DPP2: Reconfig Authentication Confirm processing

Extend Enrollee functionality to process Reconfig Authentication
Confirm message and start GAS client.

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

src/common/dpp.c

@@ -4756,8 +4756,15 @@ static void dpp_copy_netaccesskey(struct dpp_authentication *auth,
 	unsigned char *der = NULL;
 	int der_len;
 	EC_KEY *eckey;
+	EVP_PKEY *own_key;
 
-	eckey = EVP_PKEY_get1_EC_KEY(auth->own_protocol_key);
+	own_key = auth->own_protocol_key;
+#ifdef CONFIG_DPP2
+	if (auth->reconfig_connector_key == DPP_CONFIG_REUSEKEY &&
+	    auth->reconfig_old_protocol_key)
+		own_key = auth->reconfig_old_protocol_key;
+#endif /* CONFIG_DPP2 */
+	eckey = EVP_PKEY_get1_EC_KEY(own_key);
 	if (!eckey)
 		return;
 

src/common/dpp.h

@@ -243,6 +243,7 @@ struct dpp_authentication {
 	u8 waiting_pubkey_hash[SHA256_MAC_LEN];
 	int response_pending;
 	int reconfig;
+	enum dpp_connector_key reconfig_connector_key;
 	enum dpp_status_error auth_resp_status;
 	enum dpp_status_error conf_resp_status;
 	u8 peer_mac_addr[ETH_ALEN];
@@ -661,6 +662,8 @@ dpp_reconfig_auth_req_rx(struct dpp_global *dpp, void *msg_ctx,
 struct wpabuf *
 dpp_reconfig_auth_resp_rx(struct dpp_authentication *auth, const u8 *hdr,
 			  const u8 *attr_start, size_t attr_len);
+int dpp_reconfig_auth_conf_rx(struct dpp_authentication *auth, const u8 *hdr,
+			      const u8 *attr_start, size_t attr_len);
 
 #endif /* CONFIG_DPP */
 #endif /* DPP_H */

src/common/dpp_reconfig.c

@@ -754,4 +754,128 @@ fail:
 	goto out;
 }
 
+
+int dpp_reconfig_auth_conf_rx(struct dpp_authentication *auth, const u8 *hdr,
+			      const u8 *attr_start, size_t attr_len)
+{
+	const u8 *trans_id, *version, *wrapped_data, *i_nonce, *r_nonce,
+		*reconfig_flags;
+	u16 trans_id_len, version_len, wrapped_data_len, i_nonce_len,
+		r_nonce_len, reconfig_flags_len;
+	const u8 *addr[2];
+	size_t len[2];
+	u8 *unwrapped = NULL;
+	size_t unwrapped_len = 0;
+	struct json_token *root = NULL, *token;
+	int res = -1;
+
+	if (!auth->reconfig || auth->configurator)
+		goto fail;
+
+	wrapped_data = dpp_get_attr(attr_start, attr_len, DPP_ATTR_WRAPPED_DATA,
+				    &wrapped_data_len);
+	if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) {
+		dpp_auth_fail(auth,
+			      "Missing or invalid required Wrapped Data attribute");
+		goto fail;
+	}
+	wpa_hexdump(MSG_MSGDUMP, "DPP: Wrapped Data",
+		    wrapped_data, wrapped_data_len);
+
+	addr[0] = hdr;
+	len[0] = DPP_HDR_LEN;
+	addr[1] = attr_start;
+	len[1] = 0;
+	wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
+	wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
+	wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
+		    wrapped_data, wrapped_data_len);
+	unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE;
+	unwrapped = os_malloc(unwrapped_len);
+	if (!unwrapped)
+		goto fail;
+	if (aes_siv_decrypt(auth->ke, auth->curve->hash_len,
+			    wrapped_data, wrapped_data_len,
+			    2, addr, len, unwrapped) < 0) {
+		dpp_auth_fail(auth, "AES-SIV decryption failed");
+		goto fail;
+	}
+	wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext",
+		    unwrapped, unwrapped_len);
+
+	if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) {
+		dpp_auth_fail(auth, "Invalid attribute in unwrapped data");
+		goto fail;
+	}
+
+	trans_id = dpp_get_attr(unwrapped, unwrapped_len,
+				DPP_ATTR_TRANSACTION_ID, &trans_id_len);
+	if (!trans_id || trans_id_len != 1 ||
+	    trans_id[0] != auth->transaction_id) {
+		dpp_auth_fail(auth,
+			      "Peer did not include valid Transaction ID");
+		goto fail;
+	}
+
+	version = dpp_get_attr(unwrapped, unwrapped_len,
+			       DPP_ATTR_PROTOCOL_VERSION, &version_len);
+	if (!version || version_len < 1 || version[0] != DPP_VERSION) {
+		dpp_auth_fail(auth,
+			      "Missing or invalid Protocol Version attribute");
+		goto fail;
+	}
+
+	i_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_NONCE,
+			       &i_nonce_len);
+	if (!i_nonce || i_nonce_len != auth->curve->nonce_len ||
+	    os_memcmp(i_nonce, auth->i_nonce, i_nonce_len) != 0) {
+		dpp_auth_fail(auth, "Missing or invalid I-nonce");
+		goto fail;
+	}
+	wpa_hexdump(MSG_DEBUG, "DPP: I-nonce", i_nonce, i_nonce_len);
+
+	r_nonce = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_R_NONCE,
+			       &r_nonce_len);
+	if (!r_nonce || r_nonce_len != auth->curve->nonce_len ||
+	    os_memcmp(r_nonce, auth->r_nonce, r_nonce_len) != 0) {
+		dpp_auth_fail(auth, "Missing or invalid R-nonce");
+		goto fail;
+	}
+	wpa_hexdump(MSG_DEBUG, "DPP: R-nonce", r_nonce, r_nonce_len);
+
+	reconfig_flags = dpp_get_attr(unwrapped, unwrapped_len,
+				      DPP_ATTR_RECONFIG_FLAGS,
+				      &reconfig_flags_len);
+	if (!reconfig_flags) {
+		dpp_auth_fail(auth, "Missing or invalid Reconfig-Flags");
+		goto fail;
+	}
+	wpa_hexdump_ascii(MSG_DEBUG, "DPP: Reconfig-Flags",
+			  reconfig_flags, reconfig_flags_len);
+	root = json_parse((const char *) reconfig_flags, reconfig_flags_len);
+	if (!root) {
+		dpp_auth_fail(auth, "Could not parse Reconfig-Flags");
+		goto fail;
+	}
+	token = json_get_member(root, "connectorKey");
+	if (!token || token->type != JSON_NUMBER) {
+		dpp_auth_fail(auth, "No connectorKey in Reconfig-Flags");
+		goto fail;
+	}
+	if (token->number != DPP_CONFIG_REUSEKEY &&
+	    token->number != DPP_CONFIG_REPLACEKEY) {
+		dpp_auth_fail(auth,
+			      "Unsupported connectorKey value in Reconfig-Flags");
+		goto fail;
+	}
+	auth->reconfig_connector_key = token->number;
+
+	auth->reconfig_success = true;
+	res = 0;
+fail:
+	json_free(root);
+	bin_clear_free(unwrapped, unwrapped_len);
+	return res;
+}
+
 #endif /* CONFIG_DPP2 */

