path: root/epan/dissectors/packet-wifi-dpp.c

/* packet-wifi-dpp.c
 *
 * Wi-Fi Device Provisioning Protocol (DPP)
 *
 * Copyright 2017 Richard Sharpe <realrichardsharpe@gmail.com>
 * Copyright 2017 The WiFi Alliance
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/*
 * Code and constants based on Wi-Fi_DPP_Tech_Spec_v0_1_5
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/to_str.h>
#include <epan/expert.h>

#include "packet-ieee80211.h"

void proto_register_wifi_dpp(void);
void proto_reg_handoff_wifi_dpp(void);

enum {
  DPP_STATUS_OK =                0,
  DPP_STATUS_NOT_COMPATIBLE =    1,
  DPP_STATUS_AUTH_FAILURE =      2,
  DPP_STATUS_UNWRAP_FAILURE =    3,
  DPP_STATUS_BAD_GROUP =         4,
  DPP_STATUS_CONFIGURE_FAILURE = 5,
  DPP_STATUS_RESPONSE_PENDING =  6
};

static const value_string dpp_status_codes[] = {
  { DPP_STATUS_OK,                "OK" },
  { DPP_STATUS_NOT_COMPATIBLE,    "Not Compatible" },
  { DPP_STATUS_AUTH_FAILURE,      "Auth Failure" },
  { DPP_STATUS_UNWRAP_FAILURE,    "Unwrap Failure" },
  { DPP_STATUS_BAD_GROUP,         "Bad Group" },
  { DPP_STATUS_CONFIGURE_FAILURE, "Configure Failure" },
  { DPP_STATUS_RESPONSE_PENDING,  "Response Pending" },
  { 0, NULL }
};

enum {
  DPP_STATUS                           = 0x1000,
  DPP_INITIATOR_BOOTSTRAPPING_KEY_HASH = 0x1001,
  DPP_RESPONDER_BOOTSTRAPPING_KEY_HASH = 0x1002,
  DPP_INITIATOR_PROTOCOL_KEY           = 0x1003,
  DPP_WRAPPED_DATA                     = 0x1004,
  DPP_INITIATOR_NONCE                  = 0x1005,
  DPP_INITIATOR_CAPABILITIES           = 0x1006,
  DPP_RESPONDER_NONCE                  = 0x1007,
  DPP_RESPONDER_CAPABILITIES           = 0x1008,
  DPP_RESPONDER_PROTOCOL_KEY           = 0x1009,
  DPP_INITIATOR_AUTHENTICATING_TAG     = 0x100A,
  DPP_RESPONDER_AUTHENTICATING_TAG     = 0x100B,
  DPP_CONFIGURATION_OBJECT             = 0x100C,
  DPP_CONNECTOR                        = 0x100D,
  DPP_CONFIGURATION_ATTRIBUTES_OBJECT  = 0x100E,
  DPP_BOOTSTRAPPING_KEY                = 0x100F,
  DPP_FINITE_CYCLIC_GROUP              = 0x1012,
  DPP_ENCRYPTED_KEY                    = 0x1013,
  DPP_ENROLLEE_NONCE                   = 0x1014,
  DPP_CODE_IDENTIFIER                  = 0x1015,
  DPP_TRANSACTION_ID                   = 0x1016
};

