[tripe] / ethereal / packet-tripe.c

/* -*-c-*-
 *
 * $Id$
 *
 * TrIPE protocol dissector for Ethereal
 *
 * (c) 2003 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Trivial IP Encryption (TrIPE).
 *
 * TrIPE is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * TrIPE is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with TrIPE; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Header files ------------------------------------------------------*/

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <netinet/in.h>

#include <glib.h>
#include <gmodule.h>
#include <ethereal/config.h>
#include <ethereal/epan/packet.h>
#include <ethereal/epan/prefs.h>

#include "tripe-protocol.h"

/*----- Static variables --------------------------------------------------*/

static int proto_tripe = -1;

static guint hashsz = 20, tagsz = 10, ivsz = 8;

typedef struct hfmp {
  int hf, hf_len, hf_val, tt;
} hfmp;
typedef struct hfge {
  int hf, hf_len, hf_val, hfx_len, hfx_val, hfy_len, hfy_val, tt;
} hfge;

static int hf_tripe_cat = -1;
static int hf_tripe_packet_type = -1;
static int hf_tripe_ct = -1;
static int hf_tripe_ct_seq = -1;
static int hf_tripe_ct_iv = -1;
static int hf_tripe_ct_ct = -1;
static int hf_tripe_ct_tag = -1;
static int hf_tripe_kx_type = -1;
static hfge hf_tripe_kx_mychal = { -1, -1, -1, -1, -1, -1, -1, -1 };
static int hf_tripe_kx_mycookie = -1;
static int hf_tripe_kx_yourcookie = -1;
static hfmp hf_tripe_kx_check = { -1, -1, -1, -1 };
static int hf_tripe_huh = -1;

static int tt_tripe = -1;
static int tt_tripe_ct = -1;

G_MODULE_EXPORT const gchar version[] = VERSION;

/*----- Main code ---------------------------------------------------------*/

static void prefcb(void) { }

static gint gethash(proto_tree *tt, int hf, tvbuff_t *b, gint off)
{
  proto_tree_add_item(tt, hf, b, off, hashsz, FALSE);
  return (off + hashsz); 
}

static gint getmp(proto_tree *tt, const hfmp *hf, tvbuff_t *b, gint off)
{
  guint16 len = tvb_get_ntohs(b, off);
  proto_item *ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
  tt = proto_item_add_subtree(ti, hf->tt);
  proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
  proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
  return (off + 2 + len);
}

static gint getge(proto_tree *tt, const hfge *hf, tvbuff_t *b, gint off)
{
  guint16 len = tvb_get_ntohs(b, off), len2;
  guint r;
  proto_item *ti;
  r = tvb_length_remaining(b, off);
  if (r < 4 + len ||
      (len2 = tvb_get_ntohs(b, off + 2 + len), r < 4 + len + len2)) {
    ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
    tt = proto_item_add_subtree(ti, hf->tt);
    proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
    proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
    r = off + len + 2;
  } else {
    ti = proto_tree_add_item(tt, hf->hf, b, off, len + len2 + 4, FALSE);
    tt = proto_item_add_subtree(ti, hf->tt);
    proto_tree_add_item(tt, hf->hfx_len, b, off, 2, FALSE);
    proto_tree_add_item(tt, hf->hfx_val, b, off + 2, len, FALSE);
    proto_tree_add_item(tt, hf->hfy_len, b, off + 2 + len, 2, FALSE);
    proto_tree_add_item(tt, hf->hfy_val, b, off + 4 + len, len2, FALSE);
    r = off + len + len2 + 4;
  }    
  return (r);
}

static void dissect_tripe(tvbuff_t *b, packet_info *p, proto_tree *t)
{
  proto_item *ti;
  proto_tree *tt;
  guint8 ty;
  gint off = 0;
  guint32 seq;

