New SSE key format

* Encrypt the keys with the instance secret
* Store them as json (so we can add other things if needed)

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

10 files changed, 584 insertions, 30 deletions

diff --git a/core/Command/Encryption/MigrateKeyStorage.php b/core/Command/Encryption/MigrateKeyStorage.php
new file mode 100644
index 00000000000..099eba1e822
--- /dev/null
+++ b/core/Command/Encryption/MigrateKeyStorage.php
@@ -0,0 +1,261 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @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\Core\Command\Encryption;
+
+use OC\Encryption\Keys\Storage;
+use OC\Encryption\Util;
+use OC\Files\View;
+use OCP\IConfig;
+use OCP\IUserManager;
+use OCP\Security\ICrypto;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Helper\ProgressBar;
+use Symfony\Component\Console\Helper\QuestionHelper;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class MigrateKeyStorage extends Command {
+
+	/** @var View */
+	protected $rootView;
+
+	/** @var IUserManager */
+	protected $userManager;
+
+	/** @var IConfig */
+	protected $config;
+
+	/** @var Util */
+	protected $util;
+
+	/** @var QuestionHelper */
+	protected $questionHelper;
+	/**
+	 * @var ICrypto
+	 */
+	private $crypto;
+
+	public function __construct(View $view, IUserManager $userManager, IConfig $config, Util $util, ICrypto $crypto) {
+		parent::__construct();
+		$this->rootView = $view;
+		$this->userManager = $userManager;
+		$this->config = $config;
+		$this->util = $util;
+		$this->crypto = $crypto;
+	}
+
+	protected function configure() {
+		parent::configure();
+		$this
+			->setName('encryption:migrate-key-storage-format')
+			->setDescription('Migrate the format of the keystorage to a newer format');
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output): int {
+		$root = $this->util->getKeyStorageRoot();
+
+		$output->writeln("Updating key storage format");
+		$this->updateKeys($root, $output);
+		$output->writeln("Key storage format successfully updated");
+
+		return 0;
+	}
+
+	/**
+	 * move keys to new key storage root
+	 *
+	 * @param string $root
+	 * @param OutputInterface $output
+	 * @return bool
+	 * @throws \Exception
+	 */
+	protected function updateKeys(string $root, OutputInterface $output) {
+		$output->writeln("Start to update the keys:");
+
+		$this->updateSystemKeys($root);
+		$this->updateUsersKeys($root, $output);
+		$this->config->deleteSystemValue('encryption.key_storage_migrated');
+		return true;
+	}
+
+	/**
+	 * move system key folder
+	 *
+	 * @param string $root
+	 */
+	protected function updateSystemKeys($root) {
+		if (!$this->rootView->is_dir($root . '/files_encryption')) {
+			return;
+		}
+
+		$this->traverseKeys($root . '/files_encryption', null);
+	}
+
+	private function traverseKeys(string $folder, ?string $uid) {
+		$listing = $this->rootView->getDirectoryContent($folder);
+
+		foreach ($listing as $node) {
+			if ($node['mimetype'] === 'httpd/unix-directory') {
+				//ignore
+			} else {
+				$endsWith = function ($haystack, $needle) {
+					$length = strlen($needle);
+					if ($length === 0) {
+						return true;
+					}
+
+					return (substr($haystack, -$length) === $needle);
+				};
+
+				if ($node['name'] === 'fileKey' ||
+					$endsWith($node['name'], '.privateKey') ||
+					$endsWith($node['name'], '.publicKey') ||
+					$endsWith($node['name'], '.shareKey')) {
+					$path = $folder . '/' . $node['name'];
+
+					$content = $this->rootView->file_get_contents($path);
+
+					try {
