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wlantest: Fix handling of PTK rekeying

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Use a temporary PTK buffer during 4-way handshake when rekeying PTK
so that the new EAPOL-Key frame MIC values are checked against the
new PTK and frames are decrypted using the old PTK. Take the new
PTK into use once msg 4/4 is processed and clear RSC counters at
that point (including moving of RSC update to avoid setting RSC
based on the msg 4/4).

In addition, add a workaround to handle supplicant implementations that
set Secure bit to one during PTK rekeying 4-way handshake in msg 2/4.
This was previously assumed to be msg 4/4, but the key data contents
can be used to figure out whether this is msg 2/4 even if the Secure
bit is set to one.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2011-11-14 22:33:26 +02:00 committed by Jouni Malinen
parent adc33680e3
commit d0b251d2e8
3 changed files with 56 additions and 14 deletions
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2
wlantest/rx_data.c
View file

@ -342,9 +342,9 @@ skip_replay_det:
const u8 *peer_addr = NULL;
if (!(fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)))
peer_addr = hdr->addr1;
os_memcpy(rsc, pn, 6);
rx_data_process(wt, bss->bssid, sta->addr, dst, src, decrypted,
dlen, 1, peer_addr);
os_memcpy(rsc, pn, 6);
write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
decrypted, dlen);
}

