android-aes-gcm-key-gen.kt

fun generateAesKey(): SecretKey {
    val keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")
    val kgps = KeyGenParameterSpec.Builder("my_aes_key", KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
        .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
        // This is required to be able to provide the IV ourselves
        .setRandomizedEncryptionRequired(false)
        .build()
    keyGenerator.init(kgps)
    return keyGenerator.generateKey()
}