Add config option 'allow_unsafe_username_chars'

Wiebe Cazemier
1 parent 5d72070e
Showing 5 changed files with 49 additions and 4 deletions
configfileparser.cpp
mqttpacket.cpp
settings.h
utils.cpp
utils.h
@@ -41,6 +41,7 @@ ConfigFileParser::ConfigFileParser(const std::string &amp;path) :
     validKeys.insert("auth_plugin");
     validKeys.insert("log_file");
     validKeys.insert("allow_unsafe_clientid_chars");
+    validKeys.insert("allow_unsafe_username_chars");
     validKeys.insert("client_initial_buffer_size");
     validKeys.insert("max_packet_size");
  
@@ -221,6 +222,12 @@ void ConfigFileParser::loadFile(bool test)
                     tmpSettings->allowUnsafeClientidChars = tmp;
                 }
  
+                if (key == "allow_unsafe_username_chars")
+                {
+                    bool tmp = stringTruthiness(value);
+                    tmpSettings->allowUnsafeUsernameChars = tmp;
+                }
+
                 if (key == "client_initial_buffer_size")
                 {
                     int newVal = std::stoi(value);
@@ -232,9 +232,9 @@ void MqttPacket::handleConnect()
         bool validClientId = true;
  
         // Check for wildcard chars in case the client_id ever appears in topics.
-        if (!settings.allowUnsafeClientidChars && (strContains(client_id, "+") || strContains(client_id, "#")))
+        if (!settings.allowUnsafeClientidChars && containsDangerousCharacters(client_id))
         {
-            logger->logf(LOG_ERR, "ClientID '%s' has + or # in the id and 'allow_unsafe_clientid_chars' is false:", client_id.c_str());
+            logger->logf(LOG_ERR, "ClientID '%s' has + or # in the id and 'allow_unsafe_clientid_chars' is false.", client_id.c_str());
             validClientId = false;
         }
         else if (!clean_session && client_id.empty())
@@ -266,7 +266,21 @@ void MqttPacket::handleConnect()
         sender->setClientProperties(protocolVersion, client_id, username, true, keep_alive, clean_session);
         sender->setWill(will_topic, will_payload, will_retain, will_qos);
  
-        if (sender->getThreadData()->authPlugin.unPwdCheck(username, password) == AuthResult::success)
+        bool accessGranted = false;
+        std::string denyLogMsg;
+
+        if (!settings.allowUnsafeUsernameChars && containsDangerousCharacters(username))
+        {
+            denyLogMsg = formatString("Username '%s' has + or # in the id and 'allow_unsafe_username_chars' is false.", username.c_str());
+            sender->setDisconnectReason("Invalid username character");
+            accessGranted = false;
+        }
+        else if (sender->getThreadData()->authPlugin.unPwdCheck(username, password) == AuthResult::success)
+        {
+            accessGranted = true;
+        }
+
+        if (accessGranted)
         {
             bool sessionPresent = protocolVersion >= ProtocolVersion::Mqtt311 && !clean_session && subscriptionStore->sessionPresent(client_id);
             subscriptionStore->registerClientAndKickExistingOne(sender);
@@ -284,7 +298,10 @@ void MqttPacket::handleConnect()
             sender->setDisconnectReason("Access denied");
             sender->setReadyForDisconnect();
             sender->writeMqttPacket(response);
-            logger->logf(LOG_NOTICE, "User '%s' access denied", username.c_str());
+            if (!denyLogMsg.empty())
+                logger->logf(LOG_NOTICE, denyLogMsg.c_str());
+            else
+                logger->logf(LOG_NOTICE, "User '%s' access denied", username.c_str());
         }
     }
     else
@@ -18,6 +18,7 @@ public:
     std::string authPluginPath;
     std::string logPath;
     bool allowUnsafeClientidChars = false;
+    bool allowUnsafeUsernameChars = false;
     int clientInitialBufferSize = 1024; // Must be power of 2
     int maxPacketSize = 268435461; // 256 MB + 5
     std::list<std::shared_ptr<Listener>> listeners; // Default one is created later, when none are defined.
@@ -137,6 +137,25 @@ bool isValidPublishPath(const std::string &amp;s)
     return true;
 }
  
+bool containsDangerousCharacters(const std::string &s)
+{
+    if (s.empty())
+        return false;
+
+    for (const char c : s)
+    {
+        switch(c)
+        {
+        case '#':
+            return  true;
+        case '+':
+            return  true;
+        }
+    }
+
+    return false;
+}
+
 std::vector<std::string> splitToVector(const std::string &input, const char sep, size_t max, bool keep_empty_parts)
 {
     std::vector<std::string> list;
@@ -34,6 +34,7 @@ bool isValidUtf8(const std::string &amp;s);
 bool strContains(const std::string &s, const std::string &needle);
  
 bool isValidPublishPath(const std::string &s);
+bool containsDangerousCharacters(const std::string &s);
  
 void ltrim(std::string &s);
 void rtrim(std::string &s);