Merge pull request #1940 from nextcloud/new-appstore

Use new appstore API

15 files changed, 649 insertions, 891 deletions

diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index 532a6f39848..ddd531868d4 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -279,6 +279,11 @@ return array(
     'OC\\AppFramework\\Utility\\TimeFactory' => $baseDir . '/lib/private/AppFramework/Utility/TimeFactory.php',
     'OC\\AppHelper' => $baseDir . '/lib/private/AppHelper.php',
     'OC\\App\\AppManager' => $baseDir . '/lib/private/App/AppManager.php',
+    'OC\\App\\AppStore\\Fetcher\\AppFetcher' => $baseDir . '/lib/private/App/AppStore/Fetcher/AppFetcher.php',
+    'OC\\App\\AppStore\\Fetcher\\CategoryFetcher' => $baseDir . '/lib/private/App/AppStore/Fetcher/CategoryFetcher.php',
+    'OC\\App\\AppStore\\Fetcher\\Fetcher' => $baseDir . '/lib/private/App/AppStore/Fetcher/Fetcher.php',
+    'OC\\App\\AppStore\\Version\\Version' => $baseDir . '/lib/private/App/AppStore/Version/Version.php',
+    'OC\\App\\AppStore\\Version\\VersionParser' => $baseDir . '/lib/private/App/AppStore/Version/VersionParser.php',
     'OC\\App\\CodeChecker\\AbstractCheck' => $baseDir . '/lib/private/App/CodeChecker/AbstractCheck.php',
     'OC\\App\\CodeChecker\\CodeChecker' => $baseDir . '/lib/private/App/CodeChecker/CodeChecker.php',
     'OC\\App\\CodeChecker\\DeprecationCheck' => $baseDir . '/lib/private/App/CodeChecker/DeprecationCheck.php',
@@ -602,7 +607,6 @@ return array(
     'OC\\Notification\\Action' => $baseDir . '/lib/private/Notification/Action.php',
     'OC\\Notification\\Manager' => $baseDir . '/lib/private/Notification/Manager.php',
     'OC\\Notification\\Notification' => $baseDir . '/lib/private/Notification/Notification.php',
-    'OC\\OCSClient' => $baseDir . '/lib/private/OCSClient.php',
     'OC\\OCS\\CoreCapabilities' => $baseDir . '/lib/private/OCS/CoreCapabilities.php',
     'OC\\OCS\\Exception' => $baseDir . '/lib/private/OCS/Exception.php',
     'OC\\OCS\\Person' => $baseDir . '/lib/private/OCS/Person.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index c0a3e9b50c6..99a3c3d540e 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -309,6 +309,11 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\AppFramework\\Utility\\TimeFactory' => __DIR__ . '/../../..' . '/lib/private/AppFramework/Utility/TimeFactory.php',
         'OC\\AppHelper' => __DIR__ . '/../../..' . '/lib/private/AppHelper.php',
         'OC\\App\\AppManager' => __DIR__ . '/../../..' . '/lib/private/App/AppManager.php',
+        'OC\\App\\AppStore\\Fetcher\\AppFetcher' => __DIR__ . '/../../..' . '/lib/private/App/AppStore/Fetcher/AppFetcher.php',
+        'OC\\App\\AppStore\\Fetcher\\CategoryFetcher' => __DIR__ . '/../../..' . '/lib/private/App/AppStore/Fetcher/CategoryFetcher.php',
+        'OC\\App\\AppStore\\Fetcher\\Fetcher' => __DIR__ . '/../../..' . '/lib/private/App/AppStore/Fetcher/Fetcher.php',
+        'OC\\App\\AppStore\\Version\\Version' => __DIR__ . '/../../..' . '/lib/private/App/AppStore/Version/Version.php',
+        'OC\\App\\AppStore\\Version\\VersionParser' => __DIR__ . '/../../..' . '/lib/private/App/AppStore/Version/VersionParser.php',
         'OC\\App\\CodeChecker\\AbstractCheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/AbstractCheck.php',
         'OC\\App\\CodeChecker\\CodeChecker' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/CodeChecker.php',
         'OC\\App\\CodeChecker\\DeprecationCheck' => __DIR__ . '/../../..' . '/lib/private/App/CodeChecker/DeprecationCheck.php',
@@ -632,7 +637,6 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Notification\\Action' => __DIR__ . '/../../..' . '/lib/private/Notification/Action.php',
         'OC\\Notification\\Manager' => __DIR__ . '/../../..' . '/lib/private/Notification/Manager.php',
         'OC\\Notification\\Notification' => __DIR__ . '/../../..' . '/lib/private/Notification/Notification.php',
-        'OC\\OCSClient' => __DIR__ . '/../../..' . '/lib/private/OCSClient.php',
         'OC\\OCS\\CoreCapabilities' => __DIR__ . '/../../..' . '/lib/private/OCS/CoreCapabilities.php',
         'OC\\OCS\\Exception' => __DIR__ . '/../../..' . '/lib/private/OCS/Exception.php',
         'OC\\OCS\\Person' => __DIR__ . '/../../..' . '/lib/private/OCS/Person.php',
diff --git a/lib/private/App/AppStore/Fetcher/AppFetcher.php b/lib/private/App/AppStore/Fetcher/AppFetcher.php
new file mode 100644
index 00000000000..19e61d416a0
--- /dev/null
+++ b/lib/private/App/AppStore/Fetcher/AppFetcher.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\AppStore\Fetcher;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Files\IAppData;
+use OCP\Http\Client\IClientService;
+use OCP\IConfig;
+
+class AppFetcher extends Fetcher {
+	/**
+	 * @param IAppData $appData
+	 * @param IClientService $clientService
+	 * @param ITimeFactory $timeFactory
+	 * @param IConfig $config;
+	 */
+	public function __construct(IAppData $appData,
+								IClientService $clientService,
+								ITimeFactory $timeFactory,
+								IConfig $config) {
+		parent::__construct(
+			$appData,
+			$clientService,
+			$timeFactory
+		);
+
+		$this->fileName = 'apps.json';
+
+		$versionArray = \OC_Util::getVersion();
+		$this->endpointUrl = sprintf(
+			'https://apps.nextcloud.com/api/v1/platform/%d.%d.%d/apps.json',
+			$versionArray[0],
+			$versionArray[1],
+			$versionArray[2]
+		);
+	}
+}
diff --git a/lib/private/App/AppStore/Fetcher/CategoryFetcher.php b/lib/private/App/AppStore/Fetcher/CategoryFetcher.php
new file mode 100644
index 00000000000..74201ec3737
--- /dev/null
+++ b/lib/private/App/AppStore/Fetcher/CategoryFetcher.php
@@ -0,0 +1,45 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\AppStore\Fetcher;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Files\IAppData;
+use OCP\Http\Client\IClientService;
+
+class CategoryFetcher extends Fetcher {
+	/**
+	 * @param IAppData $appData
+	 * @param IClientService $clientService
+	 * @param ITimeFactory $timeFactory
+	 */
+	public function __construct(IAppData $appData,
+								IClientService $clientService,
+								ITimeFactory $timeFactory) {
+		parent::__construct(
+			$appData,
+			$clientService,
+			$timeFactory
+		);
+		$this->fileName = 'categories.json';
+		$this->endpointUrl = 'https://apps.nextcloud.com/api/v1/categories.json';
+	}
+}
diff --git a/lib/private/App/AppStore/Fetcher/Fetcher.php b/lib/private/App/AppStore/Fetcher/Fetcher.php
new file mode 100644
index 00000000000..cffff9176e2
--- /dev/null
+++ b/lib/private/App/AppStore/Fetcher/Fetcher.php
@@ -0,0 +1,92 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\AppStore\Fetcher;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Files\IAppData;
+use OCP\Files\NotFoundException;
+use OCP\Http\Client\IClientService;
+
+abstract class Fetcher {
+	const INVALIDATE_AFTER_SECONDS = 300;
+
+	/** @var IAppData */
+	private $appData;
+	/** @var IClientService */
+	private $clientService;
+	/** @var ITimeFactory */
+	private $timeFactory;
+	/** @var string */
+	protected $fileName;
+	/** @var string */
+	protected $endpointUrl;
+
+	/**
+	 * @param IAppData $appData
+	 * @param IClientService $clientService
+	 * @param ITimeFactory $timeFactory
+	 */
+	public function __construct(IAppData $appData,
+								IClientService $clientService,
+								ITimeFactory $timeFactory) {
+		$this->appData = $appData;
+		$this->clientService = $clientService;
+		$this->timeFactory = $timeFactory;
+	}
+
+	/**
+	 * Returns the array with the categories on the appstore server
+	 *
+	 * @return array
+	 */
+	 public function get() {
+		$rootFolder = $this->appData->getFolder('/');
+
+		try {
+			// File does already exists
+			$file = $rootFolder->getFile($this->fileName);
+			$jsonBlob = json_decode($file->getContent(), true);
+			if(is_array($jsonBlob)) {
+				// If the timestamp is older than 300 seconds request the files new
+				if((int)$jsonBlob['timestamp'] > ($this->timeFactory->getTime() - self::INVALIDATE_AFTER_SECONDS)) {
+					return $jsonBlob['data'];
+				}
+			}
+		} catch (NotFoundException $e) {
+			// File does not already exists
+			$file = $rootFolder->newFile($this->fileName);
+		}
+
+		// Refresh the file content
+		$client = $this->clientService->newClient();
+		try {
+			$response = $client->get($this->endpointUrl);
+			$responseJson = [];
+			$responseJson['data'] = json_decode($response->getBody(), true);
+			$responseJson['timestamp'] = $this->timeFactory->getTime();
+			$file->putContent(json_encode($responseJson));
+			return json_decode($file->getContent(), true)['data'];
+		} catch (\Exception $e) {
+			return [];
+		}
+	}
+}
diff --git a/lib/private/App/AppStore/Version/Version.php b/lib/private/App/AppStore/Version/Version.php
new file mode 100644
index 00000000000..ca182ae078b
--- /dev/null
+++ b/lib/private/App/AppStore/Version/Version.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\AppStore\Version;
+
+class Version {
+	/** @var string */
+	private $minVersion;
+	/** @var string */
+	private $maxVersion;
+
+	/**
+	 * @param string $minVersion
+	 * @param string $maxVersion
+	 */
+	public function __construct($minVersion, $maxVersion) {
+		$this->minVersion = $minVersion;
+		$this->maxVersion = $maxVersion;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getMinimumVersion() {
+		return $this->minVersion;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getMaximumVersion() {
+		return $this->maxVersion;
+	}
+}
diff --git a/lib/private/App/AppStore/Version/VersionParser.php b/lib/private/App/AppStore/Version/VersionParser.php
new file mode 100644
index 00000000000..b548ef386d9
--- /dev/null
+++ b/lib/private/App/AppStore/Version/VersionParser.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Lukas Reschke <lukas@statuscode.ch>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\App\AppStore\Version;
+
+/**
+ * Class VersionParser parses the versions as sent by the Nextcloud app store
+ *
+ * @package OC\App\AppStore
+ */
+class VersionParser {
+	/**
+	 * @param string $versionString
+	 * @return bool
+	 */
+	private function isValidVersionString($versionString) {
+		return (bool)preg_match('/^[0-9.]+$/', $versionString);
+	}
+
+	/**
+	 * Returns the version for a version string
+	 *
+	 * @param string $versionSpec
+	 * @return Version
+	 * @throws \Exception If the version cannot be parsed
+	 */
+	public function getVersion($versionSpec) {
+		// * indicates that the version is compatible with all versions
+		if($versionSpec === '*') {
+			return new Version('', '');
+		}
+
+		// Count the amount of =, if it is one then it's either maximum or minimum
+		// version. If it is two then it is maximum and minimum.
+		$versionElements = explode(' ', $versionSpec);
+		$firstVersion = isset($versionElements[0]) ? $versionElements[0] : '';
+		$firstVersionNumber = substr($firstVersion, 2);
+		$secondVersion = isset($versionElements[1]) ? $versionElements[1] : '';
+		$secondVersionNumber = substr($secondVersion, 2);
+
+		switch(count($versionElements)) {
+			case 1:
+				if(!$this->isValidVersionString($firstVersionNumber)) {
+					break;
+				}
+				if(substr($firstVersion, 0, 1) === '>') {
+					return new Version($firstVersionNumber, '');
+				} else {
+					return new Version('', $firstVersionNumber);
+				}
+			case 2:
+				if(!$this->isValidVersionString($firstVersionNumber) || !$this->isValidVersionString($secondVersionNumber)) {
+					break;
+				}
+				return new Version($firstVersionNumber, $secondVersionNumber);
+		}
+
+		throw new \Exception(
+			sprintf(
+				'Version cannot be parsed: %s',
+				$versionSpec
+			)
+		);
+	}
+}
diff --git a/lib/private/App/DependencyAnalyzer.php b/lib/private/App/DependencyAnalyzer.php
index 67268981e99..c24b25ff14d 100644
--- a/lib/private/App/DependencyAnalyzer.php
+++ b/lib/private/App/DependencyAnalyzer.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
  *
  * @author Bernhard Posselt <dev@bernhard-posselt.com>
  * @author Joas Schilling <coding@schilljs.com>
@@ -294,7 +295,9 @@ class DependencyAnalyzer {
 	private function analyzeOC(array $dependencies, array $appInfo) {
 		$missing = [];
 		$minVersion = null;
-		if (isset($dependencies['owncloud']['@attributes']['min-version'])) {
+		if (isset($dependencies['nextcloud']['@attributes']['min-version'])) {
+			$minVersion = $dependencies['nextcloud']['@attributes']['min-version'];
+		} elseif (isset($dependencies['owncloud']['@attributes']['min-version'])) {
 			$minVersion = $dependencies['owncloud']['@attributes']['min-version'];
 		} elseif (isset($appInfo['requiremin'])) {
 			$minVersion = $appInfo['requiremin'];
@@ -302,7 +305,9 @@ class DependencyAnalyzer {
 			$minVersion = $appInfo['require'];
 		}
 		$maxVersion = null;
-		if (isset($dependencies['owncloud']['@attributes']['max-version'])) {
+		if (isset($dependencies['nextcloud']['@attributes']['max-version'])) {
+			$maxVersion = $dependencies['nextcloud']['@attributes']['max-version'];
+		} elseif (isset($dependencies['owncloud']['@attributes']['max-version'])) {
 			$maxVersion = $dependencies['owncloud']['@attributes']['max-version'];
 		} elseif (isset($appInfo['requiremax'])) {
 			$maxVersion = $appInfo['requiremax'];
diff --git a/lib/private/Archive/Archive.php b/lib/private/Archive/Archive.php
index da2c53f2aa1..fadc12d2a24 100644
--- a/lib/private/Archive/Archive.php
+++ b/lib/private/Archive/Archive.php
@@ -32,26 +32,7 @@
 
