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