src/wps/wps_common.c

   1 /*
   2  * Wi-Fi Protected Setup - common functionality
   3  * Copyright (c) 2008-2012, 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 "common/defs.h"
  13 #include "common/ieee802_11_common.h"
  14 #include "crypto/aes_wrap.h"
  15 #include "crypto/crypto.h"
  16 #include "crypto/dh_group5.h"
  17 #include "crypto/sha1.h"
  18 #include "crypto/sha256.h"
  19 #include "crypto/random.h"
  20 #include "wps_i.h"
  21 #include "wps_dev_attr.h"
  22
  23
  24 void wps_kdf(const u8 *key, const u8 *label_prefix, size_t label_prefix_len,
  25              const char *label, u8 *res, size_t res_len)
  26 {
  27         u8 i_buf[4], key_bits[4];
  28         const u8 *addr[4];
  29         size_t len[4];
  30         int i, iter;
  31         u8 hash[SHA256_MAC_LEN], *opos;
  32         size_t left;
  33
  34         WPA_PUT_BE32(key_bits, res_len * 8);
  35
  36         addr[0] = i_buf;
  37         len[0] = sizeof(i_buf);
  38         addr[1] = label_prefix;
  39         len[1] = label_prefix_len;
  40         addr[2] = (const u8 *) label;
  41         len[2] = os_strlen(label);
  42         addr[3] = key_bits;
  43         len[3] = sizeof(key_bits);
  44
  45         iter = (res_len + SHA256_MAC_LEN - 1) / SHA256_MAC_LEN;
  46         opos = res;
  47         left = res_len;
  48
  49         for (i = 1; i <= iter; i++) {
  50                 WPA_PUT_BE32(i_buf, i);
  51                 hmac_sha256_vector(key, SHA256_MAC_LEN, 4, addr, len, hash);
  52                 if (i < iter) {
  53                         os_memcpy(opos, hash, SHA256_MAC_LEN);
  54                         opos += SHA256_MAC_LEN;
  55                         left -= SHA256_MAC_LEN;
  56                 } else
  57                         os_memcpy(opos, hash, left);
  58         }
  59 }
  60
  61
  62 int wps_derive_keys(struct wps_data *wps)
  63 {
  64         struct wpabuf *pubkey, *dh_shared;
  65         u8 dhkey[SHA256_MAC_LEN], kdk[SHA256_MAC_LEN];
  66         const u8 *addr[3];
  67         size_t len[3];
  68         u8 keys[WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN + WPS_EMSK_LEN];
  69
  70         if (wps->dh_privkey == NULL) {
  71                 wpa_printf(MSG_DEBUG, "WPS: Own DH private key not available");
  72                 return -1;
  73         }
  74
  75         pubkey = wps->registrar ? wps->dh_pubkey_e : wps->dh_pubkey_r;
  76         if (pubkey == NULL) {
  77                 wpa_printf(MSG_DEBUG, "WPS: Peer DH public key not available");
  78                 return -1;
  79         }
  80
  81         wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
  82         wpa_hexdump_buf(MSG_DEBUG, "WPS: DH peer Public Key", pubkey);
  83         dh_shared = dh5_derive_shared(wps->dh_ctx, pubkey, wps->dh_privkey);
  84         dh5_free(wps->dh_ctx);
  85         wps->dh_ctx = NULL;
  86         dh_shared = wpabuf_zeropad(dh_shared, 192);
  87         if (dh_shared == NULL) {
  88                 wpa_printf(MSG_DEBUG, "WPS: Failed to derive DH shared key");
  89                 return -1;
  90         }
  91
  92         /* Own DH private key is not needed anymore */
  93         wpabuf_free(wps->dh_privkey);
  94         wps->dh_privkey = NULL;
  95
  96         wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH shared key", dh_shared);
  97
  98         /* DHKey = SHA-256(g^AB mod p) */
  99         addr[0] = wpabuf_head(dh_shared);
 100         len[0] = wpabuf_len(dh_shared);
 101         sha256_vector(1, addr, len, dhkey);
 102         wpa_hexdump_key(MSG_DEBUG, "WPS: DHKey", dhkey, sizeof(dhkey));
 103         wpabuf_free(dh_shared);
 104
 105         /* KDK = HMAC-SHA-256_DHKey(N1 || EnrolleeMAC || N2) */
 106         addr[0] = wps->nonce_e;
 107         len[0] = WPS_NONCE_LEN;
 108         addr[1] = wps->mac_addr_e;
 109         len[1] = ETH_ALEN;
 110         addr[2] = wps->nonce_r;
 111         len[2] = WPS_NONCE_LEN;
