diff --git a/blockbot/blockbot.php b/blockbot/blockbot.php
index 3c5e33195..0ff372c50 100644
--- a/blockbot/blockbot.php
+++ b/blockbot/blockbot.php
@@ -15,6 +15,7 @@ use Friendica\DI;
 use Jaybizzle\CrawlerDetect\CrawlerDetect;
 use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
+use Friendica\Network\HTTPException\ForbiddenException;
 
 require_once __DIR__ . DIRECTORY_SEPARATOR . 'vendor' . DIRECTORY_SEPARATOR . 'autoload.php';
 
@@ -92,7 +93,7 @@ function blockbot_init_1(App $a) {
 
 	foreach ($agents as $agent) {
 		if (stristr($_SERVER['HTTP_USER_AGENT'], $agent)) {
-			System::httpExit(403, 'Bots are not allowed');
+			throw new ForbiddenException('Bots are not allowed');
 		}
 	}
 
@@ -130,5 +131,5 @@ function blockbot_init_1(App $a) {
 	}
 
 	logger::info('Blocked bot', $logdata);
-	System::httpExit(403, 'Bots are not allowed');
+	throw new ForbiddenException('Bots are not allowed');
 }
diff --git a/cookienotice/cookienotice.php b/cookienotice/cookienotice.php
index 4ca862800..bec981844 100644
--- a/cookienotice/cookienotice.php
+++ b/cookienotice/cookienotice.php
@@ -35,7 +35,7 @@ function cookienotice_install()
  */
 function cookienotice_addon_admin(App $a, &$s)
 {
-	if (!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
@@ -63,7 +63,7 @@ function cookienotice_addon_admin(App $a, &$s)
  */
 function cookienotice_addon_admin_post(App $a)
 {
-	if (!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
diff --git a/curweather/curweather.php b/curweather/curweather.php
index 0fd60eac2..118c4a9a5 100644
--- a/curweather/curweather.php
+++ b/curweather/curweather.php
@@ -204,7 +204,7 @@ function curweather_addon_settings(App $a, &$s)
 // for accessing the API of openweathermap
 function curweather_addon_admin_post(App $a)
 {
-	if (!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
@@ -216,7 +216,7 @@ function curweather_addon_admin_post(App $a)
 
 function curweather_addon_admin(App $a, &$o)
 {
-	if (!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
diff --git a/diaspora/Diaspora_Connection.php b/diaspora/Diaspora_Connection.php
index a33bf6089..d8390d707 100644
--- a/diaspora/Diaspora_Connection.php
+++ b/diaspora/Diaspora_Connection.php
@@ -1,4 +1,7 @@
 <?php
+
+use Friendica\Core\System;
+
 /**
  * Super-skeletal class to interact with Diaspora.
  *
@@ -29,7 +32,7 @@ class Diaspora_Connection {
 			$this->setPassword($password);
 		}
 
-		$this->cookiejar = tempnam(get_temppath(), 'cookies');
+		$this->cookiejar = tempnam(System::getTempPath(), 'cookies');
 		return $this;
 	}
 
diff --git a/diaspora/diasphp.php b/diaspora/diasphp.php
index f48933a62..4225353e6 100644
--- a/diaspora/diasphp.php
+++ b/diaspora/diasphp.php
@@ -1,4 +1,7 @@
 <?php
+
+use Friendica\Core\System;
+
 /**
  * Ein fies zusammengehackter PHP-Diaspory-Client, der direkt von diesem abgeschaut ist:
  * https://github.com/Javafant/diaspy/blob/master/client.py
@@ -11,7 +14,7 @@ class Diasphp {
 		$this->token_regex = '/content="(.*?)" name="csrf-token/';
 
 		$this->pod = $pod;
-		$this->cookiejar = tempnam(get_temppath(), 'cookies');
+		$this->cookiejar = tempnam(System::getTempPath(), 'cookies');
 	}
 
 	function __destruct() {
diff --git a/irc/irc.php b/irc/irc.php
index 4cb99c3f6..b441cebf3 100644
--- a/irc/irc.php
+++ b/irc/irc.php
@@ -118,7 +118,7 @@ return $o;
 }
 
 function irc_addon_admin_post (&$a) {
-	if(! is_site_admin())
+	if(!$a->isSiteAdmin())
 		return;
 
