OCS API for server-to-server sharing

2 files changed, 823 insertions, 0 deletions

diff --git a/apps/files_sharing/api/local.php b/apps/files_sharing/api/local.php
new file mode 100644
index 00000000000..d9291c29f61
--- /dev/null
+++ b/apps/files_sharing/api/local.php
@@ -0,0 +1,599 @@
+<?php
+/**
+ * ownCloud - OCS API for local shares
+ *
+ * @author Bjoern Schiessle
+ * @copyright 2013 Bjoern Schiessle schiessle@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/>.
+ *
+ */
+
+namespace OCA\Files_Sharing\API;
+
+class Local {
+
+	/**
+	 * get all shares
+	 *
+	 * @param array $params option 'file' to limit the result to a specific file/folder
+	 * @return \OC_OCS_Result share information
+	 */
+	public static function getAllShares($params) {
+		if (isset($_GET['shared_with_me']) && $_GET['shared_with_me'] !== 'false') {
+				return self::getFilesSharedWithMe();
+			}
+		// if a file is specified, get the share for this file
+		if (isset($_GET['path'])) {
+			$params['itemSource'] = self::getFileId($_GET['path']);
+			$params['path'] = $_GET['path'];
+			$params['itemType'] = self::getItemType($_GET['path']);
+
+			if ( isset($_GET['reshares']) && $_GET['reshares'] !== 'false' ) {
+				$params['reshares'] = true;
+			} else {
+				$params['reshares'] = false;
+			}
+
+			if (isset($_GET['subfiles']) && $_GET['subfiles'] !== 'false') {
+				return self::getSharesFromFolder($params);
+			}
+			return self::collectShares($params);
+		}
+
+		$shares = \OCP\Share::getItemShared('file', null);
+
+		if ($shares === false) {
+			return new \OC_OCS_Result(null, 404, 'could not get shares');
+		} else {
+			foreach ($shares as &$share) {
+				if ($share['item_type'] === 'file' && isset($share['path'])) {
+					$share['mimetype'] = \OC_Helper::getFileNameMimeType($share['path']);
+					if (\OC::$server->getPreviewManager()->isMimeSupported($share['mimetype'])) {
+						$share['isPreviewAvailable'] = true;
+					}
+				}
+			}
+			return new \OC_OCS_Result($shares);
+		}
+
+	}
+
+	/**
+	 * get share information for a given share
+	 *
+	 * @param array $params which contains a 'id'
+	 * @return \OC_OCS_Result share information
+	 */
+	public static function getShare($params) {
+
+		$s = self::getShareFromId($params['id']);
+		$params['itemSource'] = $s['file_source'];
+		$params['itemType'] = $s['item_type'];
+		$params['specificShare'] = true;
+
+		return self::collectShares($params);
+	}
+
+	/**
+	 * collect all share information, either of a specific share or all
+	 *        shares for a given path
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	private static function collectShares($params) {
+
+		$itemSource = $params['itemSource'];
+		$itemType = $params['itemType'];
+		$getSpecificShare = isset($params['specificShare']) ? $params['specificShare'] : false;
+
+		if ($itemSource !== null) {
+			$shares = \OCP\Share::getItemShared($itemType, $itemSource);
+			$receivedFrom = \OCP\Share::getItemSharedWithBySource($itemType, $itemSource);
+			// if a specific share was specified only return this one
+			if ($getSpecificShare === true) {
+				foreach ($shares as $share) {
+					if ($share['id'] === (int) $params['id']) {
+						$shares = array('element' => $share);
+						break;
+					}
+				}
+			} else {
+				$path = $params['path'];
+				foreach ($shares as $key => $share) {
+					$shares[$key]['path'] = $path;
+				}
+			}
+
+
+			// include also reshares in the lists. This means that the result
+			// will contain every user with access to the file.
