Debian 13

How to Setup an SFTP Server on Debian 13

To setup an SFTP server on Debian 13, follow the steps below.

Step 1 : Update the package list and upgrade existing packages.

sudo apt update && sudo apt upgrade -y

Step 2 : Install the OpenSSH server if it is not already installed.

sudo apt install -y openssh-server

Verify that the SSH service is running:

sudo systemctl status ssh

Step 3 : Edit sshd_config and Add SFTP Configuration

Open the SSH configuration file:

sudo nano /etc/ssh/sshd_config

Add the following SFTP configuration at the end of the file:

Subsystem sftp internal-sftp

Match Group sftpusers
        ChrootDirectory %h
        X11Forwarding no
        AllowTcpForwarding no
        ForceCommand internal-sftp

Save and exit the file.

Step 4 : Apply the configuration changes by restarting SSH.

sudo systemctl restart ssh

Step 5 : Create a dedicated group for SFTP users.

sudo groupadd sftpusers

Step 6 : Create a new SFTP user account.

sudo adduser sftpuser

Follow the prompts to set a password and user details.

Step 7 : Add the user to the SFTP group.

sudo usermod -aG sftpusers sftpuser

Step 8 : Set correct ownership and permissions for the SFTP user's home directory.

sudo chown root:root /home/sftpuser
sudo chmod 755 /home/sftpuser
sudo mkdir /home/sftpuser/upload
sudo chown sftpuser:sftpuser /home/sftpuser/upload
sudo chmod 755 /home/sftpuser/upload

This setup ensures the user can upload files only inside the upload directory.

Step 9 : If you want to allow password authentication, ensure the following settings exist in /etc/ssh/sshd_config:

PasswordAuthentication yes

Save the file after making changes.

Step 10 : Restart the SSH service again to apply all changes.

sudo systemctl restart ssh

Step 11 : Test the SFTP Connection

- Open an SFTP client such as FileZilla.

- Add a New Site : Go to File → Site Manager → New Site.

- Fill in the connection details step by step:

  • Protocol: SFTP – SSH File Transfer Protocol
  • Host: Your server IP or domain
  • Port: 22
  • Logon Type: Normal
  • Username: sftpuser
  • Password: Your SFTP user password

- Click Connect.

- If FileZilla shows an “Unknown host key” warning, select Always trust this host and click OK.

- If configured correctly, you should be logged in and restricted to the user's directory.

Congratulations! You have successfully set up an SFTP server on Debian 13.