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      1 /*
      2  * Wi-Fi Protected Setup - Enrollee
      3  * Copyright (c) 2008, Jouni Malinen <j (at) 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/crypto.h"
     13 #include "crypto/sha256.h"
     14 #include "crypto/random.h"
     15 #include "wps_i.h"
     16 #include "wps_dev_attr.h"
     17 
     18 
     19 static int wps_build_wps_state(struct wps_data *wps, struct wpabuf *msg)
     20 {
     21 	u8 state;
     22 	if (wps->wps->ap)
     23 		state = wps->wps->wps_state;
     24 	else
     25 		state = WPS_STATE_NOT_CONFIGURED;
     26 	wpa_printf(MSG_DEBUG, "WPS:  * Wi-Fi Protected Setup State (%d)",
     27 		   state);
     28 	wpabuf_put_be16(msg, ATTR_WPS_STATE);
     29 	wpabuf_put_be16(msg, 1);
     30 	wpabuf_put_u8(msg, state);
     31 	return 0;
     32 }
     33 
     34 
     35 static int wps_build_e_hash(struct wps_data *wps, struct wpabuf *msg)
     36 {
     37 	u8 *hash;
     38 	const u8 *addr[4];
     39 	size_t len[4];
     40 
     41 	if (random_get_bytes(wps->snonce, 2 * WPS_SECRET_NONCE_LEN) < 0)
     42 		return -1;
     43 	wpa_hexdump(MSG_DEBUG, "WPS: E-S1", wps->snonce, WPS_SECRET_NONCE_LEN);
     44 	wpa_hexdump(MSG_DEBUG, "WPS: E-S2",
     45 		    wps->snonce + WPS_SECRET_NONCE_LEN, WPS_SECRET_NONCE_LEN);
     46 
     47 	if (wps->dh_pubkey_e == NULL || wps->dh_pubkey_r == NULL) {
     48 		wpa_printf(MSG_DEBUG, "WPS: DH public keys not available for "
     49 			   "E-Hash derivation");
     50 		return -1;
     51 	}
     52 
     53 	wpa_printf(MSG_DEBUG, "WPS:  * E-Hash1");
     54 	wpabuf_put_be16(msg, ATTR_E_HASH1);
     55 	wpabuf_put_be16(msg, SHA256_MAC_LEN);
     56 	hash = wpabuf_put(msg, SHA256_MAC_LEN);
     57 	/* E-Hash1 = HMAC_AuthKey(E-S1 || PSK1 || PK_E || PK_R) */
     58 	addr[0] = wps->snonce;
     59 	len[0] = WPS_SECRET_NONCE_LEN;
     60 	addr[1] = wps->psk1;
     61 	len[1] = WPS_PSK_LEN;
     62 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
     63 	len[2] = wpabuf_len(wps->dh_pubkey_e);
     64 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
     65 	len[3] = wpabuf_len(wps->dh_pubkey_r);
     66 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
     67 	wpa_hexdump(MSG_DEBUG, "WPS: E-Hash1", hash, SHA256_MAC_LEN);
     68 
     69 	wpa_printf(MSG_DEBUG, "WPS:  * E-Hash2");
     70 	wpabuf_put_be16(msg, ATTR_E_HASH2);
     71 	wpabuf_put_be16(msg, SHA256_MAC_LEN);
     72 	hash = wpabuf_put(msg, SHA256_MAC_LEN);
     73 	/* E-Hash2 = HMAC_AuthKey(E-S2 || PSK2 || PK_E || PK_R) */
     74 	addr[0] = wps->snonce + WPS_SECRET_NONCE_LEN;
     75 	addr[1] = wps->psk2;
     76 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
     77 	wpa_hexdump(MSG_DEBUG, "WPS: E-Hash2", hash, SHA256_MAC_LEN);
     78 
     79 	return 0;
     80 }
     81 
     82 
     83 static int wps_build_e_snonce1(struct wps_data *wps, struct wpabuf *msg)
     84 {
     85 	wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce1");
     86 	wpabuf_put_be16(msg, ATTR_E_SNONCE1);
     87 	wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
     88 	wpabuf_put_data(msg, wps->snonce, WPS_SECRET_NONCE_LEN);
     89 	return 0;
     90 }
     91 
     92 
     93 static int wps_build_e_snonce2(struct wps_data *wps, struct wpabuf *msg)
     94 {
     95 	wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce2");
     96 	wpabuf_put_be16(msg, ATTR_E_SNONCE2);
     97 	wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
     98 	wpabuf_put_data(msg, wps->snonce + WPS_SECRET_NONCE_LEN,
     99 			WPS_SECRET_NONCE_LEN);
    100 	return 0;
    101 }
    102 
    103 
    104 static struct wpabuf * wps_build_m1(struct wps_data *wps)
    105 {
    106 	struct wpabuf *msg;
    107 	u16 config_methods;
    108 
    109 	if (random_get_bytes(wps->nonce_e, WPS_NONCE_LEN) < 0)
    110 		return NULL;
    111 	wpa_hexdump(MSG_DEBUG, "WPS: Enrollee Nonce",
    112 		    wps->nonce_e, WPS_NONCE_LEN);
    113 
    114 	wpa_printf(MSG_DEBUG, "WPS: Building Message M1");
    115 	msg = wpabuf_alloc(1000);
    116 	if (msg == NULL)
    117 		return NULL;
    118 
    119 	config_methods = wps->wps->config_methods;
    120 	if (wps->wps->ap && !wps->pbc_in_m1 &&
    121 	    (wps->dev_password_len != 0 ||
    122 	     (config_methods & WPS_CONFIG_DISPLAY))) {
    123 		/*
    124 		 * These are the methods that the AP supports as an Enrollee
    125 		 * for adding external Registrars, so remove PushButton.
    126 		 *
    127 		 * As a workaround for Windows 7 mechanism for probing WPS
    128 		 * capabilities from M1, leave PushButton option if no PIN
    129 		 * method is available or if WPS configuration enables PBC
    130 		 * workaround.
