mesh: Generate a separate TX IGTK if PMF is enabled

Previous implementation was incorrectly using MGTK also as the IGTK and
doing this regardless of whether PMF was enabled. IGTK needs to be a
independent key and this commit does that at the local TX side.

The current AMPE element construction and parsing is quite broken, so
this does not get add the IGTKdata field there.

Signed-off-by: Jouni Malinen <j@w1.fi>

wpa_supplicant/mesh_rsn.c

@@ -177,9 +177,19 @@ static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
 	if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0)
 		return -1;
 
-	/* group mgmt */
-	wpa_drv_set_key(rsn->wpa_s, WPA_ALG_IGTK, NULL, 4, 1,
-			seq, sizeof(seq), rsn->mgtk, sizeof(rsn->mgtk));
+#ifdef CONFIG_IEEE80211W
+	if (ieee80211w != NO_MGMT_FRAME_PROTECTION) {
+		if (random_get_bytes(rsn->igtk, 16) < 0)
+			return -1;
+		rsn->igtk_len = 16;
+
+		/* group mgmt */
+		wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX IGTK",
+				rsn->igtk, rsn->igtk_len);
+		wpa_drv_set_key(rsn->wpa_s, WPA_ALG_IGTK, NULL, 4, 1,
+				seq, sizeof(seq), rsn->igtk, rsn->igtk_len);
+	}
+#endif /* CONFIG_IEEE80211W */
 
 	/* group privacy / data frames */
 	wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK",
@@ -195,6 +205,8 @@ static void mesh_rsn_deinit(struct mesh_rsn *rsn)
 {
 	os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk));
 	rsn->mgtk_len = 0;
+	os_memset(rsn->igtk, 0, sizeof(rsn->igtk));
+	rsn->igtk_len = 0;
 	if (rsn->auth)
 		wpa_deinit(rsn->auth);
 }

wpa_supplicant/mesh_rsn.h

@@ -14,6 +14,8 @@ struct mesh_rsn {
 	struct wpa_authenticator *auth;
 	u8 mgtk[WPA_TK_MAX_LEN];
 	size_t mgtk_len;
+	u8 igtk[WPA_TK_MAX_LEN];
+	size_t igtk_len;
 #ifdef CONFIG_SAE
 	struct wpabuf *sae_token;
 	int sae_group_index;