+						$this->crypto->decrypt($content);
+						continue;
+					} catch (\Exception $e) {
+						// Ignore we now update the data.
+					}
+
+					$data = [
+						'key' => base64_encode($content),
+						'uid' => $uid,
+					];
+
+					$enc = $this->crypto->encrypt(json_encode($data));
+					$this->rootView->file_put_contents($path, $enc);
+				}
+			}
+		}
+	}
+
+	private function traverseFileKeys(string $folder) {
+		$listing = $this->rootView->getDirectoryContent($folder);
+
+		foreach ($listing as $node) {
+			if ($node['mimetype'] === 'httpd/unix-directory') {
+				$this->traverseFileKeys($folder . '/' . $node['name']);
+			} else {
+				$endsWith = function ($haystack, $needle) {
+					$length = strlen($needle);
+					if ($length === 0) {
+						return true;
+					}
+
+					return (substr($haystack, -$length) === $needle);
+				};
+
+				if ($node['name'] === 'fileKey' ||
+					$endsWith($node['name'], '.privateKey') ||
+					$endsWith($node['name'], '.publicKey') ||
+					$endsWith($node['name'], '.shareKey')) {
+					$path = $folder . '/' . $node['name'];
+
+					$content = $this->rootView->file_get_contents($path);
+
+					try {
+						$this->crypto->decrypt($content);
+						continue;
+					} catch (\Exception $e) {
+						// Ignore we now update the data.
+					}
+
+					$data = [
+						'key' => base64_encode($content)
+					];
+
+					$enc = $this->crypto->encrypt(json_encode($data));
+					$this->rootView->file_put_contents($path, $enc);
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * setup file system for the given user
+	 *
+	 * @param string $uid
+	 */
+	protected function setupUserFS($uid) {
+		\OC_Util::tearDownFS();
+		\OC_Util::setupFS($uid);
+	}
+
+
+	/**
+	 * iterate over each user and move the keys to the new storage
+	 *
+	 * @param string $root
+	 * @param OutputInterface $output
+	 */
+	protected function updateUsersKeys(string $root, OutputInterface $output) {
+		$progress = new ProgressBar($output);
+		$progress->start();
+
+		foreach ($this->userManager->getBackends() as $backend) {
+			$limit = 500;
+			$offset = 0;
+			do {
+				$users = $backend->getUsers('', $limit, $offset);
+				foreach ($users as $user) {
+					$progress->advance();
+					$this->setupUserFS($user);
+					$this->updateUserKeys($root, $user);
+				}
+				$offset += $limit;
+			} while (count($users) >= $limit);
+		}
+		$progress->finish();
+	}
+
+	/**
+	 * move user encryption folder to new root folder
+	 *
+	 * @param string $root
+	 * @param string $user
+	 * @throws \Exception
+	 */
+	protected function updateUserKeys(string $root, string $user) {
+		if ($this->userManager->userExists($user)) {
+			$source = $root . '/' . $user . '/files_encryption/OC_DEFAULT_MODULE';
+			if ($this->rootView->is_dir($source)) {
+				$this->traverseKeys($source, $user);
+			}
+
+			$source = $root . '/' . $user . '/files_encryption/keys';
+			if ($this->rootView->is_dir($source)) {
+				$this->traverseFileKeys($source);
+			}
+		}
+	}
+}
diff --git a/core/register_command.php b/core/register_command.php
index c2a3f76b6c3..e05cff3e37f 100644
--- a/core/register_command.php
+++ b/core/register_command.php
@@ -139,6 +139,14 @@ if (\OC::$server->getConfig()->getSystemValue('installed', false)) {
 		)
 	);
 	$application->add(new OC\Core\Command\Encryption\ShowKeyStorageRoot($util));
+	$application->add(new OC\Core\Command\Encryption\MigrateKeyStorage(
+			$view,
+			\OC::$server->getUserManager(),
+			\OC::$server->getConfig(),
+			$util,
+			\OC::$server->getCrypto()
+		)
+	);
 