+			if (isset($params['reshares']) && $params['reshares'] === true) {
+				$shares = self::addReshares($shares, $itemSource);
+			}
+
+			if ($receivedFrom) {
+				foreach ($shares as $key => $share) {
+					$shares[$key]['received_from'] = $receivedFrom['uid_owner'];
+					$shares[$key]['received_from_displayname'] = \OCP\User::getDisplayName($receivedFrom['uid_owner']);
+				}
+			}
+		} else {
+			$shares = null;
+		}
+
+		if ($shares === null || empty($shares)) {
+			return new \OC_OCS_Result(null, 404, 'share doesn\'t exist');
+		} else {
+			return new \OC_OCS_Result($shares);
+		}
+	}
+
+	/**
+	 * add reshares to a array of shares
+	 * @param array $shares array of shares
+	 * @param int $itemSource item source ID
+	 * @return array new shares array which includes reshares
+	 */
+	private static function addReshares($shares, $itemSource) {
+
+		// if there are no shares than there are also no reshares
+		$firstShare = reset($shares);
+		if ($firstShare) {
+			$path = $firstShare['path'];
+		} else {
+			return $shares;
+		}
+
+		$select = '`*PREFIX*share`.`id`, `item_type`, `*PREFIX*share`.`parent`, `share_type`, `share_with`, `file_source`, `path` , `*PREFIX*share`.`permissions`, `stime`, `expiration`, `token`, `storage`, `mail_send`, `mail_send`';
+		$getReshares = \OC_DB::prepare('SELECT ' . $select . ' FROM `*PREFIX*share` INNER JOIN `*PREFIX*filecache` ON `file_source` = `*PREFIX*filecache`.`fileid` WHERE `*PREFIX*share`.`file_source` = ? AND `*PREFIX*share`.`item_type` IN (\'file\', \'folder\') AND `uid_owner` != ?');
+		$reshares = $getReshares->execute(array($itemSource, \OCP\User::getUser()))->fetchAll();
+
+		foreach ($reshares as $key => $reshare) {
+			if (isset($reshare['share_with']) && $reshare['share_with'] !== '') {
+				$reshares[$key]['share_with_displayname'] = \OCP\User::getDisplayName($reshare['share_with']);
+			}
+			// add correct path to the result
+			$reshares[$key]['path'] = $path;
+		}
+
+		return array_merge($shares, $reshares);
+	}
+
+	/**
+	 * get share from all files in a given folder (non-recursive)
+	 * @param array $params contains 'path' to the folder
+	 * @return \OC_OCS_Result
+	 */
+	private static function getSharesFromFolder($params) {
+		$path = $params['path'];
+		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
+
+		if(!$view->is_dir($path)) {
+			return new \OC_OCS_Result(null, 400, "not a directory");
+		}
+
+		$content = $view->getDirectoryContent($path);
+
+		$result = array();
+		foreach ($content as $file) {
+			// workaround because folders are named 'dir' in this context
+			$itemType = $file['type'] === 'file' ? 'file' : 'folder';
+			$share = \OCP\Share::getItemShared($itemType, $file['fileid']);
+			if($share) {
+				$receivedFrom =  \OCP\Share::getItemSharedWithBySource($itemType, $file['fileid']);
+				reset($share);
+				$key = key($share);
+				if ($receivedFrom) {
+					$share[$key]['received_from'] = $receivedFrom['uid_owner'];
+					$share[$key]['received_from_displayname'] = \OCP\User::getDisplayName($receivedFrom['uid_owner']);
+				}
+				$result = array_merge($result, $share);
+			}
+		}
+
+		return new \OC_OCS_Result($result);
+	}
+
+	/**
+	 * get files shared with the user
+	 * @return \OC_OCS_Result
+	 */
+	private static function getFilesSharedWithMe() {
+		try	{
+			$shares = \OCP\Share::getItemsSharedWith('file');
+			foreach ($shares as &$share) {
+				if ($share['item_type'] === 'file') {
+					$share['mimetype'] = \OC_Helper::getFileNameMimeType($share['file_target']);
+					if (\OC::$server->getPreviewManager()->isMimeSupported($share['mimetype'])) {
+						$share['isPreviewAvailable'] = true;
+					}
+				}
+			}
+			$result = new \OC_OCS_Result($shares);
+		} catch (\Exception $e) {
+			$result = new \OC_OCS_Result(null, 403, $e->getMessage());
+		}
+
+		return $result;
+
+	}
+
+	/**
+	 * create a new share
