hostap/wpa_supplicant/mesh_rsn.c

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/*
* WPA Supplicant - Mesh RSN routines
* Copyright (c) 2013-2014, cozybit, Inc. All rights reserved.
*
* 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/eloop.h"
#include "crypto/sha256.h"
#include "crypto/random.h"
#include "crypto/aes.h"
#include "crypto/aes_siv.h"
#include "rsn_supp/wpa.h"
#include "ap/hostapd.h"
#include "ap/wpa_auth.h"
#include "ap/sta_info.h"
#include "ap/ieee802_11.h"
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "wpas_glue.h"
#include "mesh_mpm.h"
#include "mesh_rsn.h"
#define MESH_AUTH_TIMEOUT 10
#define MESH_AUTH_RETRY 3
void mesh_auth_timer(void *eloop_ctx, void *user_data)
{
struct wpa_supplicant *wpa_s = eloop_ctx;
struct sta_info *sta = user_data;
struct hostapd_data *hapd;
if (sta->sae->state != SAE_ACCEPTED) {
wpa_printf(MSG_DEBUG, "AUTH: Re-authenticate with " MACSTR
" (attempt %d) ",
MAC2STR(sta->addr), sta->sae_auth_retry);
wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_FAILURE "addr=" MACSTR,
MAC2STR(sta->addr));
if (sta->sae_auth_retry < MESH_AUTH_RETRY) {
mesh_rsn_auth_sae_sta(wpa_s, sta);
} else {
hapd = wpa_s->ifmsh->bss[0];
if (sta->sae_auth_retry > MESH_AUTH_RETRY) {
ap_free_sta(hapd, sta);
return;
}
/* block the STA if exceeded the number of attempts */
wpa_mesh_set_plink_state(wpa_s, sta, PLINK_BLOCKED);
sta->sae->state = SAE_NOTHING;
wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_BLOCKED "addr="
MACSTR " duration=%d",
MAC2STR(sta->addr),
hapd->conf->ap_max_inactivity);
}
sta->sae_auth_retry++;
}
}
static void auth_logger(void *ctx, const u8 *addr, logger_level level,
const char *txt)
{
if (addr)
wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
MAC2STR(addr), txt);
else
wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
}
static const u8 *auth_get_psk(void *ctx, const u8 *addr,
const u8 *p2p_dev_addr, const u8 *prev_psk,
size_t *psk_len, int *vlan_id)
{
struct mesh_rsn *mesh_rsn = ctx;
struct hostapd_data *hapd = mesh_rsn->wpa_s->ifmsh->bss[0];
struct sta_info *sta = ap_get_sta(hapd, addr);
if (psk_len)
*psk_len = PMK_LEN;
if (vlan_id)
*vlan_id = 0;
wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
__func__, MAC2STR(addr), prev_psk);
if (sta && sta->auth_alg == WLAN_AUTH_SAE) {
if (!sta->sae || prev_psk)
return NULL;
return sta->sae->pmk;
}
return NULL;
}
static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
const u8 *addr, int idx, u8 *key, size_t key_len)
{
struct mesh_rsn *mesh_rsn = ctx;
u8 seq[6];
os_memset(seq, 0, sizeof(seq));
if (addr) {
wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
" key_idx=%d)",
__func__, alg, MAC2STR(addr), idx);
} else {
wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
__func__, alg, idx);
}
wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
return wpa_drv_set_key(mesh_rsn->wpa_s, alg, addr, idx,
1, seq, 6, key, key_len);
}
static int auth_start_ampe(void *ctx, const u8 *addr)
{
struct mesh_rsn *mesh_rsn = ctx;
struct hostapd_data *hapd;
struct sta_info *sta;
if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH)
return -1;
hapd = mesh_rsn->wpa_s->ifmsh->bss[0];
