5 * TrIPE protocol dissector for Wireshark
7 * (c) 2003 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
37 #include <netinet/in.h>
41 #include <wireshark/config.h>
42 #include <wireshark/epan/packet.h>
43 #include <wireshark/epan/prefs.h>
47 /*----- Static variables --------------------------------------------------*/
49 static int proto_tripe = -1;
51 static guint hashsz = 20, tagsz = 10, ivsz = 8;
54 int hf, hf_len, hf_val, tt;
57 int hf, hf_len, hf_val, hfx_len, hfx_val, hfy_len, hfy_val, tt;
60 static int hf_tripe_cat = -1;
61 static int hf_tripe_packet_type = -1;
62 static int hf_tripe_ct = -1;
63 static int hf_tripe_ct_seq = -1;
64 static int hf_tripe_ct_iv = -1;
65 static int hf_tripe_ct_ct = -1;
66 static int hf_tripe_ct_tag = -1;
67 static int hf_tripe_misc_type = -1;
68 static int hf_tripe_misc_payload = -1;
69 static int hf_tripe_kx_type = -1;
70 static hfge hf_tripe_kx_mychal = { -1, -1, -1, -1, -1, -1, -1, -1 };
71 static int hf_tripe_kx_mycookie = -1;
72 static int hf_tripe_kx_yourcookie = -1;
73 static hfmp hf_tripe_kx_check = { -1, -1, -1, -1 };
74 static int hf_tripe_huh = -1;
76 static int tt_tripe = -1;
77 static int tt_tripe_ct = -1;
79 G_MODULE_EXPORT const gchar version[] = VERSION;
81 /*----- Main code ---------------------------------------------------------*/
83 static void prefcb(void) { }
85 static gint gethash(proto_tree *tt, int hf, tvbuff_t *b, gint off)
87 proto_tree_add_item(tt, hf, b, off, hashsz, FALSE);
88 return (off + hashsz);
91 static gint getmp(proto_tree *tt, const hfmp *hf, tvbuff_t *b, gint off)
93 guint16 len = tvb_get_ntohs(b, off);
94 proto_item *ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
95 tt = proto_item_add_subtree(ti, hf->tt);
96 proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
97 proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
98 return (off + 2 + len);
101 static gint getge(proto_tree *tt, const hfge *hf, tvbuff_t *b, gint off)
103 guint16 len = tvb_get_ntohs(b, off), len2;
106 r = tvb_length_remaining(b, off);
108 (len2 = tvb_get_ntohs(b, off + 2 + len), r < 4 + len + len2)) {
109 ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
110 tt = proto_item_add_subtree(ti, hf->tt);
111 proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
112 proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
115 ti = proto_tree_add_item(tt, hf->hf, b, off, len + len2 + 4, FALSE);
116 tt = proto_item_add_subtree(ti, hf->tt);
117 proto_tree_add_item(tt, hf->hfx_len, b, off, 2, FALSE);
118 proto_tree_add_item(tt, hf->hfx_val, b, off + 2, len, FALSE);
119 proto_tree_add_item(tt, hf->hfy_len, b, off + 2 + len, 2, FALSE);
120 proto_tree_add_item(tt, hf->hfy_val, b, off + 4 + len, len2, FALSE);
121 r = off + len + len2 + 4;
126 static void dissect_tripe(tvbuff_t *b, packet_info *p, proto_tree *t)
134 /* --- Initialize the summary cells --- */
136 if (check_col(p->cinfo, COL_PROTOCOL))
137 col_set_str(p->cinfo, COL_PROTOCOL, "TrIPE");
138 if (check_col(p->cinfo, COL_INFO))
139 col_clear(p->cinfo, COL_INFO);
140 ty = tvb_get_guint8(b, 0);
141 if (check_col(p->cinfo, COL_INFO)) {
142 col_clear(p->cinfo, COL_INFO);
143 switch (ty & MSG_CATMASK) {
145 switch (ty & MSG_TYPEMASK) {
147 col_set_str(p->cinfo, COL_INFO, "Packet data");
150 col_add_fstr(p->cinfo, COL_INFO,
151 "Packet data, unknown type code %u",
157 switch (ty & MSG_TYPEMASK) {
159 col_set_str(p->cinfo, COL_INFO, "Key exchange, prechallenge");
162 col_set_str(p->cinfo, COL_INFO, "Key exchange, challenge");
165 col_set_str(p->cinfo, COL_INFO, "Key exchange, reply");
168 col_set_str(p->cinfo, COL_INFO, "Key exchange, switch request");
171 col_set_str(p->cinfo, COL_INFO, "Key exchange, switch response");
174 col_add_fstr(p->cinfo, COL_INFO,
175 "Key exchange, unknown type code %u",
181 switch (ty & MSG_TYPEMASK) {
