[PATCH v4 08/13] MLD STA: Add support for validating MLO KDEs for 4WHS EAPOL frames
Veerendranath Jakkam
quic_vjakkam at quicinc.com
Thu Nov 3 01:08:51 PDT 2022
Validate new KDEs defined for MLO connection in EAPOL 1/4 and 3/4 and
reject the Four-Way handshake frames if any of the new KDE data is not
matching expected key data.
Signed-off-by: Veerendranath Jakkam <quic_vjakkam at quicinc.com>
---
src/rsn_supp/wpa.c | 171 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 170 insertions(+), 1 deletion(-)
diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
index 0e6e4d1c1..95f9e930a 100644
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -773,6 +773,13 @@ static u8 *wpa_mlo_link_kde(struct wpa_sm *sm, u8 *pos)
return pos;
}
+
+static bool is_valid_ap_mld_mac_kde(struct wpa_sm *sm, const u8 *mac_kde)
+{
+ return mac_kde && !os_memcmp(mac_kde, sm->mlo.ap_mld_addr, ETH_ALEN);
+}
+
+
static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
const unsigned char *src_addr,
const struct wpa_eapol_key *key,
@@ -828,6 +835,12 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
}
}
+ if (sm->mlo.valid_links && !is_valid_ap_mld_mac_kde(sm, ie.mac_addr)) {
+ wpa_printf(MSG_INFO,
+ "RSN: Discard EAPOL-Key msg 1/4 with invalid AP MLD MAC address KDE");
+ return;
+ }
+
res = wpa_supplicant_get_pmk(sm, src_addr, ie.pmkid);
if (res == -2) {
wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG, "RSN: Do not reply to "
@@ -2131,6 +2144,133 @@ int wpa_supplicant_send_4_of_4(struct wpa_sm *sm, const unsigned char *dst,
}
+static int wpa_supplicant_validate_link_kde(struct wpa_sm *sm,
+ u8 link_id,
+ const u8 *link_kde,
+ size_t link_kde_len)
+{
+ size_t rsne_len = 0, rsnxe_len = 0;
+ const u8 *rsne = NULL, *rsnxe = NULL;
+
+ if (!link_kde) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: MLO Link KDE is not found for link ID %d",
+ link_id);
+ return -1;
+ }
+
+ if (os_memcmp(sm->mlo.links[link_id].bssid,
+ &link_kde[RSN_MLO_LINK_KDE_LINK_MAC_INDEX], ETH_ALEN)) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: MLO Link %u MAC address not matching with assoc response",
+ link_id);
+ return -1;
+ }
+
+ if (link_kde[0] & RSN_MLO_LINK_KDE_LI_RSNE_INFO) {
+ rsne = link_kde + RSN_MLO_LINK_KDE_FIXED_LENGTH;
+ if (link_kde_len < (RSN_MLO_LINK_KDE_FIXED_LENGTH + 2) ||
+ link_kde_len <
+ (RSN_MLO_LINK_KDE_FIXED_LENGTH + 2 + rsne[1]))
+ return -1;
+
+ rsne_len = rsne[1] + 2;
+ }
+
+ if (!rsne) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: RSNE not present in MLO Link %u KDE",
+ link_id);
+ return -1;
+ }
+
+ if (link_kde[0] & RSN_MLO_LINK_KDE_LI_RSNXE_INFO) {
+ rsnxe = link_kde + RSN_MLO_LINK_KDE_FIXED_LENGTH + rsne_len;
+ if (link_kde_len <
+ (RSN_MLO_LINK_KDE_FIXED_LENGTH + rsne_len + 2) ||
+ link_kde_len <
+ (RSN_MLO_LINK_KDE_FIXED_LENGTH + rsne_len + 2 + rsnxe[1]))
+ return -1;
+
+ rsnxe_len = rsnxe[1] + 2;
+ }
+
+ if (wpa_compare_rsn_ie(wpa_key_mgmt_ft(sm->key_mgmt),
+ sm->mlo.links[link_id].ap_rsne,
+ sm->mlo.links[link_id].ap_rsne_len,
+ rsne, rsne_len)) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN MLO: IE in 3/4 msg does not match with IE in Beacon/ProbeResp for link ID %u",
+ link_id);
+ wpa_hexdump(MSG_INFO, "RSNE in Beacon/ProbeResp",
+ sm->mlo.links[link_id].ap_rsne,
+ sm->mlo.links[link_id].ap_rsne_len);