    131 		 */
    132 		config_methods &= ~WPS_CONFIG_PUSHBUTTON;
    133 		config_methods &= ~(WPS_CONFIG_VIRT_PUSHBUTTON |
    134 				    WPS_CONFIG_PHY_PUSHBUTTON);
    135 	}
    136 
    137 	if (wps_build_version(msg) ||
    138 	    wps_build_msg_type(msg, WPS_M1) ||
    139 	    wps_build_uuid_e(msg, wps->uuid_e) ||
    140 	    wps_build_mac_addr(msg, wps->mac_addr_e) ||
    141 	    wps_build_enrollee_nonce(wps, msg) ||
    142 	    wps_build_public_key(wps, msg) ||
    143 	    wps_build_auth_type_flags(wps, msg) ||
    144 	    wps_build_encr_type_flags(wps, msg) ||
    145 	    wps_build_conn_type_flags(wps, msg) ||
    146 	    wps_build_config_methods(msg, config_methods) ||
    147 	    wps_build_wps_state(wps, msg) ||
    148 	    wps_build_device_attrs(&wps->wps->dev, msg) ||
    149 	    wps_build_rf_bands(&wps->wps->dev, msg,
    150 			       wps->wps->rf_band_cb(wps->wps->cb_ctx)) ||
    151 	    wps_build_assoc_state(wps, msg) ||
    152 	    wps_build_dev_password_id(msg, wps->dev_pw_id) ||
    153 	    wps_build_config_error(msg, WPS_CFG_NO_ERROR) ||
    154 	    wps_build_os_version(&wps->wps->dev, msg) ||
    155 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
    156 	    wps_build_vendor_ext_m1(&wps->wps->dev, msg)) {
    157 		wpabuf_free(msg);
    158 		return NULL;
    159 	}
    160 
    161 	wps->state = RECV_M2;
    162 	return msg;
    163 }
    164 
    165 
    166 static struct wpabuf * wps_build_m3(struct wps_data *wps)
    167 {
    168 	struct wpabuf *msg;
    169 
    170 	wpa_printf(MSG_DEBUG, "WPS: Building Message M3");
    171 
    172 	if (wps->dev_password == NULL) {
    173 		wpa_printf(MSG_DEBUG, "WPS: No Device Password available");
    174 		return NULL;
    175 	}
    176 	if (wps_derive_psk(wps, wps->dev_password, wps->dev_password_len) < 0)
    177 		return NULL;
    178 
    179 	if (wps->wps->ap && random_pool_ready() != 1) {
    180 		wpa_printf(MSG_INFO,
    181 			   "WPS: Not enough entropy in random pool to proceed - do not allow AP PIN to be used");
    182 		return NULL;
    183 	}
    184 
    185 	msg = wpabuf_alloc(1000);
    186 	if (msg == NULL)
    187 		return NULL;
    188 
    189 	if (wps_build_version(msg) ||
    190 	    wps_build_msg_type(msg, WPS_M3) ||
    191 	    wps_build_registrar_nonce(wps, msg) ||
    192 	    wps_build_e_hash(wps, msg) ||
    193 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
    194 	    wps_build_authenticator(wps, msg)) {
    195 		wpabuf_free(msg);
    196 		return NULL;
    197 	}
    198 
    199 	wps->state = RECV_M4;
    200 	return msg;
    201 }
    202 
    203 
    204 static struct wpabuf * wps_build_m5(struct wps_data *wps)
    205 {
    206 	struct wpabuf *msg, *plain;
    207 
    208 	wpa_printf(MSG_DEBUG, "WPS: Building Message M5");
    209 
    210 	plain = wpabuf_alloc(200);
    211 	if (plain == NULL)
    212 		return NULL;
    213 
    214 	msg = wpabuf_alloc(1000);
    215 	if (msg == NULL) {
    216 		wpabuf_free(plain);
    217 		return NULL;
    218 	}
    219 
    220 	if (wps_build_version(msg) ||
    221 	    wps_build_msg_type(msg, WPS_M5) ||
    222 	    wps_build_registrar_nonce(wps, msg) ||
    223 	    wps_build_e_snonce1(wps, plain) ||
    224 	    wps_build_key_wrap_auth(wps, plain) ||
    225 	    wps_build_encr_settings(wps, msg, plain) ||
    226 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
    227 	    wps_build_authenticator(wps, msg)) {
    228 		wpabuf_clear_free(plain);
    229 		wpabuf_free(msg);
    230 		return NULL;
    231 	}
    232 	wpabuf_clear_free(plain);
    233 
    234 	wps->state = RECV_M6;
    235 	return msg;
    236 }
    237 
    238 
    239 static int wps_build_cred_ssid(struct wps_data *wps, struct wpabuf *msg)
    240 {
    241 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
    242 	wpabuf_put_be16(msg, ATTR_SSID);
    243 	wpabuf_put_be16(msg, wps->wps->ssid_len);
    244 	wpabuf_put_data(msg, wps->wps->ssid, wps->wps->ssid_len);
    245 	return 0;
    246 }
    247 
    248 
    249 static int wps_build_cred_auth_type(struct wps_data *wps, struct wpabuf *msg)
    250 {
    251 	u16 auth_type = wps->wps->ap_auth_type;
    252 
    253 	/*
    254 	 * Work around issues with Windows 7 WPS implementation not liking
    255 	 * multiple Authentication Type bits in M7 AP Settings attribute by
    256 	 * showing only the most secure option from current configuration.
    257 	 */
    258 	if (auth_type & WPS_AUTH_WPA2PSK)
    259 		auth_type = WPS_AUTH_WPA2PSK;
    260 	else if (auth_type & WPS_AUTH_WPAPSK)
    261 		auth_type = WPS_AUTH_WPAPSK;
    262 	else if (auth_type & WPS_AUTH_OPEN)
    263 		auth_type = WPS_AUTH_OPEN;
    264 
    265 	wpa_printf(MSG_DEBUG, "WPS:  * Authentication Type (0x%x)", auth_type);
    266 	wpabuf_put_be16(msg, ATTR_AUTH_TYPE);
    267 	wpabuf_put_be16(msg, 2);
    268 	wpabuf_put_be16(msg, auth_type);
    269 	return 0;
    270 }
    271 
    272 
    273 static int wps_build_cred_encr_type(struct wps_data *wps, struct wpabuf *msg)
    274 {
    275 	u16 encr_type = wps->wps->ap_encr_type;
    276 
    277 	/*
    278 	 * Work around issues with Windows 7 WPS implementation not liking
    279 	 * multiple Encryption Type bits in M7 AP Settings attribute by
    280 	 * showing only the most secure option from current configuration.
    281 	 */
    282 	if (wps->wps->ap_auth_type & (WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK)) {
    283 		if (encr_type & WPS_ENCR_AES)
    284 			encr_type = WPS_ENCR_AES;
    285 		else if (encr_type & WPS_ENCR_TKIP)
    286 			encr_type = WPS_ENCR_TKIP;
    287 	}
    288 
    289 	wpa_printf(MSG_DEBUG, "WPS:  * Encryption Type (0x%x)", encr_type);
    290 	wpabuf_put_be16(msg, ATTR_ENCR_TYPE);
    291 	wpabuf_put_be16(msg, 2);
    292 	wpabuf_put_be16(msg, encr_type);
    293 	return 0;
    294 }
    295 
    296 
    297 static int wps_build_cred_network_key(struct wps_data *wps, struct wpabuf *msg)
    298 {
    299 	if ((wps->wps->ap_auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) &&
    300 	    wps->wps->network_key_len == 0) {
    301 		char hex[65];
    302 		u8 psk[32];
    303 		/* Generate a random per-device PSK */
    304 		if (random_pool_ready() != 1 ||
    305 		    random_get_bytes(psk, sizeof(psk)) < 0) {
    306 			wpa_printf(MSG_INFO,
    307 				   "WPS: Could not generate random PSK");
    308 			return -1;
    309 		}
    310 		wpa_hexdump_key(MSG_DEBUG, "WPS: Generated per-device PSK",
    311 				psk, sizeof(psk));
    312 		wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
    313 			   (unsigned int) wps->new_psk_len * 2);
    314 		wpa_snprintf_hex(hex, sizeof(hex), psk, sizeof(psk));
    315 		wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
    316 		wpabuf_put_be16(msg, sizeof(psk) * 2);
    317 		wpabuf_put_data(msg, hex, sizeof(psk) * 2);
    318 		if (wps->wps->registrar) {