static const value_string dpp_ie_attr_ids[] = {
  { DPP_STATUS,                           "DPP Status" },
  { DPP_INITIATOR_BOOTSTRAPPING_KEY_HASH, "DPP Initiator Bootstrapping Key Hash" },
  { DPP_RESPONDER_BOOTSTRAPPING_KEY_HASH, "DPP Responder Bootstrapping Key Hash" },
  { DPP_INITIATOR_PROTOCOL_KEY,           "DPP Initiator Protocol Key" },
  { DPP_WRAPPED_DATA,                     "DPP Primary Wrapped Data" },
  { DPP_INITIATOR_NONCE,                  "DPP Initiator Nonce" },
  { DPP_INITIATOR_CAPABILITIES,           "DPP Initiator Capabilities" },
  { DPP_RESPONDER_NONCE,                  "DPP Responder Nonce" },
  { DPP_RESPONDER_CAPABILITIES,           "DPP Responder Capabilities" },
  { DPP_RESPONDER_PROTOCOL_KEY,           "DPP Responder Protocol Key" },
  { DPP_INITIATOR_AUTHENTICATING_TAG,     "DPP Initiator Authenticating Tag" },
  { DPP_RESPONDER_AUTHENTICATING_TAG,     "DPP Responder Authenticating Tag" },
  { DPP_CONFIGURATION_OBJECT,             "DPP Configuration Object" },
  { DPP_CONNECTOR,                        "DPP Connector" },
  { DPP_CONFIGURATION_ATTRIBUTES_OBJECT,  "DPP Configuration Attributes Object" },
  { DPP_BOOTSTRAPPING_KEY,                "DPP Bootstrapping Key" },
  { DPP_FINITE_CYCLIC_GROUP,              "DPP Finite Cyclic Group" },
  { DPP_ENCRYPTED_KEY,                    "DPP Encrypted Key" },
  { DPP_CODE_IDENTIFIER,                  "DPP Code Identifier" },
  { DPP_TRANSACTION_ID,                   "DPP Transaction ID" },
  { 0, NULL }
};

enum {
  DPP_AUTHENTICATION_REQUEST      = 0,
  DPP_AUTHENTICATION_RESPONSE     = 1,
  DPP_AUTHENTICATION_CONFIRM      = 2,
  DPP_PEER_DISCOVERY_REQUEST      = 5,
  DPP_PEER_DISCOVERY_RESPONSE     = 6,
  DPP_PKEX_EXCHANGE_REQUEST       = 7,
  DPP_PKEX_EXCHANGE_RESPONSE      = 8,
  DPP_PKEX_COMMIT_REVEAL_REQUEST  = 9,
  DPP_PKEX_COMMIT_REVEAL_RESPONSE = 10
};

static const value_string dpp_public_action_subtypes[] = {
  { DPP_AUTHENTICATION_REQUEST,      "Authentiation Request" },
  { DPP_AUTHENTICATION_RESPONSE,     "Authentication Response" },
  { DPP_AUTHENTICATION_CONFIRM,      "Authentication Confirm" },
  { DPP_PEER_DISCOVERY_REQUEST,      "Peer Discovery Request" },
  { DPP_PEER_DISCOVERY_RESPONSE,     "Peer Discovery Response" },
  { DPP_PKEX_EXCHANGE_REQUEST,       "PKEX Exchange Request" },
  { DPP_PKEX_EXCHANGE_RESPONSE,      "PKEX Exchange Response" },
  { DPP_PKEX_COMMIT_REVEAL_REQUEST,  "PKEX Commit-Reveal Request" },
  { DPP_PKEX_COMMIT_REVEAL_RESPONSE, "PKEX Commit-Reveal Response" },
  { 0, NULL }
};

/*
 * This table and the one above share values ... but this one is truncated.
 */
static const value_string dpp_action_subtypes[] = {
  { DPP_AUTHENTICATION_REQUEST, "Authentication Request" },
  { DPP_AUTHENTICATION_RESPONSE, "Authentication Response" },
  { DPP_AUTHENTICATION_CONFIRM, "Authentication Confirm" },
  { DPP_PEER_DISCOVERY_REQUEST, "Peer Discovery Request" },
  { DPP_PEER_DISCOVERY_RESPONSE, "Peer Discovery Response" },
  { 0, NULL }
};

static int proto_wifi_dpp = -1;

static gint ett_wifi_dpp_ie_generic = -1;
static gint ett_wifi_dpp_attributes = -1;
static gint ett_wifi_dpp_pa = -1;
static gint ett_wifi_dpp_attribute = -1;
static gint ett_wifi_dpp_attr_header = -1;

