From 018880490904469ab696292363211584184c7495 Mon Sep 17 00:00:00 2001
From: Ingo Fischer <github@fischer-ka.de>
Date: Tue, 8 Nov 2022 10:19:08 +0100
Subject: [PATCH] cleanup some code and add 3.2 support (adresses #234)

---
 index.js              |  7 ++++---
 lib/cipher.js         |  4 ++--
 lib/message-parser.js | 23 ++++++++++++++---------
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/index.js b/index.js
index 0da1a6d..be0410a 100644
--- a/index.js
+++ b/index.js
@@ -57,6 +57,7 @@ class TuyaDevice extends EventEmitter {
     super();
 
     // Set device to user-passed options
+    version = version.toString();
     this.device = {ip, port, id, gwID, key, productKey, version};
     this.globalOptions = {
       issueGetOnConnect,
@@ -648,7 +649,7 @@ class TuyaDevice extends EventEmitter {
           const buffer = this.device.parser.encode({
             data: this._tmpLocalKey,
             encrypted: true,
-            commandByte: CommandType.BIND,
+            commandByte: CommandType.SESS_KEY_NEG_START,
             sequenceN: ++this._currentSequenceN
           });
 
@@ -675,7 +676,7 @@ class TuyaDevice extends EventEmitter {
     clearTimeout(this._sendTimeout);
 
     // Protocol 3.4 - Response to Msg 0x03
-    if (packet.commandByte === CommandType.RENAME_GW) {
+    if (packet.commandByte === CommandType.SESS_KEY_NEG_RES) {
       if (!this.connectPromise) {
         debug('Protocol 3.4: Ignore Key exchange message because no connection in progress.');
         return;
@@ -703,7 +704,7 @@ class TuyaDevice extends EventEmitter {
       const buffer = this.device.parser.encode({
         data: this.device.parser.cipher.hmac(this._tmpRemoteKey),
         encrypted: true,
-        commandByte: CommandType.RENAME_DEVICE,
+        commandByte: CommandType.SESS_KEY_NEG_FINISH,
         sequenceN: ++this._currentSequenceN
       });
 
diff --git a/lib/cipher.js b/lib/cipher.js
index 3501770..01c2b99 100644
--- a/lib/cipher.js
+++ b/lib/cipher.js
@@ -107,8 +107,8 @@ class TuyaCipher {
     let format = 'buffer';
 
     if (data.indexOf(this.version) === 0) {
-      if (this.version === '3.3') {
-        // Remove 3.3 header
+      if (this.version === '3.3' || this.version === '3.2') {
+        // Remove 3.3/3.2 header
         data = data.slice(15);
       } else {
         // Data has version number and is encoded in base64
diff --git a/lib/message-parser.js b/lib/message-parser.js
index f6ee3fa..eab4d6c 100644
--- a/lib/message-parser.js
+++ b/lib/message-parser.js
@@ -6,6 +6,7 @@ const HEADER_SIZE = 16;
 /**
  * Human-readable definitions
  * of command bytes.
+ * See also https://github.com/tuya/tuya-iotos-embeded-sdk-wifi-ble-bk7231n/blob/master/sdk/include/lan_protocol.h
  * @readonly
  * @private
  */
@@ -13,9 +14,12 @@ const CommandType = {
   UDP: 0,
   AP_CONFIG: 1,
   ACTIVE: 2,
-  BIND: 3,
-  RENAME_GW: 4,
-  RENAME_DEVICE: 5,
+  BIND: 3, // ?? leave in for backward compatibility
+  SESS_KEY_NEG_START: 3, // negotiate session key
+  RENAME_GW: 4, // ?? leave in for backward compatibility
+  SESS_KEY_NEG_RES: 4, // negotiate session key response
+  RENAME_DEVICE: 5,  // ?? leave in for backward compatibility
+  SESS_KEY_NEG_FINISH: 5,// finalize session key negotiation
   UNBIND: 6,
   CONTROL: 7,
   STATUS: 8,
@@ -27,10 +31,11 @@ const CommandType = {
   ENABLE_WIFI: 14,
   DP_QUERY_NEW: 16,
   SCENE_EXECUTE: 17,
-  DP_REFRESH: 18,
+  DP_REFRESH: 18, // Request refresh of DPS  UPDATEDPS / LAN_QUERY_DP
   UDP_NEW: 19,
   AP_CONFIG_NEW: 20,
-  UDP_NEW_34: 35,
+  BOARDCAST_LPV34: 35,
+  LAN_EXT_STREAM: 40,
   LAN_GW_ACTIVE: 240,
   LAN_SUB_DEV_REQUEST: 241,
   LAN_DELETE_SUB_DEV: 242,
@@ -294,8 +299,8 @@ class MessageParser {
     // Construct payload
     let payload = options.data;
 
-    // Protocol 3.3 is always encrypted
-    if (this.version === '3.3') {
+    // Protocol 3.3 and 3.2 is always encrypted
+    if (this.version === '3.3' || this.version === '3.2') {
       // Encrypt data
       payload = this.cipher.encrypt({
         data: payload,
@@ -365,8 +370,8 @@ class MessageParser {
     if (options.commandByte !== CommandType.DP_QUERY &&
         options.commandByte !== CommandType.HEART_BEAT &&
         options.commandByte !== CommandType.DP_QUERY_NEW &&
-        options.commandByte !== CommandType.BIND &&
-        options.commandByte !== CommandType.RENAME_DEVICE &&
+        options.commandByte !== CommandType.SESS_KEY_NEG_START &&
+        options.commandByte !== CommandType.SESS_KEY_NEG_FINISH &&
         options.commandByte !== CommandType.DP_REFRESH) {
       // Add 3.4 header
       // check this: mqc_very_pcmcd_mcd(int a1, unsigned int a2)