Limit PWS fields input according to UTF8 binary length #131

Signed-off-by: Szczepan Zalega <szczepan@nitrokey.com>

src/ui/mainwindow.cpp

@@ -4148,20 +4148,25 @@ void MainWindow::on_radioButton_toggled(bool checked) {
 }
 
 void MainWindow::on_PWS_EditSlotName_textEdited(const QString &arg1) {
-  static QString valid_slotname;
   int chars_left = PWS_SLOTNAME_LENGTH - strlen(arg1.toUtf8());
   QString t = QString("%1").arg(chars_left);
   ui->l_c_name->setText(t);
+  ui->PWS_EditSlotName->setValidator(
+      new utf8FieldLengthValidator(PWS_SLOTNAME_LENGTH, ui->PWS_EditSlotName));
 }
 
 void MainWindow::on_PWS_EditLoginName_textEdited(const QString &arg1) {
   int chars_left = PWS_LOGINNAME_LENGTH - strlen(arg1.toUtf8());
   QString t = QString("%1").arg(chars_left);
   ui->l_c_login->setText(t);
+  ui->PWS_EditLoginName->setValidator(
+      new utf8FieldLengthValidator(PWS_LOGINNAME_LENGTH, ui->PWS_EditLoginName));
 }
 
 void MainWindow::on_PWS_EditPassword_textEdited(const QString &arg1) {
   int chars_left = PWS_PASSWORD_LENGTH - strlen(arg1.toUtf8());
   QString t = QString("%1").arg(chars_left);
   ui->l_c_password->setText(t);
+  ui->PWS_EditPassword->setValidator(
+      new utf8FieldLengthValidator(PWS_PASSWORD_LENGTH, ui->PWS_EditPassword));
 }

src/ui/mainwindow.h

@@ -24,6 +24,8 @@
 #include "device.h"
 #include <QMainWindow>
 #include <QSystemTrayIcon>
+#include <QValidator>
+
 #include <climits>
 
 #define uint64_t unsigned long long
@@ -312,4 +314,26 @@ private slots:
   void on_PWS_EditPassword_textEdited(const QString &arg1);
 };
 
+class utf8FieldLengthValidator : public QValidator {
+  Q_OBJECT
+private:
+  int field_max_length;
+
+public:
+  explicit utf8FieldLengthValidator(QObject *parent = 0);
+  explicit utf8FieldLengthValidator(int _field_max_length, QObject *parent = 0)
+      : QValidator(parent), field_max_length(_field_max_length) {}
+  virtual State validate(QString &input, int &) const {
+    if (input.isEmpty())
+      return Invalid;
+
+    int chars_left = field_max_length - strlen(input.toUtf8());
+
+    if (chars_left >= 0) {
+      return Acceptable;
+    }
+    return Invalid;
+  }
+};
+
 #endif // MAINWINDOW_H