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mesh: Add mesh robust security network

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This implementation provides:

- Mesh SAE authentication mechanism
- Key management (set/get PSK)
- Cryptographic key establishment
- Enhanced protection mechanisms for robust management frames

Signed-off-by: Javier Lopez <jlopex@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Jason Mobarak <x@jason.mobarak.name>
Signed-off-by: Thomas Pedersen <thomas@noack.us>
This commit is contained in:
Thomas Pedersen 2014-09-01 00:23:29 -04:00 committed by Jouni Malinen
parent 88cb27c7a5
commit 0f950df029
9 changed files with 692 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
src/ap/sta_info.h
View file

@ -61,6 +61,11 @@ struct sta_info {
u16 my_lid;
u16 mpm_close_reason;
int mpm_retries;
u8 my_nonce[32];
u8 peer_nonce[32];
u8 aek[32]; /* SHA256 digest length */
u8 mtk[16];
u8 mgtk[16];
#endif /* CONFIG_MESH */
unsigned int nonerp_set:1;

3
src/ap/wpa_auth.h
View file

@ -213,6 +213,9 @@ struct wpa_auth_callbacks {
int (*add_tspec)(void *ctx, const u8 *sta_addr, u8 *tspec_ie,
size_t tspec_ielen);
#endif /* CONFIG_IEEE80211R */
#ifdef CONFIG_MESH
int (*start_ampe)(void *ctx, const u8 *sta_addr);
#endif /* CONFIG_MESH */
};
struct wpa_authenticator * wpa_init(const u8 *addr,

7
wpa_supplicant/Android.mk
View file

@ -203,9 +203,16 @@ endif
ifdef CONFIG_MESH
NEED_80211_COMMON=y
NEED_SHA256=y
NEED_AES_SIV=y
NEED_AES_OMAC1=y
NEED_AES_CTR=y
CONFIG_SAE=y
CONFIG_AP=y
L_CFLAGS += -DCONFIG_MESH
OBJS += mesh.c
OBJS += mesh_mpm.c
OBJS += mesh_rsn.c
endif
ifdef CONFIG_SAE

7
wpa_supplicant/Makefile
View file

@ -206,9 +206,16 @@ endif
ifdef CONFIG_MESH
NEED_80211_COMMON=y
NEED_SHA256=y
NEED_AES_SIV=y
NEED_AES_OMAC1=y
NEED_AES_CTR=y
CONFIG_SAE=y
CONFIG_AP=y
CFLAGS += -DCONFIG_MESH
OBJS += mesh.o
OBJS += mesh_mpm.o
OBJS += mesh_rsn.o
endif
ifdef CONFIG_SAE

7
wpa_supplicant/mesh.c
View file

@ -22,6 +22,7 @@
#include "driver_i.h"
#include "notify.h"
#include "mesh_mpm.h"
#include "mesh_rsn.h"
#include "mesh.h"
@ -30,6 +31,8 @@ static void wpa_supplicant_mesh_deinit(struct wpa_supplicant *wpa_s)
wpa_supplicant_mesh_iface_deinit(wpa_s, wpa_s->ifmsh);
wpa_s->ifmsh = NULL;
wpa_s->current_ssid = NULL;
os_free(wpa_s->mesh_rsn);
wpa_s->mesh_rsn = NULL;
/* TODO: leave mesh (stop beacon). This will happen on link down
* anyway, so it's not urgent */
}
@ -231,6 +234,10 @@ static int wpa_supplicant_mesh_init(struct wpa_supplicant *wpa_s,
len = os_strlen(ssid->passphrase);
bss->conf->ssid.wpa_passphrase =
dup_binstr(ssid->passphrase, len);
wpa_s->mesh_rsn = mesh_rsn_auth_init(wpa_s, mconf);
if (!wpa_s->mesh_rsn)
goto out_free;
}
return 0;

