feat(transfer-ownership): Correctly react to encrypted files

For E2EE encrypted files, we abort the transfer.
For SSE encrypted files, we abort only if not using master key.
Also fixed the check for when the path to a single file is used.

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

apps/files/lib/Service/OwnershipTransferService.php

@@ -204,7 +204,7 @@ class OwnershipTransferService {
 	/**
 	 * @param OutputInterface $output
 	 *
-	 * @throws \Exception
+	 * @throws TransferOwnershipException
 	 */
 	protected function analyse(string $sourceUid,
 		string $destinationUid,
@@ -212,33 +212,56 @@ class OwnershipTransferService {
 		View $view,
 		OutputInterface $output): void {
 		$output->writeln('Validating quota');
-		$size = $view->getFileInfo($sourcePath, false)->getSize(false);
+		$sourceFileInfo = $view->getFileInfo($sourcePath, false);
+		if ($sourceFileInfo === false) {
+			throw new TransferOwnershipException("Unknown path provided: $sourcePath", 1);
+		}
+		$size = $sourceFileInfo->getSize(false);
 		$freeSpace = $view->free_space($destinationUid . '/files/');
 		if ($size > $freeSpace && $freeSpace !== FileInfo::SPACE_UNKNOWN) {
-			$output->writeln('<error>Target user does not have enough free space available.</error>');
-			throw new \Exception('Execution terminated.');
+			throw new TransferOwnershipException('Target user does not have enough free space available.', 1);
 		}
 
 		$output->writeln("Analysing files of $sourceUid ...");
 		$progress = new ProgressBar($output);
 		$progress->start();
 
+		if ($this->encryptionManager->isEnabled()) {
+			$masterKeyEnabled = \OCP\Server::get(\OCA\Encryption\Util::class)->isMasterKeyEnabled();
+		} else {
+			$masterKeyEnabled = false;
+		}
 		$encryptedFiles = [];
-		$this->walkFiles($view, $sourcePath,
-			function (FileInfo $fileInfo) use ($progress, &$encryptedFiles) {
-				if ($fileInfo->getType() === FileInfo::TYPE_FOLDER) {
-					// only analyze into folders from main storage,
-					if (!$fileInfo->getStorage()->instanceOfStorage(IHomeStorage::class)) {
-						return false;
-					}
-					return true;
-				}
-				$progress->advance();
-				if ($fileInfo->isEncrypted()) {
-					$encryptedFiles[] = $fileInfo;
-				}
-				return true;
-			});
+		if ($sourceFileInfo->getType() === FileInfo::TYPE_FOLDER) {
+			if ($sourceFileInfo->isEncrypted()) {
+				/* Encrypted folder means e2ee encrypted */
+				$encryptedFiles[] = $sourceFileInfo;
+			} else {
+				$this->walkFiles($view, $sourcePath,
+					function (FileInfo $fileInfo) use ($progress, $masterKeyEnabled, &$encryptedFiles) {
+						if ($fileInfo->getType() === FileInfo::TYPE_FOLDER) {
+							// only analyze into folders from main storage,
+							if (!$fileInfo->getStorage()->instanceOfStorage(IHomeStorage::class)) {
+								return false;
+							}
+							if ($fileInfo->isEncrypted()) {
+								/* Encrypted folder means e2ee encrypted */
+								$encryptedFiles[] = $fileInfo;
+							}
+							return true;
+						}
+						$progress->advance();
+						if ($fileInfo->isEncrypted() && !$masterKeyEnabled) {
+							/* Encrypted file means SSE, we only care if we are using user keys */
+							$encryptedFiles[] = $fileInfo;
+						}
+						return true;
+					});
+			}
+		} elseif ($sourceFileInfo->isEncrypted() && !$masterKeyEnabled) {
+			/* Encrypted file means SSE, we only care if we are using user keys */
+			$encryptedFiles[] = $sourceFileInfo;
+		}
 		$progress->finish();
 		$output->writeln('');
 
@@ -249,7 +272,7 @@ class OwnershipTransferService {
 				/** @var FileInfo $encryptedFile */
 				$output->writeln('  ' . $encryptedFile->getPath());
 			}
-			throw new \Exception('Execution terminated.');
+			throw new TransferOwnershipException('Some files are encrypted - please decrypt them first.', 1);
 		}
 	}