[Android Auto] Investigate how we need to handle trusted hosts

@kmadsen commented on Thu May 27 2021

The car library has a HostValidator

Which essentially makes the 1tap app a trusted host with the head unit. You can find where this is in the MainCarAppService. I don't fully understand either, so this ticket is to figure it out and share your findings.

class MainCarAppService : CarAppService() {
    override fun createHostValidator(): HostValidator {
        return HostValidator.ALLOW_ALL_HOSTS_VALIDATOR
        // TODO limit hosts for production
        //    https://github.com/mapbox/1tap-android/issues/988
//        return HostValidator.Builder(this)
//                .addAllowedHosts(R.array.android_auto_allow_list)
//                .build()
    }

    override fun onCreateSession(): Session {
        return MainCarSession()
    }
}

从 MainCarAppService 和链接的 AndroidX HostValidator 文档开始，重点关注当前的 ALLOW_ALL_HOSTS_VALIDATOR 配置以及已注释的 allow-list 替代方案。记录生产环境中应如何处理受信任的主机，并在 issue 中分享调查结果和建议。