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Use Secure=1 in PTK rekeying EAPOL-Key msg 1/4 and 2/4

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IEEE Std 802.11-2020 is ambiguous on how the Secure bit is set in
EAPOL-Key msg 1/4 and 2/4 in the case where 4-way handshake is use to
rekey the PTK. 12.7.2 describes this with "set to 1 once the initial key
exchange is complete" while 12.7.6 shows EAPOL-Key msg 1/4 and 2/4 using
Secure=0 without any consideration on whether the handshake is for
rekeying.

TGme seems to be moving towards clarifying this to use Secure=1 based on
there being a shared PTKSA between the Authenticator and the Supplicant.
In other words, this would use Secure=1 in EAPOL-Key msg 1/4 and 2/4 in
the case of rekeying. Change implementation to match that. This bit was
already practically ignored on the reception side, so this should not
have impact on actual functionality beyond this one bit changing its
value in the frame.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
This commit is contained in:
Jouni Malinen 2022-05-16 17:34:12 +03:00 committed by Jouni Malinen
parent d2ce1b4d6c
commit bc36991791
2 changed files with 7 additions and 2 deletions
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7
src/ap/wpa_auth.c
View file

@ -2192,6 +2192,7 @@ SM_STATE(WPA_PTK, PTKSTART)
{
u8 buf[2 + RSN_SELECTOR_LEN + PMKID_LEN], *pmkid = NULL;
size_t pmkid_len = 0;
u16 key_info;
SM_ENTRY_MA(WPA_PTK, PTKSTART, wpa_ptk);
sm->PTKRequest = false;
@ -2295,8 +2296,10 @@ SM_STATE(WPA_PTK, PTKSTART)
}
if (!pmkid)
pmkid_len = 0;
wpa_send_eapol(sm->wpa_auth, sm,
WPA_KEY_INFO_ACK | WPA_KEY_INFO_KEY_TYPE, NULL,
key_info = WPA_KEY_INFO_ACK | WPA_KEY_INFO_KEY_TYPE;
if (sm->pairwise_set && sm->wpa != WPA_VERSION_WPA)
key_info |= WPA_KEY_INFO_SECURE;
wpa_send_eapol(sm->wpa_auth, sm, key_info, NULL,
sm->ANonce, pmkid, pmkid_len, 0, 0);
}

2
src/rsn_supp/wpa.c
View file

@ -552,6 +552,8 @@ int wpa_supplicant_send_2_of_4(struct wpa_sm *sm, const unsigned char *dst,
sm->proto == WPA_PROTO_OSEN) ?
EAPOL_KEY_TYPE_RSN : EAPOL_KEY_TYPE_WPA;
key_info = ver | WPA_KEY_INFO_KEY_TYPE;
if (sm->ptk_set && sm->proto != WPA_PROTO_WPA)
key_info |= WPA_KEY_INFO_SECURE;
if (mic_len)
key_info |= WPA_KEY_INFO_MIC;
else