Ubuntu Notepad安全設置

Note: Ubuntu does not include a built-in application named “Notepad” (a default text editor in Windows). For text editing, Ubuntu uses tools like Nano, Vim, or Gedit. Below are Ubuntu system-wide security settings to protect your environment, which also apply to text editors and their associated files.

1. System Updates

Keep Ubuntu and all installed packages (including text editors) up to date to patch known vulnerabilities. Run the following commands regularly:

sudo apt update && sudo apt upgrade -y

For automatic updates, install unattended-upgrades:

sudo apt install unattended-upgrades
sudo dpkg-reconfigure unattended-upgrades

2. File Permissions Management

Restrict access to sensitive files (e.g., configuration files for text editors like ~/.config/nano/ or ~/.gconf/apps/gedit/) using chmod and chown:

• Set restrictive permissions: For personal files, use chmod 600 (owner: read/write; others: none). For shared directories, use chmod 755 (owner: full access; group/others: read/execute).

  chmod 600 ~/.config/nano/settings
  

• Verify ownership: Ensure files belong to your user account (not root unless necessary).

  chown $USER:$USER ~/.gconf/apps/gedit/preferences.ui
  

3. Use Strong Authentication & SSH Hardening

If accessing Ubuntu remotely via SSH (common for server environments), follow these steps:

• Disable root login: Edit /etc/ssh/sshd_config and set:

  PermitRootLogin no
  

• Use SSH key authentication: Generate a key pair on your local machine (ssh-keygen -t rsa -b 4096) and copy it to the server (ssh-copy-id user@server_ip). Disable password authentication in /etc/ssh/sshd_config:

  PasswordAuthentication no
  

• Change the default SSH port: Reduce brute-force attacks by modifying the port in /etc/ssh/sshd_config (e.g., Port 2222) and updating your firewall rules.

4. Configure a Firewall (UFW)

Use ufw (Uncomplicated Firewall) to allow only necessary traffic. For a basic setup:

sudo apt install ufw
sudo ufw allow ssh  # Allow SSH (port 22 or custom port)
sudo ufw allow http # Allow web traffic (if running a server)
sudo ufw enable     # Enable the firewall

Check status with sudo ufw status.

5. Encrypt Sensitive Data

Protect sensitive files (e.g., configuration files, logs) from unauthorized access:

• Encrypt home directory: During installation, choose the “Encrypt home directory” option. For existing users, use ecryptfs-migrate-home.
• Use VeraCrypt: Create encrypted containers for files/folders:

  sudo apt install veracrypt
  veracrypt -t -c ~/secure_container.tc  # Create a 1GB encrypted container
  

6. Enable Security Modules (SELinux/AppArmor)

Use Mandatory Access Control (MAC) to restrict application permissions:

• AppArmor (default in Ubuntu): Enable and configure profiles for text editors. For example, to restrict Nano’s access:

  sudo aa-enforce /etc/apparmor.d/usr.bin.nano
  

• SELinux (optional): Install and enable SELinux for stricter control:

  sudo apt install selinux
  sudo setenforce 1
  

7. Monitor System Activity

Detect suspicious behavior (e.g., unauthorized file access) using:

• Auditd: Install and configure to monitor file access:

  sudo apt install auditd
  sudo auditctl -w /home/$USER/.config/nano/ -p war -k nano_config  # Watch nano config directory
  

• Fail2Ban: Block malicious IPs after repeated failed login attempts:

  sudo apt install fail2ban
  sudo systemctl enable fail2ban
  

8. Regular Backups

Back up important files (e.g., text editor configurations, documents) to an external drive or cloud storage. Use rsync for incremental backups:

rsync -avz --delete /home/$USER/Documents/ /mnt/backup/Documents/

These measures will significantly enhance the security of your Ubuntu environment, including the text editors you use. Adjust configurations based on your specific needs (e.g., server vs. desktop).