Adapt code to new encryption system

fileKey gets deleted upon save as it’s stored in shareKeys instead now.
We use presence of a fileKey to detect if a file is using the legacy
 system or the new one, because we do not always have access to header
 data.

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

1 files changed, 12 insertions, 6 deletions

diff --git a/apps/encryption/lib/KeyManager.php b/apps/encryption/lib/KeyManager.php
index 5f35f7a8422..5c933b5f8b2 100644
--- a/apps/encryption/lib/KeyManager.php
+++ b/apps/encryption/lib/KeyManager.php
@@ -440,18 +440,19 @@ class KeyManager {
 	/**
 	 * @param string $path
 	 * @param $uid
+	 * @param ?bool $useLegacyFileKey null means try both
 	 * @return string
 	 */
-	public function getFileKey(string $path, ?string $uid, bool $useLegacyFileKey): string {
+	public function getFileKey(string $path, ?string $uid, ?bool $useLegacyFileKey): string {
 		if ($uid === '') {
 			$uid = null;
 		}
 		$publicAccess = is_null($uid);
-
-		if ($useLegacyFileKey) {
+		$encryptedFileKey = '';
+		if ($useLegacyFileKey ?? true) {
 			$encryptedFileKey = $this->keyStorage->getFileKey($path, $this->fileKeyId, Encryption::ID);
 
-			if (empty($encryptedFileKey)) {
+			if (empty($encryptedFileKey) && $useLegacyFileKey) {
 				return '';
 			}
 		}
@@ -477,13 +478,14 @@ class KeyManager {
 			$privateKey = $this->session->getPrivateKey();
 		}
 
-		if ($useLegacyFileKey) {
+		if ($useLegacyFileKey ?? true) {
 			if ($encryptedFileKey && $shareKey && $privateKey) {
 				return $this->crypt->multiKeyDecryptLegacy($encryptedFileKey,
 					$shareKey,
 					$privateKey);
 			}
-		} else {
+		}
+		if ($useLegacyFileKey ?? false) {
 			if ($shareKey && $privateKey) {
 				return $this->crypt->multiKeyDecrypt($shareKey, $privateKey);
 			}
@@ -664,6 +666,10 @@ class KeyManager {
 		return $this->keyStorage->deleteAllFileKeys($path);
 	}
 
+	public function deleteLegacyFileKey(string $path): bool {
+		return $this->keyStorage->deleteFileKey($path, $this->fileKeyId, Encryption::ID);
+	}
+
 	/**
 	 * @param array $userIds
 	 * @return array