Make Compatible with App Extensions

[mmcguill]

It would be very useful to include this library in App Extensions (my use case in particular is Password AutoFill extensions).

Currently if you try to build this library in an App Extension context you will get build errors related to the use of NFC (NFC access is not available to App Extensions).

A concrete example looks like this:

While there may be no possibility of using a YubiKey over NFC in an App Extension (Password Auto Fill mode), it should in theory be possible to use the new 5Ci over Lightning in this context, so it would be great if this library would compile that functionality while excluding the NFC functionality when built as an App Extension.

Thanks!

[jensutbult]

At the moment I think the only solution is for you to fork the SDK and remove all references to NFC and parts of UIKit not supported by an Autofill Credential Provider extension. The forked SDK will be used in your extension and our SDK for the normal app. In the future we might build a specific SDK for use in an extension but this is not planned for now.

[mmcguill]

OK, thanks for the response. It's a less than ideal situation obviously :(

[imakhalova]

My guess that App Extension will not support communication with External Accessory framework. Even if you remove NFC support out of SDK. For quick test you could actually take old version of SDK which didn't support NFC (2.0.1) and check whether you can detect device connection and exchange any data with device. At least you will know whether it worth your efforts in forking of this repo.

[mmcguill]

Thanks @imakhalova - There's no indication in the documentation that it won't work in App Extension context but of course worth a test. I've not been able to find anything online about this working either.

[strongbox-mark]

Hi there, has there been a decision made on support for App Extensions?

A lot of iOS users would like to use their YubiKeys in AutoFill mode.

Thanks,
-Mark

[jensutbult]

As of now we're focusing on wrapping up the 4.0 release of the SDK and adding PIV support. Once that is done we will prioritise the next set of features to implement. We will bring this issue into that process. In the meantime I would suggest simply forking the SDK and hacking away removing the parts not supported by the App Extension. It's probably not more than a few hours of boring work but it will solve your issue and if it works will be valuable feedback for us when we decide on the next features to implement in the SDK.

[strongbox-mark]

I'm afraid that's not something I think I want to take on...

Shouldn't we keep this issue open? Your call totally of course.

Also, is there anyone you could ping about Yubico/yubikey-personalization#173 ?