 namespace OC\Archive;
 
-abstract class Archive{
-	/**
-	 * Open any of the supported archive types
-	 *
-	 * @param string $path
-	 * @return Archive|void
-	 */
-	public static function open($path) {
-		$mime = \OC::$server->getMimeTypeDetector()->detect($path);
-
-		switch($mime) {
-			case 'application/zip':
-				return new ZIP($path);
-			case 'application/x-gzip':
-				return new TAR($path);
-			case 'application/x-bzip2':
-				return new TAR($path);
-		}
-	}
-
+abstract class Archive {
 	/**
 	 * @param $source
 	 */
diff --git a/lib/private/Installer.php b/lib/private/Installer.php
index 009df790585..2366b762654 100644
--- a/lib/private/Installer.php
+++ b/lib/private/Installer.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
  *
  * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
  * @author Bart Visscher <bartv@thisnet.nl>
@@ -40,90 +41,64 @@
 
 namespace OC;
 
+use OC\App\AppStore\Fetcher\AppFetcher;
 use OC\App\CodeChecker\CodeChecker;
 use OC\App\CodeChecker\EmptyCheck;
 use OC\App\CodeChecker\PrivateCheck;
+use OC\Archive\Archive;
+use OC\Archive\TAR;
 use OC_App;
 use OC_DB;
 use OC_Helper;
+use OCP\Http\Client\IClientService;
+use OCP\ILogger;
+use OCP\ITempManager;
+use phpseclib\File\X509;
 
 /**
- * This class provides the functionality needed to install, update and remove plugins/apps
+ * This class provides the functionality needed to install, update and remove apps
  */
 class Installer {
+	/** @var AppFetcher */
+	private $appFetcher;
+	/** @var IClientService */
+	private $clientService;
+	/** @var ITempManager */
+	private $tempManager;
+	/** @var ILogger */
+	private $logger;
 