wpa_supplicant/dpp_supplicant.c

@@ -1374,7 +1374,8 @@ static void wpas_dpp_gas_resp_cb(void *ctx, const u8 *addr, u8 dialog_token,
 
 	wpa_s->dpp_gas_dialog_token = -1;
 
-	if (!auth || !auth->auth_success) {
+	if (!auth || (!auth->auth_success && !auth->reconfig_success) ||
+	    os_memcmp(addr, auth->peer_mac_addr, ETH_ALEN) != 0) {
 		wpa_printf(MSG_DEBUG, "DPP: No matching exchange in progress");
 		return;
 	}
@@ -2007,6 +2008,35 @@ wpas_dpp_rx_reconfig_auth_resp(struct wpa_supplicant *wpa_s, const u8 *src,
 	wpas_dpp_start_gas_server(wpa_s);
 }
 
+
+static void
+wpas_dpp_rx_reconfig_auth_conf(struct wpa_supplicant *wpa_s, const u8 *src,
+			       const u8 *hdr, const u8 *buf, size_t len,
+			       unsigned int freq)
+{
+	struct dpp_authentication *auth = wpa_s->dpp_auth;
+
+	wpa_printf(MSG_DEBUG, "DPP: Reconfig Authentication Confirm from "
+		   MACSTR, MAC2STR(src));
+
+	if (!auth || !auth->reconfig || auth->configurator) {
+		wpa_printf(MSG_DEBUG,
+			   "DPP: No DPP Reconfig Authentication in progress - drop");
+		return;
+	}
+
+	if (os_memcmp(src, auth->peer_mac_addr, ETH_ALEN) != 0) {
+		wpa_printf(MSG_DEBUG, "DPP: MAC address mismatch (expected "
+			   MACSTR ") - drop", MAC2STR(auth->peer_mac_addr));
+		return;
+	}
+
+	if (dpp_reconfig_auth_conf_rx(auth, hdr, buf, len) < 0)
+		return;
+
+	wpas_dpp_start_gas_client(wpa_s);
+}
+
 #endif /* CONFIG_DPP2 */
 
 
@@ -2578,6 +2608,9 @@ void wpas_dpp_rx_action(struct wpa_supplicant *wpa_s, const u8 *src,
 	case DPP_PA_RECONFIG_AUTH_RESP:
 		wpas_dpp_rx_reconfig_auth_resp(wpa_s, src, hdr, buf, len, freq);
 		break;
+	case DPP_PA_RECONFIG_AUTH_CONF:
+		wpas_dpp_rx_reconfig_auth_conf(wpa_s, src, hdr, buf, len, freq);
+		break;
 #endif /* CONFIG_DPP2 */
 	default:
 		wpa_printf(MSG_DEBUG,