epan/dissectors/packet-btsmp.c

   1 /* packet-btsmp.c
   2  * Routines for Bluetooth Security Manager Protocol dissection
   3  *
   4  * Copyright 2012, Allan M. Madsen <allan.m@madsen.dk>
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * Wireshark - Network traffic analyzer
  13  * By Gerald Combs <gerald@wireshark.org>
  14  * Copyright 1998 Gerald Combs
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version 2
  19  * of the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  29  */
  30
  31 #include "config.h"
  32
  33 #include <epan/packet.h>
  34 #include "packet-btl2cap.h"
  35
  36 /* Initialize the protocol and registered fields */
  37 static int proto_btsmp = -1;
  38
  39 static int hf_btsmp_opcode = -1;
  40 static int hf_btsmp_io_capabilities = -1;
  41 static int hf_btsmp_oob_data_flags = -1;
  42 static int hf_btsmp_reason = -1;
  43 static int hf_btsmp_cfm_value = -1;
  44 static int hf_btsmp_random = -1;
  45 static int hf_btsmp_long_term_key = -1;
  46 static int hf_btsmp_id_resolving_key = -1;
  47 static int hf_btsmp_signature_key = -1;
  48 static int hf_btsmp_bonding_flags = -1;
  49 static int hf_btsmp_mitm_flag = -1;
  50 static int hf_btsmp_max_enc_key_size = -1;
  51 static int hf_btsmp_key_dist_enc = -1;
  52 static int hf_btsmp_key_dist_id = -1;
  53 static int hf_btsmp_key_dist_sign = -1;
  54 static int hf_btsmp_ediv = -1;
  55 static int hf_btsmp_authreq = -1;
  56 static int hf_btsmp_initiator_key_distribution = -1;
  57 static int hf_btsmp_responder_key_distribution = -1;
  58
  59 /* Initialize the subtree pointers */
  60 static gint ett_btsmp = -1;
  61 static gint ett_btsmp_auth_req = -1;
  62 static gint ett_btsmp_key_dist = -1;
  63
  64 /* Opcodes */
  65 static const value_string opcode_vals[] = {
  66     {0x01, "Pairing Request"},
  67     {0x02, "Pairing Response"},
  68     {0x03, "Pairing Confirm"},
  69     {0x04, "Pairing Random"},
  70     {0x05, "Pairing Failed"},
  71     {0x06, "Encryption Information"},
  72     {0x07, "Master Identification"},
  73     {0x08, "Identity Information"},
  74     {0x09, "Identity Address Information"},
  75     {0x0a, "Signing Information"},
  76     {0x0b, "Security Request"},
  77     {0x0, NULL}
  78 };
  79
  80 /* IO capabilities */
  81 static const value_string io_capability_vals[] = {
  82     {0x00, "Display Only"},
  83     {0x01, "Display Yes/No"},
  84     {0x02, "Keyboard Only"},
  85     {0x03, "No Input, No Output"},
  86     {0x04, "Keyboard, Display"},
  87     {0x0, NULL}
  88 };
  89
  90 /* OOB Data present Flag */
  91 static const value_string oob_data_flag_vals[] = {
  92     {0x00, "OOB Auth. Data Not Present"},
  93     {0x01, "OOB Auth. Data From Remote Device Present"},
  94     {0x0, NULL}
  95 };
  96
  97 /* Bonding flags */
  98 static const value_string bonding_flag_vals[] = {
  99     {0x00, "No Bonding"},
 100     {0x01, "Bonding"},
 101     {0x0, NULL}
 102 };
 103
 104 /* Reason codes */
 105 static const value_string reason_vals[] = {
 106     {0x01, "Passkey Entry Failed"},
 107     {0x02, "OOB Not Available"},
 108     {0x03, "Authentication Requirements"},
 109     {0x04, "Confirm Value Failed"},
 110     {0x05, "Pairing Not Supported"},
 111     {0x06, "Encryption Key Size"},
 112     {0x07, "Command Not Supported"},
 113     {0x08, "Unspecified Reason"},
 114     {0x09, "Repeated Attempts"},
 115     {0x0a, "Invalid Parameters"},
 116     {0x0, NULL}
 117 };
 118
 119 void proto_register_btsmp(void);
 120 void proto_reg_handoff_btsmp(void);
 121
 122 static int
 123 dissect_btsmp_auth_req(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
 124 {
 125     proto_item *ti_param;
 126     proto_tree *st_param;
 127     guint8 param;
 128
 129     param = tvb_get_guint8(tvb, offset);