 112         hmac_sha256_vector(dhkey, sizeof(dhkey), 3, addr, len, kdk);
 113         wpa_hexdump_key(MSG_DEBUG, "WPS: KDK", kdk, sizeof(kdk));
 114
 115         wps_kdf(kdk, NULL, 0, "Wi-Fi Easy and Secure Key Derivation",
 116                 keys, sizeof(keys));
 117         os_memcpy(wps->authkey, keys, WPS_AUTHKEY_LEN);
 118         os_memcpy(wps->keywrapkey, keys + WPS_AUTHKEY_LEN, WPS_KEYWRAPKEY_LEN);
 119         os_memcpy(wps->emsk, keys + WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN,
 120                   WPS_EMSK_LEN);
 121
 122         wpa_hexdump_key(MSG_DEBUG, "WPS: AuthKey",
 123                         wps->authkey, WPS_AUTHKEY_LEN);
 124         wpa_hexdump_key(MSG_DEBUG, "WPS: KeyWrapKey",
 125                         wps->keywrapkey, WPS_KEYWRAPKEY_LEN);
 126         wpa_hexdump_key(MSG_DEBUG, "WPS: EMSK", wps->emsk, WPS_EMSK_LEN);
 127
 128         return 0;
 129 }
 130
 131
 132 void wps_derive_psk(struct wps_data *wps, const u8 *dev_passwd,
 133                     size_t dev_passwd_len)
 134 {
 135         u8 hash[SHA256_MAC_LEN];
 136
 137         hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd,
 138                     (dev_passwd_len + 1) / 2, hash);
 139         os_memcpy(wps->psk1, hash, WPS_PSK_LEN);
 140         hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN,
 141                     dev_passwd + (dev_passwd_len + 1) / 2,
 142                     dev_passwd_len / 2, hash);
 143         os_memcpy(wps->psk2, hash, WPS_PSK_LEN);
 144
 145         wpa_hexdump_ascii_key(MSG_DEBUG, "WPS: Device Password",
 146                               dev_passwd, dev_passwd_len);
 147         wpa_hexdump_key(MSG_DEBUG, "WPS: PSK1", wps->psk1, WPS_PSK_LEN);
 148         wpa_hexdump_key(MSG_DEBUG, "WPS: PSK2", wps->psk2, WPS_PSK_LEN);
 149 }
 150
 151
 152 struct wpabuf * wps_decrypt_encr_settings(struct wps_data *wps, const u8 *encr,
 153                                           size_t encr_len)
 154 {
 155         struct wpabuf *decrypted;
 156         const size_t block_size = 16;
 157         size_t i;
 158         u8 pad;
 159         const u8 *pos;
 160
 161         /* AES-128-CBC */
 162         if (encr == NULL || encr_len < 2 * block_size || encr_len % block_size)
 163         {
 164                 wpa_printf(MSG_DEBUG, "WPS: No Encrypted Settings received");
 165                 return NULL;
 166         }
 167
 168         decrypted = wpabuf_alloc(encr_len - block_size);
 169         if (decrypted == NULL)
 170                 return NULL;
 171
 172         wpa_hexdump(MSG_MSGDUMP, "WPS: Encrypted Settings", encr, encr_len);
 173         wpabuf_put_data(decrypted, encr + block_size, encr_len - block_size);
 174         if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted),
 175                                 wpabuf_len(decrypted))) {
 176                 wpabuf_free(decrypted);
 177                 return NULL;
 178         }
 179
 180         wpa_hexdump_buf_key(MSG_MSGDUMP, "WPS: Decrypted Encrypted Settings",
 181                             decrypted);
 182
 183         pos = wpabuf_head_u8(decrypted) + wpabuf_len(decrypted) - 1;
 184         pad = *pos;
 185         if (pad > wpabuf_len(decrypted)) {
 186                 wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad value");
 187                 wpabuf_free(decrypted);
 188                 return NULL;
 189         }
 190         for (i = 0; i < pad; i++) {
 191                 if (*pos-- != pad) {
 192                         wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad "
 193                                    "string");
 194                         wpabuf_free(decrypted);
 195                         return NULL;
 196                 }
 197         }
 198         decrypted->used -= pad;
 199
 200         return decrypted;
 201 }
 202
 203
 204 /**
 205  * wps_pin_checksum - Compute PIN checksum
 206  * @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
