mesh: Avoid use of hardcoded cipher

This moves pairwise, group, and management group ciphers to various mesh
data structures to avoid having to hardcode cipher in number of places
through the code. While CCMP and BIP are still the hardcoded ciphers,
these are now set only in one location.

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

src/ap/ap_config.h

@@ -42,6 +42,9 @@ struct mesh_conf {
 #define MESH_CONF_SEC_AMPE BIT(2)
 	unsigned int security;
 	enum mfp_options ieee80211w;
+	unsigned int pairwise_cipher;
+	unsigned int group_cipher;
+	unsigned int mgmt_group_cipher;
 	int dot11MeshMaxRetries;
 	int dot11MeshRetryTimeout; /* msec */
 	int dot11MeshConfirmTimeout; /* msec */

src/ap/sta_info.h

@@ -88,6 +88,7 @@ struct sta_info {
 	u8 mtk[WPA_TK_MAX_LEN];
 	size_t mtk_len;
 	u8 mgtk_rsc[6];
+	u8 mgtk_key_id;
 	u8 mgtk[WPA_TK_MAX_LEN];
 	size_t mgtk_len;
 	u8 igtk_rsc[6];

wpa_supplicant/mesh.c

@@ -90,6 +90,10 @@ static struct mesh_conf * mesh_config_create(struct wpa_supplicant *wpa_s,
 		else
 			conf->ieee80211w = NO_MGMT_FRAME_PROTECTION;
 	}
+	conf->pairwise_cipher = WPA_CIPHER_CCMP;
+	conf->group_cipher = WPA_CIPHER_CCMP;
+	if (conf->ieee80211w != NO_MGMT_FRAME_PROTECTION)
+		conf->mgmt_group_cipher = WPA_CIPHER_AES_128_CMAC;
 
 	/* defaults */
 	conf->mesh_pp_id = MESH_PATH_PROTOCOL_HWMP;
@@ -343,15 +347,9 @@ int wpa_supplicant_join_mesh(struct wpa_supplicant *wpa_s,
 
 	wpa_supplicant_mesh_deinit(wpa_s);
 
-	if (ssid->key_mgmt & WPA_KEY_MGMT_SAE) {
-		wpa_s->pairwise_cipher = WPA_CIPHER_CCMP;
-		wpa_s->group_cipher = WPA_CIPHER_CCMP;
-		wpa_s->mgmt_group_cipher = 0;
-	} else {
-		wpa_s->pairwise_cipher = WPA_CIPHER_NONE;
-		wpa_s->group_cipher = WPA_CIPHER_NONE;
-		wpa_s->mgmt_group_cipher = 0;
-	}
+	wpa_s->pairwise_cipher = WPA_CIPHER_NONE;
+	wpa_s->group_cipher = WPA_CIPHER_NONE;
+	wpa_s->mgmt_group_cipher = 0;
 
 	os_memset(&params, 0, sizeof(params));
 	params.meshid = ssid->ssid;
@@ -409,6 +407,12 @@ int wpa_supplicant_join_mesh(struct wpa_supplicant *wpa_s,
 		goto out;
 	}
 
+	if (ssid->key_mgmt & WPA_KEY_MGMT_SAE) {
+		wpa_s->pairwise_cipher = wpa_s->mesh_rsn->pairwise_cipher;
+		wpa_s->group_cipher = wpa_s->mesh_rsn->group_cipher;
+		wpa_s->mgmt_group_cipher = wpa_s->mesh_rsn->mgmt_group_cipher;
+	}
+
 	if (wpa_s->ifmsh) {
 		params.ies = wpa_s->ifmsh->mconf->rsn_ie;
 		params.ie_len = wpa_s->ifmsh->mconf->rsn_ie_len;

wpa_supplicant/mesh_mpm.c

@@ -794,30 +794,30 @@ static void mesh_mpm_plink_estab(struct wpa_supplicant *wpa_s,
 
