Add ZIP file Support (ZIP/UNZIP)

[Mannshoch]

Expected behaviour

• Allow to ZIP and UNZIP Files/Directories
• A ZIPed File/Directory should replace these which itself should be listed as old Version.
• ZIP File should opens like a normal directory and allow to move files in and out of it

Actual behaviour

I get a download dialog

[MorrisJobke]

@LukasReschke We had this and removed it because of security reasons, right?

[Mannshoch]

security reason? WHAT?

[LukasReschke]

@LukasReschke We had this and removed it because of security reasons, right?

Yes. At the time being there was no sane library that:

1. Did not easily DoS the server (you don't want to have someone open a ZIP bomb etc.)
2. Was implemented in a way that it didn't disclose arbitrary files on the server. I'd rather prefer a small ZIP library that doesn't necessarily follow the standard 100% but excludes every potential insecure thing :-)

If someone wants to work on that and has a secure library in mind. Pull requests are always welcome. 😉 – Or an app on apps.nextcloud.com :-)

[Mannshoch]

LOL. Bombs got Digital. Thats strange. Even more that this seems to be an old security problem.

[Happyfeet01]

Is this still an security problem? I have many zip files on my server.

[virtualdxs]

It should be implemented but with a security option. I'm migrating between nextcloud servers and this would be very helpful - I can download a folder as a zipfile but I can't upload it as such.

[emresaracoglu]

Is there a new plan in this regard?

[virtualdxs]

Another idea, do you see any potential problems in a plain tar archive? There's no compression so no zip bomb vector, but it still makes dealing with moving folders exponentially easier. I think zip would still be better because of size and cross-platform compatibility (my stance is still that it should be implemented, disabled by default, and have a checkbox to turn it on preceded by a security warning), but tar would be better than nothing.

Also, another possibility would be to read the uncompressedSize, compare that to the user's remaining space, and start writing, and if it either a. exceeds its uncompressedSize by more than a small margin or b. exceeds the user's available space, regardless of any margin, it stops writing, deletes what it's written so far, and throws an error.

[Yetangitu]

I got a feature request for an app to allow individual file access from archive files. I feel this feature should really be implemented in core as that already does file access abstraction for apps. I do not see security issues with read-only access so that should be implementable without problems. Given the abundance of archive file formats a generic archive abstraction layer would be more useful than individual zip/tar/7z/whatnot features.

With regard to the danger of 'zip bombs' I'd say that user quota could be used to guard against them? Just don't allow the extracted file to go over the set quota and the temporary 'damage' would be confined to a single user's max allowed file space. Temporary as the extracted files would be deleted on reaching the quota before finishing the extraction - there is no use in keeping those around after all.

[sunjam]

Here is a link to the feature request that @Yetangitu mentioned.

Here is a different zip feature request for adding the ability to upload folders via file drop by zipping them into an archive if they would otherwise fail.