52
wpa_supplicant/mesh_mpm.c
View file

@ -17,6 +17,7 @@
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "mesh_mpm.h"
#include "mesh_rsn.h"
/* TODO make configurable */
#define dot11MeshMaxRetries 10
@ -212,7 +213,7 @@ static void mesh_mpm_send_plink_action(struct wpa_supplicant *wpa_s,
struct hostapd_data *bss = ifmsh->bss[0];
struct mesh_conf *conf = ifmsh->mconf;
u8 supp_rates[2 + 2 + 32];
u8 *pos;
u8 *pos, *cat;
u8 ie_len, add_plid = 0;
int ret;
int ampe = conf->security & MESH_CONF_SEC_AMPE;
@ -234,6 +235,7 @@ static void mesh_mpm_send_plink_action(struct wpa_supplicant *wpa_s,
if (!buf)
return;
cat = wpabuf_mhead_u8(buf);
wpabuf_put_u8(buf, WLAN_ACTION_SELF_PROTECTED);
wpabuf_put_u8(buf, type);
@ -303,9 +305,18 @@ static void mesh_mpm_send_plink_action(struct wpa_supplicant *wpa_s,
wpabuf_put_le16(buf, sta->peer_lid);
if (type == PLINK_CLOSE)
wpabuf_put_le16(buf, close_reason);
if (ampe)
mesh_rsn_get_pmkid(wpa_s->mesh_rsn, sta,
wpabuf_put(buf, PMKID_LEN));
/* TODO HT IEs */
if (ampe && mesh_rsn_protect_frame(wpa_s->mesh_rsn, sta, cat, buf)) {
wpa_msg(wpa_s, MSG_INFO,
"Mesh MPM: failed to add AMPE and MIC IE");
goto fail;
}
ret = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0,
sta->addr, wpa_s->own_addr, wpa_s->own_addr,
wpabuf_head(buf), wpabuf_len(buf), 0);
@ -313,6 +324,7 @@ static void mesh_mpm_send_plink_action(struct wpa_supplicant *wpa_s,
wpa_msg(wpa_s, MSG_INFO,
"Mesh MPM: failed to send peering frame");
fail:
wpabuf_free(buf);
}
@ -462,6 +474,8 @@ void mesh_mpm_auth_peer(struct wpa_supplicant *wpa_s, const u8 *addr)
* the AP code already sets this flag. */
sta->flags |= WLAN_STA_AUTH;
mesh_rsn_init_ampe_sta(wpa_s, sta);
os_memset(&params, 0, sizeof(params));
params.addr = sta->addr;
params.flags = WPA_STA_AUTHENTICATED | WPA_STA_AUTHORIZED;
@ -539,7 +553,10 @@ void wpa_mesh_new_mesh_peer(struct wpa_supplicant *wpa_s, const u8 *addr,
return;
}
if (conf->security == MESH_CONF_SEC_NONE)
mesh_mpm_plink_open(wpa_s, sta, PLINK_OPEN_SENT);
else
mesh_rsn_auth_sae_sta(wpa_s, sta);
}
@ -559,10 +576,27 @@ static void mesh_mpm_plink_estab(struct wpa_supplicant *wpa_s,
struct sta_info *sta)
{
struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
struct mesh_conf *conf = wpa_s->ifmsh->mconf;
u8 seq[6] = {};
wpa_msg(wpa_s, MSG_INFO, "mesh plink with " MACSTR " established",
MAC2STR(sta->addr));
if (conf->security & MESH_CONF_SEC_AMPE) {
wpa_drv_set_key(wpa_s, WPA_ALG_CCMP, sta->addr, 0, 0,
seq, sizeof(seq), sta->mtk, sizeof(sta->mtk));
wpa_drv_set_key(wpa_s, WPA_ALG_CCMP, sta->addr, 1, 0,
seq, sizeof(seq),
sta->mgtk, sizeof(sta->mgtk));
wpa_drv_set_key(wpa_s, WPA_ALG_IGTK, sta->addr, 4, 0,
seq, sizeof(seq),
sta->mgtk, sizeof(sta->mgtk));
wpa_hexdump_key(MSG_DEBUG, "mtk:", sta->mtk, sizeof(sta->mtk));
wpa_hexdump_key(MSG_DEBUG, "mgtk:",
sta->mgtk, sizeof(sta->mgtk));
}
wpa_mesh_set_plink_state(wpa_s, sta, PLINK_ESTAB);
hapd->num_plinks++;
@ -580,6 +614,7 @@ static void mesh_mpm_fsm(struct wpa_supplicant *wpa_s, struct sta_info *sta,
enum plink_event event)
{
struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
struct mesh_conf *conf = wpa_s->ifmsh->mconf;
u16 reason = 0;
wpa_msg(wpa_s, MSG_DEBUG, "MPM " MACSTR " state %s event %s",
@ -652,6 +687,8 @@ static void mesh_mpm_fsm(struct wpa_supplicant *wpa_s, struct sta_info *sta,
PLINK_CONFIRM, 0);
break;
case CNF_ACPT:
if (conf->security & MESH_CONF_SEC_AMPE)
mesh_rsn_derive_mtk(wpa_s, sta);
mesh_mpm_plink_estab(wpa_s, sta);
break;
default:
@ -745,6 +782,7 @@ void mesh_mpm_action_rx(struct wpa_supplicant *wpa_s,
{
u8 action_field;
struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
struct mesh_conf *mconf = wpa_s->ifmsh->mconf;
struct sta_info *sta;
u16 plid = 0, llid = 0;
enum plink_event event;
@ -804,9 +842,21 @@ void mesh_mpm_action_rx(struct wpa_supplicant *wpa_s,
if (!sta)
return;
#ifdef CONFIG_SAE
/* peer is in sae_accepted? */
if (sta->sae && sta->sae->state != SAE_ACCEPTED)
return;
#endif /* CONFIG_SAE */
if (!sta->my_lid)
mesh_mpm_init_link(wpa_s, sta);
if (mconf->security & MESH_CONF_SEC_AMPE)
if (mesh_rsn_process_ampe(wpa_s, sta, &elems,
&mgmt->u.action.category,
ies, ie_len))
return;
if (sta->plink_state == PLINK_BLOCKED)
return;

