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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_clear_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_clear_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 int 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 	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd,
138 			(dev_passwd_len + 1) / 2, hash) < 0)
139 		return -1;
140 	os_memcpy(wps->psk1, hash, WPS_PSK_LEN);
141 	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN,
142 			dev_passwd + (dev_passwd_len + 1) / 2,
143 			dev_passwd_len / 2, hash) < 0)
144 		return -1;
145 	os_memcpy(wps->psk2, hash, WPS_PSK_LEN);
146 
147 	wpa_hexdump_ascii_key(MSG_DEBUG, "WPS: Device Password",
148 			      dev_passwd, dev_passwd_len);
149 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK1", wps->psk1, WPS_PSK_LEN);
150 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK2", wps->psk2, WPS_PSK_LEN);
151 	return 0;
152 }
153 
154 
wps_decrypt_encr_settings(struct wps_data * wps,const u8 * encr,size_t encr_len)155 struct wpabuf * wps_decrypt_encr_settings(struct wps_data *wps, const u8 *encr,
156 					  size_t encr_len)
157 {
158 	struct wpabuf *decrypted;
159 	const size_t block_size = 16;
160 	size_t i;
161 	u8 pad;
162 	const u8 *pos;
163 
164 	/* AES-128-CBC */
165 	if (encr == NULL || encr_len < 2 * block_size || encr_len % block_size)
166 	{
167 		wpa_printf(MSG_DEBUG, "WPS: No Encrypted Settings received");
168 		return NULL;
169 	}
170 
171 	decrypted = wpabuf_alloc(encr_len - block_size);
172 	if (decrypted == NULL)
173 		return NULL;
174 
175 	wpa_hexdump(MSG_MSGDUMP, "WPS: Encrypted Settings", encr, encr_len);
176 	wpabuf_put_data(decrypted, encr + block_size, encr_len - block_size);
177 	if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted),
178 				wpabuf_len(decrypted))) {
179 		wpabuf_clear_free(decrypted);
180 		return NULL;
181 	}
182 
183 	wpa_hexdump_buf_key(MSG_MSGDUMP, "WPS: Decrypted Encrypted Settings",
184 			    decrypted);
185 
186 	pos = wpabuf_head_u8(decrypted) + wpabuf_len(decrypted) - 1;
187 	pad = *pos;
188 	if (pad > wpabuf_len(decrypted)) {
189 		wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad value");
190 		wpabuf_clear_free(decrypted);
191 		return NULL;
192 	}
193 	for (i = 0; i < pad; i++) {
194 		if (*pos-- != pad) {
195 			wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad "
196 				   "string");
197 			wpabuf_clear_free(decrypted);
198 			return NULL;
199 		}
200 	}
201 	decrypted->used -= pad;
202 
203 	return decrypted;
204 }
205 
206 
207 /**
208  * wps_pin_checksum - Compute PIN checksum
209  * @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
210  * Returns: Checksum digit
211  */
wps_pin_checksum(unsigned int pin)212 unsigned int wps_pin_checksum(unsigned int pin)
213 {
214 	unsigned int accum = 0;
215 	while (pin) {
216 		accum += 3 * (pin % 10);
217 		pin /= 10;
218 		accum += pin % 10;
219 		pin /= 10;
220 	}
221 
222 	return (10 - accum % 10) % 10;
223 }
224 
225 
226 /**
227  * wps_pin_valid - Check whether a PIN has a valid checksum
228  * @pin: Eight digit PIN (i.e., including the checksum digit)
229  * Returns: 1 if checksum digit is valid, or 0 if not
230  */
wps_pin_valid(unsigned int pin)231 unsigned int wps_pin_valid(unsigned int pin)
232 {
