL_HND_SERVER_KEY_EXCHG:
ssl_dissect_hnd_srv_keyex(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree, 0, length, session);
break;
case SSL_HND_CERT_REQUEST:
ssl_dissect_hnd_cert_req(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree, 0, length, session, TRUE);
break;
case SSL_HND_SVR_HELLO_DONE:
/* This is not an abbreviated handshake, it is certainly not resumed. */
session->is_session_resumed = FALSE;
break;
case SSL_HND_CERT_VERIFY:
ssl_dissect_hnd_cli_cert_verify(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree, 0, length, session->version);
break;
case SSL_HND_CLIENT_KEY_EXCHG:
ssl_dissect_hnd_cli_keyex(&dissect_dtls_hf, sub_tvb, ssl_hand_tree, 0, length, session);
if (!ssl)
break;
/* try to find master key from pre-master key */
if (!ssl_generate_pre_master_secret(ssl, length, sub_tvb, 0,
dtls_options.psk,
#ifdef HAVE_LIBGNUTLS
dtls_key_hash,
#endif
tls_get_master_key_map(TRUE))) {
ssl_debug_printf("dissect_dtls_handshake can't generate pre master secret\n");
}
break;
case SSL_HND_FINISHED:
ssl_dissect_hnd_finished(&dissect_dtls_hf, sub_tvb, ssl_hand_tree,
0, length, session, NULL);
break;
case SSL_HND_CERT_STATUS:
tls_dissect_hnd_certificate_status(&dissect_dtls_hf, sub_tvb, pinfo, ssl_hand_tree, 0, length);
break;
case SSL_HND_CERT_URL:
case SSL_HND_SUPPLEMENTAL_DATA:
case SSL_HND_KEY_UPDATE:
case SSL_HND_ENCRYPTED_EXTS:
case SSL_HND_END_OF_EARLY_DATA: /* TLS 1.3 */
case SSL_HND_COMPRESSED_CERTIFICATE:
case SSL_HND_ENCRYPTED_EXTENSIONS: /* TLS 1.3 */
/* TODO: does this need further dissection? */
break;
}
}
}
/* dissects the heartbeat message, filling in the tree */
static void
dissect_dtls_heartbeat(tvbuff_t *tvb, packet_info *pinfo,
proto_tree *tree, guint32 offset,
const SslSession *session, guint32 record_length,
gboolean decrypted)
{
/* struct {
* HeartbeatMessageType type;
* uint16 payload_length;
* opaque payload;
* opaque padding;
* } HeartbeatMessage;
*/
proto_tree *ti;
proto_tree *dtls_heartbeat_tree;
const gchar *type;
guint8 byte;
guint16 payload_length;
guint16 padding_length;
ti = proto_tree_add_item(tree, hf_dtls_heartbeat_message, tvb,
offset, record_length - 32, ENC_NA);
dtls_heartbeat_tree = proto_item_add_subtree(ti, ett_dtls_heartbeat);
/*
* set the record layer label
*/
/* first lookup the names for the message type and the payload length */
byte = tvb_get_guint8(tvb, offset);
type = try_val_to_str(byte, tls_heartbeat_type);
payload_length = tvb_get_ntohs(tvb, offset + 1);
padding_length = record_length - 3 - payload_length;
/* now set the text in the record layer line */
if (type && (payload_length <= record_length - 16 - 3)) {
col_append_sep_fstr(pinfo->cinfo, COL_INFO, NULL, "Heartbeat %s", type);
} else {
col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "Encrypted Heartbeat");
}
if (tree) {
if (type && ((payload_length <= record_length - 16 - 3) || decrypted)) {
proto_item_set_text(tree, "%s Record Layer: Heartbeat "
"%s",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"),
type);
proto_tree_add_item(dtls_heartbeat_tree, hf_dtls_heartbeat_message_type,
tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
