Resolve some typos

Use nullptr over NULL
Fix confusing regexp
Fix issue with non-compliant JWT encoding

src/APSettingsService.cpp

@@ -46,7 +46,7 @@ void APSettingsService::stopAP() {
     Serial.println("Stopping captive portal");
     _dnsServer->stop();
     delete _dnsServer;
-    _dnsServer = NULL;
+    _dnsServer = nullptr;
   }
   Serial.println("Stopping software access point");
   WiFi.softAPdisconnect(true);

src/ArduinoJsonJWT.cpp

@@ -69,14 +69,14 @@ void ArduinoJsonJWT::parseJWT(String jwt, JsonDocument &jsonDocument) {
     return;
   }
   // must have signature of correct length
-  int signatureDelimieterIndex = jwt.length() - JWT_SIG_SIZE - 1;
-  if (jwt.lastIndexOf('.') != signatureDelimieterIndex) {
+  int signatureDelimiterIndex = jwt.length() - JWT_SIG_SIZE - 1;
+  if (jwt.lastIndexOf('.') != signatureDelimiterIndex) {
     return;
   }
 
   // signature must be correct
-  String signature = jwt.substring(signatureDelimieterIndex + 1);
-  jwt = jwt.substring(0, signatureDelimieterIndex);
+  String signature = jwt.substring(signatureDelimiterIndex + 1);
+  jwt = jwt.substring(0, signatureDelimiterIndex);
   if (sign(jwt) != signature){
     return;
   }
@@ -115,7 +115,7 @@ String ArduinoJsonJWT::encode(const char *cstr, int inputLen) {
   String value = String(buffer);
 
   // remove padding and convert to URL safe form
-  while (value.charAt(value.length() - 1) == '='){
+  while (value.length() > 0 && value.charAt(value.length() - 1) == '='){
     value.remove(value.length() - 1);
   }
   value.replace('+', '-');

src/AsyncArduinoJson6.h

@@ -109,7 +109,7 @@ public:
   }
   virtual void handleRequest(AsyncWebServerRequest *request) override final {
     if(_onRequest) {
-      if (request->_tempObject != NULL) {
+      if (request->_tempObject != nullptr) {
         DynamicJsonDocument _jsonDocument(_maxContentLength);
         DeserializationError err = deserializeJson(_jsonDocument, (uint8_t*)(request->_tempObject));
         if (err == DeserializationError::Ok) {
@@ -127,10 +127,10 @@ public:
   virtual void handleBody(AsyncWebServerRequest *request, uint8_t *data, size_t len, size_t index, size_t total) override final {
     if (_onRequest) {
       _contentLength = total;
-      if (total > 0 && request->_tempObject == NULL && total < _maxContentLength) {
+      if (total > 0 && request->_tempObject == nullptr && total < _maxContentLength) {
         request->_tempObject = malloc(total);
       }
-      if (request->_tempObject != NULL) {
+      if (request->_tempObject != nullptr) {
         memcpy((uint8_t*)(request->_tempObject) + index, data, len);
       }
     }

src/AsyncJsonWebHandler.h

@@ -31,7 +31,7 @@ class AsyncJsonWebHandler: public AsyncWebHandler {
 
     AsyncJsonWebHandler() :      
       _method(HTTP_POST|HTTP_PUT|HTTP_PATCH),
-      _onRequest(NULL),
+      _onRequest(nullptr),
       _maxContentLength(ASYNC_JSON_REQUEST_DEFAULT_MAX_SIZE),
       _uri() {}
 

src/OTASettingsService.cpp

@@ -40,7 +40,7 @@ void OTASettingsService::writeToJsonObject(JsonObject& root) {
 void OTASettingsService::configureArduinoOTA() {
   if (_arduinoOTA){
     delete _arduinoOTA;
-    _arduinoOTA = NULL;
+    _arduinoOTA = nullptr;
   }
   if (_enabled) {
     Serial.println("Starting OTA Update Service");

src/SecurityManager.h

@@ -37,11 +37,9 @@ class Authentication {
     boolean _authenticated;
   public:
     Authentication(User& user): _user(new User(user)), _authenticated(true) {}
-    Authentication() : _user(NULL), _authenticated(false) {}  
+    Authentication() : _user(nullptr), _authenticated(false) {}  
     ~Authentication() {
-      if (_user != NULL){
-        delete(_user);
-      }      
+      delete(_user);   
     }
     User* getUser() {
       return _user;