<?php

/**
* ownCloud
*
* @author Frank Karlitschek
* @author Michael Gapczynski
* @copyright 2012 Frank Karlitschek frank@owncloud.org
* @copyright 2012 Michael Gapczynski mtgap@owncloud.com
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
*
*/


/**
 * Class to handle open collaboration services API requests
 *
 */
class OC_OCS {

	/**
	* reads input date from get/post/cookies and converts the date to a special data-type
	*
	* @param string HTTP method to read the key from
	* @param string Parameter to read
	* @param string Variable type to format data
	* @param mixed Default value to return if the key is not found
	* @return mixed Data or if the key is not found and no default is set it will exit with a 400 Bad request
	*/
	public static function readData($method, $key, $type = 'raw', $default = null) {
		if ($method == 'get') {
			if (isset($_GET[$key])) {
				$data = $_GET[$key];
			} else if (isset($default)) {
				return $default;
			} else {
				$data = false;
			}
		} else if ($method == 'post') {
			if (isset($_POST[$key])) {
				$data = $_POST[$key];
			} else if (isset($default)) {
				return $default;
			} else {
				$data = false;
			}
		}
		if ($data === false) {
			echo self::generateXml('', 'fail', 400, 'Bad request. Please provide a valid '.$key);
			exit();
		} else {
			// NOTE: Is the raw type necessary? It might be a little risky without sanitization
			if ($type == 'raw') return $data;
			elseif ($type == 'text') return OC_Util::sanitizeHTML($data);
			elseif ($type == 'int')  return (int) $data;
			elseif ($type == 'float') return (float) $data;
			elseif ($type == 'array') return OC_Util::sanitizeHTML($data);
			else return OC_Util::sanitizeHTML($data);
		}
	}

	/**
	main function to handle the REST request
	**/
	public static function handle() {
		// overwrite the 404 error page returncode
		header("HTTP/1.0 200 OK");


		if($_SERVER['REQUEST_METHOD'] == 'GET') {
			$method='get';
		}elseif($_SERVER['REQUEST_METHOD'] == 'PUT') {
			$method='put';
			parse_str(file_get_contents("php://input"),$put_vars);
		}elseif($_SERVER['REQUEST_METHOD'] == 'POST') {
			$method='post';
		}else{
			echo('internal server error: method not supported');
			exit();
		}

		// preprocess url
		$url = $_SERVER['REQUEST_URI'];
		if(substr($url,(strlen($url)-1))<>'/') $url.='/';
		$ex=explode('/',$url);
		$paracount=count($ex);
		$format = self::readData($method, 'format', 'text', '');

		// eventhandler
		// CONFIG
		// apiconfig - GET - CONFIG
		if(($method=='get') and ($ex[$paracount-3] == 'v1.php') and ($ex[$paracount-2] == 'config')){
			OC_OCS::apiconfig($format);

		// PERSON
		// personcheck - POST - PERSON/CHECK
		}elseif(($method=='post') and ($ex[$paracount-4] == 'v1.php') and ($ex[$paracount-3]=='person') and ($ex[$paracount-2] == 'check')){
			$login = self::readData($method, 'login', 'text');
			$passwd = self::readData($method, 'password', 'text');
			OC_OCS::personcheck($format,$login,$passwd);

		// ACTIVITY
		// activityget - GET ACTIVITY   page,pagesize als urlparameter
		}elseif(($method=='get') and ($ex[$paracount-3] == 'v1.php') and ($ex[$paracount-2] == 'activity')){
			$page = self::readData($method, 'page', 'int', 0);
			$pagesize = self::readData($method, 'pagesize','int', 10);
			if($pagesize<1 or $pagesize>100) $pagesize=10;
			OC_OCS::activityget($format,$page,$pagesize);

		// activityput - POST ACTIVITY
		}elseif(($method=='post') and ($ex[$paracount-3] == 'v1.php') and ($ex[$paracount-2] == 'activity')){
			$message = self::readData($method, 'message', 'text');
			OC_OCS::activityput($format,$message);


		// PRIVATEDATA
		// get - GET DATA
		}elseif(($method=='get') and ($ex[$paracount-4] == 'v1.php') and ($ex[$paracount-2] == 'getattribute')){
			OC_OCS::privateDataGet($format);