 	/**
+	 * @param AppFetcher $appFetcher
+	 * @param IClientService $clientService
+	 * @param ITempManager $tempManager
+	 * @param ILogger $logger
+	 */
+	public function __construct(AppFetcher $appFetcher,
+								IClientService $clientService,
+								ITempManager $tempManager,
+								ILogger $logger) {
+		$this->appFetcher = $appFetcher;
+		$this->clientService = $clientService;
+		$this->tempManager = $tempManager;
+		$this->logger = $logger;
+	}
+
+	/**
+	 * Installs an app that is located in one of the app folders already
 	 *
-	 * This function installs an app. All information needed are passed in the
-	 * associative array $data.
-	 * The following keys are required:
-	 *   - source: string, can be "path" or "http"
-	 *
-	 * One of the following keys is required:
-	 *   - path: path to the file containing the app
-	 *   - href: link to the downloadable file containing the app
-	 *
-	 * The following keys are optional:
-	 *   - pretend: boolean, if set true the system won't do anything
-	 *   - noinstall: boolean, if true appinfo/install.php won't be loaded
-	 *   - inactive: boolean, if set true the appconfig/app.sample.php won't be
-	 *     renamed
-	 *
-	 * This function works as follows
-	 *   -# fetching the file
-	 *   -# unzipping it
-	 *   -# check the code
-	 *   -# installing the database at appinfo/database.xml
-	 *   -# including appinfo/install.php
-	 *   -# setting the installed version
-	 *
-	 * It is the task of oc_app_install to create the tables and do whatever is
-	 * needed to get the app working.
-	 *
-	 * Installs an app
-	 * @param array $data with all information
+	 * @param string $appId App to install
 	 * @throws \Exception
 	 * @return integer
 	 */
-	public static function installApp( $data = array()) {
-		$l = \OC::$server->getL10N('lib');
-
-		list($extractDir, $path) = self::downloadApp($data);
-
-		$info = self::checkAppsIntegrity($data, $extractDir, $path);
-		$appId = OC_App::cleanAppId($info['id']);
-		$basedir = OC_App::getInstallPath().'/'.$appId;
-		//check if the destination directory already exists
-		if(is_dir($basedir)) {
-			OC_Helper::rmdirr($extractDir);
-			if($data['source']=='http') {
-				unlink($path);
-			}
-			throw new \Exception($l->t("App directory already exists"));
-		}
-
-		if(!empty($data['pretent'])) {
-			return false;
+	public function installApp($appId) {
+		$app = \OC_App::findAppInDirectories($appId);
+		if($app === false) {
+			throw new \Exception('App not found in any app directory');
 		}
 
-		//copy the app to the correct place
-		if(@!mkdir($basedir)) {
-			OC_Helper::rmdirr($extractDir);
-			if($data['source']=='http') {
-				unlink($path);
-			}
-			throw new \Exception($l->t("Can't create app folder. Please fix permissions. %s", array($basedir)));
-		}
-
-		$extractDir .= '/' . $info['id'];
-		if(!file_exists($extractDir)) {
-			OC_Helper::rmdirr($basedir);
-			throw new \Exception($l->t("Archive does not contain a directory named %s", $info['id']));
-		}
-		OC_Helper::copyr($extractDir, $basedir);
-
-		//remove temporary files
-		OC_Helper::rmdirr($extractDir);
+		$basedir = $app['path'].'/'.$appId;
+		$info = OC_App::getAppInfo($basedir.'/appinfo/info.xml', true);
 
 		//install the database
 		if(is_file($basedir.'/appinfo/database.xml')) {
@@ -168,259 +143,189 @@ class Installer {
 	 *
 	 * Checks whether or not an app is installed, i.e. registered in apps table.
 	 */
-	public static function 	isInstalled( $app ) {
+	public static function isInstalled( $app ) {
 		return (\OC::$server->getConfig()->getAppValue($app, "installed_version", null) !== null);
 	}
 
 	/**
-	 * @brief Update an application
-	 * @param array $info
-	 * @param bool $isShipped
-	 * @throws \Exception
-	 * @return bool
-	 *
-	 * This function could work like described below, but currently it disables and then
-	 * enables the app again. This does result in an updated app.
-	 *
-	 *
-	 * This function installs an app. All information needed are passed in the
-	 * associative array $info.
-	 * The following keys are required:
-	 *   - source: string, can be "path" or "http"
-	 *
-	 * One of the following keys is required:
-	 *   - path: path to the file containing the app
-	 *   - href: link to the downloadable file containing the app
-	 *
-	 * The following keys are optional:
-	 *   - pretend: boolean, if set true the system won't do anything
-	 *   - noupgrade: boolean, if true appinfo/upgrade.php won't be loaded
-	 *
-	 * This function works as follows
-	 *   -# fetching the file
-	 *   -# removing the old files
-	 *   -# unzipping new file
-	 *   -# including appinfo/upgrade.php
-	 *   -# setting the installed version
-	 *
-	 * upgrade.php can determine the current installed version of the app using
-	 * "\OC::$server->getAppConfig()->getValue($appid, 'installed_version')"
-	 */
-	public static function updateApp($info=array(), $isShipped=false) {
-		list($extractDir, $path) = self::downloadApp($info);
-		$info = self::checkAppsIntegrity($info, $extractDir, $path, $isShipped);
-
-		$currentDir = OC_App::getAppPath($info['id']);
-		$basedir  = OC_App::getInstallPath();
-		$basedir .= '/';
-		$basedir .= $info['id'];
-
-		if($currentDir !== false && is_writable($currentDir)) {
-			$basedir = $currentDir;
-		}
-		if(is_dir($basedir)) {
-			OC_Helper::rmdirr($basedir);
-		}
-
-		$appInExtractDir = $extractDir;
-		if (substr($extractDir, -1) !== '/') {
-			$appInExtractDir .= '/';
-		}
-
-		$appInExtractDir .= $info['id'];
-		OC_Helper::copyr($appInExtractDir, $basedir);
-		OC_Helper::rmdirr($extractDir);
-
-		return OC_App::updateApp($info['id']);
-	}
-
-	/**
-	 * update an app by it's id
+	 * Updates the specified app from the appstore
 	 *
-	 * @param integer $ocsId
+	 * @param string $appId
 	 * @return bool
-	 * @throws \Exception
 	 */
-	public static function updateAppByOCSId($ocsId) {
-		$ocsClient = new OCSClient(
-			\OC::$server->getHTTPClientService(),
-			\OC::$server->getConfig(),
-			\OC::$server->getLogger()
-		);
-		$appData = $ocsClient->getApplication($ocsId, \OCP\Util::getVersion());
-		$download = $ocsClient->getApplicationDownload($ocsId, \OCP\Util::getVersion());
-
-		if (isset($download['downloadlink']) && trim($download['downloadlink']) !== '') {
-			$download['downloadlink'] = str_replace(' ', '%20', $download['downloadlink']);
-			$info = array(
-				'source' => 'http',
-				'href' => $download['downloadlink'],
-				'appdata' => $appData
-			);
-		} else {
-			throw new \Exception('Could not fetch app info!');
+	public function updateAppstoreApp($appId) {
+		if(self::isUpdateAvailable($appId, $this->appFetcher)) {
+			try {
+				$this->downloadApp($appId);
+			} catch (\Exception $e) {
+				$this->logger->error($e->getMessage(), ['app' => 'core']);
+				return false;
+			}
+			return OC_App::updateApp($appId);
 		}
 
