bool loadConf_Secrets()  // from EEPROM or File System, with or without encryption
{
    bool _isEncrypted = confCheckEncrypted();

    #ifdef ENABLE_FEATURE_SECRETS_ENCRYPTION
    struct confDataSecrets
    {
      char WiFiPW1[64];
      char WiFiPW2[64];
      char WiFiAPModePassword[64];
      char http_token[31];
      char http_user[31];
      char http_pass[31];
      char http_user1[31];
      char http_pass1[31];
      char http_user2[31];
      char http_pass2[31];
      char mqtt_user[31];
      char mqtt_pass[31];
      // --- 471 bytes
      char spare[23];
      // --- 494 bytes + 2 bytes size information 
      // in EEPROM before the actual data => 512 bytes
    } _confSecrets_encrypted;
    #endif

    bool _success = false;
    
    #ifdef STORE_SECRETS_IN_EEPROM
        uint16_t _size;
        EEPROM.begin(EEPROM_SIZE);

        EEPROM.get(EEPROM_STARTADDR_SECRETS, _size);

        if( (_size + EEPROM_STARTADDR_SECRETS + 2) <= EEPROM_SIZE ) {
            if(_size == sizeof(confSecrets)) {
                // size of stored data is stored in first 2 bytes
                // as it matches sizeof struct - proceed

                // restore complete confSecrets struct from EEPROM
                #ifdef ENABLE_FEATURE_SECRETS_ENCRYPTION
                    EEPROM.get(EEPROM_STARTADDR_SECRETS + 2, _confSecrets_encrypted);
                #else
                    EEPROM.get(EEPROM_STARTADDR_SECRETS + 2, confSecrets);
                #endif

                EEPROM.end(); 

                snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredSecrets_EEPROM, _size);
                sendLog(logBuf);

                // // size in EEPROM is smaller than the struct
                // // so there was a program extension/update
                // // --> fill up rest of struct with 0x00 
                // //     as it will now contain most likely all 0xFF
                // //     from previously unused EEPROM
                // if(_size < sizeof(confSecrets)) {
                //     snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredSecrets_fillUp_EEPROM, sizeof(confSecrets) - _size);
                //     sendLog(logBuf);
                //     uint8_t _zero = '\0';
                //     for(uint16_t _i = 0; _i < sizeof(confSecrets); _i++) {
                //         if(_i >= (_size - 1)) {
                //             memcpy(&confSecrets + _i, &_zero, 1);
                //         }
                //     }
                // }
                //  --> untested, dont use this

                _success = true;
            }
            else {
                EEPROM.end(); 
                snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_errorRestoreSecrets_EEPROM, _size, sizeof(confSecrets));
                sendLog(logBuf);
                _success = false;
            }
        }
        else {
            EEPROM.end(); 
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_errorRestoreSecretsExceedSize_EEPROM);
            sendLog(logBuf);
            _success = false;
        }
    
    #else // STORE_SECRETS_IN_EEPROM is not defined - use file on LittleFS

        char configFileName[] = "/confSecrets";
        if (LittleFS.exists(configFileName)) {
            File configFile = LittleFS.open(configFileName, "r");
            if (!configFile) {
                snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
                sendLog(logBuf);
                _success = false;
            }
            else
            {
                #ifdef ENABLE_FEATURE_SECRETS_ENCRYPTION
                    configFile.read((byte *)&_confSecrets_encrypted, sizeof(_confSecrets_encrypted));
                #else
                    configFile.read((byte *)&confSecrets, sizeof(confSecrets));
                #endif

                snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
                sendLog(logBuf);

                configFile.close();
                _success = true;
            }
        }
        else
        {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
            sendLog(logBuf);
            _success = false;
        }

    #endif


    if(_success) {
        #ifdef ENABLE_FEATURE_SECRETS_ENCRYPTION
            if(_isEncrypted) {
                XORENC(_confSecrets_encrypted.WiFiPW1, encKey);
                XORENC(_confSecrets_encrypted.WiFiPW2, encKey);
                XORENC(_confSecrets_encrypted.WiFiAPModePassword, encKey);
                XORENC(_confSecrets_encrypted.http_token, encKey);
                XORENC(_confSecrets_encrypted.http_user, encKey);
                XORENC(_confSecrets_encrypted.http_pass, encKey); 
                XORENC(_confSecrets_encrypted.http_user1, encKey);
                XORENC(_confSecrets_encrypted.http_pass1, encKey);
                XORENC(_confSecrets_encrypted.http_user2, encKey);
                XORENC(_confSecrets_encrypted.http_pass2, encKey);
                XORENC(_confSecrets_encrypted.mqtt_user, encKey); 
                XORENC(_confSecrets_encrypted.mqtt_pass, encKey); 
                snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_encryptedSecretsLoaded);
                sendLog(logBuf);
            }
            memcpy(&confSecrets, &_confSecrets_encrypted, sizeof(confSecrets));
        

