Add function param/return types, fix a lot more phpstorm complaints

24 files changed, 490 insertions, 487 deletions

diff --git a/modules-available/sysconfig/addconfig.inc.php b/modules-available/sysconfig/addconfig.inc.php
index 8df700f9..27af31e8 100644
--- a/modules-available/sysconfig/addconfig.inc.php
+++ b/modules-available/sysconfig/addconfig.inc.php
@@ -9,21 +9,17 @@ abstract class AddConfig_Base
 
 	/**
 	 * Holds the instance for the currently executing step
-	 * @var \AddConfig_Base
+	 * @var AddConfig_Base
 	 */
-	private static $instance = false;
+	private static $instance = null;
 	
 	/**
 	 * Config being edited (if any)
-	 * @var \ConfigTgz
+	 * @var ?ConfigTgz
 	 */
-	protected $edit = false;
+	protected $edit = null;
 
-	/**
-	 * 
-	 * @param string $step
-	 */
-	public static function setStep($step)
+	public static function setStep(string $step)
 	{
 		if (empty($step) || !class_exists($step) || get_parent_class($step) !== 'AddConfig_Base') {
 			Message::addError('invalid-action', $step);
@@ -32,18 +28,12 @@ abstract class AddConfig_Base
 		self::$instance = new $step();
 		if (($editId = Request::any('edit', 0, 'int')) !== 0) {
 			self::$instance->edit = ConfigTgz::get($editId);
-			if (self::$instance->edit === false)
+			if (self::$instance->edit === null)
 				ErrorHandler::traceError('Invalid config id for editing');
 			Util::addRedirectParam('edit', self::$instance->edit->id());
 		}
 	}
 
-	protected function tmError()
-	{
-		Message::addError('main.taskmanager-error');
-		Util::redirect('?do=SysConfig');
-	}
-
 	/**
 	 * Called before any HTML rendering happens, so you can
 	 * prepare stuff, validate input, and optionally redirect
@@ -73,7 +63,7 @@ abstract class AddConfig_Base
 	
 	public static function preprocess()
 	{
-		if (self::$instance === false) {
+		if (self::$instance === null) {
 			ErrorHandler::traceError('No step instance yet');
 		}
 		self::$instance->preprocessInternal();
@@ -81,16 +71,16 @@ abstract class AddConfig_Base
 	
 	public static function render()
 	{
-		if (self::$instance === false)
+		if (self::$instance === null)
 			ErrorHandler::traceError('No step instance yet');
-		if (self::$instance->edit !== false)
+		if (self::$instance->edit !== null)
 			Message::addInfo('replacing-config', self::$instance->edit->title());
 		self::$instance->renderInternal();
 	}
 	
 	public static function ajax()
 	{
-		if (self::$instance === false) {
+		if (self::$instance === null) {
 			ErrorHandler::traceError('No step instance yet');
 		}
 		self::$instance->ajaxInternal();
@@ -110,7 +100,7 @@ class AddConfig_Start extends AddConfig_Base
 		$mods = ConfigModule::getList();
 		$res = Database::simpleQuery("SELECT moduleid, title, moduletype, filepath FROM configtgz_module"
 			. " ORDER BY title ASC"); // Move to ConfigModule
-		if ($this->edit === false) {
+		if ($this->edit === null) {
 			$active = array();
 		} else {
 			$active = $this->edit->getModuleIds();
@@ -140,7 +130,7 @@ class AddConfig_Start extends AddConfig_Base
 			$row['active'] = in_array($row['moduleid'], $active);
 			$group['modules'][] = $row;
 		}
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			$title = $this->edit->title();
 		} else {
 			$title = Request::any('title', '', 'string');
@@ -162,7 +152,7 @@ class AddConfig_Start extends AddConfig_Base
 			'step' => 'AddConfig_Finish',
 			'groups' => array_values($modGroups),
 			'title' => $title,
-			'edit' => ($this->edit !== false ? $this->edit->id() : false)
+			'edit' => $this->edit === null ? null : $this->edit->id(),
 		));
 	}
 
@@ -174,9 +164,9 @@ class AddConfig_Start extends AddConfig_Base
 class AddConfig_Finish extends AddConfig_Base
 {
 	/**
-	 * @var ConfigTgz
+	 * @var ?ConfigTgz
 	 */
-	private $config = false;
+	private $config = null;
 	
 	protected function preprocessInternal()
 	{
@@ -186,13 +176,13 @@ class AddConfig_Finish extends AddConfig_Base
 			Message::addError('missing-file');
 			Util::redirect('?do=SysConfig&action=addconfig');
 		}
-		if ($this->edit === false) {
+		if ($this->edit === null) {
 			$this->config = ConfigTgz::insert($title, $modules);
 		} else {
 			$this->edit->update($title, $modules);
 			$this->config = $this->edit;
 		}
-		if ($this->config === false || $this->config->generate(true, 150) === false) {
+		if ($this->config->generate(true, 150) === false) {
 			Message::addError('unsuccessful-action');
 			Util::redirect('?do=SysConfig&action=addconfig');
 		}
diff --git a/modules-available/sysconfig/addmodule.inc.php b/modules-available/sysconfig/addmodule.inc.php
index c887f432..4564537e 100644
--- a/modules-available/sysconfig/addmodule.inc.php
+++ b/modules-available/sysconfig/addmodule.inc.php
@@ -9,31 +9,36 @@ abstract class AddModule_Base
 
 	/**
 	 * Holds the instance for the currently executing step
-	 * @var \AddModule_Base
+	 *
+	 * @var AddModule_Base
 	 */
 	private static $instance = false;
 	
 	/**
 	 * Instance of ConfigModule we're editing. False if not editing but creating.
-	 * @var \ConfigModule
+	 *
+	 * @var ?ConfigModule
 	 */
-	protected $edit = false;
+	protected $edit = null;
 
 	/**
 	 * 
 	 * @param string $step name of class representing the current step
 	 * @param int $editId (optional) overwrite for the request parameter 'edit'
 	 */
-	public static function setStep($step, $editId = false)
+	public static function setStep(string $step, int $editId = null): void
 	{
 		if (empty($step) || !class_exists($step) || get_parent_class($step) !== 'AddModule_Base') {
 			Message::addError('invalid-action', $step);
 			Util::redirect('?do=SysConfig');
 		}
 		self::$instance = new $step();
-		if ($editId = $editId ?: Request::any('edit')) {
+		if ($editId === null) {
+			$editId = Request::any('edit', 0, 'int');
+		}
+		if ($editId !== 0) {
 			self::$instance->edit = ConfigModule::get($editId);
-			if (self::$instance->edit === false)
+			if (self::$instance->edit === null)
 				ErrorHandler::traceError('Invalid module id for editing');
 			if ($step !== 'AddModule_Assign' && !preg_match('/^' . self::$instance->edit->moduleType() . '_/', $step))
 				ErrorHandler::traceError('Module to edit is of different type!');
@@ -100,7 +105,7 @@ abstract class AddModule_Base
 		if (self::$instance === false) {
 			ErrorHandler::traceError('No step instance yet');
 		}
-		if (get_class(self::$instance) !== 'AddModule_Assign' && self::$instance->edit !== false) {
+		if (get_class(self::$instance) !== 'AddModule_Assign' && self::$instance->edit !== null) {
 			Message::addInfo('replacing-module', self::$instance->edit->title());
 		}
 		self::$instance->renderInternal();
@@ -155,7 +160,7 @@ class AddModule_Assign extends AddModule_Base
 
 			if (ConfigModule::getList()[$moduleType]['unique']) {
 				$moduleIds = [];
-				foreach (ConfigModule::getAll($moduleType) as $module) {
+				foreach (ConfigModule::getAll($moduleType) ?? [] as $module) {
 					$moduleIds[] = $module->id();
 				}
 
@@ -209,41 +214,26 @@ class AddModule_Assign extends AddModule_Base
  * Helper functions to set/get a batch of vars from/to post variables or a module
  */
 
-/**
- * 
- * @param \ConfigModule $module
- * @param array $array
- * @param array $keys
- */
-function moduleToArray($module, &$array, $keys)
+function moduleToArray(ConfigModule $module, array &$array, array $keys): void
 {
 	foreach ($keys as $key) {
 		$array[$key] = $module->getData($key);
 	}
 }
 
-/**
- * 
- * @param \ConfigModule $module
- * @param array $array
- * @param array $keys
- */
-function arrayToModule($module, $array, $keys)
+function arrayToModule(ConfigModule $module, array $array, array $keys): void
 {
 	foreach ($keys as $key) {
 		$module->setData($key, $array[$key]);
 	}
 }
-/**
- * 
- * @param array $array
- * @param array $keys
- */
-function postToArray(&$array, $keys, $ignoreMissing = false)
+
+function postToArray(array &$array, array $keys, $ignoreMissing = false): void
 {
 	foreach ($keys as $key) {
 		$val = Request::post($key, '--not-in-post');
-		if ($ignoreMissing && $val === '--not-in-post') continue;
+		if ($ignoreMissing && $val === '--not-in-post')
+			continue;
 		$array[$key] = $val;
 	}
 }
diff --git a/modules-available/sysconfig/addmodule_adauth.inc.php b/modules-available/sysconfig/addmodule_adauth.inc.php
index b7e1cca0..2a695ab0 100644
--- a/modules-available/sysconfig/addmodule_adauth.inc.php
+++ b/modules-available/sysconfig/addmodule_adauth.inc.php
@@ -15,7 +15,7 @@ class AdAuth_Start extends AddModule_Base
 	{
 		$ADAUTH_COMMON_FIELDS = array('title', 'server', 'searchbase', 'binddn', 'bindpw', 'home', 'homeattr', 'ssl', 'genuid', 'certificate', 'mapping', 'nohomewarn');
 		$data = array();
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			moduleToArray($this->edit, $data, $ADAUTH_COMMON_FIELDS);
 			$data['title'] = $this->edit->title();
 			$data['edit'] = $this->edit->id();
@@ -35,7 +35,7 @@ class AdAuth_Start extends AddModule_Base
 		}
 		$data['step'] = 'AdAuth_CheckConnection';
 		$data['map_empty'] = true;
-		$data['mapping'] = ConfigModuleBaseLdap::getMapping(isset($data['mapping']) ? $data['mapping'] : false, $data['map_empty']);
+		$data['mapping'] = ConfigModuleBaseLdap::getMapping($data['mapping'] ?? null, $data['map_empty']);
 		Render::addDialog(Dictionary::translateFile('config-module', 'adAuth_title'), false, 'ad-start', $data);
 	}
 
@@ -94,7 +94,7 @@ class AdAuth_CheckConnection extends AddModule_Base
 
 	protected function renderInternal()
 	{
-		$mapping = Request::post('mapping', false, 'array');
+		$mapping = Request::post('mapping', null, 'array');
 		$data = array(
 			'edit' => Request::post('edit'),
 			'title' => Request::post('title'),
@@ -194,7 +194,7 @@ class AdAuth_SelfSearch extends AddModule_Base
 
 	protected function renderInternal()
 	{
-		$mapping = Request::post('mapping', false, 'array');
+		$mapping = Request::post('mapping', null, 'array');
 		$data = array(
 			'edit' => Request::post('edit'),
 			'title' => Request::post('title'),
@@ -287,7 +287,7 @@ class AdAuth_HomeAttrCheck extends AddModule_Base
 				'certificate' => Request::post('certificate', ''),
 				'originalbinddn' => Request::post('originalbinddn'),
 				'tryHomeAttr' => true,
-				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 				'prev' => 'AdAuth_Start',
 				'next' => 'AdAuth_CheckCredentials'
 			))
@@ -358,7 +358,7 @@ class AdAuth_CheckCredentials extends AddModule_Base
 				'fingerprint' => Request::post('fingerprint'),
 				'certificate' => Request::post('certificate', ''),
 				'originalbinddn' => Request::post('originalbinddn'),
-				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 				'prev' => 'AdAuth_Start',
 				'next' => 'AdAuth_HomeDir'
 			))
@@ -422,11 +422,11 @@ class AdAuth_HomeDir extends AddModule_Base
 			'fingerprint' => Request::post('fingerprint'),
 			'certificate' => Request::post('certificate', ''),
 			'originalbinddn' => Request::post('originalbinddn'),
-			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 			'prev' => 'AdAuth_Start',
 			'next' => 'AdAuth_Finish'
 		);
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			foreach (self::getAttributes() as $key) {
 				if ($this->edit->getData($key)) {
 					$data[$key . '_c'] = 'checked="checked"';
@@ -453,7 +453,7 @@ class AdAuth_HomeDir extends AddModule_Base
 		Render::addDialog(Dictionary::translateFile('config-module', 'adAuth_title'), false, 'ad_ldap-homedir', $data);
 	}
 
-	public static function getAttributes()
+	public static function getAttributes(): array
 	{
 		return array('shareRemapMode', 'shareRemapCreate', 'shareDocuments', 'shareDownloads', 'shareDesktop',
 			'shareMedia', 'shareOther', 'shareHomeDrive', 'shareDomain', 'credentialPassthrough');
@@ -471,10 +471,11 @@ class AdAuth_Finish extends AddModule_Base
 		$title = Request::post('title');
 		if (empty($title))
 			$title = 'AD: ' . Request::post('server');
-		if ($this->edit === false)
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('AdAuth');
-		else
+		} else {
 			$module = $this->edit;
+		}
 		$ssl = Request::post('ssl', 'off') === 'on';
 		foreach (['searchbase', 'binddn', 'server', 'bindpw', 'home', 'nohomewarn', 'homeattr', 'certificate', 'genuid',
 					'ldapAttrMountOpts', 'shareHomeMountOpts'] as $key) {
@@ -498,7 +499,7 @@ class AdAuth_Finish extends AddModule_Base
 		} else {
 			$module->setData('fingerprint', '');
 		}
-		if ($this->edit !== false)
+		if ($this->edit !== null)
 			$ret = $module->update($title);
 		else
 			$ret = $module->insert($title);
@@ -506,7 +507,7 @@ class AdAuth_Finish extends AddModule_Base
 			Message::addError('main.value-invalid', 'any', 'any');
 			$tgz = false;
 		} else {
-			$tgz = $module->generate($this->edit === false);
+			$tgz = $module->generate($this->edit === null);
 		}
 		if ($tgz === false) {
 			AddModule_Base::setStep('AdAuth_Start'); // Continues with AdAuth_Start for render()
@@ -516,7 +517,7 @@ class AdAuth_Finish extends AddModule_Base
 			'tm-config' => $tgz,
 		);
 