-		return self::updateApp($info);
+		return false;
 	}
 
 	/**
-	 * @param array $data
-	 * @return array
-	 * @throws \Exception
+	 * Downloads an app and puts it into the app directory
+	 *
+	 * @param string $appId
+	 *
+	 * @throws \Exception If the installation was not successful
 	 */
-	public static function downloadApp($data = array()) {
-		$l = \OC::$server->getL10N('lib');
-
-		if(!isset($data['source'])) {
-			throw new \Exception($l->t("No source specified when installing app"));
-		}
+	public function downloadApp($appId) {
+		$appId = strtolower($appId);
+
+		$apps = $this->appFetcher->get();
+		foreach($apps as $app) {
+			if($app['id'] === $appId) {
+				// Load the certificate
+				$certificate = new X509();
+				$certificate->loadCA(file_get_contents(__DIR__ . '/../../resources/codesigning/root.crt'));
+				$loadedCertificate = $certificate->loadX509($app['certificate']);
+
+				// Verify if the certificate has been revoked
+				$crl = new X509();
+				$crl->loadCA(file_get_contents(__DIR__ . '/../../resources/codesigning/root.crt'));
+				$crl->loadCRL(file_get_contents(__DIR__ . '/../../resources/codesigning/root.crl'));
+				if($crl->validateSignature() !== true) {
+					throw new \Exception('Could not validate CRL signature');
+				}
+				$csn = $loadedCertificate['tbsCertificate']['serialNumber']->toString();
+				$revoked = $crl->getRevoked($csn);
+				if ($revoked !== false) {
+					throw new \Exception(
+						sprintf(
+							'Certificate "%s" has been revoked',
+							$csn
+						)
+					);
+				}
 
-		//download the file if necessary
-		if($data['source']=='http') {
-			$pathInfo = pathinfo($data['href']);
-			$extension = isset($pathInfo['extension']) ? '.' . $pathInfo['extension'] : '';
-			$path = \OC::$server->getTempManager()->getTemporaryFile($extension);
-			if(!isset($data['href'])) {
-				throw new \Exception($l->t("No href specified when installing app from http"));
-			}
-			$client = \OC::$server->getHTTPClientService()->newClient();
-			$client->get($data['href'], ['save_to' => $path]);
-		} else {
-			if(!isset($data['path'])) {
-				throw new \Exception($l->t("No path specified when installing app from local file"));
-			}
-			$path=$data['path'];
-		}
+				// Verify if the certificate has been issued by the Nextcloud Code Authority CA
+				if($certificate->validateSignature() !== true) {
+					throw new \Exception(
+						sprintf(
+							'App with id %s has a certificate not issued by a trusted Code Signing Authority',
+							$appId
+						)
+					);
+				}
 
-		//detect the archive type
-		$mime = \OC::$server->getMimeTypeDetector()->detect($path);
-		if ($mime !=='application/zip' && $mime !== 'application/x-gzip' && $mime !== 'application/x-bzip2') {
-			throw new \Exception($l->t("Archives of type %s are not supported", array($mime)));
-		}
+				// Verify if the certificate is issued for the requested app id
+				$certInfo = openssl_x509_parse($app['certificate']);
+				if(!isset($certInfo['subject']['CN'])) {
+					throw new \Exception(
+						sprintf(
+							'App with id %s has a cert with no CN',
+							$appId
+						)
+					);
+				}
+				if($certInfo['subject']['CN'] !== $appId) {
+					throw new \Exception(
+						sprintf(
+							'App with id %s has a cert issued to %s',
+							$appId,
+							$certInfo['subject']['CN']
+						)
+					);
+				}
 
-		//extract the archive in a temporary folder
-		$extractDir = \OC::$server->getTempManager()->getTemporaryFolder();
-		OC_Helper::rmdirr($extractDir);
-		mkdir($extractDir);
-		if($archive=\OC\Archive\Archive::open($path)) {
-			$archive->extract($extractDir);
-		} else {
-			OC_Helper::rmdirr($extractDir);
-			if($data['source']=='http') {
-				unlink($path);
-			}
-			throw new \Exception($l->t("Failed to open archive when installing app"));
-		}
+				// Download the release
+				$tempFile = $this->tempManager->getTemporaryFile('.tar.gz');
+				$client = $this->clientService->newClient();
+				$client->get($app['releases'][0]['download'], ['save_to' => $tempFile]);
+
+				// Check if the signature actually matches the downloaded content
+				$certificate = openssl_get_publickey($app['certificate']);
+				$verified = (bool)openssl_verify(file_get_contents($tempFile), base64_decode($app['releases'][0]['signature']), $certificate, OPENSSL_ALGO_SHA512);
+				openssl_free_key($certificate);
+
+				if($verified === true) {
+					// Seems to match, let's proceed
+					$extractDir = $this->tempManager->getTemporaryFolder();
+					$archive = new TAR($tempFile);
+
+					if($archive) {
+						$archive->extract($extractDir);
+						$allFiles = scandir($extractDir);
+						$folders = array_diff($allFiles, ['.', '..']);
+						$folders = array_values($folders);
+
+						if(count($folders) > 1) {
+							throw new \Exception(
+								sprintf(
+									'Extracted app %s has more than 1 folder',
+									$appId
+								)
+							);
+						}
 
-		return array(
-			$extractDir,
-			$path
-		);
-	}
+						// Check if appinfo/info.xml has the same app ID as well
+						$loadEntities = libxml_disable_entity_loader(false);
+						$xml = simplexml_load_file($extractDir . '/' . $folders[0] . '/appinfo/info.xml');
+						libxml_disable_entity_loader($loadEntities);
+						if((string)$xml->id !== $appId) {
+							throw new \Exception(
+								sprintf(
+									'App for id %s has a wrong app ID in info.xml: %s',
+									$appId,
+									(string)$xml->id
+								)
+							);
+						}
 
-	/**
-	 * check an app's integrity
-	 * @param array $data
-	 * @param string $extractDir
-	 * @param string $path
-	 * @param bool $isShipped
-	 * @return array
-	 * @throws \Exception
-	 */
-	public static function checkAppsIntegrity($data, $extractDir, $path, $isShipped = false) {
-		$l = \OC::$server->getL10N('lib');
-		//load the info.xml file of the app
-		if(!is_file($extractDir.'/appinfo/info.xml')) {
-			//try to find it in a subdir
-			$dh=opendir($extractDir);
-			if(is_resource($dh)) {
-				while (($folder = readdir($dh)) !== false) {
-					if($folder[0]!='.' and is_dir($extractDir.'/'.$folder)) {
-						if(is_file($extractDir.'/'.$folder.'/appinfo/info.xml')) {
-							$extractDir.='/'.$folder;
+						$baseDir = OC_App::getInstallPath() . '/' . $appId;
+						// Remove old app with the ID if existent
+						OC_Helper::rmdirr($baseDir);
+						// Move to app folder
+						if(@mkdir($baseDir)) {
+							$extractDir .= '/' . $folders[0];
+							OC_Helper::copyr($extractDir, $baseDir);
 						}
+						OC_Helper::copyr($extractDir, $baseDir);
+						OC_Helper::rmdirr($extractDir);
+						return;
+					} else {
+						throw new \Exception(
+							sprintf(
+								'Could not extract app with ID %s to %s',
+								$appId,
+								$extractDir
+							)
+						);
 					}
-				}
-			}
-		}
-		if(!is_file($extractDir.'/appinfo/info.xml')) {
-			OC_Helper::rmdirr($extractDir);
-			if($data['source'] === 'http') {
-				unlink($path);
-			}
-			throw new \Exception($l->t("App does not provide an info.xml file"));
-		}
-
-		$info = OC_App::getAppInfo($extractDir.'/appinfo/info.xml', true);
-		if(!is_array($info)) {
-			throw new \Exception($l->t('App cannot be installed because appinfo file cannot be read.'));
-		}
-
-		// We can't trust the parsed info.xml file as it may have been tampered
-		// with by an attacker and thus we need to use the local data to check
-		// whether the application needs to be signed.
-		$appId = OC_App::cleanAppId($data['appdata']['id']);
-		$appBelongingToId = OC_App::getInternalAppIdByOcs($appId);
-		if(is_string($appBelongingToId)) {
-			$previouslySigned = \OC::$server->getConfig()->getAppValue($appBelongingToId, 'signed', 'false');
-		} else {
-			$appBelongingToId = $info['id'];
-			$previouslySigned = 'false';
-		}
-		if($data['appdata']['level'] === OC_App::officialApp || $previouslySigned === 'true') {
-			\OC::$server->getConfig()->setAppValue($appBelongingToId, 'signed', 'true');
-			$integrityResult = \OC::$server->getIntegrityCodeChecker()->verifyAppSignature(
-					$appBelongingToId,
-					$extractDir
-			);
-			if($integrityResult !== []) {
-				$e = new \Exception(
-						$l->t(
-								'Signature could not get checked. Please contact the app developer and check your admin screen.'
+				} else {
+					// Signature does not match
+					throw new \Exception(
+						sprintf(
+							'App with id %s has invalid signature',
+							$appId
 						)
-				);
-				throw $e;
+					);
+				}
 			}
 		}
 