 	$application->add(new OC\Core\Command\Maintenance\DataFingerprint(\OC::$server->getConfig(), new \OC\AppFramework\Utility\TimeFactory()));
 	$application->add(new OC\Core\Command\Maintenance\Mimetype\UpdateDB(\OC::$server->getMimeTypeDetector(), \OC::$server->getMimeTypeLoader()));
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index d3fb9181c3b..c0e35fa4604 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -808,6 +808,7 @@ return array(
     'OC\\Core\\Command\\Encryption\\Enable' => $baseDir . '/core/Command/Encryption/Enable.php',
     'OC\\Core\\Command\\Encryption\\EncryptAll' => $baseDir . '/core/Command/Encryption/EncryptAll.php',
     'OC\\Core\\Command\\Encryption\\ListModules' => $baseDir . '/core/Command/Encryption/ListModules.php',
+    'OC\\Core\\Command\\Encryption\\MigrateKeyStorage' => $baseDir . '/core/Command/Encryption/MigrateKeyStorage.php',
     'OC\\Core\\Command\\Encryption\\SetDefaultModule' => $baseDir . '/core/Command/Encryption/SetDefaultModule.php',
     'OC\\Core\\Command\\Encryption\\ShowKeyStorageRoot' => $baseDir . '/core/Command/Encryption/ShowKeyStorageRoot.php',
     'OC\\Core\\Command\\Encryption\\Status' => $baseDir . '/core/Command/Encryption/Status.php',
@@ -1248,6 +1249,7 @@ return array(
     'OC\\Repair\\NC16\\ClearCollectionsAccessCache' => $baseDir . '/lib/private/Repair/NC16/ClearCollectionsAccessCache.php',
     'OC\\Repair\\NC18\\ResetGeneratedAvatarFlag' => $baseDir . '/lib/private/Repair/NC18/ResetGeneratedAvatarFlag.php',
     'OC\\Repair\\NC20\\EncryptionLegacyCipher' => $baseDir . '/lib/private/Repair/NC20/EncryptionLegacyCipher.php',
+    'OC\\Repair\\NC20\\EncryptionMigration' => $baseDir . '/lib/private/Repair/NC20/EncryptionMigration.php',
     'OC\\Repair\\OldGroupMembershipShares' => $baseDir . '/lib/private/Repair/OldGroupMembershipShares.php',
     'OC\\Repair\\Owncloud\\DropAccountTermsTable' => $baseDir . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
     'OC\\Repair\\Owncloud\\SaveAccountsTableData' => $baseDir . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index e0ac8a31147..a1786bc1de0 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -837,6 +837,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Core\\Command\\Encryption\\Enable' => __DIR__ . '/../../..' . '/core/Command/Encryption/Enable.php',
         'OC\\Core\\Command\\Encryption\\EncryptAll' => __DIR__ . '/../../..' . '/core/Command/Encryption/EncryptAll.php',
         'OC\\Core\\Command\\Encryption\\ListModules' => __DIR__ . '/../../..' . '/core/Command/Encryption/ListModules.php',
+        'OC\\Core\\Command\\Encryption\\MigrateKeyStorage' => __DIR__ . '/../../..' . '/core/Command/Encryption/MigrateKeyStorage.php',
         'OC\\Core\\Command\\Encryption\\SetDefaultModule' => __DIR__ . '/../../..' . '/core/Command/Encryption/SetDefaultModule.php',
         'OC\\Core\\Command\\Encryption\\ShowKeyStorageRoot' => __DIR__ . '/../../..' . '/core/Command/Encryption/ShowKeyStorageRoot.php',
         'OC\\Core\\Command\\Encryption\\Status' => __DIR__ . '/../../..' . '/core/Command/Encryption/Status.php',
@@ -1277,6 +1278,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Repair\\NC16\\ClearCollectionsAccessCache' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/ClearCollectionsAccessCache.php',
         'OC\\Repair\\NC18\\ResetGeneratedAvatarFlag' => __DIR__ . '/../../..' . '/lib/private/Repair/NC18/ResetGeneratedAvatarFlag.php',
         'OC\\Repair\\NC20\\EncryptionLegacyCipher' => __DIR__ . '/../../..' . '/lib/private/Repair/NC20/EncryptionLegacyCipher.php',
+        'OC\\Repair\\NC20\\EncryptionMigration' => __DIR__ . '/../../..' . '/lib/private/Repair/NC20/EncryptionMigration.php',
         'OC\\Repair\\OldGroupMembershipShares' => __DIR__ . '/../../..' . '/lib/private/Repair/OldGroupMembershipShares.php',
         'OC\\Repair\\Owncloud\\DropAccountTermsTable' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
         'OC\\Repair\\Owncloud\\SaveAccountsTableData' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',
diff --git a/lib/private/Encryption/Keys/Storage.php b/lib/private/Encryption/Keys/Storage.php
index cee32691261..43a291b886c 100644
--- a/lib/private/Encryption/Keys/Storage.php
+++ b/lib/private/Encryption/Keys/Storage.php
@@ -31,8 +31,11 @@ namespace OC\Encryption\Keys;
 use OC\Encryption\Util;
 use OC\Files\Filesystem;
 use OC\Files\View;
+use OC\ServerNotAvailableException;
 use OC\User\NoUserException;
 use OCP\Encryption\Keys\IStorage;
+use OCP\IConfig;
+use OCP\Security\ICrypto;
 
