Zhejiang University Router Configuration Guide

sorcererxw•September 12, 2018

Just enrolled, I found that the campus network uses srun 3000 for authentication, which can be authenticated through a client or a web page. However, whether it's the client or the web page, there is a window that cannot be closed after logging in. Once it's closed, the network will be disconnected. Although it can be thrown to a newly created desktop, out of sight, out of mind, this is unbearable.

Fortunately, I brought my own router. My router is the ASUS P1900, which has been flashed with the original Merlin system. However, the following operations are also applicable to OpenWRT.

Failure: Using the Linux client¶

In the document at 196.0.0.6, the instructions for Linux login are to use the dedicated auth program srun 3000 for login.

However, after testing, it was found that this program cannot run on the router, and a Syntax error: "(" unexpected error will occur. After Googling, it was found that the compilation method of this client cannot run on the router.

Simulated Login¶

Since the client doesn't work, let's try simulated login. Log in on the web page, check with the Chrome console, and find that a request is sent to 192.0.0.6/cgi-bin/, with the login username and password stored in formdata (the password has been processed with md5).

In this way, you can also log in using the curl command, but handling exception information can be a bit troublesome.

One-click script¶

After a search, I found that there is already a campus network authentication script on github. Thanks to the author🙏.

Considering that the router is not connected to the network and cannot directly clone the project, I will post the code here. You can simply copy and paste it into ssh.

First, switch the router's external network (wan) to dynamic IP mode.

SSH into the router

# 可以放置在任意的目录, 我放在 /jffs, 请不要选择 /tmp 目录, 包括 /tmp 下的任意子目录, 可能会被定时清除
mkdir /jffs/srunauth && cd $_
vi auth.sh

Paste a section of code below, and make modifications according to the comments.

#!/bin/bash 
# 如果路由器没有 bash ( /bin/bash ) 就替换成 /bin/sh
# Author HJK <https://github.com/0xHJK>

USERNAME='' # 填上用户名 ( 学号 )
PASSWORD='' # 密码 ( 直接填, 不需要 md5 )
USERSFILE='users.txt'
STATEFILE='state.txt'
DOMAIN='192.0.0.6'
COMMOND='do_login'
VERBOSE='y'

usage(){
    echo "Usage: bash `basename $0` [-q] [-u username] [-p password] [-f file] [Commond]"
    echo "Commonds: login, logout"
    exit 1
}
md5_hash(){
    if [[ `uname | grep 'Darwin'` ]]; then
        echo -n ${1} | md5 -q | cut -c9-24
    else
        echo -n ${1} | md5sum | cut -c9-24
    fi
}

say_out(){
    if [[ ${VERBOSE} == 'y' ]]; then echo $*; fi
}

submit(){
    msg=`curl -s "http://${DOMAIN}/cgi-bin/${1}" -H 'Pragma: no-cache' -H "Origin: http://${DOMAIN}" -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.6,en;q=0.4' -H 'User-Agent: Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Win64; x64; Trident/6.0)' -H 'Content-Type: application/x-www-form-urlencoded' -H 'Accept: */*' -H 'Cache-Control: no-cache' -H "Referer: http://${DOMAIN}/" -H 'Connection: keep-alive' -H 'DNT: 1' --data "username=${2}&password=${3}&drop=0&type=1&n=1" --compressed`
    if [[ `echo ${msg} | grep 'ip_exist_error'` ]]; then
        echo "IP尚未下线  ${msg}"
    elif [[ `echo ${msg} | grep 'online_num_error'` ]]; then
        echo "账号 ${USERNAME} 登录人数超过限额 ${msg}"
    elif [[ `echo ${msg} | grep 'username_error'` ]]; then
        echo "用户名 ${USERNAME} 错误  ${msg}"
    elif [[ `echo ${msg} | grep 'password_error'` ]]; then
        echo "密码 ${PASSWORD} 错误  ${msg}"
    elif [[ `echo ${msg} | grep 'logout_ok'` ]]; then
        echo "账号 ${USERNAME} 注销成功  ${msg}"
    elif [[ `echo ${msg} | grep '[0-9]\{10,\}'` ]]; then
        echo "账号 ${USERNAME} 登录成功  ${msg}"
    else
        echo "未知消息 ${msg}"
    fi
}

# 当有参数时获取参数
if [ $# -gt 0 ]; then
    while getopts :qu:p:f: OPTION
    do
        case $OPTION in
            q) VERBOSE='n' ;;
            u) USERNAME=$OPTARG ;;
            p) PASSWORD=$OPTARG ;;
            f) USERSFILE=$OPTARG ;;
            \?) usage ;;
        esac
    done
fi

shift $(($OPTIND - 1)) # 如果这一句话出错, 注释掉

# 如果登录
if [ $# -eq 0 ] || [[ $1 == 'login' ]]; then
    # 如果账号密码为空，则从文件里读取
    if [[ ${USERNAME} == '' ]] || [[ ${PASSWORD} == '' ]]; then
        while read l1; do
            USERNAME=`echo -n $l1 | awk '{ print $1 }'`
            PASSWORD=`echo -n $l1 | awk '{ print $2 }'`
            say_out "正在尝试登录 ${USERNAME} ${PASSWORD}"
            PASSWORD=`md5_hash ${PASSWORD}`
            # 如果登录成功，则退出循环，并记录账号密码
            state=`submit 'do_login' ${USERNAME} ${PASSWORD}`
            say_out "state: ${state}"
            if [[ `echo "${state}" | grep '成功'` ]]; then
                echo "${USERNAME} 登录成功"
                echo "${USERNAME} ${PASSWORD}" > ${STATEFILE}
                exit
            fi
        done < ${USERSFILE}
        echo "所有账号登录失败"
    else
        say_out "正在尝试登录 ${USERNAME} ${PASSWORD}"
        PASSWORD=`md5_hash ${PASSWORD}`
        submit 'do_login' ${USERNAME} ${PASSWORD}
    fi
# 如果注销
elif [[ $1 == 'logout' ]]; then
    # 如果账号密码为空，则从文件里读取
    if [[ ${USERNAME} == '' ]] || [[ ${PASSWORD} == '' ]]; then
        USERNAME=`cat ${STATEFILE} | awk '{ print $1 }'`
        PASSWORD=`cat ${STATEFILE} | awk '{ print $2 }'`
        say_out "正在尝试注销 ${USERNAME} ${PASSWORD}"
    fi
    submit 'force_logout' ${USERNAME} ${PASSWORD}
else
    usage
fi

Finally, exit with :wq

chmod +x auth.sh
touch state.txt users.txt

Configuration completed.

Run ./auth.sh to log in, and ./auth.sh logout to log out.