233 	return wps_pin_checksum(pin / 10) == (pin % 10);
234 }
235 
236 
237 /**
238  * wps_generate_pin - Generate a random PIN
239  * Returns: Eight digit PIN (i.e., including the checksum digit)
240  */
wps_generate_pin(unsigned int * pin)241 int wps_generate_pin(unsigned int *pin)
242 {
243 	unsigned int val;
244 
245 	/* Generate seven random digits for the PIN */
246 	if (random_get_bytes((unsigned char *) &val, sizeof(val)) < 0)
247 		return -1;
248 	val %= 10000000;
249 
250 	/* Append checksum digit */
251 	*pin = val * 10 + wps_pin_checksum(val);
252 	return 0;
253 }
254 
255 
wps_pin_str_valid(const char * pin)256 int wps_pin_str_valid(const char *pin)
257 {
258 	const char *p;
259 	size_t len;
260 
261 	p = pin;
262 	while (*p >= '0' && *p <= '9')
263 		p++;
264 	if (*p != '\0')
265 		return 0;
266 
267 	len = p - pin;
268 	return len == 4 || len == 8;
269 }
270 
271 
wps_fail_event(struct wps_context * wps,enum wps_msg_type msg,u16 config_error,u16 error_indication,const u8 * mac_addr)272 void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg,
273 		    u16 config_error, u16 error_indication, const u8 *mac_addr)
274 {
275 	union wps_event_data data;
276 
277 	if (wps->event_cb == NULL)
278 		return;
279 
280 	os_memset(&data, 0, sizeof(data));
281 	data.fail.msg = msg;
282 	data.fail.config_error = config_error;
283 	data.fail.error_indication = error_indication;
284 	os_memcpy(data.fail.peer_macaddr, mac_addr, ETH_ALEN);
285 	wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, &data);
286 }
287 
288 
wps_success_event(struct wps_context * wps,const u8 * mac_addr)289 void wps_success_event(struct wps_context *wps, const u8 *mac_addr)
290 {
291 	union wps_event_data data;
292 
293 	if (wps->event_cb == NULL)
294 		return;
295 
296 	os_memset(&data, 0, sizeof(data));
297 	os_memcpy(data.success.peer_macaddr, mac_addr, ETH_ALEN);
298 	wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, &data);
299 }
300 
301 
wps_pwd_auth_fail_event(struct wps_context * wps,int enrollee,int part,const u8 * mac_addr)302 void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part,
303 			     const u8 *mac_addr)
304 {
305 	union wps_event_data data;
306 
307 	if (wps->event_cb == NULL)
308 		return;
309 
310 	os_memset(&data, 0, sizeof(data));
311 	data.pwd_auth_fail.enrollee = enrollee;
312 	data.pwd_auth_fail.part = part;
313 	os_memcpy(data.pwd_auth_fail.peer_macaddr, mac_addr, ETH_ALEN);
314 	wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, &data);
315 }
316 
317 
wps_pbc_overlap_event(struct wps_context * wps)318 void wps_pbc_overlap_event(struct wps_context *wps)
319 {
320 	if (wps->event_cb == NULL)
321 		return;
322 
323 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_OVERLAP, NULL);
324 }
325 
326 
wps_pbc_timeout_event(struct wps_context * wps)327 void wps_pbc_timeout_event(struct wps_context *wps)
328 {
329 	if (wps->event_cb == NULL)
330 		return;
331 
332 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_TIMEOUT, NULL);
333 }
334 
335 
wps_pbc_active_event(struct wps_context * wps)336 void wps_pbc_active_event(struct wps_context *wps)
337 {
338 	if (wps->event_cb == NULL)
339 		return;
340 
341 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_ACTIVE, NULL);
342 }
343 
344 
wps_pbc_disable_event(struct wps_context * wps)345 void wps_pbc_disable_event(struct wps_context *wps)