 	if($_POST['irc-submit']) {
diff --git a/mailstream/mailstream.php b/mailstream/mailstream.php
index 9739913d2..7e3f87f8c 100644
--- a/mailstream/mailstream.php
+++ b/mailstream/mailstream.php
@@ -10,6 +10,7 @@ use Friendica\Content\Text\BBCode;
 use Friendica\Core\Hook;
 use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
+use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\DI;
@@ -204,7 +205,7 @@ function mailstream_do_images(&$item, &$attachments)
 		if (!$components) {
 			continue;
 		}
-		$cookiejar = tempnam(get_temppath(), 'cookiejar-mailstream-');
+		$cookiejar = tempnam(System::getTempPath(), 'cookiejar-mailstream-');
 		$curlResult = DI::httpClient()->fetchFull($url, 0, '', $cookiejar);
 		$attachments[$url] = [
 			'data' => $curlResult->getBody(),
diff --git a/mailstream/phpmailer/class.phpmailer.php b/mailstream/phpmailer/class.phpmailer.php
index 46ff4360c..ab7fe0305 100644
--- a/mailstream/phpmailer/class.phpmailer.php
+++ b/mailstream/phpmailer/class.phpmailer.php
@@ -17,6 +17,8 @@
  * FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+use Friendica\Core\System;
+
 /**
  * PHPMailer - PHP email creation and transport class.
  * @package PHPMailer
@@ -2350,11 +2352,11 @@ class PHPMailer
                     throw new phpmailerException($this->lang('extension_missing') . 'openssl');
                 }
                 // @TODO would be nice to use php://temp streams here, but need to wrap for PHP < 5.1
-                $file = tempnam(get_temppath(), 'mail');
+                $file = tempnam(System::getTempPath(), 'mail');
                 if (false === file_put_contents($file, $body)) {
                     throw new phpmailerException($this->lang('signing') . ' Could not write temp file');
                 }
-                $signed = tempnam(get_temppath(), 'signed');
+                $signed = tempnam(System::getTempPath(), 'signed');
                 //Workaround for PHP bug https://bugs.php.net/bug.php?id=69197
                 if (empty($this->sign_extracerts_file)) {
                     $sign = @openssl_pkcs7_sign(
diff --git a/notifyall/notifyall.php b/notifyall/notifyall.php
index e5e94c7ec..8eff50931 100644
--- a/notifyall/notifyall.php
+++ b/notifyall/notifyall.php
@@ -25,7 +25,7 @@ function notifyall_addon_admin(App $a, &$o)
 
 function notifyall_post(App $a)
 {
-	if(!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
@@ -62,7 +62,7 @@ function notifyall_post(App $a)
 
 function notifyall_content(&$a)
 {
-	if (! is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return '';
 	}
 
diff --git a/pageheader/pageheader.php b/pageheader/pageheader.php
index f0d75400e..ce3b26844 100644
--- a/pageheader/pageheader.php
+++ b/pageheader/pageheader.php
@@ -19,7 +19,7 @@ function pageheader_install() {
 
 function pageheader_addon_admin(App &$a, &$s)
 {
-	if(! is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
@@ -43,7 +43,7 @@ function pageheader_addon_admin(App &$a, &$s)
 
 function pageheader_addon_admin_post(App $a)
 {
-	if(!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}
 
diff --git a/rendertime/rendertime.php b/rendertime/rendertime.php
index 1d8e97019..135bcc76f 100644
--- a/rendertime/rendertime.php
+++ b/rendertime/rendertime.php
@@ -31,7 +31,7 @@ function rendertime_page_end(Friendica\App $a, &$o)
 	$ignored_modules = ["fbrowser"];
 	$ignored = in_array(DI::module()->getName(), $ignored_modules);
 
-	if (is_site_admin() && (($_GET['mode'] ?? '') != 'minimal') && !DI::mode()->isMobile() && !DI::mode()->isMobile() && !$ignored) {
+	if ($a->isSiteAdmin() && (($_GET['mode'] ?? '') != 'minimal') && !DI::mode()->isMobile() && !DI::mode()->isMobile() && !$ignored) {
 
 		$o = $o . '<div class="renderinfo">' . DI::l10n()->t("Database: %s/%s, Network: %s, Rendering: %s, Session: %s, I/O: %s, Other: %s, Total: %s",
 				round($profiler->get('database') - $profiler->get('database_write'), 3),
diff --git a/statusnet/library/codebirdsn.php b/statusnet/library/codebirdsn.php
index cba5f9360..e5e281b9a 100644
--- a/statusnet/library/codebirdsn.php
+++ b/statusnet/library/codebirdsn.php
@@ -2,6 +2,8 @@
 
 namespace CodebirdSN;
 
