DPP2: Presence Announcement processing at Configurator

Process received Presence Announcement frames and initiate
Authentication exchange if matching information is available on the
Configurator.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

src/common/dpp.c

@@ -2246,6 +2246,7 @@ static int dpp_channel_local_list(struct dpp_authentication *auth,
 
 
 static int dpp_prepare_channel_list(struct dpp_authentication *auth,
+				    unsigned int neg_freq,
 				    struct hostapd_hw_modes *own_modes,
 				    u16 num_modes)
 {
@@ -2253,6 +2254,14 @@ static int dpp_prepare_channel_list(struct dpp_authentication *auth,
 	char freqs[DPP_BOOTSTRAP_MAX_FREQ * 6 + 10], *pos, *end;
 	unsigned int i;
 
+	if (!own_modes) {
+		if (!neg_freq)
+			return -1;
+		auth->num_freq = 1;
+		auth->freq[0] = neg_freq;
+		return 0;
+	}
+
 	if (auth->peer_bi->num_freq > 0)
 		res = dpp_channel_intersect(auth, own_modes, num_modes);
 	else
@@ -2392,7 +2401,7 @@ struct dpp_authentication * dpp_auth_init(struct dpp_global *dpp, void *msg_ctx,
 	auth->curve = peer_bi->curve;
 
 	if (dpp_autogen_bootstrap_key(auth) < 0 ||
-	    dpp_prepare_channel_list(auth, own_modes, num_modes) < 0)
+	    dpp_prepare_channel_list(auth, neg_freq, own_modes, num_modes) < 0)
 		goto fail;
 
 #ifdef CONFIG_TESTING_OPTIONS
@@ -2488,6 +2497,8 @@ struct dpp_authentication * dpp_auth_init(struct dpp_global *dpp, void *msg_ctx,
 	}
 #endif /* CONFIG_TESTING_OPTIONS */
 
+	if (neg_freq && auth->num_freq == 1 && auth->freq[0] == neg_freq)
+		neg_freq = 0;
 	auth->req_msg = dpp_auth_build_req(auth, pi, nonce_len, r_pubkey_hash,
 					   i_pubkey_hash, neg_freq);
 	if (!auth->req_msg)
@@ -10597,10 +10608,29 @@ void dpp_bootstrap_find_pair(struct dpp_global *dpp, const u8 *i_bootstrap,
 		if (*own_bi && *peer_bi)
 			break;
 	}
-
 }
 
 
+#ifdef CONFIG_DPP2
+struct dpp_bootstrap_info * dpp_bootstrap_find_chirp(struct dpp_global *dpp,
+						     const u8 *hash)
+{
+	struct dpp_bootstrap_info *bi;
+
+	if (!dpp)
+		return NULL;
+
+	dl_list_for_each(bi, &dpp->bootstrap, struct dpp_bootstrap_info, list) {
+		if (!bi->own && os_memcmp(bi->pubkey_hash_chirp, hash,
+					  SHA256_MAC_LEN) == 0)
+			return bi;
+	}
+
+	return NULL;
+}
+#endif /* CONFIG_DPP2 */
+
+
 static int dpp_nfc_update_bi_channel(struct dpp_bootstrap_info *own_bi,
 				     struct dpp_bootstrap_info *peer_bi)
 {

src/common/dpp.h

@@ -578,6 +578,8 @@ void dpp_bootstrap_find_pair(struct dpp_global *dpp, const u8 *i_bootstrap,
 			     const u8 *r_bootstrap,
 			     struct dpp_bootstrap_info **own_bi,
 			     struct dpp_bootstrap_info **peer_bi);
+struct dpp_bootstrap_info * dpp_bootstrap_find_chirp(struct dpp_global *dpp,
+						     const u8 *hash);
 int dpp_configurator_add(struct dpp_global *dpp, const char *cmd);
 int dpp_configurator_remove(struct dpp_global *dpp, const char *id);
 int dpp_configurator_get_key_id(struct dpp_global *dpp, unsigned int id,

wpa_supplicant/dpp_supplicant.c

@@ -1694,6 +1694,67 @@ static void wpas_dpp_remove_bi(void *ctx, struct dpp_bootstrap_info *bi)
 		wpas_dpp_chirp_stop(wpa_s);
 }
 
+
+static void
+wpas_dpp_rx_presence_announcement(struct wpa_supplicant *wpa_s, const u8 *src,
+				  const u8 *hdr, const u8 *buf, size_t len,
+				  unsigned int freq)
+{
+	const u8 *r_bootstrap;
+	u16 r_bootstrap_len;
+	struct dpp_bootstrap_info *peer_bi;
+	struct dpp_authentication *auth;
+
+	if (!wpa_s->dpp)
+		return;
+
+	if (wpa_s->dpp_auth) {
+		wpa_printf(MSG_DEBUG,
+			   "DPP: Ignore Presence Announcement during ongoing Authentication");
+		return;
+	}
+
+	wpa_printf(MSG_DEBUG, "DPP: Presence Announcement from " MACSTR,
+		   MAC2STR(src));
+
+	r_bootstrap = dpp_get_attr(buf, len, DPP_ATTR_R_BOOTSTRAP_KEY_HASH,
+				   &r_bootstrap_len);
+	if (!r_bootstrap || r_bootstrap_len != SHA256_MAC_LEN) {
+		wpa_msg(wpa_s, MSG_INFO, DPP_EVENT_FAIL
+			"Missing or invalid required Responder Bootstrapping Key Hash attribute");
+		return;
+	}
+	wpa_hexdump(MSG_MSGDUMP, "DPP: Responder Bootstrapping Key Hash",
+		    r_bootstrap, r_bootstrap_len);
+	peer_bi = dpp_bootstrap_find_chirp(wpa_s->dpp, r_bootstrap);
+	if (!peer_bi) {
+		wpa_printf(MSG_DEBUG,
+			   "DPP: No matching bootstrapping information found");
+		return;
+	}
+
+	auth = dpp_auth_init(wpa_s->dpp, wpa_s, peer_bi, NULL,
+			     DPP_CAPAB_CONFIGURATOR, freq, NULL, 0);
+	if (!auth)
+		return;
+	wpas_dpp_set_testing_options(wpa_s, auth);
+	if (dpp_set_configurator(auth, wpa_s->dpp_configurator_params) < 0) {
+		dpp_auth_deinit(auth);
+		return;
+	}
+
+	auth->neg_freq = freq;
+
+	if (!is_zero_ether_addr(peer_bi->mac_addr))
+		os_memcpy(auth->peer_mac_addr, peer_bi->mac_addr, ETH_ALEN);
+
+	wpa_s->dpp_auth = auth;
+	if (wpas_dpp_auth_init_next(wpa_s) < 0) {
+		dpp_auth_deinit(wpa_s->dpp_auth);
+		wpa_s->dpp_auth = NULL;
+	}
+}
+
 #endif /* CONFIG_DPP2 */
 
 
@@ -2239,6 +2300,10 @@ void wpas_dpp_rx_action(struct wpa_supplicant *wpa_s, const u8 *src,
 	case DPP_PA_CONNECTION_STATUS_RESULT:
 		wpas_dpp_rx_conn_status_result(wpa_s, src, hdr, buf, len);
 		break;
+	case DPP_PA_PRESENCE_ANNOUNCEMENT:
+		wpas_dpp_rx_presence_announcement(wpa_s, src, hdr, buf, len,
+						  freq);
+		break;
 #endif /* CONFIG_DPP2 */
 	default:
 		wpa_printf(MSG_DEBUG,