/* * Wi-Fi Protected Setup - attribute building * Copyright (c) 2008, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include "utils/common.h" #include "utils/wpa_debug.h" #include "crypto/aes_wrap.h" #include "crypto/crypto.h" #include "crypto/sha256.h" #include "crypto/random.h" #include "crypto/dh_group5.h" #include "common/ieee802_11_defs.h" #include "wps/wps_i.h" int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg, wps_key_mode_t mode) { struct wpabuf *pubkey = NULL; if (mode != WPS_CALC_KEY_NO_CALC) { wpa_printf(MSG_DEBUG, "WPS: * Public Key"); wpabuf_free(wps->dh_privkey); if (wps->dev_pw_id != DEV_PW_DEFAULT && wps->wps->dh_privkey) { wpa_printf(MSG_DEBUG, "WPS: Using pre-configured DH keys"); wps->dh_privkey = wpabuf_dup(wps->wps->dh_privkey); wps->dh_ctx = wps->wps->dh_ctx; wps->wps->dh_ctx = NULL; pubkey = wpabuf_dup(wps->wps->dh_pubkey); #ifdef CONFIG_WPS_NFC } else if (wps->dev_pw_id >= 0x10 && wps->wps->ap && wps->dev_pw_id == wps->wps->ap_nfc_dev_pw_id) { wpa_printf(MSG_DEBUG, "WPS: Using NFC password token DH keys"); wps->dh_privkey = wpabuf_dup(wps->wps->ap_nfc_dh_privkey); pubkey = wpabuf_dup(wps->wps->ap_nfc_dh_pubkey); wps->dh_ctx = dh5_init_fixed(wps->dh_privkey, pubkey); #endif /* CONFIG_WPS_NFC */ } else { wpa_printf(MSG_DEBUG, "WPS: Generate new DH keys"); wps->dh_privkey = NULL; dh5_free(wps->dh_ctx); wpa_printf(MSG_DEBUG, "build public key start\n"); wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey); wpa_printf(MSG_DEBUG, "build public key finish\n"); pubkey = wpabuf_zeropad(pubkey, 192); } if (wps->dh_ctx == NULL || wps->dh_privkey == NULL || pubkey == NULL) { wpa_printf(MSG_DEBUG, "WPS: Failed to initialize " "Diffie-Hellman handshake"); wpabuf_free(pubkey); return -1; } wpa_hexdump_buf_key(MSG_DEBUG, "WPS: DH Private Key", wps->dh_privkey); wpa_hexdump_buf(MSG_DEBUG, "WPS: DH own Public Key", pubkey); if (wps->registrar) { wpabuf_free(wps->dh_pubkey_r); wps->dh_pubkey_r = pubkey; } else { wpabuf_free(wps->dh_pubkey_e); wps->dh_pubkey_e = pubkey; } } if (mode != WPS_CALC_KEY_PRE_CALC) { if (wps->registrar) pubkey = wps->dh_pubkey_r; else pubkey = wps->dh_pubkey_e; wpabuf_put_be16(msg, ATTR_PUBLIC_KEY); wpabuf_put_be16(msg, wpabuf_len(pubkey)); wpabuf_put_buf(msg, pubkey); } return 0; } int wps_build_req_type(struct wpabuf *msg, enum wps_request_type type) { wpa_printf(MSG_DEBUG, "WPS: * Request Type"); wpabuf_put_be16(msg, ATTR_REQUEST_TYPE); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, type); return 0; } int wps_build_resp_type(struct wpabuf *msg, enum wps_response_type type) { wpa_printf(MSG_DEBUG, "WPS: * Response Type (%d)", type); wpabuf_put_be16(msg, ATTR_RESPONSE_TYPE); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, type); return 0; } int wps_build_config_methods(struct wpabuf *msg, u16 methods) { wpa_printf(MSG_DEBUG, "WPS: * Config Methods (%x)", methods); wpabuf_put_be16(msg, ATTR_CONFIG_METHODS); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, methods); return 0; } int wps_build_uuid_e(struct wpabuf *msg, const u8 *uuid) { wpa_printf(MSG_DEBUG, "WPS: * UUID-E"); wpabuf_put_be16(msg, ATTR_UUID_E); wpabuf_put_be16(msg, WPS_UUID_LEN); wpabuf_put_data(msg, uuid, WPS_UUID_LEN); return 0; } int wps_build_dev_password_id(struct wpabuf *msg, u16 id) { wpa_printf(MSG_DEBUG, "WPS: * Device Password ID (%d)", id); wpabuf_put_be16(msg, ATTR_DEV_PASSWORD_ID); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, id); return 0; } int wps_build_config_error(struct wpabuf *msg, u16 