TUNET connector

tunet.go

package main

import (
	"bufio"
	"crypto/md5"
	"crypto/rc4"
	"encoding/base64"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
	"os/user"

	"github.com/gcmurphy/getpass"
)

var auth_file string
var toLogout bool

const (
	BASE_URL   = "https://net.tsinghua.edu.cn"
	LOGIN_URL  = BASE_URL + "/do_login.php"
	LOGOUT_URL = BASE_URL + "/do_login.php"
	KEY        = "tunet3.1415926"
)

func login(username, password string) error {
	h := md5.New()
	io.WriteString(h, password)
	md5pass := fmt.Sprintf("{MD5_HEX}%x", h.Sum(nil))

	form := url.Values{
		"username": {username},
		"password": {md5pass},
		"ac_id":    {"1"},
		"action":   {"login"},
	}

	resp, err := http.PostForm(LOGIN_URL, form)
	if err != nil {
		return err
	}

	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	fmt.Println(string(body))

	if err != nil {
		return err
	}
	return nil
}

func logout() error {
	form := url.Values{
		"action": {"logout"},
	}
	resp, err := http.PostForm(LOGIN_URL, form)
	if err != nil {
		return err
	}

	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	fmt.Println(string(body))

	if err != nil {
		return err
	}
	return nil
}

func encrypt(passwd string) string {
	c, _ := rc4.NewCipher([]byte(KEY))
	src := []byte(passwd)
	dst := make([]byte, len(passwd))
	c.XORKeyStream(dst, src)
	return base64.StdEncoding.EncodeToString(dst)
}

func decrypt(epasswd string) string {
	c, _ := rc4.NewCipher([]byte(KEY))
	src, _ := base64.StdEncoding.DecodeString(epasswd)
	dst := make([]byte, len(src))
	c.XORKeyStream(dst, src)
	return string(dst)
}

func main() {
	checkError := func(err error) {
		if err != nil {
			fmt.Printf("Error: %s\n", err.Error())
			os.Exit(1)
		}

	}

	usr, _ := user.Current()

	flag.StringVar(&auth_file, "a", usr.HomeDir+"/.tunet.passwd", "Username and password file")
	flag.BoolVar(&toLogout, "k", false, "Logout")
	flag.Parse()

	if toLogout {
		logout()
	} else {
		f, err := os.Open(auth_file)
		if os.IsNotExist(err) {
			fmt.Println("Auth file does not exist, initalizing")
			var username, passwd string
			fmt.Print("Username: ")
			fmt.Scanf("%s\n", &username)
			passwd, err := getpass.GetPassConfirm()
			checkError(err)

			f2, err := os.Create(auth_file)
			if err != nil {
				fmt.Printf("Error: %s\n", err.Error())

				fmt.Println("Plase paste following to ", auth_file)
				fmt.Println("----------------------------------------")
				fmt.Println(username)
				fmt.Println(encrypt(passwd))
				fmt.Println("----------------------------------------")
				os.Exit(1)
			} else {
				defer f2.Close()
				_, err = f2.WriteString(username + "\n")
				checkError(err)
				_, err = f2.WriteString(encrypt(passwd) + "\n")
				checkError(err)
				f2.Sync()
				login(username, passwd)
				return
			}
		} else {
			checkError(err)
		}

		defer f.Close()

		rd := bufio.NewReader(f)
		username, _, err := rd.ReadLine()
		checkError(err)
		epasswd, _, err := rd.ReadLine()
		checkError(err)
		passwd := decrypt(string(epasswd))
		login(string(username), string(passwd))
	}

}

tunet.sh

#!/bin/bash
USER="username"
PASSWORD="password"
PASSWORD=`echo -n $PASSWORD|md5sum|cut -d' ' -f1`

curl 'https://net.tsinghua.edu.cn/do_login.php' -X 'POST' -H 'Origin: http://net.tsinghua.edu.cn' \
	--data "action=login&username=${USER}&password={MD5_HEX}${PASSWORD}&ac_id=1"