sta = ap_get_sta(hapd, addr);
if (sta)
eloop_cancel_timeout(mesh_auth_timer, mesh_rsn->wpa_s, sta);
mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr);
return 0;
}
static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
enum mfp_options ieee80211w, int ocv)
{
struct wpa_auth_config conf;
static const struct wpa_auth_callbacks cb = {
.logger = auth_logger,
.get_psk = auth_get_psk,
.set_key = auth_set_key,
.start_ampe = auth_start_ampe,
};
u8 seq[6] = {};
wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
os_memset(&conf, 0, sizeof(conf));
conf.wpa = WPA_PROTO_RSN;
conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE;
conf.wpa_pairwise = rsn->pairwise_cipher;
conf.rsn_pairwise = rsn->pairwise_cipher;
conf.wpa_group = rsn->group_cipher;
conf.eapol_version = 0;
conf.wpa_group_rekey = -1;
conf.wpa_group_update_count = 4;
conf.wpa_pairwise_update_count = 4;
conf.ieee80211w = ieee80211w;
if (ieee80211w != NO_MGMT_FRAME_PROTECTION)
conf.group_mgmt_cipher = rsn->mgmt_group_cipher;
#ifdef CONFIG_OCV
conf.ocv = ocv;
#endif /* CONFIG_OCV */
rsn->auth = wpa_init(addr, &conf, &cb, rsn);
if (rsn->auth == NULL) {
wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
return -1;
}
/* TODO: support rekeying */
rsn->mgtk_len = wpa_cipher_key_len(conf.wpa_group);
if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0)
return -1;
rsn->mgtk_key_id = 1;
if (ieee80211w != NO_MGMT_FRAME_PROTECTION) {
rsn->igtk_len = wpa_cipher_key_len(conf.group_mgmt_cipher);
if (random_get_bytes(rsn->igtk, rsn->igtk_len) < 0)
return -1;
rsn->igtk_key_id = 4;
/* group mgmt */
wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX IGTK",
rsn->igtk, rsn->igtk_len);
wpa_drv_set_key(rsn->wpa_s,
wpa_cipher_to_alg(rsn->mgmt_group_cipher), NULL,
rsn->igtk_key_id, 1,
seq, sizeof(seq), rsn->igtk, rsn->igtk_len);
}
/* group privacy / data frames */
wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK",
rsn->mgtk, rsn->mgtk_len);
wpa_drv_set_key(rsn->wpa_s, wpa_cipher_to_alg(rsn->group_cipher), NULL,
rsn->mgtk_key_id, 1, seq, sizeof(seq),
rsn->mgtk, rsn->mgtk_len);
return 0;
}
static void mesh_rsn_deinit(struct mesh_rsn *rsn)
{
os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk));
rsn->mgtk_len = 0;
os_memset(rsn->igtk, 0, sizeof(rsn->igtk));
rsn->igtk_len = 0;
if (rsn->auth)
wpa_deinit(rsn->auth);
}
struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s,
struct mesh_conf *conf)
{
struct mesh_rsn *mesh_rsn;
struct hostapd_data *bss = wpa_s->ifmsh->bss[0];
const u8 *ie;
size_t ie_len;
#ifdef CONFIG_PMKSA_CACHE_EXTERNAL
struct external_pmksa_cache *entry;
#endif /* CONFIG_PMKSA_CACHE_EXTERNAL */
mesh_rsn = os_zalloc(sizeof(*mesh_rsn));
if (mesh_rsn == NULL)
return NULL;
mesh_rsn->wpa_s = wpa_s;
mesh_rsn->pairwise_cipher = conf->pairwise_cipher;
mesh_rsn->group_cipher = conf->group_cipher;
mesh_rsn->mgmt_group_cipher = conf->mgmt_group_cipher;
if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr,
conf->ieee80211w, conf->ocv) < 0) {
mesh_rsn_deinit(mesh_rsn);
os_free(mesh_rsn);
return NULL;
}
bss->wpa_auth = mesh_rsn->auth;
#ifdef CONFIG_PMKSA_CACHE_EXTERNAL
while ((entry = dl_list_last(&wpa_s->mesh_external_pmksa_cache,