    319 			wps_cb_new_psk(wps->wps->registrar,
    320 				       wps->peer_dev.mac_addr,
    321 				       wps->p2p_dev_addr, psk, sizeof(psk));
    322 		}
    323 		return 0;
    324 	}
    325 
    326 	wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
    327 		   (unsigned int) wps->wps->network_key_len);
    328 	wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
    329 	wpabuf_put_be16(msg, wps->wps->network_key_len);
    330 	wpabuf_put_data(msg, wps->wps->network_key, wps->wps->network_key_len);
    331 	return 0;
    332 }
    333 
    334 
    335 static int wps_build_cred_mac_addr(struct wps_data *wps, struct wpabuf *msg)
    336 {
    337 	wpa_printf(MSG_DEBUG, "WPS:  * MAC Address (AP BSSID)");
    338 	wpabuf_put_be16(msg, ATTR_MAC_ADDR);
    339 	wpabuf_put_be16(msg, ETH_ALEN);
    340 	wpabuf_put_data(msg, wps->wps->dev.mac_addr, ETH_ALEN);
    341 	return 0;
    342 }
    343 
    344 
    345 static int wps_build_ap_settings(struct wps_data *wps, struct wpabuf *plain)
    346 {
    347 	const u8 *start, *end;
    348 	int ret;
    349 
    350 	if (wps->wps->ap_settings) {
    351 		wpa_printf(MSG_DEBUG, "WPS:  * AP Settings (pre-configured)");
    352 		wpabuf_put_data(plain, wps->wps->ap_settings,
    353 				wps->wps->ap_settings_len);
    354 		return 0;
    355 	}
    356 
    357 	wpa_printf(MSG_DEBUG, "WPS:  * AP Settings based on current configuration");
    358 	start = wpabuf_put(plain, 0);
    359 	ret = wps_build_cred_ssid(wps, plain) ||
    360 		wps_build_cred_mac_addr(wps, plain) ||
    361 		wps_build_cred_auth_type(wps, plain) ||
    362 		wps_build_cred_encr_type(wps, plain) ||
    363 		wps_build_cred_network_key(wps, plain);
    364 	end = wpabuf_put(plain, 0);
    365 
    366 	wpa_hexdump_key(MSG_DEBUG, "WPS: Plaintext AP Settings",
    367 			start, end - start);
    368 
    369 	return ret;
    370 }
    371 
    372 
    373 static struct wpabuf * wps_build_m7(struct wps_data *wps)
    374 {
    375 	struct wpabuf *msg, *plain;
    376 
    377 	wpa_printf(MSG_DEBUG, "WPS: Building Message M7");
    378 
    379 	plain = wpabuf_alloc(500 + wps->wps->ap_settings_len);
    380 	if (plain == NULL)
    381 		return NULL;
    382 
    383 	msg = wpabuf_alloc(1000 + wps->wps->ap_settings_len);
    384 	if (msg == NULL) {
    385 		wpabuf_free(plain);
    386 		return NULL;
    387 	}
    388 
    389 	if (wps_build_version(msg) ||
    390 	    wps_build_msg_type(msg, WPS_M7) ||
    391 	    wps_build_registrar_nonce(wps, msg) ||
    392 	    wps_build_e_snonce2(wps, plain) ||
    393 	    (wps->wps->ap && wps_build_ap_settings(wps, plain)) ||
    394 	    wps_build_key_wrap_auth(wps, plain) ||
    395 	    wps_build_encr_settings(wps, msg, plain) ||
    396 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
    397 	    wps_build_authenticator(wps, msg)) {
    398 		wpabuf_clear_free(plain);
    399 		wpabuf_free(msg);
    400 		return NULL;
    401 	}
    402 	wpabuf_clear_free(plain);
    403 
    404 	if (wps->wps->ap && wps->wps->registrar) {
    405 		/*
    406 		 * If the Registrar is only learning our current configuration,
    407 		 * it may not continue protocol run to successful completion.
    408 		 * Store information here to make sure it remains available.
    409 		 */
    410 		wps_device_store(wps->wps->registrar, &wps->peer_dev,
    411 				 wps->uuid_r);
    412 	}
    413 
    414 	wps->state = RECV_M8;
    415 	return msg;
    416 }
    417 
    418 
    419 static struct wpabuf * wps_build_wsc_done(struct wps_data *wps)
    420 {
    421 	struct wpabuf *msg;
    422 
    423 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_Done");
    424 
    425 	msg = wpabuf_alloc(1000);
    426 	if (msg == NULL)
    427 		return NULL;
    428 
    429 	if (wps_build_version(msg) ||
    430 	    wps_build_msg_type(msg, WPS_WSC_DONE) ||
    431 	    wps_build_enrollee_nonce(wps, msg) ||
    432 	    wps_build_registrar_nonce(wps, msg) ||
    433 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
    434 		wpabuf_free(msg);
    435 		return NULL;
    436 	}
    437 
    438 	if (wps->wps->ap)
    439 		wps->state = RECV_ACK;
    440 	else {
    441 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
    442 		wps->state = WPS_FINISHED;
    443 	}
    444 	return msg;
    445 }
    446 
    447 
    448 struct wpabuf * wps_enrollee_get_msg(struct wps_data *wps,
    449 				     enum wsc_op_code *op_code)
    450 {
    451 	struct wpabuf *msg;
    452 
    453 	switch (wps->state) {
    454 	case SEND_M1:
    455 		msg = wps_build_m1(wps);
    456 		*op_code = WSC_MSG;
    457 		break;
    458 	case SEND_M3:
    459 		msg = wps_build_m3(wps);
    460 		*op_code = WSC_MSG;
    461 		break;
    462 	case SEND_M5:
    463 		msg = wps_build_m5(wps);
    464 		*op_code = WSC_MSG;
    465 		break;
    466 	case SEND_M7:
    467 		msg = wps_build_m7(wps);
    468 		*op_code = WSC_MSG;
    469 		break;
    470 	case RECEIVED_M2D:
    471 		if (wps->wps->ap) {
    472 			msg = wps_build_wsc_nack(wps);
    473 			*op_code = WSC_NACK;
    474 			break;
    475 		}
    476 		msg = wps_build_wsc_ack(wps);
    477 		*op_code = WSC_ACK;
    478 		if (msg) {
    479 			/* Another M2/M2D may be received */
    480 			wps->state = RECV_M2;
    481 		}
    482 		break;
    483 	case SEND_WSC_NACK:
    484 		msg = wps_build_wsc_nack(wps);
    485 		*op_code = WSC_NACK;
    486 		break;
    487 	case WPS_MSG_DONE:
    488 		msg = wps_build_wsc_done(wps);
    489 		*op_code = WSC_Done;
    490 		break;
    491 	default:
    492 		wpa_printf(MSG_DEBUG, "WPS: Unsupported state %d for building "
    493 			   "a message", wps->state);
    494 		msg = NULL;
    495 		break;
    496 	}
    497 
    498 	if (*op_code == WSC_MSG && msg) {
    499 		/* Save a copy of the last message for Authenticator derivation
    500 		 */
    501 		wpabuf_free(wps->last_msg);
    502 		wps->last_msg = wpabuf_dup(msg);
    503 	}
    504 
    505 	return msg;
    506 }
    507 
    508 
    509 static int wps_process_registrar_nonce(struct wps_data *wps, const u8 *r_nonce)
    510 {
    511 	if (r_nonce == NULL) {
    512 		wpa_printf(MSG_DEBUG, "WPS: No Registrar Nonce received");
    513 		return -1;
    514 	}
    515 
    516 	os_memcpy(wps->nonce_r, r_nonce, WPS_NONCE_LEN);
    517 	wpa_hexdump(MSG_DEBUG, "WPS: Registrar Nonce",
    518 		    wps->nonce_r, WPS_NONCE_LEN);
    519 
    520 	return 0;
    521 }
    522 
    523 
    524 static int wps_process_enrollee_nonce(struct wps_data *wps, const u8 *e_nonce)
    525 {
    526 	if (e_nonce == NULL) {
    527 		wpa_printf(MSG_DEBUG, "WPS: No Enrollee Nonce received");
    528 		return -1;
    529 	}
    530 
    531 	if (os_memcmp(wps->nonce_e, e_nonce, WPS_NONCE_LEN) != 0) {
    532 		wpa_printf(MSG_DEBUG, "WPS: Invalid Enrollee Nonce received");
    533 		return -1;
    534 	}
    535 
