[PATCH v2 13/17] MLD STA: Add support for group rekeying

[Veerendranath Jakkam]

Add support for group rekeying in MLO connection. Parse per link MLO
GTK/IGTK/BIGTK KDEs from Group Key msg 1/2 and configure to driver.

Signed-off-by: Veerendranath Jakkam <quic_vjakkam at quicinc.com>
---
 src/rsn_supp/wpa.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 103 insertions(+), 3 deletions(-)

diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
index db97a2b..b454159 100644
--- a/src/rsn_supp/wpa.c
+++ b/src/rsn_supp/wpa.c
@@ -2829,6 +2829,99 @@ static int wpa_supplicant_send_2_of_2(struct wpa_sm *sm,
 }
 
 
+static void wpa_supplicant_process_mlo_1_of_2(struct wpa_sm *sm,
+					      const unsigned char *src_addr,
+					      const struct wpa_eapol_key *key,
+					      const u8 *key_data,
+					      size_t key_data_len, u16 ver)
+{
+	u16 key_info;
+	u8 i;
+	int rekey;
+	struct wpa_eapol_ie_parse ie;
+
+	if (!sm->msg_3_of_4_ok && !wpa_fils_is_completed(sm)) {
+		wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
+			"MLO RSN: Group Key Handshake started prior to completion of 4-way handshake");
+		goto failed;
+	}
+
+	rekey = wpa_sm_get_state(sm) == WPA_COMPLETED;
+	wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG, "MLO RSN: RX message 1 of Group "
+		"Key Handshake from " MACSTR " (ver=%d)", MAC2STR(src_addr),
+		ver);
+
+	key_info = WPA_GET_BE16(key->key_info);
+
+	wpa_sm_set_state(sm, WPA_GROUP_HANDSHAKE);
+
+	wpa_hexdump_key(MSG_DEBUG, "MLO RSN: msg 1/2 key data", key_data,
+			key_data_len);
+	if (wpa_supplicant_parse_ies(key_data, key_data_len, &ie) < 0)
+		goto failed;
+
+	if (!ie.valid_mlo_gtks) {
+		wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
+			"MLO RSN: No MLO GTK KDE in Group Key msg 1/2");
+		goto failed;
+	}
+
+	if (!(key_info & WPA_KEY_INFO_ENCR_KEY_DATA)) {
+		wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
+			"MLO RSN: MLO GTK KDE in unencrypted key data");
+		goto failed;
+	}
+
+	if (mlo_ieee80211w_set_keys(sm, &ie) < 0)
+		wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
+			"MLO RSN: Failed to configure MLO IGTK");
+
+	for (i = 0; i < MAX_NUM_MLO_LINKS; i++) {
+		if (!(sm->mlo.setup_links & BIT(i)))
+			continue;
+
+		if (!ie.mlo_gtk[i]) {
+			/*
+			 * AP may send group keys for subset of the all links
+			 * during rekey
+			 */
+			if (rekey)
+				continue;
+
+			wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
+				"MLO RSN: GTK not found for link ID %u", i);
+			goto failed;
+		}
+
+		if (wpa_supplicant_mlo_gtk(sm, i, ie.mlo_gtk[i],
+					   ie.mlo_gtk_len[i], key_info))
+			goto failed;
+	}
+
+	if (wpa_supplicant_send_2_of_2(sm, key, ver, key_info) < 0)
+		goto failed;
+
+	if (rekey) {
+		wpa_msg(sm->ctx->msg_ctx, MSG_INFO, "MLO RSN: Group rekeying "
+			"completed with " MACSTR " [GTK=%s]",
+			MAC2STR(sm->bssid), wpa_cipher_txt(sm->group_cipher));
+		wpa_sm_cancel_auth_timeout(sm);
+		wpa_sm_set_state(sm, WPA_COMPLETED);
+	} else {
+		wpa_supplicant_key_neg_complete(sm, sm->bssid,
+						key_info &
+						WPA_KEY_INFO_SECURE);
+	}
+
+	wpa_sm_set_rekey_offload(sm);
+
+	return;
+
+failed:
+	wpa_sm_deauthenticate(sm, WLAN_REASON_UNSPECIFIED);
+}
+
+
 static void wpa_supplicant_process_1_of_2(struct wpa_sm *sm,
 					  const unsigned char *src_addr,
 					  const struct wpa_eapol_key *key,
@@ -3466,9 +3559,16 @@ int wpa_sm_rx_eapol(struct wpa_sm *sm, const u8 *src_addr,
 		if ((mic_len && (key_info & WPA_KEY_INFO_MIC)) ||
 		    (!mic_len && (key_info & WPA_KEY_INFO_ENCR_KEY_DATA))) {
 			/* 1/2 Group Key Handshake */
-			wpa_supplicant_process_1_of_2(sm, src_addr, key,
-						      key_data, key_data_len,
-						      ver);
+			if (sm->mlo.setup_links)
+				wpa_supplicant_process_mlo_1_of_2(sm, src_addr,
+								  key, key_data,
+								  key_data_len,
+								  ver);
+			else
+				wpa_supplicant_process_1_of_2(sm, src_addr, key,
+							      key_data,
+							      key_data_len,
+							      ver);
 		} else {
 			wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
 				"WPA: EAPOL-Key (Group) without Mic/Encr bit - "
-- 
2.7.4