  /* --- Initialize the summary cells --- */

  if (check_col(p->cinfo, COL_PROTOCOL))
    col_set_str(p->cinfo, COL_PROTOCOL, "TrIPE");
  if (check_col(p->cinfo, COL_INFO))
    col_clear(p->cinfo, COL_INFO);
  ty = tvb_get_guint8(b, 0);
  if (check_col(p->cinfo, COL_INFO)) {
    col_clear(p->cinfo, COL_INFO);
    switch (ty & MSG_CATMASK) {
      case MSG_PACKET:
	switch (ty & MSG_TYPEMASK) {
	  case 0:
	    col_set_str(p->cinfo, COL_INFO, "Packet data");
	    break;
	  default:
	    col_add_fstr(p->cinfo, COL_INFO,
			 "Packet data, unknown type code %u",
			 ty & MSG_TYPEMASK);
	    break;
	}
	break;
      case MSG_KEYEXCH:
	switch (ty & MSG_TYPEMASK) {
	  case KX_PRECHAL:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, prechallenge");
	    break;
	  case KX_COOKIE:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, cookie");
	    break;
	  case KX_CHAL:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, challenge");
	    break;
	  case KX_REPLY:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, reply");
	    break;
	  case KX_SWITCH:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, switch request");
	    break;
	  case KX_SWITCHOK:
	    col_set_str(p->cinfo, COL_INFO, "Key exchange, switch response");
	    break;
	  default:
	    col_add_fstr(p->cinfo, COL_INFO,
			 "Key exchange, unknown type code %u",
			 ty & MSG_TYPEMASK);
	    break;
	}
	break;
      default:
	col_add_fstr(p->cinfo, COL_INFO,
		     "Unknown category code %u, unknown type code %u",
		     ty & MSG_CATMASK, ty & MSG_TYPEMASK);
	break;
    }
  }

  /* --- Fill in the tree --- */

  if (t) {
    ti = proto_tree_add_item(t, proto_tripe, b, 0, -1, FALSE);
    tt = proto_item_add_subtree(ti, tt_tripe);

    proto_tree_add_item(tt, hf_tripe_cat, b, 0, 1, FALSE);

    off = 1;
    switch (ty & MSG_CATMASK) {
      case MSG_PACKET:
	proto_tree_add_item(tt, hf_tripe_packet_type, b, 0, 1, FALSE);
	switch (ty & MSG_TYPEMASK) {
	  case 0:
	    goto ct;
	  default:
	    goto huh;
	}
	break;
      case MSG_KEYEXCH:
	proto_tree_add_item(tt, hf_tripe_kx_type, b, 0, 1, FALSE);
	switch (ty & MSG_TYPEMASK) {
	  case KX_PRECHAL:
	    off = getge(tt, &hf_tripe_kx_mychal, b, off);
	    goto tail;
	  case KX_COOKIE:
	    off = getge(tt, &hf_tripe_kx_mychal, b, off);
	    off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	    goto tail;
	  case KX_CHAL:
	    off = getge(tt, &hf_tripe_kx_mychal, b, off);
	    off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	    off = getmp(tt, &hf_tripe_kx_check, b, off);
	    goto tail;
	  case KX_REPLY:
	    off = gethash(tt, hf_tripe_kx_mycookie, b, off);
	    off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	    off = getmp(tt, &hf_tripe_kx_check, b, off);
	    goto ct;
	  case KX_SWITCH:
	    off = gethash(tt, hf_tripe_kx_mycookie, b, off);
	    off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	    goto ct;
	  case KX_SWITCHOK:
	    goto ct;
	  default:
	    goto huh;
	}
	break;
      default:
	goto huh;
    }
  tail:
    if (tvb_offset_exists(b, off))
      goto huh;
    goto done;
  huh:
    proto_tree_add_item(tt, hf_tripe_huh, b, off, -1, FALSE);
    goto done;
  ct:
    ti = proto_tree_add_item(tt, hf_tripe_ct, b, off, -1, FALSE);
    seq = tvb_get_ntohl(b, off + tagsz);
    proto_item_set_text(ti, "Encrypted ciphertext (sequence number %lu)",
			(unsigned long)seq);
    tt = proto_item_add_subtree(ti, tt_tripe_ct);
    if (tagsz) {
      proto_tree_add_item(tt, hf_tripe_ct_tag, b, off, tagsz, FALSE);
      off += tagsz;
    }
    proto_tree_add_item(tt, hf_tripe_ct_seq, b, off, 4, FALSE);
    off += 4;
    if (ivsz) {
      proto_tree_add_item(tt, hf_tripe_ct_iv, b, off, ivsz, FALSE);
      off += ivsz;
    }
    proto_tree_add_item(ti, hf_tripe_ct_ct, b, off, -1, FALSE);
    goto done;
  done:;
  }  
}

