Allow defining additional characters for the password generator

See issue keepassxreboot#3271 for a motivation of this feature.

This patch adds an additional text input to the advanced view of the password generator.  All characters of this input field (if not empty) will be added as another group to the password generator.  The characters from the excluded field have precedence over the characters from this new field, meaning any character added to both fields will *not* appear in any generated password.  As the
characters from this new field will be added as their own group to the password generator, checking the 'Include characters from every group' checkbox will
force at least character to be chosen from the new input field.

The `PasswordGenerator` class has also been changed so that the `isValid` method returns `true` if only characters from the new input field would be used.

There is a new, simple test that covers the new feature.  While the test only uses ASCII characters, any Unicode characters can be used with the new feature.

src/browser/BrowserSettings.cpp

@@ -412,6 +412,16 @@ void BrowserSettings::setAdvancedMode(bool advancedMode)
     config()->set("generator/AdvancedMode", advancedMode);
 }
 
+QString BrowserSettings::passwordAdditionalChars()
+{
+    return config()->get("generator/AdditionalChars", PasswordGenerator::DefaultAdditionalChars).toString();
+}
+
+void BrowserSettings::setPasswordAdditionalChars(const QString& chars)
+{
+    config()->set("generator/AdditionalChars", chars);
+}
+
 QString BrowserSettings::passwordExcludedChars()
 {
     return config()->get("generator/ExcludedChars", PasswordGenerator::DefaultExcludedChars).toString();

src/browser/BrowserSettings.h

@@ -107,6 +107,8 @@ class BrowserSettings
     void setPasswordUseEASCII(bool useEASCII);
     bool advancedMode();
     void setAdvancedMode(bool advancedMode);
+    QString passwordAdditionalChars();
+    void setPasswordAdditionalChars(const QString& chars);
     QString passwordExcludedChars();
     void setPasswordExcludedChars(const QString& chars);
     int passPhraseWordCount();

src/core/PasswordGenerator.cpp

@@ -20,12 +20,14 @@
 
 #include "crypto/Random.h"
 
+const char* PasswordGenerator::DefaultAdditionalChars = "";
 const char* PasswordGenerator::DefaultExcludedChars = "";
 
 PasswordGenerator::PasswordGenerator()
     : m_length(0)
     , m_classes(nullptr)
     , m_flags(nullptr)
+    , m_additional(PasswordGenerator::DefaultAdditionalChars)
     , m_excluded(PasswordGenerator::DefaultExcludedChars)
 {
 }
@@ -53,6 +55,11 @@ void PasswordGenerator::setFlags(const GeneratorFlags& flags)
     m_flags = flags;
 }
 
+void PasswordGenerator::setAdditionalChars(const QString& chars)
+{
+    m_additional = chars;
+}
+
 void PasswordGenerator::setExcludedChars(const QString& chars)
 {
     m_excluded = chars;
@@ -107,7 +114,7 @@ QString PasswordGenerator::generatePassword() const
 
 bool PasswordGenerator::isValid() const
 {
-    if (m_classes == 0) {
+    if (m_classes == 0 && m_additional.isEmpty()) {
         return false;
     } else if (m_length == 0) {
         return false;
@@ -259,6 +266,15 @@ QVector<PasswordGroup> PasswordGenerator::passwordGroups() const
 
         passwordGroups.append(group);
     }
+    if (!m_additional.isEmpty()) {
+        PasswordGroup group;
+
+        for (auto ch : m_additional) {
+            group.append(ch);
+        }
+
+        passwordGroups.append(group);
+    }
 
     // Loop over character groups and remove excluded characters from them;
     // remove empty groups

src/core/PasswordGenerator.h

@@ -60,13 +60,15 @@ class PasswordGenerator
     void setLength(int length);
     void setCharClasses(const CharClasses& classes);
     void setFlags(const GeneratorFlags& flags);
+    void setAdditionalChars(const QString& chars);
     void setExcludedChars(const QString& chars);
 
     bool isValid() const;
 
     QString generatePassword() const;
 
     static const int DefaultLength = 16;
+    static const char* DefaultAdditionalChars;
     static const char* DefaultExcludedChars;
     static constexpr bool DefaultLower = (DefaultCharset & LowerLetters) != 0;
     static constexpr bool DefaultUpper = (DefaultCharset & UpperLetters) != 0;
@@ -90,6 +92,7 @@ class PasswordGenerator
     int m_length;
     CharClasses m_classes;
     GeneratorFlags m_flags;
+    QString m_additional;
     QString m_excluded;
 
