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wlantest: Update PTK after rekeying even if EAPOL-Key msg 4/4 is missing

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Update TPTK to PTK if a valid EAPOL-Key msg 2/4 and 3/4 are available,
but 4/4 is missing. This avoids certain cases where the new TK could be
derived, but it was not being used to try to decrypt following encrypted
frames.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
This commit is contained in:
Jouni Malinen 2020-04-01 18:46:14 +03:00 committed by Jouni Malinen
parent 0dc58cfa95
commit 08ac6f807d
1 changed files with 39 additions and 12 deletions
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49
wlantest/rx_data.c
View file

@ -330,6 +330,26 @@ skip_replay_det:
}
static u8 * try_ptk_decrypt(struct wlantest *wt, struct wlantest_sta *sta,
const struct ieee80211_hdr *hdr, int keyid,
const u8 *data, size_t len,
const u8 *tk, size_t tk_len, size_t *dlen)
{
u8 *decrypted = NULL;
if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
decrypted = ccmp_256_decrypt(tk, hdr, data, len, dlen);
else if (sta->pairwise_cipher == WPA_CIPHER_GCMP ||
sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
decrypted = gcmp_decrypt(tk, tk_len, hdr, data, len, dlen);
else
decrypted = ccmp_decrypt(tk, hdr, data, len, dlen);
write_decrypted_note(wt, decrypted, tk, tk_len, keyid);
return decrypted;
}
static void rx_data_bss_prot(struct wlantest *wt,
const struct ieee80211_hdr *hdr, size_t hdrlen,
const u8 *qos, const u8 *dst, const u8 *src,
@ -562,18 +582,9 @@ skip_replay_det:
} else if (sta->pairwise_cipher == WPA_CIPHER_WEP40) {
decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
} else if (sta->ptk_set) {
if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
decrypted = ccmp_256_decrypt(sta->ptk.tk, hdr, data,
len, &dlen);
else if (sta->pairwise_cipher == WPA_CIPHER_GCMP ||
sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
decrypted = gcmp_decrypt(sta->ptk.tk, sta->ptk.tk_len,
hdr, data, len, &dlen);
else
decrypted = ccmp_decrypt(sta->ptk.tk, hdr, data, len,
decrypted = try_ptk_decrypt(wt, sta, hdr, keyid, data, len,
sta->ptk.tk, sta->ptk.tk_len,
&dlen);
write_decrypted_note(wt, decrypted, sta->ptk.tk,
sta->ptk.tk_len, keyid);
} else {
decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, keyid,
data, len, &dlen);
@ -620,6 +631,22 @@ check_zero_tk:
dlen, 1, peer_addr);
write_pcap_decrypted(wt, (const u8 *) hdr, hdrlen,
decrypted, dlen);
} else if (sta->tptk_set) {
/* Check whether TPTK has a matching TK that could be used to
* decrypt the frame. That could happen if EAPOL-Key msg 4/4
* was missing in the capture and this was PTK rekeying. */
decrypted = try_ptk_decrypt(wt, sta, hdr, keyid, data, len,
sta->tptk.tk, sta->tptk.tk_len,
&dlen);
if (decrypted) {
add_note(wt, MSG_DEBUG,
"Update PTK (rekeying; no valid EAPOL-Key msg 4/4 seen)");
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));
}
} else {
if (!try_ptk_iter && !only_zero_tk)
add_note(wt, MSG_DEBUG, "Failed to decrypt frame");