void proto_register_tripe(void)
{
  module_t *mod;

  static value_string vs_kxtype[] = {
    { KX_PRECHAL,	"KX_PRECHAL (prechallenge)" },
    { KX_COOKIE,	"KX_COOKIE (cookie)" },
    { KX_CHAL,		"KX_CHAL (challenge)" },
    { KX_REPLY,		"KX_REPLY (reply)" },
    { KX_SWITCH,	"KX_SWITCH (switch request)" },
    { KX_SWITCHOK,	"KX_SWITCHOK (switch response)" },
    { 0,		0 }
  };

  static hf_register_info hfs[] = {
    { &hf_tripe_cat, {
      "Message category", "tripe.cat",
      FT_UINT8, BASE_HEX, 0, MSG_CATMASK
    } },
    { &hf_tripe_packet_type, {
      "Packet message type", "tripe.packet.type",
      FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
      "This is the TrIPE packet type subcode."
    } },
    { &hf_tripe_ct, {
      "Encrypted ciphertext", "tripe.ct",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is an encrypted message."
    } },
    { &hf_tripe_ct_seq, {
      "Ciphertext sequence number", "tripe.ct.seq",
      FT_UINT32, BASE_DEC, 0, 0,
      "This is the unique sequence number for the ciphertext."
    } },
    { &hf_tripe_ct_iv, {
      "Ciphertext initialization vector", "tripe.ct.iv",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the initialization vector used for the actual encryption."
    } },
    { &hf_tripe_ct_ct, {
      "Actual encrypted data", "tripe.ct.ct",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the encrypted message.  Reading it ought to be hard."
    } },
    { &hf_tripe_ct_tag, {
      "Message authentication code", "tripe.ct.tag",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the message authentication code tag for the ciphertext."
    } },
    { &hf_tripe_kx_type, {
      "Key-exchange message type", "tripe.kx.type",
      FT_UINT8, BASE_HEX, vs_kxtype, MSG_TYPEMASK,
      "This is the TrIPE key-exchange type subcode."
    } },
    { &hf_tripe_kx_mychal.hf, {
      "Sender's challenge data", "tripe.kx.mychal",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the sender's challenge."
    } },
    { &hf_tripe_kx_mychal.hf_len, {
      "Challenge length", "tripe.kx.mychal.len",
      FT_UINT16, BASE_DEC, 0, 0,
      "This is the length of the sender's challenge."
    } },
    { &hf_tripe_kx_mychal.hf_val, {
      "Challenge", "tripe.kx.mychal.val",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the value of the sender's challenge."
    } },
    { &hf_tripe_kx_mychal.hfx_len, {
      "Challenge x length", "tripe.kx.mychal.x.len",
      FT_UINT16, BASE_DEC, 0, 0,
      "This is the length of the sender's challenge x-coordinate."
    } },
    { &hf_tripe_kx_mychal.hfy_val, {
      "Challenge x value", "tripe.kx.mychal.x.val",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the value of the sender's challenge x-coordinate."
    } },
    { &hf_tripe_kx_mychal.hfy_len, {
      "Challenge y length", "tripe.kx.mychal.y.len",
      FT_UINT16, BASE_DEC, 0, 0,
      "This is the length of the sender's challenge x-coordinate."
    } },
    { &hf_tripe_kx_mychal.hfx_val, {
      "Challenge y value", "tripe.kx.mychal.y.val",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the value of the sender's challenge x-coordinate."
    } },
    { &hf_tripe_kx_mycookie, {
      "Sender's hashed cookie", "tripe.kx.mycookie",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the hash of the sender's challenge."
    } },
    { &hf_tripe_kx_yourcookie, {
      "Recipient's hashed cookie", "tripe.kx.yourcookie",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the hash of the recipient's challenge."
    } },
    { &hf_tripe_kx_check.hf, {
      "Challenge check-value", "tripe.kx.check",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is an encrypted check-value which proves that the sender "
      "knows the answer to the challenge, and that it is therefore honest."
    } },
    { &hf_tripe_kx_check.hf_len, {
      "Check-value length", "tripe.kx.check.len",
      FT_UINT16, BASE_DEC, 0, 0,
      "This is the length of the encrypted check-value."
    } },
    { &hf_tripe_kx_check.hf_val, {
      "Check-value data", "tripe.kx.check.val",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the actual encrypted check-value."
    } },
    { &hf_tripe_huh, {
      "Unknown data", "tripe.huh",
      FT_BYTES, BASE_NONE, 0, 0,
      "I don't know what's meant to appear here."
    } },
  };

