[tripe] / wireshark / packet-tripe.c

/* -*-c-*-
 *
 * $Id$
 *
 * TrIPE protocol dissector for Wireshark
 *
 * (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 <wireshark/config.h>
#include <wireshark/epan/packet.h>
#include <wireshark/epan/prefs.h>

#include "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_misc_type = -1;
static int hf_tripe_misc_payload = -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_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;
      case MSG_MISC:
	switch (ty & MSG_TYPEMASK) {
	  case MISC_NOP:
	    col_set_str(p->cinfo, COL_INFO, "Miscellaneous, no-operation");
	    break;
	  case MISC_PING:
	    col_set_str(p->cinfo, COL_INFO, "Miscellaneous, transport ping");
	    break;
	  case MISC_PONG:
	    col_set_str(p->cinfo, COL_INFO,
			"Miscellaneous, transport ping reply");
	    break;
	  case MISC_EPING:
	    col_set_str(p->cinfo, COL_INFO, "Miscellaneous, encrypted ping");
	    break;
	  case MISC_EPONG:
	    col_set_str(p->cinfo, COL_INFO,
			"Miscellaneous, encrypted ping reply");
	    break;
	  case MISC_GREET:
	    col_set_str(p->cinfo, COL_INFO,
			"Miscellaneous, greeting");
	    break;
	  default:
	    col_add_fstr(p->cinfo, COL_INFO,
			 "Miscellaneous, 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_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 = 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 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;
      case MSG_MISC:
	proto_tree_add_item(tt, hf_tripe_misc_type, b, 0, 1, FALSE);
	switch (ty & MSG_TYPEMASK) {
	  case MISC_NOP:
	  case MISC_PING:
	  case MISC_PONG:
	  case MISC_GREET:
	    proto_tree_add_item(tt, hf_tripe_misc_payload,
				b, off, -1, FALSE);
	    goto done;
	  case MISC_EPING:
	  case MISC_EPONG:
	    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_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_misc_type, {
      "Miscellaneous message type", "tripe.misc.type",
      FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
      "This is the TrIPE miscellaneous message type subcode."
    } },
    { &hf_tripe_misc_payload, {
      "Miscellaneous message payload", "tripe.misc.payload",
      FT_BYTES, BASE_NONE, 0, 0,
      "This is the miscellaneous message payload."
    } },
    { &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.hfx_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.hfy_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	*
28461f0e	5	* TrIPE protocol dissector for Wireshark
165db1a8	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>
28461f0e MW	41	#include <wireshark/config.h>
	42	#include <wireshark/epan/packet.h>
	43	#include <wireshark/epan/prefs.h>
165db1a8	44
78698994	45	#include "protocol.h"
165db1a8	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;
0ba8de86	67	static int hf_tripe_misc_type = -1;
0ba8de86	68	static int hf_tripe_misc_payload = -1;
165db1a8	69	static int hf_tripe_kx_type = -1;
52c03a2a	70	static hfge hf_tripe_kx_mychal = { -1, -1, -1, -1, -1, -1, -1, -1 };
165db1a8	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;
	75
	76	static int tt_tripe = -1;
	77	static int tt_tripe_ct = -1;
	78
	79	G_MODULE_EXPORT const gchar version[] = VERSION;
	80
	81	/----- Main code ---------------------------------------------------------/
	82
b5c45da1	83	static void prefcb(void) { }
b5c45da1	84
165db1a8	85	static gint gethash(proto_tree tt, int hf, tvbuff_t b, gint off)
165db1a8	86	{
b5c45da1	87	proto_tree_add_item(tt, hf, b, off, hashsz, FALSE);
b5c45da1	88	return (off + hashsz);
165db1a8	89	}
	90
	91	static gint getmp(proto_tree tt, const hfmp hf, tvbuff_t *b, gint off)
	92	{
	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);