struct external_pmksa_cache,
list)) != NULL) {
int ret;
ret = wpa_auth_pmksa_add_entry(bss->wpa_auth,
entry->pmksa_cache);
dl_list_del(&entry->list);
os_free(entry);
if (ret < 0)
return NULL;
}
#endif /* CONFIG_PMKSA_CACHE_EXTERNAL */
ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len);
conf->rsn_ie = (u8 *) ie;
conf->rsn_ie_len = ie_len;
wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid);
return mesh_rsn;
}
static int index_within_array(const int *array, int idx)
{
int i;
for (i = 0; i < idx; i++) {
if (array[i] == -1)
return 0;
}
return 1;
}
static int mesh_rsn_sae_group(struct wpa_supplicant *wpa_s,
struct sae_data *sae)
{
int *groups = wpa_s->ifmsh->bss[0]->conf->sae_groups;
/* Configuration may have changed, so validate current index */
if (!index_within_array(groups, wpa_s->mesh_rsn->sae_group_index))
return -1;
for (;;) {
int group = groups[wpa_s->mesh_rsn->sae_group_index];
if (group <= 0)
break;
if (sae_set_group(sae, group) == 0) {
wpa_dbg(wpa_s, MSG_DEBUG, "SME: Selected SAE group %d",
sae->group);
return 0;
}
wpa_s->mesh_rsn->sae_group_index++;
}
return -1;
}
static int mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s,
struct wpa_ssid *ssid,
struct sta_info *sta)
{
const char *password;
password = ssid->sae_password;
if (!password)
password = ssid->passphrase;
if (!password) {
wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available");
return -1;
}
if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) {
wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group");
return -1;
}
if (sta->sae->tmp && !sta->sae->tmp->pw_id && ssid->sae_password_id) {
sta->sae->tmp->pw_id = os_strdup(ssid->sae_password_id);
if (!sta->sae->tmp->pw_id)
return -1;
}
return sae_prepare_commit(wpa_s->own_addr, sta->addr,
(u8 *) password, os_strlen(password),
ssid->sae_password_id,
sta->sae);
}
/* initiate new SAE authentication with sta */
int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s,
struct sta_info *sta)
{
struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
struct wpa_ssid *ssid = wpa_s->current_ssid;
struct rsn_pmksa_cache_entry *pmksa;
unsigned int rnd;
int ret;
if (!ssid) {
wpa_msg(wpa_s, MSG_DEBUG,
"AUTH: No current_ssid known to initiate new SAE");
return -1;
}
if (!sta->sae) {
sta->sae = os_zalloc(sizeof(*sta->sae));
if (sta->sae == NULL)
return -1;
}
pmksa = wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL);
if (pmksa) {
if (!sta->wpa_sm)
sta->wpa_sm = wpa_auth_sta_init(hapd->wpa_auth,
sta->addr, NULL);
if (!sta->wpa_sm) {
wpa_printf(MSG_ERROR,
"mesh: Failed to initialize RSN state machine");
return -1;
}
wpa_printf(MSG_DEBUG,
"AUTH: Mesh PMKSA cache entry found for " MACSTR
" - try to use PMKSA caching instead of new SAE authentication",
MAC2STR(sta->addr));
wpa_auth_pmksa_set_to_sm(pmksa, sta->wpa_sm, hapd->wpa_auth,
sta->sae->pmkid, sta->sae->pmk);
sae_accept_sta(hapd, sta);
sta->mesh_sae_pmksa_caching = 1;
return 0;
}
sta->mesh_sae_pmksa_caching = 0;
if (mesh_rsn_build_sae_commit(wpa_s, ssid, sta))
return -1;
wpa_msg(wpa_s, MSG_DEBUG,
"AUTH: started authentication with SAE peer: " MACSTR,
MAC2STR(sta->addr));
ret = auth_sae_init_committed(hapd, sta);
if (ret)
