50e1634f4c
so that if the start_ptr is NULL the bytes are extracted from the given TVB using the given offset and length. Replace a bunch of: proto_tree_add_bytes_format*(tree, hf, tvb, offset, length, tvb_get_ptr(tvb, offset, length), [...]) with: proto_tree_add_bytes_format*(tree, hf, tvb, offset, length, NULL, [...]) svn path=/trunk/; revision=35896
2275 lines
78 KiB
C
2275 lines
78 KiB
C
/* packet-dtls.c
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* Routines for dtls dissection
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* Copyright (c) 2006, Authesserre Samuel <sauthess@gmail.com>
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* Copyright (c) 2007, Mikael Magnusson <mikma@users.sourceforge.net>
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*
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* DTLS dissection and decryption.
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* See RFC 4347 for details about DTLS specs.
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*
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* Notes :
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* This dissector is based on TLS one (packet-ssl.c) because of the proximity of DTLS and TLS, decryption works like him with RSA key exchange.
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* It uses the sames things (file, libraries) that SSL one (gnutls, packet-ssl-utils.h) to make it easily maintenable.
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*
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* It was developped to dissect and decrypt OpenSSL v 0.9.8f DTLS implementation.
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* It is limited to this implementation while there is no complete implementation.
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*
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* Implemented :
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* - DTLS dissection
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* - DTLS decryption (openssl one)
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*
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* Todo :
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* - activate correct Mac calculation when openssl will be corrected
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* (or if an other implementation works),
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* corrected code is ready and commented in packet-ssl-utils.h file.
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* - add missings things (desegmentation, reordering... that aren't present in actual OpenSSL implementation)
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#ifdef HAVE_SYS_SOCKET_H
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#include <sys/socket.h>
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#endif
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#ifdef HAVE_WINSOCK2_H
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#include <winsock2.h>
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#endif
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#include <glib.h>
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#include <epan/conversation.h>
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#include <epan/prefs.h>
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#include <epan/asn1.h>
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#include <epan/dissectors/packet-x509af.h>
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#include <epan/emem.h>
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#include <epan/tap.h>
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#include <epan/reassemble.h>
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#ifdef NEED_INET_V6DEFS_H
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#include "wsutil/inet_v6defs.h"
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#endif
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#include "packet-ssl-utils.h"
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/* we need to remember the top tree so that subdissectors we call are created
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* at the root and not deep down inside the DTLS decode
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*/
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static proto_tree *top_tree;
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/*********************************************************************
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*
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* Protocol Constants, Variables, Data Structures
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*
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*********************************************************************/
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/* Initialize the protocol and registered fields */
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static gint dtls_tap = -1;
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static gint proto_dtls = -1;
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static gint hf_dtls_record = -1;
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static gint hf_dtls_record_content_type = -1;
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static gint hf_dtls_record_version = -1;
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static gint hf_dtls_record_epoch = -1;
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static gint hf_dtls_record_sequence_number = -1;
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static gint hf_dtls_record_length = -1;
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static gint hf_dtls_record_appdata = -1;
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static gint hf_dtls_change_cipher_spec = -1;
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static gint hf_dtls_alert_message = -1;
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static gint hf_dtls_alert_message_level = -1;
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static gint hf_dtls_alert_message_description = -1;
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static gint hf_dtls_handshake_protocol = -1;
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static gint hf_dtls_handshake_type = -1;
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static gint hf_dtls_handshake_length = -1;
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static gint hf_dtls_handshake_message_seq = -1;
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static gint hf_dtls_handshake_fragment_offset = -1;
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static gint hf_dtls_handshake_fragment_length = -1;
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static gint hf_dtls_handshake_client_version = -1;
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static gint hf_dtls_handshake_server_version = -1;
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static gint hf_dtls_handshake_random_time = -1;
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static gint hf_dtls_handshake_random_bytes = -1;
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static gint hf_dtls_handshake_cookie_len = -1;
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static gint hf_dtls_handshake_cookie = -1;
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static gint hf_dtls_handshake_cipher_suites_len = -1;
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static gint hf_dtls_handshake_cipher_suites = -1;
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static gint hf_dtls_handshake_cipher_suite = -1;
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static gint hf_dtls_handshake_session_id = -1;
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static gint hf_dtls_handshake_comp_methods_len = -1;
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static gint hf_dtls_handshake_comp_methods = -1;
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static gint hf_dtls_handshake_comp_method = -1;
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static gint hf_dtls_handshake_extensions_len = -1;
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static gint hf_dtls_handshake_extension_type = -1;
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static gint hf_dtls_handshake_extension_len = -1;
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static gint hf_dtls_handshake_extension_data = -1;
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static gint hf_dtls_handshake_certificates_len = -1;
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static gint hf_dtls_handshake_certificates = -1;
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static gint hf_dtls_handshake_certificate = -1;
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static gint hf_dtls_handshake_certificate_len = -1;
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static gint hf_dtls_handshake_cert_types_count = -1;
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static gint hf_dtls_handshake_cert_types = -1;
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static gint hf_dtls_handshake_cert_type = -1;
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static gint hf_dtls_handshake_finished = -1;
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static gint hf_dtls_handshake_md5_hash = -1;
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static gint hf_dtls_handshake_sha_hash = -1;
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static gint hf_dtls_handshake_session_id_len = -1;
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static gint hf_dtls_handshake_dnames_len = -1;
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static gint hf_dtls_handshake_dnames = -1;
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static gint hf_dtls_handshake_dname_len = -1;
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static gint hf_dtls_handshake_dname = -1;
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static gint hf_dtls_fragments = -1;
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static gint hf_dtls_fragment = -1;
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static gint hf_dtls_fragment_overlap = -1;
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static gint hf_dtls_fragment_overlap_conflicts = -1;
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static gint hf_dtls_fragment_multiple_tails = -1;
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static gint hf_dtls_fragment_too_long_fragment = -1;
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static gint hf_dtls_fragment_error = -1;
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static gint hf_dtls_fragment_count = -1;
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static gint hf_dtls_reassembled_in = -1;
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static gint hf_dtls_reassembled_length = -1;
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/* Initialize the subtree pointers */
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static gint ett_dtls = -1;
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static gint ett_dtls_record = -1;
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static gint ett_dtls_alert = -1;
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static gint ett_dtls_handshake = -1;
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static gint ett_dtls_cipher_suites = -1;
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static gint ett_dtls_comp_methods = -1;
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static gint ett_dtls_extension = -1;
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static gint ett_dtls_certs = -1;