-		// check the code for not allowed calls
-		if(!$isShipped && !Installer::checkCode($extractDir)) {
-			OC_Helper::rmdirr($extractDir);
-			throw new \Exception($l->t("App can't be installed because of not allowed code in the App"));
-		}
-
-		// check if the app is compatible with this version of ownCloud
-		if(!OC_App::isAppCompatible(\OCP\Util::getVersion(), $info)) {
-			OC_Helper::rmdirr($extractDir);
-			throw new \Exception($l->t("App can't be installed because it is not compatible with this version of the server"));
-		}
-
-		// check if shipped tag is set which is only allowed for apps that are shipped with ownCloud
-		if(!$isShipped && isset($info['shipped']) && ($info['shipped']=='true')) {
-			OC_Helper::rmdirr($extractDir);
-			throw new \Exception($l->t("App can't be installed because it contains the <shipped>true</shipped> tag which is not allowed for non shipped apps"));
-		}
-
-		// check if the ocs version is the same as the version in info.xml/version
-		$version = trim($info['version']);
-
-		if(isset($data['appdata']['version']) && $version<>trim($data['appdata']['version'])) {
-			OC_Helper::rmdirr($extractDir);
-			throw new \Exception($l->t("App can't be installed because the version in info.xml is not the same as the version reported from the app store"));
-		}
-
-		return $info;
+		throw new \Exception(
+			sprintf(
+				'Could not download app %s',
+				$appId
+			)
+		);
 	}
 
 	/**
 	 * Check if an update for the app is available
-	 * @param string $app
-	 * @return string|false false or the version number of the update
 	 *
-	 * The function will check if an update for a version is available
+	 * @param string $appId
+	 * @param AppFetcher $appFetcher
+	 * @return string|false false or the version number of the update
 	 */
-	public static function isUpdateAvailable( $app ) {
+	public static function isUpdateAvailable($appId,
+									  AppFetcher $appFetcher) {
 		static $isInstanceReadyForUpdates = null;
 
 		if ($isInstanceReadyForUpdates === null) {
@@ -436,27 +341,20 @@ class Installer {
 			return false;
 		}
 
-		$ocsid=\OC::$server->getAppConfig()->getValue( $app, 'ocsid', '');
-
-		if($ocsid<>'') {
-			$ocsClient = new OCSClient(
-				\OC::$server->getHTTPClientService(),
-				\OC::$server->getConfig(),
-				\OC::$server->getLogger()
-			);
-			$ocsdata = $ocsClient->getApplication($ocsid, \OCP\Util::getVersion());
-			$ocsversion= (string) $ocsdata['version'];
-			$currentversion=OC_App::getAppVersion($app);
-			if (version_compare($ocsversion, $currentversion, '>')) {
-				return($ocsversion);
-			}else{
-				return false;
+		$apps = $appFetcher->get();
+		foreach($apps as $app) {
+			if($app['id'] === $appId) {
+				$currentVersion = OC_App::getAppVersion($appId);
+				$newestVersion = $app['releases'][0]['version'];
+				if (version_compare($newestVersion, $currentVersion, '>')) {
+					return $newestVersion;
+				} else {
+					return false;
+				}
 			}
-
-		}else{
-			return false;
 		}
 
+		return false;
 	}
 
 	/**
@@ -466,7 +364,7 @@ class Installer {
 	 *
 	 * The function will check if the app is already downloaded in the apps repository
 	 */
-	public static function isDownloaded( $name ) {
+	public function isDownloaded($name) {
 		foreach(\OC::$APPSROOTS as $dir) {
 			$dirToTest  = $dir['path'];
 			$dirToTest .= '/';
@@ -483,7 +381,7 @@ class Installer {
 
 	/**
 	 * Removes an app
-	 * @param string $name name of the application to remove
+	 * @param string $appId ID of the application to remove
 	 * @return boolean
 	 *
 	 *
@@ -494,12 +392,10 @@ class Installer {
 	 * The function will not delete preferences, tables and the configuration,
 	 * this has to be done by the function oc_app_uninstall().
 	 */
-	public static function removeApp($appId) {
-
-		if(Installer::isDownloaded( $appId )) {
-			$appDir=OC_App::getInstallPath() . '/' . $appId;
+	public function removeApp($appId) {
+		if($this->isDownloaded( $appId )) {
+			$appDir = OC_App::getInstallPath() . '/' . $appId;
 			OC_Helper::rmdirr($appDir);
-
 			return true;
 		}else{
 			\OCP\Util::writeLog('core', 'can\'t remove app '.$appId.'. It is not installed.', \OCP\Util::ERROR);
@@ -620,7 +516,7 @@ class Installer {
 	}
 
