packet-tacacs.c

   1 /* packet-tacacs.c
   2  * Routines for cisco tacacs/xtacacs/tacacs+ packet dissection
   3  * Copyright 2001, Paul Ionescu <paul@acorp.ro>
   4  *
   5  * $Id: packet-tacacs.c,v 1.23 2002/08/28 21:00:35 jmayer Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * Copied from old packet-tacacs.c
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version 2
  16  * of the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  26  */
  27
  28
  29 /* rfc-1492 for tacacs and xtacacs
  30  * draft-grant-tacacs-00.txt for tacacs+ (tacplus)
  31  */
  32
  33 #ifdef HAVE_CONFIG_H
  34 # include "config.h"
  35 #endif
  36
  37 #include <stdio.h>
  38
  39 #include <string.h>
  40 #include <glib.h>
  41 #include <epan/packet.h>
  42
  43 static int proto_tacacs = -1;
  44 static int hf_tacacs_version = -1;
  45 static int hf_tacacs_type = -1;
  46 static int hf_tacacs_nonce = -1;
  47 static int hf_tacacs_userlen = -1;
  48 static int hf_tacacs_passlen = -1;
  49 static int hf_tacacs_response = -1;
  50 static int hf_tacacs_reason = -1;
  51 static int hf_tacacs_result1 = -1;
  52 static int hf_tacacs_destaddr = -1;
  53 static int hf_tacacs_destport = -1;
  54 static int hf_tacacs_line = -1;
  55 static int hf_tacacs_result2 = -1;
  56 static int hf_tacacs_result3 = -1;
  57
  58 static gint ett_tacacs = -1;
  59
  60 #define VERSION_TACACS  0x00
  61 #define VERSION_XTACACS 0x80
  62
  63 static const value_string tacacs_version_vals[] = {
  64         { VERSION_TACACS,  "TACACS" },
  65         { VERSION_XTACACS, "XTACACS" },
  66         { 0,               NULL }
  67 };
  68
  69 #define TACACS_LOGIN            1
  70 #define TACACS_RESPONSE         2
  71 #define TACACS_CHANGE           3
  72 #define TACACS_FOLLOW           4
  73 #define TACACS_CONNECT          5
  74 #define TACACS_SUPERUSER        6
  75 #define TACACS_LOGOUT           7
  76 #define TACACS_RELOAD           8
  77 #define TACACS_SLIP_ON          9
  78 #define TACACS_SLIP_OFF         10
  79 #define TACACS_SLIP_ADDR        11
  80 static const value_string tacacs_type_vals[] = {
  81         { TACACS_LOGIN,     "Login" },
  82         { TACACS_RESPONSE,  "Response" },
  83         { TACACS_CHANGE,    "Change" },
  84         { TACACS_FOLLOW,    "Follow" },
  85         { TACACS_CONNECT,   "Connect" },
  86         { TACACS_SUPERUSER, "Superuser" },
  87         { TACACS_LOGOUT,    "Logout" },
  88         { TACACS_RELOAD,    "Reload" },
  89         { TACACS_SLIP_ON,   "SLIP on" },
  90         { TACACS_SLIP_OFF,  "SLIP off" },
  91         { TACACS_SLIP_ADDR, "SLIP Addr" },
  92         { 0,                NULL }};
  93
  94 static const value_string tacacs_reason_vals[] = {
  95         { 0  , "none" },
  96         { 1  , "expiring" },
  97         { 2  , "password" },
  98         { 3  , "denied" },
  99         { 4  , "quit" },
 100         { 5  , "idle" },
 101         { 6  , "drop" },
 102         { 7  , "bad" },
 103         { 0  , NULL }
 104 };
 105
 106 static const value_string tacacs_resp_vals[] = {
 107         { 0  , "this is not a response" },
 108         { 1  , "accepted" },
 109         { 2  , "rejected" },
 110         { 0  , NULL }
 111 };
 112
 113 #define TAC_PLUS_AUTHEN 1
 114 #define TAC_PLUS_AUTHOR 2
 115 #define TAC_PLUS_ACCT   3
 116
 117 #define UDP_PORT_TACACS 49
 118 #define TCP_PORT_TACACS 49
 119
 120 static void
 121 dissect_tacacs(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 122 {
 123         proto_tree      *tacacs_tree;
 124         proto_item      *ti;
 125         guint8          txt_buff[256],version,type,userlen,passlen;
 126
 127         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 128                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "TACACS");