+use Friendica\Core\System;
+
 /**
  * A Twitter library in PHP.
  *
@@ -820,7 +822,7 @@ class CodebirdSN
                 }
 
 		// To-Do
-		$tempfile = tempnam(get_temppath(), "mimecheck");
+		$tempfile = tempnam(System::getTempPath(), "mimecheck");
 		file_put_contents($tempfile, $data);
 		$mime = image_type_to_mime_type(exif_imagetype($tempfile));
 		unlink($tempfile);
diff --git a/statusnet/statusnet.php b/statusnet/statusnet.php
index e474264ec..75e441515 100644
--- a/statusnet/statusnet.php
+++ b/statusnet/statusnet.php
@@ -47,6 +47,7 @@ use Friendica\Core\Hook;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
 use Friendica\Core\Renderer;
+use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\Contact;
@@ -599,7 +600,7 @@ function statusnet_post_hook(App $a, &$b)
 
 		if ($image != "") {
 			$img_str = DI::httpClient()->fetch($image);
-			$tempfile = tempnam(get_temppath(), "cache");
+			$tempfile = tempnam(System::getTempPath(), "cache");
 			file_put_contents($tempfile, $img_str);
 			$postdata = ["status" => $msg, "media[]" => $tempfile];
 		} else {
@@ -1417,7 +1418,7 @@ function statusnet_convertmsg(App $a, $body)
 			} else {
 				$img_str = DI::httpClient()->fetch($expanded_url, 4);
 
-				$tempfile = tempnam(get_temppath(), "cache");
+				$tempfile = tempnam(System::getTempPath(), "cache");
 				file_put_contents($tempfile, $img_str);
 				$mime = mime_content_type($tempfile);
 				unlink($tempfile);
diff --git a/twitter/twitter.php b/twitter/twitter.php
index ef64e1a2d..6f53b2e4f 100644
--- a/twitter/twitter.php
+++ b/twitter/twitter.php
@@ -85,6 +85,7 @@ use Friendica\Model\Tag;
 use Friendica\Model\User;
 use Friendica\Protocol\Activity;
 use Friendica\Core\Config\Util\ConfigFileLoader;
+use Friendica\Core\System;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Images;
 use Friendica\Util\Strings;
@@ -734,7 +735,7 @@ function twitter_post_hook(App $a, array &$b)
 
 					$img_str = DI::httpClient()->fetch($image['url']);
 
-					$tempfile = tempnam(get_temppath(), 'cache');
+					$tempfile = tempnam(System::getTempPath(), 'cache');
 					file_put_contents($tempfile, $img_str);
 
 					Logger::info('Uploading', ['id' => $b['id'], 'image' => $image['url']]);
diff --git a/windowsphonepush/windowsphonepush.php b/windowsphonepush/windowsphonepush.php
index 6ee4e0f02..4201db661 100644
--- a/windowsphonepush/windowsphonepush.php
+++ b/windowsphonepush/windowsphonepush.php
@@ -36,6 +36,7 @@ use Friendica\DI;
 use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Model\User;
+use Friendica\Network\HTTPException\UnauthorizedException;
 
 function windowsphonepush_install()
 {
@@ -436,8 +437,7 @@ function windowsphonepush_login(App $a)
 	if (!isset($_SERVER['PHP_AUTH_USER'])) {
 		Logger::info('API_login: ' . print_r($_SERVER, true));
 		header('WWW-Authenticate: Basic realm="Friendica"');
-		header('HTTP/1.0 401 Unauthorized');
-		die('This api requires login');
+		throw new UnauthorizedException('This api requires login');
 	}
 
 	$user_id = User::authenticate($_SERVER['PHP_AUTH_USER'], trim($_SERVER['PHP_AUTH_PW']));
@@ -447,8 +447,7 @@ function windowsphonepush_login(App $a)
 	} else {
 		Logger::info('API_login failure: ' . print_r($_SERVER, true));
 		header('WWW-Authenticate: Basic realm="Friendica"');
-		header('HTTP/1.0 401 Unauthorized');
-		die('This api requires login');
+		throw new UnauthorizedException('This api requires login');
 	}
 
 	DI::auth()->setForUser($a, $record);