 130     ti_param = proto_tree_add_item(tree, hf_btsmp_authreq, tvb, offset, 1, ENC_NA);
 131     st_param = proto_item_add_subtree(ti_param, ett_btsmp_auth_req);
 132     proto_tree_add_item(st_param, hf_btsmp_bonding_flags, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 133     proto_item_append_text(ti_param, "%s, ", val_to_str_const(param & 0x03, bonding_flag_vals, "<unknown>"));
 134     proto_tree_add_item(st_param, hf_btsmp_mitm_flag, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 135     proto_item_append_text(ti_param, "%s", (param & 0x04) ? "MITM" : "No MITM");
 136
 137     col_append_fstr(pinfo->cinfo, COL_INFO, "%s, %s", val_to_str_const(param & 0x03, bonding_flag_vals, "<unknown>"), (param & 0x04) ? "MITM" : "No MITM");
 138
 139     return offset + 1;
 140 }
 141
 142 static int
 143 dissect_btsmp_key_dist(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, gboolean initiator)
 144 {
 145     proto_item *ti_param;
 146     proto_tree *st_param;
 147     guint8 param;
 148
 149     param = tvb_get_guint8(tvb, offset);
 150     if (initiator) {
 151         col_append_str(pinfo->cinfo, COL_INFO, ", Initiator Key(s): ");
 152         ti_param = proto_tree_add_item(tree, hf_btsmp_initiator_key_distribution, tvb, offset, 1, ENC_NA);
 153     }
 154     else {
 155         col_append_str(pinfo->cinfo, COL_INFO, ", Responder Key(s): ");
 156         ti_param = proto_tree_add_item(tree, hf_btsmp_responder_key_distribution, tvb, offset, 1, ENC_NA);
 157     }
 158
 159     st_param = proto_item_add_subtree(ti_param, ett_btsmp_key_dist);
 160     proto_tree_add_item(st_param, hf_btsmp_key_dist_enc, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 161     proto_tree_add_item(st_param, hf_btsmp_key_dist_id, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 162     proto_tree_add_item(st_param, hf_btsmp_key_dist_sign, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 163     if (param & 0x01) {
 164         proto_item_append_text(ti_param, "LTK ");
 165         col_append_str(pinfo->cinfo, COL_INFO, "LTK ");
 166     }
 167     if (param & 0x02) {
 168         proto_item_append_text(ti_param, "IRK ");
 169         col_append_str(pinfo->cinfo, COL_INFO, "IRK ");
 170     }
 171     if (param & 0x04) {
 172         proto_item_append_text(ti_param, "CSRK ");
 173         col_append_str(pinfo->cinfo, COL_INFO, "CSRK ");
 174     }
 175
 176     return offset + 1;
 177 }
 178
 179 static int
 180 dissect_btsmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
 181 {
 182     int offset = 0;
 183     proto_item *ti;
 184     proto_tree *st;
 185     guint8 opcode;
 186
 187     ti = proto_tree_add_item(tree, proto_btsmp, tvb, 0, -1, ENC_NA);
 188     st = proto_item_add_subtree(ti, ett_btsmp);
 189
 190     col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMP");
 191
 192     switch (pinfo->p2p_dir) {
 193         case P2P_DIR_SENT:
 194             col_set_str(pinfo->cinfo, COL_INFO, "Sent ");
 195             break;
 196         case P2P_DIR_RECV:
 197             col_set_str(pinfo->cinfo, COL_INFO, "Rcvd ");
 198             break;
 199         default:
 200             col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown direction %d ",
 201                 pinfo->p2p_dir);
 202             break;
 203     }
 204
 205     if (tvb_length_remaining(tvb, 0) < 1)
 206         return FALSE;
 207
 208     proto_tree_add_item(st, hf_btsmp_opcode, tvb, 0, 1, ENC_LITTLE_ENDIAN);
 209     opcode = tvb_get_guint8(tvb, 0);
 210     offset++;
 211
 212     col_append_str(pinfo->cinfo, COL_INFO, val_to_str_const(opcode, opcode_vals, "<unknown>"));
 213
 214     switch (opcode) {
 215     case 0x01: /* Pairing Request */
 216     case 0x02: /* Pairing Response */
 217     {
 218         col_append_str(pinfo->cinfo, COL_INFO, ": ");