 class Storage implements IStorage {
 
@@ -62,11 +65,17 @@ class Storage implements IStorage {
 	/** @var array */
 	private $keyCache = [];
 
+	/** @var ICrypto */
+	private $crypto;
+
+	/** @var IConfig */
+	private $config;
+
 	/**
 	 * @param View $view
 	 * @param Util $util
 	 */
-	public function __construct(View $view, Util $util) {
+	public function __construct(View $view, Util $util, ICrypto $crypto, IConfig $config) {
 		$this->view = $view;
 		$this->util = $util;
 
@@ -74,6 +83,8 @@ class Storage implements IStorage {
 		$this->keys_base_dir = $this->encryption_base_dir .'/keys';
 		$this->backup_base_dir = $this->encryption_base_dir .'/backup';
 		$this->root_dir = $this->util->getKeyStorageRoot();
+		$this->crypto = $crypto;
+		$this->config = $config;
 	}
 
 	/**
@@ -81,7 +92,7 @@ class Storage implements IStorage {
 	 */
 	public function getUserKey($uid, $keyId, $encryptionModuleId) {
 		$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, $uid);
-		return $this->getKey($path);
+		return base64_decode($this->getKeyWithUid($path, $uid));
 	}
 
 	/**
@@ -90,17 +101,17 @@ class Storage implements IStorage {
 	public function getFileKey($path, $keyId, $encryptionModuleId) {
 		$realFile = $this->util->stripPartialFileExtension($path);
 		$keyDir = $this->getFileKeyDir($encryptionModuleId, $realFile);
-		$key = $this->getKey($keyDir . $keyId);
+		$key = $this->getKey($keyDir . $keyId)['key'];
 
 		if ($key === '' && $realFile !== $path) {
 			// Check if the part file has keys and use them, if no normal keys
 			// exist. This is required to fix copyBetweenStorage() when we
 			// rename a .part file over storage borders.
 			$keyDir = $this->getFileKeyDir($encryptionModuleId, $path);
-			$key = $this->getKey($keyDir . $keyId);
+			$key = $this->getKey($keyDir . $keyId)['key'];
 		}
 
-		return $key;
+		return base64_decode($key);
 	}
 
 	/**
@@ -108,7 +119,7 @@ class Storage implements IStorage {
 	 */
 	public function getSystemUserKey($keyId, $encryptionModuleId) {
 		$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, null);
-		return $this->getKey($path);
+		return base64_decode($this->getKeyWithUid($path, null));
 	}
 
 	/**
@@ -116,7 +127,10 @@ class Storage implements IStorage {
 	 */
 	public function setUserKey($uid, $keyId, $key, $encryptionModuleId) {
 		$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, $uid);
-		return $this->setKey($path, $key);
+		return $this->setKey($path, [
+			'key' => base64_encode($key),
+			'uid' => $uid,
+		]);
 	}
 
 	/**
@@ -124,7 +138,9 @@ class Storage implements IStorage {
 	 */
 	public function setFileKey($path, $keyId, $key, $encryptionModuleId) {
 		$keyDir = $this->getFileKeyDir($encryptionModuleId, $path);
-		return $this->setKey($keyDir . $keyId, $key);
+		return $this->setKey($keyDir . $keyId, [
+			'key' => base64_encode($key),
+		]);
 	}
 
 	/**
@@ -132,7 +148,10 @@ class Storage implements IStorage {
 	 */
 	public function setSystemUserKey($keyId, $key, $encryptionModuleId) {
 		$path = $this->constructUserKeyPath($encryptionModuleId, $keyId, null);
-		return $this->setKey($path, $key);
+		return $this->setKey($path, [
+			'key' => base64_encode($key),
+			'uid' => null,
+		]);
 	}
 
