Moving a lot of encrypted files makes them unaccessible

[yahesh]

Expected behaviour

When moving a large amount of server-side encrypted files from one shared folder to another shared folder all those files should be accessible afterwards.

Actual behaviour

When moving a large amount of server-side encrypted files from one shared folder to another shared folder it happened that files got broken with Bad Signature error messages popping up in the nextcloud.log file.

Steps to reproduce

1. Move a bigger folder (e.g. 700mb) from one server-side encrypted shared folder to another server-side encrypted shared folder on your Mac.
2. Wait for the sync client to start the syncing process.
3. Try to access the moved files as another user after the sync has been completed.

Client configuration

Client version: Mac Sync Client Version 2.5.1final (build 20181204).

Operating system: macOS 10.13.6 (17G5019)

OS language: German

Installation path of client: /Applications/nextcloud.app

Server configuration

Operating system: Ubuntu 16.04 LTS

Web server: Apache/2.4.38 (Ubuntu)

Database: MySQL Ver 14.14 Distrib 5.6.43-84.3, for debian-linux-gnu (x86_64) using 6.3

PHP version: PHP 7.2.16-1+ubuntu16.04.1+deb.sury.org+1

Nextcloud version: 15.0.5

Storage backend (external storage): NFS

[yahesh]

Is there any update on this? This still breaks files.

[yahesh]

This seems to be related to: nextcloud/server#16419

[yahesh]

As we've seen, Nextcloud 16.0.3 introduced the configuration value encryption_skip_signature_check which - when activated - allows the Nextcloud web GUI to access the files again. However, downloading or syncing the broken files still does not work.

We tested this on a test installation with 2000 identical pictures. One part of the problem seems to be that the files have to be moved from/to/between shared folders.