 129         if (check_col(pinfo->cinfo, COL_INFO))
 130                 col_clear(pinfo->cinfo, COL_INFO);
 131
 132         version = tvb_get_guint8(tvb,0);
 133         if (version != 0) {
 134                 if (check_col(pinfo->cinfo, COL_PROTOCOL))
 135                         col_set_str(pinfo->cinfo, COL_PROTOCOL, "XTACACS");
 136         }
 137
 138         type = tvb_get_guint8(tvb,1);
 139         if (check_col(pinfo->cinfo, COL_INFO))
 140                 col_add_str(pinfo->cinfo, COL_INFO,
 141                     val_to_str(type, tacacs_type_vals, "Unknown (0x%02x)"));
 142
 143         if (tree)
 144         {
 145                 ti = proto_tree_add_protocol_format(tree, proto_tacacs,
 146                  tvb, 0, -1, version==0?"TACACS":"XTACACS");
 147                 tacacs_tree = proto_item_add_subtree(ti, ett_tacacs);
 148
 149                 proto_tree_add_uint(tacacs_tree, hf_tacacs_version, tvb, 0, 1,
 150                     version);
 151                 proto_tree_add_uint(tacacs_tree, hf_tacacs_type, tvb, 1, 1,
 152                     type);
 153                 proto_tree_add_item(tacacs_tree, hf_tacacs_nonce, tvb, 2, 2,
 154                     FALSE);
 155
 156         if (version==0)
 157             {
 158             if (type!=TACACS_RESPONSE)
 159                 {
 160                 userlen=tvb_get_guint8(tvb,4);
 161                 proto_tree_add_uint(tacacs_tree, hf_tacacs_userlen, tvb, 4, 1,
 162                     userlen);
 163                 passlen=tvb_get_guint8(tvb,5);
 164                 proto_tree_add_uint(tacacs_tree, hf_tacacs_passlen, tvb, 5, 1,
 165                     passlen);
 166                 tvb_get_nstringz0(tvb,6,userlen,txt_buff);
 167                 proto_tree_add_text(tacacs_tree, tvb, 6, userlen,         "Username: %s",txt_buff);
 168                 tvb_get_nstringz0(tvb,6+userlen,passlen,txt_buff);
 169                 proto_tree_add_text(tacacs_tree, tvb, 6+userlen, passlen, "Password: %s",txt_buff);
 170                 }
 171             else
 172                 {
 173                 proto_tree_add_item(tacacs_tree, hf_tacacs_response, tvb, 4, 1,
 174                     FALSE);
 175                 proto_tree_add_item(tacacs_tree, hf_tacacs_reason, tvb, 5, 1,
 176                     FALSE);
 177                 }
 178             }
 179         else
 180             {
 181             userlen=tvb_get_guint8(tvb,4);
 182             proto_tree_add_uint(tacacs_tree, hf_tacacs_userlen, tvb, 4, 1,
 183                 userlen);
 184             passlen=tvb_get_guint8(tvb,5);
 185             proto_tree_add_uint(tacacs_tree, hf_tacacs_passlen, tvb, 5, 1,
 186                 passlen);
 187             proto_tree_add_item(tacacs_tree, hf_tacacs_response, tvb, 6, 1,
 188                 FALSE);
 189             proto_tree_add_item(tacacs_tree, hf_tacacs_reason, tvb, 7, 1,
 190                 FALSE);
 191             proto_tree_add_item(tacacs_tree, hf_tacacs_result1, tvb, 8, 4,
 192                 FALSE);
 193             proto_tree_add_item(tacacs_tree, hf_tacacs_destaddr, tvb, 12, 4,
 194                 FALSE);
 195             proto_tree_add_item(tacacs_tree, hf_tacacs_destport, tvb, 16, 2,
 196                 FALSE);
 197             proto_tree_add_item(tacacs_tree, hf_tacacs_line, tvb, 18, 2,
 198                 FALSE);
 199             proto_tree_add_item(tacacs_tree, hf_tacacs_result2, tvb, 20, 4,
 200                 FALSE);
 201             proto_tree_add_item(tacacs_tree, hf_tacacs_result3, tvb, 24, 2,
 202                 FALSE);
 203             if (type!=TACACS_RESPONSE)
 204                 {
 205                 tvb_get_nstringz0(tvb,26,userlen,txt_buff);
 206                 proto_tree_add_text(tacacs_tree, tvb, 26, userlen,  "Username: %s",txt_buff);
