contrib/wpa/src/wps/wps_attr_build.c

   1 /*
   2  * Wi-Fi Protected Setup - attribute building
   3  * Copyright (c) 2008-2016, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "crypto/aes_wrap.h"
  13 #include "crypto/crypto.h"
  14 #include "crypto/dh_group5.h"
  15 #include "crypto/sha256.h"
  16 #include "crypto/random.h"
  17 #include "common/ieee802_11_defs.h"
  18 #include "wps_i.h"
  19
  20
  21 int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg)
  22 {
  23         struct wpabuf *pubkey = NULL;
  24
  25         wpa_printf(MSG_DEBUG, "WPS:  * Public Key");
  26         wpabuf_clear_free(wps->dh_privkey);
  27         wps->dh_privkey = NULL;
  28         if (wps->dev_pw_id != DEV_PW_DEFAULT && wps->wps->dh_privkey &&
  29             wps->wps->dh_ctx) {
  30                 wpa_printf(MSG_DEBUG, "WPS: Using pre-configured DH keys");
  31                 if (wps->wps->dh_pubkey == NULL) {
  32                         wpa_printf(MSG_DEBUG,
  33                                    "WPS: wps->wps->dh_pubkey == NULL");
  34                         return -1;
  35                 }
  36                 wps->dh_privkey = wpabuf_dup(wps->wps->dh_privkey);
  37                 wps->dh_ctx = wps->wps->dh_ctx;
  38                 wps->wps->dh_ctx = NULL;
  39                 pubkey = wpabuf_dup(wps->wps->dh_pubkey);
  40 #ifdef CONFIG_WPS_NFC
  41         } else if ((wps->dev_pw_id >= 0x10 ||
  42                     wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER) &&
  43                    (wps->wps->ap ||
  44                     (wps->wps->ap_nfc_dh_pubkey &&
  45                      wps->wps->ap_nfc_dev_pw_id ==
  46                      DEV_PW_NFC_CONNECTION_HANDOVER &&
  47                      wps->dev_pw_id == DEV_PW_NFC_CONNECTION_HANDOVER)) &&
  48                    (wps->dev_pw_id == wps->wps->ap_nfc_dev_pw_id ||
  49                     wps->wps->ap_nfc_dh_pubkey)) {
  50                 wpa_printf(MSG_DEBUG, "WPS: Using NFC password token DH keys");
  51                 if (wps->wps->ap_nfc_dh_privkey == NULL) {
  52                         wpa_printf(MSG_DEBUG,
  53                                    "WPS: wps->wps->ap_nfc_dh_privkey == NULL");
  54                         return -1;
  55                 }
  56                 if (wps->wps->ap_nfc_dh_pubkey == NULL) {
  57                         wpa_printf(MSG_DEBUG,
  58                                    "WPS: wps->wps->ap_nfc_dh_pubkey == NULL");
  59                         return -1;
  60                 }
  61                 wps->dh_privkey = wpabuf_dup(wps->wps->ap_nfc_dh_privkey);
  62                 pubkey = wpabuf_dup(wps->wps->ap_nfc_dh_pubkey);
  63                 if (wps->dh_privkey && pubkey)
  64                         wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey);
  65 #endif /* CONFIG_WPS_NFC */
  66         } else {
  67                 wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys");
  68                 dh5_free(wps->dh_ctx);
  69                 wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey);
  70                 pubkey = wpabuf_zeropad(pubkey, 192);
  71         }
  72         if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) {
  73                 wpa_printf(MSG_DEBUG, "WPS: Failed to initialize "
  74                            "Diffie-Hellman handshake");
  75                 wpabuf_free(pubkey);
  76                 return -1;
  77         }
  78         wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
  79         wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey);
  80
  81         wpabuf_put_be16(msg, ATTR_PUBLIC_KEY);
  82         wpabuf_put_be16(msg, wpabuf_len(pubkey));
  83         wpabuf_put_buf(msg, pubkey);