 207  * Returns: Checksum digit
 208  */
 209 unsigned int wps_pin_checksum(unsigned int pin)
 210 {
 211         unsigned int accum = 0;
 212         while (pin) {
 213                 accum += 3 * (pin % 10);
 214                 pin /= 10;
 215                 accum += pin % 10;
 216                 pin /= 10;
 217         }
 218
 219         return (10 - accum % 10) % 10;
 220 }
 221
 222
 223 /**
 224  * wps_pin_valid - Check whether a PIN has a valid checksum
 225  * @pin: Eight digit PIN (i.e., including the checksum digit)
 226  * Returns: 1 if checksum digit is valid, or 0 if not
 227  */
 228 unsigned int wps_pin_valid(unsigned int pin)
 229 {
 230         return wps_pin_checksum(pin / 10) == (pin % 10);
 231 }
 232
 233
 234 /**
 235  * wps_generate_pin - Generate a random PIN
 236  * Returns: Eight digit PIN (i.e., including the checksum digit)
 237  */
 238 unsigned int wps_generate_pin(void)
 239 {
 240         unsigned int val;
 241
 242         /* Generate seven random digits for the PIN */
 243         if (random_get_bytes((unsigned char *) &val, sizeof(val)) < 0) {
 244                 struct os_time now;
 245                 os_get_time(&now);
 246                 val = os_random() ^ now.sec ^ now.usec;
 247         }
 248         val %= 10000000;
 249
 250         /* Append checksum digit */
 251         return val * 10 + wps_pin_checksum(val);
 252 }
 253
 254
 255 int wps_pin_str_valid(const char *pin)
 256 {
 257         const char *p;
 258         size_t len;
 259
 260         p = pin;
 261         while (*p >= '0' && *p <= '9')
 262                 p++;
 263         if (*p != '\0')
 264                 return 0;
 265
 266         len = p - pin;
 267         return len == 4 || len == 8;
 268 }
 269
 270
 271 void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg,
 272                     u16 config_error, u16 error_indication, const u8 *mac_addr)
 273 {
 274         union wps_event_data data;
 275
 276         if (wps->event_cb == NULL)
 277                 return;
 278
 279         os_memset(&data, 0, sizeof(data));
 280         data.fail.msg = msg;
 281         data.fail.config_error = config_error;
 282         data.fail.error_indication = error_indication;
 283         os_memcpy(data.fail.peer_macaddr, mac_addr, ETH_ALEN);
 284         wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, &data);
 285 }
 286
 287
 288 void wps_success_event(struct wps_context *wps, const u8 *mac_addr)
 289 {
 290         union wps_event_data data;
 291
 292         if (wps->event_cb == NULL)
 293                 return;
 294
 295         os_memset(&data, 0, sizeof(data));
 296         os_memcpy(data.success.peer_macaddr, mac_addr, ETH_ALEN);
 297         wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, &data);
 298 }
 299
 300
 301 void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part,
 302                              const u8 *mac_addr)
 303 {
 304         union wps_event_data data;
 305
 306         if (wps->event_cb == NULL)
 307                 return;
 308
 309         os_memset(&data, 0, sizeof(data));
 310         data.pwd_auth_fail.enrollee = enrollee;
 311         data.pwd_auth_fail.part = part;
 312         os_memcpy(data.pwd_auth_fail.peer_macaddr, mac_addr, ETH_ALEN);
 313         wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, &data);
 314 }
 315
 316
 317 void wps_pbc_overlap_event(struct wps_context *wps)
 318 {
 319         if (wps->event_cb == NULL)
 320                 return;
 321
 322         wps->event_cb(wps->cb_ctx, WPS_EV_PBC_OVERLAP, NULL);
 323 }
 324
 325
 326 void wps_pbc_timeout_event(struct wps_context *wps)
 327 {
 328         if (wps->event_cb == NULL)
 329                 return;
 330
 331         wps->event_cb(wps->cb_ctx, WPS_EV_PBC_TIMEOUT, NULL);
 332 }
 333
 334
 335 void wps_pbc_active_event(struct wps_context *wps)
 336 {
 337         if (wps->event_cb == NULL)
 338                 return;