 207                 tvb_get_nstringz0(tvb,26+userlen,passlen,txt_buff);
 208                 proto_tree_add_text(tacacs_tree, tvb, 26+userlen, passlen, "Password; %s",txt_buff);
 209                 }
 210             }
 211         }
 212 }
 213
 214 void
 215 proto_register_tacacs(void)
 216 {
 217         static hf_register_info hf[] = {
 218           { &hf_tacacs_version,
 219             { "Version",           "tacacs.version",
 220               FT_UINT8, BASE_HEX, VALS(tacacs_version_vals), 0x0,
 221               "Version", HFILL }},
 222           { &hf_tacacs_type,
 223             { "Type",              "tacacs.type",
 224               FT_UINT8, BASE_DEC, VALS(tacacs_type_vals), 0x0,
 225               "Type", HFILL }},
 226           { &hf_tacacs_nonce,
 227             { "Nonce",             "tacacs.nonce",
 228               FT_UINT16, BASE_HEX, NULL, 0x0,
 229               "Nonce", HFILL }},
 230           { &hf_tacacs_userlen,
 231             { "Username length",   "tacacs.userlen",
 232               FT_UINT8, BASE_DEC, NULL, 0x0,
 233               "Username length", HFILL }},
 234           { &hf_tacacs_passlen,
 235             { "Password length",   "tacacs.passlen",
 236               FT_UINT8, BASE_DEC, NULL, 0x0,
 237               "Password length", HFILL }},
 238           { &hf_tacacs_response,
 239             { "Response",          "tacacs.response",
 240               FT_UINT8, BASE_DEC, VALS(tacacs_resp_vals), 0x0,
 241               "Response", HFILL }},
 242           { &hf_tacacs_reason,
 243             { "Reason",            "tacacs.reason",
 244               FT_UINT8, BASE_DEC, VALS(tacacs_reason_vals), 0x0,
 245               "Reason", HFILL }},
 246           { &hf_tacacs_result1,
 247             { "Result 1",          "tacacs.result1",
 248               FT_UINT32, BASE_HEX, NULL, 0x0,
 249               "Result 1", HFILL }},
 250           { &hf_tacacs_destaddr,
 251             { "Destination address", "tacacs.destaddr",
 252               FT_IPv4, BASE_NONE, NULL, 0x0,
 253               "Destination address", HFILL }},
 254           { &hf_tacacs_destport,
 255             { "Destination port",  "tacacs.destport",
 256               FT_UINT16, BASE_DEC, NULL, 0x0,
 257               "Destination port", HFILL }},
 258           { &hf_tacacs_line,
 259             { "Line",              "tacacs.line",
 260               FT_UINT16, BASE_DEC, NULL, 0x0,
 261               "Line", HFILL }},
 262           { &hf_tacacs_result2,
 263             { "Result 2",          "tacacs.result2",
 264               FT_UINT32, BASE_HEX, NULL, 0x0,
 265               "Result 2", HFILL }},
 266           { &hf_tacacs_result3,
 267             { "Result 3",          "tacacs.result3",
 268               FT_UINT16, BASE_HEX, NULL, 0x0,
 269               "Result 3", HFILL }},
 270         };
 271
 272         static gint *ett[] = {
 273                 &ett_tacacs,
 274         };
 275         proto_tacacs = proto_register_protocol("TACACS", "TACACS", "tacacs");
 276         proto_register_field_array(proto_tacacs, hf, array_length(hf));
 277         proto_register_subtree_array(ett, array_length(ett));
 278 }
 279
 280 void
 281 proto_reg_handoff_tacacs(void)
 282 {
 283         dissector_handle_t tacacs_handle;
 284
 285         tacacs_handle = create_dissector_handle(dissect_tacacs, proto_tacacs);
 286         dissector_add("udp.port", UDP_PORT_TACACS, tacacs_handle);
 287 }
 288
 289 static int proto_tacplus = -1;
 290 static int hf_tacplus_response = -1;
 291 static int hf_tacplus_request = -1;
 292 static int hf_tacplus_majvers = -1;
 293 static int hf_tacplus_minvers = -1;
 294 static int hf_tacplus_type = -1;
 295 static int hf_tacplus_seqno = -1;
 296 static int hf_tacplus_flags = -1;
