From 52a667143929ace46929bfb6ad15b6a856cdbe77 Mon Sep 17 00:00:00 2001 From: Peter Wu Date: Sat, 17 Nov 2018 13:56:12 +0100 Subject: wiretap: add read/write support for Decryption Secrets Block (DSB) Support reading and writing pcapng files with DSBs. A DSB may occur multiple times but should appear before packets that need those decryption secrets (so it cannot be moved to the end like NRB). The TLS dissector will be updated in the future to make use of these secrets. pcapng spec update: https://github.com/pcapng/pcapng/pull/54 As DSBs may be interleaved with packets, do not even try to read it in pcapng_open (as is done for IDBs). Instead process them during the sequential read, appending them to the 'wtap::dsbs' array. Writing is more complicated, secrets may initially not be available when 'wtap_dumper' is created. As they may become available in 'wtap::dsbs' as more packets are read, allow 'wtap_dumper::dsbs_growing' to reference this array. This saves every user from checking/dumping DSBs. If the wtap user needs to insert extra DSBs (while preserving existing DSBs), they can set the 'wtap_dumper::dsbs_initial' field. The test file was creating using a patched editcap (future patch) and combined using mergecap (which required a change to preserve the DSBs). Change-Id: I74e4ee3171bd852a89ea0f6fbae9e0f65ed6eda9 Ping-Bug: 15252 Reviewed-on: https://code.wireshark.org/review/30692 Reviewed-by: Peter Wu Petri-Dish: Peter Wu Tested-by: Petri Dish Buildbot Reviewed-by: Anders Broman --- wiretap/wtap_opttypes.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'wiretap/wtap_opttypes.c') diff --git a/wiretap/wtap_opttypes.c b/wiretap/wtap_opttypes.c index 91690d0e69..c50879e6a6 100644 --- a/wiretap/wtap_opttypes.c +++ b/wiretap/wtap_opttypes.c @@ -972,6 +972,27 @@ static void idb_copy_mand(wtap_block_t dest_block, wtap_block_t src_block) } } +static void dsb_create(wtap_block_t block) +{ + block->mandatory_data = g_new0(wtapng_dsb_mandatory_t, 1); +} + +static void dsb_free_mand(wtap_block_t block) +{ + wtapng_dsb_mandatory_t *mand = (wtapng_dsb_mandatory_t *)block->mandatory_data; + g_free(mand->secrets_data); +} + +static void dsb_copy_mand(wtap_block_t dest_block, wtap_block_t src_block) +{ + wtapng_dsb_mandatory_t *src = (wtapng_dsb_mandatory_t *)src_block->mandatory_data; + wtapng_dsb_mandatory_t *dst = (wtapng_dsb_mandatory_t *)dest_block->mandatory_data; + dst->secrets_type = src->secrets_type; + dst->secrets_len = src->secrets_len; + g_free(dst->secrets_data); + dst->secrets_data = (guint8 *)g_memdup(src->secrets_data, src->secrets_len); +} + void wtap_opttypes_initialize(void) { static wtap_blocktype_t shb_block = { @@ -1082,6 +1103,16 @@ void wtap_opttypes_initialize(void) NULL }; + static wtap_blocktype_t dsb_block = { + WTAP_BLOCK_DSB, + "DSB", + "Decryption Secrets Block", + dsb_create, + dsb_free_mand, + dsb_copy_mand, + NULL + }; + static wtap_blocktype_t nrb_block = { WTAP_BLOCK_NG_NRB, /* block_type */ "NRB", /* name */ @@ -1227,6 +1258,11 @@ void wtap_opttypes_initialize(void) wtap_opttype_option_register(&isb_block, OPT_ISB_FILTERACCEPT, &isb_filteraccept); wtap_opttype_option_register(&isb_block, OPT_ISB_OSDROP, &isb_osdrop); wtap_opttype_option_register(&isb_block, OPT_ISB_USRDELIV, &isb_usrdeliv); + + /* + * Register the DSB, currently no options are defined. + */ + wtap_opttype_block_register(WTAP_BLOCK_DSB, &dsb_block); } void wtap_opttypes_cleanup(void) -- cgit v1.2.3