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static gint ett_dtls_cert_types = -1;
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static gint ett_dtls_dnames = -1;
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static gint ett_dtls_fragment = -1;
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static gint ett_dtls_fragments = -1;
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static GHashTable *dtls_session_hash = NULL;
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static GHashTable *dtls_key_hash = NULL;
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static GHashTable *dtls_fragment_table = NULL;
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static GTree* dtls_associations = NULL;
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static dissector_handle_t dtls_handle = NULL;
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static StringInfo dtls_compressed_data = {NULL, 0};
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static StringInfo dtls_decrypted_data = {NULL, 0};
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static gint dtls_decrypted_data_avail = 0;
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static gchar* dtls_keys_list = NULL;
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#ifdef HAVE_LIBGNUTLS
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static gchar* dtls_debug_file_name = NULL;
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#endif
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static const fragment_items dtls_frag_items = {
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/* Fragment subtrees */
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&ett_dtls_fragment,
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&ett_dtls_fragments,
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/* Fragment fields */
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&hf_dtls_fragments,
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&hf_dtls_fragment,
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&hf_dtls_fragment_overlap,
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&hf_dtls_fragment_overlap_conflicts,
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&hf_dtls_fragment_multiple_tails,
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&hf_dtls_fragment_too_long_fragment,
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&hf_dtls_fragment_error,
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&hf_dtls_fragment_count,
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/* Reassembled in field */
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&hf_dtls_reassembled_in,
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/* Reassembled length field */
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&hf_dtls_reassembled_length,
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/* Tag */
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"Message fragments"
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};
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/* initialize/reset per capture state data (dtls sessions cache) */
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static void
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dtls_init(void)
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{
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ssl_common_init(&dtls_session_hash, &dtls_decrypted_data, &dtls_compressed_data);
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fragment_table_init (&dtls_fragment_table);
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}
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/* parse dtls related preferences (private keys and ports association strings) */
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static void
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dtls_parse(void)
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{
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ep_stack_t tmp_stack;
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SslAssociation *tmp_assoc;
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if (dtls_key_hash)
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{
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g_hash_table_foreach(dtls_key_hash, ssl_private_key_free, NULL);
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g_hash_table_destroy(dtls_key_hash);
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}
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/* remove only associations created from key list */
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tmp_stack = ep_stack_new();
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g_tree_foreach(dtls_associations, ssl_assoc_from_key_list, tmp_stack);
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while ((tmp_assoc = ep_stack_pop(tmp_stack)) != NULL) {
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ssl_association_remove(dtls_associations, tmp_assoc);
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}
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/* parse private keys string, load available keys and put them in key hash*/
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dtls_key_hash = g_hash_table_new(ssl_private_key_hash, ssl_private_key_equal);
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if (dtls_keys_list && (dtls_keys_list[0] != 0))
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{
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ssl_parse_key_list(dtls_keys_list,dtls_key_hash,dtls_associations,dtls_handle,FALSE);
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}
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ssl_set_debug(dtls_debug_file_name);
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dissector_add_handle("sctp.port", dtls_handle);
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dissector_add_handle("udp.port", dtls_handle);
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}
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/*
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* DTLS Dissection Routines
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*
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*/
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/* record layer dissector */
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static gint dissect_dtls_record(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree, guint32 offset,
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guint *conv_version,
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SslDecryptSession *conv_data);
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/* change cipher spec dissector */
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static void dissect_dtls_change_cipher_spec(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset,
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guint *conv_version, guint8 content_type);
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/* alert message dissector */
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static void dissect_dtls_alert(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree, guint32 offset,
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guint *conv_version);
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/* handshake protocol dissector */
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static void dissect_dtls_handshake(tvbuff_t *tvb, packet_info *pinfo,
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proto_tree *tree, guint32 offset,
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guint32 record_length,
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guint *conv_version,
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SslDecryptSession *conv_data, guint8 content_type);
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|
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static void dissect_dtls_hnd_cli_hello(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset, guint32 length,
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SslDecryptSession* ssl);
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static void dissect_dtls_hnd_hello_verify_request(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset,
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SslDecryptSession* ssl);
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static void dissect_dtls_hnd_srv_hello(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset, guint32 length,
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SslDecryptSession* ssl);
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|
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static void dissect_dtls_hnd_cert(tvbuff_t *tvb,
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proto_tree *tree, guint32 offset, packet_info *pinfo);
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static void dissect_dtls_hnd_cert_req(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset);
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static void dissect_dtls_hnd_finished(tvbuff_t *tvb,
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proto_tree *tree,
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guint32 offset,
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guint* conv_version);
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|
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/*
|
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* Support Functions
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*
|
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*/
|
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/*static void ssl_set_conv_version(packet_info *pinfo, guint version);*/
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static gint dtls_is_valid_handshake_type(guint8 type);
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static gint dtls_is_authoritative_version_message(guint8 content_type,
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guint8 next_byte);
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static gint looks_like_dtls(tvbuff_t *tvb, guint32 offset);
|
|
|
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/*********************************************************************
|
|
*
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* Main dissector
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*
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*********************************************************************/
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/*
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* Code to actually dissect the packets
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*/
|
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static void
|
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dissect_dtls(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
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{
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|
|
|
conversation_t *conversation;
|
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void *conv_data;
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proto_item *ti;
|
|
proto_tree *dtls_tree;
|
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guint32 offset;
|
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gboolean first_record_in_frame;
|
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SslDecryptSession* ssl_session;
|
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guint* conv_version;
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ti = NULL;
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dtls_tree = NULL;
