src/wps/wps_common.c - LeafOS-Project/android_external_wpa_supplicant_8 - Gitiles

 /*
  * Wi-Fi Protected Setup - common functionality
  * Copyright (c) 2008-2012, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "includes.h"

 #include "common.h"
 #include "common/defs.h"
 #include "common/ieee802_11_common.h"
 #include "crypto/aes_wrap.h"
 #include "crypto/crypto.h"
 #include "crypto/dh_group5.h"
 #include "crypto/sha1.h"
 #include "crypto/sha256.h"
 #include "crypto/random.h"
 #include "wps_i.h"
 #include "wps_dev_attr.h"


 void wps_kdf(const u8 *key, const u8 *label_prefix, size_t label_prefix_len,
 	     const char *label, u8 *res, size_t res_len)
 {
 	u8 i_buf[4], key_bits[4];
 	const u8 *addr[4];
 	size_t len[4];
 	int i, iter;
 	u8 hash[SHA256_MAC_LEN], *opos;
 	size_t left;

 	WPA_PUT_BE32(key_bits, res_len * 8);

 	addr[0] = i_buf;
 	len[0] = sizeof(i_buf);
 	addr[1] = label_prefix;
 	len[1] = label_prefix_len;
 	addr[2] = (const u8 *) label;
 	len[2] = os_strlen(label);
 	addr[3] = key_bits;
 	len[3] = sizeof(key_bits);

 	iter = (res_len + SHA256_MAC_LEN - 1) / SHA256_MAC_LEN;
 	opos = res;
 	left = res_len;

 	for (i = 1; i <= iter; i++) {
 		WPA_PUT_BE32(i_buf, i);
 		hmac_sha256_vector(key, SHA256_MAC_LEN, 4, addr, len, hash);
 		if (i < iter) {
 			os_memcpy(opos, hash, SHA256_MAC_LEN);
 			opos += SHA256_MAC_LEN;
 			left -= SHA256_MAC_LEN;
 		} else
 			os_memcpy(opos, hash, left);
 	}
 }


 int wps_derive_keys(struct wps_data *wps)
 {
 	struct wpabuf *pubkey, *dh_shared;
 	u8 dhkey[SHA256_MAC_LEN], kdk[SHA256_MAC_LEN];
 	const u8 *addr[3];
 	size_t len[3];
 	u8 keys[WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN + WPS_EMSK_LEN];

 	if (wps->dh_privkey == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: Own DH private key not available");
 		return -1;
 	}

 	pubkey = wps->registrar ? wps->dh_pubkey_e : wps->dh_pubkey_r;
 	if (pubkey == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: Peer DH public key not available");
 		return -1;
 	}

 	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
 	wpa_hexdump_buf(MSG_DEBUG, "WPS: DH peer Public Key", pubkey);
 	dh_shared = dh5_derive_shared(wps->dh_ctx, pubkey, wps->dh_privkey);
 	dh5_free(wps->dh_ctx);
 	wps->dh_ctx = NULL;
 	dh_shared = wpabuf_zeropad(dh_shared, 192);
 	if (dh_shared == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: Failed to derive DH shared key");
 		return -1;
 	}

 	/* Own DH private key is not needed anymore */
 	wpabuf_clear_free(wps->dh_privkey);
 	wps->dh_privkey = NULL;

 	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH shared key", dh_shared);

 	/* DHKey = SHA-256(g^AB mod p) */
 	addr[0] = wpabuf_head(dh_shared);
 	len[0] = wpabuf_len(dh_shared);
 	sha256_vector(1, addr, len, dhkey);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: DHKey", dhkey, sizeof(dhkey));
 	wpabuf_clear_free(dh_shared);

 	/* KDK = HMAC-SHA-256_DHKey(N1 || EnrolleeMAC || N2) */
 	addr[0] = wps->nonce_e;
 	len[0] = WPS_NONCE_LEN;
 	addr[1] = wps->mac_addr_e;
 	len[1] = ETH_ALEN;
 	addr[2] = wps->nonce_r;
 	len[2] = WPS_NONCE_LEN;
 	hmac_sha256_vector(dhkey, sizeof(dhkey), 3, addr, len, kdk);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: KDK", kdk, sizeof(kdk));

 	wps_kdf(kdk, NULL, 0, "Wi-Fi Easy and Secure Key Derivation",
 		keys, sizeof(keys));
 	os_memcpy(wps->authkey, keys, WPS_AUTHKEY_LEN);
 	os_memcpy(wps->keywrapkey, keys + WPS_AUTHKEY_LEN, WPS_KEYWRAPKEY_LEN);
 	os_memcpy(wps->emsk, keys + WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN,
 		  WPS_EMSK_LEN);

 	wpa_hexdump_key(MSG_DEBUG, "WPS: AuthKey",
 			wps->authkey, WPS_AUTHKEY_LEN);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: KeyWrapKey",
 			wps->keywrapkey, WPS_KEYWRAPKEY_LEN);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: EMSK", wps->emsk, WPS_EMSK_LEN);

 	return 0;
 }


 int wps_derive_psk(struct wps_data *wps, const u8 *dev_passwd,
 		   size_t dev_passwd_len)
 {
 	u8 hash[SHA256_MAC_LEN];

 	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd,
 			(dev_passwd_len + 1) / 2, hash) < 0)
 		return -1;
 	os_memcpy(wps->psk1, hash, WPS_PSK_LEN);
 	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN,
 			dev_passwd + (dev_passwd_len + 1) / 2,
 			dev_passwd_len / 2, hash) < 0)
 		return -1;
 	os_memcpy(wps->psk2, hash, WPS_PSK_LEN);

 	wpa_hexdump_ascii_key(MSG_DEBUG, "WPS: Device Password",
 			      dev_passwd, dev_passwd_len);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK1", wps->psk1, WPS_PSK_LEN);
 	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK2", wps->psk2, WPS_PSK_LEN);
 	return 0;
 }


 struct wpabuf * wps_decrypt_encr_settings(struct wps_data *wps, const u8 *encr,
 					  size_t encr_len)
 {
 	struct wpabuf *decrypted;
 	const size_t block_size = 16;
 	size_t i;
 	u8 pad;
 	const u8 *pos;