            #ifdef DEBUG_SECRETS_ENCRYPTION
            if(_isEncrypted) {
                Serial.println(F("Secrets UNencrypted:"));
                Serial.print(F("WiFiPW1:    ")); Serial.println(confSecrets.WiFiPW1);
                Serial.print(F("WiFiPW2:    ")); Serial.println(confSecrets.WiFiPW2);
                Serial.print(F("WiFiAPPW:   ")); Serial.println(confSecrets.WiFiAPModePassword);
                Serial.print(F("http_token: ")); Serial.println(confSecrets.http_token);
                Serial.print(F("http_user:  ")); Serial.println(confSecrets.http_user);
                Serial.print(F("http_pass:  ")); Serial.println(confSecrets.http_pass);
                Serial.print(F("http_user1: ")); Serial.println(confSecrets.http_user1);
                Serial.print(F("http_pass1: ")); Serial.println(confSecrets.http_pass1);
                Serial.print(F("http_user2: ")); Serial.println(confSecrets.http_user2);
                Serial.print(F("http_pass2: ")); Serial.println(confSecrets.http_pass2);
                Serial.print(F("mqtt_user:  ")); Serial.println(confSecrets.mqtt_user);
                Serial.print(F("mqtt_pass:  ")); Serial.println(confSecrets.mqtt_pass);
                Serial.println(F("Secrets Encrypted:"));
                Serial.print(F("WiFiPW1:    ")); Serial.println(_confSecrets_encrypted.WiFiPW1);
                Serial.print(F("WiFiPW2:    ")); Serial.println(_confSecrets_encrypted.WiFiPW2);
                Serial.print(F("WiFiAPPW:   ")); Serial.println(_confSecrets_encrypted.WiFiAPModePassword);
                Serial.print(F("http_token: ")); Serial.println(_confSecrets_encrypted.http_token);
                Serial.print(F("http_user:  ")); Serial.println(_confSecrets_encrypted.http_user);
                Serial.print(F("http_pass:  ")); Serial.println(_confSecrets_encrypted.http_pass);
                Serial.print(F("http_user1: ")); Serial.println(_confSecrets_encrypted.http_user1);
                Serial.print(F("http_pass1: ")); Serial.println(_confSecrets_encrypted.http_pass1);
                Serial.print(F("http_user2: ")); Serial.println(_confSecrets_encrypted.http_user2);
                Serial.print(F("http_pass2: ")); Serial.println(_confSecrets_encrypted.http_pass2);
                Serial.print(F("mqtt_user:  ")); Serial.println(_confSecrets_encrypted.mqtt_user);
                Serial.print(F("mqtt_pass:  ")); Serial.println(_confSecrets_encrypted.mqtt_pass);
                Serial.println();
            }
            #endif
        #endif

        return true;
    }
    else {
        return false;
    }
    
} // loadConf_Secrets




bool loadConf_DevWiFi()
{
    char configFileName[] = "/confDevWiFi";
    if (LittleFS.exists(configFileName)) {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confDevWiFi, sizeof(confDevWiFi));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_DevWiFi



bool loadConf_Web()
{
    //char configFileName[] = "/confWeb.json";
    char configFileName[] = "/confWeb";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confWeb, sizeof(confWeb));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Web



bool loadConf_Mqtt()
{
    char configFileName[] = "/confMqtt";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confMqtt, sizeof(confMqtt));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Mqtt


#ifdef FIRMWARE_VARIANT_THERMOSTAT
bool loadConf_Therm()
{
    char configFileName[] = "/confTherm";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confTherm, sizeof(confTherm));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Therm
#endif


bool loadConf_Add()
{
    char configFileName[] = "/confAdd";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confAdd, sizeof(confAdd));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Add



#ifdef ENABLE_FEATURE_NTP_TIME
bool loadConf_Time()
{
    char configFileName[] = "/confTime";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confTime, sizeof(confTime));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Time
#endif



bool loadConf_Log()
{
    char configFileName[] = "/confLog";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confLog, sizeof(confLog));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Log



bool loadConf_Sens()
{
    
    char configFileName[] = "/confSens";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confSens, sizeof(confSens));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Sens



#ifdef FIRMWARE_VARIANT_HEATCONTROL
bool loadConf_Heatc()
{
    char configFileName[] = "/confHeatc";
    if (LittleFS.exists(configFileName))
    {
        File configFile = LittleFS.open(configFileName, "r");
        if (!configFile) {
            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_ErrorOpenFile, configFileName);
            sendLog(logBuf);
            return false;
        }
        else
        {
            configFile.read((byte *)&confHeatc, sizeof(confHeatc));

            snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_restoredConf, configFileName, configFile.size());
            sendLog(logBuf);

            configFile.close();
            return true;
        }
    }
    else
    {
        snprintf_P(logBuf, LOG_BUFFER_SIZE, PGMStr_loadConf_FileNotExist, configFileName);
        sendLog(logBuf);
        return false;
    }
} // loadConf_Heatc
#endif