|
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offset = 0;
|
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first_record_in_frame = TRUE;
|
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ssl_session = NULL;
|
|
top_tree=tree;
|
|
|
|
/* Track the version using conversations allows
|
|
* us to more frequently set the protocol column properly
|
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* for continuation data frames.
|
|
*
|
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* Also: We use the copy in conv_version as our cached copy,
|
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* so that we don't have to search the conversation
|
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* table every time we want the version; when setting
|
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* the conv_version, must set the copy in the conversation
|
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* in addition to conv_version
|
|
*/
|
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conversation = find_or_create_conversation(pinfo);
|
|
conv_data = conversation_get_proto_data(conversation, proto_dtls);
|
|
|
|
/* manage dtls decryption data */
|
|
/*get a valid ssl session pointer*/
|
|
if (conv_data != NULL)
|
|
ssl_session = conv_data;
|
|
else {
|
|
SslService dummy;
|
|
|
|
ssl_session = se_alloc0(sizeof(SslDecryptSession));
|
|
ssl_session_init(ssl_session);
|
|
ssl_session->version = SSL_VER_UNKNOWN;
|
|
conversation_add_proto_data(conversation, proto_dtls, ssl_session);
|
|
|
|
/* we need to know witch side of conversation is speaking */
|
|
if (ssl_packet_from_server(ssl_session, dtls_associations, pinfo)) {
|
|
dummy.addr = pinfo->src;
|
|
dummy.port = pinfo->srcport;
|
|
}
|
|
else {
|
|
dummy.addr = pinfo->dst;
|
|
dummy.port = pinfo->destport;
|
|
}
|
|
ssl_debug_printf("dissect_dtls server %s:%d\n",
|
|
ep_address_to_str(&dummy.addr),dummy.port);
|
|
|
|
/* try to retrive private key for this service. Do it now 'cause pinfo
|
|
* is not always available
|
|
* Note that with HAVE_LIBGNUTLS undefined private_key is allways 0
|
|
* and thus decryption never engaged*/
|
|
ssl_session->private_key = g_hash_table_lookup(dtls_key_hash, &dummy);
|
|
if (!ssl_session->private_key)
|
|
ssl_debug_printf("dissect_dtls can't find private key for this server!\n");
|
|
}
|
|
conv_version= & ssl_session->version;
|
|
|
|
/* try decryption only the first time we see this packet
|
|
* (to keep cipher synchronized)and only if we have
|
|
* the server private key*/
|
|
if (!ssl_session->private_key || pinfo->fd->flags.visited)
|
|
ssl_session = NULL;
|
|
|
|
/* Initialize the protocol column; we'll set it later when we
|
|
* figure out what flavor of DTLS it is (actually only one
|
|
version exists). */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
|
|
|
|
/* clear the the info column */
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
|
|
/* Create display subtree for SSL as a whole */
|
|
if (tree)
|
|
{
|
|
ti = proto_tree_add_item(tree, proto_dtls, tvb, 0, -1, FALSE);
|
|
dtls_tree = proto_item_add_subtree(ti, ett_dtls);
|
|
}
|
|
|
|
/* iterate through the records in this tvbuff */
|
|
while (tvb_reported_length_remaining(tvb, offset) != 0)
|
|
{
|
|
/* on second and subsequent records per frame
|
|
* add a delimiter on info column
|
|
*/
|
|
if (!first_record_in_frame)
|
|
{
|
|
col_append_str(pinfo->cinfo, COL_INFO, ", ");
|
|
}
|
|
|
|
/* first try to dispatch off the cached version
|
|
* known to be associated with the conversation
|
|
*/
|
|
switch(*conv_version) {
|
|
case SSL_VER_DTLS:
|
|
offset = dissect_dtls_record(tvb, pinfo, dtls_tree,
|
|
offset, conv_version,
|
|
ssl_session);
|
|
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, conv_version,
|
|
ssl_session);
|
|
}
|
|
else
|
|
{
|
|
/* looks like something unknown, so lump into
|
|
* continuation data
|
|
*/
|
|
offset = tvb_length(tvb);
|
|
col_append_str(pinfo->cinfo, COL_INFO,
|
|
"Continuation Data");
|
|
|
|
/* Set the protocol column */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* set up for next record in frame, if any */
|
|
first_record_in_frame = FALSE;
|
|
}
|
|
|
|
tap_queue_packet(dtls_tap, pinfo, NULL);
|
|
}
|
|
|
|
static gint
|
|
decrypt_dtls_record(tvbuff_t *tvb, packet_info *pinfo, guint32 offset,
|
|
guint32 record_length, guint8 content_type, SslDecryptSession* ssl,
|
|
gboolean save_plaintext)
|
|
{
|
|
gint ret;
|
|
gint direction;
|
|
SslDecoder* decoder;
|
|
ret = 0;
|
|
|
|
/* if we can decrypt and decryption have success
|
|
* add decrypted data to this packet info */
|
|
ssl_debug_printf("decrypt_dtls_record: app_data len %d, ssl state %X\n",
|
|
record_length, ssl->state);
|
|
if (!(ssl->state & SSL_HAVE_SESSION_KEY)) {
|
|
ssl_debug_printf("decrypt_dtls_record: no session key\n");
|
|
return ret;
|
|
}
|
|
|
|
/* retrive decoder for this packet direction */
|
|
if ((direction = ssl_packet_from_server(ssl, 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;
|
|
}
|
|
|
|
/* 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 = 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_decrypt_record(ssl, decoder,
|
|
content_type, tvb_get_ptr(tvb, offset, record_length),
|
|
record_length, &dtls_compressed_data, &dtls_decrypted_data, &dtls_decrypted_data_avail) == 0)
|
|
ret = 1;
|
|
|
|
if (ret && save_plaintext) {
|
|
ssl_add_data_info(proto_dtls, pinfo, dtls_decrypted_data.data, dtls_decrypted_data_avail, TVB_RAW_OFFSET(tvb)+offset, 0);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*********************************************************************
|
|
*
|
|
* DTLS Dissection Routines
|
|
*
|
|
*********************************************************************/
|
|
static gint
|
|
dissect_dtls_record(tvbuff_t *tvb, packet_info *pinfo,
|
|
proto_tree *tree, guint32 offset,
|
|
guint *conv_version,
|
|
SslDecryptSession* 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;
|
|
*/
|
|
guint32 record_length;
|
|
guint16 version;
|
|
guint16 epoch;
|
|
gdouble sequence_number;
|
|
gint64 sequence_number_temp;
|
|
guint8 content_type;
|
|
guint8 next_byte;
|
|
proto_tree *ti;
|
|
proto_tree *dtls_record_tree;
|
|
guint32 available_bytes;
|
|
SslAssociation* association;
|
|
SslDataInfo *appl_data;
|
|
ti = NULL;
|
|
dtls_record_tree = NULL;
|
|
available_bytes = tvb_length_remaining(tvb, offset);
|
|
|
|
/*
|
|
* 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_ntohl(tvb, offset + 7);
|
|
sequence_number_temp=tvb_get_ntohs(tvb, offset + 5);
|
|
sequence_number_temp=sequence_number_temp<<32;
|
|
sequence_number+=sequence_number_temp;
|
|
record_length = tvb_get_ntohs(tvb, offset + 11);
|
|
|
|
if(ssl){
|
|
if(ssl_packet_from_server(ssl, dtls_associations, pinfo)){
|
|
if (ssl->server) {
|
|
ssl->server->seq=(guint32)sequence_number;
|
|
ssl->server->epoch=epoch;
|
|
}
|
|
}
|
|
else{
|
|
if (ssl->client) {
|
|
ssl->client->seq=(guint32)sequence_number;
|
|
ssl->client->epoch=epoch;
|
|
}
|
|
}
|
|
}
|
|
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_str(pinfo->cinfo, COL_INFO, "Continuation Data");
|
|
|
|
/* Set the protocol column */
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DTLS");
|
|
return offset + 13 + record_length;
|
|
}
|
|
|
|
/*
|
|
* If GUI, fill in record layer part of tree
|
|
*/
|
|
|
|
if (tree)
|
|
{
|
|
/* add the record layer subtree header */
|
|
tvb_ensure_bytes_exist(tvb, offset, 13 + record_length);
|
|
ti = proto_tree_add_item(tree, hf_dtls_record, tvb,
|
|
offset, 13 + record_length, 0);
|
|
dtls_record_tree = proto_item_add_subtree(ti, ett_dtls_record);
|
|
}
|
|
|
|
if (dtls_record_tree)
|
|
{
|
|
|
|
/* show the one-byte content type */
|
|
proto_tree_add_item(dtls_record_tree, hf_dtls_record_content_type,
|
|
tvb, offset, 1, FALSE);
|
|
offset++;
|
|
|
|
/* add the version */
|
|
proto_tree_add_item(dtls_record_tree, hf_dtls_record_version, tvb,
|
|
offset, 2, FALSE);
|
|
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_double(dtls_record_tree, hf_dtls_record_sequence_number, tvb, offset, 6, sequence_number);
|
|
|
|
offset += 6;
|
|
|
|
/* add the length */
|
|
proto_tree_add_uint(dtls_record_tree, hf_dtls_record_length, tvb,
|
|
offset, 2, record_length);
|
|
offset += 2; /* move past length field itself */
|
|
|
|
}
|
|
else
|
|
{
|
|
/* if no GUI tree, then just skip over those fields */
|
|
offset += 13;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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 to conversation
|
|
* structure and print the column version
|
|
*/
|
|
next_byte = tvb_get_guint8(tvb, offset);
|
|
if (*conv_version == SSL_VER_UNKNOWN
|
|
&& dtls_is_authoritative_version_message(content_type, next_byte))
|
|
{
|
|
if (version == DTLSV1DOT0_VERSION ||
|
|
version == DTLSV1DOT0_VERSION_NOT)
|
|
{
|
|
|
|
*conv_version = SSL_VER_DTLS;
|
|
if (ssl) {
|
|
ssl->version_netorder = version;
|
|
ssl->state |= SSL_VERSION;
|
|
}
|
|
/*ssl_set_conv_version(pinfo, ssl->version);*/
|
|
}
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
{
|
|
if (version == DTLSV1DOT0_VERSION)
|
|
{
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL,
|
|
val_to_str_const(SSL_VER_DTLS, ssl_version_short_names, "SSL"));
|
|
}
|
|
else
|
|
{
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL,"DTLS");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* now dissect the next layer
|
|
*/
|
|
ssl_debug_printf("dissect_dtls_record: content_type %d\n",content_type);
|
|
|
|
/* PAOLO try to decrypt each record (we must keep ciphers "in sync")
|
|
* store plain text only for app data */
|
|
|
|
switch (content_type) {
|
|
case SSL_ID_CHG_CIPHER_SPEC:
|
|
col_append_str(pinfo->cinfo, COL_INFO, "Change Cipher Spec");
|
|
dissect_dtls_change_cipher_spec(tvb, dtls_record_tree,
|
|
offset, conv_version, content_type);
|
|
break;
|
|
case SSL_ID_ALERT:
|
|
{
|
|
tvbuff_t* decrypted;
|
|
decrypted = 0;
|
|
if (ssl&&decrypt_dtls_record(tvb, pinfo, offset,
|
|
record_length, content_type, ssl, FALSE))
|
|
ssl_add_record_info(proto_dtls, pinfo, dtls_decrypted_data.data,
|
|
dtls_decrypted_data_avail, offset);
|
|
|
|
/* try to retrive and use decrypted alert record, if any. */
|
|
decrypted = ssl_get_record_info(proto_dtls, pinfo, offset);
|
|
if (decrypted)
|
|
dissect_dtls_alert(decrypted, pinfo, dtls_record_tree, 0,
|
|
conv_version);
|
|
else
|
|
dissect_dtls_alert(tvb, pinfo, dtls_record_tree, offset,
|
|
conv_version);
|
|
break;
|
|
}
|
|
case SSL_ID_HANDSHAKE:
|
|
{
|
|
tvbuff_t* decrypted;
|
|
decrypted = 0;
|
|
/* try to decrypt handshake record, if possible. Store decrypted
|
|
* record for later usage. The offset is used as 'key' to itentify
|
|
* this record into the packet (we can have multiple handshake records
|
|
* in the same frame) */
|
|
if (ssl && decrypt_dtls_record(tvb, pinfo, offset,
|
|
record_length, content_type, ssl, FALSE))
|
|
ssl_add_record_info(proto_dtls, pinfo, dtls_decrypted_data.data,
|
|
dtls_decrypted_data_avail, offset);
|
|
|
|
/* try to retrive and use decrypted handshake record, if any. */
|
|
decrypted = ssl_get_record_info(proto_dtls, pinfo, offset);
|
|
if (decrypted)
|
|
dissect_dtls_handshake(decrypted, pinfo, dtls_record_tree, 0,
|
|
decrypted->length, conv_version, ssl, content_type);
|
|
else
|
|
dissect_dtls_handshake(tvb, pinfo, dtls_record_tree, offset,
|
|
record_length, conv_version, ssl, content_type);
|
|
break;
|
|
}
|
|
case SSL_ID_APP_DATA:
|
|
if (ssl)
|
|
decrypt_dtls_record(tvb, pinfo, offset,
|
|
record_length, content_type, ssl, TRUE);
|
|
|
|
/* show on info colum what we are decoding */
|
|
col_append_str(pinfo->cinfo, COL_INFO, "Application Data");
|
|
|
|
if (!dtls_record_tree)
|
|
break;
|
|
|
|
/* we need dissector information when the selected packet is shown.