346 {
347 	if (wps->event_cb == NULL)
348 		return;
349 
350 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_DISABLE, NULL);
351 }
352 
353 
354 #ifdef CONFIG_WPS_OOB
355 
wps_get_oob_cred(struct wps_context * wps,int rf_band,int channel)356 struct wpabuf * wps_get_oob_cred(struct wps_context *wps, int rf_band,
357 				 int channel)
358 {
359 	struct wps_data data;
360 	struct wpabuf *plain;
361 
362 	plain = wpabuf_alloc(500);
363 	if (plain == NULL) {
364 		wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB "
365 			   "credential");
366 		return NULL;
367 	}
368 
369 	os_memset(&data, 0, sizeof(data));
370 	data.wps = wps;
371 	data.auth_type = wps->auth_types;
372 	data.encr_type = wps->encr_types;
373 	if (wps_build_cred(&data, plain) ||
374 	    (rf_band && wps_build_rf_bands_attr(plain, rf_band)) ||
375 	    (channel && wps_build_ap_channel(plain, channel)) ||
376 	    wps_build_mac_addr(plain, wps->dev.mac_addr) ||
377 	    wps_build_wfa_ext(plain, 0, NULL, 0)) {
378 		os_free(data.new_psk);
379 		wpabuf_clear_free(plain);
380 		return NULL;
381 	}
382 
383 	if (wps->wps_state == WPS_STATE_NOT_CONFIGURED && data.new_psk &&
384 	    wps->ap) {
385 		struct wps_credential cred;
386 
387 		wpa_printf(MSG_DEBUG, "WPS: Moving to Configured state based "
388 			   "on credential token generation");
389 
390 		os_memset(&cred, 0, sizeof(cred));
391 		os_memcpy(cred.ssid, wps->ssid, wps->ssid_len);
392 		cred.ssid_len = wps->ssid_len;
393 		cred.auth_type = WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK;
394 		cred.encr_type = WPS_ENCR_TKIP | WPS_ENCR_AES;
395 		os_memcpy(cred.key, data.new_psk, data.new_psk_len);
396 		cred.key_len = data.new_psk_len;
397 
398 		wps->wps_state = WPS_STATE_CONFIGURED;
399 		wpa_hexdump_ascii_key(MSG_DEBUG,
400 				      "WPS: Generated random passphrase",
401 				      data.new_psk, data.new_psk_len);
402 		if (wps->cred_cb)
403 			wps->cred_cb(wps->cb_ctx, &cred);
404 	}
405 
406 	os_free(data.new_psk);
407 
408 	return plain;
409 }
410 
411 
wps_build_nfc_pw_token(u16 dev_pw_id,const struct wpabuf * pubkey,const struct wpabuf * dev_pw)412 struct wpabuf * wps_build_nfc_pw_token(u16 dev_pw_id,
413 				       const struct wpabuf *pubkey,
414 				       const struct wpabuf *dev_pw)
415 {
416 	struct wpabuf *data;
417 
418 	data = wpabuf_alloc(200);
419 	if (data == NULL)
420 		return NULL;
421 
422 	if (wps_build_oob_dev_pw(data, dev_pw_id, pubkey,
423 				 wpabuf_head(dev_pw), wpabuf_len(dev_pw)) ||
424 	    wps_build_wfa_ext(data, 0, NULL, 0)) {
425 		wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password "
426 			   "token");
427 		wpabuf_clear_free(data);
428 		return NULL;
429 	}
430 
431 	return data;
432 }
433 
434 
wps_oob_use_cred(struct wps_context * wps,struct wps_parse_attr * attr)435 int wps_oob_use_cred(struct wps_context *wps, struct wps_parse_attr *attr)
436 {
437 	struct wpabuf msg;
438 	size_t i;
439 
440 	for (i = 0; i < attr->num_cred; i++) {
441 		struct wps_credential local_cred;
442 		struct wps_parse_attr cattr;
443 
444 		os_memset(&local_cred, 0, sizeof(local_cred));
445 		wpabuf_set(&msg, attr->cred[i], attr->cred_len[i]);
446 		if (wps_parse_msg(&msg, &cattr) < 0 ||
447 		    wps_process_cred(&cattr, &local_cred)) {