return ret;
eloop_cancel_timeout(mesh_auth_timer, wpa_s, sta);
rnd = rand() % MESH_AUTH_TIMEOUT;
eloop_register_timeout(MESH_AUTH_TIMEOUT + rnd, 0, mesh_auth_timer,
wpa_s, sta);
return 0;
}
void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid)
{
os_memcpy(pmkid, sta->sae->pmkid, SAE_PMKID_LEN);
}
static void
mesh_rsn_derive_aek(struct mesh_rsn *rsn, struct sta_info *sta)
{
u8 *myaddr = rsn->wpa_s->own_addr;
u8 *peer = sta->addr;
u8 *addr1, *addr2;
u8 context[RSN_SELECTOR_LEN + 2 * ETH_ALEN], *ptr = context;
/*
* AEK = KDF-Hash-256(PMK, "AEK Derivation", Selected AKM Suite ||
* min(localMAC, peerMAC) || max(localMAC, peerMAC))
*/
/* Selected AKM Suite: SAE */
RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE);
ptr += RSN_SELECTOR_LEN;
if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
addr1 = myaddr;
addr2 = peer;
} else {
addr1 = peer;
addr2 = myaddr;
}
os_memcpy(ptr, addr1, ETH_ALEN);
ptr += ETH_ALEN;
os_memcpy(ptr, addr2, ETH_ALEN);
sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), "AEK Derivation",
context, sizeof(context), sta->aek, sizeof(sta->aek));
}
/* derive mesh temporal key from pmk */
int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta)
{
u8 *ptr;
u8 *min, *max;
u8 *myaddr = wpa_s->own_addr;
u8 *peer = sta->addr;
u8 context[2 * WPA_NONCE_LEN + 2 * 2 + RSN_SELECTOR_LEN + 2 * ETH_ALEN];
/*
* MTK = KDF-Hash-Length(PMK, "Temporal Key Derivation", min(localNonce,
* peerNonce) || max(localNonce, peerNonce) || min(localLinkID,
* peerLinkID) || max(localLinkID, peerLinkID) || Selected AKM Suite ||
* min(localMAC, peerMAC) || max(localMAC, peerMAC))
*/
ptr = context;
if (os_memcmp(sta->my_nonce, sta->peer_nonce, WPA_NONCE_LEN) < 0) {
min = sta->my_nonce;
max = sta->peer_nonce;
} else {
min = sta->peer_nonce;
max = sta->my_nonce;
}
os_memcpy(ptr, min, WPA_NONCE_LEN);
ptr += WPA_NONCE_LEN;
os_memcpy(ptr, max, WPA_NONCE_LEN);
ptr += WPA_NONCE_LEN;
if (sta->my_lid < sta->peer_lid) {
WPA_PUT_LE16(ptr, sta->my_lid);
ptr += 2;
WPA_PUT_LE16(ptr, sta->peer_lid);
ptr += 2;
} else {
WPA_PUT_LE16(ptr, sta->peer_lid);
ptr += 2;
WPA_PUT_LE16(ptr, sta->my_lid);
ptr += 2;
}
/* Selected AKM Suite: SAE */
RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE);
ptr += RSN_SELECTOR_LEN;
if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
min = myaddr;
max = peer;
} else {
min = peer;
max = myaddr;
}
os_memcpy(ptr, min, ETH_ALEN);
ptr += ETH_ALEN;
os_memcpy(ptr, max, ETH_ALEN);
sta->mtk_len = wpa_cipher_key_len(wpa_s->mesh_rsn->pairwise_cipher);
sha256_prf(sta->sae->pmk, SAE_PMK_LEN,
"Temporal Key Derivation", context, sizeof(context),
sta->mtk, sta->mtk_len);
return 0;
}
void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta)
{
if (random_get_bytes(sta->my_nonce, WPA_NONCE_LEN) < 0) {
wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce");
/* TODO: How to handle this more cleanly? */
}
os_memset(sta->peer_nonce, 0, WPA_NONCE_LEN);
mesh_rsn_derive_aek(wpa_s->mesh_rsn, sta);
}
/* insert AMPE and encrypted MIC at @ie.
* @mesh_rsn: mesh RSN context
* @sta: STA we're sending to
* @cat: pointer to category code in frame header.
* @buf: wpabuf to add encrypted AMPE and MIC to.