+ wpa_hexdump(MSG_INFO, "RSNE in EAPOL-Key msg 3/4",
+ rsne, rsne_len);
+ return -1;
+ }
+
+ if ((sm->mlo.links[link_id].ap_rsnxe && !rsnxe) ||
+ (!sm->mlo.links[link_id].ap_rsnxe && rsnxe) ||
+ (sm->mlo.links[link_id].ap_rsnxe && rsnxe &&
+ (sm->mlo.links[link_id].ap_rsnxe_len != rsnxe_len ||
+ os_memcmp(sm->mlo.links[link_id].ap_rsnxe, rsnxe,
+ sm->mlo.links[link_id].ap_rsnxe_len) != 0))) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
+ "RSN MLO: RSNXE mismatch between Beacon/ProbeResp and EAPOL-Key msg 3/4 for link ID %u",
+ link_id);
+ wpa_hexdump(MSG_INFO, "RSNXE in Beacon/ProbeResp",
+ sm->mlo.links[link_id].ap_rsnxe,
+ sm->mlo.links[link_id].ap_rsnxe_len);
+ wpa_hexdump(MSG_INFO, "RSNXE in EAPOL-Key msg 3/4",
+ rsnxe, rsnxe_len);
+ wpa_sm_deauthenticate(sm, WLAN_REASON_IE_IN_4WAY_DIFFERS);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static int wpa_validate_mlo_ieee80211w_kdes(struct wpa_sm *sm,
+ u8 link_id,
+ struct wpa_eapol_ie_parse *ie)
+{
+ if (!ie->mlo_igtk[link_id]) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: IGTK not found for link ID %u", link_id);
+ return -1;
+ }
+
+ if (ie->mlo_igtk_len[link_id] != RSN_MLO_IGTK_KDE_PREFIX_LENGTH +
+ (unsigned int) wpa_cipher_key_len(sm->mgmt_group_cipher)) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
+ "WPA MLO: Invalid IGTK KDE length %lu for link ID %u",
+ (unsigned long) ie->mlo_igtk_len, link_id);
+ return -1;
+ }
+
+ if (!sm->beacon_prot)
+ return 0;
+
+ if (!ie->mlo_bigtk[link_id]) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: BIGTK not found for link ID %u", link_id);
+ return -1;
+ }
+
+ if (ie->mlo_bigtk_len[link_id] != RSN_MLO_BIGTK_KDE_PREFIX_LENGTH +
+ (unsigned int) wpa_cipher_key_len(sm->mgmt_group_cipher)) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
+ "WPA MLO: Invalid BIGTK KDE length %lu for link ID %u",
+ (unsigned long) ie->mlo_bigtk_len, link_id);
+ return -1;
+ }
+
+ return 0;
+}
+
+
static void wpa_supplicant_process_mlo_3_of_4(struct wpa_sm *sm,
const struct wpa_eapol_key *key,
u16 ver, const u8 *key_data,
@@ -2138,7 +2278,7 @@ static void wpa_supplicant_process_mlo_3_of_4(struct wpa_sm *sm,
{
u16 key_info, keylen;
struct wpa_eapol_ie_parse ie;
- int res;
+ int res, i;
wpa_sm_set_state(sm, WPA_4WAY_HANDSHAKE);
wpa_dbg(sm->ctx->msg_ctx, MSG_INFO, "RSN MLO: RX message 3 of 4-Way "
@@ -2165,6 +2305,35 @@ static void wpa_supplicant_process_mlo_3_of_4(struct wpa_sm *sm,
goto failed;
}
+ if (!is_valid_ap_mld_mac_kde(sm, ie.mac_addr)) {
+ wpa_printf(MSG_DEBUG, "RSN: Invalid AP MLD MAC address KDE");
+ goto failed;
+ }
+
+ for (i = 0; i < MAX_NUM_MLD_LINKS; i++) {
+ if (!(sm->mlo.req_links & BIT(i)))
+ continue;
+
+ if (wpa_supplicant_validate_link_kde(sm, i, ie.mlo_link[i],
+ ie.mlo_link_len[i]) < 0)
+ goto failed;
+
+ if (!(sm->mlo.valid_links & BIT(i)))
+ continue;
+
+ if (!ie.mlo_gtk[i]) {
+ wpa_msg(sm->ctx->msg_ctx, MSG_ERROR,
+ "RSN: GTK not found for link ID %u", i);
+ goto failed;
+ }
+
+ if (!wpa_sm_pmf_enabled(sm))
+ continue;
+
+ if (wpa_validate_mlo_ieee80211w_kdes(sm, i, &ie) < 0)
+ goto failed;
+ }
+
#ifdef CONFIG_IEEE80211R
if (wpa_key_mgmt_ft(sm->key_mgmt) &&
wpa_supplicant_validate_ie_ft(sm, sm->bssid, &ie) < 0)
--
2.25.1
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