Securing Raspberry Pi (SSH keys, firewall) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to generate an SSH key pair on Raspberry Pi.

Raspberry Pi

ssh-keygen -t [1] -b 2048 -f ~/.ssh/id_rsa

Drag options to blanks, or click blank then click option'

Aecdsa

Bdsa

Crsa

Ded25519

Attempts:

3 left

💡 Hint

Common Mistakes

Using unsupported or less common key types like dsa.

The rsa algorithm is commonly used for SSH key generation and is widely supported.

2fill in blank

medium

Complete the command to copy your SSH public key to the Raspberry Pi for passwordless login.

Raspberry Pi

ssh-copy-id [1]@raspberrypi.local

Drag options to blanks, or click blank then click option'

Api

Broot

Cadmin

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'root' or other usernames that may not exist.

The default user on Raspberry Pi OS is pi, so you copy the key to that user.

3fill in blank

hard

Fix the error in the command to enable the UFW firewall on Raspberry Pi.

Raspberry Pi

sudo ufw [1]

Drag options to blanks, or click blank then click option'

Aon

Bactivate

Cstart

Denable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'start' or 'activate' which are not valid UFW commands.

The correct command to enable UFW is sudo ufw enable.

4fill in blank

hard

Fill both blanks to allow SSH and deny all other incoming connections using UFW.

Raspberry Pi

sudo ufw [1] ssh
sudo ufw [2] incoming

Drag options to blanks, or click blank then click option'

Aallow

Bdeny

Cblock

Dreject

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'block' or 'reject' which behave differently than 'deny'.

First, allow SSH connections with allow. Then deny all other incoming connections with deny.

5fill in blank

hard

Fill all three blanks to disable password authentication and root login in SSH config.

Raspberry Pi

sudo sed -i 's/[1] yes/[2] no/' /etc/ssh/sshd_config
sudo sed -i 's/[3] yes/[2] no/' /etc/ssh/sshd_config
sudo systemctl restart sshd

Drag options to blanks, or click blank then click option'

APermitRootLogin

Bno

CPasswordAuthentication

Dyes

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the config options or using 'yes' instead of 'no'.

Replace PasswordAuthentication yes with no to disable password login, and PermitRootLogin yes with no to disable root login.