remove a lot of stuff from global context (functions.php), add a few helper classes instead

14 files changed, 1306 insertions, 45 deletions

diff --git a/classes/api.php b/classes/api.php
index 7b0c58a98..ce046e66a 100755
--- a/classes/api.php
+++ b/classes/api.php
@@ -74,10 +74,10 @@ class API extends Handler {
 		}
 
 		if (get_pref("ENABLE_API_ACCESS", $uid)) {
-			if (authenticate_user($login, $password, false,  Auth_Base::AUTH_SERVICE_API)) {               // try login with normal password
+			if (UserHelper::authenticate($login, $password, false,  Auth_Base::AUTH_SERVICE_API)) {               // try login with normal password
 				$this->wrap(self::STATUS_OK, array("session_id" => session_id(),
 					"api_level" => self::API_LEVEL));
-			} else if (authenticate_user($login, $password_base64, false, Auth_Base::AUTH_SERVICE_API)) { // else try with base64_decoded password
+			} else if (UserHelper::authenticate($login, $password_base64, false, Auth_Base::AUTH_SERVICE_API)) { // else try with base64_decoded password
 				$this->wrap(self::STATUS_OK,	array("session_id" => session_id(),
 					"api_level" => self::API_LEVEL));
 			} else {                                                         // else we are not logged in
@@ -91,7 +91,7 @@ class API extends Handler {
 	}
 
 	function logout() {
-		logout_user();
+		Pref_Users::logout_user();
 		$this->wrap(self::STATUS_OK, array("status" => "OK"));
 	}
 
@@ -343,7 +343,7 @@ class API extends Handler {
 				);
 
 				if ($sanitize_content) {
-					$article["content"] = sanitize(
+					$article["content"] = Sanitizer::sanitize(
 						$line["content"],
 						API::param_to_bool($line['hide_images']),
 						false, $line["site_url"], false, $line["id"]);
@@ -748,7 +748,7 @@ class API extends Handler {
 					if ($show_content) {
 
 						if ($sanitize_content) {
-							$headline_row["content"] = sanitize(
+							$headline_row["content"] = Sanitizer::sanitize(
 								$line["content"],
 								API::param_to_bool($line['hide_images']),
 								false, $line["site_url"], false, $line["id"]);
diff --git a/classes/backend.php b/classes/backend.php
index 27abfbf5f..16c20660a 100644
--- a/classes/backend.php
+++ b/classes/backend.php
@@ -19,8 +19,8 @@ class Backend extends Handler_Protected {
 		$topic = basename(clean($_REQUEST["topic"])); // only one for now
 
 		if ($topic == "main") {
-			$info = get_hotkeys_info();
-			$imap = get_hotkeys_map();
+			$info = RPC::get_hotkeys_info();
+			$imap = RPC::get_hotkeys_map();
 			$omap = array();
 
 			foreach ($imap[1] as $sequence => $action) {
diff --git a/classes/db.php b/classes/db.php
index ac493f6d6..70b97d0ee 100755
--- a/classes/db.php
+++ b/classes/db.php
@@ -113,4 +113,13 @@ class Db
 
 		return self::$instance->pdo;
 	}
+
+	public static function sql_random_function() {
+		if (DB_TYPE == "mysql") {
+			return "RAND()";
+		} else {
+			return "RANDOM()";
+		}
+	}
+
 }
diff --git a/classes/diskcache.php b/classes/diskcache.php
index da7722bf0..24e45ea8b 100644
--- a/classes/diskcache.php
+++ b/classes/diskcache.php
@@ -269,7 +269,7 @@ class DiskCache {
 
 		header("Content-Disposition: inline; filename=\"${filename}${fake_extension}\"");
 
-		return send_local_file($this->getFullPath($filename));
+		return $this->send_local_file($this->getFullPath($filename));
 	}
 
 	public function getUrl($filename) {
@@ -359,4 +359,56 @@ class DiskCache {
 			}
 		}
 	}
+
+	/*	this is essentially a wrapper for readfile() which allows plugins to hook
+		output with httpd-specific "fast" implementation i.e. X-Sendfile or whatever else
+
+		hook function should return true if request was handled (or at least attempted to)
+
+		note that this can be called without user context so the plugin to handle this
+		should be loaded systemwide in config.php */
+	function send_local_file($filename) {
+		if (file_exists($filename)) {
+
+			if (is_writable($filename)) touch($filename);
+
+			$mimetype = mime_content_type($filename);
+
+			// this is hardly ideal but 1) only media is cached in images/ and 2) seemingly only mp4
+			// video files are detected as octet-stream by mime_content_type()
+
+			if ($mimetype == "application/octet-stream")
+				$mimetype = "video/mp4";
+
+			# block SVG because of possible embedded javascript (.....)
+			$mimetype_blacklist = [ "image/svg+xml" ];
+
+			/* only serve video and images */
+			if (!preg_match("/(image|video)\//", $mimetype) || in_array($mimetype, $mimetype_blacklist)) {
+				http_response_code(400);
+				header("Content-type: text/plain");
+
+				print "Stored file has disallowed content type ($mimetype)";
+				return false;
+			}
+
+			$tmppluginhost = new PluginHost();
+
+			$tmppluginhost->load(PLUGINS, PluginHost::KIND_SYSTEM);
+			$tmppluginhost->load_data();
+
+			foreach ($tmppluginhost->get_hooks(PluginHost::HOOK_SEND_LOCAL_FILE) as $plugin) {
+				if ($plugin->hook_send_local_file($filename)) return true;
+			}
+
+			header("Content-type: $mimetype");
+
+			$stamp = gmdate("D, d M Y H:i:s", filemtime($filename)) . " GMT";
+			header("Last-Modified: $stamp", true);
+
+			return readfile($filename);
+		} else {
+			return false;
+		}
+	}
 }
diff --git a/classes/feeds.php b/classes/feeds.php
index 4714e4c9a..b428252d8 100755
--- a/classes/feeds.php
+++ b/classes/feeds.php
@@ -305,7 +305,7 @@ class Feeds extends Handler_Protected {
                     $line["buttons"] .= $p->hook_article_button($line);
                 }
 
-                $line["content"] = sanitize($line["content"],
+                $line["content"] = Sanitizer::sanitize($line["content"],
                     $line['hide_images'], false, $line["site_url"], $highlight_words, $line["id"]);
 
                 foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_RENDER_ARTICLE_CDM) as $p) {
@@ -550,7 +550,7 @@ class Feeds extends Handler_Protected {
             						"disable_cache" => (bool) $disable_cache];
 
 		// this is parsed by handleRpcJson() on first viewfeed() to set cdm expanded, etc
-		$reply['runtime-info'] = make_runtime_info();
+		$reply['runtime-info'] = RPC::make_runtime_info();
 
 		$reply_json = json_encode($reply);
 
@@ -1124,11 +1124,11 @@ class Feeds extends Handler_Protected {
 
 		$pdo = Db::pdo();
 
-		$url = validate_url($url);
+		$url = UrlHelper::validate($url);
 
 		if (!$url) return array("code" => 2);
 
-		$contents = @fetch_file_contents($url, false, $auth_login, $auth_pass);
+		$contents = @UrlHelper::fetch($url, false, $auth_login, $auth_pass);
 
 		foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_SUBSCRIBE_FEED) as $plugin) {
 			$contents = $plugin->hook_subscribe_feed($contents, $url, $auth_login, $auth_pass);
@@ -1924,7 +1924,7 @@ class Feeds extends Handler_Protected {
 	}
 
 	static function get_feeds_from_html($url, $content) {
-		$url     = validate_url($url);
+		$url     = UrlHelper::validate($url);
 		$baseUrl = substr($url, 0, strrpos($url, '/') + 1);
 
 		$feedUrls = [];
diff --git a/classes/handler/public.php b/classes/handler/public.php
index 822ad1fd9..9671b18b2 100755
--- a/classes/handler/public.php
+++ b/classes/handler/public.php
@@ -81,7 +81,7 @@ class Handler_Public extends Handler {
 			$tpl->setVariable('SELF_URL', htmlspecialchars(get_self_url_prefix()), true);
 			while ($line = $result->fetch()) {
 