    536 	return 0;
    537 }
    538 
    539 
    540 static int wps_process_uuid_r(struct wps_data *wps, const u8 *uuid_r)
    541 {
    542 	if (uuid_r == NULL) {
    543 		wpa_printf(MSG_DEBUG, "WPS: No UUID-R received");
    544 		return -1;
    545 	}
    546 
    547 	os_memcpy(wps->uuid_r, uuid_r, WPS_UUID_LEN);
    548 	wpa_hexdump(MSG_DEBUG, "WPS: UUID-R", wps->uuid_r, WPS_UUID_LEN);
    549 
    550 	return 0;
    551 }
    552 
    553 
    554 static int wps_process_pubkey(struct wps_data *wps, const u8 *pk,
    555 			      size_t pk_len)
    556 {
    557 	if (pk == NULL || pk_len == 0) {
    558 		wpa_printf(MSG_DEBUG, "WPS: No Public Key received");
    559 		return -1;
    560 	}
    561 
    562 	if (wps->peer_pubkey_hash_set) {
    563 		u8 hash[WPS_HASH_LEN];
    564 		sha256_vector(1, &pk, &pk_len, hash);
    565 		if (os_memcmp_const(hash, wps->peer_pubkey_hash,
    566 				    WPS_OOB_PUBKEY_HASH_LEN) != 0) {
    567 			wpa_printf(MSG_ERROR, "WPS: Public Key hash mismatch");
    568 			wpa_hexdump(MSG_DEBUG, "WPS: Received public key",
    569 				    pk, pk_len);
    570 			wpa_hexdump(MSG_DEBUG, "WPS: Calculated public key "
    571 				    "hash", hash, WPS_OOB_PUBKEY_HASH_LEN);
    572 			wpa_hexdump(MSG_DEBUG, "WPS: Expected public key hash",
    573 				    wps->peer_pubkey_hash,
    574 				    WPS_OOB_PUBKEY_HASH_LEN);
    575 			wps->config_error = WPS_CFG_PUBLIC_KEY_HASH_MISMATCH;
    576 			return -1;
    577 		}
    578 	}
    579 
    580 	wpabuf_free(wps->dh_pubkey_r);
    581 	wps->dh_pubkey_r = wpabuf_alloc_copy(pk, pk_len);
    582 	if (wps->dh_pubkey_r == NULL)
    583 		return -1;
    584 
    585 	if (wps_derive_keys(wps) < 0)
    586 		return -1;
    587 
    588 	return 0;
    589 }
    590 
    591 
    592 static int wps_process_r_hash1(struct wps_data *wps, const u8 *r_hash1)
    593 {
    594 	if (r_hash1 == NULL) {
    595 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash1 received");
    596 		return -1;
    597 	}
    598 
    599 	os_memcpy(wps->peer_hash1, r_hash1, WPS_HASH_LEN);
    600 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash1", wps->peer_hash1, WPS_HASH_LEN);
    601 
    602 	return 0;
    603 }
    604 
    605 
    606 static int wps_process_r_hash2(struct wps_data *wps, const u8 *r_hash2)
    607 {
    608 	if (r_hash2 == NULL) {
    609 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash2 received");
    610 		return -1;
    611 	}
    612 
    613 	os_memcpy(wps->peer_hash2, r_hash2, WPS_HASH_LEN);
    614 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash2", wps->peer_hash2, WPS_HASH_LEN);
    615 
    616 	return 0;
    617 }
    618 
    619 
    620 static int wps_process_r_snonce1(struct wps_data *wps, const u8 *r_snonce1)
    621 {
    622 	u8 hash[SHA256_MAC_LEN];
    623 	const u8 *addr[4];
    624 	size_t len[4];
    625 
    626 	if (r_snonce1 == NULL) {
    627 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce1 received");
    628 		return -1;
    629 	}
    630 
    631 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce1", r_snonce1,
    632 			WPS_SECRET_NONCE_LEN);
    633 
    634 	/* R-Hash1 = HMAC_AuthKey(R-S1 || PSK1 || PK_E || PK_R) */
    635 	addr[0] = r_snonce1;
    636 	len[0] = WPS_SECRET_NONCE_LEN;
    637 	addr[1] = wps->psk1;
    638 	len[1] = WPS_PSK_LEN;
    639 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
    640 	len[2] = wpabuf_len(wps->dh_pubkey_e);
    641 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
    642 	len[3] = wpabuf_len(wps->dh_pubkey_r);
    643 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
    644 
    645 	if (os_memcmp_const(wps->peer_hash1, hash, WPS_HASH_LEN) != 0) {
    646 		wpa_printf(MSG_DEBUG, "WPS: R-Hash1 derived from R-S1 does "
    647 			   "not match with the pre-committed value");
    648 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
    649 		wps_pwd_auth_fail_event(wps->wps, 1, 1, wps->peer_dev.mac_addr);
    650 		return -1;
    651 	}
    652 
    653 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the first "
    654 		   "half of the device password");
    655 
    656 	return 0;
    657 }
    658 
    659 
    660 static int wps_process_r_snonce2(struct wps_data *wps, const u8 *r_snonce2)
    661 {
    662 	u8 hash[SHA256_MAC_LEN];
    663 	const u8 *addr[4];
    664 	size_t len[4];
    665 
    666 	if (r_snonce2 == NULL) {
    667 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce2 received");
    668 		return -1;
    669 	}
    670 
    671 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce2", r_snonce2,
    672 			WPS_SECRET_NONCE_LEN);
    673 
    674 	/* R-Hash2 = HMAC_AuthKey(R-S2 || PSK2 || PK_E || PK_R) */
    675 	addr[0] = r_snonce2;
    676 	len[0] = WPS_SECRET_NONCE_LEN;
    677 	addr[1] = wps->psk2;
    678 	len[1] = WPS_PSK_LEN;
    679 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
    680 	len[2] = wpabuf_len(wps->dh_pubkey_e);
    681 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
    682 	len[3] = wpabuf_len(wps->dh_pubkey_r);
    683 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
    684 
    685 	if (os_memcmp_const(wps->peer_hash2, hash, WPS_HASH_LEN) != 0) {
    686 		wpa_printf(MSG_DEBUG, "WPS: R-Hash2 derived from R-S2 does "
    687 			   "not match with the pre-committed value");
    688 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
    689 		wps_pwd_auth_fail_event(wps->wps, 1, 2, wps->peer_dev.mac_addr);
    690 		return -1;
    691 	}
    692 
    693 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the second "
    694 		   "half of the device password");
    695 
    696 	return 0;
    697 }
    698 
    699 
    700 static int wps_process_cred_e(struct wps_data *wps, const u8 *cred,
    701 			      size_t cred_len, int wps2)
    702 {
    703 	struct wps_parse_attr attr;
    704 	struct wpabuf msg;
    705 	int ret = 0;
    706 
    707 	wpa_printf(MSG_DEBUG, "WPS: Received Credential");
    708 	os_memset(&wps->cred, 0, sizeof(wps->cred));
    709 	wpabuf_set(&msg, cred, cred_len);
    710 	if (wps_parse_msg(&msg, &attr) < 0 ||
    711 	    wps_process_cred(&attr, &wps->cred))
    712 		return -1;
    713 
    714 	if (os_memcmp(wps->cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
    715 	    0) {
    716 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the Credential ("
    717 			   MACSTR ") does not match with own address (" MACSTR
    718 			   ")", MAC2STR(wps->cred.mac_addr),
    719 			   MAC2STR(wps->wps->dev.mac_addr));
    720 		/*
    721 		 * In theory, this could be consider fatal error, but there are
    722 		 * number of deployed implementations using other address here
    723 		 * due to unclarity in the specification. For interoperability
    724 		 * reasons, allow this to be processed since we do not really
    725 		 * use the MAC Address information for anything.