* */
int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta,
const u8 *cat, struct wpabuf *buf)
{
struct ieee80211_ampe_ie *ampe;
u8 const *ie = wpabuf_head_u8(buf) + wpabuf_len(buf);
u8 *ampe_ie, *pos, *mic_payload;
const u8 *aad[] = { rsn->wpa_s->own_addr, sta->addr, cat };
const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, ie - cat };
int ret = 0;
size_t len;
len = sizeof(*ampe);
if (cat[1] == PLINK_OPEN)
len += rsn->mgtk_len + WPA_KEY_RSC_LEN + 4;
if (cat[1] == PLINK_OPEN && rsn->igtk_len)
len += 2 + 6 + rsn->igtk_len;
if (2 + AES_BLOCK_SIZE + 2 + len > wpabuf_tailroom(buf)) {
wpa_printf(MSG_ERROR, "protect frame: buffer too small");
return -EINVAL;
}
ampe_ie = os_zalloc(2 + len);
if (!ampe_ie) {
wpa_printf(MSG_ERROR, "protect frame: out of memory");
return -ENOMEM;
}
/* IE: AMPE */
ampe_ie[0] = WLAN_EID_AMPE;
ampe_ie[1] = len;
ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2);
RSN_SELECTOR_PUT(ampe->selected_pairwise_suite,
RSN_CIPHER_SUITE_CCMP);
os_memcpy(ampe->local_nonce, sta->my_nonce, WPA_NONCE_LEN);
os_memcpy(ampe->peer_nonce, sta->peer_nonce, WPA_NONCE_LEN);
pos = (u8 *) (ampe + 1);
if (cat[1] != PLINK_OPEN)
goto skip_keys;
/* TODO: Key Replay Counter[8] optionally for
* Mesh Group Key Inform/Acknowledge frames */
/* TODO: static mgtk for now since we don't support rekeying! */
/*
* GTKdata[variable]:
* MGTK[variable] || Key RSC[8] || GTKExpirationTime[4]
*/
os_memcpy(pos, rsn->mgtk, rsn->mgtk_len);
pos += rsn->mgtk_len;
wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->mgtk_key_id, pos);
pos += WPA_KEY_RSC_LEN;
/* Use fixed GTKExpirationTime for now */
WPA_PUT_LE32(pos, 0xffffffff);
pos += 4;
/*
* IGTKdata[variable]:
* Key ID[2], IPN[6], IGTK[variable]
*/
if (rsn->igtk_len) {
WPA_PUT_LE16(pos, rsn->igtk_key_id);
pos += 2;
wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->igtk_key_id, pos);
pos += 6;
os_memcpy(pos, rsn->igtk, rsn->igtk_len);
}
skip_keys:
wpa_hexdump_key(MSG_DEBUG, "mesh: Plaintext AMPE element",
ampe_ie, 2 + len);
/* IE: MIC */
wpabuf_put_u8(buf, WLAN_EID_MIC);
wpabuf_put_u8(buf, AES_BLOCK_SIZE);
/* MIC field is output ciphertext */
/* encrypt after MIC */
mic_payload = wpabuf_put(buf, 2 + len + AES_BLOCK_SIZE);
if (aes_siv_encrypt(sta->aek, sizeof(sta->aek), ampe_ie, 2 + len, 3,
aad, aad_len, mic_payload)) {
wpa_printf(MSG_ERROR, "protect frame: failed to encrypt");
ret = -ENOMEM;
}
os_free(ampe_ie);
return ret;
}
int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta,
struct ieee802_11_elems *elems, const u8 *cat,
const u8 *chosen_pmk,
const u8 *start, size_t elems_len)
{
int ret = 0;
struct ieee80211_ampe_ie *ampe;
u8 null_nonce[WPA_NONCE_LEN] = {};
u8 ampe_eid;
u8 ampe_ie_len;
u8 *ampe_buf, *crypt = NULL, *pos, *end;
size_t crypt_len;
const u8 *aad[] = { sta->addr, wpa_s->own_addr, cat };
const size_t aad_len[] = { ETH_ALEN, ETH_ALEN,
elems->mic ? (elems->mic - 2) - cat : 0 };
size_t key_len;
if (!sta->sae) {
struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
if (!wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL)) {
wpa_printf(MSG_INFO,
"Mesh RSN: SAE is not prepared yet");
return -1;
}
mesh_rsn_auth_sae_sta(wpa_s, sta);
}
if (chosen_pmk &&
(!sta->sae ||
os_memcmp(chosen_pmk, sta->sae->pmkid, PMKID_LEN) != 0)) {
wpa_msg(wpa_s, MSG_DEBUG,
"Mesh RSN: Invalid PMKID (Chosen PMK did not match calculated PMKID)");
return -1;
}
if (!elems->mic || elems->mic_len < AES_BLOCK_SIZE) {
wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing mic ie");
return -1;
}
ampe_buf = (u8 *) elems->mic + elems->mic_len;
if ((int) elems_len < ampe_buf - start)
return -1;