  static gint *tts[] = {
    &tt_tripe,
    &tt_tripe_ct,
    &hf_tripe_kx_mychal.tt,
    &hf_tripe_kx_check.tt,
  };

  proto_tripe = proto_register_protocol("TrIPE", "TrIPE", "tripe");
  proto_register_field_array(proto_tripe, hfs, array_length(hfs));
  proto_register_subtree_array(tts, array_length(tts));

  mod = prefs_register_protocol(proto_tripe, prefcb);
  prefs_register_uint_preference(mod, "hashsz", "Hash length",
				 "hash function output length (in octets)",
				 10, &hashsz);
  prefs_register_uint_preference(mod, "tagsz", "MAC tag length",
				 "MAC tag length (in octets)", 10, &tagsz);
  prefs_register_uint_preference(mod, "ivsz", "IV length",
				 "block cipher initialization vector length"
				 " (in octets)",
				 10, &ivsz);
}

void proto_reg_handoff_tripe(void)
{
  dissector_handle_t dh;

  dh = create_dissector_handle(dissect_tripe, proto_tripe);
  dissector_add("udp.port", 22003, dh);
}

G_MODULE_EXPORT void plugin_reg_handoff(void)
{
  proto_reg_handoff_tripe();
}

G_MODULE_EXPORT void plugin_register(void)
{
  if (proto_tripe == -1)
    proto_register_tripe();
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
165db1a8	1	/* --c--
165db1a8	2	*
3cdc3f3a	3	* $Id$
165db1a8	4	*
	5	* TrIPE protocol dissector for Ethereal
	6	*
	7	* (c) 2003 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of Trivial IP Encryption (TrIPE).
	13	*
	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.
	18	*
	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.
	23	*
	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.
	27	*/
	28
165db1a8	29	/----- Header files ------------------------------------------------------/
	30
	31	#include "config.h"
	32
	33	#include <stdio.h>
	34	#include <stdlib.h>
	35	#include <string.h>
	36
	37	#include <netinet/in.h>
	38
	39	#include <glib.h>
	40	#include <gmodule.h>
3cdc3f3a	41	#include <ethereal/config.h>
	42	#include <ethereal/epan/packet.h>
	43	#include <ethereal/epan/prefs.h>
165db1a8	44
	45	#include "tripe-protocol.h"
	46
	47	/----- Static variables --------------------------------------------------/
	48
	49	static int proto_tripe = -1;
	50
b5c45da1	51	static guint hashsz = 20, tagsz = 10, ivsz = 8;
b5c45da1	52
52c03a2a	53	typedef struct hfmp {
	54	int hf, hf_len, hf_val, tt;
	55	} hfmp;
	56	typedef struct hfge {
	57	int hf, hf_len, hf_val, hfx_len, hfx_val, hfy_len, hfy_val, tt;
	58	} hfge;
165db1a8	59
	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;
b5c45da1	65	static int hf_tripe_ct_ct = -1;
b5c45da1	66	static int hf_tripe_ct_tag = -1;
165db1a8	67	static int hf_tripe_kx_type = -1;
52c03a2a	68	static hfge hf_tripe_kx_mychal = { -1, -1, -1, -1, -1, -1, -1, -1 };
165db1a8	69	static int hf_tripe_kx_mycookie = -1;
	70	static int hf_tripe_kx_yourcookie = -1;
	71	static hfmp hf_tripe_kx_check = { -1, -1, -1, -1 };
	72	static int hf_tripe_huh = -1;
	73
	74	static int tt_tripe = -1;
	75	static int tt_tripe_ct = -1;
	76
	77	G_MODULE_EXPORT const gchar version[] = VERSION;
	78
	79	/----- Main code ---------------------------------------------------------/
	80