     Q_DISABLE_COPY(PasswordGenerator)

src/gui/PasswordGeneratorWidget.cpp

@@ -48,6 +48,7 @@ PasswordGeneratorWidget::PasswordGeneratorWidget(QWidget* parent)
     connect(m_ui->editNewPassword, SIGNAL(textChanged(QString)), SLOT(updatePasswordStrength(QString)));
     connect(m_ui->buttonAdvancedMode, SIGNAL(toggled(bool)), SLOT(setAdvancedMode(bool)));
     connect(m_ui->buttonAddHex, SIGNAL(clicked()), SLOT(excludeHexChars()));
+    connect(m_ui->editAdditionalChars, SIGNAL(textChanged(QString)), SLOT(updateGenerator()));
     connect(m_ui->editExcludedChars, SIGNAL(textChanged(QString)), SLOT(updateGenerator()));
     connect(m_ui->buttonApply, SIGNAL(clicked()), SLOT(applyPassword()));
     connect(m_ui->buttonCopy, SIGNAL(clicked()), SLOT(copyPassword()));
@@ -114,6 +115,8 @@ void PasswordGeneratorWidget::loadSettings()
         config()->get("generator/SpecialChars", PasswordGenerator::DefaultSpecial).toBool());
     m_ui->checkBoxNumbersAdv->setChecked(
         config()->get("generator/Numbers", PasswordGenerator::DefaultNumbers).toBool());
+    m_ui->editAdditionalChars->setText(
+        config()->get("generator/AdditionalChars", PasswordGenerator::DefaultAdditionalChars).toString());
     m_ui->editExcludedChars->setText(
         config()->get("generator/ExcludedChars", PasswordGenerator::DefaultExcludedChars).toString());
 
@@ -315,6 +318,7 @@ void PasswordGeneratorWidget::setAdvancedMode(bool state)
 {
     if (state) {
         m_ui->simpleBar->hide();
+        m_ui->advancedContainer->show();
         m_ui->checkBoxUpperAdv->setChecked(m_ui->checkBoxUpper->isChecked());
         m_ui->checkBoxLowerAdv->setChecked(m_ui->checkBoxLower->isChecked());
         m_ui->checkBoxNumbersAdv->setChecked(m_ui->checkBoxNumbers->isChecked());
@@ -325,15 +329,9 @@ void PasswordGeneratorWidget::setAdvancedMode(bool state)
         m_ui->checkBoxDashes->setChecked(m_ui->checkBoxSpecialChars->isChecked());
         m_ui->checkBoxLogograms->setChecked(m_ui->checkBoxSpecialChars->isChecked());
         m_ui->checkBoxExtASCIIAdv->setChecked(m_ui->checkBoxExtASCII->isChecked());
-        m_ui->advancedBar->show();
-        m_ui->excludedChars->show();
-        m_ui->checkBoxExcludeAlike->show();
-        m_ui->checkBoxEnsureEvery->show();
     } else {
-        m_ui->advancedBar->hide();
-        m_ui->excludedChars->hide();
-        m_ui->checkBoxExcludeAlike->hide();
-        m_ui->checkBoxEnsureEvery->hide();
+        m_ui->simpleBar->show();
+        m_ui->advancedContainer->hide();
         m_ui->checkBoxUpper->setChecked(m_ui->checkBoxUpperAdv->isChecked());
         m_ui->checkBoxLower->setChecked(m_ui->checkBoxLowerAdv->isChecked());
         m_ui->checkBoxNumbers->setChecked(m_ui->checkBoxNumbersAdv->isChecked());
@@ -342,7 +340,6 @@ void PasswordGeneratorWidget::setAdvancedMode(bool state)
             | m_ui->checkBoxQuotes->isChecked() | m_ui->checkBoxMath->isChecked() | m_ui->checkBoxDashes->isChecked()
             | m_ui->checkBoxLogograms->isChecked());
         m_ui->checkBoxExtASCII->setChecked(m_ui->checkBoxExtASCIIAdv->isChecked());
-        m_ui->simpleBar->show();
     }
 }
 
@@ -523,8 +520,10 @@ void PasswordGeneratorWidget::updateGenerator()
         m_passwordGenerator->setCharClasses(classes);
         m_passwordGenerator->setFlags(flags);
         if (m_ui->buttonAdvancedMode->isChecked()) {
+            m_passwordGenerator->setAdditionalChars(m_ui->editAdditionalChars->text());
             m_passwordGenerator->setExcludedChars(m_ui->editExcludedChars->text());
         } else {
+            m_passwordGenerator->setAdditionalChars("");
             m_passwordGenerator->setExcludedChars("");
         }