-				$line["content_preview"] = sanitize(truncate_string(strip_tags($line["content"]), 100, '...'));
+				$line["content_preview"] = Sanitizer::sanitize(truncate_string(strip_tags($line["content"]), 100, '...'));
 
 				foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_QUERY_HEADLINES) as $p) {
 					$line = $p->hook_query_headlines($line);
@@ -98,7 +98,7 @@ class Handler_Public extends Handler {
 				$tpl->setVariable('ARTICLE_TITLE', htmlspecialchars($line['title']), true);
 				$tpl->setVariable('ARTICLE_EXCERPT', $line["content_preview"], true);
 
-				$content = sanitize($line["content"], false, $owner_uid,
+				$content = Sanitizer::sanitize($line["content"], false, $owner_uid,
 					$feed_site_url, false, $line["id"]);
 
 				$content = DiskCache::rewriteUrls($content);
@@ -180,7 +180,7 @@ class Handler_Public extends Handler {
 
 			while ($line = $result->fetch()) {
 
-				$line["content_preview"] = sanitize(truncate_string(strip_tags($line["content_preview"]), 100, '...'));
+				$line["content_preview"] = Sanitizer::sanitize(truncate_string(strip_tags($line["content_preview"]), 100, '...'));
 
 				foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_QUERY_HEADLINES) as $p) {
 					$line = $p->hook_query_headlines($line, 100);
@@ -196,7 +196,7 @@ class Handler_Public extends Handler {
 				$article['link']	= $line['link'];
 				$article['title'] = $line['title'];
 				$article['excerpt'] = $line["content_preview"];
-				$article['content'] = sanitize($line["content"], false, $owner_uid, $feed_site_url, false, $line["id"]);
+				$article['content'] = Sanitizer::sanitize($line["content"], false, $owner_uid, $feed_site_url, false, $line["id"]);
 				$article['updated'] = date('c', strtotime($line["updated"]));
 
 				if ($line['note']) $article['note'] = $line['note'];
@@ -284,7 +284,7 @@ class Handler_Public extends Handler {
 
 	function logout() {
 		if (validate_csrf($_POST["csrf_token"])) {
-			logout_user();
+			Pref_Users::logout_user();
 			header("Location: index.php");
 		} else {
 			header("Content-Type: text/json");
@@ -343,7 +343,7 @@ class Handler_Public extends Handler {
 			$line["tags"] = Article::get_article_tags($id, $owner_uid, $line["tag_cache"]);
 			unset($line["tag_cache"]);
 
-			$line["content"] = sanitize($line["content"],
+			$line["content"] = Sanitizer::sanitize($line["content"],
 				$line['hide_images'],
 				$owner_uid, $line["site_url"], false, $line["id"]);
 
@@ -470,7 +470,7 @@ class Handler_Public extends Handler {
 		if (!$format) $format = 'atom';
 
 		if (SINGLE_USER_MODE) {
-			authenticate_user("admin", null);
+			UserHelper::authenticate("admin", null);
 		}
 
 		$owner_id = false;
@@ -508,7 +508,7 @@ class Handler_Public extends Handler {
 
 	function sharepopup() {
 		if (SINGLE_USER_MODE) {
-			login_sequence();
+			UserHelper::login_sequence();
 		}
 
 		header('Content-Type: text/html; charset=utf-8');
@@ -681,7 +681,7 @@ class Handler_Public extends Handler {
 				@session_set_cookie_params(0);
 			}
 
-			if (authenticate_user($login, $password)) {
+			if (UserHelper::authenticate($login, $password)) {
 				$_POST["password"] = "";
 
 				if (get_schema_version() >= 120) {
@@ -729,7 +729,7 @@ class Handler_Public extends Handler {
 
 	function subscribe() {
 		if (SINGLE_USER_MODE) {
-			login_sequence();
+			UserHelper::login_sequence();
 		}
 
 		if ($_SESSION["uid"]) {
@@ -878,7 +878,7 @@ class Handler_Public extends Handler {
 			print "</div></div></body></html>";
 
 		} else {
-			render_login_form();
+			$this->render_login_form();
 		}
 	}
 
@@ -1092,7 +1092,7 @@ class Handler_Public extends Handler {
 
 		if (!SINGLE_USER_MODE && $_SESSION["access_level"] < 10) {
 			$_SESSION["login_error_msg"] = __("Your access level is insufficient to run this script.");
-			render_login_form();
+			$this->render_login_form();
 			exit;
 		}
 
@@ -1272,5 +1272,13 @@ class Handler_Public extends Handler {
 			print error_json(14);
 		}
 	}
+
+	static function render_login_form() {
+		header('Cache-Control: public');
+
+		require_once "login_form.php";
+		exit;
+	}
+
 }
 ?>
diff --git a/classes/pref/feeds.php b/classes/pref/feeds.php
index a6a543b76..4ff6ac9c2 100755
--- a/classes/pref/feeds.php
+++ b/classes/pref/feeds.php
@@ -1703,7 +1703,7 @@ class Pref_Feeds extends Handler_Protected {
 		foreach ($feeds as $feed) {
 			$feed = trim($feed);
 
-			if (validate_url($feed)) {
+			if (UrlHelper::validate($feed)) {
 
 				$this->pdo->beginTransaction();
 
diff --git a/classes/pref/prefs.php b/classes/pref/prefs.php
index ac2684683..f825454dd 100644
--- a/classes/pref/prefs.php
+++ b/classes/pref/prefs.php
@@ -257,7 +257,7 @@ class Pref_Prefs extends Handler_Protected {
 				AND owner_uid = :uid");
 		$sth->execute([":profile" => $_SESSION['profile'], ":uid" => $_SESSION['uid']]);
 
-		initialize_user_prefs($_SESSION["uid"], $_SESSION["profile"]);
+		$this->initialize_user_prefs($_SESSION["uid"], $_SESSION["profile"]);
 
 		echo __("Your preferences are now set to default values.");
 	}
@@ -590,9 +590,9 @@ class Pref_Prefs extends Handler_Protected {
 		if ($profile) {
 			print_notice(__("Some preferences are only available in default profile."));
 
-			initialize_user_prefs($_SESSION["uid"], $profile);
+			$this->initialize_user_prefs($_SESSION["uid"], $profile);
 		} else {
-			initialize_user_prefs($_SESSION["uid"]);
+			$this->initialize_user_prefs($_SESSION["uid"]);
 		}
 
 		$prefs_available = [];
@@ -1366,4 +1366,57 @@ class Pref_Prefs extends Handler_Protected {
 
 		$this->appPasswordList();
 	}
+
+	static function initialize_user_prefs($uid, $profile = false) {
+
+		if (get_schema_version() < 63) $profile_qpart = "";
+
+		$pdo = Db::pdo();
+		$in_nested_tr = false;
+
+		try {
+			$pdo->beginTransaction();
+		} catch (Exception $e) {
+			$in_nested_tr = true;
+		}
+
+		$sth = $pdo->query("SELECT pref_name,def_value FROM ttrss_prefs");
+
+		if (!is_numeric($profile) || !$profile || get_schema_version() < 63) $profile = null;
+
+		$u_sth = $pdo->prepare("SELECT pref_name
+			FROM ttrss_user_prefs WHERE owner_uid = :uid AND
+				(profile = :profile OR (:profile IS NULL AND profile IS NULL))");
+		$u_sth->execute([':uid' => $uid, ':profile' => $profile]);
+
+		$active_prefs = array();
+
+		while ($line = $u_sth->fetch()) {
+			array_push($active_prefs, $line["pref_name"]);
+		}
+
+		while ($line = $sth->fetch()) {
+			if (array_search($line["pref_name"], $active_prefs) === false) {
+//				print "adding " . $line["pref_name"] . "<br>";
+
+				if (get_schema_version() < 63) {
+					$i_sth = $pdo->prepare("INSERT INTO ttrss_user_prefs
+						(owner_uid,pref_name,value) VALUES
+						(?, ?, ?)");
+					$i_sth->execute([$uid, $line["pref_name"], $line["def_value"]]);
+
+				} else {
+					$i_sth = $pdo->prepare("INSERT INTO ttrss_user_prefs
+						(owner_uid,pref_name,value, profile) VALUES
+						(?, ?, ?, ?)");
+					$i_sth->execute([$uid, $line["pref_name"], $line["def_value"], $profile]);
+				}
+
+			}
+		}
+
+		if (!$in_nested_tr) $pdo->commit();
+
+	}
+
 }
diff --git a/classes/pref/users.php b/classes/pref/users.php
index 851d4fa9e..aeabc4502 100644
--- a/classes/pref/users.php
+++ b/classes/pref/users.php
@@ -259,7 +259,7 @@ class Pref_Users extends Handler_Protected {
 					print T_sprintf("Added user %s with password %s",
 						$login, $tmp_user_pwd);
 
