What is the best way to handle toll free bridging ...

# ios

[Landry Norris]

What is the best way to handle toll free bridging in Kotlin/Native? I have a method that returns NSData, and I need to pass this to a method that accepts CFDataRef. These types can be toll free bridged, but I can’t figure out how to do so in Kotlin, since casting doesn’t work.

[russhwolf]

You can use CFBridgingRetain to convert NSData to CFDataRef, and CFBridgingRelease to go the other way. Note that you can create memory leaks if you retain things without releasing them via either CFBridgingRelease or CFRelease.

[russhwolf]

I do some of this in Multiplatform Settings if you want an example https://github.com/russhwolf/multiplatform-settings/blob/master/multiplatform-settings/src/appleMain/kotlin/com/russhwolf/settings/KeychainSettings.kt

[Landry Norris]

Thanks. It seems like the secure enclave library is accepting the data now. Now I just have to figure out why the query returns no key found right after I create the key... Good to know that the bridging is working, though.

[Landry Norris]

I see you're actually using the same secure key library. I'll have to look more through the code.

[russhwolf]

Make sure you're checking the status codes you get back. Lots of subtle little errors that can happen if you pass the wrong arguments to some of those functions.

[Landry Norris]

I just got it to a point where I can read the text errors from the generate key pair method (not that they were as helpful as I'd hoped) and fixed the -50 telling me the params were wrong. Now the key gen method returns success, but the query returns -25300 (not found). I'll have to spend some more time debugging it later.

[Landry Norris]

The CFDictionary params are a bit frustrating. It's times like this when I remember why I stopped developing for iOS a few years back with my side projects. KMM's got me wanting to get back into iOS dev, though.

[russhwolf]

Yeah every interaction with CoreFoundation is like some eldritch incantation.

[phldavies]

https://github.com/russhwolf/multiplatform-settings/issues/79#issuecomment-782758786 not sure if this is relevant to your -50 error 😉