 	/* AES-128-CBC */
 	if (encr == NULL || encr_len < 2 * block_size || encr_len % block_size)
 	{
 		wpa_printf(MSG_DEBUG, "WPS: No Encrypted Settings received");
 		return NULL;
 	}

 	decrypted = wpabuf_alloc(encr_len - block_size);
 	if (decrypted == NULL)
 		return NULL;

 	wpa_hexdump(MSG_MSGDUMP, "WPS: Encrypted Settings", encr, encr_len);
 	wpabuf_put_data(decrypted, encr + block_size, encr_len - block_size);
 	if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted),
 				wpabuf_len(decrypted))) {
 		wpabuf_clear_free(decrypted);
 		return NULL;
 	}

 	wpa_hexdump_buf_key(MSG_MSGDUMP, "WPS: Decrypted Encrypted Settings",
 			    decrypted);

 	pos = wpabuf_head_u8(decrypted) + wpabuf_len(decrypted) - 1;
 	pad = *pos;
 	if (pad > wpabuf_len(decrypted)) {
 		wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad value");
 		wpabuf_clear_free(decrypted);
 		return NULL;
 	}
 	for (i = 0; i < pad; i++) {
 		if (*pos-- != pad) {
 			wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad "
 				   "string");
 			wpabuf_clear_free(decrypted);
 			return NULL;
 		}
 	}
 	decrypted->used -= pad;

 	return decrypted;
 }


 /**
  * wps_pin_checksum - Compute PIN checksum
  * @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
  * Returns: Checksum digit
  */
 unsigned int wps_pin_checksum(unsigned int pin)
 {
 	unsigned int accum = 0;
 	while (pin) {
 		accum += 3 * (pin % 10);
 		pin /= 10;
 		accum += pin % 10;
 		pin /= 10;
 	}

 	return (10 - accum % 10) % 10;
 }


 /**
  * wps_pin_valid - Check whether a PIN has a valid checksum
  * @pin: Eight digit PIN (i.e., including the checksum digit)
  * Returns: 1 if checksum digit is valid, or 0 if not
  */
 unsigned int wps_pin_valid(unsigned int pin)
 {
 	return wps_pin_checksum(pin / 10) == (pin % 10);
 }


 /**
  * wps_generate_pin - Generate a random PIN
  * Returns: Eight digit PIN (i.e., including the checksum digit)
  */
 int wps_generate_pin(unsigned int *pin)
 {
 	unsigned int val;

 	/* Generate seven random digits for the PIN */
 	if (random_get_bytes((unsigned char *) &val, sizeof(val)) < 0)
 		return -1;
 	val %= 10000000;

 	/* Append checksum digit */
 	*pin = val * 10 + wps_pin_checksum(val);
 	return 0;
 }


 int wps_pin_str_valid(const char *pin)
 {
 	const char *p;
 	size_t len;

 	p = pin;
 	while (*p >= '0' && *p <= '9')
 		p++;
 	if (*p != '\0')
 		return 0;

 	len = p - pin;
 	return len == 4 || len == 8;
 }


 void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg,
 		    u16 config_error, u16 error_indication, const u8 *mac_addr)
 {
 	union wps_event_data data;

 	if (wps->event_cb == NULL)
 		return;

 	os_memset(&data, 0, sizeof(data));
 	data.fail.msg = msg;
 	data.fail.config_error = config_error;
 	data.fail.error_indication = error_indication;
 	os_memcpy(data.fail.peer_macaddr, mac_addr, ETH_ALEN);
 	wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, &data);
 }


 void wps_success_event(struct wps_context *wps, const u8 *mac_addr)
 {
 	union wps_event_data data;

 	if (wps->event_cb == NULL)
 		return;

 	os_memset(&data, 0, sizeof(data));
 	os_memcpy(data.success.peer_macaddr, mac_addr, ETH_ALEN);
 	wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, &data);
 }


 void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part,
 			     const u8 *mac_addr)
 {
 	union wps_event_data data;

 	if (wps->event_cb == NULL)
 		return;

 	os_memset(&data, 0, sizeof(data));
 	data.pwd_auth_fail.enrollee = enrollee;
 	data.pwd_auth_fail.part = part;
 	os_memcpy(data.pwd_auth_fail.peer_macaddr, mac_addr, ETH_ALEN);
 	wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, &data);
 }


 void wps_pbc_overlap_event(struct wps_context *wps)
 {
 	if (wps->event_cb == NULL)
 		return;

 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_OVERLAP, NULL);
 }


 void wps_pbc_timeout_event(struct wps_context *wps)
 {
 	if (wps->event_cb == NULL)
 		return;

 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_TIMEOUT, NULL);
 }


 void wps_pbc_active_event(struct wps_context *wps)
 {
 	if (wps->event_cb == NULL)
 		return;

 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_ACTIVE, NULL);
 }


 void wps_pbc_disable_event(struct wps_context *wps)
 {
 	if (wps->event_cb == NULL)
 		return;

 	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_DISABLE, NULL);
 }


 #ifdef CONFIG_WPS_OOB

 struct wpabuf * wps_get_oob_cred(struct wps_context *wps, int rf_band,
 				 int channel)
 {
 	struct wps_data data;
 	struct wpabuf *plain;

 	plain = wpabuf_alloc(500);
 	if (plain == NULL) {
 		wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB "
 			   "credential");
 		return NULL;
 	}

 	os_memset(&data, 0, sizeof(data));
 	data.wps = wps;
 	data.auth_type = wps->auth_types;
 	data.encr_type = wps->encr_types;
 	if (wps_build_cred(&data, plain) ||
 	    (rf_band && wps_build_rf_bands_attr(plain, rf_band)) ||
 	    (channel && wps_build_ap_channel(plain, channel)) ||
 	    wps_build_mac_addr(plain, wps->dev.mac_addr) ||
 	    wps_build_wfa_ext(plain, 0, NULL, 0, 0)) {
 		os_free(data.new_psk);
 		wpabuf_clear_free(plain);
 		return NULL;
 	}

 	if (wps->wps_state == WPS_STATE_NOT_CONFIGURED && data.new_psk &&
 	    wps->ap) {
 		struct wps_credential cred;

 		wpa_printf(MSG_DEBUG, "WPS: Moving to Configured state based "
 			   "on credential token generation");

 		os_memset(&cred, 0, sizeof(cred));
 		os_memcpy(cred.ssid, wps->ssid, wps->ssid_len);
 		cred.ssid_len = wps->ssid_len;
 		cred.auth_type = WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK;
 		cred.encr_type = WPS_ENCR_TKIP | WPS_ENCR_AES;
 		os_memcpy(cred.key, data.new_psk, data.new_psk_len);
 		cred.key_len = data.new_psk_len;

 		wps->wps_state = WPS_STATE_CONFIGURED;
 		wpa_hexdump_ascii_key(MSG_DEBUG,
 				      "WPS: Generated random passphrase",
 				      data.new_psk, data.new_psk_len);
 		if (wps->cred_cb)
 			wps->cred_cb(wps->cb_ctx, &cred);
 	}

 	os_free(data.new_psk);

 	return plain;
 }


 struct wpabuf * wps_build_nfc_pw_token(u16 dev_pw_id,
 				       const struct wpabuf *pubkey,
 				       const struct wpabuf *dev_pw)
 {
 	struct wpabuf *data;

 	data = wpabuf_alloc(200);
 	if (data == NULL)
 		return NULL;

 	if (wps_build_oob_dev_pw(data, dev_pw_id, pubkey,
 				 wpabuf_head(dev_pw), wpabuf_len(dev_pw)) ||
 	    wps_build_wfa_ext(data, 0, NULL, 0, 0)) {
 		wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password "
 			   "token");
 		wpabuf_clear_free(data);
 		return NULL;
 	}

 	return data;
 }


 int wps_oob_use_cred(struct wps_context *wps, struct wps_parse_attr *attr)
 {
 	struct wpabuf msg;
 	size_t i;

 	for (i = 0; i < attr->num_cred; i++) {
 		struct wps_credential local_cred;
 		struct wps_parse_attr cattr;

 		os_memset(&local_cred, 0, sizeof(local_cred));
 		wpabuf_set(&msg, attr->cred[i], attr->cred_len[i]);
 		if (wps_parse_msg(&msg, &cattr) < 0 ||
 		    wps_process_cred(&cattr, &local_cred)) {
 			wpa_printf(MSG_ERROR, "WPS: Failed to parse OOB "
 				   "credential");
 			return -1;
 		}
 		wps->cred_cb(wps->cb_ctx, &local_cred);
 	}

 	return 0;
 }


 #endif /* CONFIG_WPS_OOB */


 int wps_dev_type_str2bin(const char *str, u8 dev_type[WPS_DEV_TYPE_LEN])
 {
 	const char *pos;