 297 static int hf_tacplus_flags_payload_type = -1;
 298 static int hf_tacplus_flags_connection_type = -1;
 299 static int hf_tacplus_session_id = -1;
 300 static int hf_tacplus_packet_len = -1;
 301
 302 static gint ett_tacplus = -1;
 303 static gint ett_tacplus_flags = -1;
 304
 305 static const value_string tacplus_type_vals[] = {
 306         { TAC_PLUS_AUTHEN  , "Authentication" },
 307         { TAC_PLUS_AUTHOR  , "Authorization" },
 308         { TAC_PLUS_ACCT    , "Accounting" },
 309         { 0 , NULL }};
 310
 311 #define FLAGS_UNENCRYPTED       0x01
 312
 313 static const true_false_string payload_type = {
 314   "Unencrypted",
 315   "Encrypted"
 316 };
 317
 318 #define FLAGS_SINGLE            0x04
 319
 320 static const true_false_string connection_type = {
 321   "Single",
 322   "Multiple"
 323 };
 324
 325 static void
 326 dissect_tacplus(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 327 {
 328         proto_tree      *tacplus_tree;
 329         proto_item      *ti;
 330         guint8          version,flags;
 331         proto_tree      *flags_tree;
 332         proto_item      *tf;
 333         guint32         len;
 334         gboolean        request=(pinfo->match_port == pinfo->destport);
 335
 336         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 337                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "TACACS+");
 338
 339         if (check_col(pinfo->cinfo, COL_INFO))
 340         {
 341                 col_set_str(pinfo->cinfo, COL_INFO,
 342                         request ? "Request" : "Response");
 343         }
 344
 345         if (tree)
 346         {
 347                 ti = proto_tree_add_protocol_format(tree, proto_tacplus,
 348                  tvb, 0, -1, "TACACS+");
 349
 350                 tacplus_tree = proto_item_add_subtree(ti, ett_tacplus);
 351                 if (pinfo->match_port == pinfo->destport)
 352                 {
 353                         proto_tree_add_boolean_hidden(tacplus_tree,
 354                             hf_tacplus_request, tvb, 0, 0, TRUE);
 355                 }
 356                 else
 357                 {
 358                         proto_tree_add_boolean_hidden(tacplus_tree,
 359                             hf_tacplus_response, tvb, 0, 0, TRUE);
 360                 }
 361                 version = tvb_get_guint8(tvb,0);
 362                 proto_tree_add_uint_format(tacplus_tree, hf_tacplus_majvers, tvb, 0, 1,
 363                     version,
 364                     "Major version: %s",
 365                     (version&0xf0)==0xc0?"TACACS+":"Unknown Version");
 366                 proto_tree_add_uint(tacplus_tree, hf_tacplus_minvers, tvb, 0, 1,
 367                     version&0xf);
 368                 proto_tree_add_item(tacplus_tree, hf_tacplus_type, tvb, 1, 1,
 369                     FALSE);
 370                 proto_tree_add_item(tacplus_tree, hf_tacplus_seqno, tvb, 2, 1,
 371                     FALSE);
 372                 flags = tvb_get_guint8(tvb,3);
 373                 tf = proto_tree_add_uint_format(tacplus_tree, hf_tacplus_flags,
 374                     tvb, 3, 1, flags,
 375                     "Flags: %s, %s (0x%02x)",
 376                     (flags&FLAGS_UNENCRYPTED) ? "Unencrypted payload" :
 377                                                 "Encrypted payload",
 378                     (flags&FLAGS_SINGLE) ? "Single connection" :
 379                                            "Multiple Connections",
 380                     flags);
 381                 flags_tree = proto_item_add_subtree(tf, ett_tacplus_flags);
 382                 proto_tree_add_boolean(flags_tree, hf_tacplus_flags_payload_type,
 383                     tvb, 3, 1, flags);
 384                 proto_tree_add_boolean(flags_tree, hf_tacplus_flags_connection_type,
