Including cryptography-kotlin changes the minos and sdk of the KMP iOS framework to 14.0

[lyamamot]

Before including this library as a dependency, the minos and sdk of my project's KMP iOS framework were 13.0 and 18.0, respectively. After including this library, they are both set to 14.0.

This caused an error while submitting the app to the App Store because the XCFramework container for the framework was declaring compatibility back to iOS 13.0 but the included framework was set to a minimum of 14.0. This can be worked around by setting the MinimumOSVersion in the XCFramework in the KMP shared library's build.gradle.kts:

kotlin {
    listOf(
        iosArm64(),
        iosSimulatorArm64(),
    ).forEach {
        it.binaries.framework {
            // Set minimum iOS version of shared library for compatibility with dependencies, such as cryptography-kotlin.
            freeCompilerArgs +=
                listOf(
                    "-Xoverride-konan-properties=osVersionMin.ios_simulator_arm64=$minimumIosVersion;osVersionMin.ios_arm64=$minimumIosVersion;osVersionMin.ios_x64=$minimumIosVersion",
                )

However, I'm wondering about two things:

1. Now that sdk is set to 14.0, is the framework being built with the iOS 14 SDK instead of iOS 18 and/or will this cause problems in the future if I need to bump my minimum version above 14.0?
2. Should this requirement to have a minimum version of 14.0 be documented?

I've created a small reproducer project here: https://github.com/lyamamot/cryptography-dependency-changes-minos-reproduce

[whyoleg]

Thanks for the reproducer!
The issue comes down to the fact that CryptoKit based provider uses interop with Swift, which sets those explicitly during building (here). Not sure if that's possible to override those back on the user side...
And the cryptokit provider is used by default when optimal provider is used.
If you don't need to support AES-GCM or ECDH on iOS, you can try adding just the apple provider.
In any case, I will try to fix this somehow in the next major release, but I'm not sure it will be soon. I will take a look to see if it's possible to fix this in a patch release at this point.
Also, you might be interested in "https://youtrack.jetbrains.com/issue/KT-80620/Bump-minimal-iOS-and-tvOS-supported-versions-to-14.0"