 	/* <categ>-<OUI>-<subcateg> */
 	WPA_PUT_BE16(dev_type, atoi(str));
 	pos = os_strchr(str, '-');
 	if (pos == NULL)
 		return -1;
 	pos++;
 	if (hexstr2bin(pos, &dev_type[2], 4))
 		return -1;
 	pos = os_strchr(pos, '-');
 	if (pos == NULL)
 		return -1;
 	pos++;
 	WPA_PUT_BE16(&dev_type[6], atoi(pos));


 	return 0;
 }


 char * wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN], char *buf,
 			    size_t buf_len)
 {
 	int ret;

 	ret = os_snprintf(buf, buf_len, "%u-%08X-%u",
 			  WPA_GET_BE16(dev_type), WPA_GET_BE32(&dev_type[2]),
 			  WPA_GET_BE16(&dev_type[6]));
 	if (os_snprintf_error(buf_len, ret))
 		return NULL;

 	return buf;
 }


 void uuid_gen_mac_addr(const u8 *mac_addr, u8 *uuid)
 {
 	const u8 *addr[2];
 	size_t len[2];
 	u8 hash[SHA1_MAC_LEN];
 	u8 nsid[16] = {
 		0x52, 0x64, 0x80, 0xf8,
 		0xc9, 0x9b,
 		0x4b, 0xe5,
 		0xa6, 0x55,
 		0x58, 0xed, 0x5f, 0x5d, 0x60, 0x84
 	};

 	addr[0] = nsid;
 	len[0] = sizeof(nsid);
 	addr[1] = mac_addr;
 	len[1] = 6;
 	sha1_vector(2, addr, len, hash);
 	os_memcpy(uuid, hash, 16);

 	/* Version: 5 = named-based version using SHA-1 */
 	uuid[6] = (5 << 4) | (uuid[6] & 0x0f);

 	/* Variant specified in RFC 4122 */
 	uuid[8] = 0x80 | (uuid[8] & 0x3f);
 }


 u16 wps_config_methods_str2bin(const char *str)
 {
 	u16 methods = 0;

 	if (str == NULL || str[0] == '\0') {
 		/* Default to enabling methods based on build configuration */
 		methods |= WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD;
 		methods |= WPS_CONFIG_VIRT_DISPLAY;
 #ifdef CONFIG_WPS_NFC
 		methods |= WPS_CONFIG_NFC_INTERFACE;
 #endif /* CONFIG_WPS_NFC */
 #ifdef CONFIG_P2P
 		methods |= WPS_CONFIG_P2PS;
 #endif /* CONFIG_P2P */
 	} else {
 		if (os_strstr(str, "ethernet"))
 			methods |= WPS_CONFIG_ETHERNET;
 		if (os_strstr(str, "label"))
 			methods |= WPS_CONFIG_LABEL;
 		if (os_strstr(str, "display"))
 			methods |= WPS_CONFIG_DISPLAY;
 		if (os_strstr(str, "ext_nfc_token"))
 			methods |= WPS_CONFIG_EXT_NFC_TOKEN;
 		if (os_strstr(str, "int_nfc_token"))
 			methods |= WPS_CONFIG_INT_NFC_TOKEN;
 		if (os_strstr(str, "nfc_interface"))
 			methods |= WPS_CONFIG_NFC_INTERFACE;
 		if (os_strstr(str, "push_button"))
 			methods |= WPS_CONFIG_PUSHBUTTON;
 		if (os_strstr(str, "keypad"))
 			methods |= WPS_CONFIG_KEYPAD;
 		if (os_strstr(str, "virtual_display"))
 			methods |= WPS_CONFIG_VIRT_DISPLAY;
 		if (os_strstr(str, "physical_display"))
 			methods |= WPS_CONFIG_PHY_DISPLAY;
 		if (os_strstr(str, "virtual_push_button"))
 			methods |= WPS_CONFIG_VIRT_PUSHBUTTON;
 		if (os_strstr(str, "physical_push_button"))
 			methods |= WPS_CONFIG_PHY_PUSHBUTTON;
 		if (os_strstr(str, "p2ps"))
 			methods |= WPS_CONFIG_P2PS;
 	}

 	return methods;
 }


 struct wpabuf * wps_build_wsc_ack(struct wps_data *wps)
 {
 	struct wpabuf *msg;

 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_ACK");

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return NULL;

 	if (wps_build_version(msg) ||
 	    wps_build_msg_type(msg, WPS_WSC_ACK) ||
 	    wps_build_enrollee_nonce(wps, msg) ||
 	    wps_build_registrar_nonce(wps, msg) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	return msg;
 }


 struct wpabuf * wps_build_wsc_nack(struct wps_data *wps)
 {
 	struct wpabuf *msg;

 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_NACK");

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return NULL;

 	if (wps_build_version(msg) ||
 	    wps_build_msg_type(msg, WPS_WSC_NACK) ||
 	    wps_build_enrollee_nonce(wps, msg) ||
 	    wps_build_registrar_nonce(wps, msg) ||
 	    wps_build_config_error(msg, wps->config_error) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	return msg;
 }


