SOCKS 5 Proxy with Go Lang

Original Library was imported from http://github.com/oov/socks5

I just modified and build for personal use.

this code support configuration loading.

• IP mask must be CIDR format like "1.2.3.0/24". If you want allow all client, use CIDR as "0.0.0.0/0"
• If ID/PW is supplied, use that. or IP restrictions

Additional Feature

• HTTPS(SNI) Censorship in korea avoid function.

  • you can check the code at "socks5/server.go"
  • Tested 2019-02-19 (SK Broadband, Korea)

• IPv6 Support

  • Some ISP only support IPv6 connection environment (Ex: Mobile phone tethering). and this proxy can support that.
  • tested OK. (2021-03-13 / SK telecomm, iPhone + Macbook Tethering, Korea)

• Can be run as Cascade/Upstream Proxy.

  • You can setup with Adguard or some program. and works well :)

Installation

• if you want to use with windows, use released binary.
• if you want to use with linux(x86_64), just execute these command in console.

  wget https://github.com/ziozzang/socks5-proxy/releases/download/1.0/socks5-proxy && chmod +x socks5-proxy
  wget https://github.com/ziozzang/socks5-proxy/releases/download/1.0/socks5-proxy.config.template 

or you can run with docker. :)

docker build -t socks5proxy .
docker run --rm -it -v `pwd`/socks5-proxy.config:/app/socks5-proxy.config --net=host socks5proxy

• don't forget to edit configuration.

Original socks5

Package socks5 implements a "SOCKS Protocol Version 5" server.

This server supports a subset of RFC 1928:

• auth methods: "NO AUTHENTICATION REQUIRED", "USERNAME/PASSWORD"
• commands: "CONNECT"
• address types: "IP V4 address", "DOMAINNAME", "IP V6 address" (but tested "DOMAINNAME" only)

INSTALL

go get -u github.com/oov/socks5

USAGE

package main

import (
    "github.com/oov/socks5"
    "log"
)

func main() {
    srv := socks5.New()
    srv.AuthUsernamePasswordCallback = func(c *socks5.Conn, username, password []byte) error {
        user := string(username)
        if user != "guest" {
            return socks5.ErrAuthenticationFailed
        }

        log.Printf("Welcome %v!", user)
        c.Data = user
        return nil
    }
    srv.HandleConnectFunc(func(c *socks5.Conn, host string) (newHost string, err error) {
        if host == "example.com:80" {
            return host, socks5.ErrConnectionNotAllowedByRuleset
        }
        if user, ok := c.Data.(string); ok {
            log.Printf("%v connecting to %v", user, host)
        }
        return host, nil
    })
    srv.HandleCloseFunc(func(c *socks5.Conn) {
        if user, ok := c.Data.(string); ok {
            log.Printf("Goodbye %v!", user)
        }
    })

    srv.ListenAndServe(":12345")
}