448 			wpa_printf(MSG_ERROR, "WPS: Failed to parse OOB "
449 				   "credential");
450 			return -1;
451 		}
452 		wps->cred_cb(wps->cb_ctx, &local_cred);
453 	}
454 
455 	return 0;
456 }
457 
458 
459 #endif /* CONFIG_WPS_OOB */
460 
461 
wps_dev_type_str2bin(const char * str,u8 dev_type[WPS_DEV_TYPE_LEN])462 int wps_dev_type_str2bin(const char *str, u8 dev_type[WPS_DEV_TYPE_LEN])
463 {
464 	const char *pos;
465 
466 	/* <categ>-<OUI>-<subcateg> */
467 	WPA_PUT_BE16(dev_type, atoi(str));
468 	pos = os_strchr(str, '-');
469 	if (pos == NULL)
470 		return -1;
471 	pos++;
472 	if (hexstr2bin(pos, &dev_type[2], 4))
473 		return -1;
474 	pos = os_strchr(pos, '-');
475 	if (pos == NULL)
476 		return -1;
477 	pos++;
478 	WPA_PUT_BE16(&dev_type[6], atoi(pos));
479 
480 
481 	return 0;
482 }
483 
484 
wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN],char * buf,size_t buf_len)485 char * wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN], char *buf,
486 			    size_t buf_len)
487 {
488 	int ret;
489 
490 	ret = os_snprintf(buf, buf_len, "%u-%08X-%u",
491 			  WPA_GET_BE16(dev_type), WPA_GET_BE32(&dev_type[2]),
492 			  WPA_GET_BE16(&dev_type[6]));
493 	if (os_snprintf_error(buf_len, ret))
494 		return NULL;
495 
496 	return buf;
497 }
498 
499 
uuid_gen_mac_addr(const u8 * mac_addr,u8 * uuid)500 void uuid_gen_mac_addr(const u8 *mac_addr, u8 *uuid)
501 {
502 	const u8 *addr[2];
503 	size_t len[2];
504 	u8 hash[SHA1_MAC_LEN];
505 	u8 nsid[16] = {
506 		0x52, 0x64, 0x80, 0xf8,
507 		0xc9, 0x9b,
508 		0x4b, 0xe5,
509 		0xa6, 0x55,
510 		0x58, 0xed, 0x5f, 0x5d, 0x60, 0x84
511 	};
512 
513 	addr[0] = nsid;
514 	len[0] = sizeof(nsid);
515 	addr[1] = mac_addr;
516 	len[1] = 6;
517 	sha1_vector(2, addr, len, hash);
518 	os_memcpy(uuid, hash, 16);
519 
520 	/* Version: 5 = named-based version using SHA-1 */
521 	uuid[6] = (5 << 4) | (uuid[6] & 0x0f);
522 
523 	/* Variant specified in RFC 4122 */
524 	uuid[8] = 0x80 | (uuid[8] & 0x3f);
525 }
526 
527 
wps_config_methods_str2bin(const char * str)528 u16 wps_config_methods_str2bin(const char *str)
529 {
530 	u16 methods = 0;
531 
532 	if (str == NULL || str[0] == '\0') {
533 		/* Default to enabling methods based on build configuration */
534 		methods |= WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD;
535 		methods |= WPS_CONFIG_VIRT_DISPLAY;
536 #ifdef CONFIG_WPS_NFC
537 		methods |= WPS_CONFIG_NFC_INTERFACE;
538 #endif /* CONFIG_WPS_NFC */
539 #ifdef CONFIG_P2P
540 		methods |= WPS_CONFIG_P2PS;
541 #endif /* CONFIG_P2P */
542 	} else {
543 		if (os_strstr(str, "ethernet"))
544 			methods |= WPS_CONFIG_ETHERNET;
545 		if (os_strstr(str, "label"))
546 			methods |= WPS_CONFIG_LABEL;
547 		if (os_strstr(str, "display"))
548 			methods |= WPS_CONFIG_DISPLAY;
549 		if (os_strstr(str, "ext_nfc_token"))
550 			methods |= WPS_CONFIG_EXT_NFC_TOKEN;
551 		if (os_strstr(str, "int_nfc_token"))
552 			methods |= WPS_CONFIG_INT_NFC_TOKEN;
553 		if (os_strstr(str, "nfc_interface"))
554 			methods |= WPS_CONFIG_NFC_INTERFACE;
555 		if (os_strstr(str, "push_button"))
556 			methods |= WPS_CONFIG_PUSHBUTTON;
557 		if (os_strstr(str, "keypad"))
558 			methods |= WPS_CONFIG_KEYPAD;
559 		if (os_strstr(str, "virtual_display"))
560 			methods |= WPS_CONFIG_VIRT_DISPLAY;
561 		if (os_strstr(str, "physical_display"))
562 			methods |= WPS_CONFIG_PHY_DISPLAY;