-					initialize_user($new_uid);
+					$this->initialize_user($new_uid);
 
 				} else {
 
@@ -443,4 +443,25 @@ class Pref_Users extends Handler_Protected {
 				return $default;
 		}
 
+	// this is called after user is created to initialize default feeds, labels
+	// or whatever else
+	// user preferences are checked on every login, not here
+	static function initialize_user($uid) {
+
+		$pdo = Db::pdo();
+
+		$sth = $pdo->prepare("insert into ttrss_feeds (owner_uid,title,feed_url)
+			values (?, 'Tiny Tiny RSS: Forum',
+				'https://tt-rss.org/forum/rss.php')");
+		$sth->execute([$uid]);
+	}
+
+	static function logout_user() {
+		@session_destroy();
+		if (isset($_COOKIE[session_name()])) {
+		   setcookie(session_name(), '', time()-42000, '/');
+		}
+		session_commit();
+	}
+
 }
diff --git a/classes/rpc.php b/classes/rpc.php
index 55651cc27..a7123566c 100755
--- a/classes/rpc.php
+++ b/classes/rpc.php
@@ -52,7 +52,7 @@ class RPC extends Handler_Protected {
 					$profile_id = $row['id'];
 
 					if ($profile_id) {
-						initialize_user_prefs($_SESSION["uid"], $profile_id);
+						Pref_Prefs::initialize_user_prefs($_SESSION["uid"], $profile_id);
 					}
 				}
 			}
@@ -279,7 +279,7 @@ class RPC extends Handler_Protected {
 		];
 
 		if ($seq % 2 == 0)
-			$reply['runtime-info'] = make_runtime_info();
+			$reply['runtime-info'] = $this->make_runtime_info();
 
 		print json_encode($reply);
 	}
@@ -323,8 +323,8 @@ class RPC extends Handler_Protected {
 		$reply['error'] = sanity_check();
 
 		if ($reply['error']['code'] == 0) {
-			$reply['init-params'] = make_init_params();
-			$reply['runtime-info'] = make_runtime_info();
+			$reply['init-params'] = $this->make_init_params();
+			$reply['runtime-info'] = $this->make_runtime_info();
 		}
 
 		print json_encode($reply);
@@ -461,7 +461,7 @@ class RPC extends Handler_Protected {
 			$updstart_thresh_qpart = "AND (ttrss_feeds.last_update_started IS NULL OR ttrss_feeds.last_update_started < DATE_SUB(NOW(), INTERVAL 5 MINUTE))";
 		}
 
-		$random_qpart = sql_random_function();
+		$random_qpart = Db::sql_random_function();
 
 		$pdo = Db::pdo();
 
@@ -602,7 +602,7 @@ class RPC extends Handler_Protected {
 		get_version($git_commit, $git_timestamp);
 
 		if (defined('CHECK_FOR_UPDATES') && CHECK_FOR_UPDATES && $_SESSION["access_level"] >= 10 && $git_timestamp) {
-			$content = @fetch_file_contents(["url" => "https://tt-rss.org/version.json"]);
+			$content = @UrlHelper::fetch(["url" => "https://tt-rss.org/version.json"]);
 
 			if ($content) {
 				$content = json_decode($content, true);
@@ -620,4 +620,292 @@ class RPC extends Handler_Protected {
 		print json_encode($rv);
 	}
 