|
|
* ssl session pointer is NULL at that time, so we can't access
|
|
* info cached there*/
|
|
association = ssl_association_find(dtls_associations, pinfo->srcport, pinfo->ptype == PT_TCP);
|
|
association = association ? association: ssl_association_find(dtls_associations, pinfo->destport, pinfo->ptype == PT_TCP);
|
|
|
|
proto_item_set_text(dtls_record_tree,
|
|
"%s Record Layer: %s Protocol: %s",
|
|
val_to_str_const(*conv_version, ssl_version_short_names, "SSL"),
|
|
val_to_str(content_type, ssl_31_content_type, "unknown"),
|
|
association?association->info:"Application Data");
|
|
|
|
proto_tree_add_item(dtls_record_tree, hf_dtls_record_appdata, tvb,
|
|
offset, record_length, 0);
|
|
|
|
/* show decrypted data info, if available */
|
|
appl_data = ssl_get_data_info(proto_dtls, pinfo, TVB_RAW_OFFSET(tvb)+offset);
|
|
if (appl_data && (appl_data->plain_data.data_len > 0))
|
|
{
|
|
tvbuff_t *next_tvb;
|
|
/* try to dissect decrypted data*/
|
|
ssl_debug_printf("dissect_dtls_record decrypted len %d\n",
|
|
appl_data->plain_data.data_len);
|
|
|
|
/* create a new TVB structure for desegmented data */
|
|
next_tvb = tvb_new_child_real_data(tvb, appl_data->plain_data.data, appl_data->plain_data.data_len, appl_data->plain_data.data_len);
|
|
|
|
add_new_data_source(pinfo, next_tvb, "Decrypted DTLS data");
|
|
|
|
/* find out a dissector using server port*/
|
|
if (association && association->handle) {
|
|
ssl_debug_printf("dissect_dtls_record found association %p\n", (void *)association);
|
|
ssl_print_text_data("decrypted app data",appl_data->plain_data.data, appl_data->plain_data.data_len);
|
|
|
|
call_dissector(association->handle, next_tvb, pinfo, top_tree);
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
/* shouldn't get here since we check above for valid types */
|
|
col_append_str(pinfo->cinfo, COL_INFO, "Bad DTLS Content Type");
|
|
break;
|
|
}
|
|
offset += record_length; /* skip to end of record */
|
|
|
|
return offset;
|
|
}
|
|
|
|
/* dissects the change cipher spec procotol, filling in the tree */
|
|
static void
|
|
dissect_dtls_change_cipher_spec(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset,
|
|
guint* conv_version, guint8 content_type)
|
|
{
|
|
/*
|
|
* struct {
|
|
* enum { change_cipher_spec(1), (255) } type;
|
|
* } ChangeCipherSpec;
|
|
*
|
|
*/
|
|
if (tree)
|
|
{
|
|
proto_item_set_text(tree,
|
|
"%s Record Layer: %s Protocol: Change Cipher Spec",
|
|
val_to_str_const(*conv_version, ssl_version_short_names, "SSL"),
|
|
val_to_str(content_type, ssl_31_content_type, "unknown"));
|
|
proto_tree_add_item(tree, hf_dtls_change_cipher_spec, tvb,
|
|
offset++, 1, FALSE);
|
|
}
|
|
}
|
|
|
|
/* dissects the alert message, filling in the tree */
|
|
static void
|
|
dissect_dtls_alert(tvbuff_t *tvb, packet_info *pinfo,
|
|
proto_tree *tree, guint32 offset,
|
|
guint* conv_version)
|
|
{
|
|
/* struct {
|
|
* AlertLevel level;
|
|
* AlertDescription description;
|
|
* } Alert;
|
|
*/
|
|
proto_tree *ti;
|
|
proto_tree *ssl_alert_tree;
|
|
const gchar *level;
|
|
const gchar *desc;
|
|
guint8 byte;
|
|
ssl_alert_tree = NULL;
|
|
|
|
if (tree)
|
|
{
|
|
ti = proto_tree_add_item(tree, hf_dtls_alert_message, tvb,
|
|
offset, 2, 0);
|
|
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 = match_strval(byte, ssl_31_alert_level);
|
|
|
|
byte = tvb_get_guint8(tvb, offset+1); /* grab the desc byte */
|
|
desc = match_strval(byte, ssl_31_alert_description);
|
|
|
|
/* now set the text in the record layer line */
|
|
if (level && desc)
|
|
{
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_append_fstr(pinfo->cinfo, COL_INFO,
|
|
"Alert (Level: %s, Description: %s)",
|
|
level, desc);
|
|
}
|
|
else
|
|
{
|
|
col_append_str(pinfo->cinfo, COL_INFO, "Encrypted Alert");
|
|
}
|
|
|
|
if (tree)
|
|
{
|
|
if (level && desc)
|
|
{
|
|
proto_item_set_text(tree, "%s Record Layer: Alert "
|
|
"(Level: %s, Description: %s)",
|
|
val_to_str_const(*conv_version, ssl_version_short_names, "SSL"),
|
|
level, desc);
|
|
proto_tree_add_item(ssl_alert_tree, hf_dtls_alert_message_level,
|
|
tvb, offset++, 1, FALSE);
|
|
|
|
proto_tree_add_item(ssl_alert_tree, hf_dtls_alert_message_description,
|
|
tvb, offset++, 1, FALSE);
|
|
}
|
|
else
|
|
{
|
|
proto_item_set_text(tree,
|
|
"%s Record Layer: Encrypted Alert",
|
|
val_to_str_const(*conv_version, ssl_version_short_names, "SSL"));
|
|
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, guint *conv_version,
|
|
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;
|
|
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;
|
|
ti = NULL;
|
|
ssl_hand_tree = NULL;
|
|
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_data *frag_msg = NULL;
|
|
tvbuff_t *new_tvb = NULL;
|
|
const gchar *frag_str = NULL;
|
|
gboolean fragmented;
|
|
|
|
msg_type = tvb_get_guint8(tvb, offset);
|
|
msg_type_str = match_strval(msg_type, ssl_31_handshake_type);
|
|
length = tvb_get_ntoh24(tvb, offset + 1);
|
|
message_seq = tvb_get_ntohs(tvb,offset + 4);
|
|
fragment_offset = tvb_get_ntoh24(tvb, offset + 6);
|
|
fragment_length = tvb_get_ntoh24(tvb, offset + 9);
|
|
fragmented = fragment_length != length;
|
|
|
|
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;
|
|
}
|
|
|
|
/* on second and later iterations, add comma to info col */
|
|
if (!first_iteration)
|
|
{
|
|
col_append_str(pinfo->cinfo, COL_INFO, ", ");
|
|
}
|
|
|
|
/*
|
|
* Update our info string
|
|
*/
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_append_str(pinfo->cinfo, COL_INFO, (msg_type_str != NULL)
|
|
? msg_type_str : "Encrypted Handshake Message");
|
|
|
|
/* Handle fragments of known message type */
|
|
if (fragmented)
|
|
{
|
|
gboolean frag_hand;
|
|
|
|
switch (msg_type) {
|
|
case SSL_HND_HELLO_REQUEST:
|
|
case SSL_HND_CLIENT_HELLO:
|
|
case SSL_HND_HELLO_VERIFY_REQUEST:
|
|
case SSL_HND_SERVER_HELLO:
|
|
case SSL_HND_CERTIFICATE:
|
|
case SSL_HND_SERVER_KEY_EXCHG:
|
|
case SSL_HND_CERT_REQUEST:
|
|
case SSL_HND_SVR_HELLO_DONE:
|
|
case SSL_HND_CERT_VERIFY:
|
|
case SSL_HND_CLIENT_KEY_EXCHG:
|
|
case SSL_HND_FINISHED:
|
|
frag_hand = TRUE;
|
|
break;
|
|
default:
|
|
/* Ignore encrypted handshake messages */
|
|
frag_hand = FALSE;
|
|
break;
|
|
}
|
|
|
|
if (frag_hand) {
|
|
/* Fragmented handshake message */
|
|
pinfo->fragmented = TRUE;
|
|
|
|
/* Don't pass the reassembly code data that doesn't exist */
|
|
tvb_ensure_bytes_exist(tvb, fragment_offset, fragment_length);
|
|
|
|
frag_msg = fragment_add(tvb, offset+12, pinfo, message_seq,
|
|
dtls_fragment_table,
|
|
fragment_offset, fragment_length, TRUE);
|
|
fragment_set_tot_len(pinfo, message_seq, dtls_fragment_table,
|
|
length);
|
|
|
|
if (frag_msg && (fragment_length + fragment_offset) == length)
|
|
{
|
|
/* Reassembled */
|
|
new_tvb = process_reassembled_data(tvb, offset+12, pinfo,
|
|
"Reassembled DTLS",
|
|
frag_msg,
|
|
&dtls_frag_items,
|
|
NULL, tree);
|
|
frag_str = " (Reassembled)";
|
|
}
|
|
else
|
|
{
|
|
frag_str = " (Fragment)";
|
|
}
|
|
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
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(*conv_version, ssl_version_short_names, "SSL"),
|
|
val_to_str(content_type, ssl_31_content_type, "unknown"),
|
|
(msg_type_str!=NULL) ? msg_type_str :
|
|
"Encrypted Handshake Message",
|
|
(frag_str!=NULL) ? frag_str : "");
|
|
}
|
|
else
|
|
{
|
|
proto_item_set_text(tree, "%s Record Layer: %s Protocol: %s%s",
|
|
val_to_str_const(*conv_version, ssl_version_short_names, "SSL"),
|
|
val_to_str(content_type, ssl_31_content_type, "unknown"),
|
|
"Multiple Handshake Messages",
|
|
(frag_str!=NULL) ? frag_str : "");
|
|
}
|
|
|
|
/* add a subtree for the handshake protocol */
|
|
ti = proto_tree_add_item(tree, hf_dtls_handshake_protocol, tvb,
|
|
offset, fragment_length + 12, 0);
|
|
ssl_hand_tree = proto_item_add_subtree(ti, ett_dtls_handshake);