563 		if (os_strstr(str, "virtual_push_button"))
564 			methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
565 		if (os_strstr(str, "physical_push_button"))
566 			methods |= WPS_CONFIG_PHY_PUSHBUTTON;
567 		if (os_strstr(str, "p2ps"))
568 			methods |= WPS_CONFIG_P2PS;
569 	}
570 
571 	return methods;
572 }
573 
574 
wps_build_wsc_ack(struct wps_data * wps)575 struct wpabuf * wps_build_wsc_ack(struct wps_data *wps)
576 {
577 	struct wpabuf *msg;
578 
579 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_ACK");
580 
581 	msg = wpabuf_alloc(1000);
582 	if (msg == NULL)
583 		return NULL;
584 
585 	if (wps_build_version(msg) ||
586 	    wps_build_msg_type(msg, WPS_WSC_ACK) ||
587 	    wps_build_enrollee_nonce(wps, msg) ||
588 	    wps_build_registrar_nonce(wps, msg) ||
589 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
590 		wpabuf_free(msg);
591 		return NULL;
592 	}
593 
594 	return msg;
595 }
596 
597 
wps_build_wsc_nack(struct wps_data * wps)598 struct wpabuf * wps_build_wsc_nack(struct wps_data *wps)
599 {
600 	struct wpabuf *msg;
601 
602 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_NACK");
603 
604 	msg = wpabuf_alloc(1000);
605 	if (msg == NULL)
606 		return NULL;
607 
608 	if (wps_build_version(msg) ||
609 	    wps_build_msg_type(msg, WPS_WSC_NACK) ||
610 	    wps_build_enrollee_nonce(wps, msg) ||
611 	    wps_build_registrar_nonce(wps, msg) ||
612 	    wps_build_config_error(msg, wps->config_error) ||
613 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
614 		wpabuf_free(msg);
615 		return NULL;
616 	}
617 
618 	return msg;
619 }
620 
621 
622 #ifdef CONFIG_WPS_NFC
623 
wps_nfc_token_build(int ndef,int id,struct wpabuf * pubkey,struct wpabuf * dev_pw)624 struct wpabuf * wps_nfc_token_build(int ndef, int id, struct wpabuf *pubkey,
625 				    struct wpabuf *dev_pw)
626 {
627 	struct wpabuf *ret;
628 
629 	if (pubkey == NULL || dev_pw == NULL)
630 		return NULL;
631 
632 	ret = wps_build_nfc_pw_token(id, pubkey, dev_pw);
633 	if (ndef && ret) {
634 		struct wpabuf *tmp;
635 		tmp = ndef_build_wifi(ret);
636 		wpabuf_free(ret);
637 		if (tmp == NULL)
638 			return NULL;
639 		ret = tmp;
640 	}
641 
642 	return ret;
643 }
644 
645 
wps_nfc_gen_dh(struct wpabuf ** pubkey,struct wpabuf ** privkey)646 int wps_nfc_gen_dh(struct wpabuf **pubkey, struct wpabuf **privkey)
647 {
648 	struct wpabuf *priv = NULL, *pub = NULL;
649 	void *dh_ctx;
650 
651 	dh_ctx = dh5_init(&priv, &pub);
652 	if (dh_ctx == NULL)
653 		return -1;
654 	pub = wpabuf_zeropad(pub, 192);
655 	if (pub == NULL) {
656 		wpabuf_free(priv);
657 		return -1;
658 	}
659 	wpa_hexdump_buf(MSG_DEBUG, "WPS: Generated new DH pubkey", pub);
660 	dh5_free(dh_ctx);
661 
662 	wpabuf_free(*pubkey);
663 	*pubkey = pub;
664 	wpabuf_clear_free(*privkey);
665 	*privkey = priv;
666 
667 	return 0;
668 }
669 
670 
wps_nfc_token_gen(int ndef,int * id,struct wpabuf ** pubkey,struct wpabuf ** privkey,struct wpabuf ** dev_pw)671 struct wpabuf * wps_nfc_token_gen(int ndef, int *id, struct wpabuf **pubkey,
672 				  struct wpabuf **privkey,
673 				  struct wpabuf **dev_pw)
674 {
675 	struct wpabuf *pw;
676 	u16 val;
677 
678 	pw = wpabuf_alloc(WPS_OOB_DEVICE_PASSWORD_LEN);
679 	if (pw == NULL)
680 		return NULL;
681 
682 	if (random_get_bytes(wpabuf_put(pw, WPS_OOB_DEVICE_PASSWORD_LEN),