ti = proto_tree_add_uint(dtls_heartbeat_tree, hf_dtls_heartbeat_message_payload_length,
tvb, offset, 2, payload_length);
offset += 2;
if (payload_length > record_length - 16 - 3) {
expert_add_info_format(pinfo, ti, &ei_dtls_heartbeat_payload_length,
"Invalid heartbeat payload length (%d)", payload_length);
/* Invalid heartbeat payload length, adjust to try decoding */
payload_length = record_length - 16 - 3;
padding_length = 16;
proto_item_append_text (ti, " (invalid, using %u to decode payload)", payload_length);
}
proto_tree_add_bytes_format(dtls_heartbeat_tree, hf_dtls_heartbeat_message_payload,
tvb, offset, payload_length,
NULL, "Payload (%u byte%s)",
payload_length,
plurality(payload_length, "", "s"));
offset += payload_length;
proto_tree_add_bytes_format(dtls_heartbeat_tree, hf_dtls_heartbeat_message_padding,
tvb, offset, padding_length,
NULL, "Padding and HMAC (%u byte%s)",
padding_length,
plurality(padding_length, "", "s"));
} else {
proto_item_set_text(tree,
"%s Record Layer: Encrypted Heartbeat",
val_to_str_const(session->version, ssl_version_short_names, "DTLS"));
proto_item_set_text(dtls_heartbeat_tree,
"Encrypted Heartbeat Message");
}
}
}
static int
dissect_dtls_hnd_hello_verify_request(ssl_common_dissect_t *hf, tvbuff_t *tvb,
packet_info *pinfo, proto_tree *tree,
guint32 offset, guint32 offset_end)
{
/*
* struct {
* ProtocolVersion server_version;
* opaque cookie<0..32>;
* } HelloVerifyRequest;
*/
guint32 cookie_length;
/* show the client version */
proto_tree_add_item(tree, dissect_dtls_hf.hf.hs_server_version, tvb,
offset, 2, ENC_BIG_ENDIAN);
offset += 2;
if (!ssl_add_vector(hf, tvb, pinfo, tree, offset, offset_end, &cookie_length,
dtls_hfs.hf_dtls_handshake_cookie_len, 0, 32)) {
return offset;
}
offset++;
if (cookie_length > 0)
{
proto_tree_add_item(tree, dtls_hfs.hf_dtls_handshake_cookie,
tvb, offset, cookie_length, ENC_NA);
offset += cookie_length;
}
return offset;
}
gint
dtls_dissect_hnd_hello_ext_use_srtp(packet_info *pinfo, tvbuff_t *tvb,
proto_tree *tree, guint32 offset,
guint32 ext_len, gboolean is_server)
{
/* From https://tools.ietf.org/html/rfc5764#section-4.1.1
*
* uint8 SRTPProtectionProfile[2];
*
* struct {
* SRTPProtectionProfiles SRTPProtectionProfiles;
* opaque srtp_mki<0..255>;
* } UseSRTPData;
*
* SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>;
*/
guint32 profiles_length, profiles_end, profile, mki_length;
if (ext_len < 2) {
/* XXX expert info, record too small */
return offset + ext_len;
}
/* SRTPProtectionProfiles list length */
proto_tree_add_item_ret_uint(tree, hf_dtls_hs_ext_use_srtp_protection_profiles_length,
tvb, offset, 2, ENC_BIG_ENDIAN, &profiles_length);
if (profiles_length > ext_len - 2) {
/* XXX expert info because length exceeds extension_data field */
profiles_length = ext_len - 2;
}
offset += 2;
/* SRTPProtectionProfiles list items */
profiles_end = offset + profiles_length;
while (offset < profiles_end) {
/* The server, if sending the use_srtp extension, MUST return a
* single chosen profile that the client has offered. We will
* use that to set up the connection.