|
|
|
|
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 != NULL) ? msg_type_str :
|
|
"Encrypted Handshake Message",
|
|
(frag_str!=NULL) ? frag_str : "");
|
|
}
|
|
}
|
|
|
|
/* if we don't have a valid handshake type, just quit dissecting */
|
|
if (!msg_type_str)
|
|
return;
|
|
|
|
/* if we are doing ssl decryption we must dissect some requests type */
|
|
if (ssl_hand_tree || ssl)
|
|
{
|
|
tvbuff_t *sub_tvb = NULL;
|
|
|
|
/* add nodes for the message type and message length */
|
|
if (ssl_hand_tree)
|
|
proto_tree_add_item(ssl_hand_tree, hf_dtls_handshake_type,
|
|
tvb, offset, 1, msg_type);
|
|
offset++;
|
|
if (ssl_hand_tree)
|
|
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_length,
|
|
tvb, offset, 3, length);
|
|
offset += 3;
|
|
|
|
if (ssl_hand_tree)
|
|
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_message_seq,
|
|
tvb, offset, 2, message_seq);
|
|
offset += 2;
|
|
if (ssl_hand_tree)
|
|
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_fragment_offset,
|
|
tvb, offset, 3, fragment_offset);
|
|
offset += 3;
|
|
if (ssl_hand_tree)
|
|
proto_tree_add_uint(ssl_hand_tree, hf_dtls_handshake_fragment_length,
|
|
tvb, offset, 3, fragment_length);
|
|
offset += 3;
|
|
|
|
if (fragmented && !new_tvb)
|
|
{
|
|
/* Skip fragmented messages not reassembled yet */
|
|
continue;
|
|
}
|
|
|
|
if (new_tvb)
|
|
{
|
|
sub_tvb = new_tvb;
|
|
}
|
|
else
|
|
{
|
|
sub_tvb = tvb_new_subset(tvb, offset, fragment_length,
|
|
fragment_length);
|
|
}
|
|
|
|
/* now dissect the handshake message, if necessary */
|
|
switch (msg_type) {
|
|
case SSL_HND_HELLO_REQUEST:
|
|
/* hello_request has no fields, so nothing to do! */
|
|
break;
|
|
|
|
case SSL_HND_CLIENT_HELLO:
|
|
dissect_dtls_hnd_cli_hello(sub_tvb, ssl_hand_tree, 0, length, ssl);
|
|
break;
|
|
|
|
case SSL_HND_HELLO_VERIFY_REQUEST:
|
|
dissect_dtls_hnd_hello_verify_request(sub_tvb, ssl_hand_tree, 0, ssl);
|
|
break;
|
|
|
|
case SSL_HND_SERVER_HELLO:
|
|
dissect_dtls_hnd_srv_hello(sub_tvb, ssl_hand_tree, 0, length, ssl);
|
|
break;
|
|
|
|
case SSL_HND_CERTIFICATE:
|
|
dissect_dtls_hnd_cert(sub_tvb, ssl_hand_tree, 0, pinfo);
|
|
break;
|
|
|
|
case SSL_HND_SERVER_KEY_EXCHG:
|
|
/* unimplemented */
|
|
break;
|
|
|
|
case SSL_HND_CERT_REQUEST:
|
|
dissect_dtls_hnd_cert_req(sub_tvb, ssl_hand_tree, 0);
|
|
break;
|
|
|
|
case SSL_HND_SVR_HELLO_DONE:
|
|
/* server_hello_done has no fields, so nothing to do! */
|
|
break;
|
|
|
|
case SSL_HND_CERT_VERIFY:
|
|
/* unimplemented */
|
|
break;
|
|
|
|
case SSL_HND_CLIENT_KEY_EXCHG:
|
|
{
|
|
/* here we can have all the data to build session key */
|
|
StringInfo encrypted_pre_master;
|
|
gint ret;
|
|
guint encrlen = length, skip;
|
|
skip = 0;
|
|
|
|
if (!ssl)
|
|
break;
|
|
|
|
/* check for required session data */
|
|
ssl_debug_printf("dissect_dtls_handshake found SSL_HND_CLIENT_KEY_EXCHG, state %X\n",
|
|
ssl->state);
|
|
if ((ssl->state & (SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION)) !=
|
|
(SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION)) {
|
|
ssl_debug_printf("dissect_dtls_handshake not enough data to generate key (required state %X)\n",
|
|
(SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION));
|
|
break;
|
|
}
|
|
|
|
encrypted_pre_master.data = se_alloc(encrlen);
|
|
encrypted_pre_master.data_len = encrlen;
|
|
tvb_memcpy(tvb, encrypted_pre_master.data, offset+skip, encrlen);
|
|
|
|
if (!ssl->private_key) {
|
|
ssl_debug_printf("dissect_dtls_handshake can't find private key\n");
|
|
break;
|
|
}
|
|
|
|
/* go with ssl key processessing; encrypted_pre_master
|
|
* will be used for master secret store*/
|
|
ret = ssl_decrypt_pre_master_secret(ssl, &encrypted_pre_master, ssl->private_key);
|
|
if (ret < 0) {
|
|
ssl_debug_printf("dissect_dtls_handshake can't decrypt pre master secret\n");
|
|
break;
|
|
}
|
|
if (ssl_generate_keyring_material(ssl)<0) {
|
|
ssl_debug_printf("dissect_dtls_handshake can't generate keyring material\n");
|
|
break;
|
|
}
|
|
ssl->state |= SSL_HAVE_SESSION_KEY;
|
|
ssl_save_session(ssl, dtls_session_hash);
|
|
ssl_debug_printf("dissect_dtls_handshake session keys successfully generated\n");
|
|
}
|
|
break;
|
|
|
|
case SSL_HND_FINISHED:
|
|
dissect_dtls_hnd_finished(sub_tvb, ssl_hand_tree,
|
|
0, conv_version);
|
|
break;
|
|
}
|
|
|
|
}
|
|
else{
|
|
offset += 12; /* skip the handshake header when handshake is not processed*/
|
|
}
|
|
}
|
|
}
|
|
|
|
static gint
|
|
dissect_dtls_hnd_hello_common(tvbuff_t *tvb, proto_tree *tree,
|
|
guint32 offset, SslDecryptSession* ssl, gint from_server)
|
|
{
|
|
/* show the client's random challenge */
|
|
nstime_t gmt_unix_time;
|
|
guint8 session_id_length;
|
|
session_id_length = 0;
|
|
if (ssl)
|
|
{
|
|
/* get proper peer information*/
|
|
StringInfo* rnd;
|
|
if (from_server)
|
|
rnd = &ssl->server_random;
|
|
else
|
|
rnd = &ssl->client_random;
|
|
|
|
/* get provided random for keyring generation*/
|
|
tvb_memcpy(tvb, rnd->data, offset, 32);
|
|
rnd->data_len = 32;
|
|
if (from_server)
|
|
ssl->state |= SSL_SERVER_RANDOM;
|
|
else
|
|
ssl->state |= SSL_CLIENT_RANDOM;
|
|
ssl_debug_printf("dissect_dtls_hnd_hello_common found random state %X\n",
|
|
ssl->state);
|
|
|
|
session_id_length = tvb_get_guint8(tvb, offset + 32);
|
|
/* check stored session id info */
|
|
if (from_server && (session_id_length == ssl->session_id.data_len) &&
|
|
(tvb_memeql(tvb, offset+33, ssl->session_id.data, session_id_length) == 0))
|
|
{
|
|
/* clinet/server id match: try to restore a previous cached session*/
|
|
ssl_restore_session(ssl, dtls_session_hash);
|
|
}
|
|
else {
|
|
tvb_memcpy(tvb,ssl->session_id.data, offset+33, session_id_length);
|
|
ssl->session_id.data_len = session_id_length;
|
|
}
|
|
}
|
|
|
|
if (tree)
|
|
{
|
|
/* show the time */
|
|
gmt_unix_time.secs = tvb_get_ntohl(tvb, offset);
|
|
gmt_unix_time.nsecs = 0;
|
|
proto_tree_add_time(tree, hf_dtls_handshake_random_time,
|
|
tvb, offset, 4, &gmt_unix_time);
|
|
offset += 4;
|
|
|
|
/* show the random bytes */
|
|
proto_tree_add_item(tree, hf_dtls_handshake_random_bytes,
|
|
tvb, offset, 28, 0);
|
|
offset += 28;
|
|
|
|
/* show the session id */
|
|
session_id_length = tvb_get_guint8(tvb, offset);
|
|
proto_tree_add_item(tree, hf_dtls_handshake_session_id_len,
|
|
tvb, offset++, 1, 0);
|
|
if (session_id_length > 0)
|
|
{
|
|
proto_tree_add_bytes_format(tree, hf_dtls_handshake_session_id,
|
|
tvb, offset, session_id_length,
|
|
NULL, "Session ID (%u byte%s)",
|
|
session_id_length,
|
|
plurality(session_id_length, "", "s"));
|
|
offset += session_id_length;
|
|
}
|
|
|
|
}
|
|
|
|
/* XXXX */
|
|
return session_id_length+33;
|
|
}
|
|
|
|
static gint
|
|
dissect_dtls_hnd_hello_ext(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset, guint32 left)
|
|
{
|
|
guint16 extension_length;
|
|
guint16 ext_type;
|
|
guint16 ext_len;
|
|
proto_item *pi;
|
|
proto_tree *ext_tree;
|
|
|
|
if (left < 2)
|
|
return offset;
|
|
|
|
extension_length = tvb_get_ntohs(tvb, offset);
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_extensions_len,
|
|
tvb, offset, 2, extension_length);
|
|
offset += 2;
|
|
left -= 2;
|
|
|
|
while (left >= 4)
|
|
{
|
|
ext_type = tvb_get_ntohs(tvb, offset);
|
|
ext_len = tvb_get_ntohs(tvb, offset + 2);
|
|
|
|
pi = proto_tree_add_text(tree, tvb, offset, 4 + ext_len,
|
|
"Extension: %s",
|
|
val_to_str(ext_type,
|
|
tls_hello_extension_types,
|
|
"Unknown %u"));
|
|
ext_tree = proto_item_add_subtree(pi, ett_dtls_extension);
|
|
if (!ext_tree)
|
|
ext_tree = tree;
|
|
|
|
proto_tree_add_uint(ext_tree, hf_dtls_handshake_extension_type,
|
|
tvb, offset, 2, ext_type);
|
|
offset += 2;
|
|
|
|
proto_tree_add_uint(ext_tree, hf_dtls_handshake_extension_len,
|
|
tvb, offset, 2, ext_len);
|
|
offset += 2;
|
|
|
|
proto_tree_add_bytes_format(ext_tree, hf_dtls_handshake_extension_data,