 #ifdef CONFIG_WPS_NFC

 struct wpabuf * wps_nfc_token_build(int ndef, int id, struct wpabuf *pubkey,
 				    struct wpabuf *dev_pw)
 {
 	struct wpabuf *ret;

 	if (pubkey == NULL || dev_pw == NULL)
 		return NULL;

 	ret = wps_build_nfc_pw_token(id, pubkey, dev_pw);
 	if (ndef && ret) {
 		struct wpabuf *tmp;
 		tmp = ndef_build_wifi(ret);
 		wpabuf_free(ret);
 		if (tmp == NULL)
 			return NULL;
 		ret = tmp;
 	}

 	return ret;
 }


 int wps_nfc_gen_dh(struct wpabuf **pubkey, struct wpabuf **privkey)
 {
 	struct wpabuf *priv = NULL, *pub = NULL;
 	void *dh_ctx;

 	dh_ctx = dh5_init(&priv, &pub);
 	if (dh_ctx == NULL)
 		return -1;
 	pub = wpabuf_zeropad(pub, 192);
 	if (pub == NULL) {
 		wpabuf_free(priv);
 		dh5_free(dh_ctx);
 		return -1;
 	}
 	wpa_hexdump_buf(MSG_DEBUG, "WPS: Generated new DH pubkey", pub);
 	dh5_free(dh_ctx);

 	wpabuf_free(*pubkey);
 	*pubkey = pub;
 	wpabuf_clear_free(*privkey);
 	*privkey = priv;

 	return 0;
 }


 struct wpabuf * wps_nfc_token_gen(int ndef, int *id, struct wpabuf **pubkey,
 				  struct wpabuf **privkey,
 				  struct wpabuf **dev_pw)
 {
 	struct wpabuf *pw;
 	u16 val;

 	pw = wpabuf_alloc(WPS_OOB_DEVICE_PASSWORD_LEN);
 	if (pw == NULL)
 		return NULL;

 	if (random_get_bytes(wpabuf_put(pw, WPS_OOB_DEVICE_PASSWORD_LEN),
 			     WPS_OOB_DEVICE_PASSWORD_LEN) ||
 	    random_get_bytes((u8 *) &val, sizeof(val))) {
 		wpabuf_free(pw);
 		return NULL;
 	}

 	if (wps_nfc_gen_dh(pubkey, privkey) < 0) {
 		wpabuf_free(pw);
 		return NULL;
 	}

 	*id = 0x10 + val % 0xfff0;
 	wpabuf_clear_free(*dev_pw);
 	*dev_pw = pw;

 	return wps_nfc_token_build(ndef, *id, *pubkey, *dev_pw);
 }


 struct wpabuf * wps_build_nfc_handover_req(struct wps_context *ctx,
 					   struct wpabuf *nfc_dh_pubkey)
 {
 	struct wpabuf *msg;
 	void *len;

 	if (ctx == NULL)
 		return NULL;

 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 		   "handover request");

 	if (nfc_dh_pubkey == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 			   "configured");
 		return NULL;
 	}

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return msg;
 	len = wpabuf_put(msg, 2);

 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 				 nfc_dh_pubkey, NULL, 0) ||
 	    wps_build_uuid_e(msg, ctx->uuid) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);

 	return msg;
 }


 static int wps_build_ssid(struct wpabuf *msg, struct wps_context *wps)
 {
 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID in Connection Handover Select",
 			  wps->ssid, wps->ssid_len);
 	wpabuf_put_be16(msg, ATTR_SSID);
 	wpabuf_put_be16(msg, wps->ssid_len);
 	wpabuf_put_data(msg, wps->ssid, wps->ssid_len);
 	return 0;
 }


 static int wps_build_ap_freq(struct wpabuf *msg, int freq)
 {
 	enum hostapd_hw_mode mode;
 	u8 channel, rf_band;
 	u16 ap_channel;

 	if (freq <= 0)
 		return 0;

 	mode = ieee80211_freq_to_chan(freq, &channel);
 	if (mode == NUM_HOSTAPD_MODES)
 		return 0; /* Unknown channel */

 	if (mode == HOSTAPD_MODE_IEEE80211G || mode == HOSTAPD_MODE_IEEE80211B)
 		rf_band = WPS_RF_24GHZ;
 	else if (mode == HOSTAPD_MODE_IEEE80211A)
 		rf_band = WPS_RF_50GHZ;
 	else if (mode == HOSTAPD_MODE_IEEE80211AD)
 		rf_band = WPS_RF_60GHZ;
 	else
 		return 0; /* Unknown band */
 	ap_channel = channel;

 	if (wps_build_rf_bands_attr(msg, rf_band) ||
 	    wps_build_ap_channel(msg, ap_channel))
 		return -1;

 	return 0;
 }


 struct wpabuf * wps_build_nfc_handover_sel(struct wps_context *ctx,
 					   struct wpabuf *nfc_dh_pubkey,
 					   const u8 *bssid, int freq)
 {
 	struct wpabuf *msg;
 	void *len;

 	if (ctx == NULL)
 		return NULL;

 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 		   "handover select");

 	if (nfc_dh_pubkey == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 			   "configured");
 		return NULL;
 	}

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return msg;
 	len = wpabuf_put(msg, 2);

 	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 				 nfc_dh_pubkey, NULL, 0) ||
 	    wps_build_ssid(msg, ctx) ||
 	    wps_build_ap_freq(msg, freq) ||
 	    (bssid && wps_build_mac_addr(msg, bssid)) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);

 	return msg;
 }


 struct wpabuf * wps_build_nfc_handover_req_p2p(struct wps_context *ctx,
 					       struct wpabuf *nfc_dh_pubkey)
 {
 	struct wpabuf *msg;

 	if (ctx == NULL)
 		return NULL;

 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 		   "handover request (P2P)");

 	if (nfc_dh_pubkey == NULL) {
 		wpa_printf(MSG_DEBUG, "WPS: No NFC DH Public Key configured");
 		return NULL;
 	}

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return msg;

 	if (wps_build_manufacturer(&ctx->dev, msg) ||
 	    wps_build_model_name(&ctx->dev, msg) ||
 	    wps_build_model_number(&ctx->dev, msg) ||
 	    wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
 				 nfc_dh_pubkey, NULL, 0) ||
 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
 	    wps_build_serial_number(&ctx->dev, msg) ||
 	    wps_build_uuid_e(msg, ctx->uuid) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	return msg;
 }


 struct wpabuf * 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)
 {
 	struct wpabuf *msg;
 	const u8 *dev_pw;
 	size_t dev_pw_len;

 	if (ctx == NULL)
 		return NULL;

 	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
 		   "handover select (P2P)");

 	if (nfc_dh_pubkey == NULL ||
 	    (nfc_dev_pw_id != DEV_PW_NFC_CONNECTION_HANDOVER &&
 	     nfc_dev_pw == NULL)) {
 		wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
 			   "configured");
 		return NULL;
 	}

 	msg = wpabuf_alloc(1000);
 	if (msg == NULL)
 		return msg;

 	if (nfc_dev_pw) {
 		dev_pw = wpabuf_head(nfc_dev_pw);
 		dev_pw_len = wpabuf_len(nfc_dev_pw);
 	} else {
 		dev_pw = NULL;
 		dev_pw_len = 0;
 	}

 	if (wps_build_manufacturer(&ctx->dev, msg) ||
 	    wps_build_model_name(&ctx->dev, msg) ||
 	    wps_build_model_number(&ctx->dev, msg) ||
 	    wps_build_oob_dev_pw(msg, nfc_dev_pw_id, nfc_dh_pubkey,
 				 dev_pw, dev_pw_len) ||
 	    wps_build_rf_bands(&ctx->dev, msg, 0) ||
 	    wps_build_serial_number(&ctx->dev, msg) ||
 	    wps_build_uuid_e(msg, ctx->uuid) ||
 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
 		wpabuf_free(msg);
 		return NULL;
 	}

 	return msg;
 }

 #endif /* CONFIG_WPS_NFC */
	/*
	* Wi-Fi Protected Setup - common functionality
	* Copyright (c) 2008-2012, Jouni Malinen <j@w1.fi>
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "includes.h"