  84
  85         if (wps->registrar) {
  86                 wpabuf_free(wps->dh_pubkey_r);
  87                 wps->dh_pubkey_r = pubkey;
  88         } else {
  89                 wpabuf_free(wps->dh_pubkey_e);
  90                 wps->dh_pubkey_e = pubkey;
  91         }
  92
  93         return 0;
  94 }
  95
  96
  97 int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type)
  98 {
  99         wpa_printf(MSG_DEBUG, "WPS:  * Request Type");
 100         wpabuf_put_be16(msg, ATTR_REQUEST_TYPE);
 101         wpabuf_put_be16(msg, 1);
 102         wpabuf_put_u8(msg, type);
 103         return 0;
 104 }
 105
 106
 107 int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type)
 108 {
 109         wpa_printf(MSG_DEBUG, "WPS:  * Response Type (%d)", type);
 110         wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE);
 111         wpabuf_put_be16(msg, 1);
 112         wpabuf_put_u8(msg, type);
 113         return 0;
 114 }
 115
 116
 117 int wps_build_config_methods(struct wpabuf *msg, u16 methods)
 118 {
 119         wpa_printf(MSG_DEBUG, "WPS:  * Config Methods (%x)", methods);
 120         wpabuf_put_be16(msg, ATTR_CONFIG_METHODS);
 121         wpabuf_put_be16(msg, 2);
 122         wpabuf_put_be16(msg, methods);
 123         return 0;
 124 }
 125
 126
 127 int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid)
 128 {
 129         if (wpabuf_tailroom(msg) < 4 + WPS_UUID_LEN)
 130                 return -1;
 131         wpa_printf(MSG_DEBUG, "WPS:  * UUID-E");
 132         wpabuf_put_be16(msg, ATTR_UUID_E);
 133         wpabuf_put_be16(msg, WPS_UUID_LEN);
 134         wpabuf_put_data(msg, uuid, WPS_UUID_LEN);
 135         return 0;
 136 }
 137
 138
 139 int wps_build_dev_password_id(struct wpabuf *msg, u16 id)
 140 {
 141         wpa_printf(MSG_DEBUG, "WPS:  * Device Password ID (%d)", id);
 142         wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID);
 143         wpabuf_put_be16(msg, 2);
 144         wpabuf_put_be16(msg, id);
 145         return 0;
 146 }
 147
 148
 149 int wps_build_config_error(struct wpabuf *msg, u16 err)
 150 {
 151         wpa_printf(MSG_DEBUG, "WPS:  * Configuration Error (%d)", err);
 152         wpabuf_put_be16(msg, ATTR_CONFIG_ERROR);
 153         wpabuf_put_be16(msg, 2);
 154         wpabuf_put_be16(msg, err);
 155         return 0;
 156 }
 157
 158
 159 int wps_build_authenticator(struct wps_data *wps, struct wpabuf *msg)
 160 {
 161         u8 hash[SHA256_MAC_LEN];
 162         const u8 *addr[2];
 163         size_t len[2];
 164
 165         if (wps->last_msg == NULL) {
 166                 wpa_printf(MSG_DEBUG, "WPS: Last message not available for "
 167                            "building authenticator");
 168                 return -1;
 169         }
 170
 171         /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*)
 172          * (M_curr* is M_curr without the Authenticator attribute)
 173          */
 174         addr[0] = wpabuf_head(wps->last_msg);
 175         len[0] = wpabuf_len(wps->last_msg);
 176         addr[1] = wpabuf_head(msg);
 177         len[1] = wpabuf_len(msg);
 178         hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash);
 179
 180         wpa_printf(MSG_DEBUG, "WPS:  * Authenticator");
 181         wpabuf_put_be16(msg, ATTR_AUTHENTICATOR);
 182         wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN);
 183         wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN);
 184
 185         return 0;
 186 }
 187
 188
 189 int wps_build_version(struct wpabuf *msg)
 190 {
 191         /*
 192          * Note: This attribute is deprecated and set to hardcoded 0x10 for
 193          * backwards compatibility reasons. The real version negotiation is
 194          * done with Version2.
