GameSpy login flow

main.go

package main

import (
	"fmt"
	"net"
	"os"
	"time"

	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"

	"github.com/dogclan/dumbspy/pkg/gamespy"
)

const (
	network = "tcp4"

	timeout = time.Duration(5) * time.Second
)

func main() {
	log.Logger = log.Output(zerolog.ConsoleWriter{Out: os.Stdout})

	raddr, err := net.ResolveTCPAddr(network, net.JoinHostPort("gpcm.bf2hub.com", "29900"))
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to resolve address")
	}

	conn, err := net.DialTCP(raddr.Network(), nil, raddr)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to connect")
	}

	defer func(conn net.Conn) {
		err2 := conn.Close()
		if err2 != nil {
			log.Error().
				Err(err2).
				Msg("Failed to close connection")
		}
	}(conn)

	prompt, err := read(conn, timeout)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to read login challenge prompt")
	}

	nick := "your-nick"
	password := "your-password"

	challenge := gamespy.RandString(32)
	login := new(gamespy.Packet)
	login.Set("login", "")
	login.Set("challenge", challenge)
	login.Set("uniquenick", nick)
	login.Set("response", gamespy.GenerateProof(
		nick,
		gamespy.ComputeMD5(password),
		challenge,
		prompt.Get("challenge"),
	))
	login.Set("port", "-15095")
	login.Set("productid", "10493")
	login.Set("gamename", "battlefield2")
	login.Set("namespaceid", "12")
	login.Set("sdkrevision", "3")
	login.Set("id", "1")

	err = write(conn, login, timeout)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to write login request")
	}

	response, err := read(conn, timeout)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to read login response")
	}

	if _, ok := response.Lookup("sesskey"); !ok {
		log.Fatal().Msg("Failed to log in")
	}

	log.Info().Msg("Logged in successfully")

	lookup := new(gamespy.Packet)
	lookup.Set("getprofile", "")
	lookup.Set("sesskey", response.Get("sesskey"))
	lookup.Set("profileid", response.Get("profileid"))
	lookup.Set("id", "2")

	err = write(conn, lookup, timeout)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to write profile lookup request")
	}

	_, err = read(conn, timeout)
	if err != nil {
		log.Fatal().
			Err(err).
			Msg("Failed to read profile lookup response")
	}
}

func read(conn net.Conn, timeout time.Duration) (*gamespy.Packet, error) {
	if err := conn.SetReadDeadline(time.Now().Add(timeout)); err != nil {
		return nil, fmt.Errorf("failed to set read deadline: %w", err)
	}

	log.Debug().Msg("Reading packet")
	buffer := make([]byte, 512)
	n, err := conn.Read(buffer)
	if err != nil {
		return nil, fmt.Errorf("failed to read packet: %w", err)
	}

	log.Debug().Msg("Parsing packet")
	packet, err := gamespy.NewPacketFromBytes(buffer[:n])
	if err != nil {
		return nil, fmt.Errorf("failed to parse packet: %w", err)
	}

	log.Debug().
		Bytes("data", packet.Bytes()).
		Msg("Received packet")

	return packet, nil
}

func write(conn net.Conn, packet *gamespy.Packet, timeout time.Duration) error {
	if err := conn.SetWriteDeadline(time.Now().Add(timeout)); err != nil {
		return fmt.Errorf("failed to set write deadline: %w", err)
	}

	log.Debug().
		Bytes("data", packet.Bytes()).
		Msg("Sending packet")
	if _, err := conn.Write(packet.Bytes()); err != nil {
		return fmt.Errorf("failed to send packet: %w", err)
	}

	return nil
}