Proguard removes jdk providers

[acmpo6ou]

Hello.

I have a KMP project with Desktop and Android as target OSes. I have this in my dependencies (the latest 4.0.0 version):

implementation(libs.cryptography.core)
implementation(libs.cryptography.provider.jdk)

I'm using ProGuard:

compose.desktop {
    application {
        // ...
        buildTypes.release.proguard {
            obfuscate = true
        }
    }
}

If I compile a release uber jar:

./gradlew packageReleaseUberJarForCurrentOS

Running it will result in this error message (the app doesn't crash, but the decryption doesn't happen either):

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: No providers registered. Please provide a dependency or register provider explicitly
	at dev.whyoleg.cryptography.e.b(Unknown Source)
	at kotlin.SynchronizedLazyImpl.getValue(Unknown Source)
	at d.d.e.k.a(Unknown Source)
	at d.d.e.k.a(Unknown Source)
	at d.d.e.p.invokeSuspend(Unknown Source)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(Unknown Source)
	at kotlinx.coroutines.W.run(Unknown Source)
	at kotlinx.coroutines.c.a.a(Unknown Source)
	at kotlinx.coroutines.c.d.run(Unknown Source)
	Suppressed: kotlinx.coroutines.internal.h: [CoroutineName(d.d.e.a:d.d.e.k:default), aU{Cancelling}@2ab8b3b7, Dispatchers.Main]

The debug build works perfectly fine, as well as a release build for Android.

To fix the above issue, I had to add this to my proguard file (compose-desktop.pro):

-keep class dev.whyoleg.cryptography.*
-keep class dev.whyoleg.cryptography.providers.jdk.*

and this to my build.gradle.kts:

compose.desktop {
    application {
        // ...
        buildTypes.release.proguard {
            obfuscate = true
            configurationFiles.from(project.file("compose-desktop.pro"))
        }
    }
}

[whyoleg]

Hey!
Thanks for filling the issue, yeah, we will need to provide pro guard rules for the library out of the box, similar to have it's done in kotlinx.coroutines or similar.
The reason for this, is that providers are loaded via JDK ServiceLoader, and so class name is important.

Additionally integration test will need to be added

[whyoleg]

Okay, after reading Kotlin/kotlinx.coroutines#4025, it looks like it's currently not possible to include proguard rules for the desktop JVM.
As it works fine on Android, I don't think it's possible to do anything here except to add some documentation that the library is using ServiceLoader and an example of Proguard rules.
So I will monitor the situation, and if something changes, I will implement it.
Let's keep the issue open, so that the issue will be easier to find for others.