 	/**
-	 * @param $basedir
+	 * @param string $script
 	 */
 	private static function includeAppScript($script) {
 		if ( file_exists($script) ){
diff --git a/lib/private/OCSClient.php b/lib/private/OCSClient.php
deleted file mode 100644
index 76c0b136c06..00000000000
--- a/lib/private/OCSClient.php
+++ /dev/null
@@ -1,351 +0,0 @@
-<?php
-/**
- * @copyright Copyright (c) 2016, ownCloud, Inc.
- *
- * @author Bart Visscher <bartv@thisnet.nl>
- * @author Brice Maron <brice@bmaron.net>
- * @author Felix Moeller <mail@felixmoeller.de>
- * @author Frank Karlitschek <frank@karlitschek.de>
- * @author Jarrett <JetUni@users.noreply.github.com>
- * @author Joas Schilling <coding@schilljs.com>
- * @author Jörn Friedrich Dreyer <jfd@butonic.de>
- * @author Kamil Domanski <kdomanski@kdemail.net>
- * @author Lukas Reschke <lukas@statuscode.ch>
- * @author Morris Jobke <hey@morrisjobke.de>
- * @author Robin McCorkell <robin@mccorkell.me.uk>
- * @author Sam Tuke <mail@samtuke.com>
- * @author Thomas Müller <thomas.mueller@tmit.eu>
- *
- * @license AGPL-3.0
- *
- * This code is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License, version 3,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License, version 3,
- * along with this program.  If not, see <http://www.gnu.org/licenses/>
- *
- */
-
-namespace OC;
-
-use OCP\Http\Client\IClientService;
-use OCP\IConfig;
-use OCP\ILogger;
-
-/**
- * Class OCSClient is a class for communication with the ownCloud appstore
- *
- * @package OC
- */
-class OCSClient {
-	/** @var IClientService */
-	private $httpClientService;
-	/** @var IConfig */
-	private $config;
-	/** @var ILogger */
-	private $logger;
-
-	/**
-	 * @param IClientService $httpClientService
-	 * @param IConfig $config
-	 * @param ILogger $logger
-	 */
-	public function __construct(IClientService $httpClientService,
-								IConfig $config,
-								ILogger $logger) {
-		$this->httpClientService = $httpClientService;
-		$this->config = $config;
-		$this->logger = $logger;
-	}
-
-	/**
-	 * Returns whether the AppStore is enabled (i.e. because the AppStore is disabled for EE)
-	 *
-	 * @return bool
-	 */
-	public function isAppStoreEnabled() {
-		return $this->config->getSystemValue('appstoreenabled', true) === true;
-	}
-
-	/**
-	 * Get the url of the OCS AppStore server.
-	 *
-	 * @return string of the AppStore server
-	 */
-	private function getAppStoreUrl() {
-		return $this->config->getSystemValue('appstoreurl', 'https://api.owncloud.com/v1');
-	}
-
-	/**
-	 * @param string $body
-	 * @param string $action
-	 * @return null|\SimpleXMLElement
-	 */
-	private function loadData($body, $action) {
-		$loadEntities = libxml_disable_entity_loader(true);
-		$data = @simplexml_load_string($body);
-		libxml_disable_entity_loader($loadEntities);
-
-		if($data === false) {
-			libxml_clear_errors();
-			$this->logger->error(
-				sprintf('Could not get %s, content was no valid XML', $action),
-				[
-					'app' => 'core',
-				]
-			);
-			return null;
-		}
-
-		return $data;
-	}
-
-	/**
-	 * Get all the categories from the OCS server
-	 *
-	 * @param array $targetVersion The target ownCloud version
-	 * @return array|null an array of category ids or null
-	 * @note returns NULL if config value appstoreenabled is set to false
-	 * This function returns a list of all the application categories on the OCS server
-	 */
-	public function getCategories(array $targetVersion) {
-		if (!$this->isAppStoreEnabled()) {
-			return null;
-		}
-
-		$client = $this->httpClientService->newClient();
-		try {
-			$response = $client->get(
-				$this->getAppStoreUrl() . '/content/categories',
-				[
-					'timeout' => 20,
-					'query' => [
-						'version' => implode('x', $targetVersion),
-					],
-				]
-			);
-		} catch(\Exception $e) {
-			$this->logger->error(
-				sprintf('Could not get categories: %s', $e->getMessage()),
-				[
-					'app' => 'core',
-				]
-			);
-			return null;
-		}
-
-		$data = $this->loadData($response->getBody(), 'categories');
-		if($data === null) {
-			return null;
-		}
-
-		$tmp = $data->data;
-		$cats = [];
-
-		foreach ($tmp->category as $value) {
-			$id = (int)$value->id;
-			$name = (string)$value->name;
-			$cats[$id] = $name;
-		}
-
-		return $cats;
-	}
-
-	/**
-	 * Get all the applications from the OCS server
-	 * @param array $categories
-	 * @param int $page
-	 * @param string $filter
-	 * @param array $targetVersion The target ownCloud version
-	 * @return array An array of application data
-	 */
-	public function getApplications(array $categories, $page, $filter, array $targetVersion) {
-		if (!$this->isAppStoreEnabled()) {
-			return [];
-		}
-
-		$client = $this->httpClientService->newClient();
-		try {
-			$response = $client->get(
-				$this->getAppStoreUrl() . '/content/data',
-				[
-					'timeout' => 20,
-					'query' => [
-						'version' => implode('x', $targetVersion),
-						'filter' => $filter,
-						'categories' => implode('x', $categories),
-						'sortmode' => 'new',
-						'page' => $page,
-						'pagesize' => 100,
-						'approved' => $filter
-					],
-				]
-			);
-		} catch(\Exception $e) {
-			$this->logger->error(
-				sprintf('Could not get applications: %s', $e->getMessage()),
-				[
-					'app' => 'core',
-				]
-			);
-			return [];
-		}
-
-		$data = $this->loadData($response->getBody(), 'applications');
-		if($data === null) {
-			return [];
-		}
-
-		$tmp = $data->data->content;
-		$tmpCount = count($tmp);
-
-		$apps = [];
-		for ($i = 0; $i < $tmpCount; $i++) {
-			$app = [];
-			$app['id'] = (string)$tmp[$i]->id;
-			$app['name'] = (string)$tmp[$i]->name;
-			$app['label'] = (string)$tmp[$i]->label;
-			$app['version'] = (string)$tmp[$i]->version;
-			$app['type'] = (string)$tmp[$i]->typeid;
-			$app['typename'] = (string)$tmp[$i]->typename;
-			$app['personid'] = (string)$tmp[$i]->personid;
-			$app['profilepage'] = (string)$tmp[$i]->profilepage;
-			$app['license'] = (string)$tmp[$i]->license;
-			$app['detailpage'] = (string)$tmp[$i]->detailpage;
-			$app['preview'] = (string)$tmp[$i]->smallpreviewpic1;
-			$app['preview-full'] = (string)$tmp[$i]->previewpic1;
-			$app['changed'] = strtotime($tmp[$i]->changed);
-			$app['description'] = (string)$tmp[$i]->description;
-			$app['score'] = (string)$tmp[$i]->score;
-			$app['downloads'] = (int)$tmp[$i]->downloads;
-			$app['level'] = (int)$tmp[$i]->approved;
-
-			$apps[] = $app;
-		}
-
-		return $apps;
-	}
-
-
-	/**
-	 * Get an the applications from the OCS server
-	 *
-	 * @param string $id
-	 * @param array $targetVersion The target ownCloud version
-	 * @return array|null an array of application data or null
-	 *
-	 * This function returns an applications from the OCS server
-	 */
-	public function getApplication($id, array $targetVersion) {
-		if (!$this->isAppStoreEnabled()) {
-			return null;
-		}
-
-		$client = $this->httpClientService->newClient();
-		try {
-			$response = $client->get(
-				$this->getAppStoreUrl() . '/content/data/' . urlencode($id),
-				[
-					'timeout' => 20,
-					'query' => [
-						'version' => implode('x', $targetVersion),
-					],
-				]
-			);
-		} catch(\Exception $e) {
-			$this->logger->error(
-				sprintf('Could not get application: %s', $e->getMessage()),
-				[
-					'app' => 'core',
-				]
-			);
-			return null;
-		}
-
-		$data = $this->loadData($response->getBody(), 'application');
-		if($data === null) {
-			return null;
-		}
-
-		$tmp = $data->data->content;
-		if (is_null($tmp)) {
-			\OCP\Util::writeLog('core', 'No update found at the ownCloud appstore for app ' . $id, \OCP\Util::DEBUG);
-			return null;
-		}
-
-		$app = [];
-		$app['id'] = (int)$id;
-		$app['name'] = (string)$tmp->name;
-		$app['version'] = (string)$tmp->version;
-		$app['type'] = (string)$tmp->typeid;
-		$app['label'] = (string)$tmp->label;
-		$app['typename'] = (string)$tmp->typename;
-		$app['personid'] = (string)$tmp->personid;
-		$app['profilepage'] = (string)$tmp->profilepage;
-		$app['detailpage'] = (string)$tmp->detailpage;
-		$app['preview1'] = (string)$tmp->smallpreviewpic1;
-		$app['preview2'] = (string)$tmp->smallpreviewpic2;
-		$app['preview3'] = (string)$tmp->smallpreviewpic3;
-		$app['changed'] = strtotime($tmp->changed);
-		$app['description'] = (string)$tmp->description;
-		$app['detailpage'] = (string)$tmp->detailpage;
-		$app['score'] = (int)$tmp->score;
-		$app['level'] = (int)$tmp->approved;
-
-		return $app;
-	}
-
-	/**
-	 * Get the download url for an application from the OCS server
-	 * @param string $id
-	 * @param array $targetVersion The target ownCloud version
-	 * @return array|null an array of application data or null
-	 */
-	public function getApplicationDownload($id, array $targetVersion) {
-		if (!$this->isAppStoreEnabled()) {
-			return null;
-		}
-		$url = $this->getAppStoreUrl() . '/content/download/' . urlencode($id) . '/1';
-		$client = $this->httpClientService->newClient();
-		try {
-			$response = $client->get(
-				$url,
-				[
-					'timeout' => 20,
-					'query' => [
-						'version' => implode('x', $targetVersion),
-					],
-				]
-			);
-		} catch(\Exception $e) {
-			$this->logger->error(
-				sprintf('Could not get application download URL: %s', $e->getMessage()),
-				[
-					'app' => 'core',
-				]
-			);
-			return null;
-		}
-
-		$data = $this->loadData($response->getBody(), 'application download URL');
-		if($data === null) {
-			return null;
-		}
-
-		$tmp = $data->data->content;
-		$app = [];
-		if (isset($tmp->downloadlink)) {
-			$app['downloadlink'] = (string)$tmp->downloadlink;
-		} else {
-			$app['downloadlink'] = '';
-		}
-		return $app;
-	}
-
-}
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 21ec311401d..3ea358498da 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
  *
  * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
  * @author Bart Visscher <bartv@thisnet.nl>
@@ -41,6 +42,8 @@
 namespace OC;
 
 use bantu\IniGetWrapper\IniGetWrapper;
+use OC\App\AppStore\Fetcher\AppFetcher;
+use OC\App\AppStore\Fetcher\CategoryFetcher;
 use OC\AppFramework\Http\Request;
 use OC\AppFramework\Db\Db;
 use OC\AppFramework\Utility\TimeFactory;
@@ -320,6 +323,21 @@ class Server extends ServerContainer implements IServerContainer {
 		$this->registerService('AppHelper', function ($c) {
 			return new \OC\AppHelper();
 		});
+		$this->registerService('AppFetcher', function ($c) {
+			return new AppFetcher(
+				$this->getAppDataDir('appstore'),
+				$this->getHTTPClientService(),
+				$this->query(TimeFactory::class),
+				$this->getConfig()
+			);
+		});
+		$this->registerService('CategoryFetcher', function ($c) {
+			return new CategoryFetcher(
+				$this->getAppDataDir('appstore'),
+				$this->getHTTPClientService(),
+				$this->query(TimeFactory::class)
+			);
+		});
 		$this->registerService('UserCache', function ($c) {
 			return new Cache\File();
 		});
@@ -580,13 +598,6 @@ class Server extends ServerContainer implements IServerContainer {
 				$c->getThemingDefaults()
 			);
 		});
-		$this->registerService('OcsClient', function (Server $c) {
-			return new OCSClient(
-				$this->getHTTPClientService(),
-				$this->getConfig(),
-				$this->getLogger()
-			);
-		});
 		$this->registerService('LDAPProvider', function(Server $c) {
 			$config = $c->getConfig();
 			$factoryClass = $config->getSystemValue('ldapProviderFactory', null);
@@ -1008,6 +1019,13 @@ class Server extends ServerContainer implements IServerContainer {
 	}
 
