/* * Wi-Fi Protected Setup - common functionality * Copyright (c) 2008-2012, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include #include "utils/includes.h" #include "utils/common.h" #include "crypto/aes_wrap.h" #include "crypto/crypto.h" #include "crypto/sha1.h" #include "crypto/sha256.h" #include "crypto/dh_group5.h" #include "crypto/random.h" #include "wps/wps_i.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 */ /* * due to the public key calculated when wps start, it will not calculate anymore even when we build M1 message, also calculate the key need take a long time * which would cause WPS fail, so we clean the key after WPS finished . */ #ifndef ESP32_WORKAROUND wpabuf_free(wps->dh_privkey); wps->dh_privkey = NULL; #endif //ESP32_WORKAROUND 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_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; } void wps_derive_psk(struct wps_data *wps, const u8 *dev_passwd, size_t dev_passwd_len) { u8 hash[SHA256_MAC_LEN]; hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd, (dev_passwd_len + 1) / 2, hash); os_memcpy(wps->psk1, hash, WPS_PSK_LEN); hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, dev_passwd + (dev_passwd_len + 1) / 2, dev_passwd_len / 2, hash); 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); } 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); wpa_printf(MSG_DEBUG, "WPS: AES Decrypt setting"); if (aes_128_cbc_decrypt(wps->keywrapkey, encr, wpabuf_mhead(decrypted), wpabuf_len(decrypted))) { wpabuf_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_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_free(decrypted); return NULL; } } decrypted->used -= pad; return decrypted; } #ifdef CONFIG_WPS_PIN /** * 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) */ unsigned int wps_generate_pin(void) { 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 */ return val * 10 + wps_pin_checksum(val); } 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; } #endif void wps_fail_event(struct wps_context *wps, enum wps_msg_type msg, u16 config_error, u16 error_indication) { union wps_event_data *data; data = (union wps_event_data *)os_zalloc(sizeof(union wps_event_data)); if (data == NULL) return; if (wps->event_cb == NULL) { os_free(data); return; } os_memset(data, 0, sizeof(union wps_event_data)); data->fail.msg = msg; data->fail.config_error = config_error; data->fail.error_indication = error_indication; wps->event_cb(wps->cb_ctx, WPS_EV_FAIL, data); os_free(data); } void wps_success_event(struct wps_context *wps) { if (wps->event_cb == NULL) return; wps->event_cb(wps->cb_ctx, WPS_EV_SUCCESS, NULL); } void wps_pwd_auth_fail_event(struct wps_context *wps, int enrollee, int part) { union wps_event_data *data; data = (union wps_event_data *)os_zalloc(sizeof(union wps_event_data)); if (data == NULL) return; if (wps->event_cb == NULL) { os_free(data); return; } os_memset(data, 0, sizeof(union wps_event_data)); data->pwd_auth_fail.enrollee = enrollee; data->pwd_auth_fail.part = part; wps->event_cb(wps->cb_ctx, WPS_EV_PWD_AUTH_FAIL, data); os_free(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); } #ifdef CONFIG_WPS_OOB struct wpabuf * wps_get_oob_cred(struct wps_context *wps) { struct wps_data *data; struct wpabuf *plain; data = (struct wps_data *)os_zalloc(sizeof(struct wps_data)); if (data == NULL) return NULL; plain = wpabuf_alloc(500); if (plain == NULL) { os_free(data); wpa_printf(MSG_ERROR, "WPS: Failed to allocate memory for OOB " "credential"); return NULL; } os_memset(data, 0, sizeof(struct wps_data)); data->wps = wps; data->auth_type = wps->auth_types; data->encr_type = wps->encr_types; if (wps_build_version(plain) || wps_build_cred(data, plain) || wps_build_wfa_ext(plain, 0, NULL, 0)) { wpabuf_free(plain); os_free(data); return NULL; } os_free(data); return plain; } #ifdef CONFIG_WPS_NFC 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_version(data) || 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)) { wpa_printf(MSG_ERROR, "WPS: Failed to build NFC password " "token"); wpabuf_free(data); return NULL; } return data; } #endif 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; /* -- */ WPA_PUT_BE16(dev_type, atoi(str)); pos = (char *)os_strchr(str, '-'); if (pos == NULL) return -1; pos++; if (hexstr2bin(pos, &dev_type[2], 4)) return -1; pos = (char *)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 = 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 (ret < 0 || (unsigned int) ret >= buf_len) 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) { /* Default to enabling methods based on build configuration */ methods |= WPS_CONFIG_DISPLAY | WPS_CONFIG_KEYPAD; #ifdef CONFIG_WPS2 methods |= WPS_CONFIG_VIRT_DISPLAY; #endif /* CONFIG_WPS2 */ #ifdef CONFIG_WPS_NFC methods |= WPS_CONFIG_NFC_INTERFACE; #endif /* CONFIG_WPS_NFC */ } 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; #ifdef CONFIG_WPS2 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; #endif /* CONFIG_WPS2 */ } 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)) { 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)) { wpabuf_free(msg); return NULL; } return msg; } #ifdef CONFIG_WPS_NFC struct wpabuf * wps_nfc_token_gen(int ndef, int *id, struct wpabuf **pubkey, struct wpabuf **privkey, struct wpabuf **dev_pw) { struct wpabuf *priv = NULL, *pub = NULL, *pw, *ret; void *dh_ctx; 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; } dh_ctx = dh5_init(&priv, &pub); if (dh_ctx == NULL) { wpabuf_free(pw); return NULL; } dh5_free(dh_ctx); *id = 0x10 + val % 0xfff0; wpabuf_free(*pubkey); *pubkey = pub; wpabuf_free(*privkey); *privkey = priv; wpabuf_free(*dev_pw); *dev_pw = pw; 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; } #endif /* CONFIG_WPS_NFC */