xref: /freebsd/contrib/wpa/src/wps/wps_common.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*
2  * Wi-Fi Protected Setup - common functionality
3  * Copyright (c) 2008-2012, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "common/defs.h"
13 #include "common/ieee802_11_common.h"
14 #include "crypto/aes_wrap.h"
15 #include "crypto/crypto.h"
16 #include "crypto/dh_group5.h"
17 #include "crypto/sha1.h"
18 #include "crypto/sha256.h"
19 #include "crypto/random.h"
20 #include "wps_i.h"
21 #include "wps_dev_attr.h"
22 
23 
24 void wps_kdf(const u8 *key, const u8 *label_prefix, size_t label_prefix_len,
25 	     const char *label, u8 *res, size_t res_len)
26 {
27 	u8 i_buf[4], key_bits[4];
28 	const u8 *addr[4];
29 	size_t len[4];
30 	int i, iter;
31 	u8 hash[SHA256_MAC_LEN], *opos;
32 	size_t left;
33 
34 	WPA_PUT_BE32(key_bits, res_len * 8);
35 
36 	addr[0] = i_buf;
37 	len[0] = sizeof(i_buf);
38 	addr[1] = label_prefix;
39 	len[1] = label_prefix_len;
40 	addr[2] = (const u8 *) label;
41 	len[2] = os_strlen(label);
42 	addr[3] = key_bits;
43 	len[3] = sizeof(key_bits);
44 
45 	iter = (res_len + SHA256_MAC_LEN - 1) / SHA256_MAC_LEN;
46 	opos = res;
47 	left = res_len;
48 
49 	for (i = 1; i <= iter; i++) {
50 		WPA_PUT_BE32(i_buf, i);
51 		hmac_sha256_vector(key, SHA256_MAC_LEN, 4, addr, len, hash);
52 		if (i < iter) {
53 			os_memcpy(opos, hash, SHA256_MAC_LEN);
54 			opos += SHA256_MAC_LEN;
55 			left -= SHA256_MAC_LEN;
56 		} else
57 			os_memcpy(opos, hash, left);
58 	}
59 }
60 
61 
62 int wps_derive_keys(struct wps_data *wps)
63 {
64 	struct wpabuf *pubkey, *dh_shared;
65 	u8 dhkey[SHA256_MAC_LEN], kdk[SHA256_MAC_LEN];
66 	const u8 *addr[3];
67 	size_t len[3];
68 	u8 keys[WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN + WPS_EMSK_LEN];
69 
70 	if (wps->dh_privkey == NULL) {
71 		wpa_printf(MSG_DEBUG, "WPS: Own DH private key not available");
72 		return -1;
73 	}
74 
75 	pubkey = wps->registrar ? wps->dh_pubkey_e : wps->dh_pubkey_r;
76 	if (pubkey == NULL) {
77 		wpa_printf(MSG_DEBUG, "WPS: Peer DH public key not available");
78 		return -1;
79 	}
80 
81 	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
82 	wpa_hexdump_buf(MSG_DEBUG, "WPS: DH peer Public Key", pubkey);
83 	dh_shared = dh5_derive_shared(wps->dh_ctx, pubkey, wps->dh_privkey);
84 	dh5_free(wps->dh_ctx);
85 	wps->dh_ctx = NULL;
86 	dh_shared = wpabuf_zeropad(dh_shared, 192);
87 	if (dh_shared == NULL) {
88 		wpa_printf(MSG_DEBUG, "WPS: Failed to derive DH shared key");
89 		return -1;
90 	}
91 
92 	/* Own DH private key is not needed anymore */
93 	wpabuf_free(wps->dh_privkey);
94 	wps->dh_privkey = NULL;
95 
96 	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH shared key", dh_shared);
97 
98 	/* DHKey = SHA-256(g^AB mod p) */
99 	addr[0] = wpabuf_head(dh_shared);
100 	len[0] = wpabuf_len(dh_shared);
101 	sha256_vector(1, addr, len, dhkey);
102 	wpa_hexdump_key(MSG_DEBUG, "WPS: DHKey", dhkey, sizeof(dhkey));
103 	wpabuf_free(dh_shared);
104 
105 	/* KDK = HMAC-SHA-256_DHKey(N1 || EnrolleeMAC || N2) */
106 	addr[0] = wps->nonce_e;
107 	len[0] = WPS_NONCE_LEN;
108 	addr[1] = wps->mac_addr_e;
109 	len[1] = ETH_ALEN;
110 	addr[2] = wps->nonce_r;
111 	len[2] = WPS_NONCE_LEN;
112 	hmac_sha256_vector(dhkey, sizeof(dhkey), 3, addr, len, kdk);
113 	wpa_hexdump_key(MSG_DEBUG, "WPS: KDK", kdk, sizeof(kdk));
114 
115 	wps_kdf(kdk, NULL, 0, "Wi-Fi Easy and Secure Key Derivation",
