Run tor.so from android app "net::ERR_NAME_NOT_RESOLVED"

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I'm writing a capacitor app using API 29 Android simulator for testing.I'm using the plugin capacitor-tor from https://www.npmjs.com/package/@start9labs/capacitor-tor

I have modified the plugin in a way that it now executes tor from the jnilibs folder as it is required for Api level 29+ and it seems running correctly as the log shows:

D/eglCodecCommon: setVertexArrayObject: set vao to 0 (0) 7 8
I/ConnectionChangeReceiver: Switching to ONLINE mode
D/eglCodecCommon: setVertexArrayObject: set vao to 1 (1) 7 4
D/eglCodecCommon: setVertexArrayObject: set vao to 0 (0) 7 8
D/eglCodecCommon: setVertexArrayObject: set vao to 1 (1) 7 4
D/eglCodecCommon: setVertexArrayObject: set vao to 0 (0) 7 8
I/t*.p*.OnionProxyManager: Enabling network: true
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 10% (conn_done): Connected to a relay
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
D/eglCodecCommon: setVertexArrayObject: set vao to 1 (1) 7 4
D/eglCodecCommon: setVertexArrayObject: set vao to 0 (0) 7 8
D/eglCodecCommon: setVertexArrayObject: set vao to 1 (1) 7 4
D/eglCodecCommon: setVertexArrayObject: set vao to 0 (0) 7 8
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 14% (handshake): Handshaking with a relay
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 15% (handshake_done): Handshake with a relay done
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 75% (enough_dirinfo): Loaded enough directory info to build circuits
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
I/*oxyManagerEventHandler: OR connection: status: CONNECTED, orName: $8ACD73BD9BDD5E5AFC97169C5837C5E0F732A2CF~SkynetW
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 90% (ap_handshake_done): Handshake finished with a relay to build circuits
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 95% (circuit_create): Establishing a Tor circuit
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
I/*oxyManagerEventHandler: OR connection: status: CONNECTED, orName: $6429B0D703EB90A18528F9F8B843504AA27765C6~rinderwahnRelay37L
I/*oxyManagerEventHandler: message: severity: NOTICE, msg: Bootstrapped 100% (done): Done
V/Capacitor/TorPlugin: Notifying listeners for event torInitProgress
D/Capacitor/TorPlugin: No listeners found for event torInitProgress
D/TorPlugin: Finishing off tor. Started successfully: true

As a test after 30 seconds I try again to start tor and it is already running as expected:

V/Capacitor/Plugin: To native (Capacitor plugin): callbackId: 51286662, pluginId: TorPlugin, methodName: start
V/Capacitor: callback: 51286662, pluginId: TorPlugin, methodName: start, methodData: {"socksPort":9250,"controlPort":9251,"initTimeout":15000}
D/TorPlugin: Kicking off tor
I/t*.p*.OnionProxyManager: Tor is already running
I/ConnectionChangeReceiver: Switching to ONLINE mode
I/t*.p*.OnionProxyManager: Enabling network: true
D/TorPlugin: Finishing off tor. Started successfully: true
I/t*.p*.OnionProxyManager: Enabling network: true

So it really looks as if tor was running correctly. Despite everything I get still net::ERR_NAME_NOT_RESOLVED for my requests made by the browserified version of socket.io and socks-proxy-agent in the javascript part:

var agent = new SocksProxyAgent("socks://localhost:9250");
var socket =  await io.connect(onion_v3_address.onion:3000, { agent: agent });
socket.on('connect', async socket => {
            console.log("connected to server");
            // either with send()
            socket.send('hello');            
});

error in chrome debugger:

GET http://onion_v3_address.onion:3000/socket.io/?EIO=4&transport=polling&t=NpbeiTH net::ERR_NAME_NOT_RESOLVED

(of course the real address was replaced with onion_v3_address.onion:3000)

Plugin was started with this:

Capacitor.Plugins.TorPlugin.start({socksPort: 9250, controlPort: 9251, initTimeout: 15000});

What is wrong? Is tor not available over localhost? Do I need to use a different ip than localhost? Is android blocking my requests somehow? What else can cause this problem?

The tor server at onion_v3_address.onion:3000 is of course reachable and working as expected when testing from linux or windows.

---

EDIT:

if using no agent like :

socket = await io.connect('127.0.0.1:9250', {resource: '/onion_v3_address.onion:3000'});

I get in chrome debugger:

Failed to load resource: the server responded with a status of 501 (Tor is not an HTTP Proxy)
(index):1 Access to XMLHttpRequest at 'http://127.0.0.1:9250/socket.io/?EIO=4&transport=polling&t=NpcLcw9' from origin 'http://localhost' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

So it really seems that tor is running correctly and I just don't know how to request correctly from the webview to tor???! Again: The javascript code where using the agent works on electron (linux,macOS,win) a 100%. And it worked with cordova using orbot.But I don't want to use orbot.

Answer 1

To fix the net::ERR_NAME_NOT_RESOLVED error when trying to resolve Onion domains, the proxy needs to do DNS resolution over Tor instead of using the local DNS resolver.

To get DNS resolution over Tor, change:

var agent = new SocksProxyAgent("socks://localhost:9250");

to:

var agent = new SocksProxyAgent("socks5h://localhost:9250");

When the SocksProxyAgent is instantiated with socks:// , DNS resolution is performed by the local resolver. Using socks5h:// tells the proxy to also send the DNS requests through the proxy which is exactly what is needed here in order to resolve onion domains.

This also prevents DNS leaks where requests are sent over Tor but DNS requests are not.