diff --git a/apps/dav/lib/connector/sabre/file.php b/apps/dav/lib/connector/sabre/file.php
index b925a67040..be313a91e8 100644
--- a/apps/dav/lib/connector/sabre/file.php
+++ b/apps/dav/lib/connector/sabre/file.php
@@ -214,7 +214,13 @@ class File extends Node implements IFile {
 					header('X-OC-MTime: accepted');
 				}
 			}
+
+			if (isset($request->server['HTTP_OC_CHECKSUM'])) {
+				$checksum = trim($request->server['HTTP_OC_CHECKSUM']);
+				$this->fileView->putFileInfo($this->path, ['checksum' => $checksum]);
+			}
 			$this->refreshInfo();
+
 		} catch (StorageNotAvailableException $e) {
 			throw new ServiceUnavailable("Failed to check file size: " . $e->getMessage());
 		}
@@ -528,4 +534,13 @@ class File extends Node implements IFile {
 
 		throw new \Sabre\DAV\Exception($e->getMessage(), 0, $e);
 	}
+
+	/**
+	 * Get the checksum for this file
+	 *
+	 * @return string
+	 */
+	public function getChecksum() {
+		return $this->info->getChecksum();
+	}
 }
diff --git a/apps/dav/lib/connector/sabre/filesplugin.php b/apps/dav/lib/connector/sabre/filesplugin.php
index ef139eae94..82d0001490 100644
--- a/apps/dav/lib/connector/sabre/filesplugin.php
+++ b/apps/dav/lib/connector/sabre/filesplugin.php
@@ -47,6 +47,7 @@ class FilesPlugin extends \Sabre\DAV\ServerPlugin {
 	const LASTMODIFIED_PROPERTYNAME = '{DAV:}lastmodified';
 	const OWNER_ID_PROPERTYNAME = '{http://owncloud.org/ns}owner-id';
 	const OWNER_DISPLAY_NAME_PROPERTYNAME = '{http://owncloud.org/ns}owner-display-name';
+	const CHECKSUM_PROPERTYNAME = '{http://owncloud.org/ns}checksum';
 
 	/**
 	 * Reference to main server object
@@ -107,6 +108,7 @@ class FilesPlugin extends \Sabre\DAV\ServerPlugin {
 		$server->protectedProperties[] = self::DOWNLOADURL_PROPERTYNAME;
 		$server->protectedProperties[] = self::OWNER_ID_PROPERTYNAME;
 		$server->protectedProperties[] = self::OWNER_DISPLAY_NAME_PROPERTYNAME;
+		$server->protectedProperties[] = self::CHECKSUM_PROPERTYNAME;
 
 		// normally these cannot be changed (RFC4918), but we want them modifiable through PROPPATCH
 		$allowedProperties = ['{DAV:}getetag'];
@@ -178,8 +180,8 @@ class FilesPlugin extends \Sabre\DAV\ServerPlugin {
 	}
 
 	/**
-	 * Plugin that adds a 'Content-Disposition: attachment' header to all files
-	 * delivered by SabreDAV.
+	 * Add headers to file download
+	 *
 	 * @param RequestInterface $request
 	 * @param ResponseInterface $response
 	 */
@@ -188,7 +190,15 @@ class FilesPlugin extends \Sabre\DAV\ServerPlugin {
 		$node = $this->tree->getNodeForPath($request->getPath());
 		if (!($node instanceof IFile)) return;
 
+		// adds a 'Content-Disposition: attachment' header
 		$response->addHeader('Content-Disposition', 'attachment');
+
+		//Add OC-Checksum header
+		/** @var $node File */
+		$checksum = $node->getChecksum();
+		if ($checksum !== null) {
+			$response->addHeader('OC-Checksum', $checksum);
+		}
 	}
 
 	/**
@@ -237,6 +247,16 @@ class FilesPlugin extends \Sabre\DAV\ServerPlugin {
 				}
 				return false;
 			});
+
+			$propFind->handle(self::CHECKSUM_PROPERTYNAME, function() use ($node) {
+				$checksum = $node->getChecksum();
+
+				if ($checksum === null) {
+					return '';
+				}
+				return $checksum;
+			});
+
 		}
 
 		if ($node instanceof \OCA\DAV\Connector\Sabre\Directory) {
diff --git a/db_structure.xml b/db_structure.xml
index ea1b89e28d..dbbfa8c7a4 100644
--- a/db_structure.xml
+++ b/db_structure.xml
@@ -397,6 +397,14 @@
                 <length>4</length>
             </field>
 
+			<field>
+				<name>checksum</name>
+				<type>text</type>
+				<default></default>
+				<notnull>false</notnull>
+				<length>255</length>
+			</field>
+
 