116 		keys, sizeof(keys));
117 	os_memcpy(wps->authkey, keys, WPS_AUTHKEY_LEN);
118 	os_memcpy(wps->keywrapkey, keys + WPS_AUTHKEY_LEN, WPS_KEYWRAPKEY_LEN);
119 	os_memcpy(wps->emsk, keys + WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN,
120 		  WPS_EMSK_LEN);
121 
122 	wpa_hexdump_key(MSG_DEBUG, "WPS: AuthKey",
123 			wps->authkey, WPS_AUTHKEY_LEN);
124 	wpa_hexdump_key(MSG_DEBUG, "WPS: KeyWrapKey",
125 			wps->keywrapkey, WPS_KEYWRAPKEY_LEN);
126 	wpa_hexdump_key(MSG_DEBUG, "WPS: EMSK", wps->emsk, WPS_EMSK_LEN);
127 
128 	return 0;
129 }
130 
131 
132 void wps_derive_psk(struct wps_data *wps, const u8 *dev_passwd,
133 		    size_t dev_passwd_len)
134 {
135 	u8 hash[SHA256_MAC_LEN];
136 
137 	hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd,
138 		    (dev_passwd_len + 1) / 2, hash);
139 	os_memcpy(wps->psk1, hash, WPS_PSK_LEN);
140 	hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN,
141 		    dev_passwd + (dev_passwd_len + 1) / 2,
142 		    dev_passwd_len / 2, hash);
143 	os_memcpy(wps->psk2, hash, WPS_PSK_LEN);
144 
145 	wpa_hexdump_ascii_key(MSG_DEBUG, "WPS: Device Password",
146 			      dev_passwd, dev_passwd_len);
147 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK1", wps->psk1, WPS_PSK_LEN);
148 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK2", wps->psk2, WPS_PSK_LEN);
149 }
150 
151 
152 struct wpabuf * wps_decrypt_encr_settings(struct wps_data *wps, const u8 *encr,
153 					  size_t encr_len)
154 {
155 	struct wpabuf *decrypted;
156 	const size_t block_size = 16;
157 	size_t i;
158 	u8 pad;
159 	const u8 *pos;
160 
161 	/* AES-128-CBC */
162 	if (encr == NULL || encr_len < 2 * block_size || encr_len % block_size)
163 	{
164 		wpa_printf(MSG_DEBUG, "WPS: No Encrypted Settings received");
165 		return NULL;
166 	}
167 
168 	decrypted = wpabuf_alloc(encr_len - block_size);
169 	if (decrypted == NULL)
170 		return NULL;
171 
172 	wpa_hexdump(MSG_MSGDUMP, "WPS: Encrypted Settings", encr, encr_len);
173 	wpabuf_put_data(decrypted, encr + block_size, encr_len - block_size);
174 	if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted),
175 				wpabuf_len(decrypted))) {
176 		wpabuf_free(decrypted);
177 		return NULL;
178 	}
179 
180 	wpa_hexdump_buf_key(MSG_MSGDUMP, "WPS: Decrypted Encrypted Settings",
181 			    decrypted);
182 
183 	pos = wpabuf_head_u8(decrypted) + wpabuf_len(decrypted) - 1;
184 	pad = *pos;
185 	if (pad > wpabuf_len(decrypted)) {
186 		wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad value");
187 		wpabuf_free(decrypted);
188 		return NULL;
189 	}
190 	for (i = 0; i < pad; i++) {
191 		if (*pos-- != pad) {
192 			wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad "
193 				   "string");
194 			wpabuf_free(decrypted);
195 			return NULL;
196 		}
197 	}
198 	decrypted->used -= pad;
199 
200 	return decrypted;
201 }
202 
203 
204 /**
205  * wps_pin_checksum - Compute PIN checksum
206  * @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
207  * Returns: Checksum digit
208  */
209 unsigned int wps_pin_checksum(unsigned int pin)
210 {
211 	unsigned int accum = 0;
212 	while (pin) {
213 		accum += 3 * (pin % 10);
214 		pin /= 10;
215 		accum += pin % 10;
216 		pin /= 10;
217 	}
218 
219 	return (10 - accum % 10) % 10;
220 }
221 
222 
223 /**
224  * wps_pin_valid - Check whether a PIN has a valid checksum
225  * @pin: Eight digit PIN (i.e., including the checksum digit)