+	private function make_init_params() {
+		$params = array();
+
+		foreach (array("ON_CATCHUP_SHOW_NEXT_FEED", "HIDE_READ_FEEDS",
+					 "ENABLE_FEED_CATS", "FEEDS_SORT_BY_UNREAD", "CONFIRM_FEED_CATCHUP",
+					 "CDM_AUTO_CATCHUP", "FRESH_ARTICLE_MAX_AGE",
+					 "HIDE_READ_SHOWS_SPECIAL", "COMBINED_DISPLAY_MODE") as $param) {
+
+			$params[strtolower($param)] = (int) get_pref($param);
+		}
+
+		$params["check_for_updates"] = CHECK_FOR_UPDATES;
+		$params["icons_url"] = ICONS_URL;
+		$params["cookie_lifetime"] = SESSION_COOKIE_LIFETIME;
+		$params["default_view_mode"] = get_pref("_DEFAULT_VIEW_MODE");
+		$params["default_view_limit"] = (int) get_pref("_DEFAULT_VIEW_LIMIT");
+		$params["default_view_order_by"] = get_pref("_DEFAULT_VIEW_ORDER_BY");
+		$params["bw_limit"] = (int) $_SESSION["bw_limit"];
+		$params["is_default_pw"] = Pref_Prefs::isdefaultpassword();
+		$params["label_base_index"] = (int) LABEL_BASE_INDEX;
+
+		$theme = get_pref( "USER_CSS_THEME", false, false);
+		$params["theme"] = theme_exists($theme) ? $theme : "";
+
+		$params["plugins"] = implode(", ", PluginHost::getInstance()->get_plugin_names());
+
+		$params["php_platform"] = PHP_OS;
+		$params["php_version"] = PHP_VERSION;
+
+		$params["sanity_checksum"] = sha1(file_get_contents("include/sanity_check.php"));
+
+		$pdo = Db::pdo();
+
+		$sth = $pdo->prepare("SELECT MAX(id) AS mid, COUNT(*) AS nf FROM
+				ttrss_feeds WHERE owner_uid = ?");
+		$sth->execute([$_SESSION['uid']]);
+		$row = $sth->fetch();
+
+		$max_feed_id = $row["mid"];
+		$num_feeds = $row["nf"];
+
+		$params["self_url_prefix"] = get_self_url_prefix();
+		$params["max_feed_id"] = (int) $max_feed_id;
+		$params["num_feeds"] = (int) $num_feeds;
+
+		$params["hotkeys"] = $this->get_hotkeys_map();
+
+		$params["widescreen"] = (int) $_COOKIE["ttrss_widescreen"];
+
+		$params['simple_update'] = defined('SIMPLE_UPDATE_MODE') && SIMPLE_UPDATE_MODE;
+
+		$params["icon_indicator_white"] = $this->image_to_base64("images/indicator_white.gif");
+
+		$params["labels"] = Labels::get_all_labels($_SESSION["uid"]);
+
+		return $params;
+	}
+
+	private function image_to_base64($filename) {
+		if (file_exists($filename)) {
+			$ext = pathinfo($filename, PATHINFO_EXTENSION);
+
+			return "data:image/$ext;base64," . base64_encode(file_get_contents($filename));
+		} else {
+			return "";
+		}
+	}
+
+	static function make_runtime_info() {
+		$data = array();
+
+		$pdo = Db::pdo();
+
+		$sth = $pdo->prepare("SELECT MAX(id) AS mid, COUNT(*) AS nf FROM
+				ttrss_feeds WHERE owner_uid = ?");
+		$sth->execute([$_SESSION['uid']]);
+		$row = $sth->fetch();
+
+		$max_feed_id = $row['mid'];
+		$num_feeds = $row['nf'];
+
+		$data["max_feed_id"] = (int) $max_feed_id;
+		$data["num_feeds"] = (int) $num_feeds;
+		$data['cdm_expanded'] = get_pref('CDM_EXPANDED');
+		$data["labels"] = Labels::get_all_labels($_SESSION["uid"]);
+
+		if (LOG_DESTINATION == 'sql' && $_SESSION['access_level'] >= 10) {
+			if (DB_TYPE == 'pgsql') {
+				$log_interval = "created_at > NOW() - interval '1 hour'";
+			} else {
+				$log_interval = "created_at > DATE_SUB(NOW(), INTERVAL 1 HOUR)";
+			}
+
+			$sth = $pdo->prepare("SELECT COUNT(id) AS cid FROM ttrss_error_log WHERE $log_interval");
+			$sth->execute();
+
+			if ($row = $sth->fetch()) {
+				$data['recent_log_events'] = $row['cid'];
+			}
+		}
+
+		if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock")) {
+
+			$data['daemon_is_running'] = (int) file_is_locked("update_daemon.lock");
+
+			if (time() - $_SESSION["daemon_stamp_check"] > 30) {
+
+				$stamp = (int) @file_get_contents(LOCK_DIRECTORY . "/update_daemon.stamp");
+
+				if ($stamp) {
+					$stamp_delta = time() - $stamp;
+
+					if ($stamp_delta > 1800) {
+						$stamp_check = 0;
+					} else {
+						$stamp_check = 1;
+						$_SESSION["daemon_stamp_check"] = time();
+					}
+
+					$data['daemon_stamp_ok'] = $stamp_check;
+
+					$stamp_fmt = date("Y.m.d, G:i", $stamp);
+
+					$data['daemon_stamp'] = $stamp_fmt;
+				}
+			}
+		}
+
+		return $data;
+	}
+
+	static function get_hotkeys_info() {
+		$hotkeys = array(
+			__("Navigation") => array(
+				"next_feed" => __("Open next feed"),
+				"prev_feed" => __("Open previous feed"),
+				"next_article_or_scroll" => __("Open next article (in combined mode, scroll down)"),
+				"prev_article_or_scroll" => __("Open previous article (in combined mode, scroll up)"),
+				"next_headlines_page" => __("Scroll headlines by one page down"),
+				"prev_headlines_page" => __("Scroll headlines by one page up"),
+				"next_article_noscroll" => __("Open next article"),
+				"prev_article_noscroll" => __("Open previous article"),
+				"next_article_noexpand" => __("Move to next article (don't expand)"),
+				"prev_article_noexpand" => __("Move to previous article (don't expand)"),
+				"search_dialog" => __("Show search dialog"),
+				"cancel_search" => __("Cancel active search")),
+			__("Article") => array(
+				"toggle_mark" => __("Toggle starred"),
+				"toggle_publ" => __("Toggle published"),
+				"toggle_unread" => __("Toggle unread"),
+				"edit_tags" => __("Edit tags"),
+				"open_in_new_window" => __("Open in new window"),
+				"catchup_below" => __("Mark below as read"),
+				"catchup_above" => __("Mark above as read"),
+				"article_scroll_down" => __("Scroll down"),
+				"article_scroll_up" => __("Scroll up"),
+				"article_page_down" => __("Scroll down page"),
+				"article_page_up" => __("Scroll up page"),
+				"select_article_cursor" => __("Select article under cursor"),
+				"email_article" => __("Email article"),
+				"close_article" => __("Close/collapse article"),
+				"toggle_expand" => __("Toggle article expansion (combined mode)"),
+				"toggle_widescreen" => __("Toggle widescreen mode"),
+				"toggle_full_text" => __("Toggle full article text via Readability")),
+			__("Article selection") => array(
+				"select_all" => __("Select all articles"),
+				"select_unread" => __("Select unread"),
+				"select_marked" => __("Select starred"),
+				"select_published" => __("Select published"),
+				"select_invert" => __("Invert selection"),
+				"select_none" => __("Deselect everything")),
+			__("Feed") => array(
+				"feed_refresh" => __("Refresh current feed"),
+				"feed_unhide_read" => __("Un/hide read feeds"),
+				"feed_subscribe" => __("Subscribe to feed"),
+				"feed_edit" => __("Edit feed"),
+				"feed_catchup" => __("Mark as read"),
+				"feed_reverse" => __("Reverse headlines"),
+				"feed_toggle_vgroup" => __("Toggle headline grouping"),
+				"feed_debug_update" => __("Debug feed update"),
+				"feed_debug_viewfeed" => __("Debug viewfeed()"),
+				"catchup_all" => __("Mark all feeds as read"),
+				"cat_toggle_collapse" => __("Un/collapse current category"),
+				"toggle_cdm_expanded" => __("Toggle auto expand in combined mode"),
+				"toggle_combined_mode" => __("Toggle combined mode")),
+			__("Go to") => array(
+				"goto_all" => __("All articles"),
+				"goto_fresh" => __("Fresh"),
+				"goto_marked" => __("Starred"),
+				"goto_published" => __("Published"),
+				"goto_read" => __("Recently read"),
+				"goto_tagcloud" => __("Tag cloud"),
+				"goto_prefs" => __("Preferences")),
+			__("Other") => array(
+				"create_label" => __("Create label"),
+				"create_filter" => __("Create filter"),
+				"collapse_sidebar" => __("Un/collapse sidebar"),
+				"help_dialog" => __("Show help dialog"))
+		);
+
+		foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_HOTKEY_INFO) as $plugin) {
+			$hotkeys = $plugin->hook_hotkey_info($hotkeys);
+		}
+
+		return $hotkeys;
+	}
+
+	// {3} - 3 panel mode only
+	// {C} - combined mode only
+	static function get_hotkeys_map() {
+		$hotkeys = array(
+			"k" => "next_feed",
+			"j" => "prev_feed",
+			"n" => "next_article_noscroll",
+			"p" => "prev_article_noscroll",
+			"N" => "article_page_down",
+			"P" => "article_page_up",
+			"*(33)|Shift+PgUp" => "article_page_up",
+			"*(34)|Shift+PgDn" => "article_page_down",
+			"{3}(38)|Up" => "prev_article_or_scroll",
+			"{3}(40)|Down" => "next_article_or_scroll",
+			"*(38)|Shift+Up" => "article_scroll_up",
+			"*(40)|Shift+Down" => "article_scroll_down",
+			"^(38)|Ctrl+Up" => "prev_article_noscroll",
+			"^(40)|Ctrl+Down" => "next_article_noscroll",
+			"/" => "search_dialog",
+			"\\" => "cancel_search",
+			"s" => "toggle_mark",
+			"S" => "toggle_publ",
+			"u" => "toggle_unread",
+			"T" => "edit_tags",
+			"o" => "open_in_new_window",
+			"c p" => "catchup_below",
+			"c n" => "catchup_above",
+			"a W" => "toggle_widescreen",
+			"a e" => "toggle_full_text",
+			"e" => "email_article",
+			"a q" => "close_article",
+			"a a" => "select_all",
+			"a u" => "select_unread",
+			"a U" => "select_marked",
+			"a p" => "select_published",
+			"a i" => "select_invert",
+			"a n" => "select_none",
+			"f r" => "feed_refresh",
+			"f a" => "feed_unhide_read",
+			"f s" => "feed_subscribe",
+			"f e" => "feed_edit",
+			"f q" => "feed_catchup",
+			"f x" => "feed_reverse",
+			"f g" => "feed_toggle_vgroup",
+			"f D" => "feed_debug_update",
+			"f G" => "feed_debug_viewfeed",
+			"f C" => "toggle_combined_mode",
+			"f c" => "toggle_cdm_expanded",
+			"Q" => "catchup_all",
+			"x" => "cat_toggle_collapse",
+			"g a" => "goto_all",
+			"g f" => "goto_fresh",
+			"g s" => "goto_marked",
+			"g p" => "goto_published",
+			"g r" => "goto_read",
+			"g t" => "goto_tagcloud",
+			"g P" => "goto_prefs",
+			"r" => "select_article_cursor",
+			"c l" => "create_label",
+			"c f" => "create_filter",
+			"c s" => "collapse_sidebar",
+			"?" => "help_dialog",
+		);
+
+		foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_HOTKEY_MAP) as $plugin) {
+			$hotkeys = $plugin->hook_hotkey_map($hotkeys);
+		}
+
+		$prefixes = array();
+
+		foreach (array_keys($hotkeys) as $hotkey) {
+			$pair = explode(" ", $hotkey, 2);
+
+			if (count($pair) > 1 && !in_array($pair[0], $prefixes)) {
+				array_push($prefixes, $pair[0]);
+			}
+		}
+
+		return array($prefixes, $hotkeys);
+	}
+
 }
diff --git a/classes/rssutils.php b/classes/rssutils.php
index 7cfbca6d3..14a0a18a7 100755
--- a/classes/rssutils.php
+++ b/classes/rssutils.php
@@ -218,7 +218,7 @@ class RSSUtils {
 			}
 
 			if (!$basic_info) {
-				$feed_data = fetch_file_contents($fetch_url, false,
+				$feed_data = UrlHelper::fetch($fetch_url, false,
 					$auth_login, $auth_pass, false,
 					FEED_FETCH_TIMEOUT,
 					0);
@@ -268,8 +268,6 @@ class RSSUtils {
 	 */
 	static function update_rss_feed($feed, $no_cache = false) {
 