err) { wpa_printf(MSG_DEBUG, "WPS: * Configuration Error (%d)", err); wpabuf_put_be16(msg, ATTR_CONFIG_ERROR); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, err); return 0; } int wps_build_authenticator(struct wps_data *wps, struct wpabuf *msg) { u8 hash[SHA256_MAC_LEN]; const u8 *addr[2]; size_t len[2]; if (wps->last_msg == NULL) { wpa_printf(MSG_DEBUG, "WPS: Last message not available for " "building authenticator"); return -1; } /* Authenticator = HMAC-SHA256_AuthKey(M_prev || M_curr*) * (M_curr* is M_curr without the Authenticator attribute) */ addr[0] = wpabuf_head(wps->last_msg); len[0] = wpabuf_len(wps->last_msg); addr[1] = wpabuf_head(msg); len[1] = wpabuf_len(msg); hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 2, addr, len, hash); wpa_printf(MSG_DEBUG, "WPS: * Authenticator"); wpabuf_put_be16(msg, ATTR_AUTHENTICATOR); wpabuf_put_be16(msg, WPS_AUTHENTICATOR_LEN); wpabuf_put_data(msg, hash, WPS_AUTHENTICATOR_LEN); return 0; } int wps_build_version(struct wpabuf *msg) { /* * Note: This attribute is deprecated and set to hardcoded 0x10 for * backwards compatibility reasons. The real version negotiation is * done with Version2. */ wpa_printf(MSG_DEBUG, "WPS: * Version (hardcoded 0x10)"); wpabuf_put_be16(msg, ATTR_VERSION); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, 0x10); return 0; } int wps_build_wfa_ext(struct wpabuf *msg, int req_to_enroll, const u8 *auth_macs, size_t auth_macs_count) { #ifdef CONFIG_WPS2 u8 *len; wpabuf_put_be16(msg, ATTR_VENDOR_EXT); len = wpabuf_put(msg, 2); /* to be filled */ wpabuf_put_be24(msg, WPS_VENDOR_ID_WFA); wpa_printf(MSG_DEBUG, "WPS: * Version2 (0x%x)", WPS_VERSION); wpabuf_put_u8(msg, WFA_ELEM_VERSION2); wpabuf_put_u8(msg, 1); wpabuf_put_u8(msg, WPS_VERSION); if (req_to_enroll) { wpa_printf(MSG_DEBUG, "WPS: * Request to Enroll (1)"); wpabuf_put_u8(msg, WFA_ELEM_REQUEST_TO_ENROLL); wpabuf_put_u8(msg, 1); wpabuf_put_u8(msg, 1); } if (auth_macs && auth_macs_count) { size_t i; wpa_printf(MSG_DEBUG, "WPS: * AuthorizedMACs (count=%d)", (int) auth_macs_count); wpabuf_put_u8(msg, WFA_ELEM_AUTHORIZEDMACS); wpabuf_put_u8(msg, auth_macs_count * ETH_ALEN); wpabuf_put_data(msg, auth_macs, auth_macs_count * ETH_ALEN); for (i = 0; i < auth_macs_count; i++) wpa_printf(MSG_DEBUG, "WPS: AuthorizedMAC: " MACSTR, MAC2STR(&auth_macs[i * ETH_ALEN])); } WPA_PUT_BE16(len, (u8 *) wpabuf_put(msg, 0) - len - 2); #endif /* CONFIG_WPS2 */ #ifdef CONFIG_WPS_TESTING if (WPS_VERSION > 0x20) { wpa_printf(MSG_DEBUG, "WPS: * Extensibility Testing - extra " "attribute"); wpabuf_put_be16(msg, ATTR_EXTENSIBILITY_TEST); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, 42); } #endif /* CONFIG_WPS_TESTING */ return 0; } int wps_build_msg_type(struct wpabuf *msg, enum wps_msg_type msg_type) { wpa_printf(MSG_DEBUG, "WPS: * Message Type (%d)", msg_type); wpabuf_put_be16(msg, ATTR_MSG_TYPE); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, msg_type); return 0; } int wps_build_enrollee_nonce(struct wps_data *wps, struct wpabuf *msg) { wpa_printf(MSG_DEBUG, "WPS: * Enrollee Nonce"); wpabuf_put_be16(msg, ATTR_ENROLLEE_NONCE); wpabuf_put_be16(msg, WPS_NONCE_LEN); wpabuf_put_data(msg, wps->nonce_e, WPS_NONCE_LEN); return 0; } int wps_build_registrar_nonce(struct wps_data *wps, struct wpabuf *msg) { wpa_printf(MSG_DEBUG, "WPS: * Registrar Nonce"); wpabuf_put_be16(msg, ATTR_REGISTRAR_NONCE); wpabuf_put_be16(msg, WPS_NONCE_LEN); wpabuf_put_data(msg, wps->nonce_r, WPS_NONCE_LEN); return 0; } int wps_build_auth_type_flags(struct