 339
 340         wps->event_cb(wps->cb_ctx, WPS_EV_PBC_ACTIVE, NULL);
 341 }
 342
 343
 344 void wps_pbc_disable_event(struct wps_context *wps)
 345 {
 346         if (wps->event_cb == NULL)
 347                 return;
 348
 349         wps->event_cb(wps->cb_ctx, WPS_EV_PBC_DISABLE, NULL);
 350 }
 351
 352
 353 #ifdef CONFIG_WPS_OOB
 354
 355 struct wpabuf * wps_get_oob_cred(struct wps_context *wps)
 356 {
 357         struct wps_data data;
 358         struct wpabuf *plain;
 359
 360         plain = wpabuf_alloc(500);
 361         if (plain == NULL) {
 362                 wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB "
 363                            "credential");
 364                 return NULL;
 365         }
 366
 367         os_memset(&data, 0, sizeof(data));
 368         data.wps = wps;
 369         data.auth_type = wps->auth_types;
 370         data.encr_type = wps->encr_types;
 371         if (wps_build_cred(&data, plain) ||
 372             wps_build_wfa_ext(plain, 0, NULL, 0)) {
 373                 os_free(data.new_psk);
 374                 wpabuf_free(plain);
 375                 return NULL;
 376         }
 377
 378         if (wps->wps_state == WPS_STATE_NOT_CONFIGURED && data.new_psk &&
 379             wps->ap) {
 380                 struct wps_credential cred;
 381
 382                 wpa_printf(MSG_DEBUG, "WPS: Moving to Configured state based "
 383                            "on credential token generation");
 384
 385                 os_memset(&cred, 0, sizeof(cred));
 386                 os_memcpy(cred.ssid, wps->ssid, wps->ssid_len);
 387                 cred.ssid_len = wps->ssid_len;
 388                 cred.auth_type = WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK;
 389                 cred.encr_type = WPS_ENCR_TKIP | WPS_ENCR_AES;
 390                 os_memcpy(cred.key, data.new_psk, data.new_psk_len);
 391                 cred.key_len = data.new_psk_len;
 392
 393                 wps->wps_state = WPS_STATE_CONFIGURED;
 394                 wpa_hexdump_ascii_key(MSG_DEBUG,
 395                                       "WPS: Generated random passphrase",
 396                                       data.new_psk, data.new_psk_len);
 397                 if (wps->cred_cb)
 398                         wps->cred_cb(wps->cb_ctx, &cred);
 399         }
 400
 401         os_free(data.new_psk);
 402
 403         return plain;
 404 }
 405
 406
 407 struct wpabuf * wps_build_nfc_pw_token(u16 dev_pw_id,
 408                                        const struct wpabuf *pubkey,
 409                                        const struct wpabuf *dev_pw)
 410 {
 411         struct wpabuf *data;
 412
 413         data = wpabuf_alloc(200);
 414         if (data == NULL)
 415                 return NULL;
 416
 417         if (wps_build_oob_dev_pw(data, dev_pw_id, pubkey,
 418                                  wpabuf_head(dev_pw), wpabuf_len(dev_pw)) ||
 419             wps_build_wfa_ext(data, 0, NULL, 0)) {
 420                 wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password "
 421                            "token");
 422                 wpabuf_free(data);
 423                 return NULL;
 424         }
 425
 426         return data;
 427 }
 428
 429
 430 int wps_oob_use_cred(struct wps_context *wps, struct wps_parse_attr *attr)
 431 {
 432         struct wpabuf msg;
 433         size_t i;
 434
 435         for (i = 0; i < attr->num_cred; i++) {
 436                 struct wps_credential local_cred;
 437                 struct wps_parse_attr cattr;
 438
 439                 os_memset(&local_cred, 0, sizeof(local_cred));
 440                 wpabuf_set(&msg, attr->cred[i], attr->cred_len[i]);
 441                 if (wps_parse_msg(&msg, &cattr) < 0 ||
 442                     wps_process_cred(&cattr, &local_cred)) {
 443                         wpa_printf(MSG_ERROR, "WPS: Failed to parse OOB "
 444                                    "credential");
