# Final
## vimrc (optional)
1. `vim ~/.vimrc`
``` vimrc
set encoding=utf-8
set nu
syntax on
set ai
set shiftwidth=4
set tabstop=4
set expandtab
set smartindent
set backspace=2
set ruler
set ic
set number
set mouse=a
set hlsearch
inoremap {<CR> {<CR>}<Esc>ko
inoremap " ""<Esc>i
inoremap ' ''<Esc>i
```
## general
1. update time
```shell
$ sudo ntpdate clock.stdtime.gov.tw
$ tzsetup
```
3. update hostname
```shell
$ sudo vim /etc/rc.conf
```
4. `adduser`
```
name: judge
passwd: m30owme0w
shell: bash
```
5. `$ pw usermod judge -G wheel`
6. `$ visudo`
``` conf
limaox ALL=(ALL:ALL) NOPASSWD: ALL
judge ALL=(ALL:ALL) NOPASSWD: ALL
```
7. ssh key
``` shell
$ mkdir ~/.ssh
$ cp authorized_keys .ssh/authorized_keys
```
8. ssh config
`$ vim /etc/ssh/sshd_config
`
``` conf
Port 2222
PermitRootLogin no
PasswordAuthentication no
ChallengeResponseAuthentication no
```
9. ssh restart
```shell
$ service sshd restart
```
:::warning
因為 ssh_key only, 所以你之後 ssh 會連不上去, 建議你把 ssh public key >> authorized_keys
:::
## shell scripts
``` sh
#!/bin/bash
# Loop to create 50 users
for i in {0..49}; do
# Generate the username and password
username="sa_$(printf '%02d' $i)"
password="sa_$(printf '%02d' $((49 - i)))"
# Determine the default shell based on the username
if ((i % 2 == 0)); then
shell="/bin/sh"
else
shell="/bin/tcsh"
fi
# Create the user with the specified details
pw useradd -n $username -s $shell -m
echo "$passed" | pw usermod $username -h 0
echo "User created: $username"
done
```
## ZFS
1. `$ zpool list sa_pool`
2. scrub 來修復檔案
```shell
$ zpool scrub sa_pool
```
3. 檢查狀態 `zpool status sa_pool`
4. da1 是爛掉的, 我選擇使用 detach
```shell
$ sudo zpool detach sa_pool /dev/da1
```
5. 找到 zfsflag
```shell
$ find /mnt/sa_pool/sa_final -type f -name "zfsflag.txt" -exec grep -q "douwant2buildasn0wman" {} \; -print
```
7.
```shell
$ mv zfsflag.txt /home/judge
```
## web_client
1. `sudo vim /etc/hosts` 並加入以下行數
``` conf
10.187.10.1 sa-judge.meow
```
2. change privillage acess
``` shell
$ sudo chmod 666 /etc/hosts
```
## web_server
1. nginx server
``` conf
#user nobody;
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
client_max_body_size 0;
#round robin
upstream backend {
server facebook.sa;
server google.sa;
}
server {
listen 80;
server_name limaox.ncku;
rewrite ^(.*) https://$host$1 permanent;
return 301 https://$host$request_uri;
}
server {
listen 443 ssl;
server_name limaox.ncku;
ssl_certificate /usr/home/limaox/full.crt;
ssl_certificate_key /usr/home/limaox/private.key;
location / {
proxy_pass http://backend;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}
}
}
```
2. 生 server.conf
``` conf
default_bits = 2048
prompt = no
default_md = sha256
distinguished_name = req_distinguished_name
req_extensions = req_ext
[req_distinguished_name]
C = TW
ST = TN
L = TAINAN
O = NCKU
CN = limaox.ncku
[req_ext]
subjectAltName = @alt_names
[alt_names]
DNS.1 = limaox.ncku
```
3. 生成 certificate
``` shell
$ openssl genrsa -out private.key 2048
$ chmod 644 private.key
$ openssl req -new -sha256 -key private.key -out ca.req -config server.conf
$ chmod 777 ca.req
$ openssl x509 -req -in ca.req -CA ca.crt -CAkey ca.key -CAcreateserial -out private.crt -days 1024 -sha256 -extensions req_ext -extfile server.conf
$ chmod 777 private.crt
$ cat private.crt ca.crt >> full.crt
```
4. ```$ sudo service nginx restart```
5. 驗證鎖頭 (refresh 可能沒用, 我關掉頁面重開才 ok)
* 
* 憑證階層
```
saroot
final
limaox
limaox.ncku
```
## nfs_server
1. 載入 nfs server 並抓 `getflag.sh` 出來
``` shell
$ mkdir /mnt/nfs
$ mount -t nfs nfs.sa:/flagplace /mnt/nfs
$ cp /mnt/nfs/getflag.sh /usr/home/limaox
```
2. 讓被抓出來的 `getflag.sh` 生成flag
3. 生成 /etc/exports 檔
```
/data/shared -alldirs -network 10.187.1.0/24 -maproot=root
/data/shared -alldirs -ro
```
4. 加東西到 /etc/rc.conf
```conf
nfs_server_enable="YES"
nfs_reserved_port_only="NO"
```
5. ```$ sudo service nfsd restart```
:::warning
我的 /mnt/nfs 會因為 busy 而無法 umount 並導致 service nfsd restart 會無法使用, 可以選擇 reboot 或 殺掉使用的 process
:::
## firewall
1. ```$ sudo vim /etc/pf.conf```
```conf
# Allow loopback and outgoing traffic
pass out all
set skip on lo0
block in
# eth0 是我的 interface, 請檢查你的 interface 名稱 by ipconfig or ifconfig
pass in on eth0 inet proto icmp all icmp-type echoreq
# Create whitelist for SSH and NFS services
# 10.187.112.170 是我的 ip 請改成自己的
pass in on eth0 inet proto tcp from {10.187.0.0/23, 10.187.112.0/20, 10.187.112.170} to any port 2222
# 使用 rpcinfo -p 看 nfs 的 port
pass in on eth0 inet proto tcp from 10.187.0.0/23 to any port {111, 961, 2049}
pass in on eth0 inet proto tcp from any to any port {80, 443}
# Create blacklist for Nginx services
block in on eth0 inet proto tcp from {10.187.10.5, 10.187.0.253} to any port {80, 443}
```
2. 執行防火牆
```shell
$ sudo service pf enable
$ sudo service pf start
```
:::success
恭喜完成 final lab~~
:::
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