|
|
tvb, offset, ext_len, NULL,
|
|
"Data (%u byte%s)", ext_len,
|
|
plurality(ext_len, "", "s"));
|
|
offset += ext_len;
|
|
left -= 2 + 2 + ext_len;
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
|
|
static void
|
|
dissect_dtls_hnd_cli_hello(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset, guint32 length,
|
|
SslDecryptSession*ssl)
|
|
{
|
|
/* struct {
|
|
* ProtocolVersion client_version;
|
|
* Random random;
|
|
* SessionID session_id;
|
|
* opaque cookie<0..32>; //new field
|
|
* CipherSuite cipher_suites<2..2^16-1>;
|
|
* CompressionMethod compression_methods<1..2^8-1>;
|
|
* Extension client_hello_extension_list<0..2^16-1>;
|
|
* } ClientHello;
|
|
*
|
|
*/
|
|
proto_tree *ti;
|
|
proto_tree *cs_tree;
|
|
guint16 cipher_suite_length;
|
|
guint8 compression_methods_length;
|
|
guint8 compression_method;
|
|
guint16 start_offset = offset;
|
|
guint8 cookie_length;
|
|
cipher_suite_length = 0;
|
|
compression_methods_length = 0;
|
|
cookie_length = 0;
|
|
|
|
if (tree || ssl)
|
|
{
|
|
/* show the client version */
|
|
if (tree)
|
|
proto_tree_add_item(tree, hf_dtls_handshake_client_version, tvb,
|
|
offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
/* show the fields in common with server hello */
|
|
offset += dissect_dtls_hnd_hello_common(tvb, tree, offset, ssl, 0);
|
|
|
|
/* look for a cookie */
|
|
cookie_length = tvb_get_guint8(tvb, offset);
|
|
if (!tree)
|
|
return;
|
|
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_cookie_len,
|
|
tvb, offset, 1, cookie_length);
|
|
offset ++; /* skip opaque length */
|
|
|
|
if (cookie_length > 0)
|
|
{
|
|
proto_tree_add_bytes_format(tree, hf_dtls_handshake_cookie,
|
|
tvb, offset, cookie_length,
|
|
NULL, "Cookie (%u byte%s)",
|
|
cookie_length,
|
|
plurality(cookie_length, "", "s"));
|
|
offset += cookie_length;
|
|
}
|
|
|
|
/* tell the user how many cipher suites there are */
|
|
cipher_suite_length = tvb_get_ntohs(tvb, offset);
|
|
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_cipher_suites_len,
|
|
tvb, offset, 2, cipher_suite_length);
|
|
offset += 2; /* skip opaque length */
|
|
|
|
if (cipher_suite_length > 0)
|
|
{
|
|
tvb_ensure_bytes_exist(tvb, offset, cipher_suite_length);
|
|
ti = proto_tree_add_none_format(tree,
|
|
hf_dtls_handshake_cipher_suites,
|
|
tvb, offset, cipher_suite_length,
|
|
"Cipher Suites (%u suite%s)",
|
|
cipher_suite_length / 2,
|
|
plurality(cipher_suite_length/2, "", "s"));
|
|
|
|
/* make this a subtree */
|
|
cs_tree = proto_item_add_subtree(ti, ett_dtls_cipher_suites);
|
|
if (!cs_tree)
|
|
{
|
|
cs_tree = tree; /* failsafe */
|
|
}
|
|
|
|
while (cipher_suite_length > 0)
|
|
{
|
|
proto_tree_add_item(cs_tree, hf_dtls_handshake_cipher_suite,
|
|
tvb, offset, 2, FALSE);
|
|
offset += 2;
|
|
cipher_suite_length -= 2;
|
|
}
|
|
}
|
|
|
|
/* tell the user how man compression methods there are */
|
|
compression_methods_length = tvb_get_guint8(tvb, offset);
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_comp_methods_len,
|
|
tvb, offset, 1, compression_methods_length);
|
|
offset++;
|
|
|
|
if (compression_methods_length > 0)
|
|
{
|
|
tvb_ensure_bytes_exist(tvb, offset, compression_methods_length);
|
|
ti = proto_tree_add_none_format(tree,
|
|
hf_dtls_handshake_comp_methods,
|
|
tvb, offset, compression_methods_length,
|
|
"Compression Methods (%u method%s)",
|
|
compression_methods_length,
|
|
plurality(compression_methods_length,
|
|
"", "s"));
|
|
|
|
/* make this a subtree */
|
|
cs_tree = proto_item_add_subtree(ti, ett_dtls_comp_methods);
|
|
if (!cs_tree)
|
|
{
|
|
cs_tree = tree; /* failsafe */
|
|
}
|
|
|
|
while (compression_methods_length > 0)
|
|
{
|
|
compression_method = tvb_get_guint8(tvb, offset);
|
|
if (compression_method < 64)
|
|
proto_tree_add_uint(cs_tree, hf_dtls_handshake_comp_method,
|
|
tvb, offset, 1, compression_method);
|
|
else if (compression_method > 63 && compression_method < 193)
|
|
proto_tree_add_text(cs_tree, tvb, offset, 1,
|
|
"Compression Method: Reserved - to be assigned by IANA (%u)",
|
|
compression_method);
|
|
else
|
|
proto_tree_add_text(cs_tree, tvb, offset, 1,
|
|
"Compression Method: Private use range (%u)",
|
|
compression_method);
|
|
offset++;
|
|
compression_methods_length--;
|
|
}
|
|
}
|
|
|
|
if (length > offset - start_offset)
|
|
{
|
|
offset = dissect_dtls_hnd_hello_ext(tvb, tree, offset,
|
|
length -
|
|
(offset - start_offset));
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static void
|
|
dissect_dtls_hnd_hello_verify_request(tvbuff_t *tvb, proto_tree *tree,
|
|
guint32 offset, SslDecryptSession* ssl)
|
|
{
|
|
/*
|
|
* struct {
|
|
* ProtocolVersion server_version;
|
|
* opaque cookie<0..32>;
|
|
* } HelloVerifyRequest;
|
|
*/
|
|
|
|
guint8 cookie_length;
|
|
cookie_length = 0;
|
|
|
|
if (tree || ssl)
|
|
{
|
|
/* show the client version */
|
|
if (tree)
|
|
proto_tree_add_item(tree, hf_dtls_handshake_server_version, tvb,
|
|
offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
|
|
/* look for a cookie */
|
|
cookie_length = tvb_get_guint8(tvb, offset);
|
|
if (!tree)
|
|
return;
|
|
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_cookie_len,
|
|
tvb, offset, 1, cookie_length);
|
|
offset ++; /* skip opaque length */
|
|
|
|
if (cookie_length > 0)
|
|
{
|
|
proto_tree_add_bytes_format(tree, hf_dtls_handshake_cookie,
|
|
tvb, offset, cookie_length,
|
|
NULL, "Cookie (%u byte%s)",
|
|
cookie_length,
|
|
plurality(cookie_length, "", "s"));
|
|
offset += cookie_length;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
static void
|
|
dissect_dtls_hnd_srv_hello(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset, guint32 length, SslDecryptSession* ssl)
|
|
{
|
|
/* struct {
|
|
* ProtocolVersion server_version;
|
|
* Random random;
|
|
* SessionID session_id;
|
|
* CipherSuite cipher_suite;
|
|
* CompressionMethod compression_method;
|
|
* Extension server_hello_extension_list<0..2^16-1>;
|
|
* } ServerHello;
|
|
*/
|
|
guint16 start_offset;
|
|
start_offset = offset;
|
|
|
|
if (tree || ssl)
|
|
{
|
|
/* show the server version */
|
|
if (tree)
|
|
proto_tree_add_item(tree, hf_dtls_handshake_server_version, tvb,
|
|
offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
/* first display the elements conveniently in
|
|
* common with client hello
|
|
*/
|
|
offset += dissect_dtls_hnd_hello_common(tvb, tree, offset, ssl, 1);
|
|
|
|
/* PAOLO: handle session cipher suite */
|
|
if (ssl) {
|
|
/* store selected cipher suite for decryption */
|
|
ssl->cipher = tvb_get_ntohs(tvb, offset);
|
|
if (ssl_find_cipher(ssl->cipher,&ssl->cipher_suite) < 0) {
|
|
ssl_debug_printf("dissect_dtls_hnd_srv_hello can't find cipher suite %X\n", ssl->cipher);
|
|
goto no_cipher;
|
|
}
|
|
|
|
ssl->state |= SSL_CIPHER;
|
|
ssl_debug_printf("dissect_dtls_hnd_srv_hello found cipher %X, state %X\n",
|
|
ssl->cipher, ssl->state);
|
|
|
|
/* if we have restored a session now we can have enought material
|
|
* to build session key, check it out*/
|
|
if ((ssl->state &
|
|
(SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION|SSL_MASTER_SECRET)) !=
|
|
(SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION|SSL_MASTER_SECRET)) {
|
|
ssl_debug_printf("dissect_dtls_hnd_srv_hello not enough data to generate key (required state %X)\n",
|
|
(SSL_CIPHER|SSL_CLIENT_RANDOM|SSL_SERVER_RANDOM|SSL_VERSION|SSL_MASTER_SECRET));
|
|
goto no_cipher;
|
|
}
|
|
|
|
ssl_debug_printf("dissect_dtls_hnd_srv_hello trying to generate keys\n");
|
|
if (ssl_generate_keyring_material(ssl)<0) {
|
|
ssl_debug_printf("dissect_dtls_hnd_srv_hello can't generate keyring material\n");
|
|
goto no_cipher;
|
|
}
|
|
ssl->state |= SSL_HAVE_SESSION_KEY;
|
|
}
|
|
no_cipher:
|
|
if (!tree)
|
|
return;
|
|
|
|
/* now the server-selected cipher suite */
|
|
proto_tree_add_item(tree, hf_dtls_handshake_cipher_suite,
|
|