	#include "common.h"
	#include "common/defs.h"
	#include "common/ieee802_11_common.h"
	#include "crypto/aes_wrap.h"
	#include "crypto/crypto.h"
	#include "crypto/dh_group5.h"
	#include "crypto/sha1.h"
	#include "crypto/sha256.h"
	#include "crypto/random.h"
	#include "wps_i.h"
	#include "wps_dev_attr.h"


	void wps_kdf(const u8 key, const u8 label_prefix, size_t label_prefix_len,
	const char label, u8 res, size_t res_len)
	{
	u8 i_buf[4], key_bits[4];
	const u8 *addr[4];
	size_t len[4];
	int i, iter;
	u8 hash[SHA256_MAC_LEN], *opos;
	size_t left;

	WPA_PUT_BE32(key_bits, res_len * 8);

	addr[0] = i_buf;
	len[0] = sizeof(i_buf);
	addr[1] = label_prefix;
	len[1] = label_prefix_len;
	addr[2] = (const u8 *) label;
	len[2] = os_strlen(label);
	addr[3] = key_bits;
	len[3] = sizeof(key_bits);

	iter = (res_len + SHA256_MAC_LEN - 1) / SHA256_MAC_LEN;
	opos = res;
	left = res_len;

	for (i = 1; i <= iter; i++) {
	WPA_PUT_BE32(i_buf, i);
	hmac_sha256_vector(key, SHA256_MAC_LEN, 4, addr, len, hash);
	if (i < iter) {
	os_memcpy(opos, hash, SHA256_MAC_LEN);
	opos += SHA256_MAC_LEN;
	left -= SHA256_MAC_LEN;
	} else
	os_memcpy(opos, hash, left);
	}
	}


	int wps_derive_keys(struct wps_data *wps)
	{
	struct wpabuf pubkey, dh_shared;
	u8 dhkey[SHA256_MAC_LEN], kdk[SHA256_MAC_LEN];
	const u8 *addr[3];
	size_t len[3];
	u8 keys[WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN + WPS_EMSK_LEN];

	if (wps->dh_privkey == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: Own DH private key not available");
	return -1;
	}

	pubkey = wps->registrar ? wps->dh_pubkey_e : wps->dh_pubkey_r;
	if (pubkey == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: Peer DH public key not available");
	return -1;
	}

	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey);
	wpa_hexdump_buf(MSG_DEBUG, "WPS: DH peer Public Key", pubkey);
	dh_shared = dh5_derive_shared(wps->dh_ctx, pubkey, wps->dh_privkey);
	dh5_free(wps->dh_ctx);
	wps->dh_ctx = NULL;
	dh_shared = wpabuf_zeropad(dh_shared, 192);
	if (dh_shared == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: Failed to derive DH shared key");
	return -1;
	}

	/* Own DH private key is not needed anymore */
	wpabuf_clear_free(wps->dh_privkey);
	wps->dh_privkey = NULL;

	wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH shared key", dh_shared);

	/* DHKey = SHA-256(g^AB mod p) */
	addr[0] = wpabuf_head(dh_shared);
	len[0] = wpabuf_len(dh_shared);
	sha256_vector(1, addr, len, dhkey);
	wpa_hexdump_key(MSG_DEBUG, "WPS: DHKey", dhkey, sizeof(dhkey));
	wpabuf_clear_free(dh_shared);

	/* KDK = HMAC-SHA-256_DHKey(N1 \|\| EnrolleeMAC \|\| N2) */
	addr[0] = wps->nonce_e;
	len[0] = WPS_NONCE_LEN;
	addr[1] = wps->mac_addr_e;
	len[1] = ETH_ALEN;
	addr[2] = wps->nonce_r;
	len[2] = WPS_NONCE_LEN;
	hmac_sha256_vector(dhkey, sizeof(dhkey), 3, addr, len, kdk);
	wpa_hexdump_key(MSG_DEBUG, "WPS: KDK", kdk, sizeof(kdk));

	wps_kdf(kdk, NULL, 0, "Wi-Fi Easy and Secure Key Derivation",
	keys, sizeof(keys));
	os_memcpy(wps->authkey, keys, WPS_AUTHKEY_LEN);
	os_memcpy(wps->keywrapkey, keys + WPS_AUTHKEY_LEN, WPS_KEYWRAPKEY_LEN);
	os_memcpy(wps->emsk, keys + WPS_AUTHKEY_LEN + WPS_KEYWRAPKEY_LEN,
	WPS_EMSK_LEN);

	wpa_hexdump_key(MSG_DEBUG, "WPS: AuthKey",
	wps->authkey, WPS_AUTHKEY_LEN);
	wpa_hexdump_key(MSG_DEBUG, "WPS: KeyWrapKey",
	wps->keywrapkey, WPS_KEYWRAPKEY_LEN);
	wpa_hexdump_key(MSG_DEBUG, "WPS: EMSK", wps->emsk, WPS_EMSK_LEN);

	return 0;
	}


	int wps_derive_psk(struct wps_data wps, const u8 dev_passwd,
	size_t dev_passwd_len)
	{
	u8 hash[SHA256_MAC_LEN];

	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd,
	(dev_passwd_len + 1) / 2, hash) < 0)
	return -1;
	os_memcpy(wps->psk1, hash, WPS_PSK_LEN);
	if (hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN,
	dev_passwd + (dev_passwd_len + 1) / 2,
	dev_passwd_len / 2, hash) < 0)
	return -1;
	os_memcpy(wps->psk2, hash, WPS_PSK_LEN);

	wpa_hexdump_ascii_key(MSG_DEBUG, "WPS: Device Password",
	dev_passwd, dev_passwd_len);
	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK1", wps->psk1, WPS_PSK_LEN);
	wpa_hexdump_key(MSG_DEBUG, "WPS: PSK2", wps->psk2, WPS_PSK_LEN);
	return 0;
	}


	struct wpabuf * wps_decrypt_encr_settings(struct wps_data wps, const u8 encr,
	size_t encr_len)
	{
	struct wpabuf *decrypted;
	const size_t block_size = 16;
	size_t i;
	u8 pad;
	const u8 *pos;