*/
proto_tree_add_item_ret_uint(tree,
hf_dtls_hs_ext_use_srtp_protection_profile, tvb, offset, 2,
ENC_BIG_ENDIAN, &profile);
offset += 2;
}
/* MKI */
proto_tree_add_item_ret_uint(tree, hf_dtls_hs_ext_use_srtp_mki_length,
tvb, offset, 1, ENC_NA, &mki_length);
offset++;
if (mki_length > 0) {
proto_tree_add_item(tree, hf_dtls_hs_ext_use_srtp_mki,
tvb, offset, mki_length, ENC_NA);
offset += mki_length;
}
/* If we only get the Client Hello, we don't know which SRTP protection
* profile is chosen, unless only one was provided.
*/
if (is_server || profiles_length == 2) {
struct srtp_info *srtp_info = wmem_new0(wmem_file_scope(), struct srtp_info);
switch(profile) {
case SRTP_AES128_CM_HMAC_SHA1_80:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
srtp_info->auth_tag_len = 10;
break;
case SRTP_AES128_CM_HMAC_SHA1_32:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
srtp_info->auth_tag_len = 4;
break;
case SRTP_NULL_HMAC_SHA1_80:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_NULL;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
srtp_info->auth_tag_len = 10;
break;
case SRTP_NULL_HMAC_SHA1_32:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_NULL;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
srtp_info->auth_tag_len = 4;
break;
case SRTP_AEAD_AES_128_GCM:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_GMAC;
srtp_info->auth_tag_len = 16;
break;
case SRTP_AEAD_AES_256_GCM:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_GMAC;
srtp_info->auth_tag_len = 16;
break;
default:
srtp_info->encryption_algorithm = SRTP_ENC_ALG_AES_CM;
srtp_info->auth_algorithm = SRTP_AUTH_ALG_HMAC_SHA1;
srtp_info->auth_tag_len = 10;
}
srtp_info->mki_len = mki_length;
/* RFC 5764: It is RECOMMENDED that symmetric RTP be used with DTLS-SRTP.
* RTP and RTCP traffic MAY be multiplexed on a single UDP port. (RFC 5761)
*
* XXX: This creates a new RTP conversation. What it _should_ do is update
* a RTP conversation initiated by SDP in a previous frame with the
* srtp_info. Assuming we got the SDP and decrypted it if over TLS, etc.
* However, since we don't actually decrypt SRT[C]P yet, the information
* carried in the SDP about payload and media types isn't that useful.
* (Being able to have the stream refer back to both the DTLS-SRTP and
* SDP setup frame might be useful, though.)
*/
srtp_add_address(pinfo, PT_UDP, &pinfo->net_src, pinfo->srcport, pinfo->destport, "DTLS-SRTP", pinfo->num, RTP_MEDIA_AUDIO, NULL, srtp_info, NULL);
srtp_add_address(pinfo, PT_UDP, &pinfo->net_dst, pinfo->destport, pinfo->srcport, "DTLS-SRTP", pinfo->num, RTP_MEDIA_AUDIO, NULL, srtp_info, NULL);
}
return offset;
}
/*********************************************************************
*
* Support Functions
*
*********************************************************************/
/* this applies a heuristic to determine whether
* or not the data beginning at offset looks like a
* valid dtls record.