-		if ($this->edit === false) {
+		if ($this->edit === null) {
 			AddModule_Base::setStep('AddModule_Assign', $module->id());
 		}
 
diff --git a/modules-available/sysconfig/addmodule_branding.inc.php b/modules-available/sysconfig/addmodule_branding.inc.php
index f3a90e58..5d94a489 100644
--- a/modules-available/sysconfig/addmodule_branding.inc.php
+++ b/modules-available/sysconfig/addmodule_branding.inc.php
@@ -11,7 +11,7 @@ class Branding_Start extends AddModule_Base
 	{
 		Render::addDialog(Dictionary::translateFile('config-module', 'branding_title'), false, 'branding-start', array(
 			'step' => 'Branding_ProcessFile',
-			'edit' => $this->edit ? $this->edit->id() : false
+			'edit' => $this->edit == null ? null : $this->edit->id(),
 		));
 	}
 
@@ -47,7 +47,7 @@ class Branding_ProcessFile extends AddModule_Base
 			if (strpos($url, '://') === false)
 				$url = "http://$url";
 			$title = false;
-			if (!$this->downloadSvg($this->svgFile, $url, $title))
+			if (!Branding_ProcessFile::downloadSvg($this->svgFile, $url, $title))
 				Util::redirect('?do=SysConfig&action=addmodule&step=Branding_Start');
 			Session::set('logo_name', $title);
 		}
@@ -73,13 +73,13 @@ class Branding_ProcessFile extends AddModule_Base
 			$png = base64_encode(file_get_contents($this->task['data']['pngFile']));
 		if (filesize($this->svgFile) < 1000000)
 			$svg = base64_encode(file_get_contents($this->svgFile));
-		Render::addDialog(Dictionary::translate('config-module', 'branding_title'), false, 'branding-check', array(
+		Render::addDialog(Dictionary::translateFile('config-module', 'branding_title'), false, 'branding-check', array(
 			'png' => $png,
 			'svg' => $svg,
 			'error' => $this->task['data']['error'],
 			'step' => 'Branding_Finish',
-			'edit' => $this->edit ? $this->edit->id() : false,
-			'title' => $this->edit ? $this->edit->title() : false
+			'edit' => $this->edit === null ? null : $this->edit->id(),
+			'title' => $this->edit === null ? null : $this->edit->title(),
 			)
 		);
 		@unlink($this->svgFile);
@@ -94,7 +94,7 @@ class Branding_ProcessFile extends AddModule_Base
 	 * @return boolean true of download succeeded, false on download error (also returns true if downloaded file doesn't
 	 * 		seem to be svg!)
 	 */
-	private function downloadSvg($svgName, $url, &$title)
+	private static function downloadSvg(string $svgName, string $url, &$title): bool
 	{
 		$title = false;
 		// [wikipedia] Did someone paste a link to a thumbnail of the svg? Let's fix that...
@@ -121,7 +121,7 @@ class Branding_ProcessFile extends AddModule_Base
 				foreach ($out[1] as $res) {
 					if (strpos($res, 'action=edit') !== false)
 						continue;
-					$new = $this->internetCombineUrl($url, html_entity_decode($res, ENT_COMPAT, 'UTF-8'));
+					$new = Branding_ProcessFile::internetCombineUrl($url, html_entity_decode($res, ENT_COMPAT, 'UTF-8'));
 					if ($new !== $url)
 						break;
 				}
@@ -143,7 +143,7 @@ class Branding_ProcessFile extends AddModule_Base
 	 * @param string $relative relative url that will be converted to an absolute url
 	 * @return string combined absolute url
 	 */
-	private function internetCombineUrl($absolute, $relative)
+	private static function internetCombineUrl(string $absolute, string $relative): string
 	{
 		$p = parse_url($relative);
 		if (!empty($p["scheme"]))
@@ -206,29 +206,26 @@ class Branding_Finish extends AddModule_Base
 			Message::addError('main.error-read', $tgz);
 			Util::redirect('?do=SysConfig&action=addmodule&step=Branding_Start');
 		}
-		if ($this->edit === false)
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('Branding');
-		else
+		} else {
 			$module = $this->edit;
-		if ($module === false) {
-			Message::addError('main.error-read', 'branding.inc.php');
-			Util::redirect('?do=SysConfig&action=addmodule&step=Branding_Start');
 		}
 		$module->setData('tmpFile', $tgz);
-		if ($this->edit !== false)
+		if ($this->edit !== null)
 			$ret = $module->update($title);
 		else
 			$ret = $module->insert($title);
 		if (!$ret)
 			Util::redirect('?do=SysConfig&action=addmodule&step=Branding_Start');
-		elseif ($module->generate($this->edit === false, NULL, 200) === false)
+		elseif ($module->generate($this->edit === null, NULL, 200) === false)
 			Util::redirect('?do=SysConfig&action=addmodule&step=Branding_Start');
 		Session::set('logo_tgz', false);
 		Session::set('logo_name', false);
 		// Yay
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			Message::addSuccess('module-edited');
-		else {
+		} else {
 			Message::addSuccess('module-added');
 			AddModule_Base::setStep('AddModule_Assign', $module->id());
 			return;
diff --git a/modules-available/sysconfig/addmodule_custommodule.inc.php b/modules-available/sysconfig/addmodule_custommodule.inc.php
index 234aed0d..3afdad0a 100644
--- a/modules-available/sysconfig/addmodule_custommodule.inc.php
+++ b/modules-available/sysconfig/addmodule_custommodule.inc.php
@@ -14,7 +14,7 @@ class CustomModule_Start extends AddModule_Base
 		Session::set('mod_temp', false);
 		Render::addDialog(Dictionary::translateFile('config-module', 'custom_title'), false, 'custom-upload', array(
 			'step' => 'CustomModule_ProcessUpload',
-			'edit' => $this->edit ? $this->edit->id() : false
+			'edit' => $this->edit === null ? null : $this->edit->id(),
 			));
 	}
 
@@ -69,17 +69,17 @@ class CustomModule_ProcessUpload extends AddModule_Base
 		}
 		$list = SysConfig::archiveContentsFromTask($status, $userGroupWarn);
 
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			$title = $this->edit->title();
 		} else if (isset($_FILES['modulefile']['name'])) {
 			$title = basename($_FILES['modulefile']['name']);
 		} else {
 			$title = '';
 		}
-		Render::addDialog(Dictionary::translate('config-module', 'custom_title'), false, 'custom-fileselect', array(
+		Render::addDialog(Dictionary::translateFile('config-module', 'custom_title'), false, 'custom-fileselect', array(
 			'step' => 'CustomModule_CompressModule',
 			'files' => $list,
-			'edit' => $this->edit ? $this->edit->id() : false,
+			'edit' => $this->edit === null ? null : $this->edit->id(),
 			'title' => $title,
 			'userGroupWarn' => $userGroupWarn,
 		));
@@ -116,28 +116,26 @@ class CustomModule_CompressModule extends AddModule_Base
 			$this->taskError($status);
 		}
 		// Seems ok, create entry
-		if ($this->edit === false)
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('CustomModule');
-		else
+		} else {
 			$module = $this->edit;
-		if ($module === false) {
-			Message::addError('main.error-read', 'custommodule.inc.php');
-			Util::redirect('?do=SysConfig&action=addmodule&step=CustomModule_Start');
 		}
 		$module->setData('tmpFile', $destFile);
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			$ret = $module->update($title);
-		else
+		} else {
 			$ret = $module->insert($title);
+		}
 		if (!$ret)
 			Util::redirect('?do=SysConfig&action=addmodule&step=CustomModule_Start');
-		elseif (!$module->generate($this->edit === false, NULL, 200))
+		elseif (!$module->generate($this->edit === null, NULL, 200))
 			Util::redirect('?do=SysConfig&action=addmodule&step=CustomModule_Start');
 		Session::set('mod_temp', false);
 		// Yay
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			Message::addSuccess('module-edited');
-		else {
+		} else {
 			Message::addSuccess('module-added');
 			AddModule_Base::setStep('AddModule_Assign', $module->id());
 			return;
diff --git a/modules-available/sysconfig/addmodule_ldapauth.inc.php b/modules-available/sysconfig/addmodule_ldapauth.inc.php
index fe5ff706..6a385d9c 100644
--- a/modules-available/sysconfig/addmodule_ldapauth.inc.php
+++ b/modules-available/sysconfig/addmodule_ldapauth.inc.php
@@ -11,7 +11,7 @@ class LdapAuth_Start extends AddModule_Base
 	{
 		$LDAPAUTH_COMMON_FIELDS = array('title', 'server', 'searchbase', 'binddn', 'bindpw', 'home', 'homeattr', 'ssl', 'genuid', 'certificate', 'mapping', 'nohomewarn');
 		$data = array();
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			moduleToArray($this->edit, $data, $LDAPAUTH_COMMON_FIELDS);
 			$data['title'] = $this->edit->title();
 			$data['edit'] = $this->edit->id();
@@ -27,7 +27,7 @@ class LdapAuth_Start extends AddModule_Base
 		}
 		$data['step'] = 'LdapAuth_CheckConnection';
 		$data['map_empty'] = true;
-		$data['mapping'] = ConfigModuleBaseLdap::getMapping(isset($data['mapping']) ? $data['mapping'] : false, $data['map_empty']);
+		$data['mapping'] = ConfigModuleBaseLdap::getMapping($data['mapping'] ?? null, $data['map_empty']);
 		Render::addDialog(Dictionary::translateFile('config-module', 'ldapAuth_title'), false, 'ldap-start', $data);
 	}
 
@@ -81,7 +81,7 @@ class LdapAuth_CheckConnection extends AddModule_Base
 			'genuid' => Request::post('genuid'),
 			'certificate' => Request::post('certificate', ''),
 			'taskid' => $this->scanTask['id'],
-			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 		);
 		$data['prev'] = 'LdapAuth_Start';
 		$data['next'] = 'LdapAuth_CheckCredentials';
@@ -152,7 +152,7 @@ class LdapAuth_CheckCredentials extends AddModule_Base
 				'genuid' => Request::post('genuid'),
 				'fingerprint' => Request::post('fingerprint'),
 				'certificate' => Request::post('certificate', ''),
-				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+				'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 				'prev' => 'LdapAuth_Start',
 				'next' => 'LdapAuth_HomeDir',
 			))
@@ -193,11 +193,11 @@ class LdapAuth_HomeDir extends AddModule_Base
 			'fingerprint' => Request::post('fingerprint'),
 			'certificate' => Request::post('certificate', ''),
 			'originalbinddn' => Request::post('originalbinddn'),
-			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', false, 'array')),
+			'mapping' => ConfigModuleBaseLdap::getMapping(Request::post('mapping', null, 'array')),
 			'prev' => 'LdapAuth_Start',
 			'next' => 'LdapAuth_Finish',
 		);
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			foreach (self::getAttributes() as $key) {
 				if ($this->edit->getData($key)) {
 					$data[$key . '_c'] = 'checked="checked"';
@@ -224,7 +224,7 @@ class LdapAuth_HomeDir extends AddModule_Base
 		Render::addDialog(Dictionary::translateFile('config-module', 'ldapAuth_title'), false, 'ad_ldap-homedir', $data);
 	}
 
-	public static function getAttributes()
+	public static function getAttributes(): array
 	{
 		return array('shareRemapMode', 'shareRemapCreate', 'shareDocuments', 'shareDownloads', 'shareDesktop',
 			'shareMedia', 'shareOther', 'shareHomeDrive', 'shareDomain', 'credentialPassthrough');
@@ -242,10 +242,11 @@ class LdapAuth_Finish extends AddModule_Base
 		$title = Request::post('title');
 		if (empty($title))
 			$title = 'LDAP: ' . Request::post('server');
-		if ($this->edit === false)
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('LdapAuth');
-		else
+		} else {
 			$module = $this->edit;
+		}
 		$ssl = Request::post('ssl', 'off') === 'on';
 		foreach (['searchbase', 'binddn', 'server', 'bindpw', 'home', 'nohomewarn', 'certificate', 'genuid',
 						'ldapAttrMountOpts', 'shareHomeMountOpts'] as $key) {
@@ -269,15 +270,16 @@ class LdapAuth_Finish extends AddModule_Base
 		} else {
 			$module->setData('fingerprint', '');
 		}
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			$ret = $module->update($title);
-		else
+		} else {
 			$ret = $module->insert($title);
+		}
 		if (!$ret) {
 			Message::addError('main.value-invalid', 'any', 'any');
 			$tgz = false;
 		} else {
-			$tgz = $module->generate($this->edit === false);
+			$tgz = $module->generate($this->edit === null);
 		}
 		if ($tgz === false) {
 			AddModule_Base::setStep('LdapAuth_Start'); // Continues with LdapAuth_Start for render()
@@ -287,7 +289,7 @@ class LdapAuth_Finish extends AddModule_Base
 			'tm-config' => $tgz,
 		);
 