 195          */
 196         if (wpabuf_tailroom(msg) < 5)
 197                 return -1;
 198         wpa_printf(MSG_DEBUG, "WPS:  * Version (hardcoded 0x10)");
 199         wpabuf_put_be16(msg, ATTR_VERSION);
 200         wpabuf_put_be16(msg, 1);
 201         wpabuf_put_u8(msg, 0x10);
 202         return 0;
 203 }
 204
 205
 206 int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll,
 207                       const u8 *auth_macs, size_t auth_macs_count,
 208                       u8 multi_ap_subelem)
 209 {
 210         u8 *len;
 211
 212 #ifdef CONFIG_WPS_TESTING
 213         if (WPS_VERSION == 0x10)
 214                 return 0;
 215 #endif /* CONFIG_WPS_TESTING */
 216
 217         if (wpabuf_tailroom(msg) <
 218             7 + 3 + (req_to_enroll ? 3 : 0) +
 219             (auth_macs ? 2 + auth_macs_count * ETH_ALEN : 0))
 220                 return -1;
 221         wpabuf_put_be16(msg, ATTR_VENDOR_EXT);
 222         len = wpabuf_put(msg, 2); /* to be filled */
 223         wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA);
 224
 225         wpa_printf(MSG_DEBUG, "WPS:  * Version2 (0x%x)", WPS_VERSION);
 226         wpabuf_put_u8(msg, WFA_ELEM_VERSION2);
 227         wpabuf_put_u8(msg, 1);
 228         wpabuf_put_u8(msg, WPS_VERSION);
 229
 230         if (req_to_enroll) {
 231                 wpa_printf(MSG_DEBUG, "WPS:  * Request to Enroll (1)");
 232                 wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL);
 233                 wpabuf_put_u8(msg, 1);
 234                 wpabuf_put_u8(msg, 1);
 235         }
 236
 237         if (auth_macs && auth_macs_count) {
 238                 size_t i;
 239                 wpa_printf(MSG_DEBUG, "WPS:  * AuthorizedMACs (count=%d)",
 240                            (int) auth_macs_count);
 241                 wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS);
 242                 wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN);
 243                 wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN);
 244                 for (i = 0; i < auth_macs_count; i++)
 245                         wpa_printf(MSG_DEBUG, "WPS:    AuthorizedMAC: " MACSTR,
 246                                    MAC2STR(&auth_macs[i * ETH_ALEN]));
 247         }
 248
 249         if (multi_ap_subelem) {
 250                 wpa_printf(MSG_DEBUG, "WPS:  * Multi-AP (0x%x)",
 251                            multi_ap_subelem);
 252                 wpabuf_put_u8(msg, WFA_ELEM_MULTI_AP);
 253                 wpabuf_put_u8(msg, 1); /* length */
 254                 wpabuf_put_u8(msg, multi_ap_subelem);
 255         }
 256
 257         WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2);
 258
 259 #ifdef CONFIG_WPS_TESTING
 260         if (WPS_VERSION > 0x20) {
 261                 if (wpabuf_tailroom(msg) < 5)
 262                         return -1;
 263                 wpa_printf(MSG_DEBUG, "WPS:  * Extensibility Testing - extra "
 264                            "attribute");
 265                 wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST);
 266                 wpabuf_put_be16(msg, 1);
 267                 wpabuf_put_u8(msg, 42);
 268         }
 269 #endif /* CONFIG_WPS_TESTING */
 270         return 0;
 271 }
 272
 273
 274 int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type)
 275 {
 276         wpa_printf(MSG_DEBUG, "WPS:  * Message Type (%d)", msg_type);
 277         wpabuf_put_be16(msg, ATTR_MSG_TYPE);
 278         wpabuf_put_be16(msg, 1);
 279         wpabuf_put_u8(msg, msg_type);
 280         return 0;
 281 }
 282
 283
 284 int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg)
 285 {
 286         wpa_printf(MSG_DEBUG, "WPS:  * Enrollee Nonce");
 287         wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE);
 288         wpabuf_put_be16(msg, WPS_NONCE_LEN);
 289         wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN);
 290         return 0;
 291 }
 292
 293
 294 int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg)
 295 {
 296         wpa_printf(MSG_DEBUG, "WPS:  * Registrar Nonce");