	99	}
	100
52c03a2a	101	static gint getge(proto_tree tt, const hfge hf, tvbuff_t *b, gint off)
	102	{
	103	guint16 len = tvb_get_ntohs(b, off), len2;
	104	guint r;
	105	proto_item *ti;
	106	r = tvb_length_remaining(b, off);
	107	if (r < 4 + len \|\|
	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);
	113	r = off + len + 2;
	114	} else {
	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;
	122	}
	123	return (r);
	124	}
	125
165db1a8	126	static void dissect_tripe(tvbuff_t b, packet_info p, proto_tree *t)
	127	{
	128	proto_item *ti;
	129	proto_tree *tt;
	130	guint8 ty;
3cdc3f3a	131	gint off = 0;
165db1a8	132	guint32 seq;
	133
	134	/* --- Initialize the summary cells --- */
	135
	136	if (check_col(p->cinfo, COL_PROTOCOL))
	137	col_set_str(p->cinfo, COL_PROTOCOL, "TrIPE");
3cdc3f3a	138	if (check_col(p->cinfo, COL_INFO))
3cdc3f3a	139	col_clear(p->cinfo, COL_INFO);
165db1a8	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) {
	144	case MSG_PACKET:
	145	switch (ty & MSG_TYPEMASK) {
	146	case 0:
	147	col_set_str(p->cinfo, COL_INFO, "Packet data");
	148	break;
	149	default:
	150	col_add_fstr(p->cinfo, COL_INFO,
	151	"Packet data, unknown type code %u",
	152	ty & MSG_TYPEMASK);
	153	break;
	154	}
	155	break;
	156	case MSG_KEYEXCH:
	157	switch (ty & MSG_TYPEMASK) {
	158	case KX_PRECHAL:
	159	col_set_str(p->cinfo, COL_INFO, "Key exchange, prechallenge");
	160	break;
165db1a8	161	case KX_CHAL:
	162	col_set_str(p->cinfo, COL_INFO, "Key exchange, challenge");
	163	break;
	164	case KX_REPLY:
	165	col_set_str(p->cinfo, COL_INFO, "Key exchange, reply");
	166	break;
	167	case KX_SWITCH:
	168	col_set_str(p->cinfo, COL_INFO, "Key exchange, switch request");
	169	break;
	170	case KX_SWITCHOK:
	171	col_set_str(p->cinfo, COL_INFO, "Key exchange, switch response");
	172	break;
	173	default:
	174	col_add_fstr(p->cinfo, COL_INFO,
	175	"Key exchange, unknown type code %u",
	176	ty & MSG_TYPEMASK);
	177	break;
	178	}
	179	break;
0ba8de86	180	case MSG_MISC:
	181	switch (ty & MSG_TYPEMASK) {
	182	case MISC_NOP:
	183	col_set_str(p->cinfo, COL_INFO, "Miscellaneous, no-operation");
	184	break;
	185	case MISC_PING:
	186	col_set_str(p->cinfo, COL_INFO, "Miscellaneous, transport ping");
	187	break;
	188	case MISC_PONG:
	189	col_set_str(p->cinfo, COL_INFO,
	190	"Miscellaneous, transport ping reply");
	191	break;
	192	case MISC_EPING:
	193	col_set_str(p->cinfo, COL_INFO, "Miscellaneous, encrypted ping");
	194	break;
	195	case MISC_EPONG:
	196	col_set_str(p->cinfo, COL_INFO,
	197	"Miscellaneous, encrypted ping reply");
	198	break;
37941236	199	case MISC_GREET:
	200	col_set_str(p->cinfo, COL_INFO,
	201	"Miscellaneous, greeting");
	202	break;
0ba8de86	203	default:
	204	col_add_fstr(p->cinfo, COL_INFO,
	205	"Miscellaneous, unknown type code %u",
	206	ty & MSG_TYPEMASK);
	207	break;
	208	}
	209	break;
165db1a8	210	default:
	211	col_add_fstr(p->cinfo, COL_INFO,
	212	"Unknown category code %u, unknown type code %u",
	213	ty & MSG_CATMASK, ty & MSG_TYPEMASK);
	214	break;
	215	}
	216	}
	217
	218	/* --- Fill in the tree --- */
	219
	220	if (t) {
	221	ti = proto_tree_add_item(t, proto_tripe, b, 0, -1, FALSE);
	222	tt = proto_item_add_subtree(ti, tt_tripe);
	223
	224	proto_tree_add_item(tt, hf_tripe_cat, b, 0, 1, FALSE);
	225
	226	off = 1;
	227	switch (ty & MSG_CATMASK) {
	228	case MSG_PACKET:
	229	proto_tree_add_item(tt, hf_tripe_packet_type, b, 0, 1, FALSE);
	230	switch (ty & MSG_TYPEMASK) {
	231	case 0:
	232	goto ct;
	233	default:
	234	goto huh;
	235	}
	236	break;
	237	case MSG_KEYEXCH:
	238	proto_tree_add_item(tt, hf_tripe_kx_type, b, 0, 1, FALSE);
	239	switch (ty & MSG_TYPEMASK) {
	240	case KX_PRECHAL:
52c03a2a	241	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	242	goto tail;
165db1a8	243	case KX_CHAL:
52c03a2a	244	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	245	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	246	off = getmp(tt, &hf_tripe_kx_check, b, off);
	247	goto tail;
	248	case KX_REPLY:
28461f0e	249	off = getge(tt, &hf_tripe_kx_mychal, b, off);
165db1a8	250	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	251	off = getmp(tt, &hf_tripe_kx_check, b, off);
	252	goto ct;
	253	case KX_SWITCH:
	254	off = gethash(tt, hf_tripe_kx_mycookie, b, off);
	255	off = gethash(tt, hf_tripe_kx_yourcookie, b, off);
	256	goto ct;
	257	case KX_SWITCHOK:
	258	goto ct;
	259	default:
	260	goto huh;
	261	}
	262	break;
0ba8de86	263	case MSG_MISC:
	264	proto_tree_add_item(tt, hf_tripe_misc_type, b, 0, 1, FALSE);
	265	switch (ty & MSG_TYPEMASK) {
	266	case MISC_NOP:
	267	case MISC_PING:
	268	case MISC_PONG:
37941236	269	case MISC_GREET:
0ba8de86	270	proto_tree_add_item(tt, hf_tripe_misc_payload,
	271	b, off, -1, FALSE);
	272	goto done;
	273	case MISC_EPING:
	274	case MISC_EPONG:
	275	goto ct;
	276	default:
	277	goto huh;
	278	}
	279	break;
165db1a8	280	default:
	281	goto huh;
	282	}
	283	tail:
	284	if (tvb_offset_exists(b, off))
	285	goto huh;
	286	goto done;
	287	huh:
	288	proto_tree_add_item(tt, hf_tripe_huh, b, off, -1, FALSE);
	289	goto done;
	290	ct:
	291	ti = proto_tree_add_item(tt, hf_tripe_ct, b, off, -1, FALSE);
b5c45da1	292	seq = tvb_get_ntohl(b, off + tagsz);
165db1a8	293	proto_item_set_text(ti, "Encrypted ciphertext (sequence number %lu)",
	294	(unsigned long)seq);
	295	tt = proto_item_add_subtree(ti, tt_tripe_ct);
b5c45da1	296	if (tagsz) {
	297	proto_tree_add_item(tt, hf_tripe_ct_tag, b, off, tagsz, FALSE);
	298	off += tagsz;
	299	}
165db1a8	300	proto_tree_add_item(tt, hf_tripe_ct_seq, b, off, 4, FALSE);
165db1a8	301	off += 4;
b5c45da1	302	if (ivsz) {
	303	proto_tree_add_item(tt, hf_tripe_ct_iv, b, off, ivsz, FALSE);
	304	off += ivsz;
	305	}
	306	proto_tree_add_item(ti, hf_tripe_ct_ct, b, off, -1, FALSE);
165db1a8	307	goto done;
	308	done:;
	309	}
	310	}
	311
	312	void proto_register_tripe(void)
	313	{
b5c45da1	314	module_t *mod;
b5c45da1	315
165db1a8	316	static value_string vs_kxtype[] = {
165db1a8	317	{ KX_PRECHAL, "KX_PRECHAL (prechallenge)" },
165db1a8	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)" },
	322	{ 0, 0 }
	323	};
	324
	325	static hf_register_info hfs[] = {
3cdc3f3a	326	{ &hf_tripe_cat, {
165db1a8	327	"Message category", "tripe.cat",
165db1a8	328	FT_UINT8, BASE_HEX, 0, MSG_CATMASK
3cdc3f3a	329	} },
3cdc3f3a	330	{ &hf_tripe_packet_type, {
165db1a8	331	"Packet message type", "tripe.packet.type",
	332	FT_UINT8, BASE_HEX, 0, MSG_TYPEMASK,
	333	"This is the TrIPE packet type subcode."
3cdc3f3a	334	} },
3cdc3f3a	335	{ &hf_tripe_ct, {
165db1a8	336	"Encrypted ciphertext", "tripe.ct",
	337	FT_BYTES, BASE_NONE, 0, 0,
	338	"This is an encrypted message."
3cdc3f3a	339	} },
3cdc3f3a	340	{ &hf_tripe_ct_seq, {
165db1a8	341	"Ciphertext sequence number", "tripe.ct.seq",
	342	FT_UINT32, BASE_DEC, 0, 0,
	343	"This is the unique sequence number for the ciphertext."
3cdc3f3a	344	} },
3cdc3f3a	345	{ &hf_tripe_ct_iv, {
165db1a8	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."
3cdc3f3a	349	} },
3cdc3f3a	350	{ &hf_tripe_ct_ct, {
b5c45da1	351	"Actual encrypted data", "tripe.ct.ct",
165db1a8	352	FT_BYTES, BASE_NONE, 0, 0,
b5c45da1	353	"This is the encrypted message. Reading it ought to be hard."
3cdc3f3a	354	} },
3cdc3f3a	355	{ &hf_tripe_ct_tag, {
b5c45da1	356	"Message authentication code", "tripe.ct.tag",
165db1a8	357	FT_BYTES, BASE_NONE, 0, 0,
b5c45da1	358	"This is the message authentication code tag for the ciphertext."
