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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 
wps_kdf(const u8 * key,const u8 * label_prefix,size_t label_prefix_len,const char * label,u8 * res,size_t res_len)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 
wps_derive_keys(struct wps_data * wps)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 
wps_derive_psk(struct wps_data * wps,const u8 * dev_passwd,size_t dev_passwd_len)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 
wps_decrypt_encr_settings(struct wps_data * wps,const u8 * encr,size_t encr_len)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  */
wps_pin_checksum(unsigned int pin)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  */
wps_pin_valid(unsigned int pin)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  */
wps_generate_pin(void)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 
wps_pin_str_valid(const char * pin)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 
wps_fail_event(struct wps_context * wps,enum wps_msg_type msg,u16 config_error,u16 error_indication,const u8 * mac_addr)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 
wps_success_event(struct wps_context * wps,const u8 * mac_addr)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 
wps_pwd_auth_fail_event(struct wps_context * wps,int enrollee,int part,const u8 * mac_addr)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 
wps_pbc_overlap_event(struct wps_context * wps)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 
wps_pbc_timeout_event(struct wps_context * wps)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 
wps_pbc_active_event(struct wps_context * wps)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 
wps_pbc_disable_event(struct wps_context * wps)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 
wps_get_oob_cred(struct wps_context * wps,int rf_band,int channel)355 struct wpabuf * wps_get_oob_cred(struct wps_context *wps, int rf_band,
356 				 int channel)
357 {
358 	struct wps_data data;
359 	struct wpabuf *plain;
360 
361 	plain = wpabuf_alloc(500);
362 	if (plain == NULL) {
363 		wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB "
364 			   "credential");
365 		return NULL;
366 	}
367 
368 	os_memset(&data, 0, sizeof(data));
369 	data.wps = wps;
370 	data.auth_type = wps->auth_types;
371 	data.encr_type = wps->encr_types;
372 	if (wps_build_cred(&data, plain) ||
373 	    (rf_band && wps_build_rf_bands_attr(plain, rf_band)) ||
374 	    (channel && wps_build_ap_channel(plain, channel)) ||
375 	    wps_build_mac_addr(plain, wps->dev.mac_addr) ||
376 	    wps_build_wfa_ext(plain, 0, NULL, 0)) {
377 		os_free(data.new_psk);
378 		wpabuf_free(plain);
379 		return NULL;
380 	}
381 
382 	if (wps->wps_state == WPS_STATE_NOT_CONFIGURED && data.new_psk &&
383 	    wps->ap) {
384 		struct wps_credential cred;
385 
386 		wpa_printf(MSG_DEBUG, "WPS: Moving to Configured state based "
387 			   "on credential token generation");
388 
389 		os_memset(&cred, 0, sizeof(cred));
390 		os_memcpy(cred.ssid, wps->ssid, wps->ssid_len);
391 		cred.ssid_len = wps->ssid_len;
392 		cred.auth_type = WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK;
393 		cred.encr_type = WPS_ENCR_TKIP | WPS_ENCR_AES;
394 		os_memcpy(cred.key, data.new_psk, data.new_psk_len);
395 		cred.key_len = data.new_psk_len;
396 
397 		wps->wps_state = WPS_STATE_CONFIGURED;
398 		wpa_hexdump_ascii_key(MSG_DEBUG,
399 				      "WPS: Generated random passphrase",
400 				      data.new_psk, data.new_psk_len);
401 		if (wps->cred_cb)
402 			wps->cred_cb(wps->cb_ctx, &cred);
403 	}
404 
405 	os_free(data.new_psk);
406 
407 	return plain;
408 }
409 
410 
wps_build_nfc_pw_token(u16 dev_pw_id,const struct wpabuf * pubkey,const struct wpabuf * dev_pw)411 struct wpabuf * wps_build_nfc_pw_token(u16 dev_pw_id,
412 				       const struct wpabuf *pubkey,
413 				       const struct wpabuf *dev_pw)
414 {
415 	struct wpabuf *data;
416 
417 	data = wpabuf_alloc(200);
418 	if (data == NULL)
419 		return NULL;
420 
421 	if (wps_build_oob_dev_pw(data, dev_pw_id, pubkey,
422 				 wpabuf_head(dev_pw), wpabuf_len(dev_pw)) ||
423 	    wps_build_wfa_ext(data, 0, NULL, 0)) {
424 		wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password "
425 			   "token");
426 		wpabuf_free(data);
427 		return NULL;
428 	}
429 
430 	return data;
431 }
432 
433 
wps_oob_use_cred(struct wps_context * wps,struct wps_parse_attr * attr)434 int wps_oob_use_cred(struct wps_context *wps, struct wps_parse_attr *attr)
435 {
436 	struct wpabuf msg;
437 	size_t i;
438 
439 	for (i = 0; i < attr->num_cred; i++) {
440 		struct wps_credential local_cred;
441 		struct wps_parse_attr cattr;
442 
443 		os_memset(&local_cred, 0, sizeof(local_cred));
444 		wpabuf_set(&msg, attr->cred[i], attr->cred_len[i]);
445 		if (wps_parse_msg(&msg, &cattr) < 0 ||
446 		    wps_process_cred(&cattr, &local_cred)) {
447 			wpa_printf(MSG_ERROR, "WPS: Failed to parse OOB "
