Validate edit locally token before sending to server

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

src/gui/folderman.cpp

@@ -27,6 +27,8 @@
 #include <pushnotifications.h>
 #include <syncengine.h>
 
+#include <iostream>
+
 #ifdef Q_OS_MAC
 #include <CoreServices/CoreServices.h>
 #endif
@@ -1498,6 +1500,17 @@ void FolderMan::editFileLocally(const QString &userId, const QString &relPath, c
         showError(accountFound, tr("Could not find a folder to sync."), relPath);
         return;
     }
+
+    // Token is an alphanumeric string 128 chars long.
+    // Ensure that is what we received and what we are sending to the server.
+    const QRegularExpression tokenRegex("^[a-zA-Z0-9]{128}$");
+    const auto regexMatch = tokenRegex.match(token);
+
+         // Means invalid token type received, be cautious with bad token
+    if(!regexMatch.hasMatch()) {
+        showError(accountFound, tr("Invalid token received:"), token);
+        return;
+    }
 
     const auto relPathSplit = relPath.split(QLatin1Char('/'));
     if (relPathSplit.size() > 0) {