Fix message type metadata leakage in websocket protocol

MyHush · Jan 11, 2020 · 6f230c9 · 6f230c9
1 parent 29d671a
commit 6f230c9
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/websockets.cpp b/src/websockets.cpp
@@ -480,7 +480,11 @@ void AppDataServer::saveNonceHex(NonceType nt, QString noncehex) {
 
 // Encrypt an outgoing message with the stored secret key.
 QString AppDataServer::encryptOutgoing(QString msg) {
-    int padding = 256;
+    // This padding size is ~50% larger than current largest
+    // message size and makes all current message types
+    // indistinguishable. If some new message type can
+    // be larger than this, the padding should probably be increased
+    int padding = 16*1024;
     qDebug() << "Encrypt msg(pad="<<padding<<")  prepad len=" << msg.length();
     if (msg.length() % padding > 0) {
         msg = msg + QString(" ").repeated(padding - (msg.length() % padding));