 	/**
@@ -200,19 +219,106 @@ class Storage implements IStorage {
 	}
 
 	/**
+	 * @param string $path
+	 * @param string|null $uid
+	 * @return string
+	 * @throws ServerNotAvailableException
+	 *
+	 * Small helper function to fetch the key and verify the value for user and system keys
+	 */
+	private function getKeyWithUid(string $path, ?string $uid): string {
+		$data = $this->getKey($path);
+
+		if (!isset($data['key'])) {
+			throw new ServerNotAvailableException('Key is invalid');
+		}
+
+		if ($data['key'] === '') {
+			return '';
+		}
+
+		if (!array_key_exists('uid', $data) || $data['uid'] !== $uid) {
+			// If the migration is done we error out
+			$versionFromBeforeUpdate = $this->config->getSystemValue('version', '0.0.0.0');
+			if (version_compare($versionFromBeforeUpdate, '20.0.0.1', '<=')) {
+				return $data['key'];
+			}
+
+			if ($this->config->getSystemValueBool('encryption.key_storage_migrated', true)) {
+				throw new ServerNotAvailableException('Key has been modified');
+			} else {
+				//Otherwise we migrate
+				$data['uid'] = $uid;
+				$this->setKey($path, $data);
+			}
+		}
+
+		return $data['key'];
+	}
+
+	/**
 	 * read key from hard disk
 	 *
 	 * @param string $path to key
-	 * @return string
+	 * @return array containing key as base64encoded key, and possible the uid
 	 */
-	private function getKey($path) {
-		$key = '';
+	private function getKey($path): array {
+		$key = [
+			'key' => '',
+		];
 
 		if ($this->view->file_exists($path)) {
 			if (isset($this->keyCache[$path])) {
 				$key =  $this->keyCache[$path];
 			} else {
-				$key = $this->view->file_get_contents($path);
+				$data = $this->view->file_get_contents($path);
+
+				// Version <20.0.0.1 doesn't have this
+				$versionFromBeforeUpdate = $this->config->getSystemValue('version', '0.0.0.0');
+				if (version_compare($versionFromBeforeUpdate, '20.0.0.1', '<=')) {
+					$key = [
+						'key' => base64_encode($data),
+					];
+				} else {
+					if ($this->config->getSystemValueBool('encryption.key_storage_migrated', true)) {
+						try {
+							$clearData = $this->crypto->decrypt($data);
+						} catch (\Exception $e) {
+							throw new ServerNotAvailableException('Could not decrypt key', 0, $e);
+						}
+
+						$dataArray = json_decode($clearData, true);
+						if ($dataArray === null) {
+							throw new ServerNotAvailableException('Invalid encryption key');
+						}
+
+						$key = $dataArray;
+					} else {
+						/*
+						 * Even if not all keys are migrated we should still try to decrypt it (in case some have moved).
+						 * However it is only a failure now if it is an array and decryption fails
+						 */
+						$fallback = false;
+						try {
+							$clearData = $this->crypto->decrypt($data);
+						} catch (\Exception $e) {
+							$fallback = true;
+						}
+
+						if (!$fallback) {
+							$dataArray = json_decode($clearData, true);
+							if ($dataArray === null) {
+								throw new ServerNotAvailableException('Invalid encryption key');
+							}
+							$key = $dataArray;
+						} else {
+							$key = [
+								'key' => base64_encode($data),
+							];
+						}
+					}
+				}
+
 				$this->keyCache[$path] = $key;
 			}
 		}
@@ -225,13 +331,23 @@ class Storage implements IStorage {
 	 *
 	 *
 	 * @param string $path path to key directory
-	 * @param string $key key
+	 * @param array $key key
 	 * @return bool
 	 */
 	private function setKey($path, $key) {
 		$this->keySetPreparation(dirname($path));
 
-		$result = $this->view->file_put_contents($path, $key);
+		$versionFromBeforeUpdate = $this->config->getSystemValue('version', '0.0.0.0');
+		if (version_compare($versionFromBeforeUpdate, '20.0.0.1', '<=')) {
+			// Only store old format if this happens during the migration.
+			// TODO: Remove for 21
+			$data = base64_decode($key['key']);
+		} else {
+			// Wrap the data
+			$data = $this->crypto->encrypt(json_encode($key));
+		}
+
+		$result = $this->view->file_put_contents($path, $data);
 