 219
 220         proto_tree_add_item(st, hf_btsmp_io_capabilities, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 221         offset++;
 222         proto_tree_add_item(st, hf_btsmp_oob_data_flags, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 223         offset++;
 224
 225         offset = dissect_btsmp_auth_req(tvb, offset, pinfo, st);
 226
 227         proto_tree_add_item(st, hf_btsmp_max_enc_key_size, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 228         offset++;
 229
 230         offset = dissect_btsmp_key_dist(tvb, offset, pinfo, st, TRUE);
 231         offset = dissect_btsmp_key_dist(tvb, offset, pinfo, st, FALSE);
 232         break;
 233     }
 234
 235     case 0x03: /* Pairing Confirm */
 236         proto_tree_add_item(st, hf_btsmp_cfm_value, tvb, offset, 16, ENC_NA);
 237         offset += 16;
 238         break;
 239
 240     case 0x04: /* Pairing Random */
 241         proto_tree_add_item(st, hf_btsmp_random, tvb, offset, 16, ENC_NA);
 242         offset += 16;
 243         break;
 244
 245     case 0x05: /* Pairing Failed */
 246         proto_tree_add_item(st, hf_btsmp_reason, tvb, offset, 1, ENC_LITTLE_ENDIAN);
 247         col_append_fstr(pinfo->cinfo, COL_INFO, ": %s", val_to_str_const(tvb_get_guint8(tvb, offset), reason_vals, "<unknown>"));
 248         offset++;
 249         break;
 250
 251     case 0x06: /* Encryption Information */
 252         proto_tree_add_item(st, hf_btsmp_long_term_key, tvb, offset, 16, ENC_NA);
 253         offset += 16;
 254         break;
 255
 256     case 0x07: /* Master Identification */
 257         proto_tree_add_item(st, hf_btsmp_ediv, tvb, offset, 2, ENC_LITTLE_ENDIAN);
 258         offset += 2;
 259         proto_tree_add_item(st, hf_btsmp_random, tvb, offset, 8, ENC_NA);
 260         offset += 8;
 261         break;
 262
 263     case 0x08: /* Identity Information */
 264         proto_tree_add_item(st, hf_btsmp_id_resolving_key, tvb, offset, 16, ENC_NA);
 265         offset += 16;
 266         break;
 267
 268     case 0x0a: /* Signing Informationn */
 269         proto_tree_add_item(st, hf_btsmp_signature_key, tvb, offset, 16, ENC_NA);
 270         offset += 16;
 271         break;
 272
 273      case 0x0b: /* Security Request */
 274         col_append_str(pinfo->cinfo, COL_INFO, ": ");
 275         offset = dissect_btsmp_auth_req(tvb, offset, pinfo, st);
 276         break;
 277
 278     default:
 279         break;
 280     }
 281
 282     return offset;
 283 }
 284
 285 void
 286 proto_register_btsmp(void)
 287 {
 288     static hf_register_info hf[] = {
 289         {&hf_btsmp_opcode,
 290             {"Opcode", "btsmp.opcode",
 291             FT_UINT8, BASE_HEX, VALS(opcode_vals), 0x0,
 292             NULL, HFILL}
 293         },
 294         {&hf_btsmp_reason,
 295             {"Reason", "btsmp.reason",
 296             FT_UINT8, BASE_HEX, VALS(reason_vals), 0x0,
 297             NULL, HFILL}
 298         },
 299         {&hf_btsmp_io_capabilities,
 300             {"IO Capability", "btsmp.io_capability",
 301             FT_UINT8, BASE_HEX, VALS(io_capability_vals), 0x0,
 302             NULL, HFILL}
 303         },
 304         {&hf_btsmp_oob_data_flags,
 305             {"OOB Data Flags", "btsmp.oob_data_flags",
 306             FT_UINT8, BASE_HEX, VALS(oob_data_flag_vals), 0x0,
 307             NULL, HFILL}
 308         },
 309         {&hf_btsmp_cfm_value,
 310             {"Confirm Value", "btsmp.cfm_value",
 311             FT_BYTES, BASE_NONE, NULL, 0x0,
 312             NULL, HFILL}
 313         },
 314         {&hf_btsmp_random,
 315             {"Random Value", "btsmp.random_value",
 316             FT_BYTES, BASE_NONE, NULL, 0x0,
 317             NULL, HFILL}
 318         },
 319         {&hf_btsmp_long_term_key,