-		reset_fetch_domain_quota();
-
 		Debug::log("start", Debug::$LOG_VERBOSE);
 
 		$pdo = Db::pdo();
@@ -400,7 +398,7 @@ class RSSUtils {
 
 			Debug::log("fetching [$fetch_url] (force_refetch: $force_refetch)...", Debug::$LOG_VERBOSE);
 
-			$feed_data = fetch_file_contents([
+			$feed_data = UrlHelper::fetch([
 				"url" => $fetch_url,
 				"login" => $auth_login,
 				"pass" => $auth_pass,
@@ -1225,7 +1223,7 @@ class RSSUtils {
 						global $fetch_last_error_code;
 						global $fetch_last_error;
 
-						$file_content = fetch_file_contents(array("url" => $src,
+						$file_content = UrlHelper::fetch(array("url" => $src,
 							"http_referrer" => $src,
 							"max_size" => MAX_CACHE_FILE_SIZE));
 
@@ -1255,7 +1253,7 @@ class RSSUtils {
 			global $fetch_last_error_code;
 			global $fetch_last_error;
 
-			$file_content = fetch_file_contents(array("url" => $url,
+			$file_content = UrlHelper::fetch(array("url" => $url,
 				"http_referrer" => $url,
 				"max_size" => MAX_CACHE_FILE_SIZE));
 
@@ -1517,7 +1515,7 @@ class RSSUtils {
 	static function housekeeping_user($owner_uid) {
 		$tmph = new PluginHost();
 
-		load_user_plugins($owner_uid, $tmph);
+		UserHelper::load_user_plugins($owner_uid, $tmph);
 
 		$tmph->run_hooks(PluginHost::HOOK_HOUSE_KEEPING, "hook_house_keeping", "");
 	}
@@ -1546,7 +1544,7 @@ class RSSUtils {
 
 			if ($favicon_url) {
 				// Limiting to "image" type misses those served with text/plain
-				$contents = fetch_file_contents($favicon_url); // , "image");
+				$contents = UrlHelper::fetch($favicon_url); // , "image");
 
 				if ($contents) {
 					// Crude image type matching.
@@ -1719,7 +1717,7 @@ class RSSUtils {
 
 		$favicon_url = false;
 
-		if ($html = @fetch_file_contents($url)) {
+		if ($html = @UrlHelper::fetch($url)) {
 