             <index>
 				<name>fs_storage_path_hash</name>
diff --git a/lib/private/files/cache/cache.php b/lib/private/files/cache/cache.php
index 30e00b6080..cbe48f21bd 100644
--- a/lib/private/files/cache/cache.php
+++ b/lib/private/files/cache/cache.php
@@ -121,7 +121,7 @@ class Cache implements ICache {
 			$params = array($file);
 		}
 		$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`,
-					   `storage_mtime`, `encrypted`, `etag`, `permissions`
+					   `storage_mtime`, `encrypted`, `etag`, `permissions`, `checksum`
 				FROM `*PREFIX*filecache` ' . $where;
 		$result = $this->connection->executeQuery($sql, $params);
 		$data = $result->fetch();
@@ -177,7 +177,7 @@ class Cache implements ICache {
 	public function getFolderContentsById($fileId) {
 		if ($fileId > -1) {
 			$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`,
-						   `storage_mtime`, `encrypted`, `etag`, `permissions`
+						   `storage_mtime`, `encrypted`, `etag`, `permissions`, `checksum`
 					FROM `*PREFIX*filecache` WHERE `parent` = ? ORDER BY `name` ASC';
 			$result = $this->connection->executeQuery($sql, [$fileId]);
 			$files = $result->fetchAll();
@@ -287,7 +287,10 @@ class Cache implements ICache {
 		// don't update if the data we try to set is the same as the one in the record
 		// some databases (Postgres) don't like superfluous updates
 		$sql = 'UPDATE `*PREFIX*filecache` SET ' . implode(' = ?, ', $queryParts) . '=? ' .
-			'WHERE (' . implode(' <> ? OR ', $queryParts) . ' <> ? ) AND `fileid` = ? ';
+			'WHERE (' .
+			implode(' <> ? OR ', $queryParts) . ' <> ? OR ' .
+			implode(' IS NULL OR ', $queryParts) . ' IS NULL' .
+			') AND `fileid` = ? ';
 		$this->connection->executeQuery($sql, $params);
 
 	}
@@ -303,7 +306,7 @@ class Cache implements ICache {
 	protected function buildParts(array $data) {
 		$fields = array(
 			'path', 'parent', 'name', 'mimetype', 'size', 'mtime', 'storage_mtime', 'encrypted',
-			'etag', 'permissions');
+			'etag', 'permissions', 'checksum');
 
 		$doNotCopyStorageMTime = false;
 		if (array_key_exists('mtime', $data) && $data['mtime'] === null) {
@@ -567,7 +570,7 @@ class Cache implements ICache {
 		$sql = '
 			SELECT `fileid`, `storage`, `path`, `parent`, `name`,
 				`mimetype`, `mimepart`, `size`, `mtime`, `encrypted`,
-				`etag`, `permissions`
+				`etag`, `permissions`, `checksum`
 			FROM `*PREFIX*filecache`
 			WHERE `storage` = ? AND `name` ILIKE ?';
 		$result = $this->connection->executeQuery($sql,
@@ -598,7 +601,7 @@ class Cache implements ICache {
 		} else {
 			$where = '`mimepart` = ?';
 		}
-		$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`, `encrypted`, `etag`, `permissions`
+		$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`, `encrypted`, `etag`, `permissions`, `checksum`
 				FROM `*PREFIX*filecache` WHERE ' . $where . ' AND `storage` = ?';
 		$mimetype = $this->mimetypeLoader->getId($mimetype);
 		$result = $this->connection->executeQuery($sql, array($mimetype, $this->getNumericStorageId()));
@@ -625,7 +628,7 @@ class Cache implements ICache {
 	public function searchByTag($tag, $userId) {
 		$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, ' .
 			'`mimetype`, `mimepart`, `size`, `mtime`, ' .
-			'`encrypted`, `etag`, `permissions` ' .
+			'`encrypted`, `etag`, `permissions`, `checksum` ' .
 			'FROM `*PREFIX*filecache` `file`, ' .
 			'`*PREFIX*vcategory_to_object` `tagmap`, ' .
 			'`*PREFIX*vcategory` `tag` ' .
diff --git a/lib/private/files/fileinfo.php b/lib/private/files/fileinfo.php
index 1e6fe474f7..f22e1099e2 100644
--- a/lib/private/files/fileinfo.php
+++ b/lib/private/files/fileinfo.php
@@ -327,4 +327,11 @@ class FileInfo implements \OCP\Files\FileInfo, \ArrayAccess {
 			$this->childEtags[] = $relativeEntryPath . '/' . $data['etag'] . $permissions;
 		}
 	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public function getChecksum() {
+		return $this->data['checksum'];
+	}
 }
diff --git a/lib/private/files/node/file.php b/lib/private/files/node/file.php
index c3d18cdb35..cf163b9b76 100644
--- a/lib/private/files/node/file.php
+++ b/lib/private/files/node/file.php
@@ -164,4 +164,11 @@ class File extends Node implements \OCP\Files\File {
 	public function hash($type, $raw = false) {
 		return $this->view->hash($type, $this->path, $raw);
 	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public function getChecksum() {
+		return $this->fileInfo->getChecksum();
+	}
 }
diff --git a/lib/private/files/node/node.php b/lib/private/files/node/node.php
index 7769f15ee5..9feccac50b 100644
--- a/lib/private/files/node/node.php
+++ b/lib/private/files/node/node.php
@@ -351,4 +351,8 @@ class Node implements \OCP\Files\Node {
 	public function getOwner() {
 		return $this->getFileInfo()->getOwner();
 	}
+
+	public function getChecksum() {
+		return;
+	}
 }
diff --git a/lib/public/files/fileinfo.php b/lib/public/files/fileinfo.php
index 77e37d53ab..aa4aa605d3 100644
--- a/lib/public/files/fileinfo.php
+++ b/lib/public/files/fileinfo.php
@@ -237,4 +237,12 @@ interface FileInfo {
 	 * @since 9.0.0
 	 */
 	public function getOwner();
+
+	/**
+	 * Get the stored checksum for this file
+	 *
+	 * @return string
+	 * @since 9.0.0
+	 */
+	public function getChecksum();
 }
diff --git a/version.php b/version.php
index 0b7eb6f79d..f807b01d7d 100644
--- a/version.php
+++ b/version.php
@@ -25,7 +25,7 @@
 // We only can count up. The 4. digit is only for the internal patchlevel to trigger DB upgrades
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
-$OC_Version = array(9, 0, 0, 8);
+$OC_Version = array(9, 0, 0, 9);
 
 // The human readable string
 $OC_VersionString = '9.0 pre alpha';