*/
static gint
looks_like_dtls(tvbuff_t *tvb, guint32 offset)
{
/* have to have a valid content type followed by a valid
* protocol version
*/
guint8 byte;
guint16 version;
/* see if the first byte is a valid content type */
byte = tvb_get_guint8(tvb, offset);
if (!ssl_is_valid_content_type(byte))
{
return 0;
}
/* now check to see if the version byte appears valid */
version = tvb_get_ntohs(tvb, offset + 1);
if (version != DTLSV1DOT0_VERSION && version != DTLSV1DOT2_VERSION &&
version != DTLSV1DOT0_OPENSSL_VERSION)
{
return 0;
}
return 1;
}
/* UAT */
#if defined(HAVE_LIBGNUTLS)
static void
dtlsdecrypt_free_cb(void* r)
{
ssldecrypt_assoc_t* h = (ssldecrypt_assoc_t*)r;
g_free(h->ipaddr);
g_free(h->port);
g_free(h->protocol);
g_free(h->keyfile);
g_free(h->password);
}
#endif
#if 0
static void
dtlsdecrypt_update_cb(void* r _U_, const char** err _U_)
{
return;
}
#endif
#if defined(HAVE_LIBGNUTLS)
static void *
dtlsdecrypt_copy_cb(void* dest, const void* orig, size_t len _U_)
{
const ssldecrypt_assoc_t* o = (const ssldecrypt_assoc_t*)orig;
ssldecrypt_assoc_t* d = (ssldecrypt_assoc_t*)dest;
d->ipaddr = g_strdup(o->ipaddr);
d->port = g_strdup(o->port);
d->protocol = g_strdup(o->protocol);
d->keyfile = g_strdup(o->keyfile);
d->password = g_strdup(o->password);
return d;
}
UAT_CSTRING_CB_DEF(sslkeylist_uats,ipaddr,ssldecrypt_assoc_t)
UAT_CSTRING_CB_DEF(sslkeylist_uats,port,ssldecrypt_assoc_t)
UAT_CSTRING_CB_DEF(sslkeylist_uats,protocol,ssldecrypt_assoc_t)
UAT_FILENAME_CB_DEF(sslkeylist_uats,keyfile,ssldecrypt_assoc_t)
UAT_CSTRING_CB_DEF(sslkeylist_uats,password,ssldecrypt_assoc_t)
static gboolean
dtlsdecrypt_uat_fld_protocol_chk_cb(void* r _U_, const char* p, guint len _U_, const void* u1 _U_, const void* u2 _U_, char** err)
{
if (!p || strlen(p) == 0u) {
// This should be removed in favor of Decode As. Make it optional.
*err = NULL;
return TRUE;
}
if (!find_dissector(p)) {
if (proto_get_id_by_filter_name(p) != -1) {
*err = ws_strdup_printf("While '%s' is a valid dissector filter name, that dissector is not configured"
" to support DTLS decryption.\n\n"
"If you need to decrypt '%s' over DTLS, please contact the Wireshark development team.", p, p);
} else {
char* ssl_str = ssl_association_info("dtls.port", "UDP");
*err = ws_strdup_printf("Could not find dissector for: '%s'\nCommonly used DTLS dissectors include:\n%s", p, ssl_str);
g_free(ssl_str);
}
return FALSE;
}
*err = NULL;
return TRUE;
}
#endif
static void
dtls_src_prompt(packet_info *pinfo, gchar *result)
{
SslPacketInfo* pi;
guint32 srcport = pinfo->srcport;
pi = (SslPacketInfo *)p_get_proto_data(wmem_file_scope(), pinfo, proto_dtls, pinfo->curr_layer_num);
if (pi != NULL)
srcport = pi->srcport;
snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "source (%u%s)", srcport, UTF8_RIGHTWARDS_ARROW);
}
static gpointer
dtls_src_value(packet_info *pinfo)
{
SslPacketInfo* pi;
pi = (SslPacketInfo *)p_get_proto_data(wmem_file_scope(), pinfo, proto_dtls, pinfo->curr_layer_num);
if (pi == NULL)
return GUINT_TO_POINTER(pinfo->srcport);
return GUINT_TO_POINTER(pi->srcport);
}
static void
dtls_dst_prompt(packet_info *pinfo, gchar *result)
{
SslPacketInfo* pi;
guint32 destport = pinfo->destport;
pi = (SslPacketInfo *)p_get_proto_data(wmem_file_scope(), pinfo, proto_dtls, pinfo->curr_layer_num);
if (pi != NULL)
destport = pi->destport;
snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "destination (%s%u)", UTF8_RIGHTWARDS_ARROW, destport);
}
static gpointer
dtls_dst_value(packet_info *pinfo)