448 				   "credential");
449 			return -1;
450 		}
451 		wps->cred_cb(wps->cb_ctx, &local_cred);
452 	}
453 
454 	return 0;
455 }
456 
457 
458 #endif /* CONFIG_WPS_OOB */
459 
460 
wps_dev_type_str2bin(const char * str,u8 dev_type[WPS_DEV_TYPE_LEN])461 int wps_dev_type_str2bin(const char *str, u8 dev_type[WPS_DEV_TYPE_LEN])
462 {
463 	const char *pos;
464 
465 	/* <categ>-<OUI>-<subcateg> */
466 	WPA_PUT_BE16(dev_type, atoi(str));
467 	pos = os_strchr(str, '-');
468 	if (pos == NULL)
469 		return -1;
470 	pos++;
471 	if (hexstr2bin(pos, &dev_type[2], 4))
472 		return -1;
473 	pos = os_strchr(pos, '-');
474 	if (pos == NULL)
475 		return -1;
476 	pos++;
477 	WPA_PUT_BE16(&dev_type[6], atoi(pos));
478 
479 
480 	return 0;
481 }
482 
483 
wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN],char * buf,size_t buf_len)484 char * wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN], char *buf,
485 			    size_t buf_len)
486 {
487 	int ret;
488 
489 	ret = os_snprintf(buf, buf_len, "%u-%08X-%u",
490 			  WPA_GET_BE16(dev_type), WPA_GET_BE32(&dev_type[2]),
491 			  WPA_GET_BE16(&dev_type[6]));
492 	if (ret < 0 || (unsigned int) ret >= buf_len)
493 		return NULL;
494 
495 	return buf;
496 }
497 
498 
uuid_gen_mac_addr(const u8 * mac_addr,u8 * uuid)499 void uuid_gen_mac_addr(const u8 *mac_addr, u8 *uuid)
500 {
501 	const u8 *addr[2];
502 	size_t len[2];
503 	u8 hash[SHA1_MAC_LEN];
504 	u8 nsid[16] = {
505 		0x52, 0x64, 0x80, 0xf8,
506 		0xc9, 0x9b,
507 		0x4b, 0xe5,
508 		0xa6, 0x55,
509 		0x58, 0xed, 0x5f, 0x5d, 0x60, 0x84
510 	};
511 
512 	addr[0] = nsid;
513 	len[0] = sizeof(nsid);
514 	addr[1] = mac_addr;
515 	len[1] = 6;
516 	sha1_vector(2, addr, len, hash);
517 	os_memcpy(uuid, hash, 16);
518 
519 	/* Version: 5 = named-based version using SHA-1 */
520 	uuid[6] = (5 << 4) | (uuid[6] & 0x0f);
521 
522 	/* Variant specified in RFC 4122 */
523 	uuid[8] = 0x80 | (uuid[8] & 0x3f);
524 }
525 
526 
wps_config_methods_str2bin(const char * str)527 u16 wps_config_methods_str2bin(const char *str)
528 {
529 	u16 methods = 0;
530 
531 	if (str == NULL) {
532 		/* Default to enabling methods based on build configuration */
533 		methods |= WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD;
534 		methods |= WPS_CONFIG_VIRT_DISPLAY;
535 #ifdef CONFIG_WPS_NFC
536 		methods |= WPS_CONFIG_NFC_INTERFACE;
537 #endif /* CONFIG_WPS_NFC */
538 	} else {
539 		if (os_strstr(str, "ethernet"))
540 			methods |= WPS_CONFIG_ETHERNET;
541 		if (os_strstr(str, "label"))
542 			methods |= WPS_CONFIG_LABEL;
543 		if (os_strstr(str, "display"))
544 			methods |= WPS_CONFIG_DISPLAY;
545 		if (os_strstr(str, "ext_nfc_token"))
546 			methods |= WPS_CONFIG_EXT_NFC_TOKEN;
547 		if (os_strstr(str, "int_nfc_token"))
548 			methods |= WPS_CONFIG_INT_NFC_TOKEN;
549 		if (os_strstr(str, "nfc_interface"))
550 			methods |= WPS_CONFIG_NFC_INTERFACE;
551 		if (os_strstr(str, "push_button"))
552 			methods |= WPS_CONFIG_PUSHBUTTON;
553 		if (os_strstr(str, "keypad"))
554 			methods |= WPS_CONFIG_KEYPAD;
555 		if (os_strstr(str, "virtual_display"))
556 			methods |= WPS_CONFIG_VIRT_DISPLAY;
557 		if (os_strstr(str, "physical_display"))
558 			methods |= WPS_CONFIG_PHY_DISPLAY;
559 		if (os_strstr(str, "virtual_push_button"))
560 			methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
561 		if (os_strstr(str, "physical_push_button"))
562 			methods |= WPS_CONFIG_PHY_PUSHBUTTON;
563 	}
564 
565 	return methods;
566 }
567 
568 
wps_build_wsc_ack(struct wps_data * wps)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 
wps_build_wsc_nack(struct wps_data * wps)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 
wps_nfc_token_build(int ndef,int id,struct wpabuf * pubkey,struct wpabuf * dev_pw)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 
wps_nfc_gen_dh(struct wpabuf ** pubkey,struct wpabuf ** privkey)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 
wps_nfc_token_gen(int ndef,int * id,struct wpabuf ** pubkey,struct wpabuf ** privkey,struct wpabuf ** dev_pw)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 
wps_build_nfc_handover_req(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey)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 
wps_build_ssid(struct wpabuf * msg,struct wps_context * wps)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 
wps_build_ap_freq(struct wpabuf * msg,int freq)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 
wps_build_nfc_handover_sel(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey,const u8 * bssid,int freq)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 
wps_build_nfc_handover_req_p2p(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey)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 
wps_build_nfc_handover_sel_p2p(struct wps_context * ctx,int nfc_dev_pw_id,struct wpabuf * nfc_dh_pubkey,struct wpabuf * nfc_dev_pw)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 */
903