Check publish paths

Wiebe Cazemier
1 parent 52cdff03
Showing 3 changed files with 24 additions and 1 deletions
mqttpacket.cpp
utils.cpp
utils.h
@@ -4,6 +4,8 @@
 #include <list>
 #include <cassert>
+#include "utils.h"
+
 RemainingLength::RemainingLength()
 {
     memset(bytes, 0, 4);
@@ -254,9 +256,14 @@ void MqttPacket::handlePublish(std::shared_ptr&lt;SubscriptionStore&gt; &amp;subscriptionS
     if (qos == 3)
         throw ProtocolError("QoS 3 is a protocol violation.");
-    // TODO: validate UTF8.
     std::string topic(readBytes(variable_header_length), variable_header_length);
+    if (!isValidUtf8(topic) || !isValidPublishPath(topic))
+    {
+        std::cerr << "Client " << sender->repr() << " sent topic with wildcards or invalid UTF8. Ignoring.";
+        return;
+    }
+
     if (qos)
     {
         throw ProtocolError("Qos not implemented.");
@@ -111,3 +111,17 @@ bool strContains(const std::string &amp;s, const std::string &amp;needle)
 {
     return s.find(needle) != std::string::npos;
 }
+
+bool isValidPublishPath(const std::string &s)
+{
+    if (s.empty())
+        return false;
+
+    for (const char c : s)
+    {
+        if (c == '#' || c == '+')
+            return false;
+    }
+
+    return true;
+}
@@ -27,4 +27,6 @@ bool isValidUtf8(const std::string &amp;s);
 bool strContains(const std::string &s, const std::string &needle);
+bool isValidPublishPath(const std::string &s);
+
 #endif // UTILS_H