b5c45da1	81	static void prefcb(void) { }
b5c45da1	82
165db1a8	83	static gint gethash(proto_tree tt, int hf, tvbuff_t b, gint off)
165db1a8	84	{
b5c45da1	85	proto_tree_add_item(tt, hf, b, off, hashsz, FALSE);
b5c45da1	86	return (off + hashsz);
165db1a8	87	}
	88
	89	static gint getmp(proto_tree tt, const hfmp hf, tvbuff_t *b, gint off)
	90	{
	91	guint16 len = tvb_get_ntohs(b, off);
	92	proto_item *ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
	93	tt = proto_item_add_subtree(ti, hf->tt);
	94	proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
	95	proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
	96	return (off + 2 + len);
	97	}
	98
52c03a2a	99	static gint getge(proto_tree tt, const hfge hf, tvbuff_t *b, gint off)
	100	{
	101	guint16 len = tvb_get_ntohs(b, off), len2;
	102	guint r;
	103	proto_item *ti;
	104	r = tvb_length_remaining(b, off);
	105	if (r < 4 + len \|\|
	106	(len2 = tvb_get_ntohs(b, off + 2 + len), r < 4 + len + len2)) {
	107	ti = proto_tree_add_item(tt, hf->hf, b, off, len + 2, FALSE);
	108	tt = proto_item_add_subtree(ti, hf->tt);
	109	proto_tree_add_item(tt, hf->hf_len, b, off, 2, FALSE);
	110	proto_tree_add_item(tt, hf->hf_val, b, off + 2, len, FALSE);
	111	r = off + len + 2;
	112	} else {
	113	ti = proto_tree_add_item(tt, hf->hf, b, off, len + len2 + 4, FALSE);
	114	tt = proto_item_add_subtree(ti, hf->tt);
	115	proto_tree_add_item(tt, hf->hfx_len, b, off, 2, FALSE);
	116	proto_tree_add_item(tt, hf->hfx_val, b, off + 2, len, FALSE);
	117	proto_tree_add_item(tt, hf->hfy_len, b, off + 2 + len, 2, FALSE);
	118	proto_tree_add_item(tt, hf->hfy_val, b, off + 4 + len, len2, FALSE);
	119	r = off + len + len2 + 4;
	120	}
	121	return (r);
	122	}
	123
165db1a8	124	static void dissect_tripe(tvbuff_t b, packet_info p, proto_tree *t)
	125	{
	126	proto_item *ti;
	127	proto_tree *tt;
	128	guint8 ty;
3cdc3f3a	129	gint off = 0;
165db1a8	130	guint32 seq;
	131
	132	/* --- Initialize the summary cells --- */
	133
	134	if (check_col(p->cinfo, COL_PROTOCOL))
	135	col_set_str(p->cinfo, COL_PROTOCOL, "TrIPE");
3cdc3f3a	136	if (check_col(p->cinfo, COL_INFO))
3cdc3f3a	137	col_clear(p->cinfo, COL_INFO);
165db1a8	138	ty = tvb_get_guint8(b, 0);
	139	if (check_col(p->cinfo, COL_INFO)) {
	140	col_clear(p->cinfo, COL_INFO);
	141	switch (ty & MSG_CATMASK) {
	142	case MSG_PACKET:
	143	switch (ty & MSG_TYPEMASK) {
	144	case 0:
	145	col_set_str(p->cinfo, COL_INFO, "Packet data");
	146	break;
	147	default:
	148	col_add_fstr(p->cinfo, COL_INFO,
	149	"Packet data, unknown type code %u",
	150	ty & MSG_TYPEMASK);
	151	break;
	152	}
	153	break;
	154	case MSG_KEYEXCH:
	155	switch (ty & MSG_TYPEMASK) {
	156	case KX_PRECHAL:
	157	col_set_str(p->cinfo, COL_INFO, "Key exchange, prechallenge");
	158	break;
	159	case KX_COOKIE:
	160	col_set_str(p->cinfo, COL_INFO, "Key exchange, cookie");
	161	break;
	162	case KX_CHAL:
	163	col_set_str(p->cinfo, COL_INFO, "Key exchange, challenge");
	164	break;
	165	case KX_REPLY:
	166	col_set_str(p->cinfo, COL_INFO, "Key exchange, reply");
	167	break;
	168	case KX_SWITCH:
	169	col_set_str(p->cinfo, COL_INFO, "Key exchange, switch request");
	170	break;
	171	case KX_SWITCHOK:
	172	col_set_str(p->cinfo, COL_INFO, "Key exchange, switch response");
	173	break;
	174	default:
	175	col_add_fstr(p->cinfo, COL_INFO,
	176	"Key exchange, unknown type code %u",
	177	ty & MSG_TYPEMASK);
	178	break;
	179	}
	180	break;
	181	default:
	182	col_add_fstr(p->cinfo, COL_INFO,
	183	"Unknown category code %u, unknown type code %u",
	184	ty & MSG_CATMASK, ty & MSG_TYPEMASK);
	185	break;
	186	}
	187	}
	188
	189	/* --- Fill in the tree --- */
	190
	191	if (t) {
	192	ti = proto_tree_add_item(t, proto_tripe, b, 0, -1, FALSE);
	193	tt = proto_item_add_subtree(ti, tt_tripe);
	194
	195	proto_tree_add_item(tt, hf_tripe_cat, b, 0, 1, FALSE);
	196
	197	off = 1;
	198	switch (ty & MSG_CATMASK) {
	199	case MSG_PACKET:
	200	proto_tree_add_item(tt, hf_tripe_packet_type, b, 0, 1, FALSE);
	201	switch (ty & MSG_TYPEMASK) {
202	case 0:
203	goto ct;
204	default:
205	goto huh;
206	}
207	break;
208	case MSG_KEYEXCH:
209	proto_tree_add_item(tt, hf_tripe_kx_type, b, 0, 1, FALSE);
210	switch (ty & MSG_TYPEMASK) {
211	case KX_PRECHAL:
52c03a2a	212	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	213	goto tail;
165db1a8	214	case KX_COOKIE:
52c03a2a	215	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	216	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	217	goto tail;
	218	case KX_CHAL:
52c03a2a	219	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	220	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	221	off = getmp(tt, &hf_tripe_kx_check, b, off);
	222	goto tail;
	223	case KX_REPLY:
	224	off = gethash(tt, hf_tripe_kx_mycookie, b, off);
	225	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	226	off = getmp(tt, &hf_tripe_kx_check, b, off);
	227	goto ct;
	228	case KX_SWITCH:
	229	off = gethash(tt, hf_tripe_kx_mycookie, b, off);
	230	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	231	goto ct;
	232	case KX_SWITCHOK:
	233	goto ct;
	234	default:
	235	goto huh;
	236	}
	237	break;
	238	default:
	239	goto huh;
	240	}
	241	tail:
	242	if (tvb_offset_exists(b, off))
	243	goto huh;
	244	goto done;
	245	huh:
	246	proto_tree_add_item(tt, hf_tripe_huh, b, off, -1, FALSE);
	247	goto done;
	248	ct:
	249	ti = proto_tree_add_item(tt, hf_tripe_ct, b, off, -1, FALSE);
b5c45da1	250	seq = tvb_get_ntohl(b, off + tagsz);
165db1a8	251	proto_item_set_text(ti, "Encrypted ciphertext (sequence number %lu)",
	252	(unsigned long)seq);
	253	tt = proto_item_add_subtree(ti, tt_tripe_ct);
b5c45da1	254	if (tagsz) {
	255	proto_tree_add_item(tt, hf_tripe_ct_tag, b, off, tagsz, FALSE);
	256	off += tagsz;
	257	}
165db1a8	258	proto_tree_add_item(tt, hf_tripe_ct_seq, b, off, 4, FALSE);
165db1a8	259	off += 4;
b5c45da1	260	if (ivsz) {
	261	proto_tree_add_item(tt, hf_tripe_ct_iv, b, off, ivsz, FALSE);
	262	off += ivsz;
	263	}
	264	proto_tree_add_item(ti, hf_tripe_ct_ct, b, off, -1, FALSE);
165db1a8	265	goto done;
	266	done:;
	267	}
	268	}
	269
	270	void proto_register_tripe(void)
	271	{
b5c45da1	272	module_t *mod;
b5c45da1	273
165db1a8	274	static value_string vs_kxtype[] = {