3cdc3f3a	359	} },
0ba8de86	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."
	364	} },
	365	{ &hf_tripe_misc_payload, {
37941236	366	"Miscellaneous message payload", "tripe.misc.payload",
0ba8de86	367	FT_BYTES, BASE_NONE, 0, 0,
	368	"This is the miscellaneous message payload."
	369	} },
3cdc3f3a	370	{ &hf_tripe_kx_type, {
165db1a8	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."
3cdc3f3a	374	} },
3cdc3f3a	375	{ &hf_tripe_kx_mychal.hf, {
165db1a8	376	"Sender's challenge data", "tripe.kx.mychal",
165db1a8	377	FT_BYTES, BASE_NONE, 0, 0,
52c03a2a	378	"This is the sender's challenge."
3cdc3f3a	379	} },
3cdc3f3a	380	{ &hf_tripe_kx_mychal.hf_len, {
165db1a8	381	"Challenge length", "tripe.kx.mychal.len",
165db1a8	382	FT_UINT16, BASE_DEC, 0, 0,
52c03a2a	383	"This is the length of the sender's challenge."
3cdc3f3a	384	} },
3cdc3f3a	385	{ &hf_tripe_kx_mychal.hf_val, {
52c03a2a	386	"Challenge", "tripe.kx.mychal.val",
	387	FT_BYTES, BASE_NONE, 0, 0,
	388	"This is the value of the sender's challenge."
3cdc3f3a	389	} },
3cdc3f3a	390	{ &hf_tripe_kx_mychal.hfx_len, {
52c03a2a	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."
3cdc3f3a	394	} },
e94fafe4	395	{ &hf_tripe_kx_mychal.hfx_val, {
52c03a2a	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."
3cdc3f3a	399	} },
3cdc3f3a	400	{ &hf_tripe_kx_mychal.hfy_len, {
52c03a2a	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."
3cdc3f3a	404	} },
e94fafe4	405	{ &hf_tripe_kx_mychal.hfy_val, {
52c03a2a	406	"Challenge y value", "tripe.kx.mychal.y.val",
165db1a8	407	FT_BYTES, BASE_NONE, 0, 0,
52c03a2a	408	"This is the value of the sender's challenge x-coordinate."
3cdc3f3a	409	} },
3cdc3f3a	410	{ &hf_tripe_kx_mycookie, {
165db1a8	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."
3cdc3f3a	414	} },
3cdc3f3a	415	{ &hf_tripe_kx_yourcookie, {
165db1a8	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."
3cdc3f3a	419	} },
3cdc3f3a	420	{ &hf_tripe_kx_check.hf, {
165db1a8	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."
3cdc3f3a	425	} },
3cdc3f3a	426	{ &hf_tripe_kx_check.hf_len, {
165db1a8	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."
3cdc3f3a	430	} },
3cdc3f3a	431	{ &hf_tripe_kx_check.hf_val, {
165db1a8	432	"Check-value data", "tripe.kx.check.val",
	433	FT_BYTES, BASE_NONE, 0, 0,
	434	"This is the actual encrypted check-value."
3cdc3f3a	435	} },
3cdc3f3a	436	{ &hf_tripe_huh, {
165db1a8	437	"Unknown data", "tripe.huh",
	438	FT_BYTES, BASE_NONE, 0, 0,
	439	"I don't know what's meant to appear here."
3cdc3f3a	440	} },
165db1a8	441	};
	442
	443	static gint *tts[] = {
	444	&tt_tripe,
	445	&tt_tripe_ct,
	446	&hf_tripe_kx_mychal.tt,
	447	&hf_tripe_kx_check.tt,
	448	};
	449
	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));
b5c45da1	453
	454	mod = prefs_register_protocol(proto_tripe, prefcb);
	455	prefs_register_uint_preference(mod, "hashsz", "Hash length",
	456	"hash function output length (in octets)",
	457	10, &hashsz);
	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"
	462	" (in octets)",
	463	10, &ivsz);
165db1a8	464	}
	465
	466	void proto_reg_handoff_tripe(void)
	467	{
	468	dissector_handle_t dh;
	469
	470	dh = create_dissector_handle(dissect_tripe, proto_tripe);
	471	dissector_add("udp.port", 22003, dh);
	472	}
	473
	474	G_MODULE_EXPORT void plugin_reg_handoff(void)
	475	{
	476	proto_reg_handoff_tripe();
	477	}
	478
3cdc3f3a	479	G_MODULE_EXPORT void plugin_register(void)
165db1a8	480	{
165db1a8	481	if (proto_tripe == -1)
	482	proto_register_tripe();
	483	}
	484
	485	/----- That's all, folks -------------------------------------------------/