    726 		 */
    727 #ifdef CONFIG_WPS_STRICT
    728 		if (wps2) {
    729 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
    730 				   "MAC Address in AP Settings");
    731 			return -1;
    732 		}
    733 #endif /* CONFIG_WPS_STRICT */
    734 	}
    735 
    736 	if (!(wps->cred.encr_type &
    737 	      (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES))) {
    738 		if (wps->cred.encr_type & WPS_ENCR_WEP) {
    739 			wpa_printf(MSG_INFO, "WPS: Reject Credential "
    740 				   "due to WEP configuration");
    741 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
    742 			return -2;
    743 		}
    744 
    745 		wpa_printf(MSG_INFO, "WPS: Reject Credential due to "
    746 			   "invalid encr_type 0x%x", wps->cred.encr_type);
    747 		return -1;
    748 	}
    749 
    750 	if (wps->wps->cred_cb) {
    751 		wps->cred.cred_attr = cred - 4;
    752 		wps->cred.cred_attr_len = cred_len + 4;
    753 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &wps->cred);
    754 		wps->cred.cred_attr = NULL;
    755 		wps->cred.cred_attr_len = 0;
    756 	}
    757 
    758 	return ret;
    759 }
    760 
    761 
    762 static int wps_process_creds(struct wps_data *wps, const u8 *cred[],
    763 			     u16 cred_len[], unsigned int num_cred, int wps2)
    764 {
    765 	size_t i;
    766 	int ok = 0;
    767 
    768 	if (wps->wps->ap)
    769 		return 0;
    770 
    771 	if (num_cred == 0) {
    772 		wpa_printf(MSG_DEBUG, "WPS: No Credential attributes "
    773 			   "received");
    774 		return -1;
    775 	}
    776 
    777 	for (i = 0; i < num_cred; i++) {
    778 		int res;
    779 		res = wps_process_cred_e(wps, cred[i], cred_len[i], wps2);
    780 		if (res == 0)
    781 			ok++;
    782 		else if (res == -2)
    783 			wpa_printf(MSG_DEBUG, "WPS: WEP credential skipped");
    784 		else
    785 			return -1;
    786 	}
    787 
    788 	if (ok == 0) {
    789 		wpa_printf(MSG_DEBUG, "WPS: No valid Credential attribute "
    790 			   "received");
    791 		return -1;
    792 	}
    793 
    794 	return 0;
    795 }
    796 
    797 
    798 static int wps_process_ap_settings_e(struct wps_data *wps,
    799 				     struct wps_parse_attr *attr,
    800 				     struct wpabuf *attrs, int wps2)
    801 {
    802 	struct wps_credential cred;
    803 	int ret = 0;
    804 
    805 	if (!wps->wps->ap)
    806 		return 0;
    807 
    808 	if (wps_process_ap_settings(attr, &cred) < 0)
    809 		return -1;
    810 
    811 	wpa_printf(MSG_INFO, "WPS: Received new AP configuration from "
    812 		   "Registrar");
    813 
    814 	if (os_memcmp(cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
    815 	    0) {
    816 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the AP Settings ("
    817 			   MACSTR ") does not match with own address (" MACSTR
    818 			   ")", MAC2STR(cred.mac_addr),
    819 			   MAC2STR(wps->wps->dev.mac_addr));
    820 		/*
    821 		 * In theory, this could be consider fatal error, but there are
    822 		 * number of deployed implementations using other address here
    823 		 * due to unclarity in the specification. For interoperability
    824 		 * reasons, allow this to be processed since we do not really
    825 		 * use the MAC Address information for anything.
    826 		 */
    827 #ifdef CONFIG_WPS_STRICT
    828 		if (wps2) {
    829 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
    830 				   "MAC Address in AP Settings");
    831 			return -1;
    832 		}
    833 #endif /* CONFIG_WPS_STRICT */
    834 	}
    835 
    836 	if (!(cred.encr_type & (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES)))
    837 	{
    838 		if (cred.encr_type & WPS_ENCR_WEP) {
    839 			wpa_printf(MSG_INFO, "WPS: Reject new AP settings "
    840 				   "due to WEP configuration");
    841 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
    842 			return -1;
    843 		}
    844 
    845 		wpa_printf(MSG_INFO, "WPS: Reject new AP settings due to "
    846 			   "invalid encr_type 0x%x", cred.encr_type);
    847 		return -1;
    848 	}
    849 
    850 #ifdef CONFIG_WPS_STRICT
    851 	if (wps2) {
    852 		if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) ==
    853 		    WPS_ENCR_TKIP ||
    854 		    (cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
    855 		    WPS_AUTH_WPAPSK) {
    856 			wpa_printf(MSG_INFO, "WPS-STRICT: Invalid WSC 2.0 "
    857 				   "AP Settings: WPA-Personal/TKIP only");
    858 			wps->error_indication =
    859 				WPS_EI_SECURITY_TKIP_ONLY_PROHIBITED;
    860 			return -1;
    861 		}
    862 	}
    863 #endif /* CONFIG_WPS_STRICT */
    864 
    865 	if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) == WPS_ENCR_TKIP)
    866 	{
    867 		wpa_printf(MSG_DEBUG, "WPS: Upgrade encr_type TKIP -> "
    868 			   "TKIP+AES");
    869 		cred.encr_type |= WPS_ENCR_AES;
    870 	}
    871 
    872 	if ((cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
    873 	    WPS_AUTH_WPAPSK) {
    874 		wpa_printf(MSG_DEBUG, "WPS: Upgrade auth_type WPAPSK -> "
    875 			   "WPAPSK+WPA2PSK");
    876 		cred.auth_type |= WPS_AUTH_WPA2PSK;
    877 	}
    878 
    879 	if (wps->wps->cred_cb) {
    880 		cred.cred_attr = wpabuf_head(attrs);
    881 		cred.cred_attr_len = wpabuf_len(attrs);
    882 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &cred);
    883 	}
    884 
    885 	return ret;
    886 }
    887 
    888 
    889 static int wps_process_dev_pw_id(struct wps_data *wps, const u8 *dev_pw_id)
    890 {
    891 	u16 id;
    892 
    893 	if (dev_pw_id == NULL) {
    894 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID");
    895 		return -1;
    896 	}
    897 
    898 	id = WPA_GET_BE16(dev_pw_id);
    899 	if (wps->dev_pw_id == id) {
    900 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID %u", id);
    901 		return 0;
    902 	}
    903 
    904 #ifdef CONFIG_P2P
    905 	if ((id == DEV_PW_DEFAULT &&
    906 	     wps->dev_pw_id == DEV_PW_REGISTRAR_SPECIFIED) ||
    907 	    (id == DEV_PW_REGISTRAR_SPECIFIED &&
    908 	     wps->dev_pw_id == DEV_PW_DEFAULT)) {
    909 		/*
    910 		 * Common P2P use cases indicate whether the PIN is from the
    911 		 * client or GO using Device Password Id in M1/M2 in a way that
    912 		 * does not look fully compliant with WSC specification. Anyway,
    913 		 * this is deployed and needs to be allowed, so ignore changes
    914 		 * between Registrar-Specified and Default PIN.
