sfcode An Online Competing and Development Environment

socks examples

# Example for SOCKS 'connect' command

The connect command is the most common use-case for a SOCKS proxy. This establishes a direct connection to a destination host through a proxy server. The destination host only has knowledge of the proxy server connecting to it and does not know about the origin client (you).

Origin Client (you) <-> Proxy Server <-> Destination Server

In this example, we are connecting to a web server on port 80, and sending a very basic HTTP request to receive a response. It's worth noting that there are many socks-http-agents that can be used with the node http module (and libraries such as request.js) to make this easier. This HTTP request is used as a simple example.

The 'connect' command can be used via the SocksClient.createConnection() factory function as well as by creating a SocksClient instance and using event handlers.

## Using createConnection with async/await

Since SocksClient.createConnection returns a Promise, we can easily use async/await for flow control.

import { SocksClient, SocksClientOptions } from 'socks';
const options: SocksClientOptions = {
proxy: {
host: '104.131.124.203',
port: 1081,
type: 5
},
destination: {
host: 'ip-api.com', // host names are supported with SOCKS v4a and SOCKS v5.
port: 80
},
command: 'connect'
};
async function start() {
try {
const info = await SocksClient.createConnection(options);
console.log(info.socket);
// <Socket ...> (this is a raw net.Socket that is established to the destination host through the given proxy servers)
info.socket.write('GET /json HTTP/1.1\nHost: ip-api.com\n\n');
info.socket.on('data', (data) => {
console.log(data.toString()); // ip-api.com sees that the last proxy (104.131.124.203) is connected to it and not the origin client (you).
/*
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
Date: Sun, 24 Dec 2017 03:47:51 GMT
Content-Length: 300
{
"as":"AS14061 Digital Ocean, Inc.",
"city":"Clifton",
"country":"United States",
"countryCode":"US",
"isp":"Digital Ocean",
"lat":40.8326,
"lon":-74.1307,
"org":"Digital Ocean",
"query":"104.131.124.203",
"region":"NJ",
"regionName":"New Jersey",
"status":"success",
"timezone":"America/New_York",
"zip":"07014"
}
*/
});
} catch (err) {
// Handle errors
}
}
start();

## Using createConnection with Promises

import { SocksClient, SocksClientOptions } from 'socks';
const options: SocksClientOptions = {
proxy: {
ipaddress: '104.131.124.203',
port: 1081,
type: 5
},
destination: {
host: 'ip-api.com', // host names are supported with SOCKS v4a and SOCKS v5.
port: 80
},
command: 'connect'
};
SocksClient.createConnection(options)
.then(info => {
console.log(info.socket);
// <Socket ...> (this is a raw net.Socket that is established to the destination host through the given proxy servers)
info.socket.write('GET /json HTTP/1.1\nHost: ip-api.com\n\n');
info.socket.on('data', (data) => {
console.log(data.toString()); // ip-api.com sees that the last proxy (104.131.124.203) is connected to it and not the origin client (you).
/*
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
Date: Sun, 24 Dec 2017 03:47:51 GMT
Content-Length: 300
{
"as":"AS14061 Digital Ocean, Inc.",
"city":"Clifton",
"country":"United States",
"countryCode":"US",
"isp":"Digital Ocean",
"lat":40.8326,
"lon":-74.1307,
"org":"Digital Ocean",
"query":"104.131.124.203",
"region":"NJ",
"regionName":"New Jersey",
"status":"success",
"timezone":"America/New_York",
"zip":"07014"
}
*/
});
})
.catch(err => {
// handle errors
});

## Using createConnection with callbacks

SocksClient.createConnection() optionally accepts a callback function as a second parameter.

Note: If a callback function is provided, a Promise is still returned from the function, but the promise will always resolve regardless of if there was en error. (tldr: Do not mix callbacks and Promises).

import { SocksClient, SocksClientOptions } from 'socks';
const options: SocksClientOptions = {
proxy: {
ipaddress: '104.131.124.203',
port: 1081,
type: 5
},
destination: {
host: 'ip-api.com', // host names are supported with SOCKS v4a and SOCKS v5.
port: 80
},
command: 'connect'
};
SocksClient.createConnection(options, (err, info) => {
if (err) {
// handle errors
} else {
console.log(info.socket);
// <Socket ...> (this is a raw net.Socket that is established to the destination host through the given proxy servers)
info.socket.write('GET /json HTTP/1.1\nHost: ip-api.com\n\n');
info.socket.on('data', (data) => {
console.log(data.toString()); // ip-api.com sees that the last proxy (104.131.124.203) is connected to it and not the origin client (you).
/*
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
Date: Sun, 24 Dec 2017 03:47:51 GMT
Content-Length: 300
{
"as":"AS14061 Digital Ocean, Inc.",
"city":"Clifton",
"country":"United States",
"countryCode":"US",
"isp":"Digital Ocean",
"lat":40.8326,
"lon":-74.1307,
"org":"Digital Ocean",
"query":"104.131.124.203",
"region":"NJ",
"regionName":"New Jersey",
"status":"success",
"timezone":"America/New_York",
"zip":"07014"
}
*/
});
}
})

## Using event handlers

SocksClient also supports instance creation of a SocksClient. This allows for event based flow control.

import { SocksClient, SocksClientOptions } from 'socks';
const options: SocksClientOptions = {
proxy: {
ipaddress: '104.131.124.203',
port: 1081,
type: 5
},
destination: {
host: 'ip-api.com', // host names are supported with SOCKS v4a and SOCKS v5.
port: 80
},
command: 'connect'
};
const client = new SocksClient(options);
client.on('established', (info) => {
console.log(info.socket);
// <Socket ...> (this is a raw net.Socket that is established to the destination host through the given proxy servers)
info.socket.write('GET /json HTTP/1.1\nHost: ip-api.com\n\n');
info.socket.on('data', (data) => {
console.log(data.toString()); // ip-api.com sees that the last proxy (104.131.124.203) is connected to it and not the origin client (you).
/*
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=utf-8
Date: Sun, 24 Dec 2017 03:47:51 GMT
Content-Length: 300
{
"as":"AS14061 Digital Ocean, Inc.",
"city":"Clifton",
"country":"United States",
"countryCode":"US",
"isp":"Digital Ocean",
"lat":40.8326,
"lon":-74.1307,
"org":"Digital Ocean",
"query":"104.131.124.203",
"region":"NJ",
"regionName":"New Jersey",
"status":"success",
"timezone":"America/New_York",
"zip":"07014"
}
*/
});
});
// Failed to establish proxy connection to destination.
client.on('error', () => {
// Handle errors
});
// Start connection
client.connect();