Everything About SSH 🔒🗝️

6 min readJun 15, 2022

What is SSH & Why We Use ?

SSH or Secure Shell is a network communication protocol that enables two computers to communicate (ex: http or hypertext transfer protocol, which is the protocol used to transfer hypertext such as web pages) and share data.

SSH Port Number : 22

How to Install SSH in Windows

Step 1: Open PowerShell With Run as Administration

Step 2: Copy this Command and Paste it

# Install the OpenSSH Client

Add-WindowsCapability -Online -Name OpenSSH.Client~~~~0.0.1.0

Step 3 : Copy this Command and Paste it

# Install the OpenSSH Server

Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0

Step 4:

Step 5: Restart Your PC/Computer

Step 6: Open CMD

// Make sure you are in same directory

C:\Users\yourprofile>

Type these Commands

// If there is no .ssh folder create it by (mkdir .ssh)

cd .ssh

// Generating New SSH Keys for Windows

ssh-keygen -t ed25519 -C "youremail@gmail.com"

// Press Enter 3 Times

// Check the files in .ssh

dir

// You have 2 keys

id_ed25519 is your private key (Never Share it with Anyone)
id_ed25519.pub (You can Share if you want to give access to others)

For Sharing File Access Always Share .pub key file

type id_ed25519.pub

// Copy It And Save it Somewhere

We will be need that key while sharing the access

Step 7: Open PowerShell with Administration

# Start the sshd service

Start-Service sshd

# OPTIONAL but recommended:

Set-Service -Name sshd -StartupType ‘Automatic’

# Confirm the Firewall rule is configured. It should be created automatically by setup. Run the following to verify

if (!(Get-NetFirewallRule -Name “OpenSSH-Server-In-TCP” -ErrorAction SilentlyContinue | Select-Object Name, Enabled)) { Write-Output “Firewall Rule ‘OpenSSH-Server-In-TCP’ does not exist, creating it…” New-NetFirewallRule -Name ‘OpenSSH-Server-In-TCP’ -DisplayName ‘OpenSSH Server (sshd)’ -Enabled True -Direction Inbound -Protocol TCP -Action Allow -LocalPort 22 } else { Write-Output “Firewall rule ‘OpenSSH-Server-In-TCP’ has been created and exists.” }

How to Install SSH in Ubuntu/Linux

The procedure to install a ssh server in Ubuntu Linux is as follows:

Open the terminal application for Ubuntu desktop.
For remote Ubuntu server you can use Ubuntu Terminal
Type this Command

 sudo apt update && sudo apt upgrade

4. Type command:# sudo apt-get install openssh-server

5. Enable the ssh service by typing:# sudo systemctl enable ssh

6. Start the ssh service by typing:# sudo systemctl start ssh

7. Configure firewall and open port 22

You must configure the Ubuntu Linux firewall called ufw. Here is how open or allow port 22 when using ufw on Ubuntu:
$ sudo ufw allow ssh $ sudo ufw enable $ sudo ufw status

8. Type this command

ssh-keygen -t ed25519 -C "youremail@gmail.com"

9. Press enter 3 times untill you get this

10.Setting up Permission on SSH Folder and Keys

Type this command’s Line By Line

sudo chmod 700 .ssh
cd .ssh 
sudo chmod 644 id_ed25519.pub 
sudo chmod 600 id_ed25519

11. Setting Up SSH Access

Friend 1 (A)
Friend 2 (B)

If Friend 1 wants to Access Friend 2 System Files

Then Friend 1 Should Share his Public keys with Friend 2

How it Looks

Friend 1 Will Go to His .ssh folder
Friend 1 Wil Copy the public key (id_ed25519.pub)
Friend 1 will share the public key to Friend 2
Now Friend 2 Will Open his .ssh folder
create a file name authorized_keys

To Create a File in Linux

touch authorized_keys

6. To Open the file

nano authorized_keys

7. Paste the Friend 1 Public Key in authorized_keysfile

8. Ctrl + O To Save the File

9. Ctrl + X To Exit it

10. Make Sure Both Friend 1 and Friend 2 are in Connected to Same Wifi Network

11. Now Friend 1 wants to Access Friend 2 File System

12. Friend 2 Should share his private ip and username of it

13. Friend 1 Should Open his Terminal and Type

ssh friendusername@friendprivateip

example

ssh suhail@192.168.0.239

14. Friend 1 Will Get This Message From Terminal

15. Type Yes

How to Install SSH in Mobile Phone (Android)

Step 1: Install Termux App (Click Here)

Step 2: Type this Command

apt install openssh

Step 3: Type this Command

sudo apt update && sudo apt upgrade

Step 4: Type this command

ssh-keygen -t ed25519 -C "youremail@gmail.com"

Step 5: Press Enter 3 times until you get this

Step 6: Setting up Permission on SSH Folder and Keys