Merge pull request #56573 from nextcloud/backport/56515/stable32

[stable32] Encode s3 metadata as base64 if needed

Author: AndyScherzinger

lib/private/Files/ObjectStore/S3.php

@@ -100,6 +100,9 @@ private function parseS3Metadata(array $metadata): array {
 		$result = [];
 		foreach ($metadata as $key => $value) {
 			if (str_starts_with($key, 'x-amz-meta-')) {
+				if (str_starts_with($value, 'base64:')) {
+					$value = base64_decode(substr($value, 7));
+				}
 				$result[substr($key, strlen('x-amz-meta-'))] = $value;
 			}
 		}

lib/private/Files/ObjectStore/S3ObjectTrait.php

@@ -82,7 +82,11 @@ public function readObject($urn) {
 	private function buildS3Metadata(array $metadata): array {
 		$result = [];
 		foreach ($metadata as $key => $value) {
-			$result['x-amz-meta-' . $key] = $value;
+			if (mb_check_encoding($value, 'ASCII')) {
+				$result['x-amz-meta-' . $key] = $value;
+			} else {
+				$result['x-amz-meta-' . $key] = 'base64:' . base64_encode($value);
+			}
 		}
 		return $result;
 	}