static int hf_wifi_dpp_ie_attr_id = -1;
static int hf_wifi_dpp_ie_attr_len = -1;
static int hf_wifi_dpp_ie_generic = -1;  /* Remove eventually */
static int hf_wifi_dpp_action_dialog_token = -1;
static int hf_wifi_dpp_action_subtype = -1;
static int hf_wifi_dpp_public_action_subtype = -1;
static int hf_wifi_dpp_status = -1;
static int hf_wifi_dpp_init_hash = -1;
static int hf_wifi_dpp_resp_hash = -1;
static int hf_wifi_dpp_key_x = -1;
static int hf_wifi_dpp_key_y = -1;
static int hf_wifi_dpp_trans_id = -1;
static int hf_wifi_dpp_finite_cyclic_group = -1;
static int hf_wifi_dpp_capabilities = -1;
static int hf_wifi_dpp_code_identifier = -1;
static int hf_wifi_dpp_enc_key_attribute = -1;
static int hf_wifi_dpp_primary_wrapped_data = -1;
static int hf_wifi_dpp_unknown_anqp_item = -1;

static int
dissect_wifi_dpp(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void *data _U_)
{
  int offset = 0;

  proto_tree_add_item(tree, hf_wifi_dpp_unknown_anqp_item, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_NA);
  return tvb_captured_length(tvb);
}

static int
dissect_wifi_dpp_ie(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void *data _U_)
{
  proto_item *ie;
  int offset = 0;
  gint remaining_len = tvb_reported_length(tvb);

  ie = proto_tree_add_subtree(tree, tvb, offset, remaining_len, ett_wifi_dpp_ie_generic, NULL, "Generic DPP IE");
  proto_tree_add_item(ie, hf_wifi_dpp_ie_generic, tvb, offset, remaining_len, ENC_NA);
  return tvb_captured_length(tvb);
}

int
dissect_wifi_dpp_attributes(packet_info *pinfo _U_, proto_tree *tree,
                            tvbuff_t *tvb, int offset _U_)
{
  proto_item *si = NULL;
  guint8 status;
  proto_tree *specific_attr, *attr_hdr;
  guint16 attribute_id;
  guint16 attribute_len;
  guint attributes_len = 0;
  guint remaining_len = tvb_reported_length_remaining(tvb, offset);

  while (remaining_len) {
    attribute_id = tvb_get_guint16(tvb, offset, ENC_LITTLE_ENDIAN);
    attribute_len = tvb_get_guint16(tvb, offset + 2, ENC_LITTLE_ENDIAN);
    specific_attr = proto_tree_add_subtree_format(tree, tvb, offset,
                                attribute_len + 4, ett_wifi_dpp_attribute,
                                &si, "%s Attribute",
                                val_to_str(attribute_id,
                                        dpp_ie_attr_ids,
                                        "Unknown (%u)"));
    attr_hdr = proto_tree_add_subtree_format(specific_attr, tvb, offset, 4,
                                        ett_wifi_dpp_attr_header, NULL,
                                        "Attribute Header");

    proto_tree_add_item(attr_hdr, hf_wifi_dpp_ie_attr_id, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;
    proto_tree_add_item(attr_hdr, hf_wifi_dpp_ie_attr_len, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;
    switch (attribute_id) {
    case DPP_STATUS:
      status = tvb_get_guint8(tvb, offset);
      proto_item_append_text(si, ": %s", val_to_str(status,
                                         dpp_status_codes,
                                         "Unknown (%u)"));
      proto_tree_add_item(specific_attr, hf_wifi_dpp_status, tvb, offset, attribute_len, ENC_LITTLE_ENDIAN);
      break;

    case DPP_INITIATOR_BOOTSTRAPPING_KEY_HASH:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_init_hash, tvb, offset, attribute_len, ENC_NA);
      break;

    case DPP_RESPONDER_BOOTSTRAPPING_KEY_HASH:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_resp_hash, tvb, offset, attribute_len, ENC_NA);
      break;

    case DPP_RESPONDER_PROTOCOL_KEY:
    case DPP_INITIATOR_PROTOCOL_KEY:
      // This is two protocol keys of equal length, X then Y.
      proto_tree_add_item(specific_attr, hf_wifi_dpp_key_x, tvb, offset, attribute_len/2, ENC_NA);
      proto_tree_add_item(specific_attr, hf_wifi_dpp_key_y, tvb, offset + attribute_len/2, attribute_len/2, ENC_NA);
      break;