 		if (is_int($result) && $result > 0) {
 			$this->keyCache[$path] = $key;
diff --git a/lib/private/Repair.php b/lib/private/Repair.php
index 6151812d316..4ad21e74238 100644
--- a/lib/private/Repair.php
+++ b/lib/private/Repair.php
@@ -49,6 +49,7 @@ use OC\Repair\NC16\CleanupCardDAVPhotoCache;
 use OC\Repair\NC16\ClearCollectionsAccessCache;
 use OC\Repair\NC18\ResetGeneratedAvatarFlag;
 use OC\Repair\NC20\EncryptionLegacyCipher;
+use OC\Repair\NC20\EncryptionMigration;
 use OC\Repair\OldGroupMembershipShares;
 use OC\Repair\Owncloud\DropAccountTermsTable;
 use OC\Repair\Owncloud\SaveAccountsTableData;
@@ -158,6 +159,7 @@ class Repair implements IOutput {
 			new ClearCollectionsAccessCache(\OC::$server->getConfig(), \OC::$server->query(IManager::class)),
 			\OC::$server->query(ResetGeneratedAvatarFlag::class),
 			\OC::$server->query(EncryptionLegacyCipher::class),
+			\OC::$server->query(EncryptionMigration::class),
 		];
 	}
 
diff --git a/lib/private/Repair/NC20/EncryptionMigration.php b/lib/private/Repair/NC20/EncryptionMigration.php
new file mode 100644
index 00000000000..6d5c2dc0c58
--- /dev/null
+++ b/lib/private/Repair/NC20/EncryptionMigration.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @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\Repair\NC20;
+
+use OCP\Encryption\IManager;
+use OCP\IConfig;
+use OCP\Migration\IOutput;
+use OCP\Migration\IRepairStep;
+
+class EncryptionMigration implements IRepairStep {
+
+	/** @var IConfig */
+	private $config;
+	/** @var IManager */
+	private $manager;
+
+	public function __construct(IConfig $config,
+								IManager $manager) {
+		$this->config = $config;
+		$this->manager = $manager;
+	}
+
+	public function getName(): string {
+		return 'Check encryption key format';
+	}
+
+	private function shouldRun(): bool {
+		$versionFromBeforeUpdate = $this->config->getSystemValue('version', '0.0.0.0');
+		return version_compare($versionFromBeforeUpdate, '20.0.0.1', '<=');
+	}
+
+	public function run(IOutput $output): void {
+		if ($this->manager->isEnabled()) {
+			if ($this->config->getSystemValue('encryption.key_storage_migrated', '') === '') {
+				$this->config->setSystemValue('encryption.key_storage_migrated', false);
+			}
+		}
+	}
+}
diff --git a/lib/private/Server.php b/lib/private/Server.php
index a934628a047..9403aa9212b 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -348,7 +348,7 @@ class Server extends ServerContainer implements IServerContainer {
 				$c->getConfig()
 			);
 
-			return new Encryption\Keys\Storage($view, $util);
+			return new Encryption\Keys\Storage($view, $util, $c->getCrypto(), $c->getConfig());
 		});
 		/** @deprecated 20.0.0 */
 		$this->registerDeprecatedAlias('TagMapper', TagMapper::class);
diff --git a/tests/lib/Encryption/Keys/StorageTest.php b/tests/lib/Encryption/Keys/StorageTest.php
index bd9bbdecdf1..fdfa08d87c4 100644
--- a/tests/lib/Encryption/Keys/StorageTest.php
+++ b/tests/lib/Encryption/Keys/StorageTest.php
@@ -26,6 +26,8 @@ namespace Test\Encryption\Keys;
 use OC\Encryption\Keys\Storage;
 use OC\Files\View;
 use OCP\IConfig;
+use OCP\Security\ICrypto;
+use PHPUnit\Framework\MockObject\MockObject;
 use Test\TestCase;
 
 class StorageTest extends TestCase {
@@ -42,6 +44,9 @@ class StorageTest extends TestCase {
 	/** @var \PHPUnit\Framework\MockObject\MockObject */
 	protected $config;
 
+	/** @var MockObject|ICrypto */
+	protected $crypto;
+
 	protected function setUp(): void {
 		parent::setUp();
 
@@ -53,14 +58,53 @@ class StorageTest extends TestCase {
 			->disableOriginalConstructor()
 			->getMock();
 
+		$this->crypto = $this->createMock(ICrypto::class);
+		$this->crypto->method('encrypt')
+			->willReturnCallback(function ($data, $pass) {
+				return $data;
+			});
+		$this->crypto->method('decrypt')
+			->willReturnCallback(function ($data, $pass) {
+				return $data;
+			});
+
 		$this->config = $this->getMockBuilder(IConfig::class)
 			->disableOriginalConstructor()
 			->getMock();
 