{
SslPacketInfo* pi;
pi = (SslPacketInfo *)p_get_proto_data(wmem_file_scope(), pinfo, proto_dtls, pinfo->curr_layer_num);
if (pi == NULL)
return GUINT_TO_POINTER(pinfo->destport);
return GUINT_TO_POINTER(pi->destport);
}
static void
dtls_both_prompt(packet_info *pinfo, gchar *result)
{
SslPacketInfo* pi;
guint32 srcport = pinfo->srcport,
destport = pinfo->destport;
pi = (SslPacketInfo *)p_get_proto_data(wmem_file_scope(), pinfo, proto_dtls, pinfo->curr_layer_num);
if (pi != NULL)
{
srcport = pi->srcport;
destport = pi->destport;
}
snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "both (%u%s%u)", srcport, UTF8_LEFT_RIGHT_ARROW, destport);
}
void proto_reg_handoff_dtls(void);
/*********************************************************************
*
* Standard Wireshark Protocol Registration and housekeeping
*
*********************************************************************/
void
proto_register_dtls(void)
{
/* Setup list of header fields See Section 1.6.1 for details*/
static hf_register_info hf[] = {
{ &hf_dtls_record,
{ "Record Layer", "dtls.record",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_record_content_type,
{ "Content Type", "dtls.record.content_type",
FT_UINT8, BASE_DEC, VALS(ssl_31_content_type), 0x0,
NULL, HFILL}
},
{ &hf_dtls_record_special_type,
{ "Special Type", "dtls.record.special_type",
FT_UINT8, BASE_DEC, VALS(ssl_31_content_type), 0x0,
"Always set to value 25, actual content type is known after decryption", HFILL}
},
{ &hf_dtls_record_version,
{ "Version", "dtls.record.version",
FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0,
"Record layer version", HFILL }
},
{ &hf_dtls_record_epoch,
{ "Epoch", "dtls.record.epoch",
FT_UINT16, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_record_sequence_number,
{ "Sequence Number", "dtls.record.sequence_number",
FT_UINT64, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_record_connection_id,
{ "Connection ID", "dtls.record.connection_id",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_record_length,
{ "Length", "dtls.record.length",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Length of DTLS record data", HFILL }
},
{ &hf_dtls_record_appdata,
{ "Encrypted Application Data", "dtls.app_data",
FT_BYTES, BASE_NONE, NULL, 0x0,
"Payload is encrypted application data", HFILL }
},
{ &hf_dtls_record_appdata_proto,
{ "Application Data Protocol", "dtls.app_data_proto",
FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_record_encrypted_content,
{ "Encrypted Record Content", "dtls.enc_content",
FT_BYTES, BASE_NONE, NULL, 0x0,
"Encrypted record data", HFILL }
},
{ & hf_dtls_alert_message,
{ "Alert Message", "dtls.alert_message",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ & hf_dtls_alert_message_level,
{ "Level", "dtls.alert_message.level",
FT_UINT8, BASE_DEC, VALS(ssl_31_alert_level), 0x0,
"Alert message level", HFILL }
},
{ &hf_dtls_alert_message_description,
{ "Description", "dtls.alert_message.desc",
FT_UINT8, BASE_DEC, VALS(ssl_31_alert_description), 0x0,
"Alert message description", HFILL }
},
{ &hf_dtls_handshake_protocol,
{ "Handshake Protocol", "dtls.handshake",
FT_NONE, BASE_NONE, NULL, 0x0,
"Handshake protocol message", HFILL}
},
{ &hf_dtls_handshake_type,
{ "Handshake Type", "dtls.handshake.type",
FT_UINT8, BASE_DEC, VALS(ssl_31_handshake_type), 0x0,
"Type of handshake message", HFILL}
},
{ &hf_dtls_handshake_length,
{ "Length", "dtls.handshake.length",
FT_UINT24, BASE_DEC, NULL, 0x0,
"Length of handshake message", HFILL }