683 			     WPS_OOB_DEVICE_PASSWORD_LEN) ||
684 	    random_get_bytes((u8 *) &val, sizeof(val))) {
685 		wpabuf_free(pw);
686 		return NULL;
687 	}
688 
689 	if (wps_nfc_gen_dh(pubkey, privkey) < 0) {
690 		wpabuf_free(pw);
691 		return NULL;
692 	}
693 
694 	*id = 0x10 + val % 0xfff0;
695 	wpabuf_clear_free(*dev_pw);
696 	*dev_pw = pw;
697 
698 	return wps_nfc_token_build(ndef, *id, *pubkey, *dev_pw);
699 }
700 
701 
wps_build_nfc_handover_req(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey)702 struct wpabuf * wps_build_nfc_handover_req(struct wps_context *ctx,
703 					   struct wpabuf *nfc_dh_pubkey)
704 {
705 	struct wpabuf *msg;
706 	void *len;
707 
708 	if (ctx == NULL)
709 		return NULL;
710 
711 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
712 		   "handover request");
713 
714 	if (nfc_dh_pubkey == NULL) {
715 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
716 			   "configured");
717 		return NULL;
718 	}
719 
720 	msg = wpabuf_alloc(1000);
721 	if (msg == NULL)
722 		return msg;
723 	len = wpabuf_put(msg, 2);
724 
725 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
726 				 nfc_dh_pubkey, NULL, 0) ||
727 	    wps_build_uuid_e(msg, ctx->uuid) ||
728 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
729 		wpabuf_free(msg);
730 		return NULL;
731 	}
732 
733 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
734 
735 	return msg;
736 }
737 
738 
wps_build_ssid(struct wpabuf * msg,struct wps_context * wps)739 static int wps_build_ssid(struct wpabuf *msg, struct wps_context *wps)
740 {
741 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
742 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID in Connection Handover Select",
743 			  wps->ssid, wps->ssid_len);
744 	wpabuf_put_be16(msg, ATTR_SSID);
745 	wpabuf_put_be16(msg, wps->ssid_len);
746 	wpabuf_put_data(msg, wps->ssid, wps->ssid_len);
747 	return 0;
748 }
749 
750 
wps_build_ap_freq(struct wpabuf * msg,int freq)751 static int wps_build_ap_freq(struct wpabuf *msg, int freq)
752 {
753 	enum hostapd_hw_mode mode;
754 	u8 channel, rf_band;
755 	u16 ap_channel;
756 
757 	if (freq <= 0)
758 		return 0;
759 
760 	mode = ieee80211_freq_to_chan(freq, &channel);
761 	if (mode == NUM_HOSTAPD_MODES)
762 		return 0; /* Unknown channel */
763 
764 	if (mode == HOSTAPD_MODE_IEEE80211G || mode == HOSTAPD_MODE_IEEE80211B)
765 		rf_band = WPS_RF_24GHZ;
766 	else if (mode == HOSTAPD_MODE_IEEE80211A)
767 		rf_band = WPS_RF_50GHZ;
768 	else if (mode == HOSTAPD_MODE_IEEE80211AD)
769 		rf_band = WPS_RF_60GHZ;
770 	else
771 		return 0; /* Unknown band */
772 	ap_channel = channel;
773 
774 	if (wps_build_rf_bands_attr(msg, rf_band) ||
775 	    wps_build_ap_channel(msg, ap_channel))
776 		return -1;
777 
778 	return 0;
779 }
780 
781 
wps_build_nfc_handover_sel(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey,const u8 * bssid,int freq)782 struct wpabuf * wps_build_nfc_handover_sel(struct wps_context *ctx,
783 					   struct wpabuf *nfc_dh_pubkey,
784 					   const u8 *bssid, int freq)
785 {
786 	struct wpabuf *msg;
787 	void *len;
788 
789 	if (ctx == NULL)
790 		return NULL;
791 
792 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
793 		   "handover select");
794 
795 	if (nfc_dh_pubkey == NULL) {
796 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