-		$this->storage = new Storage($this->view, $this->util);
+		$this->storage = new Storage($this->view, $this->util, $this->crypto, $this->config);
 	}
 
 	public function testSetFileKey() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+		$this->util->expects($this->any())
+			->method('getUidAndFilename')
+			->willReturn(['user1', '/files/foo.txt']);
+		$this->util->expects($this->any())
+			->method('stripPartialFileExtension')
+			->willReturnArgument(0);
+		$this->util->expects($this->any())
+			->method('isSystemWideMountPoint')
+			->willReturn(false);
+
+		$data = json_encode(['key' => base64_encode('key')]);
+		$this->view->expects($this->once())
+			->method('file_put_contents')
+			->with($this->equalTo('/user1/files_encryption/keys/files/foo.txt/encModule/fileKey'),
+				$this->equalTo($data))
+			->willReturn(strlen($data));
+
+		$this->assertTrue(
+			$this->storage->setFileKey('user1/files/foo.txt', 'fileKey', 'key', 'encModule')
+		);
+	}
+
+	public function testSetFileOld() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.0');
 		$this->util->expects($this->any())
 			->method('getUidAndFilename')
 			->willReturn(['user1', '/files/foo.txt']);
@@ -70,6 +114,8 @@ class StorageTest extends TestCase {
 		$this->util->expects($this->any())
 			->method('isSystemWideMountPoint')
 			->willReturn(false);
+		$this->crypto->expects($this->never())
+			->method('encrypt');
 		$this->view->expects($this->once())
 			->method('file_put_contents')
 			->with($this->equalTo('/user1/files_encryption/keys/files/foo.txt/encModule/fileKey'),
@@ -98,6 +144,9 @@ class StorageTest extends TestCase {
 	 * @param string $expectedKeyContent
 	 */
 	public function testGetFileKey($path, $strippedPartialName, $originalKeyExists, $expectedKeyContent) {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
 		$this->util->expects($this->any())
 			->method('getUidAndFilename')
 			->willReturnMap([
@@ -118,6 +167,11 @@ class StorageTest extends TestCase {
 			->with($this->equalTo('/user1/files_encryption/keys' . $strippedPartialName . '/encModule/fileKey'))
 			->willReturn($originalKeyExists);
 
+		$this->crypto->method('decrypt')
+			->willReturnCallback(function ($data, $pass) {
+				return $data;
+			});
+
 		if (!$originalKeyExists) {
 			$this->view->expects($this->at(1))
 				->method('file_exists')
@@ -127,12 +181,12 @@ class StorageTest extends TestCase {
 			$this->view->expects($this->once())
 				->method('file_get_contents')
 				->with($this->equalTo('/user1/files_encryption/keys' . $path . '/encModule/fileKey'))
-				->willReturn('key2');
+				->willReturn(json_encode(['key' => base64_encode('key2')]));
 		} else {
 			$this->view->expects($this->once())
 				->method('file_get_contents')
 				->with($this->equalTo('/user1/files_encryption/keys' . $strippedPartialName . '/encModule/fileKey'))
-				->willReturn('key');
+				->willReturn(json_encode(['key' => base64_encode('key')]));
 		}
 
 		$this->assertSame($expectedKeyContent,
@@ -141,6 +195,10 @@ class StorageTest extends TestCase {
 	}
 
 	public function testSetFileKeySystemWide() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
 		$this->util->expects($this->any())
 			->method('getUidAndFilename')
 			->willReturn(['user1', '/files/foo.txt']);
@@ -150,11 +208,18 @@ class StorageTest extends TestCase {
 		$this->util->expects($this->any())
 			->method('stripPartialFileExtension')
 			->willReturnArgument(0);
+
+		$this->crypto->method('encrypt')
+			->willReturnCallback(function ($data, $pass) {
+				return $data;
+			});
+
+		$data = json_encode(['key' => base64_encode('key')]);
 		$this->view->expects($this->once())
 			->method('file_put_contents')
 			->with($this->equalTo('/files_encryption/keys/files/foo.txt/encModule/fileKey'),
-				$this->equalTo('key'))
-			->willReturn(strlen('key'));
+				$this->equalTo($data))
+			->willReturn(strlen($data));
 