		}elseif(($method=='get') and ($ex[$paracount-5] == 'v1.php') and ($ex[$paracount-3] == 'getattribute')){
			$app=$ex[$paracount-2];
			OC_OCS::privateDataGet($format, $app);
		}elseif(($method=='get') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-4] == 'getattribute')){

			$key=$ex[$paracount-2];
			$app=$ex[$paracount-3];
			OC_OCS::privateDataGet($format, $app,$key);

		// set - POST DATA
		}elseif(($method=='post') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-4] == 'setattribute')){
			$key=$ex[$paracount-2];
			$app=$ex[$paracount-3];
			$value = self::readData($method, 'value', 'text');
			OC_OCS::privatedataset($format, $app, $key, $value);
		// delete - POST DATA
		}elseif(($method=='post') and ($ex[$paracount-6] =='v1.php') and ($ex[$paracount-4] == 'deleteattribute')){
			$key=$ex[$paracount-2];
			$app=$ex[$paracount-3];
			OC_OCS::privatedatadelete($format, $app, $key);

		// CLOUD
		// systemWebApps 
		}elseif(($method=='get') and ($ex[$paracount-5] == 'v1.php') and ($ex[$paracount-4]=='cloud') and ($ex[$paracount-3] == 'system') and ($ex[$paracount-2] == 'webapps')){
			OC_OCS::systemwebapps($format);

		// quotaget 
		}elseif(($method=='get') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'quota')){
			$user=$ex[$paracount-3];
			OC_OCS::quotaget($format,$user);

		// quotaset 
		}elseif(($method=='post') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'quota')){
			$user=$ex[$paracount-3];
			$quota = self::readData('post', 'quota', 'int');
			OC_OCS::quotaset($format,$user,$quota);

		// keygetpublic 
		}elseif(($method=='get') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'publickey')){
			$user=$ex[$paracount-3];
			OC_OCS::publicKeyGet($format,$user);

		//keysetpublic
		}elseif(($method=='post') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'publickey')){
				$user=$ex[$paracount-3];
				$key = self::readData('post', 'key', 'string');
				OC_OCS::publicKeySet($format,$user, $key);
		
		// keygetprivate 
		}elseif(($method=='get') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'privatekey')){
			$user=$ex[$paracount-3];
			OC_OCS::privateKeyGet($format,$user);
		
		//keysetprivate
		}elseif(($method=='post') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'privatekey')){
				$user=$ex[$paracount-3];
				$key = self::readData('post', 'key', 'string');
				OC_OCS::privateKeySet($format,$user, $key);
				
		// keygetfiles
		}elseif(($method=='get') and ($ex[$paracount-7] == 'v1.php') and ($ex[$paracount-6]=='cloud') and ($ex[$paracount-5] == 'user') and ($ex[$paracount-3] == 'filekey')){
			$user=$ex[$paracount-4];
			$file = urldecode($ex[$paracount-2]);
			OC_OCS::fileKeyGet($format,$user, $file);
		
		//keysetfiles
		}elseif(($method=='post') and ($ex[$paracount-6] == 'v1.php') and ($ex[$paracount-5]=='cloud') and ($ex[$paracount-4] == 'user') and ($ex[$paracount-2] == 'filekey')){
			$user=$ex[$paracount-3];
			$key = self::readData('post', 'key', 'string');
			$file = self::readData('post', 'file', 'string');
			OC_OCS::fileKeySet($format,$user, $file, $key);

// add more calls here
// please document all the call in the draft spec
// http://www.freedesktop.org/wiki/Specifications/open-collaboration-services-1.7#CLOUD

// TODO:
// users
// groups
// bookmarks
// sharing
// versioning
// news (rss)


		}else{
			$txt='Invalid query, please check the syntax. API specifications are here: http://www.freedesktop.org/wiki/Specifications/open-collaboration-services. DEBUG OUTPUT:'."\n";
			$txt.=OC_OCS::getdebugoutput();
			echo(OC_OCS::generatexml($format,'failed',999,$txt));
		}
		exit();
	}

	/**
	* generated some debug information to make it easier to find faild API calls
	* @return debug data string
	*/
	private static function getDebugOutput() {
		$txt='';
		$txt.="debug output:\n";
		if(isset($_SERVER['REQUEST_METHOD'])) $txt.='http request method: '.$_SERVER['REQUEST_METHOD']."\n";
		if(isset($_SERVER['REQUEST_URI'])) $txt.='http request uri: '.$_SERVER['REQUEST_URI']."\n";
		if(isset($_GET)) foreach($_GET as $key=>$value) $txt.='get parameter: '.$key.'->'.$value."\n";
		if(isset($_POST)) foreach($_POST as $key=>$value) $txt.='post parameter: '.$key.'->'.$value."\n";
		return($txt);
	}