    915 		 */
    916 		wpa_printf(MSG_DEBUG, "WPS: Allow PIN Device Password ID "
    917 			   "change");
    918 		return 0;
    919 	}
    920 #endif /* CONFIG_P2P */
    921 
    922 	wpa_printf(MSG_DEBUG, "WPS: Registrar trying to change Device Password "
    923 		   "ID from %u to %u", wps->dev_pw_id, id);
    924 
    925 	if (wps->dev_pw_id == DEV_PW_PUSHBUTTON && id == DEV_PW_DEFAULT) {
    926 		wpa_printf(MSG_DEBUG,
    927 			   "WPS: Workaround - ignore PBC-to-PIN change");
    928 		return 0;
    929 	}
    930 
    931 	if (wps->alt_dev_password && wps->alt_dev_pw_id == id) {
    932 		wpa_printf(MSG_DEBUG, "WPS: Found a matching Device Password");
    933 		bin_clear_free(wps->dev_password, wps->dev_password_len);
    934 		wps->dev_pw_id = wps->alt_dev_pw_id;
    935 		wps->dev_password = wps->alt_dev_password;
    936 		wps->dev_password_len = wps->alt_dev_password_len;
    937 		wps->alt_dev_password = NULL;
    938 		wps->alt_dev_password_len = 0;
    939 		return 0;
    940 	}
    941 
    942 	return -1;
    943 }
    944 
    945 
    946 static enum wps_process_res wps_process_m2(struct wps_data *wps,
    947 					   const struct wpabuf *msg,
    948 					   struct wps_parse_attr *attr)
    949 {
    950 	wpa_printf(MSG_DEBUG, "WPS: Received M2");
    951 
    952 	if (wps->state != RECV_M2) {
    953 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
    954 			   "receiving M2", wps->state);
    955 		wps->state = SEND_WSC_NACK;
    956 		return WPS_CONTINUE;
    957 	}
    958 
    959 	if (wps_process_registrar_nonce(wps, attr->registrar_nonce) ||
    960 	    wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
    961 	    wps_process_uuid_r(wps, attr->uuid_r) ||
    962 	    wps_process_dev_pw_id(wps, attr->dev_password_id)) {
    963 		wps->state = SEND_WSC_NACK;
    964 		return WPS_CONTINUE;
    965 	}
    966 
    967 	/*
    968 	 * Stop here on an AP as an Enrollee if AP Setup is locked unless the
    969 	 * special locked mode is used to allow protocol run up to M7 in order
    970 	 * to support external Registrars that only learn the current AP
    971 	 * configuration without changing it.
    972 	 */
    973 	if (wps->wps->ap &&
    974 	    ((wps->wps->ap_setup_locked && wps->wps->ap_setup_locked != 2) ||
    975 	     wps->dev_password == NULL)) {
    976 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
    977 			   "registration of a new Registrar");
    978 		wps->config_error = WPS_CFG_SETUP_LOCKED;
    979 		wps->state = SEND_WSC_NACK;
    980 		return WPS_CONTINUE;
    981 	}
    982 
    983 	if (wps_process_pubkey(wps, attr->public_key, attr->public_key_len) ||
    984 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
    985 	    wps_process_device_attrs(&wps->peer_dev, attr)) {
    986 		wps->state = SEND_WSC_NACK;
    987 		return WPS_CONTINUE;
    988 	}
    989 
    990 #ifdef CONFIG_WPS_NFC
    991 	if (wps->peer_pubkey_hash_set) {
    992 		struct wpabuf *decrypted;
    993 		struct wps_parse_attr eattr;
    994 
    995 		decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
    996 						      attr->encr_settings_len);
    997 		if (decrypted == NULL) {
    998 			wpa_printf(MSG_DEBUG, "WPS: Failed to decrypt "
    999 				   "Encrypted Settings attribute");
   1000 			wps->state = SEND_WSC_NACK;
   1001 			return WPS_CONTINUE;
   1002 		}
   1003 
   1004 		wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted "
   1005 			   "Settings attribute");
   1006 		if (wps_parse_msg(decrypted, &eattr) < 0 ||
   1007 		    wps_process_key_wrap_auth(wps, decrypted,
   1008 					      eattr.key_wrap_auth) ||
   1009 		    wps_process_creds(wps, eattr.cred, eattr.cred_len,
   1010 				      eattr.num_cred, attr->version2 != NULL)) {
   1011 			wpabuf_clear_free(decrypted);
   1012 			wps->state = SEND_WSC_NACK;
   1013 			return WPS_CONTINUE;
   1014 		}
   1015 		wpabuf_clear_free(decrypted);
   1016 
   1017 		wps->state = WPS_MSG_DONE;
   1018 		return WPS_CONTINUE;
   1019 	}
   1020 #endif /* CONFIG_WPS_NFC */
   1021 
   1022 	wps->state = SEND_M3;
   1023 	return WPS_CONTINUE;
   1024 }
   1025 
   1026 
   1027 static enum wps_process_res wps_process_m2d(struct wps_data *wps,
   1028 					    struct wps_parse_attr *attr)
   1029 {
   1030 	wpa_printf(MSG_DEBUG, "WPS: Received M2D");
   1031 
   1032 	if (wps->state != RECV_M2) {
   1033 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
   1034 			   "receiving M2D", wps->state);
   1035 		wps->state = SEND_WSC_NACK;
   1036 		return WPS_CONTINUE;
   1037 	}
   1038 
   1039 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Manufacturer",
   1040 			  attr->manufacturer, attr->manufacturer_len);
   1041 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Name",
   1042 			  attr->model_name, attr->model_name_len);
   1043 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Number",
   1044 			  attr->model_number, attr->model_number_len);
   1045 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Serial Number",
   1046 			  attr->serial_number, attr->serial_number_len);
   1047 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Device Name",
   1048 			  attr->dev_name, attr->dev_name_len);
   1049 
   1050 	if (wps->wps->event_cb) {
   1051 		union wps_event_data data;
   1052 		struct wps_event_m2d *m2d = &data.m2d;
   1053 		os_memset(&data, 0, sizeof(data));
   1054 		if (attr->config_methods)
   1055 			m2d->config_methods =
   1056 				WPA_GET_BE16(attr->config_methods);
   1057 		m2d->manufacturer = attr->manufacturer;
   1058 		m2d->manufacturer_len = attr->manufacturer_len;
   1059 		m2d->model_name = attr->model_name;
   1060 		m2d->model_name_len = attr->model_name_len;
   1061 		m2d->model_number = attr->model_number;
   1062 		m2d->model_number_len = attr->model_number_len;
   1063 		m2d->serial_number = attr->serial_number;
   1064 		m2d->serial_number_len = attr->serial_number_len;
   1065 		m2d->dev_name = attr->dev_name;
   1066 		m2d->dev_name_len = attr->dev_name_len;
   1067 		m2d->primary_dev_type = attr->primary_dev_type;
   1068 		if (attr->config_error)
   1069 			m2d->config_error =
   1070 				WPA_GET_BE16(attr->config_error);
   1071 		if (attr->dev_password_id)
   1072 			m2d->dev_password_id =
   1073 				WPA_GET_BE16(attr->dev_password_id);
   1074 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_M2D, &data);
   1075 	}
   1076 
   1077 	wps->state = RECEIVED_M2D;
   1078 	return WPS_CONTINUE;
   1079 }
   1080 
   1081 
   1082 static enum wps_process_res wps_process_m4(struct wps_data *wps,
   1083 					   const struct wpabuf *msg,
   1084 					   struct wps_parse_attr *attr)
   1085 {
   1086 	struct wpabuf *decrypted;
   1087 	struct wps_parse_attr eattr;
   1088 
   1089 	wpa_printf(MSG_DEBUG, "WPS: Received M4");
   1090 
   1091 	if (wps->state != RECV_M4) {
   1092 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
   1093 			   "receiving M4", wps->state);
   1094 		wps->state = SEND_WSC_NACK;
   1095 		return WPS_CONTINUE;
   1096 	}
   1097 
   1098 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
   1099 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
   1100 	    wps_process_r_hash1(wps, attr->r_hash1) ||
   1101 	    wps_process_r_hash2(wps, attr->r_hash2)) {
   1102 		wps->state = SEND_WSC_NACK;
   1103 		return WPS_CONTINUE;
   1104 	}
   1105 
   1106 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
   1107 					      attr->encr_settings_len);
   1108 	if (decrypted == NULL) {
   1109 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
   1110 			   "Settings attribute");
   1111 		wps->state = SEND_WSC_NACK;
   1112 		return WPS_CONTINUE;
   1113 	}
   1114 
   1115 	if (wps_validate_m4_encr(decrypted, attr->version2 != NULL) < 0) {
   1116 		wpabuf_clear_free(decrypted);
   1117 		wps->state = SEND_WSC_NACK;