 445                         return -1;
 446                 }
 447                 wps->cred_cb(wps->cb_ctx, &local_cred);
 448         }
 449
 450         return 0;
 451 }
 452
 453
 454 #endif /* CONFIG_WPS_OOB */
 455
 456
 457 int wps_dev_type_str2bin(const char *str, u8 dev_type[WPS_DEV_TYPE_LEN])
 458 {
 459         const char *pos;
 460
 461         /* <categ>-<OUI>-<subcateg> */
 462         WPA_PUT_BE16(dev_type, atoi(str));
 463         pos = os_strchr(str, '-');
 464         if (pos == NULL)
 465                 return -1;
 466         pos++;
 467         if (hexstr2bin(pos, &dev_type[2], 4))
 468                 return -1;
 469         pos = os_strchr(pos, '-');
 470         if (pos == NULL)
 471                 return -1;
 472         pos++;
 473         WPA_PUT_BE16(&dev_type[6], atoi(pos));
 474
 475
 476         return 0;
 477 }
 478
 479
 480 char * wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN], char *buf,
 481                             size_t buf_len)
 482 {
 483         int ret;
 484
 485         ret = os_snprintf(buf, buf_len, "%u-%08X-%u",
 486                           WPA_GET_BE16(dev_type), WPA_GET_BE32(&dev_type[2]),
 487                           WPA_GET_BE16(&dev_type[6]));
 488         if (ret < 0 || (unsigned int) ret >= buf_len)
 489                 return NULL;
 490
 491         return buf;
 492 }
 493
 494
 495 void uuid_gen_mac_addr(const u8 *mac_addr, u8 *uuid)
 496 {
 497         const u8 *addr[2];
 498         size_t len[2];
 499         u8 hash[SHA1_MAC_LEN];
 500         u8 nsid[16] = {
 501                 0x52, 0x64, 0x80, 0xf8,
 502                 0xc9, 0x9b,
 503                 0x4b, 0xe5,
 504                 0xa6, 0x55,
 505                 0x58, 0xed, 0x5f, 0x5d, 0x60, 0x84
 506         };
 507
 508         addr[0] = nsid;
 509         len[0] = sizeof(nsid);
 510         addr[1] = mac_addr;
 511         len[1] = 6;
 512         sha1_vector(2, addr, len, hash);
 513         os_memcpy(uuid, hash, 16);
 514
 515         /* Version: 5 = named-based version using SHA-1 */
 516         uuid[6] = (5 << 4) | (uuid[6] & 0x0f);
 517
 518         /* Variant specified in RFC 4122 */
 519         uuid[8] = 0x80 | (uuid[8] & 0x3f);
 520 }
 521
 522
 523 u16 wps_config_methods_str2bin(const char *str)
 524 {
 525         u16 methods = 0;
 526
 527         if (str == NULL) {
 528                 /* Default to enabling methods based on build configuration */
 529                 methods |= WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD;
 530 #ifdef CONFIG_WPS2
 531                 methods |= WPS_CONFIG_VIRT_DISPLAY;
 532 #endif /* CONFIG_WPS2 */
 533 #ifdef CONFIG_WPS_NFC
 534                 methods |= WPS_CONFIG_NFC_INTERFACE;
 535 #endif /* CONFIG_WPS_NFC */
 536         } else {
 537                 if (os_strstr(str, "ethernet"))
 538                         methods |= WPS_CONFIG_ETHERNET;
 539                 if (os_strstr(str, "label"))
 540                         methods |= WPS_CONFIG_LABEL;
 541                 if (os_strstr(str, "display"))
 542                         methods |= WPS_CONFIG_DISPLAY;
 543                 if (os_strstr(str, "ext_nfc_token"))
 544                         methods |= WPS_CONFIG_EXT_NFC_TOKEN;
 545                 if (os_strstr(str, "int_nfc_token"))
 546                         methods |= WPS_CONFIG_INT_NFC_TOKEN;
 547                 if (os_strstr(str, "nfc_interface"))
 548                         methods |= WPS_CONFIG_NFC_INTERFACE;
 549                 if (os_strstr(str, "push_button"))
 550                         methods |= WPS_CONFIG_PUSHBUTTON;
 551                 if (os_strstr(str, "keypad"))
 552                         methods |= WPS_CONFIG_KEYPAD;
 553 #ifdef CONFIG_WPS2
 554                 if (os_strstr(str, "virtual_display"))
 555                         methods |= WPS_CONFIG_VIRT_DISPLAY;
 556                 if (os_strstr(str, "physical_display"))