	275	{ KX_PRECHAL, "KX_PRECHAL (prechallenge)" },
	276	{ KX_COOKIE, "KX_COOKIE (cookie)" },
	277	{ KX_CHAL, "KX_CHAL (challenge)" },
	278	{ KX_REPLY, "KX_REPLY (reply)" },
	279	{ KX_SWITCH, "KX_SWITCH (switch request)" },
	280	{ KX_SWITCHOK, "KX_SWITCHOK (switch response)" },
	281	{ 0, 0 }
	282	};
	283
	284	static hf_register_info hfs[] = {
3cdc3f3a	285	{ &hf_tripe_cat, {
165db1a8	286	"Message category", "tripe.cat",
165db1a8	287	FT_UINT8, BASE_HEX, 0, MSG_CATMASK
3cdc3f3a	288	} },
3cdc3f3a	289	{ &hf_tripe_packet_type, {
165db1a8	290	"Packet message type", "tripe.packet.type",
	291	FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
	292	"This is the TrIPE packet type subcode."
3cdc3f3a	293	} },
3cdc3f3a	294	{ &hf_tripe_ct, {
165db1a8	295	"Encrypted ciphertext", "tripe.ct",
	296	FT_BYTES, BASE_NONE, 0, 0,
	297	"This is an encrypted message."
3cdc3f3a	298	} },
3cdc3f3a	299	{ &hf_tripe_ct_seq, {
165db1a8	300	"Ciphertext sequence number", "tripe.ct.seq",
	301	FT_UINT32, BASE_DEC, 0, 0,
	302	"This is the unique sequence number for the ciphertext."
3cdc3f3a	303	} },
3cdc3f3a	304	{ &hf_tripe_ct_iv, {
165db1a8	305	"Ciphertext initialization vector", "tripe.ct.iv",
	306	FT_BYTES, BASE_NONE, 0, 0,
	307	"This is the initialization vector used for the actual encryption."
3cdc3f3a	308	} },
3cdc3f3a	309	{ &hf_tripe_ct_ct, {
b5c45da1	310	"Actual encrypted data", "tripe.ct.ct",
165db1a8	311	FT_BYTES, BASE_NONE, 0, 0,
b5c45da1	312	"This is the encrypted message. Reading it ought to be hard."
3cdc3f3a	313	} },
3cdc3f3a	314	{ &hf_tripe_ct_tag, {
b5c45da1	315	"Message authentication code", "tripe.ct.tag",
165db1a8	316	FT_BYTES, BASE_NONE, 0, 0,
b5c45da1	317	"This is the message authentication code tag for the ciphertext."
3cdc3f3a	318	} },
3cdc3f3a	319	{ &hf_tripe_kx_type, {
165db1a8	320	"Key-exchange message type", "tripe.kx.type",
	321	FT_UINT8, BASE_HEX, vs_kxtype, MSG_TYPEMASK,
	322	"This is the TrIPE key-exchange type subcode."
3cdc3f3a	323	} },
3cdc3f3a	324	{ &hf_tripe_kx_mychal.hf, {
165db1a8	325	"Sender's challenge data", "tripe.kx.mychal",
165db1a8	326	FT_BYTES, BASE_NONE, 0, 0,
52c03a2a	327	"This is the sender's challenge."
3cdc3f3a	328	} },
3cdc3f3a	329	{ &hf_tripe_kx_mychal.hf_len, {
165db1a8	330	"Challenge length", "tripe.kx.mychal.len",
165db1a8	331	FT_UINT16, BASE_DEC, 0, 0,
52c03a2a	332	"This is the length of the sender's challenge."
3cdc3f3a	333	} },
3cdc3f3a	334	{ &hf_tripe_kx_mychal.hf_val, {
52c03a2a	335	"Challenge", "tripe.kx.mychal.val",
	336	FT_BYTES, BASE_NONE, 0, 0,
	337	"This is the value of the sender's challenge."
3cdc3f3a	338	} },
3cdc3f3a	339	{ &hf_tripe_kx_mychal.hfx_len, {
52c03a2a	340	"Challenge x length", "tripe.kx.mychal.x.len",
	341	FT_UINT16, BASE_DEC, 0, 0,
	342	"This is the length of the sender's challenge x-coordinate."
3cdc3f3a	343	} },
3cdc3f3a	344	{ &hf_tripe_kx_mychal.hfy_val, {
52c03a2a	345	"Challenge x value", "tripe.kx.mychal.x.val",
	346	FT_BYTES, BASE_NONE, 0, 0,
	347	"This is the value of the sender's challenge x-coordinate."
3cdc3f3a	348	} },
3cdc3f3a	349	{ &hf_tripe_kx_mychal.hfy_len, {
