Store signature on metadata save

And send it back in a header on request. Signed-off-by: Louis Chemineau <[email protected]>
nextcloud · Jul 3, 2023 · c6d6c5f · c6d6c5f
1 parent e1a97e5
commit c6d6c5f
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Showing 3 changed files with 40 additions and 1 deletion.
diff --git a/lib/Controller/MetaDataController.php b/lib/Controller/MetaDataController.php
@@ -92,7 +92,11 @@ public function getMetaData(int $id, ?string $shareToken = null): DataResponse {
 			$this->logger->critical($e->getMessage(), ['exception' => $e, 'app' => $this->appName]);
 			throw new OCSBadRequestException($this->l10n->t('Cannot read metadata'));
 		}
-		return new DataResponse(['meta-data' => $metaData]);
+		return new DataResponse(
+			['meta-data' => $metaData],
+			Http::STATUS_OK,
+			['X-NC-E2EE-SIGNATURE' => $this->metaDataStorage->getSignature($id)],
+		);
 	}
 
 	/**

diff --git a/lib/IMetaDataStorage.php b/lib/IMetaDataStorage.php
@@ -69,6 +69,14 @@ public function updateMetaDataIntoIntermediateFile(string $userId, int $id, stri
 	 */
 	public function saveIntermediateFile(string $userId, int $id): void;
 
+	/**
+	 * Get the stored signature
+	 *
+	 * @throws NotPermittedException
+	 * @throws NotFoundException
+	 */
+	public function getSignature(int $id): string;
+
 	/**
 	 * Delete the previously set intermediate file
 	 *

diff --git a/lib/MetaDataStorage.php b/lib/MetaDataStorage.php
@@ -45,6 +45,7 @@ class MetaDataStorage implements IMetaDataStorage {
 	private string $metaDataRoot = '/meta-data';
 	private string $metaDataFileName = 'meta.data';
 	private string $intermediateMetaDataFileName = 'intermediate.meta.data';
+	private string $metaDataSignatureFileName = 'meta.data.signature';
 
 	public function __construct(IAppData $appData,
 								IRootFolder $rootFolder) {
@@ -195,9 +196,35 @@ public function saveIntermediateFile(string $userId, int $id): void {
 			$intermediateMetaDataFile->delete();
 		}
 
+		// Save signature alongside the metadata.
+		// It will be send in a header on metadata request for the client to check.
+		$this->saveSignature($id, json_decode($intermediateMetaDataFile->getContent(), true)['signature']);
+
 		$this->cleanupLegacyFile($userId, $id);
 	}
 
+	private function saveSignature(int $id, string $signature): void {
+		$folderName = $this->getFolderNameForFileId($id);
+		$dir = $this->appData->getFolder($folderName);
+
+		try {
+			$signatureFile = $dir->getFile($this->metaDataSignatureFileName);
+		} catch (NotFoundException $ex) {
+			$signatureFile = $dir->newFile($this->metaDataSignatureFileName);
+		}
+
+		$signatureFile->putContent($signature);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getSignature(int $id): string {
+		$folderName = $this->getFolderNameForFileId($id);
+		$dir = $this->appData->getFolder($folderName);
+		return $dir->getFile($this->metaDataSignatureFileName)->getContent()();
+	}
+
 	/**
 	 * @inheritDoc
 	 */