-		if ($this->edit === false) {
+		if ($this->edit === null) {
 			AddModule_Base::setStep('AddModule_Assign', $module->id());
 		}
 	}
diff --git a/modules-available/sysconfig/addmodule_screensaver.inc.php b/modules-available/sysconfig/addmodule_screensaver.inc.php
index 24dfadd0..7b6d0afb 100644
--- a/modules-available/sysconfig/addmodule_screensaver.inc.php
+++ b/modules-available/sysconfig/addmodule_screensaver.inc.php
@@ -14,7 +14,7 @@ class Screensaver_Start extends AddModule_Base
 		if (Request::get('back', 'false', 'string') !== 'false')
 			/* If coming via the back button, load the session data */
 			$this->session_data = Session::get('data');
-		elseif ($this->edit !== false) {
+		elseif ($this->edit !== null) {
 			$this->session_data = array(
 				'title' => $this->edit->title(),
 				'qss' => $this->edit->getData('qss'),
@@ -24,22 +24,22 @@ class Screensaver_Start extends AddModule_Base
 		} else {
 			$this->session_data = array(
 				'title' => '',
-				'qss' => Dictionary::translate('saver_QssDefault', true),
+				'qss' => Dictionary::translate('saver_QssDefault'),
 				'messages' => array(
 					'General' => array(
-						'shutdown' => Dictionary::translate('saver_MessageDefaultShutdown', true),
-						'shutdown-locked' => Dictionary::translate('saver_MessageDefaultShutdownLocked', true),
-						'idle-kill' => Dictionary::translate('saver_MessageDefaultIdleKill', true),
-						'idle-kill-locked' => Dictionary::translate('saver_MessageDefaultIdleKillLocked', true),
-						'no-timeout' => Dictionary::translate('saver_MessageDefaultNoTimeout', true),
-						'no-timeout-locked' => Dictionary::translate('saver_MessageDefaultNoTimeoutLocked', true),
+						'shutdown' => Dictionary::translate('saver_MessageDefaultShutdown'),
+						'shutdown-locked' => Dictionary::translate('saver_MessageDefaultShutdownLocked'),
+						'idle-kill' => Dictionary::translate('saver_MessageDefaultIdleKill'),
+						'idle-kill-locked' => Dictionary::translate('saver_MessageDefaultIdleKillLocked'),
+						'no-timeout' => Dictionary::translate('saver_MessageDefaultNoTimeout'),
+						'no-timeout-locked' => Dictionary::translate('saver_MessageDefaultNoTimeoutLocked'),
 					)
 				),
 				'texts' => array(
-					'text-shutdown' => Dictionary::translate('saver_TextDefaultShutdown', true),
+					'text-shutdown' => Dictionary::translate('saver_TextDefaultShutdown'),
 					'text-shutdown-locked' => '',
-					'text-idle-kill' => Dictionary::translate('saver_TextDefaultIdleKill', true),
-					'text-idle-kill-locked' => Dictionary::translate('saver_TextDefaultIdleKillLocked', true),
+					'text-idle-kill' => Dictionary::translate('saver_TextDefaultIdleKill'),
+					'text-idle-kill-locked' => Dictionary::translate('saver_TextDefaultIdleKillLocked'),
 					'text-no-timeout' => '',
 					'text-no-timeout-locked' => '',
 				),
@@ -56,7 +56,7 @@ class Screensaver_Start extends AddModule_Base
 		Render::addDialog(Dictionary::translateFile('config-module', 'screensaver_title'), false, 'screensaver-start', array(
 			'step' => 'Screensaver_Text',
 			'next' => 'idle-kill',
-			'edit' => $this->edit ? $this->edit->id() : 0,
+			'edit' => $this->edit !== null ? $this->edit->id() : 0,
 			'id' => 'start',
 			'title' => $this->session_data['title'],
 			'qss' => $this->session_data['qss'],
@@ -98,7 +98,7 @@ class Screensaver_Text extends AddModule_Base
 		$next = $this->session_data['next'];
 
 		$data = array(
-			'edit' => $this->edit ? $this->edit->id() : 0,
+			'edit' => $this->edit !== null ? $this->edit->id() : 0,
 		);
 
 		/* Prepare and translate labels for the frontend */
@@ -114,8 +114,8 @@ class Screensaver_Text extends AddModule_Base
 		 * Dictionary::translate('saver_TitleShutdown');
 		 * Dictionary::translate('saver_DescriptionShutdown');
 		 */
-		$data['title'] = Dictionary::translate('saver_Title' . $tag, true);
-		$data['description'] = Dictionary::translate('saver_Description' . $tag, true);
+		$data['title'] = Dictionary::translate('saver_Title' . $tag);
+		$data['description'] = Dictionary::translate('saver_Description' . $tag);
 		$data['msg_value'] = $this->session_data['messages']['General'][$next];
 		$data['msg_locked_value'] = $this->session_data['messages']['General'][$next . '-locked'];
 		$data['text_value'] = $this->session_data['texts']['text-' . $next];
@@ -150,14 +150,14 @@ class Screensaver_Finish extends AddModule_Base
 		if (empty($session_data['title'])) {
 			Message::addError('missing-title');
 			Util::redirect('?do=SysConfig');
-			return;
 		}
 
 		/* Only create an instance, if it's a new one */
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			$module = $this->edit;
-		else
+		} else {
 			$module = ConfigModule::getInstance('Screensaver');
+		}
 
 		/* Set all the data to the module instance */
 		$module->setData('qss', $session_data['qss']);
@@ -165,15 +165,16 @@ class Screensaver_Finish extends AddModule_Base
 		$module->setData('texts', $session_data['texts']);
 
 		/* Insert or update database entries */
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			$module->update($session_data['title']);
-		else
+		} else {
 			$module->insert($session_data['title']);
+		}
 
-		$task = $module->generate($this->edit === false);
+		$task = $module->generate($this->edit === null);
 
 		// Yay
-		if ($task !== false && $this->edit !== false)
+		if ($task !== false && $this->edit !== null)
 			Message::addSuccess('module-edited');
 		elseif ($task !== false) {
 			Message::addSuccess('module-added');
@@ -192,7 +193,6 @@ class Screensaver_Helper
 		if (empty($session_data['title'])) {
 			Message::addError('missing-title');
 			Util::redirect('?do=SysConfig');
-			return;
 		}
 		$session_data['qss'] = Request::post('qss', $session_data['qss'], 'string');
 		$helperMode = Request::post('helper_mode', 'false', 'string');
diff --git a/modules-available/sysconfig/addmodule_sshconfig.inc.php b/modules-available/sysconfig/addmodule_sshconfig.inc.php
index 4a75d77e..2447f9be 100644
--- a/modules-available/sysconfig/addmodule_sshconfig.inc.php
+++ b/modules-available/sysconfig/addmodule_sshconfig.inc.php
@@ -9,8 +9,8 @@ class SshConfig_Start extends AddModule_Base
 
 	protected function renderInternal()
 	{
-		if ($this->edit !== false) {
-			$data = $this->edit->getData(false) + array(
+		if ($this->edit !== null) {
+			$data = $this->edit->getData(null) + array(
 				'title' => $this->edit->title(),
 				'edit' => $this->edit->id(),
 				'PWD_' . strtoupper($this->edit->getData('allowPasswordLogin')) . '_selected' => 'selected',
@@ -40,10 +40,11 @@ class SshConfig_Finish extends AddModule_Base
 			return;
 		}
 		// Seems ok, create entry
-		if ($this->edit === false)
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('SshConfig');
-		else
+		} else {
 			$module = $this->edit;
+		}
 		if ($module === false) {
 			Message::addError('main.error-read', 'sshconfig.inc.php');
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshConfig_Start');
@@ -59,18 +60,20 @@ class SshConfig_Finish extends AddModule_Base
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshConfig_Start');
 		}
 		$module->setData('publicKey', false);
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			$ret = $module->update($title);
-		else
+		} else {
 			$ret = $module->insert($title);
-		if (!$ret)
+		}
+		if (!$ret) {
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshConfig_Start');
-		elseif (!$module->generate($this->edit === false, NULL, 200))
+		} elseif (!$module->generate($this->edit === null, NULL, 200)) {
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshConfig_Start');
+		}
 		// Yay
-		if ($this->edit !== false)
+		if ($this->edit !== null) {
 			Message::addSuccess('module-edited');
-		else {
+		} else {
 			Message::addSuccess('module-added');
 			AddModule_Base::setStep('AddModule_Assign', $module->id());
 			return;
diff --git a/modules-available/sysconfig/addmodule_sshkey.inc.php b/modules-available/sysconfig/addmodule_sshkey.inc.php
index b5ab4ad6..9f5bd1d3 100644
--- a/modules-available/sysconfig/addmodule_sshkey.inc.php
+++ b/modules-available/sysconfig/addmodule_sshkey.inc.php
@@ -9,8 +9,8 @@ class SshKey_Start extends AddModule_Base
 
 	protected function renderInternal()
 	{
-		if ($this->edit !== false) {
-			$data = $this->edit->getData(false) + array(
+		if ($this->edit !== null) {
+			$data = $this->edit->getData(null) + array(
 					'title' => $this->edit->title(),
 					'edit' => $this->edit->id(),
 				);
@@ -35,7 +35,7 @@ class SshKey_Finish extends AddModule_Base
 			return;
 		}
 		// Seems ok, create entry
-		if ($this->edit === false) {
+		if ($this->edit === null) {
 			$module = ConfigModule::getInstance('SshKey');
 		} else {
 			$module = $this->edit;
@@ -48,18 +48,18 @@ class SshKey_Finish extends AddModule_Base
 			Message::addError('main.value-invalid', 'pubkey', Request::post('publicKey'));
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshKey_Start');
 		}
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			$ret = $module->update($title);
 		} else {
 			$ret = $module->insert($title);
 		}
 		if (!$ret) {
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshKey_Start');
-		} elseif (!$module->generate($this->edit === false, NULL, 200)) {
+		} elseif (!$module->generate($this->edit === null, NULL, 200)) {
 			Util::redirect('?do=SysConfig&action=addmodule&step=SshKey_Start');
 		}
 		// Yay
-		if ($this->edit !== false) {
+		if ($this->edit !== null) {
 			Message::addSuccess('module-edited');
 		} else {
 			Message::addSuccess('module-added');
diff --git a/modules-available/sysconfig/api.inc.php b/modules-available/sysconfig/api.inc.php
index c81d37b5..e7be3029 100644
--- a/modules-available/sysconfig/api.inc.php
+++ b/modules-available/sysconfig/api.inc.php
@@ -11,9 +11,9 @@ if (substr($ip, 0, 7) === '::ffff:') {
 	$ip = substr($ip, 7);
 }
 
-$uuid = Request::any('uuid', false, 'string');
-if ($uuid !== false && strlen($uuid) !== 36) {
-	$uuid = false;
+$uuid = Request::any('uuid', null, 'string');
+if ($uuid !== null && strlen($uuid) !== 36) {
+	$uuid = null;
 }
 
 // What we do if we can't supply the requested config
diff --git a/modules-available/sysconfig/inc/configmodule.inc.php b/modules-available/sysconfig/inc/configmodule.inc.php
index e414a6cf..729cb959 100644
--- a/modules-available/sysconfig/inc/configmodule.inc.php
+++ b/modules-available/sysconfig/inc/configmodule.inc.php
@@ -7,18 +7,23 @@ abstract class ConfigModule
 {
 
 	/**
-	 * @var array list of known module types
+	 * @var ?array{'title': string,
+	 * 'description': string,
+	 * 'group': string,
+	 * 'unique': bool,
+	 * 'sortOrder': int,
+	 * 'moduleClass': string,
+	 * 'wizardClass': string}[] list of known module types
 	 */
-	private static $moduleTypes = false;
+	private static $moduleTypes = null;
 
 	private $moduleId = 0;
-	private $moduleArchive = false;
-	private $moduleTitle = false;
-	private $moduleStatus = false;
-	/**
-	 * @var int
-	 */
+	private $moduleArchive = '';
+	private $moduleTitle = '';
+	private $moduleStatus = 'MISSING';
+	/** @var int */
 	private $dateline = 0;
+	/** @var int */
 	private $currentVersion = 0;
 	/**
 	 * @var false|array Data of module, false if not initialized
@@ -33,9 +38,9 @@ abstract class ConfigModule
 	 */
 	public static function loadDb()
 	{
-		if (self::$moduleTypes !== false)
+		if (self::$moduleTypes !== null)
 			return;
-		self::$moduleTypes = array();
+		self::$moduleTypes = [];
 		Module::isAvailable('sysconfig');
 		foreach (glob(dirname(__FILE__) . '/configmodule/*.inc.php', GLOB_NOSORT) as $file) {
 			require_once $file;
@@ -44,10 +49,16 @@ abstract class ConfigModule
 
 	/**
 	 * Get all known config module types.
-	 *
-	 * @return array list of modules
+	 * @return  array{'title': string,
+	 *  'description': string,
+	 *  'group': string,
+	 *  'unique': bool,
+	 *  'sortOrder': int,
+	 *  'moduleClass': string,
+	 *  'wizardClass': string}[] list of known module types
+	 * /
 	 */
-	public static function getList()
+	public static function getList(): array
 	{
 		self::loadDb();
 		return self::$moduleTypes;
@@ -63,9 +74,9 @@ abstract class ConfigModule
 	 * @param string $description Description for this module type
 	 * @param string $group Title for group this module type belongs to
 	 * @param bool $unique Can only one such module be added to a config?
-	 * @param int $sortOrder Lower comes first, alphabetical ordering otherwiese
+	 * @param int $sortOrder Lower comes first, alphabetical ordering otherwise
 	 */
-	public static function registerModule($id, $title, $description, $group, $unique, $sortOrder = 0)
+	public static function registerModule(string $id, string $title, string $description, string $group, bool $unique, int $sortOrder = 0): void
 	{
 		if (isset(self::$moduleTypes[$id])) {
 			ErrorHandler::traceError("Config Module $id already registered!");
@@ -93,21 +104,33 @@ abstract class ConfigModule
 	 * Get fresh instance of ConfigModule subclass for given module type.
 	 *
 	 * @param string $moduleType name of module type
-	 * @return false|\ConfigModule module instance
+	 * @return ConfigModule module instance
 	 */
-	public static function getInstance($moduleType)
+	public static function getInstance(string $moduleType): ConfigModule
+	{
+		$ret = self::getInstanceOrNull($moduleType);
+		if ($ret === null) {
+			Message::addError('main.error-read', $moduleType . '.inc.php');
+			Util::redirect('?do=sysconfig');
+		}
+		return $ret;
+	}
+
+	public static function getInstanceOrNull(string $moduleType): ?ConfigModule
 	{
 		self::loadDb();
 		if (!isset(self::$moduleTypes[$moduleType])) {
 			error_log('Unknown module type: ' . $moduleType);
-			return false;
+			return null;
 		}
 		return new self::$moduleTypes[$moduleType]['moduleClass'];
 	}
 