 			$doc = new DOMDocument();
 			if ($doc->loadHTML($html)) {
diff --git a/classes/sanitizer.php b/classes/sanitizer.php
new file mode 100644
index 000000000..8e008ef85
--- /dev/null
+++ b/classes/sanitizer.php
@@ -0,0 +1,217 @@
+<?php
+class Sanitizer {
+	private static function strip_harmful_tags($doc, $allowed_elements, $disallowed_attributes) {
+		$xpath = new DOMXPath($doc);
+		$entries = $xpath->query('//*');
+
+		foreach ($entries as $entry) {
+			if (!in_array($entry->nodeName, $allowed_elements)) {
+				$entry->parentNode->removeChild($entry);
+			}
+
+			if ($entry->hasAttributes()) {
+				$attrs_to_remove = array();
+
+				foreach ($entry->attributes as $attr) {
+
+					if (strpos($attr->nodeName, 'on') === 0) {
+						array_push($attrs_to_remove, $attr);
+					}
+
+					if (strpos($attr->nodeName, "data-") === 0) {
+						array_push($attrs_to_remove, $attr);
+					}
+
+					if ($attr->nodeName == 'href' && stripos($attr->value, 'javascript:') === 0) {
+						array_push($attrs_to_remove, $attr);
+					}
+
+					if (in_array($attr->nodeName, $disallowed_attributes)) {
+						array_push($attrs_to_remove, $attr);
+					}
+				}
+
+				foreach ($attrs_to_remove as $attr) {
+					$entry->removeAttributeNode($attr);
+				}
+			}
+		}
+
+		return $doc;
+	}
+
+	public static function iframe_whitelisted($entry) {
+		@$src = parse_url($entry->getAttribute("src"), PHP_URL_HOST);
+
+		if ($src) {
+			foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_IFRAME_WHITELISTED) as $plugin) {
+				if ($plugin->hook_iframe_whitelisted($src))
+					return true;
+			}
+		}
+
+		return false;
+	}
+
+	public static function sanitize($str, $force_remove_images = false, $owner = false, $site_url = false, $highlight_words = false, $article_id = false) {
+		if (!$owner) $owner = $_SESSION["uid"];
+
+		$res = trim($str); if (!$res) return '';
+
+		$doc = new DOMDocument();
+		$doc->loadHTML('<?xml encoding="UTF-8">' . $res);
+		$xpath = new DOMXPath($doc);
+
+		$rewrite_base_url = $site_url ? $site_url : get_self_url_prefix();
+
+		$entries = $xpath->query('(//a[@href]|//img[@src]|//source[@srcset|@src])');
+
+		foreach ($entries as $entry) {
+
+			if ($entry->hasAttribute('href')) {
+				$entry->setAttribute('href',
+					rewrite_relative_url($rewrite_base_url, $entry->getAttribute('href')));
+
+				$entry->setAttribute('rel', 'noopener noreferrer');
+				$entry->setAttribute("target", "_blank");
+			}
+
+			if ($entry->hasAttribute('src')) {
+				$entry->setAttribute('src',
+					rewrite_relative_url($rewrite_base_url, $entry->getAttribute('src')));
+			}
+
+			if ($entry->nodeName == 'img') {
+				$entry->setAttribute('referrerpolicy', 'no-referrer');
+				$entry->setAttribute('loading', 'lazy');
+			}
+
+			if ($entry->hasAttribute('srcset')) {
+				$matches = RSSUtils::decode_srcset($entry->getAttribute('srcset'));
+
+				for ($i = 0; $i < count($matches); $i++) {
+					$matches[$i]["url"] = rewrite_relative_url($rewrite_base_url, $matches[$i]["url"]);
+				}
+
+				$entry->setAttribute("srcset", RSSUtils::encode_srcset($matches));
+			}
+
+			if ($entry->hasAttribute('src') &&
+					($owner && get_pref("STRIP_IMAGES", $owner)) || $force_remove_images || $_SESSION["bw_limit"]) {
+
+				$p = $doc->createElement('p');
+
+				$a = $doc->createElement('a');
+				$a->setAttribute('href', $entry->getAttribute('src'));
+
+				$a->appendChild(new DOMText($entry->getAttribute('src')));
+				$a->setAttribute('target', '_blank');
+				$a->setAttribute('rel', 'noopener noreferrer');
+
+				$p->appendChild($a);
+
+				if ($entry->nodeName == 'source') {
+
+					if ($entry->parentNode && $entry->parentNode->parentNode)
+						$entry->parentNode->parentNode->replaceChild($p, $entry->parentNode);
+
+				} else if ($entry->nodeName == 'img') {
+					if ($entry->parentNode)
+						$entry->parentNode->replaceChild($p, $entry);
+				}
+			}
+		}
+
+		$entries = $xpath->query('//iframe');
+		foreach ($entries as $entry) {
+			if (!Sanitizer::iframe_whitelisted($entry)) {
+				$entry->setAttribute('sandbox', 'allow-scripts');
+			} else {
+				if (is_prefix_https()) {
+					$entry->setAttribute("src",
+						str_replace("http://", "https://",
+							$entry->getAttribute("src")));
+				}
+			}
+		}
+
+		$allowed_elements = array('a', 'abbr', 'address', 'acronym', 'audio', 'article', 'aside',
+			'b', 'bdi', 'bdo', 'big', 'blockquote', 'body', 'br',
+			'caption', 'cite', 'center', 'code', 'col', 'colgroup',
+			'data', 'dd', 'del', 'details', 'description', 'dfn', 'div', 'dl', 'font',
+			'dt', 'em', 'footer', 'figure', 'figcaption',
+			'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'header', 'hr', 'html', 'i',
+			'img', 'ins', 'kbd', 'li', 'main', 'mark', 'nav', 'noscript',
+			'ol', 'p', 'picture', 'pre', 'q', 'ruby', 'rp', 'rt', 's', 'samp', 'section',
+			'small', 'source', 'span', 'strike', 'strong', 'sub', 'summary',
+			'sup', 'table', 'tbody', 'td', 'tfoot', 'th', 'thead', 'time',
+			'tr', 'track', 'tt', 'u', 'ul', 'var', 'wbr', 'video', 'xml:namespace' );
+
+		if ($_SESSION['hasSandbox']) $allowed_elements[] = 'iframe';
+
+		$disallowed_attributes = array('id', 'style', 'class', 'width', 'height', 'allow');
+
+		foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_SANITIZE) as $plugin) {
+			$retval = $plugin->hook_sanitize($doc, $site_url, $allowed_elements, $disallowed_attributes, $article_id);
+			if (is_array($retval)) {
+				$doc = $retval[0];
+				$allowed_elements = $retval[1];
+				$disallowed_attributes = $retval[2];
+			} else {
+				$doc = $retval;
+			}
+		}
+
+		$doc->removeChild($doc->firstChild); //remove doctype
+		$doc = Sanitizer::strip_harmful_tags($doc, $allowed_elements, $disallowed_attributes);
+
+		$entries = $xpath->query('//iframe');
+		foreach ($entries as $entry) {
+			$div = $doc->createElement('div');
+			$div->setAttribute('class', 'embed-responsive');
+			$entry->parentNode->replaceChild($div, $entry);
+			$div->appendChild($entry);
+		}
+
+		if ($highlight_words && is_array($highlight_words)) {
+			foreach ($highlight_words as $word) {
+
+				// http://stackoverflow.com/questions/4081372/highlight-keywords-in-a-paragraph
+
+				$elements = $xpath->query("//*/text()");
+
+				foreach ($elements as $child) {
+
+					$fragment = $doc->createDocumentFragment();
+					$text = $child->textContent;
+
+					while (($pos = mb_stripos($text, $word)) !== false) {
+						$fragment->appendChild(new DomText(mb_substr($text, 0, $pos)));
+						$word = mb_substr($text, $pos, mb_strlen($word));
+						$highlight = $doc->createElement('span');
+						$highlight->appendChild(new DomText($word));
+						$highlight->setAttribute('class', 'highlight');
+						$fragment->appendChild($highlight);
+						$text = mb_substr($text, $pos + mb_strlen($word));
+					}
+
+					if (!empty($text)) $fragment->appendChild(new DomText($text));
+
+					$child->parentNode->replaceChild($fragment, $child);
+				}
+			}
+		}
+
+		$res = $doc->saveHTML();
+
+		/* strip everything outside of <body>...</body> */
+
+		$res_frag = array();
+		if (preg_match('/<body>(.*)<\/body>/is', $res, $res_frag)) {
+			return $res_frag[1];
+		} else {
+			return $res;
+		}
+	}
+
+}
diff --git a/classes/urlhelper.php b/classes/urlhelper.php
new file mode 100644
index 000000000..c57d0b9d9
--- /dev/null
+++ b/classes/urlhelper.php
@@ -0,0 +1,474 @@
+<?php
+class UrlHelper {
+	static function build_url($parts) {
+		$tmp = $parts['scheme'] . "://" . $parts['host'] . $parts['path'];
+
+		if (isset($parts['query'])) $tmp .= '?' . $parts['query'];
+		if (isset($parts['fragment'])) $tmp .= '#' . $parts['fragment'];
+
+		return $tmp;
+	}
+
+	/**
+	 * Converts a (possibly) relative URL to a absolute one.
+	 *
+	 * @param string $url     Base URL (i.e. from where the document is)
+	 * @param string $rel_url Possibly relative URL in the document
+	 *
+	 * @return string Absolute URL
+	 */
+	public static function rewrite_relative($url, $rel_url) {
+
+		$rel_parts = parse_url($rel_url);
+
+		if ($rel_parts['host'] && $rel_parts['scheme']) {
+			return UrlHelper::validate($rel_url);
+		} else if (strpos($rel_url, "//") === 0) {
+			# protocol-relative URL (rare but they exist)
+			return UrlHelper::validate("https:" . $rel_url);
+		} else if (strpos($rel_url, "magnet:") === 0) {
+			# allow magnet links
+			return $rel_url;
+		} else {
+			$parts = parse_url($url);
+
+			$rel_parts['host'] = $parts['host'];
+			$rel_parts['scheme'] = $parts['scheme'];
+
+			if (strpos($rel_parts['path'], '/') !== 0)
+				$rel_parts['path'] = '/' . $rel_parts['path'];
+