183 col_set_str(p->cinfo, COL_INFO, "Miscellaneous, no-operation");
186 col_set_str(p->cinfo, COL_INFO, "Miscellaneous, transport ping");
189 col_set_str(p->cinfo, COL_INFO,
190 "Miscellaneous, transport ping reply");
193 col_set_str(p->cinfo, COL_INFO, "Miscellaneous, encrypted ping");
196 col_set_str(p->cinfo, COL_INFO,
197 "Miscellaneous, encrypted ping reply");
200 col_set_str(p->cinfo, COL_INFO,
201 "Miscellaneous, greeting");
204 col_add_fstr(p->cinfo, COL_INFO,
205 "Miscellaneous, unknown type code %u",
211 col_add_fstr(p->cinfo, COL_INFO,
212 "Unknown category code %u, unknown type code %u",
213 ty & MSG_CATMASK, ty & MSG_TYPEMASK);
218 /* --- Fill in the tree --- */
221 ti = proto_tree_add_item(t, proto_tripe, b, 0, -1, FALSE);
222 tt = proto_item_add_subtree(ti, tt_tripe);
224 proto_tree_add_item(tt, hf_tripe_cat, b, 0, 1, FALSE);
227 switch (ty & MSG_CATMASK) {
229 proto_tree_add_item(tt, hf_tripe_packet_type, b, 0, 1, FALSE);
230 switch (ty & MSG_TYPEMASK) {
238 proto_tree_add_item(tt, hf_tripe_kx_type, b, 0, 1, FALSE);
239 switch (ty & MSG_TYPEMASK) {
241 off = getge(tt, &hf_tripe_kx_mychal, b, off);
244 off = getge(tt, &hf_tripe_kx_mychal, b, off);
245 off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
246 off = getmp(tt, &hf_tripe_kx_check, b, off);
249 off = getge(tt, &hf_tripe_kx_mychal, b, off);
250 off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
251 off = getmp(tt, &hf_tripe_kx_check, b, off);
254 off = gethash(tt, hf_tripe_kx_mycookie, b, off);
255 off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
264 proto_tree_add_item(tt, hf_tripe_misc_type, b, 0, 1, FALSE);
265 switch (ty & MSG_TYPEMASK) {
270 proto_tree_add_item(tt, hf_tripe_misc_payload,
284 if (tvb_offset_exists(b, off))
288 proto_tree_add_item(tt, hf_tripe_huh, b, off, -1, FALSE);
291 ti = proto_tree_add_item(tt, hf_tripe_ct, b, off, -1, FALSE);
292 seq = tvb_get_ntohl(b, off + tagsz);
293 proto_item_set_text(ti, "Encrypted ciphertext (sequence number %lu)",
295 tt = proto_item_add_subtree(ti, tt_tripe_ct);
297 proto_tree_add_item(tt, hf_tripe_ct_tag, b, off, tagsz, FALSE);
300 proto_tree_add_item(tt, hf_tripe_ct_seq, b, off, 4, FALSE);
303 proto_tree_add_item(tt, hf_tripe_ct_iv, b, off, ivsz, FALSE);
306 proto_tree_add_item(ti, hf_tripe_ct_ct, b, off, -1, FALSE);
312 void proto_register_tripe(void)
316 static value_string vs_kxtype[] = {
317 { KX_PRECHAL, "KX_PRECHAL (prechallenge)" },
318 { KX_CHAL, "KX_CHAL (challenge)" },
319 { KX_REPLY, "KX_REPLY (reply)" },
320 { KX_SWITCH, "KX_SWITCH (switch request)" },
321 { KX_SWITCHOK, "KX_SWITCHOK (switch response)" },
325 static hf_register_info hfs[] = {
327 "Message category", "tripe.cat",
328 FT_UINT8, BASE_HEX, 0, MSG_CATMASK
330 { &hf_tripe_packet_type, {
331 "Packet message type", "tripe.packet.type",
332 FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
333 "This is the TrIPE packet type subcode."
336 "Encrypted ciphertext", "tripe.ct",
337 FT_BYTES, BASE_NONE, 0, 0,
338 "This is an encrypted message."
340 { &hf_tripe_ct_seq, {
341 "Ciphertext sequence number", "tripe.ct.seq",
342 FT_UINT32, BASE_DEC, 0, 0,
343 "This is the unique sequence number for the ciphertext."
346 "Ciphertext initialization vector", "tripe.ct.iv",
347 FT_BYTES, BASE_NONE, 0, 0,
348 "This is the initialization vector used for the actual encryption."
351 "Actual encrypted data", "tripe.ct.ct",
352 FT_BYTES, BASE_NONE, 0, 0,
353 "This is the encrypted message. Reading it ought to be hard."
355 { &hf_tripe_ct_tag, {
356 "Message authentication code", "tripe.ct.tag",
357 FT_BYTES, BASE_NONE, 0, 0,
358 "This is the message authentication code tag for the ciphertext."
360 { &hf_tripe_misc_type, {
361 "Miscellaneous message type", "tripe.misc.type",
362 FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
363 "This is the TrIPE miscellaneous message type subcode."