   1118 		return WPS_CONTINUE;
   1119 	}
   1120 
   1121 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
   1122 		   "attribute");
   1123 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
   1124 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
   1125 	    wps_process_r_snonce1(wps, eattr.r_snonce1)) {
   1126 		wpabuf_clear_free(decrypted);
   1127 		wps->state = SEND_WSC_NACK;
   1128 		return WPS_CONTINUE;
   1129 	}
   1130 	wpabuf_clear_free(decrypted);
   1131 
   1132 	wps->state = SEND_M5;
   1133 	return WPS_CONTINUE;
   1134 }
   1135 
   1136 
   1137 static enum wps_process_res wps_process_m6(struct wps_data *wps,
   1138 					   const struct wpabuf *msg,
   1139 					   struct wps_parse_attr *attr)
   1140 {
   1141 	struct wpabuf *decrypted;
   1142 	struct wps_parse_attr eattr;
   1143 
   1144 	wpa_printf(MSG_DEBUG, "WPS: Received M6");
   1145 
   1146 	if (wps->state != RECV_M6) {
   1147 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
   1148 			   "receiving M6", wps->state);
   1149 		wps->state = SEND_WSC_NACK;
   1150 		return WPS_CONTINUE;
   1151 	}
   1152 
   1153 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
   1154 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
   1155 		wps->state = SEND_WSC_NACK;
   1156 		return WPS_CONTINUE;
   1157 	}
   1158 
   1159 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
   1160 					      attr->encr_settings_len);
   1161 	if (decrypted == NULL) {
   1162 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
   1163 			   "Settings attribute");
   1164 		wps->state = SEND_WSC_NACK;
   1165 		return WPS_CONTINUE;
   1166 	}
   1167 
   1168 	if (wps_validate_m6_encr(decrypted, attr->version2 != NULL) < 0) {
   1169 		wpabuf_clear_free(decrypted);
   1170 		wps->state = SEND_WSC_NACK;
   1171 		return WPS_CONTINUE;
   1172 	}
   1173 
   1174 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
   1175 		   "attribute");
   1176 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
   1177 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
   1178 	    wps_process_r_snonce2(wps, eattr.r_snonce2)) {
   1179 		wpabuf_clear_free(decrypted);
   1180 		wps->state = SEND_WSC_NACK;
   1181 		return WPS_CONTINUE;
   1182 	}
   1183 	wpabuf_clear_free(decrypted);
   1184 
   1185 	if (wps->wps->ap)
   1186 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_AP_PIN_SUCCESS,
   1187 				   NULL);
   1188 
   1189 	wps->state = SEND_M7;
   1190 	return WPS_CONTINUE;
   1191 }
   1192 
   1193 
   1194 static enum wps_process_res wps_process_m8(struct wps_data *wps,
   1195 					   const struct wpabuf *msg,
   1196 					   struct wps_parse_attr *attr)
   1197 {
   1198 	struct wpabuf *decrypted;
   1199 	struct wps_parse_attr eattr;
   1200 
   1201 	wpa_printf(MSG_DEBUG, "WPS: Received M8");
   1202 
   1203 	if (wps->state != RECV_M8) {
   1204 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
   1205 			   "receiving M8", wps->state);
   1206 		wps->state = SEND_WSC_NACK;
   1207 		return WPS_CONTINUE;
   1208 	}
   1209 
   1210 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
   1211 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
   1212 		wps->state = SEND_WSC_NACK;
   1213 		return WPS_CONTINUE;
   1214 	}
   1215 
   1216 	if (wps->wps->ap && wps->wps->ap_setup_locked) {
   1217 		/*
   1218 		 * Stop here if special ap_setup_locked == 2 mode allowed the
   1219 		 * protocol to continue beyond M2. This allows ER to learn the
   1220 		 * current AP settings without changing them.
   1221 		 */
   1222 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
   1223 			   "registration of a new Registrar");
   1224 		wps->config_error = WPS_CFG_SETUP_LOCKED;
   1225 		wps->state = SEND_WSC_NACK;
   1226 		return WPS_CONTINUE;
   1227 	}
   1228 
   1229 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
   1230 					      attr->encr_settings_len);
   1231 	if (decrypted == NULL) {
   1232 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
   1233 			   "Settings attribute");
   1234 		wps->state = SEND_WSC_NACK;
   1235 		return WPS_CONTINUE;
   1236 	}
   1237 
   1238 	if (wps_validate_m8_encr(decrypted, wps->wps->ap,
   1239 				 attr->version2 != NULL) < 0) {
   1240 		wpabuf_clear_free(decrypted);
   1241 		wps->state = SEND_WSC_NACK;
   1242 		return WPS_CONTINUE;
   1243 	}
   1244 
   1245 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
   1246 		   "attribute");
   1247 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
   1248 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
   1249 	    wps_process_creds(wps, eattr.cred, eattr.cred_len,
   1250 			      eattr.num_cred, attr->version2 != NULL) ||
   1251 	    wps_process_ap_settings_e(wps, &eattr, decrypted,
   1252 				      attr->version2 != NULL)) {
   1253 		wpabuf_clear_free(decrypted);
   1254 		wps->state = SEND_WSC_NACK;
   1255 		return WPS_CONTINUE;
   1256 	}
   1257 	wpabuf_clear_free(decrypted);
   1258 
   1259 	wps->state = WPS_MSG_DONE;
   1260 	return WPS_CONTINUE;
   1261 }
   1262 
   1263 
   1264 static enum wps_process_res wps_process_wsc_msg(struct wps_data *wps,
   1265 						const struct wpabuf *msg)
   1266 {
   1267 	struct wps_parse_attr attr;
   1268 	enum wps_process_res ret = WPS_CONTINUE;
   1269 
   1270 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_MSG");
   1271 
   1272 	if (wps_parse_msg(msg, &attr) < 0)
   1273 		return WPS_FAILURE;
   1274 
   1275 	if (attr.enrollee_nonce == NULL ||
   1276 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
   1277 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
   1278 		return WPS_FAILURE;
   1279 	}
   1280 
   1281 	if (attr.msg_type == NULL) {
   1282 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
   1283 		wps->state = SEND_WSC_NACK;
   1284 		return WPS_CONTINUE;
   1285 	}
   1286 
   1287 	switch (*attr.msg_type) {
   1288 	case WPS_M2:
   1289 		if (wps_validate_m2(msg) < 0)
   1290 			return WPS_FAILURE;
   1291 		ret = wps_process_m2(wps, msg, &attr);
   1292 		break;
   1293 	case WPS_M2D:
   1294 		if (wps_validate_m2d(msg) < 0)
   1295 			return WPS_FAILURE;
   1296 		ret = wps_process_m2d(wps, &attr);
   1297 		break;
   1298 	case WPS_M4:
   1299 		if (wps_validate_m4(msg) < 0)
   1300 			return WPS_FAILURE;
   1301 		ret = wps_process_m4(wps, msg, &attr);
   1302 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
   1303 			wps_fail_event(wps->wps, WPS_M4, wps->config_error,
   1304 				       wps->error_indication,
   1305 				       wps->peer_dev.mac_addr);
   1306 		break;
   1307 	case WPS_M6:
   1308 		if (wps_validate_m6(msg) < 0)
   1309 			return WPS_FAILURE;
   1310 		ret = wps_process_m6(wps, msg, &attr);
   1311 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
   1312 			wps_fail_event(wps->wps, WPS_M6, wps->config_error,
   1313 				       wps->error_indication,
   1314 				       wps->peer_dev.mac_addr);
   1315 		break;
   1316 	case WPS_M8:
   1317 		if (wps_validate_m8(msg) < 0)
   1318 			return WPS_FAILURE;
   1319 		ret = wps_process_m8(wps, msg, &attr);
   1320 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
   1321 			wps_fail_event(wps->wps, WPS_M8, wps->config_error,
   1322 				       wps->error_indication,
   1323 				       wps->peer_dev.mac_addr);
   1324 		break;
   1325 	default:
   1326 		wpa_printf(MSG_DEBUG, "WPS: Unsupported Message Type %d",
   1327 			   *attr.msg_type);
   1328 		return WPS_FAILURE;
   1329 	}
   1330 
   1331 	/*
   1332 	 * Save a copy of the last message for Authenticator derivation if we
   1333 	 * are continuing. However, skip M2D since it is not authenticated and
   1334 	 * neither is the ACK/NACK response frame. This allows the possibly
   1335 	 * following M2 to be processed correctly by using the previously sent
   1336 	 * M1 in Authenticator derivation.