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	public static function createShare($params) {
+
+		$path = isset($_POST['path']) ? $_POST['path'] : null;
+
+		if($path === null) {
+			return new \OC_OCS_Result(null, 400, "please specify a file or folder path");
+		}
+		$itemSource = self::getFileId($path);
+		$itemType = self::getItemType($path);
+
+		if($itemSource === null) {
+			return new \OC_OCS_Result(null, 404, "wrong path, file/folder doesn't exist.");
+		}
+
+		$shareWith = isset($_POST['shareWith']) ? $_POST['shareWith'] : null;
+		$shareType = isset($_POST['shareType']) ? (int)$_POST['shareType'] : null;
+
+		switch($shareType) {
+			case \OCP\Share::SHARE_TYPE_USER:
+				$permissions = isset($_POST['permissions']) ? (int)$_POST['permissions'] : 31;
+				break;
+			case \OCP\Share::SHARE_TYPE_GROUP:
+				$permissions = isset($_POST['permissions']) ? (int)$_POST['permissions'] : 31;
+				break;
+			case \OCP\Share::SHARE_TYPE_LINK:
+				//allow password protection
+				$shareWith = isset($_POST['password']) ? $_POST['password'] : null;
+				//check public link share
+				$publicUploadEnabled = \OC::$server->getAppConfig()->getValue('core', 'shareapi_allow_public_upload', 'yes');
+				if(isset($_POST['publicUpload']) && $publicUploadEnabled !== 'yes') {
+					return new \OC_OCS_Result(null, 403, "public upload disabled by the administrator");
+				}
+				$publicUpload = isset($_POST['publicUpload']) ? $_POST['publicUpload'] : 'false';
+				// read, create, update (7) if public upload is enabled or
+				// read (1) if public upload is disabled
+				$permissions = $publicUpload === 'true' ? 7 : 1;
+				break;
+			default:
+				return new \OC_OCS_Result(null, 400, "unknown share type");
+		}
+
+		try	{
+			$token = \OCP\Share::shareItem(
+					$itemType,
+					$itemSource,
+					$shareType,
+					$shareWith,
+					$permissions
+					);
+		} catch (\Exception $e) {
+			return new \OC_OCS_Result(null, 403, $e->getMessage());
+		}
+
+		if ($token) {
+			$data = array();
+			$data['id'] = 'unknown';
+			$shares = \OCP\Share::getItemShared($itemType, $itemSource);
+			if(is_string($token)) { //public link share
+				foreach ($shares as $share) {
+					if ($share['token'] === $token) {
+						$data['id'] = $share['id'];
+						break;
+					}
+				}
+				$url = \OCP\Util::linkToPublic('files&t='.$token);
+				$data['url'] = $url; // '&' gets encoded to $amp;
+				$data['token'] = $token;
+
+			} else {
+				foreach ($shares as $share) {
+					if ($share['share_with'] === $shareWith && $share['share_type'] === $shareType) {
+						$data['id'] = $share['id'];
+						break;
+					}
+				}
+			}
+			return new \OC_OCS_Result($data);
+		} else {
+			return new \OC_OCS_Result(null, 404, "couldn't share file");
+		}
+	}
+
+	/**
+	 * update shares, e.g. password, permissions, etc
+	 * @param array $params shareId 'id' and the parameter we want to update
+	 *                      currently supported: permissions, password, publicUpload
+	 * @return \OC_OCS_Result
+	 */
+	public static function updateShare($params) {
+
+		$share = self::getShareFromId($params['id']);
+
+		if(!isset($share['file_source'])) {
+			return new \OC_OCS_Result(null, 404, "wrong share Id, share doesn't exist.");
+		}
+
+		try {
+			if(isset($params['_put']['permissions'])) {
+				return self::updatePermissions($share, $params);
+			} elseif (isset($params['_put']['password'])) {
+				return self::updatePassword($share, $params);
+			} elseif (isset($params['_put']['publicUpload'])) {
+				return self::updatePublicUpload($share, $params);
+			} elseif (isset($params['_put']['expireDate'])) {
+				return self::updateExpireDate($share, $params);
+			}
+		} catch (\Exception $e) {
+
+			return new \OC_OCS_Result(null, 400, $e->getMessage());
+		}
+
+		return new \OC_OCS_Result(null, 400, "Wrong or no update parameter given");
+
+	}
+
+	/**