-	public static function instanceFromDbRow($dbRow)
+	private static function instanceFromDbRow(array $dbRow): ?ConfigModule
 	{
-		$instance = self::getInstance($dbRow['moduletype']);
+		$instance = self::getInstanceOrNull($dbRow['moduletype']);
+		if ($instance === null)
+			return null;
 		$instance->currentVersion = $dbRow['version'];
 		$instance->moduleArchive = $dbRow['filepath'];
 		$instance->moduleData = json_decode($dbRow['contents'], true);
@@ -125,37 +148,37 @@ abstract class ConfigModule
 	 * Get module instance from id.
 	 *
 	 * @param int $moduleId module id to get
-	 * @return false|\ConfigModule The requested module from DB, or false on error
+	 * @return ?ConfigModule The requested module from DB, or null on error
 	 */
-	public static function get($moduleId)
+	public static function get(int $moduleId): ?ConfigModule
 	{
 		$ret = Database::queryFirst("SELECT moduleid, title, moduletype, filepath, contents, version, status, dateline FROM configtgz_module "
 				. " WHERE moduleid = :moduleid LIMIT 1", array('moduleid' => $moduleId));
 		if ($ret === false)
-			return false;
+			return null;
 		return self::instanceFromDbRow($ret);
 	}
 
 	/**
 	 * Get module instances from module type.
 	 *
-	 * @param int $moduleType module type to get
-	 * @return \ConfigModule[]|false The requested modules from DB, or false on error
+	 * @param string $moduleType module type to get
+	 * @return ?ConfigModule[] The requested modules from DB, or null on error
 	 */
-	public static function getAll($moduleType = false)
+	public static function getAll(string $moduleType = null): ?array
 	{
-		if ($moduleType === false) {
+		if ($moduleType === null) {
 			$ret = Database::simpleQuery("SELECT moduleid, title, moduletype, filepath, contents, version, status, dateline FROM configtgz_module");
 		} else {
 			$ret = Database::simpleQuery("SELECT moduleid, title, moduletype, filepath, contents, version, status, dateline FROM configtgz_module "
 					. " WHERE moduletype = :moduletype", array('moduletype' => $moduleType));
 		}
 		if ($ret === false)
-			return false;
+			return null;
 		$list = array();
 		foreach ($ret as $row) {
 			$instance = self::instanceFromDbRow($row);
-			if ($instance === false)
+			if ($instance === null)
 				continue;
 			$list[] = $instance;
 		}
@@ -167,37 +190,37 @@ abstract class ConfigModule
 	 * 
 	 * @return int module version
 	 */
-	protected abstract function moduleVersion();
+	protected abstract function moduleVersion(): int;
 
 	/**
 	 * Validate the module's configuration.
 	 * 
-	 * @return boolean ok or not
+	 * @return bool ok or not
 	 */
-	protected abstract function validateConfig();
+	protected abstract function validateConfig(): bool;
 
 	/**
 	 * Set module specific data.
 	 * 
 	 * @param string $key key, name or id of data being set
 	 * @param mixed $value Module specific data
-	 * @return boolean true if data was successfully set, false otherwise (i.e. invalid data being set)
+	 * @return bool true if data was successfully set, false otherwise (i.e. invalid data being set)
 	 */
-	public abstract function setData($key, $value);
+	public abstract function setData(string $key, $value): bool;
 	
 	/**
 	 * Get module specific data.
 	 * Can be overridden by modules.
 	 * 
-	 * @param string $key key, name or id of data to get, or false to get the raw moduleData array
+	 * @param ?string $key key, name or id of data to get, or null to get the raw moduleData array
 	 * @return mixed Module specific data
 	 */
-	public function getData($key)
+	public function getData(?string $key)
 	{
-		if ($key === false)
+		if ($key === null)
 			return $this->moduleData;
 		if (!is_array($this->moduleData) || !isset($this->moduleData[$key]))
-			return false;
+			return null;
 		return $this->moduleData[$key];
 	}
 
@@ -205,25 +228,25 @@ abstract class ConfigModule
 	 * Module specific version of generate.
 	 * 
 	 * @param string $tgz File name of tgz module to write final output to
-	 * @param string $parent Parent task of this task
+	 * @param string|null $parent Parent task of this task
 	 * @return array|boolean true if generation is completed immediately,
 	 * 		a task struct if some task needs to be run for generation,
 	 * 		false on error
 	 */
-	protected abstract function generateInternal($tgz, $parent);
+	protected abstract function generateInternal(string $tgz, ?string $parent);
 
-	private function createFileName()
+	private function createFileName(): string
 	{
 		return CONFIG_TGZ_LIST_DIR . '/modules/'
 			. $this->moduleType() . '_id-' . $this->moduleId . '__' . mt_rand() . '-' . time() . '.tgz';
 	}
 
-	public function allowDownload()
+	public function allowDownload(): bool
 	{
 		return false;
 	}
 
-	public function needRebuild()
+	public function needRebuild(): bool
 	{
 		return $this->moduleStatus !== 'OK' || $this->currentVersion < $this->moduleVersion();
 	}
@@ -233,17 +256,15 @@ abstract class ConfigModule
 	 *
 	 * @return int id
 	 */
-	public final function id()
+	public final function id(): int
 	{
 		return $this->moduleId;
 	}
 	
 	/**
 	 * Get module title.
-	 *
-	 * @return string
 	 */
-	public final function title()
+	public final function title(): string
 	{
 		return $this->moduleTitle;
 	}
@@ -253,17 +274,17 @@ abstract class ConfigModule
 	 *
 	 * @return string tgz file absolute path
 	 */
-	public final function archive()
+	public final function archive(): string
 	{
 		return $this->moduleArchive;
 	}
 
-	public final function status()
+	public final function status(): string
 	{
 		return $this->moduleStatus;
 	}
 
-	public final function currentVersion()
+	public final function currentVersion(): int
 	{
 		return $this->currentVersion;
 	}
@@ -273,11 +294,10 @@ abstract class ConfigModule
 	 *
 	 * @return string module type
 	 */
-	public final function moduleType()
+	public final function moduleType(): string
 	{
+		// Yes, need to pass $this, otherwise we get ConfigModule, the base class this function is part of
 		$name = get_class($this);
-		if ($name === false)
-			ErrorHandler::traceError('ConfigModule::moduleType: get_class($this) returned false!');
 		// ConfigModule_*
 		if (!preg_match('/^ConfigModule_(\w+)$/', $name, $out))
 			ErrorHandler::traceError('ConfigModule::moduleType: get_class($this) returned "' . $name . '"');
@@ -292,7 +312,7 @@ abstract class ConfigModule
 	 * @param string $title display name of the module
 	 * @return boolean true if inserted successfully, false if module config is invalid
 	 */
-	public final function insert($title)
+	public final function insert(string $title): bool
 	{
 		if ($this->moduleId !== 0)
 			ErrorHandler::traceError('ConfigModule::insert called when moduleId != 0');
@@ -326,7 +346,7 @@ abstract class ConfigModule
 	 *
 	 * @return boolean true on success, false otherwise
 	 */
-	public final function update($title = '')
+	public final function update(string $title = ''): bool
 	{
 		if ($this->moduleId === 0)
 			ErrorHandler::traceError('ConfigModule::update called when moduleId == 0');
@@ -353,15 +373,15 @@ abstract class ConfigModule
 	 * Updating the database etc. will happen later through a callback.
 	 *
 	 * @param boolean $deleteOnError if true, the db entry will be deleted if generation failed
-	 * @param string $parent Parent task of this task
+	 * @param string|null $parent Parent task of this task
 	 * @param int $timeoutMs maximum time in milliseconds we wait for completion
 	 * @return string|boolean task id if deferred generation was started,
 	 * 		true if generation succeeded (without using a task or within $timeoutMs)
 	 * 		false on error
 	 */
-	public final function generate($deleteOnError, $parent = NULL, $timeoutMs = 0)
+	public final function generate(bool $deleteOnError, string $parent = NULL, int $timeoutMs = 0)
 	{
-		if ($this->moduleId === 0 || $this->moduleTitle === false)
+		if ($this->moduleId === 0 || empty($this->moduleTitle))
 			ErrorHandler::traceError('ConfigModule::generateAsync called on uninitialized/uninserted module!');
 		$tmpTgz = '/tmp/bwlp-id-' . $this->moduleId . '_' . mt_rand() . '_' . time() . '.tgz';
 		$ret = $this->generateInternal($tmpTgz, $parent);
@@ -395,7 +415,7 @@ abstract class ConfigModule
 	/**
 	 * Delete the module.
 	 */
-	public final function delete()
+	public final function delete(): void
 	{
 		if ($this->moduleId === 0)
 			ErrorHandler::traceError('ConfigModule::delete called with invalid module id!');
@@ -410,17 +430,19 @@ abstract class ConfigModule
 			$this->moduleTitle = false;
 			$this->moduleArchive = false;
 		}
-		return $ret;
 	}
 
-	private function markUpdated($tmpTgz)
+	/**
+	 * @param ?string $tmpTgz new tar archive to use for this module, or null if the old one is still valid
+	 */
+	private function markUpdated(?string $tmpTgz): bool
 	{
 		if ($this->moduleId === 0)
 			ErrorHandler::traceError('ConfigModule::markUpdated called with invalid module id!');
-		if ($this->moduleArchive === false)
+		if ($this->moduleArchive === null)
 			$this->moduleArchive = $this->createFileName();
 		// Move file
-		if ($tmpTgz === false) {
+		if ($tmpTgz === null) {
 			if (!file_exists($this->moduleArchive)) {
 				EventLog::failure('ConfigModule::markUpdated for "' . $this->moduleTitle . '" called with no tmpTgz and no existing tgz!');
 				$this->markFailed();
@@ -460,16 +482,18 @@ abstract class ConfigModule
 		return $retval;
 	}
 
-	private function markFailed()
+	private function markFailed(): void
 	{
 		if ($this->moduleId === 0)
 			ErrorHandler::traceError('ConfigModule::markFailed called with invalid module id!');
-		if ($this->moduleArchive === false)
+		if ($this->moduleArchive === '') {
 			$this->moduleArchive = $this->createFileName();
-		if (!file_exists($this->moduleArchive))
+		}
+		if (!file_exists($this->moduleArchive)) {
 			$status = 'MISSING';
-		else
+		} else {
 			$status = 'OUTDATED';
+		}
 		Database::exec("UPDATE configtgz_module SET filepath = :filename, status = :status WHERE moduleid = :id LIMIT 1", array(
 				'id' => $this->moduleId,
 				'filename' => $this->moduleArchive,
@@ -477,7 +501,7 @@ abstract class ConfigModule
 			));
 	}
 
-	public function dateline_s()
+	public function dateline_s(): string
 	{
 		return Util::prettyTime($this->dateline);
 	}
@@ -489,7 +513,7 @@ abstract class ConfigModule
 	 * Override this if you need to handle this, otherwise
 	 * the base implementation does nothing.
 	 */
-	public function event_serverIpChanged()
+	public function event_serverIpChanged(): void
 	{
 		// Do::Nothing()
 	}
@@ -500,11 +524,10 @@ abstract class ConfigModule
 	 * Will be called if the server's IP address changes. The event will be propagated
 	 * to all config module classes so action can be taken if appropriate.
 	 */
-	public static function serverIpChanged()
+	public static function serverIpChanged(): void
 	{
 		self::loadDb();
-		$list = self::getAll();
-		foreach ($list as $mod) {
+		foreach (self::getAll() ?? [] as $mod) {
 			$mod->event_serverIpChanged();
 		}
 	}
@@ -513,53 +536,51 @@ abstract class ConfigModule
 	 * Called when (re)generating a config module failed, so we can
 	 * update the status in the DB and add a server log entry.
 	 *
-	 * @param array $task
-	 * @param array $args contains 'moduleid' and optionally 'deleteOnError' and 'tmpTgz'
+	 * @param array $args contains 'moduleid' and optionally 'deleteOnError'
 	 */
-	public static function generateFailed($task, $args)
+	public static function generateFailed(array $task, array $args): void
 	{
 		if (!isset($args['moduleid']) || !is_numeric($args['moduleid'])) {
 			EventLog::warning('Ignoring generateFailed event as it has no moduleid assigned.');
 			return;
 		}
 		$module = self::get($args['moduleid']);
-		if ($module === false) {
+		if ($module === null) {
 			EventLog::warning('generateFailed callback for module id ' . $args['moduleid'] . ', but no instance could be generated.');
 			return;
 		}
-		if (isset($task['data']['error']))
+		if (isset($task['data']['error'])) {
 			$error = $task['data']['error'];
-		elseif (isset($task['data']['messages']))
+		} elseif (isset($task['data']['messages'])) {
 			$error = $task['data']['messages'];
-		else
+		} else {
 			$error = '';
+		}
 		EventLog::failure("Generating module '" . $module->moduleTitle . "' failed.", $error);
-		if ($args['deleteOnError'])
+		if ($args['deleteOnError'] ?? false) {
 			$module->delete();
-		else
+		} else {
 			$module->markFailed();
+		}
 	}
 
