User entered credentials can only be set from the web UI

[juliushaertl]

• Setup an external storage that uses "User entered, stored in database" credentials
• Never access the external storage though the web interface
• Try to open it on mobile/desktop clients

The web UI checks if credentials still need to be provided in the mount point status coming form ocs/v2.php/apps/files_external/api/v1/mounts?format=json. If that is the case the credentials are asked in a modal and sent back to the server for storing them: https://github.com/nextcloud/server/blob/f63156976bd647607bd81f2b99786fd7d79ddf7c/apps/files_external/js/statusmanager.js#L389-L427

We ideally should have an OCS API that allows the clients to also implement such a credential dialog.

I would consider this more as an enhancement and document this limitation for now.

Steps to take

• [ ] Server: Implement OCS API to store user defined credentials per mountpoint
• [ ] Android @tobiasKaminsky
• [ ] Desktop @er-vin
• [ ] iOS @marinofaggiana

cc @rullzer

[tobiasKaminsky]

Clients are doing "only" propfind for folders, which might have this external storage as subfolder. Do you really check on each and every folder listing "if credentials still need to be provided in the mount point status"? I think this is too much and should be some sort of error code in propfind return, e.g."credentials missing" and then we can react upon this.

[juliushaertl]

I'll need to look into that a bit more in detail, but indeed it would make sense to somehow already provide the status "credentials missing" in the propfind response.