+	 * update permissions for a share
+	 * @param array $share information about the share
+	 * @param array $params contains 'permissions'
+	 * @return \OC_OCS_Result
+	 */
+	private static function updatePermissions($share, $params) {
+
+		$itemSource = $share['item_source'];
+		$itemType = $share['item_type'];
+		$shareWith = $share['share_with'];
+		$shareType = $share['share_type'];
+		$permissions = isset($params['_put']['permissions']) ? (int)$params['_put']['permissions'] : null;
+
+		$publicUploadStatus = \OC::$server->getAppConfig()->getValue('core', 'shareapi_allow_public_upload', 'yes');
+		$publicUploadEnabled = ($publicUploadStatus === 'yes') ? true : false;
+
+
+		// only change permissions for public shares if public upload is enabled
+		// and we want to set permissions to 1 (read only) or 7 (allow upload)
+		if ( (int)$shareType === \OCP\Share::SHARE_TYPE_LINK ) {
+			if ($publicUploadEnabled === false || ($permissions !== 7 && $permissions !== 1)) {
+				return new \OC_OCS_Result(null, 400, "can't change permission for public link share");
+			}
+		}
+
+		try {
+			$return = \OCP\Share::setPermissions(
+					$itemType,
+					$itemSource,
+					$shareType,
+					$shareWith,
+					$permissions
+					);
+		} catch (\Exception $e) {
+			return new \OC_OCS_Result(null, 404, $e->getMessage());
+		}
+
+		if ($return) {
+			return new \OC_OCS_Result();
+		} else {
+			return new \OC_OCS_Result(null, 404, "couldn't set permissions");
+		}
+	}
+
+	/**
+	 * enable/disable public upload
+	 * @param array $share information about the share
+	 * @param array $params contains 'publicUpload' which can be 'yes' or 'no'
+	 * @return \OC_OCS_Result
+	 */
+	private static function updatePublicUpload($share, $params) {
+
+		$publicUploadEnabled = \OC::$server->getAppConfig()->getValue('core', 'shareapi_allow_public_upload', 'yes');
+		if($publicUploadEnabled !== 'yes') {
+			return new \OC_OCS_Result(null, 403, "public upload disabled by the administrator");
+		}
+
+		if ($share['item_type'] !== 'folder' ||
+				(int)$share['share_type'] !== \OCP\Share::SHARE_TYPE_LINK ) {
+			return new \OC_OCS_Result(null, 400, "public upload is only possible for public shared folders");
+		}
+
+		// read, create, update (7) if public upload is enabled or
+		// read (1) if public upload is disabled
+		$params['_put']['permissions'] = $params['_put']['publicUpload'] === 'true' ? 7 : 1;
+
+		return self::updatePermissions($share, $params);
+
+	}
+
+	/**
+	 * set expire date for public link share
+	 * @param array $share information about the share
+	 * @param array $params contains 'expireDate' which needs to be a well formated date string, e.g DD-MM-YYYY
+	 * @return \OC_OCS_Result
+	 */
+	private static function updateExpireDate($share, $params) {
+		// only public links can have a expire date
+		if ((int)$share['share_type'] !== \OCP\Share::SHARE_TYPE_LINK ) {
+			return new \OC_OCS_Result(null, 400, "expire date only exists for public link shares");
+		}
+
+		try {
+			$expireDateSet = \OCP\Share::setExpirationDate($share['item_type'], $share['item_source'], $params['_put']['expireDate'], (int)$share['stime']);
+			$result = ($expireDateSet) ? new \OC_OCS_Result() : new \OC_OCS_Result(null, 404, "couldn't set expire date");
+		} catch (\Exception $e) {
+			$result = new \OC_OCS_Result(null, 404, $e->getMessage());
+		}
+
+		return $result;
+
+	}
+
+	/**
+	 * update password for public link share
+	 * @param array $share information about the share
+	 * @param array $params 'password'
+	 * @return \OC_OCS_Result
+	 */
+	private static function updatePassword($share, $params) {
+
+		$itemSource = $share['item_source'];
+		$itemType = $share['item_type'];
+
+		if( (int)$share['share_type'] !== \OCP\Share::SHARE_TYPE_LINK) {
+			return  new \OC_OCS_Result(null, 400, "password protection is only supported for public shares");
+		}