66
wlantest/rx_eapol.c
View file

@ -112,6 +112,21 @@ static int try_pmk(struct wlantest_bss *bss, struct wlantest_sta *sta,
wpa_printf(MSG_INFO, "Derived PTK for STA " MACSTR " BSSID " MACSTR,
MAC2STR(sta->addr), MAC2STR(bss->bssid));
sta->counters[WLANTEST_STA_COUNTER_PTK_LEARNED]++;
if (sta->ptk_set) {
/*
* Rekeying - use new PTK for EAPOL-Key frames, but continue
* using the old PTK for frame decryption.
*/
os_memcpy(&sta->tptk, &ptk, sizeof(ptk));
wpa_hexdump(MSG_DEBUG, "TPTK:KCK", sta->tptk.kck, 16);
wpa_hexdump(MSG_DEBUG, "TPTK:KEK", sta->tptk.kek, 16);
wpa_hexdump(MSG_DEBUG, "TPTK:TK1", sta->tptk.tk1, 16);
if (ptk_len > 48)
wpa_hexdump(MSG_DEBUG, "TPTK:TK2", sta->tptk.u.tk2,
16);
sta->tptk_set = 1;
return 0;
}
os_memcpy(&sta->ptk, &ptk, sizeof(ptk));
wpa_hexdump(MSG_DEBUG, "PTK:KCK", sta->ptk.kck, 16);
wpa_hexdump(MSG_DEBUG, "PTK:KEK", sta->ptk.kek, 16);
@ -155,7 +170,7 @@ static void rx_data_eapol_key_2_of_4(struct wlantest *wt, const u8 *dst,
struct wlantest_sta *sta;
const struct ieee802_1x_hdr *eapol;
const struct wpa_eapol_key *hdr;
const u8 *key_data;
const u8 *key_data, *kck;
u16 key_info, key_data_len;
struct wpa_eapol_ie_parse ie;
@ -183,13 +198,17 @@ static void rx_data_eapol_key_2_of_4(struct wlantest *wt, const u8 *dst,
key_data_len = WPA_GET_BE16(hdr->key_data_length);
derive_ptk(wt, bss, sta, key_info & WPA_KEY_INFO_TYPE_MASK, data, len);
if (!sta->ptk_set) {
if (!sta->ptk_set && !sta->tptk_set) {
wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 2/4");
return;
}
if (check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
data, len) < 0) {
kck = sta->ptk.kck;
if (sta->tptk_set) {
wpa_printf(MSG_DEBUG, "Use TPTK for validation EAPOL-Key MIC");
kck = sta->tptk.kck;
}
if (check_mic(kck, key_info & WPA_KEY_INFO_TYPE_MASK, data, len) < 0) {
wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 2/4 MIC");
return;
}
@ -398,7 +417,7 @@ static void rx_data_eapol_key_3_of_4(struct wlantest *wt, const u8 *dst,
struct wlantest_sta *sta;
const struct ieee802_1x_hdr *eapol;
const struct wpa_eapol_key *hdr;
const u8 *key_data;
const u8 *key_data, *kck;
int recalc = 0;
u16 key_info, ver;
u8 *decrypted_buf = NULL;
@ -430,13 +449,17 @@ static void rx_data_eapol_key_3_of_4(struct wlantest *wt, const u8 *dst,
data, len);
}
if (!sta->ptk_set) {
if (!sta->ptk_set && !sta->tptk_set) {
wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 3/4");
return;
}
if (check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
data, len) < 0) {
kck = sta->ptk.kck;
if (sta->tptk_set) {
wpa_printf(MSG_DEBUG, "Use TPTK for validation EAPOL-Key MIC");
kck = sta->tptk.kck;
}
if (check_mic(kck, key_info & WPA_KEY_INFO_TYPE_MASK, data, len) < 0) {
wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 3/4 MIC");
return;
}
@ -549,6 +572,7 @@ static void rx_data_eapol_key_4_of_4(struct wlantest *wt, const u8 *dst,
const struct ieee802_1x_hdr *eapol;
const struct wpa_eapol_key *hdr;
u16 key_info;
const u8 *kck;
wpa_printf(MSG_DEBUG, "EAPOL-Key 4/4 " MACSTR " -> " MACSTR,
MAC2STR(src), MAC2STR(dst));
@ -567,18 +591,29 @@ static void rx_data_eapol_key_4_of_4(struct wlantest *wt, const u8 *dst,
}
key_info = WPA_GET_BE16(hdr->key_info);
if (!sta->ptk_set) {
if (!sta->ptk_set && !sta->tptk_set) {
wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 4/4");
return;
}
if (sta->ptk_set &&
check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
data, len) < 0) {
kck = sta->ptk.kck;
if (sta->tptk_set) {
wpa_printf(MSG_DEBUG, "Use TPTK for validation EAPOL-Key MIC");
kck = sta->tptk.kck;
}
if (check_mic(kck, key_info & WPA_KEY_INFO_TYPE_MASK, data, len) < 0) {
wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 4/4 MIC");
return;
}
wpa_printf(MSG_DEBUG, "Valid MIC found in EAPOL-Key 4/4");
if (sta->tptk_set) {
wpa_printf(MSG_DEBUG, "Update PTK (rekeying)");
os_memcpy(&sta->ptk, &sta->tptk, sizeof(sta->ptk));
sta->ptk_set = 1;
sta->tptk_set = 0;
os_memset(sta->rsc_tods, 0, sizeof(sta->rsc_tods));
os_memset(sta->rsc_fromds, 0, sizeof(sta->rsc_fromds));
}
}
@ -907,7 +942,12 @@ static void rx_data_eapol_key(struct wlantest *wt, const u8 *dst,
rx_data_eapol_key_3_of_4(wt, dst, src, data, len);
break;
case WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC:
rx_data_eapol_key_4_of_4(wt, dst, src, data, len);
if (key_data_length == 0)
rx_data_eapol_key_4_of_4(wt, dst, src, data,
len);
else
rx_data_eapol_key_2_of_4(wt, dst, src, data,
len);
break;
default:
wpa_printf(MSG_DEBUG, "Unsupported EAPOL-Key frame");

2
wlantest/wlantest.h
View file

@ -70,6 +70,8 @@ struct wlantest_sta {
u8 snonce[32]; /* SNonce from the previous EAPOL-Key msg 2/4 */
struct wpa_ptk ptk; /* Derived PTK */
int ptk_set;
struct wpa_ptk tptk; /* Derived PTK during rekeying */
int tptk_set;
u8 rsc_tods[16 + 1][6];
u8 rsc_fromds[16 + 1][6];
u8 ap_sa_query_tr[2];