 	if (conf->security & MESH_CONF_SEC_AMPE) {
 		wpa_hexdump_key(MSG_DEBUG, "mesh: MTK", sta->mtk, sta->mtk_len);
-		/* TODO: support for other ciphers */
-		wpa_drv_set_key(wpa_s, WPA_ALG_CCMP, sta->addr, 0, 0,
-				seq, sizeof(seq), sta->mtk, sta->mtk_len);
+		wpa_drv_set_key(wpa_s, wpa_cipher_to_alg(conf->pairwise_cipher),
+				sta->addr, 0, 0, seq, sizeof(seq),
+				sta->mtk, sta->mtk_len);
 
 		wpa_hexdump_key(MSG_DEBUG, "mesh: RX MGTK Key RSC",
 				sta->mgtk_rsc, sizeof(sta->mgtk_rsc));
 		wpa_hexdump_key(MSG_DEBUG, "mesh: RX MGTK",
 				sta->mgtk, sta->mgtk_len);
-		/* TODO: support for other ciphers */
-		/* FIX: key index.. */
-		wpa_drv_set_key(wpa_s, WPA_ALG_CCMP, sta->addr, 1, 0,
+		wpa_drv_set_key(wpa_s, wpa_cipher_to_alg(conf->group_cipher),
+				sta->addr, sta->mgtk_key_id, 0,
 				sta->mgtk_rsc, sizeof(sta->mgtk_rsc),
 				sta->mgtk, sta->mgtk_len);
 
 		if (sta->igtk_len) {
 			wpa_hexdump_key(MSG_DEBUG, "mesh: RX IGTK Key RSC",
 					sta->igtk_rsc, sizeof(sta->igtk_rsc));
-			wpa_hexdump_key(MSG_DEBUG, "RX IGTK",
-					sta->igtk, sta->igtk_len);
-			/* FIX: key index.. */
-			wpa_drv_set_key(wpa_s, WPA_ALG_IGTK, sta->addr,
-					sta->igtk_key_id, 0,
-					sta->igtk_rsc, sizeof(sta->igtk_rsc),
+			wpa_hexdump_key(MSG_DEBUG, "mesh: RX IGTK",
 					sta->igtk, sta->igtk_len);
+			wpa_drv_set_key(
+				wpa_s,
+				wpa_cipher_to_alg(conf->mgmt_group_cipher),
+				sta->addr, sta->igtk_key_id, 0,
+				sta->igtk_rsc, sizeof(sta->igtk_rsc),
+				sta->igtk, sta->igtk_len);
 		}
 	}
 

wpa_supplicant/mesh_rsn.c

@@ -146,17 +146,17 @@ static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
 	wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
 
 	os_memset(&conf, 0, sizeof(conf));
-	conf.wpa = 2;
+	conf.wpa = WPA_PROTO_RSN;
 	conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE;
-	conf.wpa_pairwise = WPA_CIPHER_CCMP;
-	conf.rsn_pairwise = WPA_CIPHER_CCMP;
-	conf.wpa_group = WPA_CIPHER_CCMP;
+	conf.wpa_pairwise = rsn->pairwise_cipher;
+	conf.rsn_pairwise = rsn->pairwise_cipher;
+	conf.wpa_group = rsn->group_cipher;
 	conf.eapol_version = 0;
 	conf.wpa_group_rekey = -1;
 #ifdef CONFIG_IEEE80211W
 	conf.ieee80211w = ieee80211w;
 	if (ieee80211w != NO_MGMT_FRAME_PROTECTION)
-		conf.group_mgmt_cipher = WPA_CIPHER_AES_128_CMAC;
+		conf.group_mgmt_cipher = rsn->mgmt_group_cipher;
 #endif /* CONFIG_IEEE80211W */
 
 	os_memset(&cb, 0, sizeof(cb));
@@ -173,14 +173,14 @@ static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
 	}
 
 	/* TODO: support rekeying */
-	rsn->mgtk_len = wpa_cipher_key_len(WPA_CIPHER_CCMP);
+	rsn->mgtk_len = wpa_cipher_key_len(conf.wpa_group);
 	if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0)
 		return -1;
 	rsn->mgtk_key_id = 1;
 