+
+		$shareWith = isset($params['_put']['password']) ? $params['_put']['password'] : null;
+
+		if($shareWith === '') {
+			$shareWith = null;
+		}
+
+		$items = \OCP\Share::getItemShared($itemType, $itemSource);
+
+		$checkExists = false;
+		foreach ($items as $item) {
+			if($item['share_type'] === \OCP\Share::SHARE_TYPE_LINK) {
+				$checkExists = true;
+				$permissions = $item['permissions'];
+			}
+		}
+
+		if (!$checkExists) {
+			return  new \OC_OCS_Result(null, 404, "share doesn't exists, can't change password");
+		}
+
+		try {
+			$result = \OCP\Share::shareItem(
+					$itemType,
+					$itemSource,
+					\OCP\Share::SHARE_TYPE_LINK,
+					$shareWith,
+					$permissions
+					);
+		} catch (\Exception $e) {
+			return new \OC_OCS_Result(null, 403, $e->getMessage());
+		}
+
+		if($result) {
+			return new \OC_OCS_Result();
+		}
+
+		return new \OC_OCS_Result(null, 404, "couldn't set password");
+	}
+
+	/**
+	 * unshare a file/folder
+	 * @param array $params contains the shareID 'id' which should be unshared
+	 * @return \OC_OCS_Result
+	 */
+	public static function deleteShare($params) {
+
+		$share = self::getShareFromId($params['id']);
+		$fileSource = isset($share['file_source']) ? $share['file_source'] : null;
+		$itemType = isset($share['item_type']) ? $share['item_type'] : null;;
+
+		if($fileSource === null) {
+			return new \OC_OCS_Result(null, 404, "wrong share ID, share doesn't exist.");
+		}
+
+		$shareWith = isset($share['share_with']) ? $share['share_with'] : null;
+		$shareType = isset($share['share_type']) ? (int)$share['share_type'] : null;
+
+		if( $shareType === \OCP\Share::SHARE_TYPE_LINK) {
+			$shareWith = null;
+		}
+
+		try {
+			$return = \OCP\Share::unshare(
+					$itemType,
+					$fileSource,
+					$shareType,
+					$shareWith);
+		} catch (\Exception $e) {
+			return new \OC_OCS_Result(null, 404, $e->getMessage());
+		}
+
+		if ($return) {
+			return new \OC_OCS_Result();
+		} else {
+			$msg = "Unshare Failed";
+			return new \OC_OCS_Result(null, 404, $msg);
+		}
+	}
+
+	/**
+	 * get file ID from a given path
+	 * @param string $path
+	 * @return string fileID or null
+	 */
+	private static function getFileId($path) {
+
+		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
+		$fileId = null;
+		$fileInfo = $view->getFileInfo($path);
+		if ($fileInfo) {
+			$fileId = $fileInfo['fileid'];
+		}
+
+		return $fileId;
+	}
+
+	/**
+	 * get itemType
+	 * @param string $path
+	 * @return string type 'file', 'folder' or null of file/folder doesn't exists
+	 */
+	private static function getItemType($path) {
+		$view = new \OC\Files\View('/'.\OCP\User::getUser().'/files');
+		$itemType = null;
+
+		if ($view->is_dir($path)) {
+			$itemType = "folder";
+		} elseif ($view->is_file($path)) {
+			$itemType = "file";
+		}
+
+		return $itemType;
+	}
+
+	/**
+	 * get some information from a given share
+	 * @param int $shareID
+	 * @return array with: item_source, share_type, share_with, item_type, permissions
+	 */
+	private static function getShareFromId($shareID) {
+		$sql = 'SELECT `file_source`, `item_source`, `share_type`, `share_with`, `item_type`, `permissions`, `stime` FROM `*PREFIX*share` WHERE `id` = ?';
+		$args = array($shareID);
+		$query = \OCP\DB::prepare($sql);
+		$result = $query->execute($args);
+
+		if (\OCP\DB::isError($result)) {
+			\OCP\Util::writeLog('files_sharing', \OC_DB::getErrorMessage($result), \OCP\Util::ERROR);
+			return null;
+		}
+		if ($share = $result->fetchRow()) {
+			return $share;
+		}
+
+		return null;
+
+	}
+
+}
diff --git a/apps/files_sharing/api/server2server.php b/apps/files_sharing/api/server2server.php
new file mode 100644
index 00000000000..2949e2dd09c
--- /dev/null
+++ b/apps/files_sharing/api/server2server.php
@@ -0,0 +1,224 @@
+<?php
+/**
+ * ownCloud - OCS API for server-to-server shares
+ *
+ * @copyright (C) 2014 ownCloud, Inc.