 320             {"Long Term Key", "btsmp.long_term_key",
 321             FT_BYTES, BASE_NONE, NULL, 0x0,
 322             NULL, HFILL}
 323         },
 324         {&hf_btsmp_id_resolving_key,
 325             {"Identity Resolving Key", "btsmp.id_resolving_key",
 326             FT_BYTES, BASE_NONE, NULL, 0x0,
 327             NULL, HFILL}
 328         },
 329         {&hf_btsmp_signature_key,
 330             {"Signature Key", "btsmp.signature_key",
 331             FT_BYTES, BASE_NONE, NULL, 0x0,
 332             NULL, HFILL}
 333         },
 334         {&hf_btsmp_bonding_flags,
 335             {"Bonding Flags", "btsmp.bonding_flags",
 336             FT_UINT8, BASE_HEX, VALS(bonding_flag_vals), 0x03,
 337             NULL, HFILL}
 338         },
 339         {&hf_btsmp_mitm_flag,
 340             {"MITM Flag", "btsmp.mitm_flag",
 341             FT_UINT8, BASE_DEC, NULL, 0x04,
 342             NULL, HFILL}
 343         },
 344         {&hf_btsmp_max_enc_key_size,
 345             {"Max Encryption Key Size", "btsmp.max_enc_key_size",
 346             FT_UINT8, BASE_DEC, NULL, 0x00,
 347             NULL, HFILL}
 348         },
 349         {&hf_btsmp_key_dist_enc,
 350             {"Encryption Key (LTK)", "btsmp.key_dist_enc",
 351             FT_UINT8, BASE_DEC, NULL, 0x01,
 352             NULL, HFILL}
 353         },
 354         {&hf_btsmp_key_dist_id,
 355             {"Id Key (IRK)", "btsmp.key_dist_id",
 356             FT_UINT8, BASE_DEC, NULL, 0x02,
 357             NULL, HFILL}
 358         },
 359         {&hf_btsmp_key_dist_sign,
 360             {"Signature Key (CSRK)", "btsmp.key_dist_sign",
 361             FT_UINT8, BASE_DEC, NULL, 0x04,
 362             NULL, HFILL}
 363         },
 364         {&hf_btsmp_ediv,
 365             {"Encrypted Diversifier (EDIV)", "btsmp.ediv",
 366             FT_UINT16, BASE_HEX, NULL, 0x00,
 367             NULL, HFILL}
 368         },
 369         {&hf_btsmp_authreq,
 370             {"AuthReq", "btsmp.authreq",
 371             FT_NONE, BASE_NONE, NULL, 0x00,
 372             NULL, HFILL}
 373         },
 374         {&hf_btsmp_initiator_key_distribution,
 375             {"Initiator Key Distribution", "btsmp.initiator_key_distribution",
 376             FT_NONE, BASE_NONE, NULL, 0x00,
 377             NULL, HFILL}
 378         },
 379         {&hf_btsmp_responder_key_distribution,
 380             {"Responder Key Distribution", "btsmp.responder_key_distribution",
 381             FT_NONE, BASE_NONE, NULL, 0x00,
 382             NULL, HFILL}
 383         }
 384     };
 385
 386     /* Setup protocol subtree array */
 387     static gint *ett[] = {
 388       &ett_btsmp,
 389       &ett_btsmp_auth_req,
 390       &ett_btsmp_key_dist
 391     };
 392
 393     /* Register the protocol name and description */
 394     proto_btsmp = proto_register_protocol("Bluetooth Security Manager Protocol",
 395         "BT SMP", "btsmp");
 396
 397     new_register_dissector("btsmp", dissect_btsmp, proto_btsmp);
 398
 399     /* Required function calls to register the header fields and subtrees used */
 400     proto_register_field_array(proto_btsmp, hf, array_length(hf));
 401     proto_register_subtree_array(ett, array_length(ett));
 402 }
 403
 404 void
 405 proto_reg_handoff_btsmp(void)
 406 {
 407     dissector_handle_t btsmp_handle;
 408
 409     btsmp_handle = find_dissector("btsmp");
 410     dissector_add_uint("btl2cap.cid", BTL2CAP_FIXED_CID_SMP, btsmp_handle);
 411 }
 412
 413 /*
 414  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 415  *
 416  * Local variables:
 417  * c-basic-offset: 4
 418  * tab-width: 8
 419  * indent-tabs-mode: nil
 420  * End:
 421  *
 422  * vi: set shiftwidth=4 tabstop=8 expandtab:
 423  * :indentSize=4:tabSize=8:noTabs=true:
 424  */