52c03a2a	350	"Challenge y length", "tripe.kx.mychal.y.len",
	351	FT_UINT16, BASE_DEC, 0, 0,
	352	"This is the length of the sender's challenge x-coordinate."
3cdc3f3a	353	} },
3cdc3f3a	354	{ &hf_tripe_kx_mychal.hfx_val, {
52c03a2a	355	"Challenge y value", "tripe.kx.mychal.y.val",
165db1a8	356	FT_BYTES, BASE_NONE, 0, 0,
52c03a2a	357	"This is the value of the sender's challenge x-coordinate."
3cdc3f3a	358	} },
3cdc3f3a	359	{ &hf_tripe_kx_mycookie, {
165db1a8	360	"Sender's hashed cookie", "tripe.kx.mycookie",
	361	FT_BYTES, BASE_NONE, 0, 0,
	362	"This is the hash of the sender's challenge."
3cdc3f3a	363	} },
3cdc3f3a	364	{ &hf_tripe_kx_yourcookie, {
165db1a8	365	"Recipient's hashed cookie", "tripe.kx.yourcookie",
	366	FT_BYTES, BASE_NONE, 0, 0,
	367	"This is the hash of the recipient's challenge."
3cdc3f3a	368	} },
3cdc3f3a	369	{ &hf_tripe_kx_check.hf, {
165db1a8	370	"Challenge check-value", "tripe.kx.check",
	371	FT_BYTES, BASE_NONE, 0, 0,
	372	"This is an encrypted check-value which proves that the sender "
	373	"knows the answer to the challenge, and that it is therefore honest."
3cdc3f3a	374	} },
3cdc3f3a	375	{ &hf_tripe_kx_check.hf_len, {
165db1a8	376	"Check-value length", "tripe.kx.check.len",
	377	FT_UINT16, BASE_DEC, 0, 0,
	378	"This is the length of the encrypted check-value."
3cdc3f3a	379	} },
3cdc3f3a	380	{ &hf_tripe_kx_check.hf_val, {
165db1a8	381	"Check-value data", "tripe.kx.check.val",
	382	FT_BYTES, BASE_NONE, 0, 0,
	383	"This is the actual encrypted check-value."
3cdc3f3a	384	} },
3cdc3f3a	385	{ &hf_tripe_huh, {
165db1a8	386	"Unknown data", "tripe.huh",
	387	FT_BYTES, BASE_NONE, 0, 0,
	388	"I don't know what's meant to appear here."
3cdc3f3a	389	} },
165db1a8	390	};
	391
	392	static gint *tts[] = {
	393	&tt_tripe,
	394	&tt_tripe_ct,
	395	&hf_tripe_kx_mychal.tt,
	396	&hf_tripe_kx_check.tt,
	397	};
	398
	399	proto_tripe = proto_register_protocol("TrIPE", "TrIPE", "tripe");
	400	proto_register_field_array(proto_tripe, hfs, array_length(hfs));
	401	proto_register_subtree_array(tts, array_length(tts));
b5c45da1	402
	403	mod = prefs_register_protocol(proto_tripe, prefcb);
	404	prefs_register_uint_preference(mod, "hashsz", "Hash length",
	405	"hash function output length (in octets)",
	406	10, &hashsz);
	407	prefs_register_uint_preference(mod, "tagsz", "MAC tag length",
	408	"MAC tag length (in octets)", 10, &tagsz);
	409	prefs_register_uint_preference(mod, "ivsz", "IV length",
	410	"block cipher initialization vector length"
	411	" (in octets)",
	412	10, &ivsz);
165db1a8	413	}
	414
	415	void proto_reg_handoff_tripe(void)
	416	{
	417	dissector_handle_t dh;
	418
	419	dh = create_dissector_handle(dissect_tripe, proto_tripe);
	420	dissector_add("udp.port", 22003, dh);
	421	}
	422
	423	G_MODULE_EXPORT void plugin_reg_handoff(void)
	424	{
	425	proto_reg_handoff_tripe();
	426	}
	427
3cdc3f3a	428	G_MODULE_EXPORT void plugin_register(void)
165db1a8	429	{
165db1a8	430	if (proto_tripe == -1)
	431	proto_register_tripe();
	432	}
	433
	434	/----- That's all, folks -------------------------------------------------/