797 			   "configured");
798 		return NULL;
799 	}
800 
801 	msg = wpabuf_alloc(1000);
802 	if (msg == NULL)
803 		return msg;
804 	len = wpabuf_put(msg, 2);
805 
806 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
807 				 nfc_dh_pubkey, NULL, 0) ||
808 	    wps_build_ssid(msg, ctx) ||
809 	    wps_build_ap_freq(msg, freq) ||
810 	    (bssid && wps_build_mac_addr(msg, bssid)) ||
811 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
812 		wpabuf_free(msg);
813 		return NULL;
814 	}
815 
816 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);
817 
818 	return msg;
819 }
820 
821 
wps_build_nfc_handover_req_p2p(struct wps_context * ctx,struct wpabuf * nfc_dh_pubkey)822 struct wpabuf * wps_build_nfc_handover_req_p2p(struct wps_context *ctx,
823 					       struct wpabuf *nfc_dh_pubkey)
824 {
825 	struct wpabuf *msg;
826 
827 	if (ctx == NULL)
828 		return NULL;
829 
830 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
831 		   "handover request (P2P)");
832 
833 	if (nfc_dh_pubkey == NULL) {
834 		wpa_printf(MSG_DEBUG, "WPS: No NFC DH Public Key configured");
835 		return NULL;
836 	}
837 
838 	msg = wpabuf_alloc(1000);
839 	if (msg == NULL)
840 		return msg;
841 
842 	if (wps_build_manufacturer(&ctx->dev, msg) ||
843 	    wps_build_model_name(&ctx->dev, msg) ||
844 	    wps_build_model_number(&ctx->dev, msg) ||
845 	    wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
846 				 nfc_dh_pubkey, NULL, 0) ||
847 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
848 	    wps_build_serial_number(&ctx->dev, msg) ||
849 	    wps_build_uuid_e(msg, ctx->uuid) ||
850 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
851 		wpabuf_free(msg);
852 		return NULL;
853 	}
854 
855 	return msg;
856 }
857 
858 
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)859 struct wpabuf * wps_build_nfc_handover_sel_p2p(struct wps_context *ctx,
860 					       int nfc_dev_pw_id,
861 					       struct wpabuf *nfc_dh_pubkey,
862 					       struct wpabuf *nfc_dev_pw)
863 {
864 	struct wpabuf *msg;
865 	const u8 *dev_pw;
866 	size_t dev_pw_len;
867 
868 	if (ctx == NULL)
869 		return NULL;
870 
871 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
872 		   "handover select (P2P)");
873 
874 	if (nfc_dh_pubkey == NULL ||
875 	    (nfc_dev_pw_id != DEV_PW_NFC_CONNECTION_HANDOVER &&
876 	     nfc_dev_pw == NULL)) {
877 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
878 			   "configured");
879 		return NULL;
880 	}
881 
882 	msg = wpabuf_alloc(1000);
883 	if (msg == NULL)
884 		return msg;
885 
886 	if (nfc_dev_pw) {
887 		dev_pw = wpabuf_head(nfc_dev_pw);
888 		dev_pw_len = wpabuf_len(nfc_dev_pw);
889 	} else {
890 		dev_pw = NULL;
891 		dev_pw_len = 0;
892 	}
893 
894 	if (wps_build_manufacturer(&ctx->dev, msg) ||
895 	    wps_build_model_name(&ctx->dev, msg) ||
896 	    wps_build_model_number(&ctx->dev, msg) ||
897 	    wps_build_oob_dev_pw(msg, nfc_dev_pw_id, nfc_dh_pubkey,
898 				 dev_pw, dev_pw_len) ||
899 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
900 	    wps_build_serial_number(&ctx->dev, msg) ||
901 	    wps_build_uuid_e(msg, ctx->uuid) ||
902 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
903 		wpabuf_free(msg);
904 		return NULL;
905 	}
906 
907 	return msg;
908 }
909 
910 #endif /* CONFIG_WPS_NFC */
911