226  * Returns: 1 if checksum digit is valid, or 0 if not
227  */
228 unsigned int wps_pin_valid(unsigned int pin)
229 {
230 	return wps_pin_checksum(pin / 10) == (pin % 10);
231 }
232 
233 
234 /**
235  * wps_generate_pin - Generate a random PIN
236  * Returns: Eight digit PIN (i.e., including the checksum digit)
237  */
238 unsigned int wps_generate_pin(void)
239 {
240 	unsigned int val;
241 
242 	/* Generate seven random digits for the PIN */
243 	if (random_get_bytes((unsigned char *) &val, sizeof(val)) < 0) {
244 		struct os_time now;
245 		os_get_time(&now);
246 		val = os_random() ^ now.sec ^ now.usec;
247 	}
248 	val %= 10000000;
249 
250 	/* Append checksum digit */
251 	return val * 10 + wps_pin_checksum(val);
252 }
253 
254 
255 int wps_pin_str_valid(const char *pin)
256 {
257 	const char *p;
258 	size_t len;
259 
260 	p = pin;
261 	while (*p >= '0' && *p <= '9')
262 		p++;
263 	if (*p != '\0')
264 		return 0;
265 
266 	len = p - pin;
267 	return len == 4 || len == 8;
268 }
269 
270 
271 void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg,
272 		    u16 config_error, u16 error_indication, const u8 *mac_addr)
273 {
274 	union wps_event_data data;
275 
276 	if (wps->event_cb == NULL)
277 		return;
278 
279 	os_memset(&data, 0, sizeof(data));
280 	data.fail.msg = msg;
281 	data.fail.config_error = config_error;
282 	data.fail.error_indication = error_indication;
283 	os_memcpy(data.fail.peer_macaddr, mac_addr, ETH_ALEN);
284 	wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, &data);
285 }
286 
287 
288 void wps_success_event(struct wps_context *wps, const u8 *mac_addr)
289 {
290 	union wps_event_data data;
291 
292 	if (wps->event_cb == NULL)
293 		return;
294 
295 	os_memset(&data, 0, sizeof(data));
296 	os_memcpy(data.success.peer_macaddr, mac_addr, ETH_ALEN);
297 	wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, &data);
298 }
299 
300 
301 void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part,
302 			     const u8 *mac_addr)
303 {
304 	union wps_event_data data;
305 
306 	if (wps->event_cb == NULL)
307 		return;
308 
309 	os_memset(&data, 0, sizeof(data));
310 	data.pwd_auth_fail.enrollee = enrollee;
311 	data.pwd_auth_fail.part = part;
312 	os_memcpy(data.pwd_auth_fail.peer_macaddr, mac_addr, ETH_ALEN);
313 	wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, &data);
314 }
315 
316 
317 void wps_pbc_overlap_event(struct wps_context *wps)
318 {
319 	if (wps->event_cb == NULL)
320 		return;
321 
322 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_OVERLAP, NULL);
323 }
324 
325 
326 void wps_pbc_timeout_event(struct wps_context *wps)
327 {
328 	if (wps->event_cb == NULL)
329 		return;
330 
331 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_TIMEOUT, NULL);
332 }
333 
334 
335 void wps_pbc_active_event(struct wps_context *wps)
336 {
337 	if (wps->event_cb == NULL)
338 		return;
339 
340 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_ACTIVE, NULL);
341 }
342 
343 
344 void wps_pbc_disable_event(struct wps_context *wps)
345 {
346 	if (wps->event_cb == NULL)
347 		return;
348 
349 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_DISABLE, NULL);
350 }
351 
352 
353 #ifdef CONFIG_WPS_OOB
354 
355 struct wpabuf * wps_get_oob_cred(struct wps_context *wps, 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 
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 
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 