+ *
+ * @author Bjoern Schiessle <schiessle@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/>.
+ *
+ */
+
+namespace OCA\Files_Sharing\API;
+
+class Server2Server {
+
+	/**
+	 * create a new share
+	 *
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	public function createShare($params) {
+
+		if (!$this->isS2SEnabled(true)) {
+			return \OC_OCS_Result(null, 503, 'Server does not support server-to-server sharing');
+		}
+
+		$remote = isset($_POST['remote']) ? $_POST['remote'] : null;
+		$token = isset($_POST['token']) ? $_POST['token'] : null;
+		$name = isset($_POST['name']) ? $_POST['name'] : null;
+		$owner = isset($_POST['owner']) ? $_POST['owner'] : null;
+		$shareWith = isset($_POST['shareWith']) ? $_POST['shareWith'] : null;
+		$remoteId = isset($_POST['remote_id']) ? (int)$_POST['remote_id'] : null;
+
+		if ($remote && $token && $name && $owner && $remoteId && $shareWith) {
+
+			if(!\OCP\Util::isValidFileName($name)) {
+				return new \OC_OCS_Result(null, 400, 'The mountpoint name contains invalid characters.');
+			}
+
+			if (!\OCP\User::userExists($shareWith)) {
+				return new \OC_OCS_Result(null, 400, 'User does not exists');
+			}
+
+			\OC_Util::setupFS($shareWith);
+
+			$mountPoint = \OC\Files\Filesystem::normalizePath('/' . $name);
+			$name = \OCP\Files::buildNotExistingFileName('/', $name);
+
+			try {
+				\OCA\Files_Sharing\Helper::addServer2ServerShare($remote, $token, $name, $mountPoint, $owner, $shareWith, '', $remoteId);
+
+				\OC::$server->getActivityManager()->publishActivity(
+						'files_sharing', \OCA\Files_Sharing\Activity::SUBJECT_REMOTE_SHARE_RECEIVED, array($owner), '', array(),
+						'', '', $shareWith, \OCA\Files_Sharing\Activity::TYPE_REMOTE_SHARE, \OCA\Files_Sharing\Activity::PRIORITY_LOW);
+
+				return new \OC_OCS_Result();
+			} catch (\Exception $e) {
+				return new \OC_OCS_Result(null, 500, 'server can not add remote share, ' . $e->getMessage());
+			}
+		}
+
+		return new \OC_OCS_Result(null, 400, 'server can not add remote share, missing parameter');
+	}
+
+	/**
+	 * accept server-to-server share
+	 *
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	public function acceptShare($params) {
+
+		if (!$this->isS2SEnabled()) {
+			return \OC_OCS_Result(null, 503, 'Server does not support server-to-server sharing');
+		}
+
+		$id = $params['id'];
+		$token = isset($_POST['token']) ? $_POST['token'] : null;
+		$share = self::getShare($id, $token);
+
+		if ($share) {
+			list($file, $link) = self::getFile($share['uid_owner'], $share['file_source']);
+
+			\OC::$server->getActivityManager()->publishActivity(
+					'files_sharing', \OCA\Files_Sharing\Activity::SUBJECT_REMOTE_SHARE_ACCEPTED, array($share['share_with'], basename($file)), '', array(),
+					$file, $link, $share['uid_owner'], \OCA\Files_Sharing\Activity::TYPE_REMOTE_SHARE, \OCA\Files_Sharing\Activity::PRIORITY_LOW);
+		}
+
+		return new \OC_OCS_Result();
+	}
+
+	/**
+	 * decline server-to-server share
+	 *
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	public function declineShare($params) {
+
+		if (!$this->isS2SEnabled()) {
+			return \OC_OCS_Result(null, 503, 'Server does not support server-to-server sharing');
+		}
+
+		$id = $params['id'];
+		$token = isset($_POST['token']) ? $_POST['token'] : null;
+