tvb, offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
/* and the server-selected compression method */
|
|
proto_tree_add_item(tree, hf_dtls_handshake_comp_method,
|
|
tvb, offset, 1, FALSE);
|
|
offset++;
|
|
|
|
if (length > offset - start_offset)
|
|
{
|
|
offset = dissect_dtls_hnd_hello_ext(tvb, tree, offset,
|
|
length -
|
|
(offset - start_offset));
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
dissect_dtls_hnd_cert(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset, packet_info *pinfo)
|
|
{
|
|
|
|
/* opaque ASN.1Cert<2^24-1>;
|
|
*
|
|
* struct {
|
|
* ASN.1Cert certificate_list<1..2^24-1>;
|
|
* } Certificate;
|
|
*/
|
|
guint32 certificate_list_length;
|
|
proto_tree *ti;
|
|
proto_tree *subtree;
|
|
asn1_ctx_t asn1_ctx;
|
|
asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
|
|
|
|
if (tree)
|
|
{
|
|
certificate_list_length = tvb_get_ntoh24(tvb, offset);
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_certificates_len,
|
|
tvb, offset, 3, certificate_list_length);
|
|
offset += 3; /* 24-bit length value */
|
|
|
|
if (certificate_list_length > 0)
|
|
{
|
|
tvb_ensure_bytes_exist(tvb, offset, certificate_list_length);
|
|
ti = proto_tree_add_none_format(tree,
|
|
hf_dtls_handshake_certificates,
|
|
tvb, offset, certificate_list_length,
|
|
"Certificates (%u byte%s)",
|
|
certificate_list_length,
|
|
plurality(certificate_list_length,
|
|
"", "s"));
|
|
|
|
/* make it a subtree */
|
|
subtree = proto_item_add_subtree(ti, ett_dtls_certs);
|
|
if (!subtree)
|
|
{
|
|
subtree = tree; /* failsafe */
|
|
}
|
|
|
|
/* iterate through each certificate */
|
|
while (certificate_list_length > 0)
|
|
{
|
|
/* get the length of the current certificate */
|
|
guint32 cert_length = tvb_get_ntoh24(tvb, offset);
|
|
certificate_list_length -= 3 + cert_length;
|
|
|
|
proto_tree_add_item(subtree, hf_dtls_handshake_certificate_len,
|
|
tvb, offset, 3, FALSE);
|
|
offset += 3;
|
|
|
|
dissect_x509af_Certificate(FALSE, tvb, offset, &asn1_ctx, subtree, hf_dtls_handshake_certificate);
|
|
offset += cert_length;
|
|
}
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
static void
|
|
dissect_dtls_hnd_cert_req(tvbuff_t *tvb,
|
|
proto_tree *tree, guint32 offset)
|
|
{
|
|
/*
|
|
* enum {
|
|
* rsa_sign(1), dss_sign(2), rsa_fixed_dh(3), dss_fixed_dh(4),
|
|
* (255)
|
|
* } ClientCertificateType;
|
|
*
|
|
* opaque DistinguishedName<1..2^16-1>;
|
|
*
|
|
* struct {
|
|
* ClientCertificateType certificate_types<1..2^8-1>;
|
|
* DistinguishedName certificate_authorities<3..2^16-1>;
|
|
* } CertificateRequest;
|
|
*
|
|
*/
|
|
proto_tree *ti;
|
|
proto_tree *subtree;
|
|
guint8 cert_types_count;
|
|
gint dnames_length;
|
|
cert_types_count = 0;
|
|
dnames_length = 0;
|
|
|
|
if (tree)
|
|
{
|
|
cert_types_count = tvb_get_guint8(tvb, offset);
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_cert_types_count,
|
|
tvb, offset, 1, cert_types_count);
|
|
offset++;
|
|
|
|
if (cert_types_count > 0)
|
|
{
|
|
ti = proto_tree_add_none_format(tree,
|
|
hf_dtls_handshake_cert_types,
|
|
tvb, offset, cert_types_count,
|
|
"Certificate types (%u type%s)",
|
|
cert_types_count,
|
|
plurality(cert_types_count, "", "s"));
|
|
subtree = proto_item_add_subtree(ti, ett_dtls_cert_types);
|
|
if (!subtree)
|
|
{
|
|
subtree = tree;
|
|
}
|
|
|
|
while (cert_types_count > 0)
|
|
{
|
|
proto_tree_add_item(subtree, hf_dtls_handshake_cert_type,
|
|
tvb, offset, 1, FALSE);
|
|
offset++;
|
|
cert_types_count--;
|
|
}
|
|
}
|
|
|
|
dnames_length = tvb_get_ntohs(tvb, offset);
|
|
proto_tree_add_uint(tree, hf_dtls_handshake_dnames_len,
|
|
tvb, offset, 2, dnames_length);
|
|
offset += 2;
|
|
|
|
if (dnames_length > 0)
|
|
{
|
|
tvb_ensure_bytes_exist(tvb, offset, dnames_length);
|
|
ti = proto_tree_add_none_format(tree,
|
|
hf_dtls_handshake_dnames,
|
|
tvb, offset, dnames_length,
|
|
"Distinguished Names (%d byte%s)",
|
|
dnames_length,
|
|
plurality(dnames_length, "", "s"));
|
|
subtree = proto_item_add_subtree(ti, ett_dtls_dnames);
|
|
if (!subtree)
|
|
{
|
|
subtree = tree;
|
|
}
|
|
|
|
while (dnames_length > 0)
|
|
{
|
|
/* get the length of the current certificate */
|
|
guint16 name_length = tvb_get_ntohs(tvb, offset);
|
|
dnames_length -= 2 + name_length;
|
|
|
|
proto_tree_add_item(subtree, hf_dtls_handshake_dname_len,
|
|
tvb, offset, 2, FALSE);
|
|
offset += 2;
|
|
|
|
proto_tree_add_bytes_format(subtree,
|
|
hf_dtls_handshake_dname,
|
|
tvb, offset, name_length, NULL,
|
|
"Distinguished Name (%u byte%s)",
|
|
name_length,
|
|
plurality(name_length, "", "s"));
|
|
offset += name_length;
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
static void
|
|
dissect_dtls_hnd_finished(tvbuff_t *tvb, proto_tree *tree, guint32 offset,
|
|
guint* conv_version)
|
|
{
|
|
/*
|
|
* struct {
|
|
* opaque verify_data[12];
|
|
* } Finished;
|
|
*/
|
|
|
|
/* this all needs a tree, so bail if we don't have one */
|
|
if (!tree)
|
|
{
|
|
return;
|
|
}
|
|
|
|
switch(*conv_version) {
|
|
case SSL_VER_DTLS:
|
|
proto_tree_add_item(tree, hf_dtls_handshake_finished,
|
|
tvb, offset, 12, FALSE);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*********************************************************************
|
|
*
|
|
* Support Functions
|
|
*
|
|
*********************************************************************/
|
|
#if 0
|
|
static void
|
|
ssl_set_conv_version(packet_info *pinfo, guint version)
|
|
{
|
|
conversation_t *conversation;
|
|
|
|
if (pinfo->fd->flags.visited)
|
|
{
|
|
/* We've already processed this frame; no need to do any more
|
|
* work on it.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
conversation = find_or_create_conversation(pinfo);
|
|
|
|
if (conversation_get_proto_data(conversation, proto_dtls) != NULL)
|
|
{
|
|
/* get rid of the current data */
|
|
conversation_delete_proto_data(conversation, proto_dtls);
|
|
}
|
|
conversation_add_proto_data(conversation, proto_dtls, GINT_TO_POINTER(version));
|
|
}
|
|
#endif
|
|
|
|
static gint
|
|
dtls_is_valid_handshake_type(guint8 type)
|
|
{
|
|
|
|
switch (type) {
|
|
case SSL_HND_HELLO_REQUEST:
|
|
case SSL_HND_CLIENT_HELLO:
|
|
case SSL_HND_SERVER_HELLO:
|
|
case SSL_HND_HELLO_VERIFY_REQUEST:
|
|
case SSL_HND_CERTIFICATE:
|
|
case SSL_HND_SERVER_KEY_EXCHG:
|
|
case SSL_HND_CERT_REQUEST:
|
|
case SSL_HND_SVR_HELLO_DONE:
|
|
case SSL_HND_CERT_VERIFY:
|
|
case SSL_HND_CLIENT_KEY_EXCHG:
|
|
case SSL_HND_FINISHED:
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static gint
|
|
dtls_is_authoritative_version_message(guint8 content_type, guint8 next_byte)
|
|
{
|
|
if (content_type == SSL_ID_HANDSHAKE
|
|
&& dtls_is_valid_handshake_type(next_byte))
|
|
{
|
|
return (next_byte != SSL_HND_CLIENT_HELLO);
|
|
}
|
|
else if (ssl_is_valid_content_type(content_type)
|
|
&& content_type != SSL_ID_HANDSHAKE)
|
|
{
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* 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 != DTLSV1DOT0_VERSION_NOT)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*********************************************************************
|
|
*
|
|
* 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_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_DOUBLE, 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_change_cipher_spec,
|
|
{ "Change Cipher Spec Message", "dtls.change_cipher_spec",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"Signals a change in cipher specifications", 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 }
|
|
},
|
|
{ &hf_dtls_handshake_client_version,
|
|
{ "Version", "dtls.handshake.version",
|
|
FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0,
|
|
"Maximum version supported by client", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_server_version,
|
|
{ "Version", "dtls.handshake.version",
|
|
FT_UINT16, BASE_HEX, VALS(ssl_versions), 0x0,
|
|