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 
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 (os_snprintf_error(buf_len, ret))
493 		return NULL;
494 
495 	return buf;
496 }
497 
498 
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 
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 #ifdef CONFIG_P2P
539 		methods |= WPS_CONFIG_P2PS;
540 #endif /* CONFIG_P2P */
541 	} else {
542 		if (os_strstr(str, "ethernet"))
543 			methods |= WPS_CONFIG_ETHERNET;
544 		if (os_strstr(str, "label"))
545 			methods |= WPS_CONFIG_LABEL;
546 		if (os_strstr(str, "display"))
547 			methods |= WPS_CONFIG_DISPLAY;
548 		if (os_strstr(str, "ext_nfc_token"))
549 			methods |= WPS_CONFIG_EXT_NFC_TOKEN;
550 		if (os_strstr(str, "int_nfc_token"))
551 			methods |= WPS_CONFIG_INT_NFC_TOKEN;
552 		if (os_strstr(str, "nfc_interface"))
553 			methods |= WPS_CONFIG_NFC_INTERFACE;
554 		if (os_strstr(str, "push_button"))
555 			methods |= WPS_CONFIG_PUSHBUTTON;
556 		if (os_strstr(str, "keypad"))
557 			methods |= WPS_CONFIG_KEYPAD;
558 		if (os_strstr(str, "virtual_display"))
559 			methods |= WPS_CONFIG_VIRT_DISPLAY;
560 		if (os_strstr(str, "physical_display"))
561 			methods |= WPS_CONFIG_PHY_DISPLAY;
562 		if (os_strstr(str, "virtual_push_button"))
563 			methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
564 		if (os_strstr(str, "physical_push_button"))
565 			methods |= WPS_CONFIG_PHY_PUSHBUTTON;
566 		if (os_strstr(str, "p2ps"))
567 			methods |= WPS_CONFIG_P2PS;
568 	}
569 
570 	return methods;
571 }
572 
573 
574 struct wpabuf * wps_build_wsc_ack(struct wps_data *wps)
575 {
576 	struct wpabuf *msg;
577 
578 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_ACK");
579 
580 	msg = wpabuf_alloc(1000);
581 	if (msg == NULL)
582 		return NULL;
583 
584 	if (wps_build_version(msg) ||
585 	    wps_build_msg_type(msg, WPS_WSC_ACK) ||
586 	    wps_build_enrollee_nonce(wps, msg) ||
587 	    wps_build_registrar_nonce(wps, msg) ||
588 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
589 		wpabuf_free(msg);
590 		return NULL;
591 	}
592 
593 	return msg;
594 }
595 
596 
597 struct wpabuf * wps_build_wsc_nack(struct wps_data *wps)
598 {
599 	struct wpabuf *msg;
600 
601 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_NACK");
602 
603 	msg = wpabuf_alloc(1000);
604 	if (msg == NULL)
605 		return NULL;
606 
607 	if (wps_build_version(msg) ||
608 	    wps_build_msg_type(msg, WPS_WSC_NACK) ||
609 	    wps_build_enrollee_nonce(wps, msg) ||
610 	    wps_build_registrar_nonce(wps, msg) ||
611 	    wps_build_config_error(msg, wps->config_error) ||
612 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
613 		wpabuf_free(msg);
614 		return NULL;
615 	}
616 
617 	return msg;
618 }
619 
620 
621 #ifdef CONFIG_WPS_NFC
622 
623 struct wpabuf * wps_nfc_token_build(int ndef, int id, struct wpabuf *pubkey,
624 				    struct wpabuf *dev_pw)
625 {
626 	struct wpabuf *ret;
627 
628 	if (pubkey == NULL || dev_pw == NULL)
629 		return NULL;
630 
631 	ret = wps_build_nfc_pw_token(id, pubkey, dev_pw);
632 	if (ndef && ret) {
633 		struct wpabuf *tmp;
634 		tmp = ndef_build_wifi(ret);
635 		wpabuf_free(ret);
636 		if (tmp == NULL)
637 			return NULL;
638 		ret = tmp;
639 	}
640 
641 	return ret;
642 }
643 
644 
645 int wps_nfc_gen_dh(struct wpabuf **pubkey, struct wpabuf **privkey)
646 {
647 	struct wpabuf *priv = NULL, *pub = NULL;
648 	void *dh_ctx;
649 
650 	dh_ctx = dh5_init(&priv, &pub);