 297         wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE);
 298         wpabuf_put_be16(msg, WPS_NONCE_LEN);
 299         wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN);
 300         return 0;
 301 }
 302
 303
 304 int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg)
 305 {
 306         u16 auth_types = WPS_AUTH_TYPES;
 307         /* WPA/WPA2-Enterprise enrollment not supported through WPS */
 308         auth_types &= ~WPS_AUTH_WPA;
 309         auth_types &= ~WPS_AUTH_WPA2;
 310         auth_types &= ~WPS_AUTH_SHARED;
 311 #ifdef CONFIG_WPS_TESTING
 312         if (wps_force_auth_types_in_use) {
 313                 wpa_printf(MSG_DEBUG,
 314                            "WPS: Testing - replace auth type 0x%x with 0x%x",
 315                            auth_types, wps_force_auth_types);
 316                 auth_types = wps_force_auth_types;
 317         }
 318 #endif /* CONFIG_WPS_TESTING */
 319         wpa_printf(MSG_DEBUG, "WPS:  * Authentication Type Flags (0x%x)",
 320                    auth_types);
 321         wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS);
 322         wpabuf_put_be16(msg, 2);
 323         wpabuf_put_be16(msg, auth_types);
 324         return 0;
 325 }
 326
 327
 328 int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg)
 329 {
 330         u16 encr_types = WPS_ENCR_TYPES;
 331         encr_types &= ~WPS_ENCR_WEP;
 332 #ifdef CONFIG_WPS_TESTING
 333         if (wps_force_encr_types_in_use) {
 334                 wpa_printf(MSG_DEBUG,
 335                            "WPS: Testing - replace encr type 0x%x with 0x%x",
 336                            encr_types, wps_force_encr_types);
 337                 encr_types = wps_force_encr_types;
 338         }
 339 #endif /* CONFIG_WPS_TESTING */
 340         wpa_printf(MSG_DEBUG, "WPS:  * Encryption Type Flags (0x%x)",
 341                    encr_types);
 342         wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS);
 343         wpabuf_put_be16(msg, 2);
 344         wpabuf_put_be16(msg, encr_types);
 345         return 0;
 346 }
 347
 348
 349 int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg)
 350 {
 351         wpa_printf(MSG_DEBUG, "WPS:  * Connection Type Flags");
 352         wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS);
 353         wpabuf_put_be16(msg, 1);
 354         wpabuf_put_u8(msg, WPS_CONN_ESS);
 355         return 0;
 356 }
 357
 358
 359 int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg)
 360 {
 361         wpa_printf(MSG_DEBUG, "WPS:  * Association State");
 362         wpabuf_put_be16(msg, ATTR_ASSOC_STATE);
 363         wpabuf_put_be16(msg, 2);
 364         wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC);
 365         return 0;
 366 }
 367
 368
 369 int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg)
 370 {
 371         u8 hash[SHA256_MAC_LEN];
 372
 373         wpa_printf(MSG_DEBUG, "WPS:  * Key Wrap Authenticator");
 374         hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg),
 375                     wpabuf_len(msg), hash);
 376
 377         wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH);
 378         wpabuf_put_be16(msg, WPS_KWA_LEN);
 379         wpabuf_put_data(msg, hash, WPS_KWA_LEN);
 380         return 0;
 381 }
 382
 383
 384 int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg,
 385                             struct wpabuf *plain)
 386 {
 387         size_t pad_len;
 388         const size_t block_size = 16;
 389         u8 *iv, *data;
 390
 391         wpa_printf(MSG_DEBUG, "WPS:  * Encrypted Settings");
 392
 393         /* PKCS#5 v2.0 pad */
 394         pad_len = block_size - wpabuf_len(plain) % block_size;
 395         os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len);
 396
 397         wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS);
 398         wpabuf_put_be16(msg, block_size + wpabuf_len(plain));
 399
 400         iv = wpabuf_put(msg, block_size);
 401         if (random_get_bytes(iv, block_size) < 0)
 402                 return -1;
 403