    case DPP_TRANSACTION_ID:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_trans_id, tvb, offset, 1, ENC_LITTLE_ENDIAN);
      break;

    case DPP_FINITE_CYCLIC_GROUP:
    case DPP_RESPONDER_CAPABILITIES:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_finite_cyclic_group, tvb, offset, 2, ENC_LITTLE_ENDIAN);
      break;

    case DPP_INITIATOR_CAPABILITIES:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_capabilities, tvb, offset, 1, ENC_LITTLE_ENDIAN);
      break;

    case DPP_CODE_IDENTIFIER:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_code_identifier, tvb, offset, attribute_len, ENC_UTF_8|ENC_NA);
      break;

    case DPP_ENCRYPTED_KEY:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_enc_key_attribute, tvb, offset, attribute_len, ENC_NA);
      break;

    case DPP_WRAPPED_DATA:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_primary_wrapped_data, tvb, offset, attribute_len, ENC_NA);
      break;

    case DPP_INITIATOR_NONCE:

    case DPP_INITIATOR_AUTHENTICATING_TAG:

    case DPP_RESPONDER_AUTHENTICATING_TAG:

    case DPP_CONFIGURATION_OBJECT:

    case DPP_CONNECTOR:

    case DPP_CONFIGURATION_ATTRIBUTES_OBJECT:

    case DPP_BOOTSTRAPPING_KEY:

    case DPP_ENROLLEE_NONCE:

    default:
      proto_tree_add_item(specific_attr, hf_wifi_dpp_ie_generic, tvb, offset, attribute_len, ENC_NA);
      break;
    }

    offset += attribute_len;
    attributes_len += attribute_len + 4;
    remaining_len -= (attribute_len + 4);

  }

  return attributes_len; // We return the attribute length plus hdr!
}

static int
dissect_wifi_dpp_public_action(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
  guint8 subtype;
  guint remaining_len;
  proto_item *dpp_item;
  proto_tree *dpp_tree, *attr_tree;
  guint16 attributes_len;
  int offset = 0;

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "wifi_dpp");

  subtype = tvb_get_guint8(tvb, offset);
  col_append_fstr(pinfo->cinfo, COL_INFO, ", DPP - %s",
                  val_to_str(subtype, dpp_public_action_subtypes, "Unknown (%u)"));

  remaining_len = tvb_reported_length_remaining(tvb, offset);

  dpp_item = proto_tree_add_item(tree, proto_wifi_dpp, tvb, offset, -1, ENC_NA);
  dpp_tree = proto_item_add_subtree(dpp_item, ett_wifi_dpp_pa);
  proto_item_append_text(dpp_item, ": %s", val_to_str(subtype,
                                                      dpp_public_action_subtypes,
                                                      "Unknown (%u)"));
  proto_tree_add_item(dpp_tree, hf_wifi_dpp_public_action_subtype, tvb, offset, 1, ENC_LITTLE_ENDIAN);
  offset++;  /* Skip the OUI Subtype/DPP Request type */
  remaining_len--;
  if (remaining_len) {
    attr_tree = proto_tree_add_subtree_format(dpp_tree, tvb, offset,
                                              remaining_len,
                                              ett_wifi_dpp_attributes, NULL,
                                              "DPP Attributes");

    attributes_len = dissect_wifi_dpp_attributes(pinfo, attr_tree, tvb, offset);
    offset += attributes_len;
  }

  return offset;
}

static int
dissect_wifi_dpp_action(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, void *data _U_)
{
  int offset = 0;

  proto_tree_add_item(tree, hf_wifi_dpp_action_subtype, tvb, offset, 1, ENC_LITTLE_ENDIAN);
  offset++;
  proto_tree_add_item(tree, hf_wifi_dpp_action_dialog_token, tvb, offset, 1, ENC_LITTLE_ENDIAN);
  offset++;
  return offset;
}