 	/**
 	 * (Re)generating a config module succeeded. Update db entry.
 	 *
-	 * @param array $args contains 'moduleid' and optionally 'deleteOnError' and 'tmpTgz'
+	 * @param array $args contains 'moduleid' and optionally 'tmpTgz'
 	 */
-	public static function generateSucceeded($args)
+	public static function generateSucceeded(array $args): void
 	{
 		if (!isset($args['moduleid']) || !is_numeric($args['moduleid'])) {
 			EventLog::warning('Ignoring generateSucceeded event as it has no moduleid assigned.');
 			return;
 		}
 		$module = self::get($args['moduleid']);
-		if ($module === false) {
+		if ($module === null) {
 			EventLog::warning('generateSucceeded callback for module id ' . $args['moduleid'] . ', but no instance could be generated.');
 			return;
 		}
-		if (isset($args['tmpTgz']))
-			$module->markUpdated($args['tmpTgz']);
-		else
-			$module->markUpdated(false);
+		$module->markUpdated($args['tmpTgz'] ?? null);
 	}
 
 }
diff --git a/modules-available/sysconfig/inc/configmodule/branding.inc.php b/modules-available/sysconfig/inc/configmodule/branding.inc.php
index 76968ff4..84f79b44 100644
--- a/modules-available/sysconfig/inc/configmodule/branding.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/branding.inc.php
@@ -17,10 +17,10 @@ class ConfigModule_Branding extends ConfigModule
 	
 	private $tmpFile = false;
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		if (!$this->validateConfig()) {
-			return $this->archive() !== false && file_exists($this->archive()); // No new temp file given, old archive still exists, pretend it worked...
+			return !empty($this->archive()) && file_exists($this->archive()); // No new temp file given, old archive still exists, pretend it worked...
 		}
 		return Taskmanager::submit('MoveFile', array(
 			'source' => $this->tmpFile,
@@ -30,17 +30,17 @@ class ConfigModule_Branding extends ConfigModule
 		));
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
 		return $this->tmpFile !== false && file_exists($this->tmpFile);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		if ($key !== 'tmpFile' || !is_string($value) || !file_exists($value))
 			return false;
@@ -48,12 +48,12 @@ class ConfigModule_Branding extends ConfigModule
 		return true;
 	}
 
-	public function getData($key)
+	public function getData(?string $key): bool
 	{
 		return false;
 	}
 
-	public function allowDownload()
+	public function allowDownload(): bool
 	{
 		return true;
 	}
diff --git a/modules-available/sysconfig/inc/configmodule/customodule.inc.php b/modules-available/sysconfig/inc/configmodule/customodule.inc.php
index 56aa9277..b5c10104 100644
--- a/modules-available/sysconfig/inc/configmodule/customodule.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/customodule.inc.php
@@ -16,12 +16,12 @@ class ConfigModule_CustomModule extends ConfigModule
 	
 	private $tmpFile = false;
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		if (!$this->validateConfig()) {
 			// No temp file given from wizard
 			// Old archive still exists? pretend it worked...
-			if ($this->archive() === false || !file_exists($this->archive()))
+			if ($this->archive() === '' || !file_exists($this->archive()))
 				return false;
 			if ($this->currentVersion() == 1) {
 				// Need an upgrade
@@ -42,17 +42,17 @@ class ConfigModule_CustomModule extends ConfigModule
 		));
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
 		return $this->tmpFile !== false && file_exists($this->tmpFile);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		// Sets the temp file from the wizard, where it stored the processed archive
 		if ($key !== 'tmpFile' || !file_exists($value))
@@ -61,12 +61,12 @@ class ConfigModule_CustomModule extends ConfigModule
 		return true;
 	}
 
-	public function getData($key)
+	public function getData(?string $key): bool
 	{
 		return false;
 	}
 
-	public function allowDownload()
+	public function allowDownload(): bool
 	{
 		return true;
 	}
diff --git a/modules-available/sysconfig/inc/configmodule/ldapauth.inc.php b/modules-available/sysconfig/inc/configmodule/ldapauth.inc.php
index 7af4671e..64af4c0e 100644
--- a/modules-available/sysconfig/inc/configmodule/ldapauth.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/ldapauth.inc.php
@@ -5,7 +5,7 @@ class ConfigModule_LdapAuth extends ConfigModuleBaseLdap
 
 	const MODID = 'LdapAuth';
 
-	protected function preTaskmanagerHook(&$config)
+	protected function preTaskmanagerHook(array &$config)
 	{
 		// Just set the flag so the taskmanager job knows we're dealing with a normal ldap server,
 		// not AD scheme
diff --git a/modules-available/sysconfig/inc/configmodule/screensaver.inc.php b/modules-available/sysconfig/inc/configmodule/screensaver.inc.php
index 08a2c9a1..1797331c 100644
--- a/modules-available/sysconfig/inc/configmodule/screensaver.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/screensaver.inc.php
@@ -14,7 +14,7 @@ class ConfigModule_Screensaver extends ConfigModule
 	const MODID = 'Screensaver';
 	const VERSION = 1;
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		/* Validate if all data are available */
 		if (!$this->validateConfig())
@@ -30,21 +30,20 @@ class ConfigModule_Screensaver extends ConfigModule
 		), false);
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
-		return isset($this->moduleData['qss']) &&
-				 isset($this->moduleData['texts']) &&
-			    isset($this->moduleData['texts']['text-idle-kill']) &&
-				 isset($this->moduleData['texts']['text-no-timeout']) &&
-				 isset($this->moduleData['texts']['text-shutdown']);
+		return isset($this->moduleData['texts']['text-no-timeout'])
+			&& isset($this->moduleData['texts']['text-idle-kill'])
+			&& isset($this->moduleData['texts']['text-shutdown'])
+			&& isset($this->moduleData['qss']);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		switch ($key) {
 		case 'qss':
@@ -58,17 +57,15 @@ class ConfigModule_Screensaver extends ConfigModule
 		return true;
 	}
 
-	public function allowDownload()
+	public function allowDownload(): bool
 	{
 		return false;
 	}
 
 	/**
 	 * Creates a map with filepath => file content
-	 *
-	 * @return array in the form of Map<String, byte[]>
 	 */
-	private function getFileArray()
+	private function getFileArray(): array
 	{
 		$files = array(
 			'/opt/openslx/xscreensaver/style.qss' => $this->moduleData['qss'],
@@ -98,7 +95,7 @@ class ConfigModule_Screensaver extends ConfigModule
 		return $files;
 	}
 
-	private function wrapHtmlTags($text_name)
+	private function wrapHtmlTags(string $text_name): string
 	{
 		return '<html><body>' . $this->moduleData['texts'][$text_name] . '</body></html>';
 	}
diff --git a/modules-available/sysconfig/inc/configmodule/sshconfig.inc.php b/modules-available/sysconfig/inc/configmodule/sshconfig.inc.php
index b5ab20e4..a62d1035 100644
--- a/modules-available/sysconfig/inc/configmodule/sshconfig.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/sshconfig.inc.php
@@ -14,7 +14,7 @@ class ConfigModule_SshConfig extends ConfigModule
 	const MODID = 'SshConfig';
 	const VERSION = 1;
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		if (!$this->validateConfig())
 			return false;
@@ -26,12 +26,12 @@ class ConfigModule_SshConfig extends ConfigModule
 		return Taskmanager::submit('SshdConfigGenerator', $config);
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
 		// UPGRADE
 		if (isset($this->moduleData['allowPasswordLogin']) && !isset($this->moduleData['allowedUsersLogin'])) {
@@ -45,7 +45,7 @@ class ConfigModule_SshConfig extends ConfigModule
 			&& isset($this->moduleData['listenPort']);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		switch ($key) {
 		case 'publicKey':
diff --git a/modules-available/sysconfig/inc/configmodule/sshkey.inc.php b/modules-available/sysconfig/inc/configmodule/sshkey.inc.php
index 2d212d25..e4a55ad7 100644
--- a/modules-available/sysconfig/inc/configmodule/sshkey.inc.php
+++ b/modules-available/sysconfig/inc/configmodule/sshkey.inc.php
@@ -14,7 +14,7 @@ class ConfigModule_SshKey extends ConfigModule
 	const MODID = 'SshKey';
 	const VERSION = 1;
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		if (!$this->validateConfig())
 			return false;
@@ -30,17 +30,17 @@ class ConfigModule_SshKey extends ConfigModule
 		return Taskmanager::submit('MakeTarball', $config);
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
 		return isset($this->moduleData['publicKey']);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		switch ($key) {
 		case 'publicKey':
diff --git a/modules-available/sysconfig/inc/configmodulebaseldap.inc.php b/modules-available/sysconfig/inc/configmodulebaseldap.inc.php
index e3d99025..770a40e6 100644
--- a/modules-available/sysconfig/inc/configmodulebaseldap.inc.php
+++ b/modules-available/sysconfig/inc/configmodulebaseldap.inc.php
@@ -11,7 +11,7 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 		'shareOther', 'shareHomeDrive', 'shareDomain', 'credentialPassthrough', 'mapping', 'genuid',
 		'ldapAttrMountOpts', 'shareHomeMountOpts', 'nohomewarn');
 
-	public static function getMapping($config = false, &$empty = true)
+	public static function getMapping(array $config = null, ?bool &$empty = true): array
 	{
 		$list = array(
 			['name' => 'uid', 'field' => 'uid', 'ad' => 'sAMAccountName'],
@@ -46,10 +46,10 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 	 *
 	 * @param string $command start, restart, check
 	 * @param bool|int|int[] $ids list of IDs to run command on, or false meaning "all"
-	 * @param string $parent if not NULL, this will be the parent task of the launch-task
+	 * @param string|null $parent if not NULL, this will be the parent task of the launch-task
 	 * @return boolean|string false on error, id of task otherwise
 	 */
-	public static function ldadp($command = 'start', $ids = false, $parent = null)
+	public static function ldadp(string $command = 'start', $ids = false, string $parent = null)
 	{
 		if ($ids === false) {
 			$ids = self::getActiveModuleIds();
@@ -67,7 +67,7 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 		return $task['id'];
 	}
 
-	protected function generateInternal($tgz, $parent)
+	protected function generateInternal(string $tgz, ?string $parent)
 	{
 		$config = $this->moduleData;
 		if (isset($config['certificate']) && !is_string($config['certificate'])) {
@@ -97,7 +97,7 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 		}
 		// This is now always on, as we mask it transparently in our lightdm greeter
 		$config['fixnumeric'] = 'true';
-		$config['genuid'] = isset($config['genuid']) && !empty($config['genuid']);
+		$config['genuid'] = !empty($config['genuid']);
 		$config['nohomewarn'] = isset($config['nohomewarn']) ? (int)$config['nohomewarn'] : 0;
 		$this->preTaskmanagerHook($config);
 		$task = Taskmanager::submit('CreateLdapConfig', $config);
@@ -111,25 +111,23 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 	 * Hook called before running CreateLdapConfig task with the
 	 * configuration to be passed to the task. Passed by reference
 	 * so it can be modified.
-	 *
-	 * @param array $config
 	 */
-	protected function preTaskmanagerHook(&$config)
+	protected function preTaskmanagerHook(array &$config)
 	{
 	}
 
-	protected function moduleVersion()
+	protected function moduleVersion(): int
 	{
 		return self::VERSION;
 	}
 
-	protected function validateConfig()
+	protected function validateConfig(): bool
 	{
 		// Check if required fields are filled
 		return ArrayUtil::hasAllKeys($this->moduleData, self::$REQUIRED_FIELDS);
 	}
 
-	public function setData($key, $value)
+	public function setData(string $key, $value): bool
 	{
 		if (!in_array($key, self::$REQUIRED_FIELDS) && !in_array($key, self::$OPTIONAL_FIELDS))
 			return false;
@@ -142,7 +140,7 @@ abstract class ConfigModuleBaseLdap extends ConfigModule
 	/**
 	 * Server IP changed - rebuild all AD modules.
 	 */
-	public function event_serverIpChanged()
+	public function event_serverIpChanged(): void
 	{
 		$this->generate(false);
 	}
diff --git a/modules-available/sysconfig/inc/configtgz.inc.php b/modules-available/sysconfig/inc/configtgz.inc.php
index 9ab3ffd3..8ac87908 100644
--- a/modules-available/sysconfig/inc/configtgz.inc.php
+++ b/modules-available/sysconfig/inc/configtgz.inc.php
@@ -4,25 +4,25 @@ class ConfigTgz
 {
 	
 	private $configId = 0;
-	private $configTitle = false;
-	private $file = false;
+	private $configTitle = '';
+	private $file = '';
 	private $modules = array();
 
 	private function __construct()
 	{
 	}
 
-	public function id()
+	public function id(): int
 	{
 		return $this->configId;
 	}
 	
-	public function title()
+	public function title(): string
 	{
 		return $this->configTitle;
 	}
 	
-	public function areAllModulesUpToDate()
+	public function areAllModulesUpToDate(): bool
 	{
 		if (!$this->configId > 0)
 			ErrorHandler::traceError('ConfigTgz::areAllModulesUpToDate called on un-inserted config.tgz!');
@@ -37,24 +37,29 @@ class ConfigTgz
 		return true;
 	}
 	
-	public function isActive()
+	public function isActive(): bool
 	{
 		return readlink(CONFIG_HTTP_DIR . '/default/config.tgz') === $this->file;
 	}
-	
-	public function getModuleIds()
+
+	/**
+	 * @return int[]
+	 */
+	public function getModuleIds(): array
 	{
-		$ret = array();
+		$ret = [];
 		foreach ($this->modules as $module) {
-			$ret[] = $module['moduleid'];
+			$ret[] = (int)$module['moduleid'];
 		}
 		return $ret;
 	}
-		
-	public function update($title, $moduleIds)
+
+	/**
+	 * @param string $title New title for module
+	 * @param int[] $moduleIds List of modules to include in this config
+	 */
+	public function update(string $title, array $moduleIds): void
 	{
-		if (!is_array($moduleIds))
-			return false;
 		if (!empty($title)) {
 			$this->configTitle = $title;
 		}
@@ -82,20 +87,19 @@ class ConfigTgz
 			'status' => 'OUTDATED',
 			'now' => time(),
 		));
-		return true;
 	}
 	