+		$share = $this->getShare($id, $token);
+
+		if ($share) {
+			// userId must be set to the user who unshares
+			\OCP\Share::unshare($share['item_type'], $share['item_source'], $share['share_type'], null, $share['uid_owner']);
+
+			list($file, $link) = $this->getFile($share['uid_owner'], $share['file_source']);
+
+			\OC::$server->getActivityManager()->publishActivity(
+					'files_sharing', \OCA\Files_Sharing\Activity::SUBJECT_REMOTE_SHARE_DECLINED, array($share['share_with'], basename($file)), '', array(),
+					$file, $link, $share['uid_owner'], \OCA\Files_Sharing\Activity::TYPE_REMOTE_SHARE, \OCA\Files_Sharing\Activity::PRIORITY_LOW);
+		}
+
+		return new \OC_OCS_Result();
+	}
+
+	/**
+	 * remove server-to-server share if it was unshared by the owner
+	 *
+	 * @param array $params
+	 * @return \OC_OCS_Result
+	 */
+	public function unshare($params) {
+
+		if (!$this->isS2SEnabled()) {
+			return \OC_OCS_Result(null, 503, 'Server does not support server-to-server sharing');
+		}
+
+		$id = $params['id'];
+		$token = isset($_POST['token']) ? $_POST['token'] : null;
+
+		$query = \OCP\DB::prepare('SELECT * FROM `*PREFIX*share_external` WHERE `remote_id` = ? AND `share_token` = ?');
+		$query->execute(array($id, $token));
+		$share = $query->fetchRow();
+
+		if ($token && $id && !empty($share)) {
+
+			$owner = $share['owner'] . '@' . $share['remote'];
+			$mountpoint = $share['mountpoint'];
+			$user = $share['user'];
+
+			$query = \OCP\DB::prepare('DELETE FROM `*PREFIX*share_external` WHERE `remote_id` = ? AND `share_token` = ?');
+			$query->execute(array($id, $token));
+
+			\OC::$server->getActivityManager()->publishActivity(
+					'files_sharing', \OCA\Files_Sharing\Activity::SUBJECT_REMOTE_SHARE_DECLINED, array($owner, $mountpoint), '', array(),
+					'', '', $user, \OCA\Files_Sharing\Activity::TYPE_REMOTE_SHARE, \OCA\Files_Sharing\Activity::PRIORITY_MEDIUM);
+		}
+
+		return new \OC_OCS_Result();
+	}
+
+	/**
+	 * get share
+	 *
+	 * @param int $id
+	 * @param string $token
+	 * @return array
+	 */
+	private function getShare($id, $token) {
+		$query = \OCP\DB::prepare('SELECT * FROM `*PREFIX*share` WHERE `id` = ? AND `token` = ? AND `share_type` = ?');
+		$query->execute(array($id, $token, \OCP\Share::SHARE_TYPE_REMOTE));
+		$share = $query->fetchRow();
+
+		return $share;
+	}
+
+	/**
+	 * get file
+	 *
+	 * @param string $user
+	 * @param int $fileSource
+	 * @return array with internal path of the file and a absolute link to it
+	 */
+	private function getFile($user, $fileSource) {
+		\OC_Util::setupFS($user);
+
+		$file = \OC\Files\Filesystem::getPath($fileSource);
+		$args = \OC\Files\Filesystem::is_dir($file) ? array('dir' => $file) : array('dir' => dirname($file), 'scrollto' => $file);
+		$link = \OCP\Util::linkToAbsolute('files', 'index.php', $args);
+
+		return array($file, $link);
+
+	}
+
+	/**
+	 * check if server-to-server sharing is enabled
+	 *
+	 * @param bool $incoming
+	 * @return bool
+	 */
+	private function isS2SEnabled($incoming = false) {
+
+		$result = \OCP\App::isEnabled('files_sharing');
+
+		if ($incoming) {
+			$result = $result && \OCA\Files_Sharing\Helper::isIncomingServer2serverShareEnabled();
+		} else {
+			$result = $result && \OCA\Files_Sharing\Helper::isOutgoingServer2serverShareEnabled();
+		}
+
+		return $result;
+	}
+
+}