From: Jouni Malinen <quic_jouni@quicinc.com>
Date: Sun, 16 Oct 2022 13:38:27 +0000 (+0300)
Subject: FT: Reassociation Response frame validation for FT-SAE-EXT-KEY
X-Git-Tag: hostap_2_11~1637
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eda4ba081c6b2196c56cf40cf1e3e540ce9c8af1;p=thirdparty%2Fhostap.git

FT: Reassociation Response frame validation for FT-SAE-EXT-KEY

Cover the variable length MIC field when validating the Reassociation
Response frame.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>
---

diff --git a/src/rsn_supp/wpa_ft.c b/src/rsn_supp/wpa_ft.c
index e163b3b0e..7254d6bb5 100644
--- a/src/rsn_supp/wpa_ft.c
+++ b/src/rsn_supp/wpa_ft.c
@@ -1008,10 +1008,8 @@ int wpa_ft_validate_reassoc_resp(struct wpa_sm *sm, const u8 *ies,
 	u8 mic[WPA_EAPOL_KEY_MIC_MAX_LEN];
 	const u8 *kck;
 	size_t kck_len;
-	int use_sha384 = wpa_key_mgmt_sha384(sm->key_mgmt);
-	const u8 *anonce, *snonce, *fte_mic;
-	u8 fte_elem_count;
-	int own_rsnxe_used, rsnxe_used;
+	int own_rsnxe_used;
+	size_t mic_len;
 
 	wpa_hexdump(MSG_DEBUG, "FT: Response IEs", ies, ies_len);
 
@@ -1040,49 +1038,37 @@ int wpa_ft_validate_reassoc_resp(struct wpa_sm *sm, const u8 *ies,
 		return -1;
 	}
 
-	if (use_sha384) {
-		struct rsn_ftie_sha384 *ftie;
-
-		ftie = (struct rsn_ftie_sha384 *) parse.ftie;
-		if (!ftie || parse.ftie_len < sizeof(*ftie)) {
-			wpa_printf(MSG_DEBUG, "FT: Invalid FTIE");
-			return -1;
-		}
-
-		anonce = ftie->anonce;
-		snonce = ftie->snonce;
-		rsnxe_used = ftie->mic_control[0] & 0x01;
-		fte_elem_count = ftie->mic_control[1];
-		fte_mic = ftie->mic;
-	} else {
-		struct rsn_ftie *ftie;
-
-		ftie = (struct rsn_ftie *) parse.ftie;
-		if (!ftie || parse.ftie_len < sizeof(*ftie)) {
-			wpa_printf(MSG_DEBUG, "FT: Invalid FTIE");
-			return -1;
-		}
+	if (sm->key_mgmt == WPA_KEY_MGMT_FT_SAE_EXT_KEY &&
+	    sm->pmk_r1_len == SHA512_MAC_LEN)
+		mic_len = 32;
+	else if ((sm->key_mgmt == WPA_KEY_MGMT_FT_SAE_EXT_KEY &&
+		  sm->pmk_r1_len == SHA384_MAC_LEN) ||
+		 wpa_key_mgmt_sha384(sm->key_mgmt))
+		mic_len = 24;
+	else
+		mic_len = 16;
 
-		anonce = ftie->anonce;
-		snonce = ftie->snonce;
-		rsnxe_used = ftie->mic_control[0] & 0x01;
-		fte_elem_count = ftie->mic_control[1];
-		fte_mic = ftie->mic;
+	if (!parse.ftie || !parse.fte_anonce || !parse.fte_snonce ||
+	    parse.fte_mic_len != mic_len) {
+		wpa_printf(MSG_DEBUG,
+			   "FT: Invalid FTE (fte_mic_len=%zu mic_len=%zu)",
+			   parse.fte_mic_len, mic_len);
+		return -1;
 	}
 
-	if (os_memcmp(snonce, sm->snonce, WPA_NONCE_LEN) != 0) {
+	if (os_memcmp(parse.fte_snonce, sm->snonce, WPA_NONCE_LEN) != 0) {
 		wpa_printf(MSG_DEBUG, "FT: SNonce mismatch in FTIE");
 		wpa_hexdump(MSG_DEBUG, "FT: Received SNonce",
-			    snonce, WPA_NONCE_LEN);
+			    parse.fte_snonce, WPA_NONCE_LEN);
 		wpa_hexdump(MSG_DEBUG, "FT: Expected SNonce",
 			    sm->snonce, WPA_NONCE_LEN);
 		return -1;
 	}
 
-	if (os_memcmp(anonce, sm->anonce, WPA_NONCE_LEN) != 0) {
+	if (os_memcmp(parse.fte_anonce, sm->anonce, WPA_NONCE_LEN) != 0) {
 		wpa_printf(MSG_DEBUG, "FT: ANonce mismatch in FTIE");
 		wpa_hexdump(MSG_DEBUG, "FT: Received ANonce",
-			    anonce, WPA_NONCE_LEN);
+			    parse.fte_anonce, WPA_NONCE_LEN);
 		wpa_hexdump(MSG_DEBUG, "FT: Expected ANonce",
 			    sm->anonce, WPA_NONCE_LEN);
 		return -1;
@@ -1129,10 +1115,10 @@ int wpa_ft_validate_reassoc_resp(struct wpa_sm *sm, const u8 *ies,
 		count += ieee802_11_ie_count(parse.ric, parse.ric_len);
 	if (parse.rsnxe)
 		count++;
-	if (fte_elem_count != count) {
+	if (parse.fte_elem_count != count) {
 		wpa_printf(MSG_DEBUG, "FT: Unexpected IE count in MIC "
 			   "Control: received %u expected %u",
-			   fte_elem_count, count);
+			   parse.fte_elem_count, count);
 		return -1;
 	}
 
@@ -1156,14 +1142,15 @@ int wpa_ft_validate_reassoc_resp(struct wpa_sm *sm, const u8 *ies,
 		return -1;
 	}
 
-	if (os_memcmp_const(mic, fte_mic, 16) != 0) {
+	if (os_memcmp_const(mic, parse.fte_mic, mic_len) != 0) {
 		wpa_printf(MSG_DEBUG, "FT: Invalid MIC in FTIE");
-		wpa_hexdump(MSG_MSGDUMP, "FT: Received MIC", fte_mic, 16);
-		wpa_hexdump(MSG_MSGDUMP, "FT: Calculated MIC", mic, 16);
+		wpa_hexdump(MSG_MSGDUMP, "FT: Received MIC",
+			    parse.fte_mic, mic_len);
+		wpa_hexdump(MSG_MSGDUMP, "FT: Calculated MIC", mic, mic_len);
 		return -1;
 	}
 
-	if (rsnxe_used && !sm->ap_rsnxe) {
+	if (parse.fte_rsnxe_used && !sm->ap_rsnxe) {
 		wpa_printf(MSG_INFO,
 			   "FT: FTE indicated that AP uses RSNXE, but RSNXE was not included in Beacon/Probe Response frames");
 		return -1;