"Version selected by server", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_random_time,
|
|
{ "Random.gmt_unix_time", "dtls.handshake.random_time",
|
|
FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
|
|
"Unix time field of random structure", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_random_bytes,
|
|
{ "Random.bytes", "dtls.handshake.random",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"Random challenge used to authenticate server", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cipher_suites_len,
|
|
{ "Cipher Suites Length", "dtls.handshake.cipher_suites_length",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Length of cipher suites field", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cipher_suites,
|
|
{ "Cipher Suites", "dtls.handshake.ciphersuites",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"List of cipher suites supported by client", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cipher_suite,
|
|
{ "Cipher Suite", "dtls.handshake.ciphersuite",
|
|
FT_UINT16, BASE_HEX|BASE_EXT_STRING, &ssl_31_ciphersuite_ext, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cookie_len,
|
|
{ "Cookie Length", "dtls.handshake.cookie_length",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"Length of the cookie field", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cookie,
|
|
{ "Cookie", "dtls.handshake.cookie",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_session_id,
|
|
{ "Session ID", "dtls.handshake.session_id",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
"Identifies the DTLS session, allowing later resumption", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_comp_methods_len,
|
|
{ "Compression Methods Length", "dtls.handshake.comp_methods_length",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"Length of compression methods field", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_comp_methods,
|
|
{ "Compression Methods", "dtls.handshake.comp_methods",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"List of compression methods supported by client", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_comp_method,
|
|
{ "Compression Method", "dtls.handshake.comp_method",
|
|
FT_UINT8, BASE_DEC, VALS(ssl_31_compression_method), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_extensions_len,
|
|
{ "Extensions Length", "dtls.handshake.extensions_length",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Length of hello extensions", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_extension_type,
|
|
{ "Type", "dtls.handshake.extension.type",
|
|
FT_UINT16, BASE_HEX, VALS(tls_hello_extension_types), 0x0,
|
|
"Hello extension type", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_extension_len,
|
|
{ "Length", "dtls.handshake.extension.len",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Length of a hello extension", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_extension_data,
|
|
{ "Data", "dtls.handshake.extension.data",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
"Hello Extension data", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_certificates_len,
|
|
{ "Certificates Length", "dtls.handshake.certificates_length",
|
|
FT_UINT24, BASE_DEC, NULL, 0x0,
|
|
"Length of certificates field", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_certificates,
|
|
{ "Certificates", "dtls.handshake.certificates",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"List of certificates", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_certificate,
|
|
{ "Certificate", "dtls.handshake.certificate",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_certificate_len,
|
|
{ "Certificate Length", "dtls.handshake.certificate_length",
|
|
FT_UINT24, BASE_DEC, NULL, 0x0,
|
|
"Length of certificate", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cert_types_count,
|
|
{ "Certificate types count", "dtls.handshake.cert_types_count",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"Count of certificate types", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cert_types,
|
|
{ "Certificate types", "dtls.handshake.cert_types",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"List of certificate types", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_cert_type,
|
|
{ "Certificate type", "dtls.handshake.cert_type",
|
|
FT_UINT8, BASE_DEC, VALS(ssl_31_client_certificate_type), 0x0,
|
|
NULL, HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_finished,
|
|
{ "Verify Data", "dtls.handshake.verify_data",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"Opaque verification data", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_md5_hash,
|
|
{ "MD5 Hash", "dtls.handshake.md5_hash",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"Hash of messages, master_secret, etc.", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_sha_hash,
|
|
{ "SHA-1 Hash", "dtls.handshake.sha_hash",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"Hash of messages, master_secret, etc.", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_session_id_len,
|
|
{ "Session ID Length", "dtls.handshake.session_id_length",
|
|
FT_UINT8, BASE_DEC, NULL, 0x0,
|
|
"Length of session ID field", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_dnames_len,
|
|
{ "Distinguished Names Length", "dtls.handshake.dnames_len",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Length of list of CAs that server trusts", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_dnames,
|
|
{ "Distinguished Names", "dtls.handshake.dnames",
|
|
FT_NONE, BASE_NONE, NULL, 0x0,
|
|
"List of CAs that server trusts", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_dname_len,
|
|
{ "Distinguished Name Length", "dtls.handshake.dname_len",
|
|
FT_UINT16, BASE_DEC, NULL, 0x0,
|
|
"Length of distinguished name", HFILL }
|
|
},
|
|
{ &hf_dtls_handshake_dname,
|
|
{ "Distinguished Name", "dtls.handshake.dname",
|
|
FT_BYTES, BASE_NONE, NULL, 0x0,
|
|
"Distinguished name of a CA that server trusts", 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.error",
|
|
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 }
|
|
},
|
|
};
|
|
|
|
/* Setup protocol subtree array */
|
|
static gint *ett[] = {
|
|
&ett_dtls,
|
|
&ett_dtls_record,
|
|
&ett_dtls_alert,
|
|
&ett_dtls_handshake,
|
|
&ett_dtls_cipher_suites,
|
|
&ett_dtls_comp_methods,
|
|
&ett_dtls_extension,
|
|
&ett_dtls_certs,
|
|
&ett_dtls_cert_types,
|
|
&ett_dtls_dnames,
|
|
&ett_dtls_fragment,
|
|
&ett_dtls_fragments,
|
|
};
|
|
|
|
/* Register the protocol name and description */
|
|
proto_dtls = proto_register_protocol("Datagram Transport Layer Security",
|
|
"DTLS", "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));
|
|
|
|
#ifdef HAVE_LIBGNUTLS
|
|
{
|
|
module_t *dtls_module = prefs_register_protocol(proto_dtls, dtls_parse);
|
|
prefs_register_string_preference(dtls_module, "keys_list", "RSA keys list",
|
|
"semicolon separated list of private RSA keys used for DTLS decryption; "
|
|
"each list entry must be in the form of <ip>,<port>,<protocol>,<key_file_name>"
|
|
"<key_file_name> is the local file name of the RSA private key used by the specified server\n",
|
|
(const gchar **)&dtls_keys_list);
|
|
prefs_register_string_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",
|
|
(const gchar **)&dtls_debug_file_name);
|
|
}
|
|
#endif
|
|
|
|
register_dissector("dtls", dissect_dtls, proto_dtls);
|
|
dtls_handle = find_dissector("dtls");
|
|
|
|
dtls_associations = g_tree_new(ssl_association_cmp);
|
|
|
|
register_init_routine(dtls_init);
|
|
ssl_lib_init();
|
|
dtls_tap = register_tap("dtls");
|
|
ssl_debug_printf("proto_register_dtls: registered tap %s:%d\n",
|
|
"dtls", dtls_tap);
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
|
|
/* add now dissector to default ports.*/
|
|
dtls_parse();
|
|
}
|