Returns the db key

get_char_key.kt

/**
 * Returns the database key suitable for using with Room.
 *
 * @param passcode the user's passcode
 * @param context the caller's context
 */
fun getCharKey(passcode: CharArray, context: Context): CharArray {
    if (dbCharKey == null) {
        initKey(passcode, context)
    }
    return dbCharKey ?: error("Failed to decrypt database key")
}

private fun initKey(passcode: CharArray, context: Context) {
    val storable = getStorable(context)
    if (storable == null) {
        createNewKey()
        persistRawKey(passcode)
    } else {
        rawByteKey = getRawByteKey(passcode, storable)
        dbCharKey = rawByteKey.toHex()
    }
}