 557                         methods |= WPS_CONFIG_PHY_DISPLAY;
 558                 if (os_strstr(str, "virtual_push_button"))
 559                         methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
 560                 if (os_strstr(str, "physical_push_button"))
 561                         methods |= WPS_CONFIG_PHY_PUSHBUTTON;
 562 #endif /* CONFIG_WPS2 */
 563         }
 564
 565         return methods;
 566 }
 567
 568
 569 struct wpabuf * wps_build_wsc_ack(struct wps_data *wps)
 570 {
 571         struct wpabuf *msg;
 572
 573         wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_ACK");
 574
 575         msg = wpabuf_alloc(1000);
 576         if (msg == NULL)
 577                 return NULL;
 578
 579         if (wps_build_version(msg) ||
 580             wps_build_msg_type(msg, WPS_WSC_ACK) ||
 581             wps_build_enrollee_nonce(wps, msg) ||
 582             wps_build_registrar_nonce(wps, msg) ||
 583             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 584                 wpabuf_free(msg);
 585                 return NULL;
 586         }
 587
 588         return msg;
 589 }
 590
 591
 592 struct wpabuf * wps_build_wsc_nack(struct wps_data *wps)
 593 {
 594         struct wpabuf *msg;
 595
 596         wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_NACK");
 597
 598         msg = wpabuf_alloc(1000);
 599         if (msg == NULL)
 600                 return NULL;
 601
 602         if (wps_build_version(msg) ||
 603             wps_build_msg_type(msg, WPS_WSC_NACK) ||
 604             wps_build_enrollee_nonce(wps, msg) ||
 605             wps_build_registrar_nonce(wps, msg) ||
 606             wps_build_config_error(msg, wps->config_error) ||
 607             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 608                 wpabuf_free(msg);
 609                 return NULL;
 610         }
 611
 612         return msg;
 613 }
 614
 615
 616 #ifdef CONFIG_WPS_NFC
 617
 618 struct wpabuf * wps_nfc_token_build(int ndef, int id, struct wpabuf *pubkey,
 619                                     struct wpabuf *dev_pw)
 620 {
 621         struct wpabuf *ret;
 622
 623         if (pubkey == NULL || dev_pw == NULL)
 624                 return NULL;
 625
 626         ret = wps_build_nfc_pw_token(id, pubkey, dev_pw);
 627         if (ndef && ret) {
 628                 struct wpabuf *tmp;
 629                 tmp = ndef_build_wifi(ret);
 630                 wpabuf_free(ret);
 631                 if (tmp == NULL)
 632                         return NULL;
 633                 ret = tmp;
 634         }
 635
 636         return ret;
 637 }
 638
 639
 640 int wps_nfc_gen_dh(struct wpabuf **pubkey, struct wpabuf **privkey)
 641 {
 642         struct wpabuf *priv = NULL, *pub = NULL;
 643         void *dh_ctx;
 644
 645         dh_ctx = dh5_init(&priv, &pub);
 646         if (dh_ctx == NULL)
 647                 return -1;
 648         pub = wpabuf_zeropad(pub, 192);
 649         if (pub == NULL) {
 650                 wpabuf_free(priv);
 651                 return -1;
 652         }
 653         wpa_hexdump_buf(MSG_DEBUG, "WPS: Generated new DH pubkey", pub);
 654         dh5_free(dh_ctx);
 655
 656         wpabuf_free(*pubkey);
 657         *pubkey = pub;
 658         wpabuf_free(*privkey);
 659         *privkey = priv;
 660
 661         return 0;
 662 }
 663
 664
 665 struct wpabuf * wps_nfc_token_gen(int ndef, int *id, struct wpabuf **pubkey,
 666                                   struct wpabuf **privkey,
 667                                   struct wpabuf **dev_pw)
 668 {
 669         struct wpabuf *pw;
 670         u16 val;
 671
 672         pw = wpabuf_alloc(WPS_OOB_DEVICE_PASSWORD_LEN);
 673         if (pw == NULL)
 674                 return NULL;
 675
 676         if (random_get_bytes(wpabuf_put(pw, WPS_OOB_DEVICE_PASSWORD_LEN),
 677                              WPS_OOB_DEVICE_PASSWORD_LEN) ||
 678             random_get_bytes((u8 *) &val, sizeof(val))) {