 	/**
 	 * 
-	 * @param bool $deleteOnError
-	 * @param int $timeoutMs
-	 * @param string|null $parentTask parent task to order this rebuild after
+	 * @param bool $deleteOnError Delete this config in case of error?
+	 * @param int $timeoutMs max time to wait for completion
+	 * @param string|null $parentTask parent task to order this (re)build after
 	 * @return string|bool true=success, false=error, string=taskid, still running
 	 */
-	public function generate($deleteOnError = false, $timeoutMs = 0, $parentTask = null)
+	public function generate(bool $deleteOnError = false, int $timeoutMs = 0, ?string $parentTask = null)
 	{
-		if (!($this->configId > 0) || !is_array($this->modules) || $this->file === false)
-			ErrorHandler::traceError('configId <= 0 or modules not array in ConfigTgz::rebuild()');
+		if (!($this->configId > 0) || empty($this->file))
+			ErrorHandler::traceError('configId <= 0 or no file in ConfigTgz::rebuild()');
 		$files = array();
 		// Get all config modules for system config
 		foreach ($this->modules as $module) {
@@ -140,11 +144,12 @@ class ConfigTgz
 		$ret = Database::exec("DELETE FROM configtgz WHERE configid = :configid LIMIT 1",
 				['configid' => $this->configId], true);
 		if ($ret !== false) {
-			if ($this->file !== false)
+			if (!empty($this->file)) {
 				Taskmanager::submit('DeleteFile', array('file' => $this->file), true);
+			}
 			$this->configId = 0;
-			$this->modules = false;
-			$this->file = false;
+			$this->modules = [];
+			$this->file = '';
 		}
 		return $ret !== false;
 	}
@@ -156,7 +161,7 @@ class ConfigTgz
 		$this->mark('OUTDATED');
 	}
 	
-	private function markUpdated($task): void
+	private function markUpdated(array $task): void
 	{
 		if ($this->configId === 0)
 			ErrorHandler::traceError('ConfigTgz::markUpdated called with invalid config id!');
@@ -194,7 +199,7 @@ class ConfigTgz
 	{
 		if ($this->configId === 0)
 			ErrorHandler::traceError('ConfigTgz::markFailed called with invalid config id!');
-		if ($this->file === false || !file_exists($this->file)) {
+		if (empty($this->file) || !file_exists($this->file)) {
 			$this->mark('MISSING');
 		} else {
 			$this->mark('OUTDATED');
@@ -218,12 +223,12 @@ class ConfigTgz
 	 * @param string $destFile where to store final result
 	 * @return false|array taskmanager task
 	 */
-	private static function recompress($files, $destFile, $parentTask = null)
+	private static function recompress(array $files, string $destFile, $parentTask = null)
 	{
 		// Get stuff other modules want to inject
 		$handler = function($hook) {
 			include $hook->file;
-			return isset($file) ? $file : false;
+			return $file ?? false;
 		};
 		foreach (Hook::load('config-tgz') as $hook) {
 			$file = $handler($hook);
@@ -246,7 +251,7 @@ class ConfigTgz
 	 * on each one. This mostly makes sense to call if a global module
 	 * that is injected via a hook has changed.
 	 */
-	public static function rebuildAllConfigs()
+	public static function rebuildAllConfigs(): void
 	{
 		Database::exec("UPDATE configtgz SET status = :status", array(
 			'status' => 'OUTDATED'
@@ -254,7 +259,7 @@ class ConfigTgz
 		$res = Database::simpleQuery("SELECT configid FROM configtgz");
 		foreach ($res as $row) {
 			$configTgz = self::get($row['configid']);
-			if ($configTgz !== false) {
+			if ($configTgz !== null) {
 				$configTgz->generate();
 			}
 		}
@@ -263,12 +268,10 @@ class ConfigTgz
 	/**
 	 * @param string $title Title of config
 	 * @param int[] $moduleIds Modules to include in config
-	 * @return false|ConfigTgz The module instance, false on error
+	 * @return ConfigTgz The module instance
 	 */
-	public static function insert($title, $moduleIds)
+	public static function insert(string $title, array $moduleIds): ConfigTgz
 	{
-		if (!is_array($moduleIds))
-			return false;
 		$instance = new ConfigTgz;
 		$instance->configTitle = $title;
 		// Create output file name (config.tgz)
@@ -300,53 +303,53 @@ class ConfigTgz
 		return $instance;
 	}
 
-	public static function get($configId)
+	/**
+	 * @param array{configid: int, title:  string, filepath: string} $row Input data, fields mandatory
+	 */
+	private static function instanceFromRow(array $row): ConfigTgz
 	{
-		$ret = Database::queryFirst("SELECT configid, title, filepath FROM configtgz WHERE configid = :configid", array(
-			'configid' => $configId
-		));
-		if ($ret === false)
-			return false;
 		$instance = new ConfigTgz;
-		$instance->configId = $ret['configid'];
-		$instance->configTitle = $ret['title'];
-		$instance->file = $ret['filepath'];
-		$ret = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_x_module "
+		$instance->configId = $row['configid'];
+		$instance->configTitle = $row['title'];
+		$instance->file = $row['filepath'];
+		$innerRes = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_x_module "
 			. " INNER JOIN configtgz_module USING (moduleid) "
 			. " WHERE configid = :configid", array('configid' => $instance->configId));
 		$instance->modules = array();
-		foreach ($ret as $row) {
-			$instance->modules[] = $row;
+		foreach ($innerRes as $innerRow) {
+			$instance->modules[] = $innerRow;
 		}
 		return $instance;
 	}
 
+	public static function get(int $configId): ?ConfigTgz
+	{
+		$ret = Database::queryFirst("SELECT configid, title, filepath FROM configtgz WHERE configid = :configid", array(
+			'configid' => $configId
+		));
+		if ($ret === false)
+			return null;
+		return self::instanceFromRow($ret);
+	}
+
 	/**
 	 * @param int $moduleId ID of config module
-	 * @return ConfigTgz[]|false
+	 * @return ConfigTgz[]
 	 */
-	public static function getAllForModule($moduleId)
+	public static function getAllForModule(int $moduleId): array
 	{
 		$res = Database::simpleQuery("SELECT configid, title, filepath FROM configtgz_x_module "
 			. " INNER JOIN configtgz USING (configid) "
 			. " WHERE moduleid = :moduleid", array(
 			'moduleid' => $moduleId
 		));
-		if ($res === false)
-			return false;
+		if ($res === false) {
+			EventLog::warning('ConfigTgz::getAllForModule failed: ' . Database::lastError());
+			return [];
+		}
 		$list = array();
 		foreach ($res as $row) {
-			$instance = new ConfigTgz;
-			$instance->configId = $row['configid'];
-			$instance->configTitle = $row['title'];
-			$instance->file = $row['filepath'];
-			$innerRes = Database::simpleQuery("SELECT moduleid, moduletype, filepath, status FROM configtgz_x_module "
-				. " INNER JOIN configtgz_module USING (moduleid) "
-				. " WHERE configid = :configid", array('configid' => $instance->configId));
-			$instance->modules = array();
-			foreach ($innerRes as $innerRow) {
-				$instance->modules[] = $innerRow;
-			}
+			$instance = self::instanceFromRow($row);
 			$list[] = $instance;
 		}
 		return $list;
@@ -356,31 +359,32 @@ class ConfigTgz
 	 * Called when (re)generating a config tgz failed, so we can
 	 * update the status in the DB and add a server log entry.
 	 *
-	 * @param array $task
 	 * @param array $args contains 'configid' and optionally 'deleteOnError'
 	 */
-	public static function generateFailed($task, $args)
+	public static function generateFailed(array $task, array $args): void
 	{
 		if (!isset($args['configid']) || !is_numeric($args['configid'])) {
 			EventLog::warning('Ignoring generateFailed event as it has no configid assigned.');
 			return;
 		}
 		$config = self::get($args['configid']);
-		if ($config === false) {
+		if ($config === null) {
 			EventLog::warning('generateFailed callback for config id ' . $args['configid'] . ', but no instance could be generated.');
 			return;
 		}
-		if (isset($task['data']['error']))
+		if (isset($task['data']['error'])) {
 			$error = $task['data']['error'];
-		elseif (isset($task['data']['messages']))
+		} elseif (isset($task['data']['messages'])) {
 			$error = $task['data']['messages'];
-		else
+		} else {
 			$error = '';
+		}
 		EventLog::failure("Generating config.tgz '" . $config->configTitle . "' failed.", $error);
-		if ($args['deleteOnError'])
+		if ($args['deleteOnError']) {
 			$config->delete();
-		else
+		} else {
 			$config->markFailed();
+		}
 	}
 
 	/**
@@ -389,14 +393,14 @@ class ConfigTgz
 	 * @param array $task the task object
 	 * @param array $args contains 'configid' and optionally 'deleteOnError'
 	 */
-	public static function generateSucceeded($task, $args)
+	public static function generateSucceeded(array $task, array $args): void
 	{
 		if (!isset($args['configid']) || !is_numeric($args['configid'])) {
 			EventLog::warning('Ignoring generateSucceeded event as it has no configid assigned.');
 			return;
 		}
 		$config = self::get($args['configid']);
-		if ($config === false) {
+		if ($config === null) {
 			EventLog::warning('generateSucceeded callback for config id ' . $args['configid'] . ', but no instance could be generated.');
 			return;
 		}
diff --git a/modules-available/sysconfig/inc/ldap.inc.php b/modules-available/sysconfig/inc/ldap.inc.php
index 349a662e..e974a8a3 100644
--- a/modules-available/sysconfig/inc/ldap.inc.php
+++ b/modules-available/sysconfig/inc/ldap.inc.php
@@ -3,7 +3,7 @@
 class Ldap
 {
 
-	public static function normalizeDn($dn)
+	public static function normalizeDn(string $dn): string
 	{
 		return trim(preg_replace('/[,;]\s*/', ',', $dn));
 	}
diff --git a/modules-available/sysconfig/inc/ppd.inc.php b/modules-available/sysconfig/inc/ppd.inc.php
index 75608c56..c28e0355 100644
--- a/modules-available/sysconfig/inc/ppd.inc.php
+++ b/modules-available/sysconfig/inc/ppd.inc.php
@@ -247,8 +247,8 @@ class Ppd
 	private $data;
 	private $dataLen;
 
-	private $error;
-	private $warnings;
+	private $error = null;
+	private $warnings = [];
 
 	private $knownKeywordMalformed;
 
@@ -301,7 +301,7 @@ class Ppd
 		$this->dataLen = strlen($this->data);
 		$this->encoder = false;
 		$this->sourceEncoding = false;
-		$this->error = false;
+		$this->error = null;
 		$this->warnings = array();
 		$this->knownKeywordMalformed = false;
 		$this->settings = array();
@@ -309,8 +309,8 @@ class Ppd
 