 #ifdef CONFIG_IEEE80211W
 	if (ieee80211w != NO_MGMT_FRAME_PROTECTION) {
-		rsn->igtk_len = wpa_cipher_key_len(WPA_CIPHER_AES_128_CMAC);
+		rsn->igtk_len = wpa_cipher_key_len(conf.group_mgmt_cipher);
 		if (random_get_bytes(rsn->igtk, rsn->igtk_len) < 0)
 			return -1;
 		rsn->igtk_key_id = 4;
@@ -188,7 +188,8 @@ static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
 		/* 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,
+		wpa_drv_set_key(rsn->wpa_s,
+				wpa_cipher_to_alg(rsn->mgmt_group_cipher), NULL,
 				rsn->igtk_key_id, 1,
 				seq, sizeof(seq), rsn->igtk, rsn->igtk_len);
 	}
@@ -197,8 +198,9 @@ static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
 	/* group privacy / data frames */
 	wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK",
 			rsn->mgtk, rsn->mgtk_len);
-	wpa_drv_set_key(rsn->wpa_s, WPA_ALG_CCMP, NULL, rsn->mgtk_key_id, 1,
-			seq, sizeof(seq), rsn->mgtk, rsn->mgtk_len);
+	wpa_drv_set_key(rsn->wpa_s, wpa_cipher_to_alg(rsn->group_cipher), NULL,
+			rsn->mgtk_key_id, 1, seq, sizeof(seq),
+			rsn->mgtk, rsn->mgtk_len);
 
 	return 0;
 }
@@ -227,6 +229,9 @@ struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s,
 	if (mesh_rsn == NULL)
 		return NULL;
 	mesh_rsn->wpa_s = wpa_s;
+	mesh_rsn->pairwise_cipher = conf->pairwise_cipher;
+	mesh_rsn->group_cipher = conf->group_cipher;
+	mesh_rsn->mgmt_group_cipher = conf->mgmt_group_cipher;
 
 	if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr,
 				 conf->ieee80211w) < 0) {
@@ -464,7 +469,7 @@ int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta)
 	ptr += ETH_ALEN;
 	os_memcpy(ptr, max, ETH_ALEN);
 
-	sta->mtk_len = wpa_cipher_key_len(WPA_CIPHER_CCMP);
+	sta->mtk_len = wpa_cipher_key_len(wpa_s->mesh_rsn->pairwise_cipher);
 	sha256_prf(sta->sae->pmk, SAE_PMK_LEN,
 		   "Temporal Key Derivation", context, sizeof(context),
 		   sta->mtk, sta->mtk_len);
@@ -682,7 +687,8 @@ int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta,
 	 * GTKdata[variable]:
 	 * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4]
 	 */
-	key_len = wpa_cipher_key_len(WPA_CIPHER_CCMP);
+	sta->mgtk_key_id = 1; /* FIX: Where to get Key ID? */
+	key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->group_cipher);
 	if ((int) key_len + WPA_KEY_RSC_LEN + 4 > end - pos) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "mesh: Truncated AMPE element");
 		ret = -1;
@@ -707,7 +713,7 @@ int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta,
 	 * IGTKdata[variable]:
 	 * Key ID[2], IPN[6], IGTK[variable]
 	 */
-	key_len = wpa_cipher_key_len(WPA_CIPHER_AES_128_CMAC);
+	key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->mgmt_group_cipher);
 	if (end - pos >= (int) (2 + 6 + key_len)) {
 		sta->igtk_key_id = WPA_GET_LE16(pos);
 		wpa_printf(MSG_DEBUG, "mesh: IGTKdata - Key ID %u",

wpa_supplicant/mesh_rsn.h

@@ -12,9 +12,12 @@
 struct mesh_rsn {
 	struct wpa_supplicant *wpa_s;
 	struct wpa_authenticator *auth;
+	unsigned int pairwise_cipher;
+	unsigned int group_cipher;
 	u8 mgtk[WPA_TK_MAX_LEN];
 	size_t mgtk_len;
 	u8 mgtk_key_id;
+	unsigned int mgmt_group_cipher;
 	u8 igtk_key_id;
 	u8 igtk[WPA_TK_MAX_LEN];
 	size_t igtk_len;