},
{ &hf_dtls_handshake_message_seq,
{ "Message Sequence", "dtls.handshake.message_seq",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Message sequence of handshake message", HFILL }
},
{ &hf_dtls_handshake_fragment_offset,
{ "Fragment Offset", "dtls.handshake.fragment_offset",
FT_UINT24, BASE_DEC, NULL, 0x0,
"Fragment offset of handshake message", HFILL }
},
{ &hf_dtls_handshake_fragment_length,
{ "Fragment Length", "dtls.handshake.fragment_length",
FT_UINT24, BASE_DEC, NULL, 0x0,
"Fragment length of handshake message", HFILL }
},
{ &dtls_hfs.hf_dtls_handshake_cookie_len,
{ "Cookie Length", "dtls.handshake.cookie_length",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Length of the cookie field", HFILL }
},
{ &dtls_hfs.hf_dtls_handshake_cookie,
{ "Cookie", "dtls.handshake.cookie",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_heartbeat_message,
{ "Heartbeat Message", "dtls.heartbeat_message",
FT_NONE, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_dtls_heartbeat_message_type,
{ "Type", "dtls.heartbeat_message.type",
FT_UINT8, BASE_DEC, VALS(tls_heartbeat_type), 0x0,
"Heartbeat message type", HFILL }
},
{ &hf_dtls_heartbeat_message_payload_length,
{ "Payload Length", "dtls.heartbeat_message.payload_length",
FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_heartbeat_message_payload,
{ "Payload Length", "dtls.heartbeat_message.payload",
FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_heartbeat_message_padding,
{ "Payload Length", "dtls.heartbeat_message.padding",
FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_fragments,
{ "Message fragments", "dtls.fragments",
FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_fragment,
{ "Message fragment", "dtls.fragment",
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_fragment_overlap,
{ "Message fragment overlap", "dtls.fragment.overlap",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_dtls_fragment_overlap_conflicts,
{ "Message fragment overlapping with conflicting data",
"dtls.fragment.overlap.conflicts",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_dtls_fragment_multiple_tails,
{ "Message has multiple tail fragments",
"dtls.fragment.multiple_tails",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_dtls_fragment_too_long_fragment,
{ "Message fragment too long", "dtls.fragment.too_long_fragment",
FT_BOOLEAN, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_dtls_fragment_error,
{ "Message defragmentation error", "dtls.fragment.error",
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_fragment_count,
{ "Message fragment count", "dtls.fragment.count",
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_reassembled_in,
{ "Reassembled in", "dtls.reassembled.in",
FT_FRAMENUM, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_reassembled_length,
{ "Reassembled DTLS length", "dtls.reassembled.length",
FT_UINT32, BASE_DEC, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_hs_ext_use_srtp_protection_profiles_length,
{ "SRTP Protection Profiles Length", "dtls.use_srtp.protection_profiles_length",
FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_hs_ext_use_srtp_protection_profile,
{ "SRTP Protection Profile", "dtls.use_srtp.protection_profile",
FT_UINT16, BASE_HEX, VALS(srtp_protection_profile_vals), 0x00, NULL, HFILL }
},
{ &hf_dtls_hs_ext_use_srtp_mki_length,
{ "MKI Length", "dtls.use_srtp.mki_length",
FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL }
},
{ &hf_dtls_hs_ext_use_srtp_mki,