573
wpa_supplicant/mesh_rsn.c Normal file
View file

@ -0,0 +1,573 @@
/*
* 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 "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 "wpa_supplicant_i.h"
#include "driver_i.h"
#include "wpas_glue.h"
#include "mesh_mpm.h"
#include "mesh_rsn.h"
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)
{
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);
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;
if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH)
return -1;
mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr);
return 0;
}
static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr)
{
struct wpa_auth_config conf;
struct wpa_auth_callbacks cb;
u8 seq[6] = {};
wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
os_memset(&conf, 0, sizeof(conf));
conf.wpa = 2;
conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE;
conf.wpa_pairwise = WPA_CIPHER_CCMP;
conf.rsn_pairwise = WPA_CIPHER_CCMP;
conf.wpa_group = WPA_CIPHER_CCMP;
conf.eapol_version = 0;
conf.wpa_group_rekey = -1;
os_memset(&cb, 0, sizeof(cb));
cb.ctx = rsn;
cb.logger = auth_logger;
cb.get_psk = auth_get_psk;
cb.set_key = auth_set_key;
cb.start_ampe = auth_start_ampe;
rsn->auth = wpa_init(addr, &conf, &cb);
if (rsn->auth == NULL) {
wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
return -1;
}
/* TODO: support rekeying */
if (random_get_bytes(rsn->mgtk, 16) < 0) {
wpa_deinit(rsn->auth);
return -1;
}
/* group mgmt */
wpa_drv_set_key(rsn->wpa_s, WPA_ALG_IGTK, NULL, 4, 1,
seq, sizeof(seq), rsn->mgtk, sizeof(rsn->mgtk));
/* group privacy / data frames */
wpa_drv_set_key(rsn->wpa_s, WPA_ALG_CCMP, NULL, 1, 1,
seq, sizeof(seq), rsn->mgtk, sizeof(rsn->mgtk));
return 0;
}
static void mesh_rsn_deinit(struct mesh_rsn *rsn)
{
os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk));
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;
mesh_rsn = os_zalloc(sizeof(*mesh_rsn));
if (mesh_rsn == NULL)
return NULL;
mesh_rsn->wpa_s = wpa_s;
if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr) < 0) {
mesh_rsn_deinit(mesh_rsn);
return NULL;
}
bss->wpa_auth = mesh_rsn->auth;
ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len);
conf->ies = (u8 *) ie;
conf->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;
}
struct wpabuf *
mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s,
struct wpa_ssid *ssid, struct sta_info *sta)
{
struct wpabuf *buf;
int len;
if (ssid->passphrase == NULL) {
wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available");
return NULL;
}
if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) {
wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group");
return NULL;
}
if (sae_prepare_commit(wpa_s->own_addr, sta->addr,
(u8 *) ssid->passphrase,
os_strlen(ssid->passphrase), sta->sae) < 0) {
wpa_msg(wpa_s, MSG_DEBUG, "SAE: Could not pick PWE");
return NULL;
}
len = wpa_s->mesh_rsn->sae_token ?
wpabuf_len(wpa_s->mesh_rsn->sae_token) : 0;
buf = wpabuf_alloc(4 + SAE_COMMIT_MAX_LEN + len);
if (buf == NULL)
return NULL;
sae_write_commit(sta->sae, buf, wpa_s->mesh_rsn->sae_token);
return buf;
}
static void mesh_rsn_send_auth(struct wpa_supplicant *wpa_s,
const u8 *dst, const u8 *src,
u16 auth_transaction, u16 resp,
struct wpabuf *data)
{
struct ieee80211_mgmt *auth;
u8 *buf;
size_t len, ielen = 0;
if (data)
ielen = wpabuf_len(data);
len = IEEE80211_HDRLEN + sizeof(auth->u.auth) + ielen;
buf = os_zalloc(len);
if (buf == NULL)
return;
auth = (struct ieee80211_mgmt *) buf;
auth->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
WLAN_FC_STYPE_AUTH);
os_memcpy(auth->da, dst, ETH_ALEN);
os_memcpy(auth->sa, src, ETH_ALEN);
os_memcpy(auth->bssid, src, ETH_ALEN);
auth->u.auth.auth_alg = host_to_le16(WLAN_AUTH_SAE);
auth->u.auth.auth_transaction = host_to_le16(auth_transaction);
auth->u.auth.status_code = host_to_le16(resp);
if (data)
os_memcpy(auth->u.auth.variable, wpabuf_head(data), ielen);
wpa_msg(wpa_s, MSG_DEBUG, "authentication frame: STA=" MACSTR
" auth_transaction=%d resp=%d (IE len=%lu)",
MAC2STR(dst), auth_transaction, resp, (unsigned long) ielen);
if (wpa_drv_send_mlme(wpa_s, buf, len, 0) < 0)
perror("send_auth_reply: send");
os_free(buf);
}
/* initiate new SAE authentication with sta */
int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s,
struct sta_info *sta)
{
struct wpa_ssid *ssid = wpa_s->current_ssid;
struct wpabuf *buf;
if (!sta->sae) {
sta->sae = os_zalloc(sizeof(*sta->sae));
if (sta->sae == NULL)
return -1;
}
buf = mesh_rsn_build_sae_commit(wpa_s, ssid, sta);
if (!buf)
return -1;
wpa_msg(wpa_s, MSG_DEBUG,
"AUTH: started authentication with SAE peer: " MACSTR,
MAC2STR(sta->addr));
sta->sae->state = SAE_COMMITTED;
wpa_supplicant_set_state(wpa_s, WPA_AUTHENTICATING);