 		// Parse
 		/* @var PpdOption $rawOption */
-		/* @var PpdBlockInternal $currentBlock */
-		$currentBlock = false;
+		/* @var ?PpdBlockInternal $currentBlock */
+		$currentBlock = null;
 		$inRawBlock = false; // True if in a multi-line InvocationValue or QuotedValue (3.6: Parsing Summary for Values)
 		$wantsEnd = false;
 		// For now we ignore values mostly while parsing. The spec says that InvocationValues must only contain printable
@@ -318,7 +318,7 @@ class Ppd
 		$lStart = -1;
 		$lEnd = -1;
 		$no = 0;
-		while ($lStart < $this->dataLen && $lEnd !== false) {
+		while ($lStart < $this->dataLen) {
 			unset($mainKeyword, $optionKeyword, $optionTranslation, $option, $value, $valueTranslation);
 			if ($no !== 0 && $this->data[$lEnd] === "\r" && $this->data[$lEnd + 1] === "\n") {
 				$lEnd++;
@@ -332,6 +332,8 @@ class Ppd
 			}
 			$lStart = $lEnd + 1;
 			$lEnd = $this->nextLineEnd($lStart);
+			if ($lEnd === null)
+				break;
 			$no++;
 			// Validate
 			$len = $lEnd - $lStart;
@@ -343,7 +345,7 @@ class Ppd
 				$this->warn($no, 'Exceeds length of 255');
 			}
 			if (!$inRawBlock && preg_match_all('/[^\x09\x0A\x0D\x20-\xFF]/', $line, $out)) {
-				$chars = $this->escapeBinaryArray($out[0]);
+				$chars = self::escapeBinaryArray($out[0]);
 				$this->warn($no, 'Contains invalid character(s) ' . $chars);
 			}
 			// Handle
@@ -379,7 +381,7 @@ class Ppd
 					continue;
 				}
 				$parts = preg_split('/\s*:\s*/', $line, 2); // TODO: UIConstrains
-				if (count($parts) !== 2) {
+				if (!is_array($parts) || count($parts) !== 2) {
 					$this->warn($no, 'No colon found; not in "key [option]: value" format, ignoring line');
 					continue;
 				}
@@ -390,9 +392,10 @@ class Ppd
 					continue;
 				}
 				$mainKeyword = $out[1];
-				$optionKeyword = isset($out[3]) ? $out[3] : false;
+				$optionKeyword = $out[3] ?? null;
 				$optionTranslation = isset($out[4]) ? $this->unhexTranslation($no, substr($out[4], 1)) : $optionKeyword; // If no translation given, fallback to option
 				// 3b) Handle value
+				/** @var string $value */
 				$value = $parts[1];
 				if ($value[0] === '"') {
 					// Start of InvocationValue or QuotedValue
@@ -419,17 +422,17 @@ class Ppd
 				// Key-value-pair parsed, now the fun part
 				// Special cases for opening closing certain groups
 				if ($mainKeyword === 'OpenGroup') {
-					if ($currentBlock !== false) {
+					if ($currentBlock !== null) {
 						$this->error = 'Line ' . $no . ': OpenGroup while other block (type=' . $currentBlock->type
 							. ', id=' . $currentBlock->id . ') was not closed yet';
 						return;
 					}
 					// TODO: Check unique
-					$nb = new PpdBlockInternal($value, $valueTranslation, 'Group', false, $lStart);
+					$nb = new PpdBlockInternal($value, $valueTranslation, 'Group', null, $lStart);
 					$currentBlock = $nb;
 					continue;
 				} elseif ($mainKeyword === 'OpenSubGroup') {
-					if ($currentBlock === false || $currentBlock->type !== 'Group') {
+					if ($currentBlock === null || $currentBlock->type !== 'Group') {
 						$this->error = 'Line ' . $no . ': OpenSubGroup with no preceding OpenGroup';
 						return;
 					}
@@ -445,12 +448,12 @@ class Ppd
 					} else {
 						$type = substr($type, 4);
 					}
-					if ($currentBlock !== false && $currentBlock->isUi()) {
+					if ($currentBlock !== null && $currentBlock->isUi()) {
 						$this->error = 'Line ' . $no . ': ' . $mainKeyword . ' while previous ' . $type . ' "'
 							. $currentBlock->id . '" was not closed yet';
 						return;
 					}
-					if ($optionKeyword === false) {
+					if ($optionKeyword === null) {
 						$this->error = 'Line ' . $no . ': ' . $mainKeyword . ' with no option keyword';
 						return;
 					}
@@ -459,9 +462,10 @@ class Ppd
 						return;
 					}
 					// TODO: Check unique
-					$nb = new PpdBlockInternal($optionKeyword, $optionTranslation, $type, $currentBlock, $lStart);
+					$nb = new PpdBlockInternal($optionKeyword, $optionTranslation ?? $optionKeyword,
+						$type, $currentBlock, $lStart);
 					$nb->value = $value;
-					if ($currentBlock !== false) {
+					if ($currentBlock !== null) {
 						$currentBlock->childBlocks[] = $nb;
 					}
 					$currentBlock = $nb;
@@ -476,7 +480,7 @@ class Ppd
 					} else {
 						$type = substr($type, 5);
 					}
-					if ($currentBlock === false) {
+					if ($currentBlock === null) {
 						$this->error = 'Line ' . $no . ': ' . $mainKeyword . ' with no Open' . $type;
 						return;
 					}
@@ -493,7 +497,7 @@ class Ppd
 					$currentBlock = $currentBlock->parent;
 					continue;
 				} elseif ($mainKeyword === 'OrderDependency') {
-					if ($currentBlock === false || $currentBlock->isUi()) {
+					if ($currentBlock === null || $currentBlock->isUi()) {
 						$this->warn($no, 'OrderDependency outside OpenUI/CloseUI block');
 					}
 					continue;
@@ -519,7 +523,7 @@ class Ppd
 					} else {
 						$this->requiredKeywords[$mainKeyword] = array($value);
 					}
-					if (($err = $this->validateLine($this->REQUIRED_KEYWORDS[$mainKeyword], $optionKeyword, $value)) !== true) {
+					if (($err = Ppd::validateLine($this->REQUIRED_KEYWORDS[$mainKeyword], $optionKeyword, $value)) !== true) {
 						$this->warn($no, 'Required main keyword ' . $mainKeyword . ': ' . $err);
 						$this->knownKeywordMalformed = true;
 					}
@@ -527,7 +531,7 @@ class Ppd
 				}
 				// Other well known keywords
 				if (isset($this->KNOWN_KEYWORDS[$mainKeyword])) {
-					if (($err = $this->validateLine($this->KNOWN_KEYWORDS[$mainKeyword], $optionKeyword, $value)) !== true) {
+					if (($err = Ppd::validateLine($this->KNOWN_KEYWORDS[$mainKeyword], $optionKeyword, $value)) !== true) {
 						$this->warn($no, 'Known main keyword ' . $mainKeyword . ': ' . $err);
 						$this->knownKeywordMalformed = true;
 					}
@@ -539,16 +543,16 @@ class Ppd
 					continue;
 				}
 				if (substr($mainKeyword, 0, 17) === 'FoomaticRIPOption') {
-					if ($optionKeyword === false) {
+					if ($optionKeyword === null) {
 						$this->warn($no, "$mainKeyword with no option keyword");
-					} elseif ($currentBlock !== false && isset($this->settings[$optionKeyword])) {
+					} elseif ($currentBlock !== null && isset($this->settings[$optionKeyword])) {
 						$option = $this->getOption($optionKeyword, $currentBlock);
 						$option->foomatic[substr($mainKeyword, 11)] = new PpdOption($lStart, $len, $value, $valueTranslation);
 					} else {
 						$this->warn($no, 'TODO: ' . $line);
 					}
 				} elseif (substr($mainKeyword, 0, 6) === 'Custom') {
-					if ($optionKeyword === false) {
+					if ($optionKeyword === null) {
 						$this->warn($no, "$mainKeyword with no option keyword");
 					} elseif ($optionKeyword !== 'True') {
 						$this->warn($no, "$mainKeyword with option keyword other than 'True'; ignored");
@@ -557,7 +561,7 @@ class Ppd
 						$option->custom = new PpdOption($lStart, $len, $value, $valueTranslation);
 					}
 				} elseif (substr($mainKeyword, 0, 11) === 'ParamCustom') {
-					if ($optionKeyword === false) {
+					if ($optionKeyword === null) {
 						$this->warn($no, "$mainKeyword with no option keyword");
 					} elseif (substr($mainKeyword, 11) !== $optionKeyword) {
 						$this->warn($no, "Don't know how to handle $mainKeyword with option keyword $optionKeyword "
@@ -568,18 +572,18 @@ class Ppd
 					}
 				} elseif ($mainKeyword[0] === '?') {
 					// Ignoring option query for now
-				} elseif ($optionKeyword === false && !isset($this->KNOWN_KEYWORDS[$mainKeyword])) {
+				} elseif ($optionKeyword === null && !isset($this->KNOWN_KEYWORDS[$mainKeyword])) {
 					// Must be a definition for an option
 					$this->warn($no, "Don't know how to handle line with main keyword '$mainKeyword', no option keyword found.");
 				} else {
 					// Some option for some option ;)
-					if ($optionKeyword === false) {
+					if ($optionKeyword === null) {
 						// We know that this is a known main keyword otherwise we would have hit the previous elseif block
 						$optionKeyword = $value;
 						$optionTranslation = $valueTranslation;
 					}
 					$option = $this->getOption($mainKeyword, $currentBlock);
-					$optionInstance = new PpdOption($lStart, $len, $optionKeyword, $optionTranslation);
+					$optionInstance = new PpdOption($lStart, $len, $optionKeyword, $optionTranslation ?? $optionKeyword);
 					if ($this->binary_in_array($mainKeyword, $this->REPEATED_KEYWORDS)) {
 						// This can occur multiple times, just pile them up
 						$option->values[] = $optionInstance;
@@ -602,7 +606,7 @@ class Ppd
 			}
 		} // end while loop over ppd contents
 		//
-		if ($currentBlock !== false) {
+		if ($currentBlock !== null) {
 			$this->error = 'Block ' . $currentBlock->id . ' (' . $currentBlock->type . ') was never closed.';
 			return;
 		}
@@ -612,11 +616,11 @@ class Ppd
 				$this->error = 'One or more required keywords missing';
 			}
 		}
-		if ($this->error !== false) {
+		if ($this->error !== null) {
 			return;
 		}
 		// All required keywords exist
-		if (preg_match('/utf\-?8/i', $this->requiredKeywords['LanguageEncoding'][0])) {
+		if (preg_match('/utf-?8/i', $this->requiredKeywords['LanguageEncoding'][0])) {
 			$this->sourceEncoding = false; // Would be a NOOP
 		} elseif (isset($this->ENCODINGS[$this->requiredKeywords['LanguageEncoding'][0]])) {
 			$this->sourceEncoding = $this->ENCODINGS[$this->requiredKeywords['LanguageEncoding'][0]];
@@ -666,10 +670,10 @@ class Ppd
 		}
 	}
 
-	private function nextLineEnd($start)
+	private function nextLineEnd(int $start): ?int
 	{
 		if ($start >= $this->dataLen)
-			return false;
+			return null;
 		while ($start < $this->dataLen) {
 			$char = $this->data[$start];
 			if ($char === "\r" || $char === "\n")
@@ -679,26 +683,26 @@ class Ppd
 		return $this->dataLen;
 	}
 
-	private function warn($lineNo, $message)
+	private function warn(int $lineNo, string $message): void
 	{
 		$line = 'Line ' . $lineNo . ': ' . $message;
 		$this->warnings[] = $line;
 	}
 
-	private function escapeBinaryArray($array)
+	private static function escapeBinaryArray(array $array): string
 	{
 		return array_reduce(array_unique($array), function ($carry, $item) {
 			return $carry . '\x' . dechex(ord($item));
 		}, '');
 	}
 
-	private function unhexTranslation($lineNo, $translation)
+	private function unhexTranslation(int $lineNo, string $translation): string
 	{
 		if (strpos($translation, '<') === false)
 			return $translation;
 		return preg_replace_callback('/<[^>]*>/', function ($match) use ($lineNo) {
 			if (preg_match_all('/[^a-fA-F0-9\<\>\s]/', $match[0], $out)) {
-				$this->warn($lineNo, 'Invalid character(s) in hex substring: ' . $this->escapeBinaryArray($out[0]));
+				$this->warn($lineNo, 'Invalid character(s) in hex substring: ' . self::escapeBinaryArray($out[0]));
 			}
 			$string = preg_replace('/[^a-fA-F0-9]/', '', $match[0]);
 			if (strlen($string) % 2 !== 0) {
@@ -709,7 +713,7 @@ class Ppd
 		}, $translation);
 	}
 
-	private function hexTranslation($translation)
+	private function hexTranslation(string $translation): string
 	{
 		return preg_replace_callback('/[\x00-\x1f\x7b-\xff\:\<\>]+/', function ($match) {
 			return '<' . unpack('H*', $match[0])[1] . '>';
@@ -720,23 +724,23 @@ class Ppd
 	 * Get option object
 	 *
 	 * @param string $name option name
-	 * @param \PpdBlockInternal $block which block this option is defined in
-	 * @return \PpdSettingInternal the option object
+	 * @param ?PpdBlockInternal $block which block this option is defined in
+	 * @return PpdSettingInternal the option object
 	 */
-	private function getOption($name, $block = false)
+	private function getOption(string $name, ?PpdBlockInternal $block = null): PpdSettingInternal
 	{
 		if (!isset($this->settings[$name])) {
 			$this->settings[$name] = new PpdSettingInternal();
 			$this->settings[$name]->block = $block;
-		} elseif ($block !== false) {
-			if ($this->settings[$name]->block === false || $block->isChildOf($this->settings[$name]->block)) {
+		} elseif ($block !== null) {
+			if ($this->settings[$name]->block === null || $block->isChildOf($this->settings[$name]->block)) {
 				$this->settings[$name]->block = $block;
 			}
 		}
 		return $this->settings[$name];
 	}
 
-	private function binary_in_array($elem, $array)
+	private function binary_in_array($elem, $array): bool
 	{
 		$top = sizeof($array) - 1;
 		$bot = 0;
@@ -751,7 +755,7 @@ class Ppd
 		return false;
 	}
 
-	private function validateLine($validator, $option, $value)
+	private static function validateLine($validator, ?string $option, string $value)
 	{
 		if (is_array($validator)) {
 			$oExp = $validator[0];
@@ -776,7 +780,7 @@ class Ppd
 		return true;
 	}
 
-	private function getEolChar()
+	private function getEolChar(): string
 	{
 		$rn = substr_count("\r\n", $this->data);
 		$r = substr_count("\r", $this->data) - $rn;
@@ -795,21 +799,21 @@ class Ppd
 	 *
 	 */
 
-	public function getError()
+	public function getError(): ?string
 	{
 		return $this->error;
 	}
 
-	public function getWarnings()
+	public function getWarnings(): array
 	{
 		return $this->warnings;
 	}
 
-	public function getUISettings()
+	public function getUISettings(): array
 	{
 		$result = array();
 		foreach ($this->settings as $mk => $option) {
-			$isUi = ($option->block !== false && $option->block->isUi()) || isset($this->UI_KEYWORDS[$mk]);
+			$isUi = ($option->block !== null && $option->block->isUi()) || isset($this->UI_KEYWORDS[$mk]);
 			if ($isUi) {
 				$result[] = $mk;
 			}
@@ -817,30 +821,30 @@ class Ppd
 		return $result;
 	}
 
-	public function getSetting($name)
+	public function getSetting(string $name): ?PpdSetting
 	{
 		if (!isset($this->settings[$name]))
-			return false;
+			return null;
 		return new PpdSetting($this->settings[$name], isset($this->UI_KEYWORDS[$name]), $this->encoder);
 	}
 
-	public function removeSetting($name)
+	public function removeSetting(string $name): bool
 	{
 		if (!isset($this->settings[$name]))
 			return false;
 		$setting = $this->settings[$name];
 		$ranges = array();
-		$this->mergeRanges($ranges, $setting->default);
-		$this->mergeRanges($ranges, $setting->custom);
-		$this->mergeRanges($ranges, $setting->customParam);
+		Ppd::mergeRangesFromOption($ranges, $setting->default);
+		Ppd::mergeRangesFromOption($ranges, $setting->custom);
+		Ppd::mergeRangesFromOption($ranges, $setting->customParam);
 		foreach ($setting->foomatic as $obj) {
-			$this->mergeRanges($ranges, $obj);
+			Ppd::mergeRangesFromOption($ranges, $obj);
 		}
 		foreach ($setting->values as $obj) {
-			$this->mergeRanges($ranges, $obj);
+			Ppd::mergeRangesFromOption($ranges, $obj);
 		}
-		if ($setting->block !== false && $setting->block->isUi()) {
-			$this->mergeRanges($ranges, $setting->block->start, $setting->block->end);
+		if ($setting->block !== null && $setting->block->isUi()) {
+			Ppd::mergeRanges($ranges, $setting->block->start, $setting->block->end);
 		}
 		$tmp = array_map(function ($e) { return $e[0]; }, $ranges);
 		array_multisort($tmp, SORT_NUMERIC, $ranges);
@@ -859,10 +863,10 @@ class Ppd
 		$new .= substr($this->data, $last);
 		$this->data = $new;
 		$this->parse();
-		return $this->error === false;
+		return $this->error === null;
 	}
 
