really still wip

User/meshcore/packets/group.c

@@ -9,61 +9,64 @@
 
 #define TAG "GroupMessage"
 
-void sendGroupMessage (GroupTextMessage msg) {
-
-    msg.channelHash = persistent.aesKeys[msg.keyIndex][0];
-
-    msg.flags = 0;
-    msg.timestamp = RTC_GetCounter();
+void sendGroupMessage (const GroupTextMessage *msg) {
+    // Prepare values locally instead of modifying msg
+    uint8_t channelHash = persistent.aesKeys[msg->keyIndex][0];
+    uint8_t flags = 0;
+    int32_t timestamp = RTC_GetCounter();
 
     FrameStruct frame;
     frame.header = ROUTE_TYPE_FLOOD | PAYLOAD_TYPE_GRP_TXT | PAYLOAD_VERSION_0;
     frame.path.pathLen = 0;
     size_t offset = 0;
-    memset (frame.payload, 0, sizeof (frame.payload));
-    frame.payload[offset++] = msg.channelHash;
+    frame.payload[offset++] = channelHash;
 
-    uint8_t cipherBuf[176];
-    size_t offset2 = 0;
-    memcpy (cipherBuf, (const void *)&(msg.timestamp), 4);
-    offset2 += 4;
-    cipherBuf[offset2++] = msg.flags;
-    size_t textSize = offset2 + strlen ((const char *)msg.text);
-    if (textSize > 175) {
-        textSize = 175;
+    // Build encryption buffer directly on stack (no extra large buffer)
+    uint8_t buf[180];  // enough for timestamp + flags + text
+    size_t buf_offset = 0;
+
+    memcpy (buf + buf_offset, &timestamp, sizeof (timestamp));
+    buf_offset += sizeof (timestamp);
+
+    buf[buf_offset++] = flags;
+
+    size_t textLen = strlen ((const char *)msg->text);
+    if (buf_offset + textLen > sizeof (buf)) {
+        textLen = sizeof (buf) - buf_offset;
     }
-    memcpy (cipherBuf + offset2, msg.text, textSize);
-    offset2 += textSize;
+    memcpy (buf + buf_offset, msg->text, textLen);
+    buf_offset += textLen;
 
+    hexdump ("TxDumpDec", buf, buf_offset);
+
+    // Encrypt and MAC directly into frame payload after channelHash
     size_t olen = 0;
-    hexdump ("TxDumpDec", cipherBuf, offset2);
-    encrypt_then_mac (&(persistent.aesKeys[msg.keyIndex][1]), 16, cipherBuf, offset2, &(frame.payload[offset]), &olen);
+    encrypt_then_mac (&persistent.aesKeys[msg->keyIndex][1], 16, buf, buf_offset, &frame.payload[offset], &olen);
 
-    frame.payloadLen = olen + 1;
+    frame.payloadLen = olen + 1;  // +1 for channelHash
 
-    sendFrame (frame);
-    return;
+    LoRaTransmit (&frame);
 }
 
 void makeSendGroupMessage (char *txt, uint8_t keyIndex) {
     GroupTextMessage msg;
-    strcpy((char *) msg.text, persistent.nodeName);
+    strcpy ((char *)msg.text, persistent.nodeName);
     strcat ((char *)msg.text, ": ");
     strcat ((char *)msg.text, txt);
     msg.keyIndex = keyIndex;
-    sendGroupMessage (msg);
+    sendGroupMessage (&msg);
     return;
 }
 
-GroupTextMessage decodeGroupMessage (FrameStruct frame) {
+void decodeGroupMessage (const FrameStruct *frame) {
     GroupTextMessage msg;
     memset (&msg, 0, sizeof (msg));
-    if ((frame.header & PAYLOAD_TYPE_MASK) != PAYLOAD_TYPE_GRP_TXT) {
-        ESP_LOGW (TAG, "Not a group text");
-        return msg;
+    if ((frame->header & PAYLOAD_TYPE_MASK) != PAYLOAD_TYPE_GRP_TXT) {
+        MESH_LOGW (TAG, "Not a group text");
+        return;
     }
     unsigned char index = 0;
-    msg.channelHash = frame.payload[index++];
+    msg.channelHash = frame->payload[index++];
     unsigned char tmp[184];
 
 
@@ -71,27 +74,27 @@ GroupTextMessage decodeGroupMessage (FrameStruct frame) {
     for (unsigned char i = 0; i < AESKeyCount; i++) {
 
         if (msg.channelHash != persistent.aesKeys[i][0]) {
-            ESP_LOGW (TAG, "Hash %d does not equal %d", persistent.aesKeys[i][0], msg.channelHash);
+            MESH_LOGW (TAG, "Hash %d does not equal %d", persistent.aesKeys[i][0], msg.channelHash);
             continue;
         }
 
-        ESP_LOGW (TAG, "Hash does equal %d", msg.channelHash);
+        MESH_LOGW (TAG, "Hash does equal %d", msg.channelHash);
 
-        if (mac_then_decrypt (persistent.aesKeys[i] + 1, 16, frame.payload + index, frame.payloadLen - index, tmp) != 0) {
-            ESP_LOGW (TAG, "HMAC failed on grouphash key %d not matching %d", persistent.aesKeys[i][0], msg.channelHash);
+        if (mac_then_decrypt (persistent.aesKeys[i] + 1, 16, frame->payload + index, frame->payloadLen - index, tmp) != 0) {
+            MESH_LOGW (TAG, "HMAC failed on grouphash key %d not matching %d", persistent.aesKeys[i][0], msg.channelHash);
             continue;
         }
-        hexdump ("RxDumpDec", tmp, frame.payloadLen - index);
+        hexdump ("RxDumpDec", tmp, frame->payloadLen - index);
         decrypted = 1;
         break;
     }
 
 
     if (!decrypted) {
-        return msg;
+        return;
     }
 
-    unsigned char plaintextLen = frame.payloadLen - index;
+    unsigned char plaintextLen = frame->payloadLen - index;
     index = 0;
 
     memcpy (&msg.timestamp, tmp + index, 4);
@@ -99,10 +102,11 @@ GroupTextMessage decodeGroupMessage (FrameStruct frame) {
     msg.flags = tmp[index++];
 
     memcpy (msg.text, tmp + index, plaintextLen - index);
-    return msg;
+
+    printGroupMessage (&msg);
 }
 
-void printGroupMessage (GroupTextMessage msg) {
-    printf ("Message with channel hash %d, flags %d: %s\n", msg.channelHash,
-            msg.flags, msg.text);
+void printGroupMessage (const GroupTextMessage *msg) {
+    printf ("Message with channel hash %d, flags %d: %s\n", msg->channelHash,
+            msg->flags, msg->text);
 }