 		$this->assertTrue(
 			$this->storage->setFileKey('user1/files/foo.txt', 'fileKey', 'key', 'encModule')
@@ -162,6 +227,10 @@ class StorageTest extends TestCase {
 	}
 
 	public function testGetFileKeySystemWide() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
 		$this->util->expects($this->any())
 			->method('getUidAndFilename')
 			->willReturn(['user1', '/files/foo.txt']);
@@ -174,7 +243,7 @@ class StorageTest extends TestCase {
 		$this->view->expects($this->once())
 			->method('file_get_contents')
 			->with($this->equalTo('/files_encryption/keys/files/foo.txt/encModule/fileKey'))
-			->willReturn('key');
+			->willReturn(json_encode(['key' => base64_encode('key')]));
 		$this->view->expects($this->once())
 			->method('file_exists')
 			->with($this->equalTo('/files_encryption/keys/files/foo.txt/encModule/fileKey'))
@@ -186,11 +255,19 @@ class StorageTest extends TestCase {
 	}
 
 	public function testSetSystemUserKey() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
+		$data = json_encode([
+			'key' => base64_encode('key'),
+			'uid' => null]
+		);
 		$this->view->expects($this->once())
 			->method('file_put_contents')
 			->with($this->equalTo('/files_encryption/encModule/shareKey_56884'),
-				$this->equalTo('key'))
-			->willReturn(strlen('key'));
+				$this->equalTo($data))
+			->willReturn(strlen($data));
 
 		$this->assertTrue(
 			$this->storage->setSystemUserKey('shareKey_56884', 'key', 'encModule')
@@ -198,11 +275,19 @@ class StorageTest extends TestCase {
 	}
 
 	public function testSetUserKey() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
+		$data = json_encode([
+			'key' => base64_encode('key'),
+			'uid' => 'user1']
+		);
 		$this->view->expects($this->once())
 			->method('file_put_contents')
 			->with($this->equalTo('/user1/files_encryption/encModule/user1.publicKey'),
-				$this->equalTo('key'))
-			->willReturn(strlen('key'));
+				$this->equalTo($data))
+			->willReturn(strlen($data));
 
 		$this->assertTrue(
 			$this->storage->setUserKey('user1', 'publicKey', 'key', 'encModule')
@@ -210,10 +295,18 @@ class StorageTest extends TestCase {
 	}
 
 	public function testGetSystemUserKey() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
+		$data = json_encode([
+			'key' => base64_encode('key'),
+			'uid' => null]
+		);
 		$this->view->expects($this->once())
 			->method('file_get_contents')
 			->with($this->equalTo('/files_encryption/encModule/shareKey_56884'))
-			->willReturn('key');
+			->willReturn($data);
 		$this->view->expects($this->once())
 			->method('file_exists')
 			->with($this->equalTo('/files_encryption/encModule/shareKey_56884'))
@@ -225,10 +318,18 @@ class StorageTest extends TestCase {
 	}
 
 	public function testGetUserKey() {
+		$this->config->method('getSystemValue')
+			->with('version')
+			->willReturn('20.0.0.2');
+
+		$data = json_encode([
+			'key' => base64_encode('key'),
+			'uid' => 'user1']
+		);
 		$this->view->expects($this->once())
 			->method('file_get_contents')
 			->with($this->equalTo('/user1/files_encryption/encModule/user1.publicKey'))
-			->willReturn('key');
+			->willReturn($data);
 		$this->view->expects($this->once())
 			->method('file_exists')
 			->with($this->equalTo('/user1/files_encryption/encModule/user1.publicKey'))
@@ -516,7 +617,7 @@ class StorageTest extends TestCase {
 	 */
 	public function testBackupUserKeys($createBackupDir) {
 		$storage = $this->getMockBuilder('OC\Encryption\Keys\Storage')
-			->setConstructorArgs([$this->view, $this->util])
+			->setConstructorArgs([$this->view, $this->util, $this->crypto, $this->config])
 			->setMethods(['getTimestamp'])
 			->getMock();
 
diff --git a/version.php b/version.php
index 9df6d8fbecc..7f4d76bea22 100644
--- a/version.php
+++ b/version.php
@@ -29,7 +29,7 @@
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
 
-$OC_Version = [20, 0, 0, 1];
+$OC_Version = [20, 0, 0, 2];
 
 // The human readable string
 $OC_VersionString = '20.0.0 alpha';