365 { &hf_tripe_misc_payload, {
366 "Miscellaneous message payload", "tripe.misc.payload",
367 FT_BYTES, BASE_NONE, 0, 0,
368 "This is the miscellaneous message payload."
370 { &hf_tripe_kx_type, {
371 "Key-exchange message type", "tripe.kx.type",
372 FT_UINT8, BASE_HEX, vs_kxtype, MSG_TYPEMASK,
373 "This is the TrIPE key-exchange type subcode."
375 { &hf_tripe_kx_mychal.hf, {
376 "Sender's challenge data", "tripe.kx.mychal",
377 FT_BYTES, BASE_NONE, 0, 0,
378 "This is the sender's challenge."
380 { &hf_tripe_kx_mychal.hf_len, {
381 "Challenge length", "tripe.kx.mychal.len",
382 FT_UINT16, BASE_DEC, 0, 0,
383 "This is the length of the sender's challenge."
385 { &hf_tripe_kx_mychal.hf_val, {
386 "Challenge", "tripe.kx.mychal.val",
387 FT_BYTES, BASE_NONE, 0, 0,
388 "This is the value of the sender's challenge."
390 { &hf_tripe_kx_mychal.hfx_len, {
391 "Challenge x length", "tripe.kx.mychal.x.len",
392 FT_UINT16, BASE_DEC, 0, 0,
393 "This is the length of the sender's challenge x-coordinate."
395 { &hf_tripe_kx_mychal.hfx_val, {
396 "Challenge x value", "tripe.kx.mychal.x.val",
397 FT_BYTES, BASE_NONE, 0, 0,
398 "This is the value of the sender's challenge x-coordinate."
400 { &hf_tripe_kx_mychal.hfy_len, {
401 "Challenge y length", "tripe.kx.mychal.y.len",
402 FT_UINT16, BASE_DEC, 0, 0,
403 "This is the length of the sender's challenge x-coordinate."
405 { &hf_tripe_kx_mychal.hfy_val, {
406 "Challenge y value", "tripe.kx.mychal.y.val",
407 FT_BYTES, BASE_NONE, 0, 0,
408 "This is the value of the sender's challenge x-coordinate."
410 { &hf_tripe_kx_mycookie, {
411 "Sender's hashed cookie", "tripe.kx.mycookie",
412 FT_BYTES, BASE_NONE, 0, 0,
413 "This is the hash of the sender's challenge."
415 { &hf_tripe_kx_yourcookie, {
416 "Recipient's hashed cookie", "tripe.kx.yourcookie",
417 FT_BYTES, BASE_NONE, 0, 0,
418 "This is the hash of the recipient's challenge."
420 { &hf_tripe_kx_check.hf, {
421 "Challenge check-value", "tripe.kx.check",
422 FT_BYTES, BASE_NONE, 0, 0,
423 "This is an encrypted check-value which proves that the sender "
424 "knows the answer to the challenge, and that it is therefore honest."
426 { &hf_tripe_kx_check.hf_len, {
427 "Check-value length", "tripe.kx.check.len",
428 FT_UINT16, BASE_DEC, 0, 0,
429 "This is the length of the encrypted check-value."
431 { &hf_tripe_kx_check.hf_val, {
432 "Check-value data", "tripe.kx.check.val",
433 FT_BYTES, BASE_NONE, 0, 0,
434 "This is the actual encrypted check-value."
437 "Unknown data", "tripe.huh",
438 FT_BYTES, BASE_NONE, 0, 0,
439 "I don't know what's meant to appear here."
443 static gint *tts[] = {
446 &hf_tripe_kx_mychal.tt,
447 &hf_tripe_kx_check.tt,
450 proto_tripe = proto_register_protocol("TrIPE", "TrIPE", "tripe");
451 proto_register_field_array(proto_tripe, hfs, array_length(hfs));
452 proto_register_subtree_array(tts, array_length(tts));
454 mod = prefs_register_protocol(proto_tripe, prefcb);
455 prefs_register_uint_preference(mod, "hashsz", "Hash length",
456 "hash function output length (in octets)",
458 prefs_register_uint_preference(mod, "tagsz", "MAC tag length",
459 "MAC tag length (in octets)", 10, &tagsz);
460 prefs_register_uint_preference(mod, "ivsz", "IV length",
461 "block cipher initialization vector length"
466 void proto_reg_handoff_tripe(void)
468 dissector_handle_t dh;
470 dh = create_dissector_handle(dissect_tripe, proto_tripe);
471 dissector_add("udp.port", 22003, dh);
474 G_MODULE_EXPORT void plugin_reg_handoff(void)
476 proto_reg_handoff_tripe();
479 G_MODULE_EXPORT void plugin_register(void)
481 if (proto_tripe == -1)
482 proto_register_tripe();
485 /*----- That's all, folks -------------------------------------------------*/