Snowflake in Orbot

Nameless · December 23, 2021, 11:43pm

Has snowflake reached orbot yet? I’ve got a 65mbps connection to loan if so

ukmr · December 24, 2021, 12:25pm

Orbot 16.5.2-RC-4 tor.0.4.6.9 was released 20 hours ago including a Snowflake update

arma · December 26, 2021, 7:23am

Wait, these are two different questions. Or at least, I think @ukmr is answering a different question than @Nameless asked.

Nameless is wanting to volunteer as a Snowflake, i.e. be one of the people who bridges traffic for censored users into the Tor network.

The update in Orbot is for the Snowflake client, i.e. the thing that censored users can use to reach the Tor network.

I know that the Guardian Project folks have been working on an app that can let you volunteer your phone as a Snowflake, and it tries to do it in a friendly way e.g. only offering it when you’re plugged in at night. We had a GSoC intern working on an app like that too. I don’t know what the current status is though. Maybe somebody here does?

ukmr · December 26, 2021, 11:47am

@arma Thanks for clarifying this. I was unaware of the app development by the Guardian Project, as you’ve described. This link provides an overview of the current status,

github.com/guardianproject/orbot

Snowflake Proxy Limiting is Misleading/Doesn't Work

opened 04:20AM - 10 Dec 21 UTC

bitmold

snowflake

By default there is a setting for using your device as a snowflake that's enable…d called "Snowflake Proxy Limits". It reads "Only when device is plugged in and on wifi". In `OrbotService`: ```java public static boolean isChargingAndWifi(Context context) { Intent intent = context.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1); boolean isCharging = plugged == BatteryManager.BATTERY_PLUGGED_AC || plugged == BatteryManager.BATTERY_PLUGGED_USB || plugged == BatteryManager.BATTERY_PLUGGED_WIRELESS; ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); boolean isUnmetered = cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isConnected() && (!cm.isActiveNetworkMetered()); return isCharging && isUnmetered; } ``` There are several things wrong with this appraoch: - Firstly `isChargingAndWifi(Context)` is called just when tor starts. If you lose power or lose wifi over night Orbot will continue to be a Snowflake proxy. While you're less likely to suddenly lose power, people with limited data plans could get hurt here if their wifi goes out... `OrbotService` needs to listen for events and turn off Snowflake if the user has this set - This method doesn't actually check if the device is on WiFi. **Limited cellular data plans can appear as unmetered. Users can be hurt here since they would assume Snowflake would not be running.** - WiFi networks *can* be metered so there are scenarios where the user is on WiFi and plugged in but Snowflake won't start. There are probably other scenarios where Android treats a WiFi network as "metered", but one is that [Access Points can apparently *hint* to their clients that their connection is metered](https://stackoverflow.com/questions/23877476/android-why-connectivitymanager-isactivenetworkmetered-always-returning-true). Basically if the "Vendor Info" of a DHCP lease (code 43) contains the text `"ANDROID_METERED"` the system will treat the wifi connection as metered. Android does this with mobile hotspots. What probably needs to happen: - The limiting feature should check to see if the device is plugged in, if the device is actually on wifi, and ensure that the wifi connection is unmetered - If any of these things go away Snowflake should definitely stop. - If these things return should snowflake start back up???