 404         data = wpabuf_put(msg, 0);
 405         wpabuf_put_buf(msg, plain);
 406         if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain)))
 407                 return -1;
 408
 409         return 0;
 410 }
 411
 412
 413 #ifdef CONFIG_WPS_OOB
 414 int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id,
 415                          const struct wpabuf *pubkey, const u8 *dev_pw,
 416                          size_t dev_pw_len)
 417 {
 418         size_t hash_len;
 419         const u8 *addr[1];
 420         u8 pubkey_hash[WPS_HASH_LEN];
 421
 422         wpa_printf(MSG_DEBUG, "WPS:  * OOB Device Password (dev_pw_id=%u)",
 423                    dev_pw_id);
 424         addr[0] = wpabuf_head(pubkey);
 425         hash_len = wpabuf_len(pubkey);
 426         if (sha256_vector(1, addr, &hash_len, pubkey_hash) < 0)
 427                 return -1;
 428 #ifdef CONFIG_WPS_TESTING
 429         if (wps_corrupt_pkhash) {
 430                 wpa_hexdump(MSG_DEBUG, "WPS: Real Public Key Hash",
 431                             pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
 432                 wpa_printf(MSG_INFO, "WPS: Testing - corrupt public key hash");
 433                 pubkey_hash[WPS_OOB_PUBKEY_HASH_LEN - 2]++;
 434         }
 435 #endif /* CONFIG_WPS_TESTING */
 436
 437         wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD);
 438         wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len);
 439         wpa_hexdump(MSG_DEBUG, "WPS: Public Key Hash",
 440                     pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
 441         wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN);
 442         wpabuf_put_be16(msg, dev_pw_id);
 443         if (dev_pw) {
 444                 wpa_hexdump_key(MSG_DEBUG, "WPS: OOB Device Password",
 445                                 dev_pw, dev_pw_len);
 446                 wpabuf_put_data(msg, dev_pw, dev_pw_len);
 447         }
 448
 449         return 0;
 450 }
 451 #endif /* CONFIG_WPS_OOB */
 452
 453
 454 /* Encapsulate WPS IE data with one (or more, if needed) IE headers */
 455 struct wpabuf * wps_ie_encapsulate(struct wpabuf *data)
 456 {
 457         struct wpabuf *ie;
 458         const u8 *pos, *end;
 459
 460         ie = wpabuf_alloc(wpabuf_len(data) + 100);
 461         if (ie == NULL) {
 462                 wpabuf_free(data);
 463                 return NULL;
 464         }
 465
 466         pos = wpabuf_head(data);
 467         end = pos + wpabuf_len(data);
 468
 469         while (end > pos) {
 470                 size_t frag_len = end - pos;
 471                 if (frag_len > 251)
 472                         frag_len = 251;
 473                 wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC);
 474                 wpabuf_put_u8(ie, 4 + frag_len);
 475                 wpabuf_put_be32(ie, WPS_DEV_OUI_WFA);
 476                 wpabuf_put_data(ie, pos, frag_len);
 477                 pos += frag_len;
 478         }
 479
 480         wpabuf_free(data);
 481
 482         return ie;
 483 }
 484
 485
 486 int wps_build_mac_addr(struct wpabuf *msg, const u8 *addr)
 487 {
 488         wpa_printf(MSG_DEBUG, "WPS:  * MAC Address (" MACSTR ")",
 489                    MAC2STR(addr));
 490         wpabuf_put_be16(msg, ATTR_MAC_ADDR);
 491         wpabuf_put_be16(msg, ETH_ALEN);
 492         wpabuf_put_data(msg, addr, ETH_ALEN);
 493         return 0;
 494 }
 495
 496
 497 int wps_build_rf_bands_attr(struct wpabuf *msg, u8 rf_bands)
 498 {
 499         wpa_printf(MSG_DEBUG, "WPS:  * RF Bands (%x)", rf_bands);
 500         wpabuf_put_be16(msg, ATTR_RF_BANDS);
 501         wpabuf_put_be16(msg, 1);
 502         wpabuf_put_u8(msg, rf_bands);
 503         return 0;
 504 }
 505
 506
 507 int wps_build_ap_channel(struct wpabuf *msg, u16 ap_channel)
 508 {
 509         wpa_printf(MSG_DEBUG, "WPS:  * AP Channel (%u)", ap_channel);
 510         wpabuf_put_be16(msg, ATTR_AP_CHANNEL);
 511         wpabuf_put_be16(msg, 2);
 512         wpabuf_put_be16(msg, ap_channel);
 513         return 0;
 514 }