 679                 wpabuf_free(pw);
 680                 return NULL;
 681         }
 682
 683         if (wps_nfc_gen_dh(pubkey, privkey) < 0) {
 684                 wpabuf_free(pw);
 685                 return NULL;
 686         }
 687
 688         *id = 0x10 + val % 0xfff0;
 689         wpabuf_free(*dev_pw);
 690         *dev_pw = pw;
 691
 692         return wps_nfc_token_build(ndef, *id, *pubkey, *dev_pw);
 693 }
 694
 695
 696 struct wpabuf * wps_build_nfc_handover_req(struct wps_context *ctx,
 697                                            struct wpabuf *nfc_dh_pubkey)
 698 {
 699         struct wpabuf *msg;
 700         void *len;
 701
 702         if (ctx == NULL)
 703                 return NULL;
 704
 705         wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 706                    "handover request");
 707
 708         if (nfc_dh_pubkey == NULL) {
 709                 wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 710                            "configured");
 711                 return NULL;
 712         }
 713
 714         msg = wpabuf_alloc(1000);
 715         if (msg == NULL)
 716                 return msg;
 717         len = wpabuf_put(msg, 2);
 718
 719         if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 720                                  nfc_dh_pubkey, NULL, 0) ||
 721             wps_build_uuid_e(msg, ctx->uuid) ||
 722             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 723                 wpabuf_free(msg);
 724                 return NULL;
 725         }
 726
 727         WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
 728
 729         return msg;
 730 }
 731
 732
 733 static int wps_build_ssid(struct wpabuf *msg, struct wps_context *wps)
 734 {
 735         wpa_printf(MSG_DEBUG, "WPS:  * SSID");
 736         wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID in Connection Handover Select",
 737                           wps->ssid, wps->ssid_len);
 738         wpabuf_put_be16(msg, ATTR_SSID);
 739         wpabuf_put_be16(msg, wps->ssid_len);
 740         wpabuf_put_data(msg, wps->ssid, wps->ssid_len);
 741         return 0;
 742 }
 743
 744
 745 static int wps_build_ap_freq(struct wpabuf *msg, int freq)
 746 {
 747         enum hostapd_hw_mode mode;
 748         u8 channel, rf_band;
 749         u16 ap_channel;
 750
 751         if (freq <= 0)
 752                 return 0;
 753
 754         mode = ieee80211_freq_to_chan(freq, &channel);
 755         if (mode == NUM_HOSTAPD_MODES)
 756                 return 0; /* Unknown channel */
 757
 758         if (mode == HOSTAPD_MODE_IEEE80211G || mode == HOSTAPD_MODE_IEEE80211B)
 759                 rf_band = WPS_RF_24GHZ;
 760         else if (mode == HOSTAPD_MODE_IEEE80211A)
 761                 rf_band = WPS_RF_50GHZ;
 762         else
 763                 return 0; /* Unknown band */
 764         ap_channel = channel;
 765
 766         if (wps_build_rf_bands_attr(msg, rf_band) ||
 767             wps_build_ap_channel(msg, ap_channel))
 768                 return -1;
 769
 770         return 0;
 771 }
 772
 773
 774 struct wpabuf * wps_build_nfc_handover_sel(struct wps_context *ctx,
 775                                            struct wpabuf *nfc_dh_pubkey,
 776                                            const u8 *bssid, int freq)
 777 {
 778         struct wpabuf *msg;
 779         void *len;
 780
 781         if (ctx == NULL)
 782                 return NULL;
 783
 784         wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 785                    "handover select");
 786
 787         if (nfc_dh_pubkey == NULL) {
 788                 wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 789                            "configured");
 790                 return NULL;
 791         }
 792
 793         msg = wpabuf_alloc(1000);
 794         if (msg == NULL)
 795                 return msg;
 796         len = wpabuf_put(msg, 2);