 385                     tvb, 3, 1, flags);
 386                 proto_tree_add_item(tacplus_tree, hf_tacplus_session_id, tvb, 4, 4,
 387                     FALSE);
 388                 len = tvb_get_ntohl(tvb,8);
 389                 proto_tree_add_uint(tacplus_tree, hf_tacplus_packet_len, tvb, 8, 4,
 390                     len);
 391
 392                 if (flags&FLAGS_UNENCRYPTED)
 393                         proto_tree_add_text(tacplus_tree, tvb, 12, len, "Payload");
 394                 else
 395                         proto_tree_add_text(tacplus_tree, tvb, 12, len, "Encrypted payload");
 396         }
 397 }
 398
 399 void
 400 proto_register_tacplus(void)
 401 {
 402         static hf_register_info hf[] = {
 403           { &hf_tacplus_response,
 404             { "Response",           "tacplus.response",
 405               FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 406               "TRUE if TACACS+ response", HFILL }},
 407           { &hf_tacplus_request,
 408             { "Request",            "tacplus.request",
 409               FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 410               "TRUE if TACACS+ request", HFILL }},
 411           { &hf_tacplus_majvers,
 412             { "Major version",      "tacplus.majvers",
 413               FT_UINT8, BASE_DEC, NULL, 0x0,
 414               "Major version number", HFILL }},
 415           { &hf_tacplus_minvers,
 416             { "Minor version",      "tacplus.minvers",
 417               FT_UINT8, BASE_DEC, NULL, 0x0,
 418               "Minor version number", HFILL }},
 419           { &hf_tacplus_type,
 420             { "Type",               "tacplus.type",
 421               FT_UINT8, BASE_DEC, VALS(tacplus_type_vals), 0x0,
 422               "Type", HFILL }},
 423           { &hf_tacplus_seqno,
 424             { "Sequence number",    "tacplus.seqno",
 425               FT_UINT8, BASE_DEC, NULL, 0x0,
 426               "Sequence number", HFILL }},
 427           { &hf_tacplus_flags,
 428             { "Flags",              "tacplus.flags",
 429               FT_UINT8, BASE_HEX, NULL, 0x0,
 430               "Flags", HFILL }},
 431           { &hf_tacplus_flags_payload_type,
 432             { "Payload type",       "tacplus.flags.payload_type",
 433               FT_BOOLEAN, 8, TFS(&payload_type), FLAGS_UNENCRYPTED,
 434               "Payload type (unencrypted or encrypted)", HFILL }},
 435           { &hf_tacplus_flags_connection_type,
 436             { "Connection type",    "tacplus.flags.connection_type",
 437               FT_BOOLEAN, 8, TFS(&connection_type), FLAGS_SINGLE,
 438               "Connection type (single or multiple)", HFILL }},
 439           { &hf_tacplus_session_id,
 440             { "Session ID",         "tacplus.session_id",
 441               FT_UINT32, BASE_DEC, NULL, 0x0,
 442               "Session ID", HFILL }},
 443           { &hf_tacplus_packet_len,
 444             { "Packet length",      "tacplus.packet_len",
 445               FT_UINT32, BASE_DEC, NULL, 0x0,
 446               "Packet length", HFILL }}
 447         };
 448
 449         static gint *ett[] = {
 450                 &ett_tacplus,
 451                 &ett_tacplus_flags,
 452         };
 453         proto_tacplus = proto_register_protocol("TACACS+", "TACACS+", "tacplus");
 454         proto_register_field_array(proto_tacplus, hf, array_length(hf));
 455         proto_register_subtree_array(ett, array_length(ett));
 456 }
 457
 458 void
 459 proto_reg_handoff_tacplus(void)
 460 {
 461         dissector_handle_t tacplus_handle;
 462
 463         tacplus_handle = create_dissector_handle(dissect_tacplus,
 464             proto_tacplus);
 465         dissector_add("tcp.port", TCP_PORT_TACACS, tacplus_handle);
 466 }