mesh_rsn_send_auth(wpa_s, sta->addr, wpa_s->own_addr,
1, WLAN_STATUS_SUCCESS, buf);
wpabuf_free(buf);
return 0;
}
void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid)
{
/* don't expect wpa auth to cache the pmkid for now */
rsn_pmkid(sta->sae->pmk, PMK_LEN, rsn->wpa_s->own_addr,
sta->addr, pmkid,
wpa_key_mgmt_sha256(wpa_auth_sta_key_mgmt(sta->wpa_sm)));
}
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 = peer, *addr2 = myaddr;
u8 context[AES_BLOCK_SIZE];
/* SAE */
RSN_SELECTOR_PUT(context, wpa_cipher_to_suite(0, WPA_CIPHER_GCMP));
if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
addr1 = myaddr;
addr2 = peer;
}
os_memcpy(context + 4, addr1, ETH_ALEN);
os_memcpy(context + 10, 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;
u16 min_lid, max_lid;
size_t nonce_len = sizeof(sta->my_nonce);
size_t lid_len = sizeof(sta->my_lid);
u8 *myaddr = wpa_s->own_addr;
u8 *peer = sta->addr;
/* 2 nonces, 2 linkids, akm suite, 2 mac addrs */
u8 context[64 + 4 + 4 + 12];
ptr = context;
if (os_memcmp(sta->my_nonce, sta->peer_nonce, nonce_len) < 0) {
min = sta->my_nonce;
max = sta->peer_nonce;
} else {
min = sta->peer_nonce;
max = sta->my_nonce;
}
os_memcpy(ptr, min, nonce_len);
os_memcpy(ptr + nonce_len, max, nonce_len);
ptr += 2 * nonce_len;
if (sta->my_lid < sta->peer_lid) {
min_lid = host_to_le16(sta->my_lid);
max_lid = host_to_le16(sta->peer_lid);
} else {
min_lid = host_to_le16(sta->peer_lid);
max_lid = host_to_le16(sta->my_lid);
}
os_memcpy(ptr, &min_lid, lid_len);
os_memcpy(ptr + lid_len, &max_lid, lid_len);
ptr += 2 * lid_len;
/* SAE */
RSN_SELECTOR_PUT(ptr, wpa_cipher_to_suite(0, WPA_CIPHER_GCMP));
ptr += 4;
if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
min = myaddr;
max = peer;
} else {
min = peer;
max = myaddr;
}
os_memcpy(ptr, min, ETH_ALEN);
os_memcpy(ptr + ETH_ALEN, max, ETH_ALEN);
sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk),
"Temporal Key Derivation", context, sizeof(context),
sta->mtk, sizeof(sta->mtk));
return 0;
}
void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta)
{
if (random_get_bytes(sta->my_nonce, 32) < 0) {
wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce");
/* TODO: How to handle this more cleanly? */
}
os_memset(sta->peer_nonce, 0, 32);
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 = NULL, *mic_ie = NULL, *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;
if (AES_BLOCK_SIZE + 2 + sizeof(*ampe) + 2 > wpabuf_tailroom(buf)) {
wpa_printf(MSG_ERROR, "protect frame: buffer too small");
return -EINVAL;
}
ampe_ie = os_zalloc(2 + sizeof(*ampe));
if (!ampe_ie) {
wpa_printf(MSG_ERROR, "protect frame: out of memory");
return -ENOMEM;
}
mic_ie = os_zalloc(2 + AES_BLOCK_SIZE);
if (!mic_ie) {
wpa_printf(MSG_ERROR, "protect frame: out of memory");
ret = -ENOMEM;
goto free;
}
/* IE: AMPE */
ampe_ie[0] = WLAN_EID_AMPE;
ampe_ie[1] = sizeof(*ampe);
ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2);
RSN_SELECTOR_PUT(ampe->selected_pairwise_suite,
wpa_cipher_to_suite(WPA_PROTO_RSN, WPA_CIPHER_CCMP));
os_memcpy(ampe->local_nonce, sta->my_nonce, 32);
os_memcpy(ampe->peer_nonce, sta->peer_nonce, 32);
/* incomplete: see 13.5.4 */
/* TODO: static mgtk for now since we don't support rekeying! */
os_memcpy(ampe->mgtk, rsn->mgtk, 16);
/* TODO: Populate Key RSC */
/* expire in 13 decades or so */
os_memset(ampe->key_expiration, 0xff, 4);
/* IE: MIC */
mic_ie[0] = WLAN_EID_MIC;
mic_ie[1] = AES_BLOCK_SIZE;
wpabuf_put_data(buf, mic_ie, 2);
/* MIC field is output ciphertext */
/* encrypt after MIC */
mic_payload = (u8 *) wpabuf_put(buf, 2 + sizeof(*ampe) +
AES_BLOCK_SIZE);
if (aes_siv_encrypt(sta->aek, ampe_ie, 2 + sizeof(*ampe), 3,
aad, aad_len, mic_payload)) {
wpa_printf(MSG_ERROR, "protect frame: failed to encrypt");
ret = -ENOMEM;
goto free;
}
free:
os_free(ampe_ie);
os_free(mic_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 *start, size_t elems_len)
{
int ret = 0;
struct ieee80211_ampe_ie *ampe;
u8 null_nonce[32] = {};
u8 ampe_eid;
u8 ampe_ie_len;
u8 *ampe_buf, *crypt = NULL;
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 - 2) - cat };
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) {
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, crypt, crypt_len, 3,
aad, aad_len, ampe_buf)) {
wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!");
ret = -1;
goto free;
}
ampe_eid = *ampe_buf++;
ampe_ie_len = *ampe_buf++;
if (ampe_eid != WLAN_EID_AMPE ||
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;
if (os_memcmp(ampe->peer_nonce, null_nonce, 32) != 0 &&
os_memcmp(ampe->peer_nonce, sta->my_nonce, 32) != 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));
os_memcpy(sta->mgtk, ampe->mgtk, sizeof(ampe->mgtk));
/* todo parse mgtk expiration */
free:
os_free(crypt);
return ret;
}