651 	if (dh_ctx == NULL)
652 		return -1;
653 	pub = wpabuf_zeropad(pub, 192);
654 	if (pub == NULL) {
655 		wpabuf_free(priv);
656 		return -1;
657 	}
658 	wpa_hexdump_buf(MSG_DEBUG, "WPS: Generated new DH pubkey", pub);
659 	dh5_free(dh_ctx);
660 
661 	wpabuf_free(*pubkey);
662 	*pubkey = pub;
663 	wpabuf_free(*privkey);
664 	*privkey = priv;
665 
666 	return 0;
667 }
668 
669 
670 struct wpabuf * wps_nfc_token_gen(int ndef, int *id, struct wpabuf **pubkey,
671 				  struct wpabuf **privkey,
672 				  struct wpabuf **dev_pw)
673 {
674 	struct wpabuf *pw;
675 	u16 val;
676 
677 	pw = wpabuf_alloc(WPS_OOB_DEVICE_PASSWORD_LEN);
678 	if (pw == NULL)
679 		return NULL;
680 
681 	if (random_get_bytes(wpabuf_put(pw, WPS_OOB_DEVICE_PASSWORD_LEN),
682 			     WPS_OOB_DEVICE_PASSWORD_LEN) ||
683 	    random_get_bytes((u8 *) &val, sizeof(val))) {
684 		wpabuf_free(pw);
685 		return NULL;
686 	}
687 
688 	if (wps_nfc_gen_dh(pubkey, privkey) < 0) {
689 		wpabuf_free(pw);
690 		return NULL;
691 	}
692 
693 	*id = 0x10 + val % 0xfff0;
694 	wpabuf_free(*dev_pw);
695 	*dev_pw = pw;
696 
697 	return wps_nfc_token_build(ndef, *id, *pubkey, *dev_pw);
698 }
699 
700 
701 struct wpabuf * wps_build_nfc_handover_req(struct wps_context *ctx,
702 					   struct wpabuf *nfc_dh_pubkey)
703 {
704 	struct wpabuf *msg;
705 	void *len;
706 
707 	if (ctx == NULL)
708 		return NULL;
709 
710 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
711 		   "handover request");
712 
713 	if (nfc_dh_pubkey == NULL) {
714 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
715 			   "configured");
716 		return NULL;
717 	}
718 
719 	msg = wpabuf_alloc(1000);
720 	if (msg == NULL)
721 		return msg;
722 	len = wpabuf_put(msg, 2);
723 
724 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
725 				 nfc_dh_pubkey, NULL, 0) ||
726 	    wps_build_uuid_e(msg, ctx->uuid) ||
727 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
728 		wpabuf_free(msg);
729 		return NULL;
730 	}
731 
732 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
733 
734 	return msg;
735 }
736 
737 
738 static int wps_build_ssid(struct wpabuf *msg, struct wps_context *wps)
739 {
740 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
741 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID in Connection Handover Select",
742 			  wps->ssid, wps->ssid_len);
743 	wpabuf_put_be16(msg, ATTR_SSID);
744 	wpabuf_put_be16(msg, wps->ssid_len);
745 	wpabuf_put_data(msg, wps->ssid, wps->ssid_len);
746 	return 0;
747 }
748 
749 
750 static int wps_build_ap_freq(struct wpabuf *msg, int freq)
751 {
752 	enum hostapd_hw_mode mode;
753 	u8 channel, rf_band;
754 	u16 ap_channel;
755 
756 	if (freq <= 0)
757 		return 0;
758 
759 	mode = ieee80211_freq_to_chan(freq, &channel);
760 	if (mode == NUM_HOSTAPD_MODES)
761 		return 0; /* Unknown channel */
762 
763 	if (mode == HOSTAPD_MODE_IEEE80211G || mode == HOSTAPD_MODE_IEEE80211B)
764 		rf_band = WPS_RF_24GHZ;
765 	else if (mode == HOSTAPD_MODE_IEEE80211A)
766 		rf_band = WPS_RF_50GHZ;
767 	else
768 		return 0; /* Unknown band */
769 	ap_channel = channel;
770 
771 	if (wps_build_rf_bands_attr(msg, rf_band) ||
772 	    wps_build_ap_channel(msg, ap_channel))
773 		return -1;
774 
775 	return 0;
776 }
777 
778 
779 struct wpabuf * wps_build_nfc_handover_sel(struct wps_context *ctx,
780 					   struct wpabuf *nfc_dh_pubkey,
781 					   const u8 *bssid, int freq)
782 {
783 	struct wpabuf *msg;