 	/**
+	 * @return AppFetcher
+	 */
+	public function getAppFetcher() {
+		return $this->query('AppFetcher');
+	}
+
+	/**
 	 * Returns an ICache instance. Since 8.1.0 it returns a fake cache. Use
 	 * getMemCacheFactory() instead.
 	 *
diff --git a/lib/private/Updater.php b/lib/private/Updater.php
index 646fc031a83..cd2934f7196 100644
--- a/lib/private/Updater.php
+++ b/lib/private/Updater.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
  *
  * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
  * @author Frank Karlitschek <frank@karlitschek.de>
@@ -426,11 +427,15 @@ class Updater extends BasicEmitter {
 	private function upgradeAppStoreApps(array $disabledApps) {
 		foreach($disabledApps as $app) {
 			try {
-				if (Installer::isUpdateAvailable($app)) {
-					$ocsId = \OC::$server->getConfig()->getAppValue($app, 'ocsid', '');
-
-					$this->emit('\OC\Updater', 'upgradeAppStoreApp', array($app));
-					Installer::updateAppByOCSId($ocsId);
+				$installer = new Installer(
+					\OC::$server->getAppFetcher(),
+					\OC::$server->getHTTPClientService(),
+					\OC::$server->getTempManager(),
+					$this->log
+				);
+				if (Installer::isUpdateAvailable($app, \OC::$server->getAppFetcher())) {
+					$this->emit('\OC\Updater', 'upgradeAppStoreApp', [$app]);
+					$installer->updateAppstoreApp($app);
 				}
 			} catch (\Exception $ex) {
 				$this->log->logException($ex, ['app' => 'core']);
diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index d25534aa822..a89a4650c5d 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -1,6 +1,7 @@
 <?php
 /**
  * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
  *
  * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
  * @author Bart Visscher <bartv@thisnet.nl>
@@ -326,24 +327,44 @@ class OC_App {
 	/**
 	 * enables an app
 	 *
-	 * @param mixed $app app
+	 * @param string $appId
 	 * @param array $groups (optional) when set, only these groups will have access to the app
 	 * @throws \Exception
 	 * @return void
 	 *
 	 * This function set an app as enabled in appconfig.
 	 */
-	public static function enable($app, $groups = null) {
+	public function enable($appId,
+						   $groups = null) {
 		self::$enabledAppsCache = []; // flush
-		if (!Installer::isInstalled($app)) {
-			$app = self::installApp($app);
+		$l = \OC::$server->getL10N('core');
+		$config = \OC::$server->getConfig();
+
+		// Check if app is already downloaded
+		$installer = new Installer(
+			\OC::$server->getAppFetcher(),
+			\OC::$server->getHTTPClientService(),
+			\OC::$server->getTempManager(),
+			\OC::$server->getLogger()
+		);
+		$isDownloaded = $installer->isDownloaded($appId);
+
+		if(!$isDownloaded) {
+			$installer->downloadApp($appId);
+		}
+
+		if (!Installer::isInstalled($appId)) {
+			$appId = self::installApp(
+				$appId,
+				$config,
+				$l
+			);
+			$installer->installApp($appId);
 		} else {
 			// check for required dependencies
-			$config = \OC::$server->getConfig();
-			$l = \OC::$server->getL10N('core');
-			$info = self::getAppInfo($app);
-
+			$info = self::getAppInfo($appId);
 			self::checkAppDependencies($config, $l, $info);
+			$installer->installApp($appId);
 		}
 
 		$appManager = \OC::$server->getAppManager();
@@ -356,42 +377,21 @@ class OC_App {
 					$groupsList[] = $groupManager->get($group);
 				}
 			}
-			$appManager->enableAppForGroups($app, $groupsList);
+			$appManager->enableAppForGroups($appId, $groupsList);
 		} else {
-			$appManager->enableApp($app);
+			$appManager->enableApp($appId);
 		}
 
-		$info = self::getAppInfo($app);
+		$info = self::getAppInfo($appId);
 		if(isset($info['settings']) && is_array($info['settings'])) {
-			$appPath = self::getAppPath($app);
-			self::registerAutoloading($app, $appPath);
+			$appPath = self::getAppPath($appId);
+			self::registerAutoloading($appId, $appPath);
 			\OC::$server->getSettingsManager()->setupSettings($info['settings']);
 		}
 	}
 
 	/**
 	 * @param string $app
-	 * @return int
-	 */
-	private static function downloadApp($app) {
-		$ocsClient = new OCSClient(
-			\OC::$server->getHTTPClientService(),
-			\OC::$server->getConfig(),
-			\OC::$server->getLogger()
-		);
-		$appData = $ocsClient->getApplication($app, \OCP\Util::getVersion());
-		$download = $ocsClient->getApplicationDownload($app, \OCP\Util::getVersion());
-		if(isset($download['downloadlink']) and $download['downloadlink']!='') {
-			// Replace spaces in download link without encoding entire URL
-			$download['downloadlink'] = str_replace(' ', '%20', $download['downloadlink']);
-			$info = array('source' => 'http', 'href' => $download['downloadlink'], 'appdata' => $appData);
-			$app = Installer::installApp($info);
-		}
-		return $app;
-	}
-
-	/**
-	 * @param string $app
 	 * @return bool
 	 */
 	public static function removeApp($app) {
@@ -399,7 +399,13 @@ class OC_App {
 			return false;
 		}
 
-		return Installer::removeApp($app);
+		$installer = new Installer(
+			\OC::$server->getAppFetcher(),
+			\OC::$server->getHTTPClientService(),
+			\OC::$server->getTempManager(),
+			\OC::$server->getLogger()
+		);
+		return $installer->removeApp($app);
 	}
 
 	/**
@@ -409,11 +415,6 @@ class OC_App {
 	 * @throws Exception
 	 */
 	public static function disable($app) {
-		// Convert OCS ID to regular application identifier
-		if(self::getInternalAppIdByOcs($app) !== false) {
-			$app = self::getInternalAppIdByOcs($app);
-		}
-
 		// flush
 		self::$enabledAppsCache = array();
 
@@ -554,7 +555,7 @@ class OC_App {
 	 * @param string $appId
 	 * @return false|string
 	 */
-	protected static function findAppInDirectories($appId) {
+	public static function findAppInDirectories($appId) {
 		$sanitizedAppId = self::cleanAppId($appId);
 		if($sanitizedAppId !== $appId) {
 			return false;
@@ -613,18 +614,6 @@ class OC_App {
 		return false;
 	}
 
-
-	/**
-	 * check if an app's directory is writable
-	 *
-	 * @param string $appId
-	 * @return bool
-	 */
-	public static function isAppDirWritable($appId) {
-		$path = self::getAppPath($appId);
-		return ($path !== false) ? is_writable($path) : false;
-	}
-
 	/**
 	 * Get the path for the given app on the access
 	 * If the app is defined in multiple directories, the first one is taken. (false if not found)
@@ -837,20 +826,11 @@ class OC_App {
 	/**
 	 * List all apps, this is used in apps.php
 	 *
-	 * @param bool $onlyLocal
-	 * @param bool $includeUpdateInfo Should we check whether there is an update
-	 *                                in the app store?
-	 * @param OCSClient $ocsClient
 	 * @return array
 	 */
-	public static function listAllApps($onlyLocal = false,
-									   $includeUpdateInfo = true,
-									   OCSClient $ocsClient) {
+	public function listAllApps() {
 		$installedApps = OC_App::getAllApps();
 
