Allow to share only to e2e enabled users

[tobiasKaminsky]

For our new e2e sharing it would be great that clients can directly query for users that have e2e setup already.
Otherwise users would see all sharees, select one and then get message that e2e is not set up for them and thus sharing is not possible.

route: ocs/v2.php/apps/files_sharing/api/v1/sharees
extra parameter could be: e2e user: yes/no

We have in our e2e app already a way to check if public key exists:
https://github.com/nextcloud/end_to_end_encryption/blob/master/lib/Capabilities.php#L48

So if this is true, then this user can be shown.

It would be great to have this in NC26, as we then can same quite some work on our clients.
If not, please tell us soon, so that we can prepare for it.
Either way, I think this should be done, even after NC26 as this is a way better UX.

@AndyScherzinger (as "team lead")

[AndyScherzinger]

@artonge What do you think? Low effort and doable for 26 or rather post-v26 initial release timeframe?

[artonge]

Sharee API is not designed to support such information, neither in input nor output. This will require some changes, like a plugin system or something. So I would say post 26 as we are already past feature freeze.

Possible solution:

• Extend the Collaborators API, so we can include arbitrary "metadata" in the response, in our case whether e2ee is set up.
  Might actually require no changes, as it seem like there is no strict format.

• Create a plugin system in the backend to allow apps to add to this metadata.
  Here:
  

  server/lib/private/Collaboration/Collaborators/Search.php

  Lines 65 to 74 in 5a48768

  	foreach ($shareTypes as $type) {
  	if (!isset($this->pluginList[$type])) {
  	continue;
  	}
  	foreach ($this->pluginList[$type] as $plugin) {
  	/** @var ISearchPlugin $searchPlugin */
  	$searchPlugin = $this->c->resolve($plugin);
  	$hasMoreResults = $searchPlugin->search($search, $limit, $offset, $searchResult) || $hasMoreResults;
  	}
  	}

  
  Or maybe here:
  

  server/lib/private/Collaboration/Collaborators/SearchResult.php

  Lines 37 to 48 in 5a48768

  	public function addResultSet(SearchResultType $type, array $matches, array $exactMatches = null) {
  	$type = $type->getLabel();
  	if (!isset($this->result[$type])) {
  	$this->result[$type] = [];
  	$this->result['exact'][$type] = [];
  	}
  	$this->result[$type] = array_merge($this->result[$type], $matches);
  	if (is_array($exactMatches)) {
  	$this->result['exact'][$type] = array_merge($this->result['exact'][$type], $exactMatches);
  	}
  	}

• Create a plugin system in the frontend to allow apps to tweak the rendering of the results.
  

  server/apps/files_sharing/src/components/SharingInput.vue

  Lines 222 to 229 in 5a48768

  	const exactSuggestions = this.filterOutExistingShares(rawExactSuggestions)
  	.map(share => this.formatForMultiselect(share))
  	// sort by type so we can get user&groups first...
  	.sort((a, b) => a.shareType - b.shareType)
  	const suggestions = this.filterOutExistingShares(rawSuggestions)
  	.map(share => this.formatForMultiselect(share))
  	// sort by type so we can get user&groups first...
  	.sort((a, b) => a.shareType - b.shareType)

[tobiasKaminsky]

@artonge

So I would say post 26 as we are already past feature freeze.

If you would be allowed to work on it for NC26, would it be ready by then?
How much time does it roughly costs?
As otherwise 3 devs need to implement the old mechanism, and then after NC26 add new mechanism and maintain both system until NC26 is deprecated (5 years after enterprise release).

[artonge]

I would like to discuss the approach first, but a solution based on my initial comment would take at least a week. A bit more with reviews and such.