	/**
	* checks if the user is authenticated
	* checks the IP whitlist, apikeys and login/password combination
	* if $forceuser is true and the authentication failed it returns an 401 http response.
	* if $forceuser is false and authentification fails it returns an empty username string
	* @param bool $forceuser
	* @return username string
	*/
	private static function checkPassword($forceuser=true) {
		//valid user account ?
		if(isset($_SERVER['PHP_AUTH_USER'])) $authuser=$_SERVER['PHP_AUTH_USER']; else $authuser='';
		if(isset($_SERVER['PHP_AUTH_PW']))   $authpw=$_SERVER['PHP_AUTH_PW']; else $authpw='';

		if(empty($authuser)) {
			if($forceuser){
				header('WWW-Authenticate: Basic realm="your valid user account or api key"');
				header('HTTP/1.0 401 Unauthorized');
				exit;
			}else{
				$identifieduser='';
			}
		}else{
			if(!OC_User::login($authuser,$authpw)){
				if($forceuser){
					header('WWW-Authenticate: Basic realm="your valid user account or api key"');
					header('HTTP/1.0 401 Unauthorized');
					exit;
				}else{
					$identifieduser='';
				}
			}else{
				$identifieduser=$authuser;
			}
		}

		return($identifieduser);
	}


	/**
	* generates the xml or json response for the API call from an multidimenional data array.
	* @param string $format
	* @param string $status
	* @param string $statuscode
	* @param string $message
	* @param array $data
	* @param string $tag
	* @param string $tagattribute
	* @param int $dimension
	* @param int $itemscount
	* @param int $itemsperpage
	* @return string xml/json
	*/
	private static function generateXml($format,$status,$statuscode,$message,$data=array(),$tag='',$tagattribute='',$dimension=-1,$itemscount='',$itemsperpage='') {
		if($format=='json') {
			$json=array();
			$json['status']=$status;
			$json['statuscode']=$statuscode;
			$json['message']=$message;
			$json['totalitems']=$itemscount;
			$json['itemsperpage']=$itemsperpage;
			$json['data']=$data;
			return(json_encode($json));
		}else{
			$txt='';
			$writer = xmlwriter_open_memory();
			xmlwriter_set_indent( $writer, 2 );
			xmlwriter_start_document($writer );
			xmlwriter_start_element($writer,'ocs');
			xmlwriter_start_element($writer,'meta');
			xmlwriter_write_element($writer,'status',$status);
			xmlwriter_write_element($writer,'statuscode',$statuscode);
			xmlwriter_write_element($writer,'message',$message);
			if($itemscount<>'') xmlwriter_write_element($writer,'totalitems',$itemscount);
			if(!empty($itemsperpage)) xmlwriter_write_element($writer,'itemsperpage',$itemsperpage);
			xmlwriter_end_element($writer);
			if($dimension=='0') {
				// 0 dimensions
				xmlwriter_write_element($writer,'data',$data);

			}elseif($dimension=='1') {
				xmlwriter_start_element($writer,'data');
				foreach($data as $key=>$entry) {
				xmlwriter_write_element($writer,$key,$entry);
				}
				xmlwriter_end_element($writer);

			}elseif($dimension=='2') {
				xmlwriter_start_element($writer,'data');
				foreach($data as $entry) {
				xmlwriter_start_element($writer,$tag);
				if(!empty($tagattribute)) {
				xmlwriter_write_attribute($writer,'details',$tagattribute);
				}
				foreach($entry as $key=>$value) {
				if(is_array($value)){
				foreach($value as $k=>$v) {
					xmlwriter_write_element($writer,$k,$v);
				}
				} else {
				xmlwriter_write_element($writer,$key,$value);
				}
				}
				xmlwriter_end_element($writer);
				}
				xmlwriter_end_element($writer);