   1337 	 */
   1338 	if (ret == WPS_CONTINUE && *attr.msg_type != WPS_M2D) {
   1339 		/* Save a copy of the last message for Authenticator derivation
   1340 		 */
   1341 		wpabuf_free(wps->last_msg);
   1342 		wps->last_msg = wpabuf_dup(msg);
   1343 	}
   1344 
   1345 	return ret;
   1346 }
   1347 
   1348 
   1349 static enum wps_process_res wps_process_wsc_ack(struct wps_data *wps,
   1350 						const struct wpabuf *msg)
   1351 {
   1352 	struct wps_parse_attr attr;
   1353 
   1354 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_ACK");
   1355 
   1356 	if (wps_parse_msg(msg, &attr) < 0)
   1357 		return WPS_FAILURE;
   1358 
   1359 	if (attr.msg_type == NULL) {
   1360 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
   1361 		return WPS_FAILURE;
   1362 	}
   1363 
   1364 	if (*attr.msg_type != WPS_WSC_ACK) {
   1365 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
   1366 			   *attr.msg_type);
   1367 		return WPS_FAILURE;
   1368 	}
   1369 
   1370 	if (attr.registrar_nonce == NULL ||
   1371 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
   1372 	{
   1373 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
   1374 		return WPS_FAILURE;
   1375 	}
   1376 
   1377 	if (attr.enrollee_nonce == NULL ||
   1378 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
   1379 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
   1380 		return WPS_FAILURE;
   1381 	}
   1382 
   1383 	if (wps->state == RECV_ACK && wps->wps->ap) {
   1384 		wpa_printf(MSG_DEBUG, "WPS: External Registrar registration "
   1385 			   "completed successfully");
   1386 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
   1387 		wps->state = WPS_FINISHED;
   1388 		return WPS_DONE;
   1389 	}
   1390 
   1391 	return WPS_FAILURE;
   1392 }
   1393 
   1394 
   1395 static enum wps_process_res wps_process_wsc_nack(struct wps_data *wps,
   1396 						 const struct wpabuf *msg)
   1397 {
   1398 	struct wps_parse_attr attr;
   1399 	u16 config_error;
   1400 
   1401 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_NACK");
   1402 
   1403 	if (wps_parse_msg(msg, &attr) < 0)
   1404 		return WPS_FAILURE;
   1405 
   1406 	if (attr.msg_type == NULL) {
   1407 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
   1408 		return WPS_FAILURE;
   1409 	}
   1410 
   1411 	if (*attr.msg_type != WPS_WSC_NACK) {
   1412 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
   1413 			   *attr.msg_type);
   1414 		return WPS_FAILURE;
   1415 	}
   1416 
   1417 	if (attr.registrar_nonce == NULL ||
   1418 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
   1419 	{
   1420 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
   1421 		wpa_hexdump(MSG_DEBUG, "WPS: Received Registrar Nonce",
   1422 			    attr.registrar_nonce, WPS_NONCE_LEN);
   1423 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Registrar Nonce",
   1424 			    wps->nonce_r, WPS_NONCE_LEN);
   1425 		return WPS_FAILURE;
   1426 	}
   1427 
   1428 	if (attr.enrollee_nonce == NULL ||
   1429 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
   1430 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
   1431 		wpa_hexdump(MSG_DEBUG, "WPS: Received Enrollee Nonce",
   1432 			    attr.enrollee_nonce, WPS_NONCE_LEN);
   1433 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Enrollee Nonce",
   1434 			    wps->nonce_e, WPS_NONCE_LEN);
   1435 		return WPS_FAILURE;
   1436 	}
   1437 
   1438 	if (attr.config_error == NULL) {
   1439 		wpa_printf(MSG_DEBUG, "WPS: No Configuration Error attribute "
   1440 			   "in WSC_NACK");
   1441 		return WPS_FAILURE;
   1442 	}
   1443 
   1444 	config_error = WPA_GET_BE16(attr.config_error);
   1445 	wpa_printf(MSG_DEBUG, "WPS: Registrar terminated negotiation with "
   1446 		   "Configuration Error %d", config_error);
   1447 
   1448 	switch (wps->state) {
   1449 	case RECV_M4:
   1450 		wps_fail_event(wps->wps, WPS_M3, config_error,
   1451 			       wps->error_indication, wps->peer_dev.mac_addr);
   1452 		break;
   1453 	case RECV_M6:
   1454 		wps_fail_event(wps->wps, WPS_M5, config_error,
   1455 			       wps->error_indication, wps->peer_dev.mac_addr);
   1456 		break;
   1457 	case RECV_M8:
   1458 		wps_fail_event(wps->wps, WPS_M7, config_error,
   1459 			       wps->error_indication, wps->peer_dev.mac_addr);
   1460 		break;
   1461 	default:
   1462 		break;
   1463 	}
   1464 
   1465 	/* Followed by NACK if Enrollee is Supplicant or EAP-Failure if
   1466 	 * Enrollee is Authenticator */
   1467 	wps->state = SEND_WSC_NACK;
   1468 
   1469 	return WPS_FAILURE;
   1470 }
   1471 
   1472 
   1473 enum wps_process_res wps_enrollee_process_msg(struct wps_data *wps,
   1474 					      enum wsc_op_code op_code,
   1475 					      const struct wpabuf *msg)
   1476 {
   1477 
   1478 	wpa_printf(MSG_DEBUG, "WPS: Processing received message (len=%lu "
   1479 		   "op_code=%d)",
   1480 		   (unsigned long) wpabuf_len(msg), op_code);
   1481 
   1482 	if (op_code == WSC_UPnP) {
   1483 		/* Determine the OpCode based on message type attribute */
   1484 		struct wps_parse_attr attr;
   1485 		if (wps_parse_msg(msg, &attr) == 0 && attr.msg_type) {
   1486 			if (*attr.msg_type == WPS_WSC_ACK)
   1487 				op_code = WSC_ACK;
   1488 			else if (*attr.msg_type == WPS_WSC_NACK)
   1489 				op_code = WSC_NACK;
   1490 		}
   1491 	}
   1492 
   1493 	switch (op_code) {
   1494 	case WSC_MSG:
   1495 	case WSC_UPnP:
   1496 		return wps_process_wsc_msg(wps, msg);
   1497 	case WSC_ACK:
   1498 		if (wps_validate_wsc_ack(msg) < 0)
   1499 			return WPS_FAILURE;
   1500 		return wps_process_wsc_ack(wps, msg);
   1501 	case WSC_NACK:
   1502 		if (wps_validate_wsc_nack(msg) < 0)
   1503 			return WPS_FAILURE;
   1504 		return wps_process_wsc_nack(wps, msg);
   1505 	default:
   1506 		wpa_printf(MSG_DEBUG, "WPS: Unsupported op_code %d", op_code);
   1507 		return WPS_FAILURE;
   1508 	}
   1509 }
   1510