crypt_len = elems_len - (elems->mic - start);
if (crypt_len < 2 + AES_BLOCK_SIZE) {
wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing ampe ie");
return -1;
}
/* crypt is modified by siv_decrypt */
crypt = os_zalloc(crypt_len);
if (!crypt) {
wpa_printf(MSG_ERROR, "Mesh RSN: out of memory");
ret = -ENOMEM;
goto free;
}
os_memcpy(crypt, elems->mic, crypt_len);
if (aes_siv_decrypt(sta->aek, sizeof(sta->aek), crypt, crypt_len, 3,
aad, aad_len, ampe_buf)) {
wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!");
ret = -2;
goto free;
}
crypt_len -= AES_BLOCK_SIZE;
wpa_hexdump_key(MSG_DEBUG, "mesh: Decrypted AMPE element",
ampe_buf, crypt_len);
ampe_eid = *ampe_buf++;
ampe_ie_len = *ampe_buf++;
if (ampe_eid != WLAN_EID_AMPE ||
(size_t) 2 + ampe_ie_len > crypt_len ||
ampe_ie_len < sizeof(struct ieee80211_ampe_ie)) {
wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid ampe ie");
ret = -1;
goto free;
}
ampe = (struct ieee80211_ampe_ie *) ampe_buf;
pos = (u8 *) (ampe + 1);
end = ampe_buf + ampe_ie_len;
if (os_memcmp(ampe->peer_nonce, null_nonce, WPA_NONCE_LEN) != 0 &&
os_memcmp(ampe->peer_nonce, sta->my_nonce, WPA_NONCE_LEN) != 0) {
wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid peer nonce");
ret = -1;
goto free;
}
os_memcpy(sta->peer_nonce, ampe->local_nonce,
sizeof(ampe->local_nonce));
/* TODO: Key Replay Counter[8] in Mesh Group Key Inform/Acknowledge
* frames */
/*
* GTKdata shall not be included in Mesh Peering Confirm. While the
* standard does not state the same about IGTKdata, that same constraint
* needs to apply for it. It makes no sense to include the keys in Mesh
* Peering Close frames either, so while the standard does not seem to
* have a shall statement for these, they are described without
* mentioning GTKdata.
*
* An earlier implementation used to add GTKdata to both Mesh Peering
* Open and Mesh Peering Confirm frames, so ignore the possibly present
* GTKdata frame without rejecting the frame as a backwards
* compatibility mechanism.
*/
if (cat[1] != PLINK_OPEN) {
if (end > pos) {
wpa_hexdump_key(MSG_DEBUG,
"mesh: Ignore unexpected GTKdata(etc.) fields in the end of AMPE element in Mesh Peering Confirm/Close",
pos, end - pos);
}
goto free;
}
/*
* GTKdata[variable]:
* MGTK[variable] || Key RSC[8] || GTKExpirationTime[4]
*/
sta->mgtk_key_id = 1; /* FIX: Where to get Key ID? */
key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->group_cipher);
if ((int) key_len + WPA_KEY_RSC_LEN + 4 > end - pos) {
wpa_dbg(wpa_s, MSG_DEBUG, "mesh: Truncated AMPE element");
ret = -1;
goto free;
}
sta->mgtk_len = key_len;
os_memcpy(sta->mgtk, pos, sta->mgtk_len);
wpa_hexdump_key(MSG_DEBUG, "mesh: GTKdata - MGTK",
sta->mgtk, sta->mgtk_len);
pos += sta->mgtk_len;
wpa_hexdump(MSG_DEBUG, "mesh: GTKdata - MGTK - Key RSC",
pos, WPA_KEY_RSC_LEN);
os_memcpy(sta->mgtk_rsc, pos, sizeof(sta->mgtk_rsc));
pos += WPA_KEY_RSC_LEN;
wpa_printf(MSG_DEBUG,
"mesh: GTKdata - MGTK - GTKExpirationTime: %u seconds",
WPA_GET_LE32(pos));
pos += 4;
/*
* IGTKdata[variable]:
* Key ID[2], IPN[6], IGTK[variable]
*/
key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->mgmt_group_cipher);
if (end - pos >= (int) (2 + 6 + key_len)) {
sta->igtk_key_id = WPA_GET_LE16(pos);
wpa_printf(MSG_DEBUG, "mesh: IGTKdata - Key ID %u",
sta->igtk_key_id);
pos += 2;
os_memcpy(sta->igtk_rsc, pos, sizeof(sta->igtk_rsc));
wpa_hexdump(MSG_DEBUG, "mesh: IGTKdata - IPN",
sta->igtk_rsc, sizeof(sta->igtk_rsc));
pos += 6;
os_memcpy(sta->igtk, pos, key_len);
sta->igtk_len = key_len;
wpa_hexdump_key(MSG_DEBUG, "mesh: IGTKdata - IGTK",
sta->igtk, sta->igtk_len);
}
free:
os_free(crypt);
return ret;
}