void
proto_register_wifi_dpp(void)
{
  static hf_register_info hf[] = {
    { &hf_wifi_dpp_status,
      { "Wi-Fi DPP Status", "dpp.status",
        FT_UINT8, BASE_HEX, VALS(dpp_status_codes), 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_init_hash,
      { "Wi-Fi DPP Initiator Hash", "dpp.init.hash",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_resp_hash,
      { "Wi-Fi DPP Responder Hash", "dpp.resp.hash",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_key_x,
      { "Wi-Fi DPP Key X value", "dpp.key.x",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_key_y,
      { "Wi-Fi DPP Key Y value", "dpp.key.y",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_trans_id,
      { "Wi-Fi DPP Transaction ID", "dpp.trans_id",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_finite_cyclic_group,
      { "Wi-Fi DPP Finite Cyclic Group", "dpp.finite_cyclic_group",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_capabilities,
      { "Wi-Fi DPP Capabilities", "dpp.capabilities",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_code_identifier,
      { "Wi-Fi DPP Code Identifier", "dpp.code_identifier",
        FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_enc_key_attribute,
      { "Wi-Fi DPP Encrypted Key Attribute", "dpp.pkex.enckey",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_primary_wrapped_data,
      { "Wi-Fi DPP Primary Wrapped Data", "dpp.primary.wrapped_data",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_ie_attr_id,
      { "Wi-Fi DPP IE Attribute ID", "dpp.ie.attr_id",
        FT_UINT16, BASE_HEX, VALS(dpp_ie_attr_ids), 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_ie_attr_len,
      { "Wi-Fi DPP IE Attribute Len", "dpp.ie.attr_len",
       FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_ie_generic,
      { "Wi-Fi DPP IE generic", "dpp.ie.generic",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_action_subtype,
      { "Wi-Fi DPP Action Subtype", "dpp.action.subtype",
        FT_UINT8, BASE_DEC, VALS(dpp_action_subtypes), 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_action_dialog_token,
      { "Wi-Fi DPP Action Dialog Token", "dpp.action.dialog_token",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_public_action_subtype,
      { "Wi-Fi DPP Public Action Subtype", "dpp.public_action.subtype",
        FT_UINT8, BASE_DEC, VALS(dpp_public_action_subtypes), 0x0, NULL, HFILL }},
    { &hf_wifi_dpp_unknown_anqp_item,
      { "Wi-fi DPP Unknown ANQP Item", "dpp.unknown_anqp_item",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
  };
  static gint *ett[] = {
    &ett_wifi_dpp_ie_generic,
    &ett_wifi_dpp_attributes,
    &ett_wifi_dpp_pa,
    &ett_wifi_dpp_attribute,
    &ett_wifi_dpp_attr_header,
  };

  proto_wifi_dpp = proto_register_protocol("Wi-Fi Device Provisioning Protocol", "Wi-Fi DPP", "dpp");
  proto_register_field_array(proto_wifi_dpp, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));

}

void
proto_reg_handoff_wifi_dpp(void)
{
  dissector_add_uint("wlan.action.wifi_alliance.subtype", WFA_SUBTYPE_DPP, create_dissector_handle(dissect_wifi_dpp_action, proto_wifi_dpp));
  dissector_add_uint("wlan.anqp.wifi_alliance.subtype", WFA_SUBTYPE_DPP, create_dissector_handle(dissect_wifi_dpp, proto_wifi_dpp));
  dissector_add_uint("wlan.ie.wifi_alliance.subtype", WFA_SUBTYPE_DPP, create_dissector_handle(dissect_wifi_dpp_ie, proto_wifi_dpp));
  dissector_add_uint("wlan.pa.wifi_alliance.subtype", WFA_SUBTYPE_DPP, create_dissector_handle(dissect_wifi_dpp_public_action, proto_wifi_dpp));
}

/*
 * Editor modelines
 *
 * Local Variables:
 * c-basic-offset: 2
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set shiftwidth=2 tabstop=8 expandtab:
 * :indentSize=2:tabSize=8:noTabs=true:
 */