Secured Android SharedPreferences Error: 'Caused by: java.lang.RuntimeException: Field keySize_ for...' - security

Question

In an Android Kotlin project, I implemented EncryptedSharedPreference feature based on this link using the androidx.security library and it worked well in debug mode. But in release mode, I keep getting this error
java.lang.ExceptionInInitializerError
at com.package_name.i.a.f(:46)
at com.package_name.i.a.j(:52)
at com.package_name.i.a.e(:82)
at com.package_name.MyApplication.onCreate(:37)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1013)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4707)
at android.app.ActivityThread.-wrap1(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1405)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.RuntimeException: Field keySize_ for k.a.d.a.h0.u not found. Known fields are [private int k.a.d.a.h0.u.i, private static final k.a.d.a.h0.u k.a.d.a.h0.u.j, private static volatile k.a.d.a.i0.a.a1 k.a.d.a.h0.u.k]
at k.a.d.a.i0.a.v0.n0(:608)
Please kindly share your ideas on how to solve this error.

Answer 1

This bug is related to Minify Enabled, which most likely causes some values to be removed.
A bug is reported already, you can track it here:
https://issuetracker.google.com/issues/157983099

Answer 2

-keep class com.google.crypto.** { *; }

Answer 3

Something is wrong with the rc2 version of android crypto of may 20. So it is better to use 1.0.0-alpha02 in your gradle file.
Remember, takes care with dependencies which are not in rc. You can also fix the issue with a proguard rules (see comment of Sebas LG).
dependencies {
implementation "androidx.security:security-crypto:1.0.0-alpha02"
}
Official documentation : https://developer.android.com/jetpack/androidx/releases/security
Linked commits : https://android.googlesource.com/platform/frameworks/support/+log/f66cdf1658639bd74ae850dfe3c1f5bb72eaebe6..6be101c2241593fee3ef9ab4e1fb337b485f2f9a/security/crypto

Answer 4

I solved using
dependencies {
..
implementation "androidx.security:security-crypto:1.0.0-rc03"

Answer 5

This is due to the fact that AndroidX security library uses the Google Tink library(This is already fixed in Tink 1.4.0), where there is a flaw in working with Proguard.
Add this code to proguard-rules.pro and this should help:
-keepclassmembers class * extends com.google.crypto.tink.shaded.protobuf.GeneratedMessageLite {
<fields>;
}
Links:
https://github.com/google/tink/issues/361
https://github.com/google/tink/blob/master/java_src/src/main/resources/META-INF/proguard/protobuf.pro