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/*
* Wi-Fi Protected Setup - attribute building
* Copyright (c) 2008, 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 "crypto/aes_wrap.h"
#include "crypto/crypto.h"
#include "crypto/dh_group5.h"
#include "crypto/sha256.h"
#include "crypto/random.h"
#include "common/ieee802_11_defs.h"
#include "wps_i.h"
int wps_build_public_key(struct wps_data *wps, struct wpabuf *msg)
{
struct wpabuf *pubkey;
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);
wps->dh_ctx = dh5_init(&wps->dh_privkey, &pubkey);
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);
wpabuf_put_be16(msg, ATTR_PUBLIC_KEY);
wpabuf_put_be16(msg, wpabuf_len(pubkey));
wpabuf_put_buf(msg, 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;
}
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);
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;
}