	/* AES-128-CBC */
	if (encr == NULL \|\| encr_len < 2 * block_size \|\| encr_len % block_size)
	{
	wpa_printf(MSG_DEBUG, "WPS: No Encrypted Settings received");
	return NULL;
	}

	decrypted = wpabuf_alloc(encr_len - block_size);
	if (decrypted == NULL)
	return NULL;

	wpa_hexdump(MSG_MSGDUMP, "WPS: Encrypted Settings", encr, encr_len);
	wpabuf_put_data(decrypted, encr + block_size, encr_len - block_size);
	if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted),
	wpabuf_len(decrypted))) {
	wpabuf_clear_free(decrypted);
	return NULL;
	}

	wpa_hexdump_buf_key(MSG_MSGDUMP, "WPS: Decrypted Encrypted Settings",
	decrypted);

	pos = wpabuf_head_u8(decrypted) + wpabuf_len(decrypted) - 1;
	pad = *pos;
	if (pad > wpabuf_len(decrypted)) {
	wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad value");
	wpabuf_clear_free(decrypted);
	return NULL;
	}
	for (i = 0; i < pad; i++) {
	if (*pos-- != pad) {
	wpa_printf(MSG_DEBUG, "WPS: Invalid PKCS#5 v2.0 pad "
	"string");
	wpabuf_clear_free(decrypted);
	return NULL;
	}
	}
	decrypted->used -= pad;

	return decrypted;
	}


	/**
	* wps_pin_checksum - Compute PIN checksum
	* @pin: Seven digit PIN (i.e., eight digit PIN without the checksum digit)
	* Returns: Checksum digit
	*/
	unsigned int wps_pin_checksum(unsigned int pin)
	{
	unsigned int accum = 0;
	while (pin) {
	accum += 3 * (pin % 10);
	pin /= 10;
	accum += pin % 10;
	pin /= 10;
	}

	return (10 - accum % 10) % 10;
	}


	/**
	* wps_pin_valid - Check whether a PIN has a valid checksum
	* @pin: Eight digit PIN (i.e., including the checksum digit)
	* Returns: 1 if checksum digit is valid, or 0 if not
	*/
	unsigned int wps_pin_valid(unsigned int pin)
	{
	return wps_pin_checksum(pin / 10) == (pin % 10);
	}


	/**
	* wps_generate_pin - Generate a random PIN
	* Returns: Eight digit PIN (i.e., including the checksum digit)
	*/
	int wps_generate_pin(unsigned int *pin)
	{
	unsigned int val;

	/* Generate seven random digits for the PIN */
	if (random_get_bytes((unsigned char *) &val, sizeof(val)) < 0)
	return -1;
	val %= 10000000;

	/* Append checksum digit */
	pin = val 10 + wps_pin_checksum(val);
	return 0;
	}


	int wps_pin_str_valid(const char *pin)
	{
	const char *p;
	size_t len;

	p = pin;
	while (p >= '0' && p <= '9')
	p++;
	if (*p != '\0')
	return 0;

	len = p - pin;
	return len == 4 \|\| len == 8;
	}


	void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg,
	u16 config_error, u16 error_indication, const u8 *mac_addr)
	{
	union wps_event_data data;

	if (wps->event_cb == NULL)
	return;

	os_memset(&data, 0, sizeof(data));
	data.fail.msg = msg;
	data.fail.config_error = config_error;
	data.fail.error_indication = error_indication;
	os_memcpy(data.fail.peer_macaddr, mac_addr, ETH_ALEN);
	wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, &data);
	}


	void wps_success_event(struct wps_context wps, const u8 mac_addr)
	{
	union wps_event_data data;

	if (wps->event_cb == NULL)
	return;

	os_memset(&data, 0, sizeof(data));
	os_memcpy(data.success.peer_macaddr, mac_addr, ETH_ALEN);
	wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, &data);
	}


	void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part,
	const u8 *mac_addr)
	{
	union wps_event_data data;

	if (wps->event_cb == NULL)
	return;

	os_memset(&data, 0, sizeof(data));
	data.pwd_auth_fail.enrollee = enrollee;
	data.pwd_auth_fail.part = part;
	os_memcpy(data.pwd_auth_fail.peer_macaddr, mac_addr, ETH_ALEN);
	wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, &data);
	}


	void wps_pbc_overlap_event(struct wps_context *wps)
	{
	if (wps->event_cb == NULL)
	return;

	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_OVERLAP, NULL);
	}


	void wps_pbc_timeout_event(struct wps_context *wps)
	{
	if (wps->event_cb == NULL)
	return;

	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_TIMEOUT, NULL);
	}


	void wps_pbc_active_event(struct wps_context *wps)
	{
	if (wps->event_cb == NULL)
	return;

	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_ACTIVE, NULL);
	}


	void wps_pbc_disable_event(struct wps_context *wps)
	{
	if (wps->event_cb == NULL)
	return;

	wps->event_cb(wps->cb_ctx, WPS_EV_PBC_DISABLE, NULL);
	}


	#ifdef CONFIG_WPS_OOB

	struct wpabuf * wps_get_oob_cred(struct wps_context *wps, int rf_band,
	int channel)
	{
	struct wps_data data;
	struct wpabuf *plain;

	plain = wpabuf_alloc(500);
	if (plain == NULL) {
	wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB "
	"credential");
	return NULL;
	}

	os_memset(&data, 0, sizeof(data));
	data.wps = wps;
	data.auth_type = wps->auth_types;
	data.encr_type = wps->encr_types;
	if (wps_build_cred(&data, plain) \|\|
	(rf_band && wps_build_rf_bands_attr(plain, rf_band)) \|\|
	(channel && wps_build_ap_channel(plain, channel)) \|\|
	wps_build_mac_addr(plain, wps->dev.mac_addr) \|\|
	wps_build_wfa_ext(plain, 0, NULL, 0, 0)) {
	os_free(data.new_psk);
	wpabuf_clear_free(plain);
	return NULL;
	}

	if (wps->wps_state == WPS_STATE_NOT_CONFIGURED && data.new_psk &&
	wps->ap) {
	struct wps_credential cred;

	wpa_printf(MSG_DEBUG, "WPS: Moving to Configured state based "
	"on credential token generation");

	os_memset(&cred, 0, sizeof(cred));
	os_memcpy(cred.ssid, wps->ssid, wps->ssid_len);
	cred.ssid_len = wps->ssid_len;
	cred.auth_type = WPS_AUTH_WPAPSK \| WPS_AUTH_WPA2PSK;
	cred.encr_type = WPS_ENCR_TKIP \| WPS_ENCR_AES;
	os_memcpy(cred.key, data.new_psk, data.new_psk_len);
	cred.key_len = data.new_psk_len;

	wps->wps_state = WPS_STATE_CONFIGURED;
	wpa_hexdump_ascii_key(MSG_DEBUG,
	"WPS: Generated random passphrase",
	data.new_psk, data.new_psk_len);
	if (wps->cred_cb)
	wps->cred_cb(wps->cb_ctx, &cred);
	}

	os_free(data.new_psk);

	return plain;
	}


	struct wpabuf * wps_build_nfc_pw_token(u16 dev_pw_id,
	const struct wpabuf *pubkey,
	const struct wpabuf *dev_pw)
	{
	struct wpabuf *data;

	data = wpabuf_alloc(200);
	if (data == NULL)
	return NULL;

	if (wps_build_oob_dev_pw(data, dev_pw_id, pubkey,
	wpabuf_head(dev_pw), wpabuf_len(dev_pw)) \|\|
	wps_build_wfa_ext(data, 0, NULL, 0, 0)) {
	wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password "
	"token");
	wpabuf_clear_free(data);
	return NULL;
	}

	return data;
	}


	int wps_oob_use_cred(struct wps_context wps, struct wps_parse_attr attr)
	{
	struct wpabuf msg;
	size_t i;

	for (i = 0; i < attr->num_cred; i++) {
	struct wps_credential local_cred;
	struct wps_parse_attr cattr;

	os_memset(&local_cred, 0, sizeof(local_cred));
	wpabuf_set(&msg, attr->cred[i], attr->cred_len[i]);
	if (wps_parse_msg(&msg, &cattr) < 0 \|\|
	wps_process_cred(&cattr, &local_cred)) {
	wpa_printf(MSG_ERROR, "WPS: Failed to parse OOB "
	"credential");
	return -1;
	}
	wps->cred_cb(wps->cb_ctx, &local_cred);
	}

	return 0;
	}


	#endif /* CONFIG_WPS_OOB */


	int wps_dev_type_str2bin(const char *str, u8 dev_type[WPS_DEV_TYPE_LEN])
	{
	const char *pos;