			}elseif($dimension=='3') {
				xmlwriter_start_element($writer,'data');
				foreach($data as $entrykey=>$entry) {
				xmlwriter_start_element($writer,$tag);
				if(!empty($tagattribute)) {
				xmlwriter_write_attribute($writer,'details',$tagattribute);
				}
				foreach($entry as $key=>$value) {
				if(is_array($value)){
				xmlwriter_start_element($writer,$entrykey);
				foreach($value as $k=>$v) {
					xmlwriter_write_element($writer,$k,$v);
				}
				xmlwriter_end_element($writer);
				} else {
				xmlwriter_write_element($writer,$key,$value);
				}
				}
				xmlwriter_end_element($writer);
				}
				xmlwriter_end_element($writer);
			}elseif($dimension=='dynamic') {
				xmlwriter_start_element($writer,'data');
				OC_OCS::toxml($writer,$data,'comment');
				xmlwriter_end_element($writer);
			}

			xmlwriter_end_element($writer);

			xmlwriter_end_document( $writer );
			$txt.=xmlwriter_output_memory( $writer );
			unset($writer);
			return($txt);
		}
	}

	public static function toXml($writer,$data,$node) {
		foreach($data as $key => $value) {
			if (is_numeric($key)) {
				$key = $node;
			}
			if (is_array($value)){
				xmlwriter_start_element($writer,$key);
				OC_OCS::toxml($writer,$value,$node);
				xmlwriter_end_element($writer);
			}else{
				xmlwriter_write_element($writer,$key,$value);
			}
		}
	}


	/**
	* return the config data of this server
	* @param string $format
	* @return string xml/json
	*/
	private static function apiConfig($format) {
		$user=OC_OCS::checkpassword(false);
		$url=substr(OCP\Util::getServerHost().$_SERVER['SCRIPT_NAME'],0,-11).'';

		$xml['version']='1.7';
		$xml['website']='ownCloud';
		$xml['host']=OCP\Util::getServerHost();
		$xml['contact']='';
		$xml['ssl']='false';
		echo(OC_OCS::generatexml($format,'ok',100,'',$xml,'config','',1));
	}


	/**
	* check if the provided login/apikey/password is valid
	* @param string $format
	* @param string $login
	* @param string $passwd
	* @return string xml/json
	*/
	private static function personCheck($format,$login,$passwd) {
		if($login<>''){
			if(OC_User::login($login,$passwd)){
				$xml['person']['personid']=$login;
				echo(OC_OCS::generatexml($format,'ok',100,'',$xml,'person','check',2));
			}else{
				echo(OC_OCS::generatexml($format,'failed',102,'login not valid'));
			}
		}else{
			echo(OC_OCS::generatexml($format,'failed',101,'please specify all mandatory fields'));
		}
	}


	// ACTIVITY API #############################################

	/**
	* get my activities
	* @param string $format
	* @param string $page
	* @param string $pagesize
	* @return string xml/json
	*/
	private static function activityGet($format,$page,$pagesize) {
		$user=OC_OCS::checkpassword();

			//TODO

		$txt=OC_OCS::generatexml($format,'ok',100,'',$xml,'activity','full',2,$totalcount,$pagesize);
		echo($txt);
	}

	/**
	* submit a activity
	* @param string $format
	* @param string $message
	* @return string xml/json
	*/
	private static function activityPut($format,$message) {
		// not implemented in ownCloud
		$user=OC_OCS::checkpassword();
		echo(OC_OCS::generatexml($format,'ok',100,''));
	}

	// PRIVATEDATA API #############################################

	/**
	* get private data and create the xml for ocs
	* @param string $format
	* @param string $app
	* @param string $key
	* @return string xml/json
	*/
	private static function privateDataGet($format,$app="",$key="") {
		$user=OC_OCS::checkpassword();
		$result=OC_OCS::getData($user,$app,$key);
		$xml=array();
		foreach($result as $i=>$log) {
			$xml[$i]['key']=$log['key'];
			$xml[$i]['app']=$log['app'];
			$xml[$i]['value']=$log['value'];
		}


		$txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'privatedata', 'full', 2, count($xml), 0);//TODO: replace 'privatedata' with 'attribute' once a new libattice has been released that works with it
		echo($txt);
	}

	/**
	* set private data referenced by $key to $value and generate the xml for ocs
	* @param string $format
	* @param string $app
	* @param string $key
	* @param string $value
	* @return string xml/json
	*/
	private static function privateDataSet($format, $app, $key, $value) {
		$user=OC_OCS::checkpassword();
		if(OC_OCS::setData($user,$app,$key,$value)){
			echo(OC_OCS::generatexml($format,'ok',100,''));
		}
	}