+			$rel_parts['path'] = str_replace("/./", "/", $rel_parts['path']);
+			$rel_parts['path'] = str_replace("//", "/", $rel_parts['path']);
+
+			return UrlHelper::validate(UrlHelper::build_url($rel_parts));
+		}
+	}
+
+	// extended filtering involves validation for safe ports and loopback
+	static function validate($url, $extended_filtering = false) {
+
+		$url = clean($url);
+
+		# fix protocol-relative URLs
+		if (strpos($url, "//") === 0)
+			$url = "https:" . $url;
+
+		if (filter_var($url, FILTER_VALIDATE_URL) === false)
+			return false;
+
+		$tokens = parse_url($url);
+
+		if (!$tokens['host'])
+			return false;
+
+		if (!in_array(strtolower($tokens['scheme']), ['http', 'https']))
+			return false;
+
+		if ($extended_filtering) {
+			if (!in_array($tokens['port'], [80, 443, '']))
+				return false;
+
+			if (strtolower($tokens['host']) == 'localhost' || $tokens['host'] == '::1' || strpos($tokens['host'], '127.') === 0)
+				return false;
+		}
+
+		//convert IDNA hostname to punycode if possible
+		if (function_exists("idn_to_ascii")) {
+			if (mb_detect_encoding($tokens['host']) != 'ASCII') {
+				$parts['host'] = idn_to_ascii($tokens['host']);
+				$url = UrlHelper::build_url($tokens);
+			}
+		}
+
+		return $url;
+	}
+
+	static function resolve_redirects($url, $timeout, $nest = 0) {
+
+		// too many redirects
+		if ($nest > 10)
+			return false;
+
+		if (version_compare(PHP_VERSION, '7.1.0', '>=')) {
+			$context_options = array(
+				'http' => array(
+					 'header' => array(
+						 'Connection: close'
+					 ),
+					 'method' => 'HEAD',
+					 'timeout' => $timeout,
+					 'protocol_version'=> 1.1)
+				);
+
+			if (defined('_HTTP_PROXY')) {
+				$context_options['http']['request_fulluri'] = true;
+				$context_options['http']['proxy'] = _HTTP_PROXY;
+			}
+
+			$context = stream_context_create($context_options);
+
+			$headers = get_headers($url, 0, $context);
+		} else {
+			$headers = get_headers($url, 0);
+		}
+
+		if (is_array($headers)) {
+			$headers = array_reverse($headers); // last one is the correct one
+
+			foreach($headers as $header) {
+				if (stripos($header, 'Location:') === 0) {
+					$url = UrlHelper::rewrite_relative($url, trim(substr($header, strlen('Location:'))));
+
+					return resolve_redirects($url, $timeout, $nest + 1);
+				}
+			}
+
+			return $url;
+		}
+
+		// request failed?
+		return false;
+	}
+
+		// TODO: max_size currently only works for CURL transfers
+	// TODO: multiple-argument way is deprecated, first parameter is a hash now
+	public static function fetch($options /* previously: 0: $url , 1: $type = false, 2: $login = false, 3: $pass = false,
+				4: $post_query = false, 5: $timeout = false, 6: $timestamp = 0, 7: $useragent = false*/) {
+
+		global $fetch_last_error;
+		global $fetch_last_error_code;
+		global $fetch_last_error_content;
+		global $fetch_last_content_type;
+		global $fetch_last_modified;
+		global $fetch_effective_url;
+		global $fetch_effective_ip_addr;
+		global $fetch_curl_used;
+		global $fetch_domain_hits;
+
+		$fetch_last_error = false;
+		$fetch_last_error_code = -1;
+		$fetch_last_error_content = "";
+		$fetch_last_content_type = "";
+		$fetch_curl_used = false;
+		$fetch_last_modified = "";
+		$fetch_effective_url = "";
+		$fetch_effective_ip_addr = "";
+
+		if (!is_array($fetch_domain_hits))
+			$fetch_domain_hits = [];
+
+		if (!is_array($options)) {
+
+			// falling back on compatibility shim
+			$option_names = [ "url", "type", "login", "pass", "post_query", "timeout", "last_modified", "useragent" ];
+			$tmp = [];
+
+			for ($i = 0; $i < func_num_args(); $i++) {
+				$tmp[$option_names[$i]] = func_get_arg($i);
+			}
+
+			$options = $tmp;
+
+			/*$options = array(
+					"url" => func_get_arg(0),
+					"type" => @func_get_arg(1),
+					"login" => @func_get_arg(2),
+					"pass" => @func_get_arg(3),
+					"post_query" => @func_get_arg(4),
+					"timeout" => @func_get_arg(5),
+					"timestamp" => @func_get_arg(6),
+					"useragent" => @func_get_arg(7)
+			); */
+		}
+
+		$url = $options["url"];
+		$type = isset($options["type"]) ? $options["type"] : false;
+		$login = isset($options["login"]) ? $options["login"] : false;
+		$pass = isset($options["pass"]) ? $options["pass"] : false;
+		$post_query = isset($options["post_query"]) ? $options["post_query"] : false;
+		$timeout = isset($options["timeout"]) ? $options["timeout"] : false;
+		$last_modified = isset($options["last_modified"]) ? $options["last_modified"] : "";
+		$useragent = isset($options["useragent"]) ? $options["useragent"] : false;
+		$followlocation = isset($options["followlocation"]) ? $options["followlocation"] : true;
+		$max_size = isset($options["max_size"]) ? $options["max_size"] : MAX_DOWNLOAD_FILE_SIZE; // in bytes
+		$http_accept = isset($options["http_accept"]) ? $options["http_accept"] : false;
+		$http_referrer = isset($options["http_referrer"]) ? $options["http_referrer"] : false;
+
+		$url = ltrim($url, ' ');
+		$url = str_replace(' ', '%20', $url);
+
+		$url = UrlHelper::validate($url, true);
+
+		if (!$url) {
+			$fetch_last_error = "Requested URL failed extended validation.";
+			return false;
+		}
+
+		$url_host = parse_url($url, PHP_URL_HOST);
+		$ip_addr = gethostbyname($url_host);
+
+		if (!$ip_addr || strpos($ip_addr, "127.") === 0) {
+			$fetch_last_error = "URL hostname failed to resolve or resolved to a loopback address ($ip_addr)";
+			return false;
+		}
+
+		$fetch_domain_hits[$url_host] += 1;
+
+		/*if ($fetch_domain_hits[$url_host] > MAX_FETCH_REQUESTS_PER_HOST) {
+			user_error("Exceeded fetch request quota for $url_host: " . $fetch_domain_hits[$url_host], E_USER_WARNING);
+			#return false;
+		}*/
+
+		if (!defined('NO_CURL') && function_exists('curl_init') && !ini_get("open_basedir")) {
+
+			$fetch_curl_used = true;
+
+			$ch = curl_init($url);
+
+			$curl_http_headers = [];
+
+			if ($last_modified && !$post_query)
+				array_push($curl_http_headers, "If-Modified-Since: $last_modified");
+
+			if ($http_accept)
+				array_push($curl_http_headers, "Accept: " . $http_accept);
+
+			if (count($curl_http_headers) > 0)
+				curl_setopt($ch, CURLOPT_HTTPHEADER, $curl_http_headers);
+
+			curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout ? $timeout : FILE_FETCH_CONNECT_TIMEOUT);
+			curl_setopt($ch, CURLOPT_TIMEOUT, $timeout ? $timeout : FILE_FETCH_TIMEOUT);
+			curl_setopt($ch, CURLOPT_FOLLOWLOCATION, !ini_get("open_basedir") && $followlocation);
+			curl_setopt($ch, CURLOPT_MAXREDIRS, 20);
+			curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
+			curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+			curl_setopt($ch, CURLOPT_HEADER, true);
+			curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
+			curl_setopt($ch, CURLOPT_USERAGENT, $useragent ? $useragent :
+				SELF_USER_AGENT);
+			curl_setopt($ch, CURLOPT_ENCODING, "");
+
+			if  ($http_referrer)
+				curl_setopt($ch, CURLOPT_REFERER, $http_referrer);
+
+			if ($max_size) {
+				curl_setopt($ch, CURLOPT_NOPROGRESS, false);
+				curl_setopt($ch, CURLOPT_BUFFERSIZE, 16384); // needed to get 5 arguments in progress function?
+
+				// holy shit closures in php
+				// download & upload are *expected* sizes respectively, could be zero
+				curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function($curl_handle, $download_size, $downloaded, $upload_size, $uploaded) use( &$max_size) {
+					Debug::log("[curl progressfunction] $downloaded $max_size", Debug::$LOG_EXTENDED);
+
+					return ($downloaded > $max_size) ? 1 : 0; // if max size is set, abort when exceeding it
+				});
+
+			}
+
+			if (!ini_get("open_basedir")) {
+				curl_setopt($ch, CURLOPT_COOKIEJAR, "/dev/null");
+			}
+
+			if (defined('_HTTP_PROXY')) {
+				curl_setopt($ch, CURLOPT_PROXY, _HTTP_PROXY);
+			}
+
+			if ($post_query) {
+				curl_setopt($ch, CURLOPT_POST, true);
+				curl_setopt($ch, CURLOPT_POSTFIELDS, $post_query);
+			}
+
+			if ($login && $pass)
+				curl_setopt($ch, CURLOPT_USERPWD, "$login:$pass");
+
+			$ret = @curl_exec($ch);
+
+			$headers_length = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
+			$headers = explode("\r\n", substr($ret, 0, $headers_length));
+			$contents = substr($ret, $headers_length);
+
+			foreach ($headers as $header) {
+				if (strstr($header, ": ") !== false) {
+					list ($key, $value) = explode(": ", $header);
+
+					if (strtolower($key) == "last-modified") {
+						$fetch_last_modified = $value;
+					}
+				}
+
+				if (substr(strtolower($header), 0, 7) == 'http/1.') {
+					$fetch_last_error_code = (int) substr($header, 9, 3);