-	public function addEmptyOption($settingName, $option, $translation = false, $prepend = true)
+	public function addEmptyOption(string $settingName, string $option, string $translation = null, bool $prepend = true): bool
 	{
 		if (!isset($this->settings[$settingName]))
 			return false;
@@ -870,15 +874,15 @@ class Ppd
 		$pos = false;
 		if (!empty($setting->values)) {
 			if ($prepend) {
-				$pos = array_reduce($setting->values, function ($carry, $option) { return min($carry, $option->lineOffset); }, PHP_INT_MAX);
+				$pos = array_reduce($setting->values, function (int $carry, PpdOption $option) { return min($carry, $option->lineOffset); }, PHP_INT_MAX);
 			} else {
-				$pos = array_reduce($setting->values, function ($carry, $option) { return max($carry, $option->lineOffset); }, 0);
+				$pos = array_reduce($setting->values, function (int $carry, PpdOption $option) { return max($carry, $option->lineOffset); }, 0);
 			}
-		} elseif ($setting->default !== false) {
+		} elseif ($setting->default !== null) {
 			$pos = $setting->default->lineOffset;
-		} elseif ($setting->block !== false && $setting->block->isUi()) {
+		} elseif ($setting->block !== null && $setting->block->isUi()) {
 			$pos = $this->nextLineEnd($setting->block->start);
-			while ($pos !== false && $pos < $this->dataLen && ($this->data[$pos] === "\r" || $this->data[$pos] === "\n")) {
+			while ($pos !== null && $pos < $this->dataLen && ($this->data[$pos] === "\r" || $this->data[$pos] === "\n")) {
 				$pos++;
 			}
 		}
@@ -886,23 +890,23 @@ class Ppd
 			return false;
 		}
 		$line = '*' . $settingName . ' ' . $option;
-		if ($translation !== false) {
+		if ($translation !== null) {
 			$line .= '/' . $this->hexTranslation(($this->encoder)($translation, true));
 		}
 		$eol = $this->getEolChar();
 		$line .= ': ""' . $eol;
 		$this->data = substr($this->data, 0, $pos) . $line . substr($this->data, $pos);
 		$this->parse();
-		return $this->error === false;
+		return $this->error === null;
 	}
 
-	public function setDefaultOption($settingName, $optionName)
+	public function setDefaultOption($settingName, $optionName): bool
 	{
 		if (!isset($this->settings[$settingName]))
 			return false;
 		$setting = $this->settings[$settingName];
 		$line = '*Default' . $settingName . ': ' . $optionName;
-		if ($setting->default !== false) {
+		if ($setting->default !== null) {
 			$start = $setting->default->lineOffset;
 			$end = $start + $setting->default->lineLen;
 		} elseif (empty($setting->values)) {
@@ -914,22 +918,21 @@ class Ppd
 		}
 		$this->data = substr($this->data, 0, $start) . $line . substr($this->data, $end);
 		$this->parse();
-		return $this->error === false;
+		return $this->error === null;
 	}
 
-	public function write($file)
+	public function write(string $file)
 	{
 		return file_put_contents($file, $this->data);
 	}
 
-	private function mergeRanges(&$ranges, $start, $end = false)
+	private static function mergeRangesFromOption(array &$ranges, PpdOption $option): void
+	{
+		self::mergeRanges($ranges, $option->lineOffset, $option->lineOffset + $option->lineLen);
+	}
+
+	private static function mergeRanges(array &$ranges, int $start, int $end): void
 	{
-		if (is_object($start) && get_class($start) === 'PpdOption') {
-			$end = $start->lineOffset + $start->lineLen;
-			$start = $start->lineOffset;
-		}
-		if ($start === false || $end === false)
-			return;
 		if ($start >= $end)
 			return; // Don't even bother
 		foreach (array_keys($ranges) as $key) {
@@ -961,7 +964,7 @@ class Ppd
 	/**
 	 * @return bool whether there was at least one known option with format restriction violated.
 	 */
-	public function hasInvalidOption()
+	public function hasInvalidOption(): bool
 	{
 		return $this->knownKeywordMalformed;
 	}
@@ -1009,15 +1012,13 @@ class PpdSetting
 
 	/**
 	 * PpdSetting constructor.
-	 *
-	 * @param \PpdSettingInternal $setting
 	 */
-	public function __construct($setting, $isUi, $enc)
+	public function __construct(PpdSettingInternal $setting, bool $isUi, callable $enc)
 	{
-		if ($setting->default !== false) {
+		if ($setting->default !== null) {
 			$this->default = $setting->default->option;
 		}
-		if ($setting->block !== false && $setting->block->isUi()) {
+		if ($setting->block !== null && $setting->block->isUi()) {
 			$this->uiOptionType = $setting->block->value;
 			$this->uiOptionTranslation = $enc($setting->block->translation);
 			$this->isUi = true;
@@ -1051,9 +1052,9 @@ class PpdSetting
 class PpdSettingInternal
 {
 	/**
-	 * @var \PpdOption
+	 * @var ?PpdOption
 	 */
-	public $default = false;
+	public $default = null;
 	/**
 	 * @var \PpdOption[]
 	 */
@@ -1063,17 +1064,17 @@ class PpdSettingInternal
 	 */
 	public $foomatic = array();
 	/**
-	 * @var \PpdOption
+	 * @var ?PpdOption
 	 */
-	public $custom = false;
+	public $custom = null;
 	/**
-	 * @var \PpdOption
+	 * @var ?PpdOption
 	 */
-	public $customParam = false;
+	public $customParam = null;
 	/**
-	 * @var \PpdBlockInternal the innermost block this option resides in
+	 * @var ?PpdBlockInternal the innermost block this option resides in
 	 */
-	public $block = false;
+	public $block = null;
 }
 
 class PpdOption
@@ -1084,7 +1085,7 @@ class PpdOption
 	public $lineLen;
 	public $multiLine = false;
 
-	public function __construct($lineOffset, $lineLen, $option, $optionTranslation)
+	public function __construct(int $lineOffset, int $lineLen, string $option, string $optionTranslation)
 	{
 		$this->option = $option;
 		$this->optionTranslation = $optionTranslation;
@@ -1106,9 +1107,9 @@ class PpdBlockInternal
 	 */
 	public $childBlocks = array();
 	/**
-	 * @var PpdBlockInternal|false
+	 * @var ?PpdBlockInternal
 	 */
-	public $parent;
+	public $parent = null;
 
 	/**
 	 * @var int start byte in ppd
@@ -1116,16 +1117,16 @@ class PpdBlockInternal
 	public $start;
 
 	/**
-	 * @var int|bool end byte in ppd, false if block is not closed
+	 * @var ?int end byte in ppd, null if block is not closed
 	 */
-	public $end = false;
+	public $end = null;
 
 	/**
 	 * @var string value of opening line for block, e.g. 'PickOne' for OpenUI
 	 */
-	public $value = false;
+	public $value = '';
 
-	public function __construct($id, $translation, $type, $parent, $start)
+	public function __construct(string $id, string $translation, string $type, ?PpdBlockInternal $parent, int $start)
 	{
 		$this->id = $id;
 		$this->translation = $translation;
@@ -1137,7 +1138,7 @@ class PpdBlockInternal
 	/**
 	 * @return bool true if this is a UI block
 	 */
-	public function isUi()
+	public function isUi(): bool
 	{
 		return $this->type == 'UI' || $this->type === 'JCLUI';
 	}
@@ -1146,7 +1147,7 @@ class PpdBlockInternal
 	 * @param PpdBlockInternal $block some other PpdBlock instance
 	 * @return bool true if this is a child of $block
 	 */
-	public function isChildOf(PpdBlockInternal $block)
+	public function isChildOf(PpdBlockInternal $block): bool
 	{
 		$parent = $this->parent;
 		while ($parent !== false) {
diff --git a/modules-available/sysconfig/inc/sysconfig.inc.php b/modules-available/sysconfig/inc/sysconfig.inc.php
index 02131366..09860c7d 100644
--- a/modules-available/sysconfig/inc/sysconfig.inc.php
+++ b/modules-available/sysconfig/inc/sysconfig.inc.php
@@ -3,7 +3,7 @@
 class SysConfig
 {
 
-	public static function getAll()
+	public static function getAll(): array
 	{
 		$res = Database::simpleQuery("SELECT c.configid, c.title, c.filepath, c.status, Group_Concat(cl.locationid) AS locs FROM configtgz c"
 			. " LEFT JOIN configtgz_location cl USING (configid) GROUP BY c.configid");
diff --git a/modules-available/sysconfig/install.inc.php b/modules-available/sysconfig/install.inc.php
index 9d32137c..53882882 100644
--- a/modules-available/sysconfig/install.inc.php
+++ b/modules-available/sysconfig/install.inc.php
@@ -125,28 +125,28 @@ Module::isAvailable('sysconfig');
 $list = ConfigModule::getAll();
 $parentTask = null;
 $configList = [];
-if ($list === false) {
+if ($list === null) {
 	EventLog::warning('Could not regenerate configs - please do so manually');
 } else {
-	foreach ($list as $ad) {
-		if ($ad->moduleType() === 'SshConfig') {
+	foreach ($list as $confMod) {
+		if ($confMod->moduleType() === 'SshConfig') {
 			// 2020-11-12: Split SshConfig into SshConfig and SshKey
-			$pubkey = $ad->getData('publicKey');
+			$pubkey = $confMod->getData('publicKey');
 			if (!empty($pubkey)) {
-				error_log('Legacy module with pubkey ' . $ad->id());
-				$key = ConfigModule::getInstance('SshKey');
-				if ($key !== false) {
+				error_log('Legacy module with pubkey ' . $confMod->id());
+				$key = ConfigModule::getInstanceOrNull('SshKey');
+				if ($key !== null) {
 					$key->setData('publicKey', $pubkey);
-					if ($key->insert($ad->title())) {
+					if ($key->insert($confMod->title())) {
 						// Insert worked, remove key from old module, add this module to the same configs
 						$task = $key->generate(false, $parentTask);
 						if ($task !== false) {
 							$parentTask = $task;
 						}
 						error_log('Inserted new module with id ' . $key->id());
-						$ad->setData('publicKey', false);
-						$ad->update();
-						$configs = ConfigTgz::getAllForModule($ad->id());
+						$confMod->setData('publicKey', false);
+						$confMod->update();
+						$configs = ConfigTgz::getAllForModule($confMod->id());
 						foreach ($configs as $config) {
 							// Add newly created key-only module to all configs
 							$new = array_merge($config->getModuleIds(), [$key->id()]);
@@ -158,9 +158,9 @@ if ($list === false) {
 				}
 			}
 		}
-		if ($ad->needRebuild()) {
+		if ($confMod->needRebuild()) {
 			$update[] = UPDATE_DONE;
-			$task = $ad->generate(false, $parentTask);
+			$task = $confMod->generate(false, $parentTask);
 			if ($task !== false) {
 				$parentTask = $task;
 			}
diff --git a/modules-available/sysconfig/page.inc.php b/modules-available/sysconfig/page.inc.php
index e868ec67..41c4a2db 100644
--- a/modules-available/sysconfig/page.inc.php
+++ b/modules-available/sysconfig/page.inc.php
@@ -152,11 +152,12 @@ class Page_SysConfig extends Page
 			$listid = Request::post('list', Request::REQUIRED, 'int');
 			$this->listConfigContents($listid);
 			return;
+		default:
 		}
 		Message::addError('invalid-action', $action, 'main');
 	}
 
-	private function getLocationNames($locations, $ids)
+	private function getLocationNames(array $locations, array $ids): string
 	{
 		$ret = array();
 		foreach ($ids as $id) {
@@ -236,7 +237,7 @@ class Page_SysConfig extends Page
 	private function listModules()
 	{
 		// Config modules
-		$modules = ConfigModule::getAll();
+		$modules = ConfigModule::getAll() ?? [];
 		$types = array_map(function ($mod) { return $mod->moduleType(); }, $modules);
 		$titles = array_map(function ($mod) { return $mod->title(); }, $modules);
 		array_multisort($types, SORT_ASC, $titles, SORT_ASC, $modules);
@@ -336,7 +337,7 @@ class Page_SysConfig extends Page
 	{
 		$configid = Request::post('rebuild', Request::REQUIRED, 'int');
 		$config = ConfigTgz::get($configid);
-		if ($config === false) {
+		if ($config === null) {
 			Message::addError('config-invalid', $configid);
 			Util::redirect('?do=sysconfig&locationid=' . $this->currentLoc);
 		}
@@ -377,7 +378,7 @@ class Page_SysConfig extends Page
 		// Rebuild depending config.tgz
 		foreach ($existing as $crow) {
 			$config = ConfigTgz::get($crow['configid']);
-			if ($config !== false) {
+			if ($config !== null) {
 				$config->generate();
 			}
 		}
@@ -401,7 +402,7 @@ class Page_SysConfig extends Page
 	{
 		$moduleid = Request::post('rebuild', Request::REQUIRED);
 		$module = ConfigModule::get($moduleid);
-		if ($module === false) {
+		if ($module === null) {
 			Message::addError('config-invalid', $moduleid);
 			Util::redirect('?do=sysconfig');
 		}
@@ -419,7 +420,7 @@ class Page_SysConfig extends Page
 	{
 		$configid = Request::post('del', Request::REQUIRED);
 		$config = ConfigTgz::get($configid);
-		if ($config === false) {
+		if ($config === null) {
 			Message::addError('config-invalid', $configid);
 			Util::redirect('?do=sysconfig&locationid=' . $this->currentLoc);
 		}