	/**
	* delete private data referenced by $key and generate the xml for ocs
	* @param string $format
	* @param string $app
	* @param string $key
	* @return string xml/json
	*/
	private static function privateDataDelete($format, $app, $key) {
		if($key=="" or $app==""){
			return; //key and app are NOT optional here
		}
		$user=OC_OCS::checkpassword();
		if(OC_OCS::deleteData($user,$app,$key)){
			echo(OC_OCS::generatexml($format,'ok',100,''));
		}
	}
	
	/**
	* get private data
	* @param string $user
	* @param string $app
	* @param string $key
	* @param bool $like use LIKE instead of = when comparing keys
	* @return array
	*/
	public static function getData($user,$app="",$key="") {
		if($app){
			$apps=array($app);
		}else{
			$apps=OC_Preferences::getApps($user);
		}
		if($key){
			$keys=array($key);
		}else{
			foreach($apps as $app){
				$keys=OC_Preferences::getKeys($user,$app);
			}
		}
		$result=array();
		foreach($apps as $app){
			foreach($keys as $key){
				$value=OC_Preferences::getValue($user,$app,$key);
				$result[]=array('app'=>$app,'key'=>$key,'value'=>$value);
			}
		}
		return $result;
	}

	/**
	* set private data referenced by $key to $value
	* @param string $user
	* @param string $app
	* @param string $key
	* @param string $value
	* @return bool
	*/
	public static function setData($user, $app, $key, $value) {
		return OC_Preferences::setValue($user,$app,$key,$value);
	}

	/**
	* delete private data referenced by $key
	* @param string $user
	* @param string $app
	* @param string $key
	* @return string xml/json
	*/
	public static function deleteData($user, $app, $key) {
		return OC_Preferences::deleteKey($user,$app,$key);
	}


        // CLOUD API #############################################

        /**
        * get a list of installed web apps
        * @param string $format
        * @return string xml/json
        */
        private static function systemWebApps($format) {
                $login=OC_OCS::checkpassword();
		$apps=OC_App::getEnabledApps();
		$values=array();
		foreach($apps as $app) {
			$info=OC_App::getAppInfo($app);
			if(isset($info['standalone'])) {
				$newvalue=array('name'=>$info['name'],'url'=>OC_Helper::linkToAbsolute($app,''),'icon'=>'');
				$values[]=$newvalue;
			}

		}
		$txt=OC_OCS::generatexml($format, 'ok', 100, '', $values, 'cloud', '', 2, 0, 0);
		echo($txt);

        }


        /**
        * get the quota of a user
        * @param string $format
        * @param string $user
        * @return string xml/json
        */
        private static function quotaGet($format,$user) {
                $login=OC_OCS::checkpassword();
		if(OC_Group::inGroup($login, 'admin') or ($login==$user)) {

			if(OC_User::userExists($user)){
				// calculate the disc space
				$user_dir = '/'.$user.'/files';
				OC_Filesystem::init($user_dir);
				$rootInfo=OC_FileCache::get('');
				$sharedInfo=OC_FileCache::get('/Shared');
				$used=$rootInfo['size']-$sharedInfo['size'];
				$free=OC_Filesystem::free_space();
				$total=$free+$used;
				if($total==0) $total=1;  // prevent division by zero
				$relative=round(($used/$total)*10000)/100;

				$xml=array();
				$xml['quota']=$total;
				$xml['free']=$free;
				$xml['used']=$used;
				$xml['relative']=$relative;

				$txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'cloud', '', 1, 0, 0);
				echo($txt);
			}else{
				echo self::generateXml('', 'fail', 300, 'User does not exist');
			}
		}else{
			echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
		}
        }

        /**
        * set the quota of a user
        * @param string $format
        * @param string $user
        * @param string $quota
        * @return string xml/json
        */
        private static function quotaSet($format,$user,$quota) {
                $login=OC_OCS::checkpassword();
                if(OC_Group::inGroup($login, 'admin')) {

			// todo
			// not yet implemented
			// add logic here
			error_log('OCS call: user:'.$user.' quota:'.$quota);

                        $xml=array();
                        $txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'cloud', '', 1, 0, 0);
                        echo($txt);
                }else{
                        echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
                }
        }