 797
 798         if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 799                                  nfc_dh_pubkey, NULL, 0) ||
 800             wps_build_ssid(msg, ctx) ||
 801             wps_build_ap_freq(msg, freq) ||
 802             (bssid && wps_build_mac_addr(msg, bssid)) ||
 803             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 804                 wpabuf_free(msg);
 805                 return NULL;
 806         }
 807
 808         WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
 809
 810         return msg;
 811 }
 812
 813
 814 struct wpabuf * wps_build_nfc_handover_req_p2p(struct wps_context *ctx,
 815                                                struct wpabuf *nfc_dh_pubkey)
 816 {
 817         struct wpabuf *msg;
 818
 819         if (ctx == NULL)
 820                 return NULL;
 821
 822         wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 823                    "handover request (P2P)");
 824
 825         if (nfc_dh_pubkey == NULL) {
 826                 wpa_printf(MSG_DEBUG, "WPS: No NFC DH Public Key configured");
 827                 return NULL;
 828         }
 829
 830         msg = wpabuf_alloc(1000);
 831         if (msg == NULL)
 832                 return msg;
 833
 834         if (wps_build_manufacturer(&ctx->dev, msg) ||
 835             wps_build_model_name(&ctx->dev, msg) ||
 836             wps_build_model_number(&ctx->dev, msg) ||
 837             wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 838                                  nfc_dh_pubkey, NULL, 0) ||
 839             wps_build_rf_bands(&ctx->dev, msg, 0) ||
 840             wps_build_serial_number(&ctx->dev, msg) ||
 841             wps_build_uuid_e(msg, ctx->uuid) ||
 842             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 843                 wpabuf_free(msg);
 844                 return NULL;
 845         }
 846
 847         return msg;
 848 }
 849
 850
 851 struct wpabuf * wps_build_nfc_handover_sel_p2p(struct wps_context *ctx,
 852                                                int nfc_dev_pw_id,
 853                                                struct wpabuf *nfc_dh_pubkey,
 854                                                struct wpabuf *nfc_dev_pw)
 855 {
 856         struct wpabuf *msg;
 857         const u8 *dev_pw;
 858         size_t dev_pw_len;
 859
 860         if (ctx == NULL)
 861                 return NULL;
 862
 863         wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 864                    "handover select (P2P)");
 865
 866         if (nfc_dh_pubkey == NULL ||
 867             (nfc_dev_pw_id != DEV_PW_NFC_CONNECTION_HANDOVER &&
 868              nfc_dev_pw == NULL)) {
 869                 wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 870                            "configured");
 871                 return NULL;
 872         }
 873
 874         msg = wpabuf_alloc(1000);
 875         if (msg == NULL)
 876                 return msg;
 877
 878         if (nfc_dev_pw) {
 879                 dev_pw = wpabuf_head(nfc_dev_pw);
 880                 dev_pw_len = wpabuf_len(nfc_dev_pw);
 881         } else {
 882                 dev_pw = NULL;
 883                 dev_pw_len = 0;
 884         }
 885
 886         if (wps_build_manufacturer(&ctx->dev, msg) ||
 887             wps_build_model_name(&ctx->dev, msg) ||
 888             wps_build_model_number(&ctx->dev, msg) ||
 889             wps_build_oob_dev_pw(msg, nfc_dev_pw_id, nfc_dh_pubkey,
 890                                  dev_pw, dev_pw_len) ||
 891             wps_build_rf_bands(&ctx->dev, msg, 0) ||
 892             wps_build_serial_number(&ctx->dev, msg) ||
 893             wps_build_uuid_e(msg, ctx->uuid) ||
 894             wps_build_wfa_ext(msg, 0, NULL, 0)) {
 895                 wpabuf_free(msg);
 896                 return NULL;
 897         }
 898
 899         return msg;
 900 }
 901
 902 #endif /* CONFIG_WPS_NFC */