-		//TODO which apps do we want to blacklist and how do we integrate
-		// blacklisting with the multi apps folder feature?
-
 		//we don't want to show configuration for these
 		$blacklist = \OC::$server->getAppManager()->getAlwaysEnabledApps();
 		$appList = array();
@@ -893,8 +873,6 @@ class OC_App {
 					$info['removable'] = true;
 				}
 
-				$info['update'] = ($includeUpdateInfo) ? Installer::isUpdateAvailable($app) : null;
-
 				$appPath = self::getAppPath($app);
 				if($appPath !== false) {
 					$appIcon = $appPath . '/img/' . $app . '.svg';
@@ -926,29 +904,8 @@ class OC_App {
 				$appList[] = $info;
 			}
 		}
-		if ($onlyLocal) {
-			$remoteApps = [];
-		} else {
-			$remoteApps = OC_App::getAppstoreApps('approved', null, $ocsClient);
-		}
-		if ($remoteApps) {
-			// Remove duplicates
-			foreach ($appList as $app) {
-				foreach ($remoteApps AS $key => $remote) {
-					if ($app['name'] === $remote['name'] ||
-						(isset($app['ocsid']) &&
-							$app['ocsid'] === $remote['id'])
-					) {
-						unset($remoteApps[$key]);
-					}
-				}
-			}
-			$combinedApps = array_merge($appList, $remoteApps);
-		} else {
-			$combinedApps = $appList;
-		}
 
-		return $combinedApps;
+		return $appList;
 	}
 
 	/**
@@ -966,70 +923,6 @@ class OC_App {
 		return false;
 	}
 
-	/**
-	 * Get a list of all apps on the appstore
-	 * @param string $filter
-	 * @param string|null $category
-	 * @param OCSClient $ocsClient
-	 * @return array|bool  multi-dimensional array of apps.
-	 *                     Keys: id, name, type, typename, personid, license, detailpage, preview, changed, description
-	 */
-	public static function getAppstoreApps($filter = 'approved',
-										   $category = null,
-										   OCSClient $ocsClient) {
-		$categories = [$category];
-
-		if (is_null($category)) {
-			$categoryNames = $ocsClient->getCategories(\OCP\Util::getVersion());
-			if (is_array($categoryNames)) {
-				// Check that categories of apps were retrieved correctly
-				if (!$categories = array_keys($categoryNames)) {
-					return false;
-				}
-			} else {
-				return false;
-			}
-		}
-
-		$page = 0;
-		$remoteApps = $ocsClient->getApplications($categories, $page, $filter, \OCP\Util::getVersion());
-		$apps = [];
-		$i = 0;
-		$l = \OC::$server->getL10N('core');
-		foreach ($remoteApps as $app) {
-			$potentialCleanId = self::getInternalAppIdByOcs($app['id']);
-			// enhance app info (for example the description)
-			$apps[$i] = OC_App::parseAppInfo($app);
-			$apps[$i]['author'] = $app['personid'];
-			$apps[$i]['ocs_id'] = $app['id'];
-			$apps[$i]['internal'] = 0;
-			$apps[$i]['active'] = ($potentialCleanId !== false) ? self::isEnabled($potentialCleanId) : false;
-			$apps[$i]['update'] = false;
-			$apps[$i]['groups'] = false;
-			$apps[$i]['score'] = $app['score'];
-			$apps[$i]['removable'] = false;
-			if ($app['label'] == 'recommended') {
-				$apps[$i]['internallabel'] = (string)$l->t('Recommended');
-				$apps[$i]['internalclass'] = 'recommendedapp';
-			}
-
-			// Apps from the appstore are always assumed to be compatible with the
-			// the current release as the initial filtering is done on the appstore
-			$apps[$i]['dependencies']['owncloud']['@attributes']['min-version'] = implode('.', \OCP\Util::getVersion());
-			$apps[$i]['dependencies']['owncloud']['@attributes']['max-version'] = implode('.', \OCP\Util::getVersion());
-
-			$i++;
-		}
-
-
-
-		if (empty($apps)) {
-			return false;
-		} else {
-			return $apps;
-		}
-	}
-
 	public static function shouldUpgrade($app) {
 		$versions = self::getAppVersions();
 		$currentVersion = OC_App::getAppVersion($app);
@@ -1083,7 +976,9 @@ class OC_App {
 	public static function isAppCompatible($ocVersion, $appInfo) {
 		$requireMin = '';
 		$requireMax = '';
-		if (isset($appInfo['dependencies']['owncloud']['@attributes']['min-version'])) {
+		if (isset($appInfo['dependencies']['nextcloud']['@attributes']['min-version'])) {
+			$requireMin = $appInfo['dependencies']['nextcloud']['@attributes']['min-version'];
+		} elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['min-version'])) {
 			$requireMin = $appInfo['dependencies']['owncloud']['@attributes']['min-version'];
 		} else if (isset($appInfo['requiremin'])) {
 			$requireMin = $appInfo['requiremin'];
@@ -1091,7 +986,9 @@ class OC_App {
 			$requireMin = $appInfo['require'];
 		}
 
-		if (isset($appInfo['dependencies']['owncloud']['@attributes']['max-version'])) {
+		if (isset($appInfo['dependencies']['nextcloud']['@attributes']['max-version'])) {
+			$requireMax = $appInfo['dependencies']['nextcloud']['@attributes']['max-version'];
+		} elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['max-version'])) {
 			$requireMax = $appInfo['dependencies']['owncloud']['@attributes']['max-version'];
 		} else if (isset($appInfo['requiremax'])) {
 			$requireMax = $appInfo['requiremax'];
@@ -1132,46 +1029,16 @@ class OC_App {
 
 	/**
 	 * @param string $app
+	 * @param \OCP\IConfig $config
+	 * @param \OCP\IL10N $l
 	 * @return bool
+	 *
 	 * @throws Exception if app is not compatible with this version of ownCloud
 	 * @throws Exception if no app-name was specified
 	 */
-	public static function installApp($app) {
-		$appName = $app; // $app will be overwritten, preserve name for error logging
-		$l = \OC::$server->getL10N('core');
-		$config = \OC::$server->getConfig();
-		$ocsClient = new OCSClient(
-			\OC::$server->getHTTPClientService(),
-			$config,
-			\OC::$server->getLogger()
-		);
-		$appData = $ocsClient->getApplication($app, \OCP\Util::getVersion());
-
-		// check if app is a shipped app or not. OCS apps have an integer as id, shipped apps use a string
-		if (!is_numeric($app)) {
-			$shippedVersion = self::getAppVersion($app);
-			if ($appData && version_compare($shippedVersion, $appData['version'], '<')) {
-				$app = self::downloadApp($app);
-			} else {
-				$app = Installer::installShippedApp($app);
-			}
-		} else {
-			// Maybe the app is already installed - compare the version in this
-			// case and use the local already installed one.
-			// FIXME: This is a horrible hack. I feel sad. The god of code cleanness may forgive me.
-			$internalAppId = self::getInternalAppIdByOcs($app);
-			if($internalAppId !== false) {
-				if($appData && version_compare(\OC_App::getAppVersion($internalAppId), $appData['version'], '<')) {
-					$app = self::downloadApp($app);
-				} else {
-					self::enable($internalAppId);
-					$app = $internalAppId;
-				}
-			} else {
-				$app = self::downloadApp($app);
-			}
-		}
-
+	public function installApp($app,
+							   \OCP\IConfig $config,
+							   \OCP\IL10N $l) {
 		if ($app !== false) {
 			// check if the app is compatible with this version of ownCloud
 			$info = self::getAppInfo($app);
diff --git a/lib/private/legacy/util.php b/lib/private/legacy/util.php
index e4c2caeafd7..5cd92eaa415 100644
--- a/lib/private/legacy/util.php
+++ b/lib/private/legacy/util.php
@@ -757,6 +757,7 @@ class OC_Util {
 				'simplexml_load_string' => 'SimpleXML',
 				'hash' => 'HASH Message Digest Framework',
 				'curl_init' => 'cURL',
+				'openssl_verify' => 'OpenSSL',
 			],
 			'defined' => array(
 				'PDO::ATTR_DRIVER_NAME' => 'PDO'