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FT: Do not expose GTK/IGTK in FT Reassociation Response frame in OSEN

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Do not include the actual GTK/IGTK value in FT protocol cases in OSEN or
with DGAF disabled (Hotspot 2.0). This was already the case for the
EAPOL-Key cases of providing GTK/IGTK, but the FT protocol case was
missed. OSEN cannot really use FT, so that part is not impacted, but it
would be possible to enable FT in a Hotspot 2.0 network that has DGAF
disabled.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
This commit is contained in:
Jouni Malinen 2020-05-29 21:23:09 +03:00 committed by Jouni Malinen
parent a998337895
commit 2d6cc0e670
1 changed files with 37 additions and 5 deletions
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42
src/ap/wpa_auth_ft.c
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@ -2163,11 +2163,12 @@ static inline int wpa_auth_get_seqnum(struct wpa_authenticator *wpa_auth,
static u8 * wpa_ft_gtk_subelem(struct wpa_state_machine *sm, size_t *len) static u8 * wpa_ft_gtk_subelem(struct wpa_state_machine *sm, size_t *len)
{ {
u8 *subelem; u8 *subelem;
struct wpa_auth_config *conf = &sm->wpa_auth->conf;
struct wpa_group *gsm = sm->group; struct wpa_group *gsm = sm->group;
size_t subelem_len, pad_len; size_t subelem_len, pad_len;
const u8 *key; const u8 *key;
size_t key_len; size_t key_len;
u8 keybuf[32]; u8 keybuf[WPA_GTK_MAX_LEN];
const u8 *kek; const u8 *kek;
size_t kek_len; size_t kek_len;
@ -2194,12 +2195,30 @@ static u8 * wpa_ft_gtk_subelem(struct wpa_state_machine *sm, size_t *len)
pad_len += 8; pad_len += 8;
if (pad_len && key_len < sizeof(keybuf)) { if (pad_len && key_len < sizeof(keybuf)) {
os_memcpy(keybuf, gsm->GTK[gsm->GN - 1], key_len); os_memcpy(keybuf, gsm->GTK[gsm->GN - 1], key_len);
if (conf->disable_gtk ||
sm->wpa_key_mgmt == WPA_KEY_MGMT_OSEN) {
/*
* Provide unique random GTK to each STA to prevent use
* of GTK in the BSS.
*/
if (random_get_bytes(keybuf, key_len) < 0)
return NULL;
}
os_memset(keybuf + key_len, 0, pad_len); os_memset(keybuf + key_len, 0, pad_len);
keybuf[key_len] = 0xdd; keybuf[key_len] = 0xdd;
key_len += pad_len; key_len += pad_len;
key = keybuf; key = keybuf;
} else } else if (conf->disable_gtk || sm->wpa_key_mgmt == WPA_KEY_MGMT_OSEN) {
/*
* Provide unique random GTK to each STA to prevent use of GTK
* in the BSS.
*/
if (random_get_bytes(keybuf, key_len) < 0)
return NULL;
key = keybuf;
} else {
key = gsm->GTK[gsm->GN - 1]; key = gsm->GTK[gsm->GN - 1];
}
/* /*
* Sub-elem ID[1] | Length[1] | Key Info[2] | Key Length[1] | RSC[8] | * Sub-elem ID[1] | Length[1] | Key Info[2] | Key Length[1] | RSC[8] |
@ -2233,11 +2252,13 @@ static u8 * wpa_ft_gtk_subelem(struct wpa_state_machine *sm, size_t *len)
static u8 * wpa_ft_igtk_subelem(struct wpa_state_machine *sm, size_t *len) static u8 * wpa_ft_igtk_subelem(struct wpa_state_machine *sm, size_t *len)
{ {
u8 *subelem, *pos; u8 *subelem, *pos;
struct wpa_auth_config *conf = &sm->wpa_auth->conf;
struct wpa_group *gsm = sm->group; struct wpa_group *gsm = sm->group;
size_t subelem_len; size_t subelem_len;
const u8 *kek; const u8 *kek, *igtk;
size_t kek_len; size_t kek_len;
size_t igtk_len; size_t igtk_len;
u8 dummy_igtk[WPA_IGTK_MAX_LEN];
if (wpa_key_mgmt_fils(sm->wpa_key_mgmt)) { if (wpa_key_mgmt_fils(sm->wpa_key_mgmt)) {
kek = sm->PTK.kek2; kek = sm->PTK.kek2;
@ -2264,8 +2285,19 @@ static u8 * wpa_ft_igtk_subelem(struct wpa_state_machine *sm, size_t *len)
wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN_igtk, pos); wpa_auth_get_seqnum(sm->wpa_auth, NULL, gsm->GN_igtk, pos);
pos += 6; pos += 6;
*pos++ = igtk_len; *pos++ = igtk_len;
if (aes_wrap(kek, kek_len, igtk_len / 8, igtk = gsm->IGTK[gsm->GN_igtk - 4];
gsm->IGTK[gsm->GN_igtk - 4], pos)) { if (conf->disable_gtk || sm->wpa_key_mgmt == WPA_KEY_MGMT_OSEN) {
/*
* Provide unique random IGTK to each STA to prevent use of
* IGTK in the BSS.
*/
if (random_get_bytes(dummy_igtk, igtk_len / 8) < 0) {
os_free(subelem);
return NULL;
}
igtk = dummy_igtk;
}
if (aes_wrap(kek, kek_len, igtk_len / 8, igtk, pos)) {
wpa_printf(MSG_DEBUG, wpa_printf(MSG_DEBUG,
"FT: IGTK subelem encryption failed: kek_len=%d", "FT: IGTK subelem encryption failed: kek_len=%d",
(int) kek_len); (int) kek_len);