{ "MKI", "dtls.use_srtp.mki",
FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }
},
SSL_COMMON_HF_LIST(dissect_dtls_hf, "dtls")
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_dtls,
&ett_dtls_record,
&ett_dtls_alert,
&ett_dtls_handshake,
&ett_dtls_heartbeat,
&ett_dtls_certs,
&ett_dtls_fragment,
&ett_dtls_fragments,
SSL_COMMON_ETT_LIST(dissect_dtls_hf)
};
static ei_register_info ei[] = {
{ &ei_dtls_handshake_fragment_length_zero, { "dtls.handshake.fragment_length.zero", PI_PROTOCOL, PI_WARN, "Zero-length fragment length for fragmented message", EXPFILL }},
{ &ei_dtls_handshake_fragment_length_too_long, { "dtls.handshake.fragment_length.too_long", PI_PROTOCOL, PI_ERROR, "Fragment length is larger than message length", EXPFILL }},
{ &ei_dtls_handshake_fragment_past_end_msg, { "dtls.handshake.fragment_past_end_msg", PI_PROTOCOL, PI_ERROR, "Fragment runs past the end of the message", EXPFILL }},
{ &ei_dtls_msg_len_diff_fragment, { "dtls.msg_len_diff_fragment", PI_PROTOCOL, PI_ERROR, "Message length differs from value in earlier fragment", EXPFILL }},
{ &ei_dtls_heartbeat_payload_length, { "dtls.heartbeat_message.payload_length.invalid", PI_MALFORMED, PI_ERROR, "Invalid heartbeat payload length", EXPFILL }},
{ &ei_dtls_cid_invalid_content_type, { "dtls.cid.content_type.invalid", PI_MALFORMED, PI_ERROR, "Invalid real content type", EXPFILL }},
#if 0
{ &ei_dtls_cid_invalid_enc_content, { "dtls.cid.enc_content.invalid", PI_MALFORMED, PI_ERROR, "Invalid encrypted content", EXPFILL }},
#endif
SSL_COMMON_EI_LIST(dissect_dtls_hf, "dtls")
};
static build_valid_func dtls_da_src_values[1] = {dtls_src_value};
static build_valid_func dtls_da_dst_values[1] = {dtls_dst_value};
static build_valid_func dtls_da_both_values[2] = {dtls_src_value, dtls_dst_value};
static decode_as_value_t dtls_da_values[3] = {{dtls_src_prompt, 1, dtls_da_src_values}, {dtls_dst_prompt, 1, dtls_da_dst_values}, {dtls_both_prompt, 2, dtls_da_both_values}};
static decode_as_t dtls_da = {"dtls", "dtls.port", 3, 2, dtls_da_values, "UDP", "port(s) as",
decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
expert_module_t* expert_dtls;
/* Register the protocol name and description */
proto_dtls = proto_register_protocol("Datagram Transport Layer Security",
"DTLS", "dtls");
dtls_associations = register_dissector_table("dtls.port", "DTLS Port", proto_dtls, FT_UINT16, BASE_DEC);
ssl_common_register_dtls_alpn_dissector_table("dtls.alpn",
"DTLS Application-Layer Protocol Negotiation (ALPN) Protocol IDs",
proto_dtls);
/* Required function calls to register the header fields and
* subtrees used */
proto_register_field_array(proto_dtls, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_dtls = expert_register_protocol(proto_dtls);
expert_register_field_array(expert_dtls, ei, array_length(ei));
{
module_t *dtls_module = prefs_register_protocol(proto_dtls, proto_reg_handoff_dtls);
#ifdef HAVE_LIBGNUTLS
static uat_field_t dtlskeylist_uats_flds[] = {
UAT_FLD_CSTRING_OTHER(sslkeylist_uats, ipaddr, "IP address", ssldecrypt_uat_fld_ip_chk_cb, "IPv4 or IPv6 address (unused)"),
UAT_FLD_CSTRING_OTHER(sslkeylist_uats, port, "Port", ssldecrypt_uat_fld_port_chk_cb, "Port Number (optional)"),
UAT_FLD_CSTRING_OTHER(sslkeylist_uats, protocol, "Protocol", dtlsdecrypt_uat_fld_protocol_chk_cb, "Application Layer Protocol (optional)"),
UAT_FLD_FILENAME_OTHER(sslkeylist_uats, keyfile, "Key File", ssldecrypt_uat_fld_fileopen_chk_cb, "Path to the keyfile."),