	/* <categ>-<OUI>-<subcateg> */
	WPA_PUT_BE16(dev_type, atoi(str));
	pos = os_strchr(str, '-');
	if (pos == NULL)
	return -1;
	pos++;
	if (hexstr2bin(pos, &dev_type[2], 4))
	return -1;
	pos = os_strchr(pos, '-');
	if (pos == NULL)
	return -1;
	pos++;
	WPA_PUT_BE16(&dev_type[6], atoi(pos));


	return 0;
	}


	char * wps_dev_type_bin2str(const u8 dev_type[WPS_DEV_TYPE_LEN], char *buf,
	size_t buf_len)
	{
	int ret;

	ret = os_snprintf(buf, buf_len, "%u-%08X-%u",
	WPA_GET_BE16(dev_type), WPA_GET_BE32(&dev_type[2]),
	WPA_GET_BE16(&dev_type[6]));
	if (os_snprintf_error(buf_len, ret))
	return NULL;

	return buf;
	}


	void uuid_gen_mac_addr(const u8 mac_addr, u8 uuid)
	{
	const u8 *addr[2];
	size_t len[2];
	u8 hash[SHA1_MAC_LEN];
	u8 nsid[16] = {
	0x52, 0x64, 0x80, 0xf8,
	0xc9, 0x9b,
	0x4b, 0xe5,
	0xa6, 0x55,
	0x58, 0xed, 0x5f, 0x5d, 0x60, 0x84
	};

	addr[0] = nsid;
	len[0] = sizeof(nsid);
	addr[1] = mac_addr;
	len[1] = 6;
	sha1_vector(2, addr, len, hash);
	os_memcpy(uuid, hash, 16);

	/* Version: 5 = named-based version using SHA-1 */
	uuid[6] = (5 << 4) \| (uuid[6] & 0x0f);

	/* Variant specified in RFC 4122 */
	uuid[8] = 0x80 \| (uuid[8] & 0x3f);
	}


	u16 wps_config_methods_str2bin(const char *str)
	{
	u16 methods = 0;

	if (str == NULL \|\| str[0] == '\0') {
	/* Default to enabling methods based on build configuration */
	methods \|= WPS_CONFIG_DISPLAY \| WPS_CONFIG_KEYPAD;
	methods \|= WPS_CONFIG_VIRT_DISPLAY;
	#ifdef CONFIG_WPS_NFC
	methods \|= WPS_CONFIG_NFC_INTERFACE;
	#endif /* CONFIG_WPS_NFC */
	#ifdef CONFIG_P2P
	methods \|= WPS_CONFIG_P2PS;
	#endif /* CONFIG_P2P */
	} else {
	if (os_strstr(str, "ethernet"))
	methods \|= WPS_CONFIG_ETHERNET;
	if (os_strstr(str, "label"))
	methods \|= WPS_CONFIG_LABEL;
	if (os_strstr(str, "display"))
	methods \|= WPS_CONFIG_DISPLAY;
	if (os_strstr(str, "ext_nfc_token"))
	methods \|= WPS_CONFIG_EXT_NFC_TOKEN;
	if (os_strstr(str, "int_nfc_token"))
	methods \|= WPS_CONFIG_INT_NFC_TOKEN;
	if (os_strstr(str, "nfc_interface"))
	methods \|= WPS_CONFIG_NFC_INTERFACE;
	if (os_strstr(str, "push_button"))
	methods \|= WPS_CONFIG_PUSHBUTTON;
	if (os_strstr(str, "keypad"))
	methods \|= WPS_CONFIG_KEYPAD;
	if (os_strstr(str, "virtual_display"))
	methods \|= WPS_CONFIG_VIRT_DISPLAY;
	if (os_strstr(str, "physical_display"))
	methods \|= WPS_CONFIG_PHY_DISPLAY;
	if (os_strstr(str, "virtual_push_button"))
	methods \|= WPS_CONFIG_VIRT_PUSHBUTTON;
	if (os_strstr(str, "physical_push_button"))
	methods \|= WPS_CONFIG_PHY_PUSHBUTTON;
	if (os_strstr(str, "p2ps"))
	methods \|= WPS_CONFIG_P2PS;
	}

	return methods;
	}


	struct wpabuf * wps_build_wsc_ack(struct wps_data *wps)
	{
	struct wpabuf *msg;

	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_ACK");

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return NULL;

	if (wps_build_version(msg) \|\|
	wps_build_msg_type(msg, WPS_WSC_ACK) \|\|
	wps_build_enrollee_nonce(wps, msg) \|\|
	wps_build_registrar_nonce(wps, msg) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	return msg;
	}


	struct wpabuf * wps_build_wsc_nack(struct wps_data *wps)
	{
	struct wpabuf *msg;

	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_NACK");

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return NULL;

	if (wps_build_version(msg) \|\|
	wps_build_msg_type(msg, WPS_WSC_NACK) \|\|
	wps_build_enrollee_nonce(wps, msg) \|\|
	wps_build_registrar_nonce(wps, msg) \|\|
	wps_build_config_error(msg, wps->config_error) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	return msg;
	}


	#ifdef CONFIG_WPS_NFC

	struct wpabuf * wps_nfc_token_build(int ndef, int id, struct wpabuf *pubkey,
	struct wpabuf *dev_pw)
	{
	struct wpabuf *ret;

	if (pubkey == NULL \|\| dev_pw == NULL)
	return NULL;

	ret = wps_build_nfc_pw_token(id, pubkey, dev_pw);
	if (ndef && ret) {
	struct wpabuf *tmp;
	tmp = ndef_build_wifi(ret);
	wpabuf_free(ret);
	if (tmp == NULL)
	return NULL;
	ret = tmp;
	}

	return ret;
	}


	int wps_nfc_gen_dh(struct wpabuf pubkey, struct wpabuf privkey)
	{
	struct wpabuf priv = NULL, pub = NULL;
	void *dh_ctx;

	dh_ctx = dh5_init(&priv, &pub);
	if (dh_ctx == NULL)
	return -1;
	pub = wpabuf_zeropad(pub, 192);
	if (pub == NULL) {
	wpabuf_free(priv);
	dh5_free(dh_ctx);
	return -1;
	}
	wpa_hexdump_buf(MSG_DEBUG, "WPS: Generated new DH pubkey", pub);
	dh5_free(dh_ctx);