        /**
        * get the public key of a user
        * @param string $format
        * @param string $user
        * @return string xml/json
        */
        private static function publicKeyGet($format, $user) {
        	$login=OC_OCS::checkpassword();
        	if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
        		if(OC_User::userExists($user)){
        			if (($key = OCA_Encryption\Keymanager::getPublicKey($user))) {
        				$xml=array();
        				$xml['key'] = $key;
        				$txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'cloud', '', 1, 0, 0);
        				echo($txt);
        			}
        			else {
        				echo self::generateXml('', 'fail', 404, 'public key does not exist');
        			}
        		} else {
        			echo self::generateXml('', 'fail', 300, 'User does not exist');
        		}
        	} else {
        		echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
        	}
        }

        /**
         * set the public key of a user
         * @param string $format
         * @param string $user
         * @param string $key
         * @return string xml/json
         */
        private static function publicKeySet($format, $user, $key) {
        	$login=OC_OCS::checkpassword();
        	if(($login==$user)) {
        		if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
        			if (($key = OCA_Encryption\Keymanager::setPublicKey($user, $key))) {
        				echo self::generateXml('', 'ok', 100, '');
        			} else {
        				echo self::generateXml('', 'fail', 404, 'could not add your public key to the key storage');
        			}
        		} else {
        			echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
        		}
        	}else{
        		echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
        	}
        }
        	
        /**
        * get the private key of a user
        * @param string $format
        * @param string $user
        * @return string xml/json
        */
        private static function privateKeyGet($format, $user) {
        	$login=OC_OCS::checkpassword();
        	if(($login==$user)) {
        		if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
        			if (($key = OCA_Encryption\Keymanager::getPrivateKey($user))) {
        				$xml=array();
        				$xml['key']=$key;
        				$txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'cloud', '', 1, 0, 0);
        				echo($txt);
        			} else {
        				echo self::generateXml('', 'fail', 404, 'private key does not exist');
        			}
        		} else {
        			echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
        		}
        	}else{
        		echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
        	}
        }
		
		/**
		 * set the private key of a user
		 * @param string $format
		 * @param string $user
		 * @param string $key
		 * @return string xml/json
		 */
        private static function privateKeySet($format, $user, $key) {
        	$login=OC_OCS::checkpassword();
        	if(($login==$user)) {
        		if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
        			if (($key = OCA_Encryption\Keymanager::setPrivateKey($user, $key))) {
        				echo self::generateXml('', 'ok', 100, '');
        			} else {
        				echo self::generateXml('', 'fail', 404, 'could not add your private key to the key storage');
        			}
        		} else {
        			echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
        		}
        	}else{
        		echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
        	}
        }

		/**
		 * get the encryption key of a file
		 * @param string $format
		 * @param string $user
		 * @param string $file
		 * @return string xml/json
		 */
		private static function fileKeyGet($format, $user, $file) {
			$login=OC_OCS::checkpassword();
			if(($login==$user)) {
				if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
					if (($key = OCA_Encryption\Keymanager::getFileKey($user, $file))) {
						$xml=array();
						$xml['key']=$key;
						$txt=OC_OCS::generatexml($format, 'ok', 100, '', $xml, 'cloud', '', 1, 0, 0);
						echo($txt);
					} else {
						echo self::generateXml('', 'fail', 404, 'file key does not exist');
					}
				} else {
					echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
				}
			}else{
				echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
			}
		}
		
		/**
		 * set the encryption keyn of a file
		 * @param string $format
		 * @param string $user
		 * @param string $file
		 * @param string $key
		 * @return string xml/json
		 */
		private static function fileKeySet($format, $user, $file, $key) {
			$login=OC_OCS::checkpassword();
			if(($login==$user)) {
				if(OC_App::isEnabled('files_encryption') && OCA_Encryption\Crypt::mode($user) === 'client') {
					if (($key = OCA_Encryption\Keymanager::setFileKey($user, $file, $key))) {
						echo self::generateXml('', 'ok', 100, '');
						return true;
					} else {
						echo self::generateXml('', 'fail', 404, 'could not write key file');
					}
				} else {
					echo self::generateXml('', 'fail', 300, 'Client side encryption not enabled for user ' . $user);
				}
			}else{
				echo self::generateXml('', 'fail', 300, 'You don´t have permission to access this ressource.');
			}
			return false;
		}

}