35
wpa_supplicant/mesh_rsn.h Normal file
View file

@ -0,0 +1,35 @@
/*
* 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.
*/
#ifndef MESH_RSN_H
#define MESH_RSN_H
struct mesh_rsn {
struct wpa_supplicant *wpa_s;
struct wpa_authenticator *auth;
u8 mgtk[16];
#ifdef CONFIG_SAE
struct wpabuf *sae_token;
int sae_group_index;
#endif /* CONFIG_SAE */
};
struct mesh_rsn * mesh_rsn_auth_init(struct wpa_supplicant *wpa_s,
struct mesh_conf *conf);
int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta);
int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta);
void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid);
void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s,
struct sta_info *sta);
int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta,
const u8 *cat, struct wpabuf *buf);
int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta,
struct ieee802_11_elems *elems, const u8 *cat,
const u8 *start, size_t elems_len);
#endif /* MESH_RSN_H */

3
wpa_supplicant/wpa_supplicant_i.h
View file

@ -668,6 +668,9 @@ struct wpa_supplicant {
#endif /* CONFIG_AP */
struct hostapd_iface *ifmsh;
#ifdef CONFIG_MESH
struct mesh_rsn *mesh_rsn;
#endif /* CONFIG_MESH */
unsigned int off_channel_freq;
struct wpabuf *pending_action_tx;