	wpabuf_free(*pubkey);
	*pubkey = pub;
	wpabuf_clear_free(*privkey);
	*privkey = priv;

	return 0;
	}


	struct wpabuf * wps_nfc_token_gen(int ndef, int id, struct wpabuf *pubkey,
	struct wpabuf **privkey,
	struct wpabuf **dev_pw)
	{
	struct wpabuf *pw;
	u16 val;

	pw = wpabuf_alloc(WPS_OOB_DEVICE_PASSWORD_LEN);
	if (pw == NULL)
	return NULL;

	if (random_get_bytes(wpabuf_put(pw, WPS_OOB_DEVICE_PASSWORD_LEN),
	WPS_OOB_DEVICE_PASSWORD_LEN) \|\|
	random_get_bytes((u8 *) &val, sizeof(val))) {
	wpabuf_free(pw);
	return NULL;
	}

	if (wps_nfc_gen_dh(pubkey, privkey) < 0) {
	wpabuf_free(pw);
	return NULL;
	}

	*id = 0x10 + val % 0xfff0;
	wpabuf_clear_free(*dev_pw);
	*dev_pw = pw;

	return wps_nfc_token_build(ndef, id, pubkey, *dev_pw);
	}


	struct wpabuf * wps_build_nfc_handover_req(struct wps_context *ctx,
	struct wpabuf *nfc_dh_pubkey)
	{
	struct wpabuf *msg;
	void *len;

	if (ctx == NULL)
	return NULL;

	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
	"handover request");

	if (nfc_dh_pubkey == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
	"configured");
	return NULL;
	}

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return msg;
	len = wpabuf_put(msg, 2);

	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
	nfc_dh_pubkey, NULL, 0) \|\|
	wps_build_uuid_e(msg, ctx->uuid) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);

	return msg;
	}


	static int wps_build_ssid(struct wpabuf msg, struct wps_context wps)
	{
	wpa_printf(MSG_DEBUG, "WPS: * SSID");
	wpa_hexdump_ascii(MSG_DEBUG, "WPS: SSID in Connection Handover Select",
	wps->ssid, wps->ssid_len);
	wpabuf_put_be16(msg, ATTR_SSID);
	wpabuf_put_be16(msg, wps->ssid_len);
	wpabuf_put_data(msg, wps->ssid, wps->ssid_len);
	return 0;
	}


	static int wps_build_ap_freq(struct wpabuf *msg, int freq)
	{
	enum hostapd_hw_mode mode;
	u8 channel, rf_band;
	u16 ap_channel;

	if (freq <= 0)
	return 0;

	mode = ieee80211_freq_to_chan(freq, &channel);
	if (mode == NUM_HOSTAPD_MODES)
	return 0; /* Unknown channel */

	if (mode == HOSTAPD_MODE_IEEE80211G \|\| mode == HOSTAPD_MODE_IEEE80211B)
	rf_band = WPS_RF_24GHZ;
	else if (mode == HOSTAPD_MODE_IEEE80211A)
	rf_band = WPS_RF_50GHZ;
	else if (mode == HOSTAPD_MODE_IEEE80211AD)
	rf_band = WPS_RF_60GHZ;
	else
	return 0; /* Unknown band */
	ap_channel = channel;

	if (wps_build_rf_bands_attr(msg, rf_band) \|\|
	wps_build_ap_channel(msg, ap_channel))
	return -1;

	return 0;
	}


	struct wpabuf * wps_build_nfc_handover_sel(struct wps_context *ctx,
	struct wpabuf *nfc_dh_pubkey,
	const u8 *bssid, int freq)
	{
	struct wpabuf *msg;
	void *len;

	if (ctx == NULL)
	return NULL;

	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
	"handover select");

	if (nfc_dh_pubkey == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
	"configured");
	return NULL;
	}

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return msg;
	len = wpabuf_put(msg, 2);

	if (wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
	nfc_dh_pubkey, NULL, 0) \|\|
	wps_build_ssid(msg, ctx) \|\|
	wps_build_ap_freq(msg, freq) \|\|
	(bssid && wps_build_mac_addr(msg, bssid)) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	WPA_PUT_BE16(len, wpabuf_len(msg) - 2);

	return msg;
	}


	struct wpabuf * wps_build_nfc_handover_req_p2p(struct wps_context *ctx,
	struct wpabuf *nfc_dh_pubkey)
	{
	struct wpabuf *msg;

	if (ctx == NULL)
	return NULL;

	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
	"handover request (P2P)");

	if (nfc_dh_pubkey == NULL) {
	wpa_printf(MSG_DEBUG, "WPS: No NFC DH Public Key configured");
	return NULL;
	}

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return msg;

	if (wps_build_manufacturer(&ctx->dev, msg) \|\|
	wps_build_model_name(&ctx->dev, msg) \|\|
	wps_build_model_number(&ctx->dev, msg) \|\|
	wps_build_oob_dev_pw(msg, DEV_PW_NFC_CONNECTION_HANDOVER,
	nfc_dh_pubkey, NULL, 0) \|\|
	wps_build_rf_bands(&ctx->dev, msg, 0) \|\|
	wps_build_serial_number(&ctx->dev, msg) \|\|
	wps_build_uuid_e(msg, ctx->uuid) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	return msg;
	}


	struct wpabuf * 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)
	{
	struct wpabuf *msg;
	const u8 *dev_pw;
	size_t dev_pw_len;

	if (ctx == NULL)
	return NULL;

	wpa_printf(MSG_DEBUG, "WPS: Building attributes for NFC connection "
	"handover select (P2P)");

	if (nfc_dh_pubkey == NULL \|\|
	(nfc_dev_pw_id != DEV_PW_NFC_CONNECTION_HANDOVER &&
	nfc_dev_pw == NULL)) {
	wpa_printf(MSG_DEBUG, "WPS: No NFC OOB Device Password "
	"configured");
	return NULL;
	}

	msg = wpabuf_alloc(1000);
	if (msg == NULL)
	return msg;

	if (nfc_dev_pw) {
	dev_pw = wpabuf_head(nfc_dev_pw);
	dev_pw_len = wpabuf_len(nfc_dev_pw);
	} else {
	dev_pw = NULL;
	dev_pw_len = 0;
	}

	if (wps_build_manufacturer(&ctx->dev, msg) \|\|
	wps_build_model_name(&ctx->dev, msg) \|\|
	wps_build_model_number(&ctx->dev, msg) \|\|
	wps_build_oob_dev_pw(msg, nfc_dev_pw_id, nfc_dh_pubkey,
	dev_pw, dev_pw_len) \|\|
	wps_build_rf_bands(&ctx->dev, msg, 0) \|\|
	wps_build_serial_number(&ctx->dev, msg) \|\|
	wps_build_uuid_e(msg, ctx->uuid) \|\|
	wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
	wpabuf_free(msg);
	return NULL;
	}

	return msg;
	}

	#endif /* CONFIG_WPS_NFC */