jeltz/hostap
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Fix TK configuration to the driver in EAPOL-Key 3/4 retry case

Browse source 
Commit 7d711541dc ('Clear TK part of PTK
after driver key configuration') started clearing TK from memory
immediately after having configured it to the driver when processing
EAPOL-Key message 3/4. While this covered the most common case, it did
not take into account the possibility of the authenticator having to
retry EAPOL-Key message 3/4 in case the first EAPOL-Key message 4/4
response is lost. That case ended up trying to reinstall the same TK to
the driver, but the key was not available anymore.

Fix the EAPOL-Key message 3/4 retry case by configuring TK to the driver
only once. There was no need to try to set the same key after each
EAPOL-Key message 3/4 since TK could not change. If actual PTK rekeying
is used, the new TK will be configured once when processing the new
EAPOL-Key message 3/4 for the first time.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2015-10-01 18:51:04 +03:00 committed by Jouni Malinen
parent 60bfe7061d
commit ad00d64e7d
2 changed files with 9 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
src/rsn_supp/wpa.c
View file

@ -500,6 +500,7 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
os_memset(buf, 0, sizeof(buf));
}
sm->tptk_set = 1;
sm->tk_to_set = 1;
kde = sm->assoc_wpa_ie;
kde_len = sm->assoc_wpa_ie_len;
@ -605,6 +606,12 @@ static int wpa_supplicant_install_ptk(struct wpa_sm *sm,
const u8 *key_rsc;
u8 null_rsc[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
if (!sm->tk_to_set) {
wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG,
"WPA: Do not re-install same PTK to the driver");
return 0;
}
wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG,
"WPA: Installing PTK to the driver");
@ -643,6 +650,7 @@ static int wpa_supplicant_install_ptk(struct wpa_sm *sm,
/* TK is not needed anymore in supplicant */
os_memset(sm->ptk.tk, 0, WPA_TK_MAX_LEN);
sm->tk_to_set = 0;
if (sm->wpa_ptk_rekey) {
eloop_cancel_timeout(wpa_sm_rekey_ptk, sm, NULL);

1
src/rsn_supp/wpa_i.h
View file

@ -24,6 +24,7 @@ struct wpa_sm {
struct wpa_ptk ptk, tptk;
int ptk_set, tptk_set;
unsigned int msg_3_of_4_ok:1;
unsigned int tk_to_set:1;
u8 snonce[WPA_NONCE_LEN];
u8 anonce[WPA_NONCE_LEN]; /* ANonce from the last 1/4 msg */
int renew_snonce;