wps_data *wps, struct wpabuf *msg) { u16 auth_types = WPS_AUTH_TYPES; #ifdef CONFIG_WPS2 auth_types &= ~WPS_AUTH_SHARED; #endif /* CONFIG_WPS2 */ wpa_printf(MSG_DEBUG, "WPS: * Authentication Type Flags"); wpabuf_put_be16(msg, ATTR_AUTH_TYPE_FLAGS); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, auth_types); return 0; } int wps_build_encr_type_flags(struct wps_data *wps, struct wpabuf *msg) { u16 encr_types = WPS_ENCR_TYPES; #ifdef CONFIG_WPS2 encr_types &= ~WPS_ENCR_WEP; #endif /* CONFIG_WPS2 */ wpa_printf(MSG_DEBUG, "WPS: * Encryption Type Flags"); wpabuf_put_be16(msg, ATTR_ENCR_TYPE_FLAGS); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, encr_types); return 0; } int wps_build_conn_type_flags(struct wps_data *wps, struct wpabuf *msg) { wpa_printf(MSG_DEBUG, "WPS: * Connection Type Flags"); wpabuf_put_be16(msg, ATTR_CONN_TYPE_FLAGS); wpabuf_put_be16(msg, 1); wpabuf_put_u8(msg, WPS_CONN_ESS); return 0; } int wps_build_assoc_state(struct wps_data *wps, struct wpabuf *msg) { wpa_printf(MSG_DEBUG, "WPS: * Association State"); wpabuf_put_be16(msg, ATTR_ASSOC_STATE); wpabuf_put_be16(msg, 2); wpabuf_put_be16(msg, WPS_ASSOC_NOT_ASSOC); return 0; } int wps_build_key_wrap_auth(struct wps_data *wps, struct wpabuf *msg) { u8 hash[SHA256_MAC_LEN]; wpa_printf(MSG_DEBUG, "WPS: * Key Wrap Authenticator"); hmac_sha256(wps->authkey, WPS_AUTHKEY_LEN, wpabuf_head(msg), wpabuf_len(msg), hash); wpabuf_put_be16(msg, ATTR_KEY_WRAP_AUTH); wpabuf_put_be16(msg, WPS_KWA_LEN); wpabuf_put_data(msg, hash, WPS_KWA_LEN); return 0; } int wps_build_encr_settings(struct wps_data *wps, struct wpabuf *msg, struct wpabuf *plain) { size_t pad_len; const size_t block_size = 16; u8 *iv, *data; wpa_printf(MSG_DEBUG, "WPS: * Encrypted Settings"); /* PKCS#5 v2.0 pad */ pad_len = block_size - wpabuf_len(plain) % block_size; os_memset(wpabuf_put(plain, pad_len), pad_len, pad_len); wpabuf_put_be16(msg, ATTR_ENCR_SETTINGS); wpabuf_put_be16(msg, block_size + wpabuf_len(plain)); iv = wpabuf_put(msg, block_size); if (random_get_bytes(iv, block_size) < 0) return -1; data = wpabuf_put(msg, 0); wpabuf_put_buf(msg, plain); wpa_printf(MSG_DEBUG, "WPS: * AES 128 Encrypted Settings"); if (aes_128_cbc_encrypt(wps->keywrapkey, iv, data, wpabuf_len(plain))) return -1; return 0; } #ifdef CONFIG_WPS_OOB int wps_build_oob_dev_pw(struct wpabuf *msg, u16 dev_pw_id, const struct wpabuf *pubkey, const u8 *dev_pw, size_t dev_pw_len) { size_t hash_len; const u8 *addr[1]; u8 pubkey_hash[WPS_HASH_LEN]; addr[0] = wpabuf_head(pubkey); hash_len = wpabuf_len(pubkey); sha256_vector(1, addr, &hash_len, pubkey_hash); wpabuf_put_be16(msg, ATTR_OOB_DEVICE_PASSWORD); wpabuf_put_be16(msg, WPS_OOB_PUBKEY_HASH_LEN + 2 + dev_pw_len); wpabuf_put_data(msg, pubkey_hash, WPS_OOB_PUBKEY_HASH_LEN); wpabuf_put_be16(msg, dev_pw_id); wpabuf_put_data(msg, dev_pw, dev_pw_len); return 0; } #endif /* CONFIG_WPS_OOB */ /* Encapsulate WPS IE data with one (or more, if needed) IE headers */ struct wpabuf * wps_ie_encapsulate(struct wpabuf *data) { struct wpabuf *ie; const u8 *pos, *end; ie = wpabuf_alloc(wpabuf_len(data) + 100); if (ie == NULL) { wpabuf_free(data); return NULL; } pos = wpabuf_head(data); end = pos + wpabuf_len(data); while (end > pos) { size_t frag_len = end - pos; if (frag_len > 251) frag_len = 251; wpabuf_put_u8(ie, WLAN_EID_VENDOR_SPECIFIC); wpabuf_put_u8(ie, 4 + frag_len); wpabuf_put_be32(ie, WPS_DEV_OUI_WFA); wpabuf_put_data(ie, pos, frag_len); pos += frag_len; } wpabuf_free(data); return ie; }