UAT_FLD_CSTRING_OTHER(sslkeylist_uats, password," Password (p12 file)", ssldecrypt_uat_fld_password_chk_cb, "Password"),
UAT_END_FIELDS
};
dtlsdecrypt_uat = uat_new("DTLS RSA Keylist",
sizeof(ssldecrypt_assoc_t),
"dtlsdecrypttablefile", /* filename */
TRUE, /* from_profile */
&dtlskeylist_uats, /* data_ptr */
&ndtlsdecrypt, /* numitems_ptr */
UAT_AFFECTS_DISSECTION, /* affects dissection of packets, but not set of named fields */
"ChK12ProtocolsSection", /* TODO, need revision - help */
dtlsdecrypt_copy_cb,
NULL, /* dtlsdecrypt_update_cb? */
dtlsdecrypt_free_cb,
dtls_parse_uat,
dtls_reset_uat,
dtlskeylist_uats_flds);
prefs_register_uat_preference(dtls_module, "cfg",
"RSA keys list",
"A table of RSA keys for DTLS decryption",
dtlsdecrypt_uat);
prefs_register_string_preference(dtls_module, "keys_list", "RSA keys list (deprecated)",
"Semicolon-separated list of private RSA keys used for DTLS decryption. "
"Used by versions of Wireshark prior to 1.6",
&dtls_keys_list);
#endif /* HAVE_LIBGNUTLS */
prefs_register_filename_preference(dtls_module, "debug_file", "DTLS debug file",
"redirect dtls debug to file name; leave empty to disable debug, "
"use \"" SSL_DEBUG_USE_STDERR "\" to redirect output to stderr\n",
&dtls_debug_file_name, TRUE);
prefs_register_uint_preference(dtls_module, "client_cid_length", "Client Connection ID length",
"Default client Connection ID length used when the Client Handshake message is missing",
10, &dtls_default_client_cid_length);
prefs_register_uint_preference(dtls_module, "server_cid_length", "Server Connection ID length",
"Default server Connection ID length used when the Server Handshake message is missing",
10, &dtls_default_server_cid_length);
ssl_common_register_options(dtls_module, &dtls_options, TRUE);
}
dtls_handle = register_dissector("dtls", dissect_dtls, proto_dtls);
register_init_routine(dtls_init);
register_cleanup_routine(dtls_cleanup);
reassembly_table_register (&dtls_reassembly_table, &addresses_ports_reassembly_table_functions);
register_decode_as(&dtls_da);
dtls_tap = register_tap("dtls");
ssl_debug_printf("proto_register_dtls: registered tap %s:%d\n",
"dtls", dtls_tap);
heur_subdissector_list = register_heur_dissector_list("dtls", proto_dtls);
}
/* If this dissector uses sub-dissector registration add a registration
* routine. This format is required because a script is used to find
* these routines and create the code that calls these routines.
*/
void
proto_reg_handoff_dtls(void)
{
static gboolean initialized = FALSE;
#ifdef HAVE_LIBGNUTLS
dtls_parse_uat();
dtls_parse_old_keys();
#endif
exported_pdu_tap = find_tap_id(EXPORT_PDU_TAP_NAME_LAYER_7);
if (initialized == FALSE) {
heur_dissector_add("udp", dissect_dtls_heur, "DTLS over UDP", "dtls_udp", proto_dtls, HEURISTIC_ENABLE);
heur_dissector_add("stun", dissect_dtls_heur, "DTLS over STUN", "dtls_stun", proto_dtls, HEURISTIC_DISABLE);
heur_dissector_add("classicstun", dissect_dtls_heur, "DTLS over CLASSICSTUN", "dtls_classicstun", proto_dtls, HEURISTIC_DISABLE);
dissector_add_uint("sctp.ppi", DIAMETER_DTLS_PROTOCOL_ID, dtls_handle);
}
initialized = TRUE;
}
void
dtls_dissector_add(guint port, dissector_handle_t handle)
{
ssl_association_add("dtls.port", dtls_handle, handle, port, FALSE);
}
void
dtls_dissector_delete(guint port, dissector_handle_t handle)
{
ssl_association_remove("dtls.port", dtls_handle, handle, port, FALSE);
}
/*
* Editor modelines - https://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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