+					$fetch_last_error = $header;
+				}
+			}
+
+			if (curl_errno($ch) === 23 || curl_errno($ch) === 61) {
+				curl_setopt($ch, CURLOPT_ENCODING, 'none');
+				$contents = @curl_exec($ch);
+			}
+
+			$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+			$fetch_last_content_type = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
+
+			$fetch_effective_url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);
+
+			if (!UrlHelper::validate($fetch_effective_url, true)) {
+				$fetch_last_error = "URL received after redirection failed extended validation.";
+
+				return false;
+			}
+
+			$fetch_effective_ip_addr = gethostbyname(parse_url($fetch_effective_url, PHP_URL_HOST));
+
+			if (!$fetch_effective_ip_addr || strpos($fetch_effective_ip_addr, "127.") === 0) {
+				$fetch_last_error = "URL hostname received after redirection failed to resolve or resolved to a loopback address ($fetch_effective_ip_addr)";
+
+				return false;
+			}
+
+			$fetch_last_error_code = $http_code;
+
+			if ($http_code != 200 || $type && strpos($fetch_last_content_type, "$type") === false) {
+
+				if (curl_errno($ch) != 0) {
+					$fetch_last_error .=  "; " . curl_errno($ch) . " " . curl_error($ch);
+				}
+
+				$fetch_last_error_content = $contents;
+				curl_close($ch);
+				return false;
+			}
+
+			if (!$contents) {
+				$fetch_last_error = curl_errno($ch) . " " . curl_error($ch);
+				curl_close($ch);
+				return false;
+			}
+
+			curl_close($ch);
+
+			$is_gzipped = RSSUtils::is_gzipped($contents);
+
+			if ($is_gzipped) {
+				$tmp = @gzdecode($contents);
+
+				if ($tmp) $contents = $tmp;
+			}
+
+			return $contents;
+		} else {
+
+			$fetch_curl_used = false;
+
+			if ($login && $pass){
+				$url_parts = array();
+
+				preg_match("/(^[^:]*):\/\/(.*)/", $url, $url_parts);
+
+				$pass = urlencode($pass);
+
+				if ($url_parts[1] && $url_parts[2]) {
+					$url = $url_parts[1] . "://$login:$pass@" . $url_parts[2];
+				}
+			}
+
+			// TODO: should this support POST requests or not? idk
+
+			 $context_options = array(
+				  'http' => array(
+						'header' => array(
+							'Connection: close'
+						),
+						'method' => 'GET',
+						'ignore_errors' => true,
+						'timeout' => $timeout ? $timeout : FILE_FETCH_TIMEOUT,
+						'protocol_version'=> 1.1)
+				  );
+
+			if (!$post_query && $last_modified)
+				array_push($context_options['http']['header'], "If-Modified-Since: $last_modified");
+
+			if ($http_accept)
+				array_push($context_options['http']['header'], "Accept: $http_accept");
+
+			if ($http_referrer)
+				array_push($context_options['http']['header'], "Referer: $http_referrer");
+
+			if (defined('_HTTP_PROXY')) {
+				$context_options['http']['request_fulluri'] = true;
+				$context_options['http']['proxy'] = _HTTP_PROXY;
+			}
+
+			$context = stream_context_create($context_options);
+
+			$old_error = error_get_last();
+
+			$fetch_effective_url = resolve_redirects($url, $timeout ? $timeout : FILE_FETCH_CONNECT_TIMEOUT);
+
+			if (!UrlHelper::validate($fetch_effective_url, true)) {
+				$fetch_last_error = "URL received after redirection failed extended validation.";
+
+				return false;
+			}
+
+			$fetch_effective_ip_addr = gethostbyname(parse_url($fetch_effective_url, PHP_URL_HOST));
+
+			if (!$fetch_effective_ip_addr || strpos($fetch_effective_ip_addr, "127.") === 0) {
+				$fetch_last_error = "URL hostname received after redirection failed to resolve or resolved to a loopback address ($fetch_effective_ip_addr)";
+
+				return false;
+			}
+
+			$data = @file_get_contents($url, false, $context);
+
+			if (isset($http_response_header) && is_array($http_response_header)) {
+				foreach ($http_response_header as $header) {
+					if (strstr($header, ": ") !== false) {
+						list ($key, $value) = explode(": ", $header);
+
+						$key = strtolower($key);
+
+						if ($key == 'content-type') {
+							$fetch_last_content_type = $value;
+							// don't abort here b/c there might be more than one
+							// e.g. if we were being redirected -- last one is the right one
+						} else if ($key == 'last-modified') {
+							$fetch_last_modified = $value;
+						} else if ($key == 'location') {
+							$fetch_effective_url = $value;
+						}
+					}
+
+					if (substr(strtolower($header), 0, 7) == 'http/1.') {
+						$fetch_last_error_code = (int) substr($header, 9, 3);
+						$fetch_last_error = $header;
+					}
+				}
+			}
+
+			if ($fetch_last_error_code != 200) {
+				$error = error_get_last();
+
+				if ($error['message'] != $old_error['message']) {
+					$fetch_last_error .= "; " . $error["message"];
+				}
+
+				$fetch_last_error_content = $data;
+
+				return false;
+			}
+
+			$is_gzipped = RSSUtils::is_gzipped($data);
+
+			if ($is_gzipped) {
+				$tmp = @gzdecode($data);
+
+				if ($tmp) $data = $tmp;
+			}
+
+			return $data;
+		}
+	}
+
+}
diff --git a/classes/userhelper.php b/classes/userhelper.php
new file mode 100644
index 000000000..2ae1f7b83
--- /dev/null
+++ b/classes/userhelper.php
@@ -0,0 +1,141 @@
+<?php
+class UserHelper {
+
+	static function authenticate($login, $password, $check_only = false, $service = false) {
+
+		if (!SINGLE_USER_MODE) {
+			$user_id = false;
+			$auth_module = false;
+
+			foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_AUTH_USER) as $plugin) {
+
+				$user_id = (int) $plugin->authenticate($login, $password, $service);
+
+				if ($user_id) {
+					$auth_module = strtolower(get_class($plugin));
+					break;
+				}
+			}
+
+			if ($user_id && !$check_only) {
+
+				session_start();
+				session_regenerate_id(true);
+
+				$_SESSION["uid"] = $user_id;
+				$_SESSION["auth_module"] = $auth_module;
+
+				$pdo = Db::pdo();
+				$sth = $pdo->prepare("SELECT login,access_level,pwd_hash FROM ttrss_users
+					WHERE id = ?");
+				$sth->execute([$user_id]);
+				$row = $sth->fetch();
+
+				$_SESSION["name"] = $row["login"];
+				$_SESSION["access_level"] = $row["access_level"];
+				$_SESSION["csrf_token"] = bin2hex(get_random_bytes(16));
+
+				$usth = $pdo->prepare("UPDATE ttrss_users SET last_login = NOW() WHERE id = ?");
+				$usth->execute([$user_id]);
+
+				$_SESSION["ip_address"] = $_SERVER["REMOTE_ADDR"];
+				$_SESSION["user_agent"] = sha1($_SERVER['HTTP_USER_AGENT']);
+				$_SESSION["pwd_hash"] = $row["pwd_hash"];
+
+				Pref_Prefs::initialize_user_prefs($_SESSION["uid"]);
+
+				return true;
+			}
+
+			return false;
+
+		} else {
+
+			$_SESSION["uid"] = 1;
+			$_SESSION["name"] = "admin";
+			$_SESSION["access_level"] = 10;
+
+			$_SESSION["hide_hello"] = true;
+			$_SESSION["hide_logout"] = true;
+
+			$_SESSION["auth_module"] = false;
+
+			if (!$_SESSION["csrf_token"])
+				$_SESSION["csrf_token"] = bin2hex(get_random_bytes(16));
+
+			$_SESSION["ip_address"] = $_SERVER["REMOTE_ADDR"];
+
+			Pref_Prefs::initialize_user_prefs($_SESSION["uid"]);
+
+			return true;
+		}
+	}
+
+	static function load_user_plugins($owner_uid, $pluginhost = false) {
+
+		if (!$pluginhost) $pluginhost = PluginHost::getInstance();
+
+		if ($owner_uid && SCHEMA_VERSION >= 100 && !$_SESSION["safe_mode"]) {
+			$plugins = get_pref("_ENABLED_PLUGINS", $owner_uid);
+
+			$pluginhost->load($plugins, PluginHost::KIND_USER, $owner_uid);
+
+			if (get_schema_version() > 100) {
+				$pluginhost->load_data();
+			}
+		}
+	}
+
+	static function login_sequence() {
+		$pdo = Db::pdo();
+
+		if (SINGLE_USER_MODE) {
+			@session_start();
+			UserHelper::authenticate("admin", null);
+			startup_gettext();
+			UserHelper::load_user_plugins($_SESSION["uid"]);
+		} else {
+			if (!validate_session()) $_SESSION["uid"] = false;
+
+			if (!$_SESSION["uid"]) {
+
+				if (AUTH_AUTO_LOGIN && UserHelper::authenticate(null, null)) {
+					$_SESSION["ref_schema_version"] = get_schema_version(true);
+				} else {
+					 UserHelper::authenticate(null, null, true);
+				}
+
+				if (!$_SESSION["uid"]) {
+					Pref_Users::logout_user();
+
+					Handler_Public::render_login_form();
+					exit;
+				}
+
+			} else {
+				/* bump login timestamp */
+				$sth = $pdo->prepare("UPDATE ttrss_users SET last_login = NOW() WHERE id = ?");
+				$sth->execute([$_SESSION['uid']]);
+
+				$_SESSION["last_login_update"] = time();
+			}
+
+			if ($_SESSION["uid"]) {
+				startup_gettext();
+				UserHelper::load_user_plugins($_SESSION["uid"]);
+			}
+		}
+	}
+
+	static function print_user_stylesheet() {
+		$value = get_pref('USER_STYLESHEET');
+
+		if ($value) {
+			print "<style type='text/css' id='user_css_style'>";
+			print str_replace("<br/>", "\n", $value);
+			print "</style>";
+		}
+
+	}
+
+}