784 	void *len;
785 
786 	if (ctx == NULL)
787 		return NULL;
788 
789 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
790 		   "handover select");
791 
792 	if (nfc_dh_pubkey == NULL) {
793 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
794 			   "configured");
795 		return NULL;
796 	}
797 
798 	msg = wpabuf_alloc(1000);
799 	if (msg == NULL)
800 		return msg;
801 	len = wpabuf_put(msg, 2);
802 
803 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
804 				 nfc_dh_pubkey, NULL, 0) ||
805 	    wps_build_ssid(msg, ctx) ||
806 	    wps_build_ap_freq(msg, freq) ||
807 	    (bssid && wps_build_mac_addr(msg, bssid)) ||
808 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
809 		wpabuf_free(msg);
810 		return NULL;
811 	}
812 
813 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
814 
815 	return msg;
816 }
817 
818 
819 struct wpabuf * wps_build_nfc_handover_req_p2p(struct wps_context *ctx,
820 					       struct wpabuf *nfc_dh_pubkey)
821 {
822 	struct wpabuf *msg;
823 
824 	if (ctx == NULL)
825 		return NULL;
826 
827 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
828 		   "handover request (P2P)");
829 
830 	if (nfc_dh_pubkey == NULL) {
831 		wpa_printf(MSG_DEBUG, "WPS: No NFC DH Public Key configured");
832 		return NULL;
833 	}
834 
835 	msg = wpabuf_alloc(1000);
836 	if (msg == NULL)
837 		return msg;
838 
839 	if (wps_build_manufacturer(&ctx->dev, msg) ||
840 	    wps_build_model_name(&ctx->dev, msg) ||
841 	    wps_build_model_number(&ctx->dev, msg) ||
842 	    wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
843 				 nfc_dh_pubkey, NULL, 0) ||
844 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
845 	    wps_build_serial_number(&ctx->dev, msg) ||
846 	    wps_build_uuid_e(msg, ctx->uuid) ||
847 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
848 		wpabuf_free(msg);
849 		return NULL;
850 	}
851 
852 	return msg;
853 }
854 
855 
856 struct wpabuf * wps_build_nfc_handover_sel_p2p(struct wps_context *ctx,
857 					       int nfc_dev_pw_id,
858 					       struct wpabuf *nfc_dh_pubkey,
859 					       struct wpabuf *nfc_dev_pw)
860 {
861 	struct wpabuf *msg;
862 	const u8 *dev_pw;
863 	size_t dev_pw_len;
864 
865 	if (ctx == NULL)
866 		return NULL;
867 
868 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
869 		   "handover select (P2P)");
870 
871 	if (nfc_dh_pubkey == NULL ||
872 	    (nfc_dev_pw_id != DEV_PW_NFC_CONNECTION_HANDOVER &&
873 	     nfc_dev_pw == NULL)) {
874 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
875 			   "configured");
876 		return NULL;
877 	}
878 
879 	msg = wpabuf_alloc(1000);
880 	if (msg == NULL)
881 		return msg;
882 
883 	if (nfc_dev_pw) {
884 		dev_pw = wpabuf_head(nfc_dev_pw);
885 		dev_pw_len = wpabuf_len(nfc_dev_pw);
886 	} else {
887 		dev_pw = NULL;
888 		dev_pw_len = 0;
889 	}
890 
891 	if (wps_build_manufacturer(&ctx->dev, msg) ||
892 	    wps_build_model_name(&ctx->dev, msg) ||
893 	    wps_build_model_number(&ctx->dev, msg) ||
894 	    wps_build_oob_dev_pw(msg, nfc_dev_pw_id, nfc_dh_pubkey,
895 				 dev_pw, dev_pw_len) ||
896 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
897 	    wps_build_serial_number(&ctx->dev, msg) ||
898 	    wps_build_uuid_e(msg, ctx->uuid) ||
899 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
900 		wpabuf_free(msg);
901 		return NULL;
902 	}
903 
904 	return msg;
905 }
906 
907 #endif /* CONFIG_WPS_NFC */
908