This tutorial explains how to install and configure an FTP server on Raspberry Pi that you use to share files between your devices. We’ll use vsftpd, which a stable, secure, and fast FTP server. We will also show you how to configure vsftpd to restrict users to their home directory and encrypt the entire transmission with SSL/TLS.

For this project, you should have Raspbian installed on your Raspberry Pi . Running an FTP server doesn’t require a graphical interface, so our recommendation is to use the Raspbian Lite image and enable SSH .

Installing vsftpd on Raspberry Pi #

The vsftpd package is available in the standard Raspbian repositories. To install it, run the following commands:

sudo apt updatesudo apt install vsftpd

The ftp service will automatically start after the installation process is complete. To verify it, print the service status:

sudo systemctl status vsftpd

The output will look something like below, showing that the vsftpd service is active and running:

● vsftpd.service - vsftpd FTP server
   Loaded: loaded (/lib/systemd/system/vsftpd.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2020-10-21 19:00:41 BST; 9s ago
...

Configuring vsftpd #

The vsftpd server sensors can be configured by editing the /etc/vsftpd.conf file.

Most of the settings are well documented inside the configuration file. For all available options, visit the official vsftpd page.

Start by opening the vsftpd configuration file:

sudo nano /etc/vsftpd.conf

1. FTP Access #

To ensure that only the local users can access the FTP server, search for the anonymous_enable and local_enable directives and verify your configuration match to lines below:

anonymous_enable=NO
local_enable=YES

2. Enabling uploads #

Locate and uncomment the write_enable directive to allow changes to the filesystem, such as uploading and removing files.

write_enable=YES

3. Chroot Jail #

To prevent the FTP users from accessing files outside of their home directories, uncomment the chroot directive.

chroot_local_user=YES

When the chroot feature is active, vsftpd will refuse to upload files if the directory that the users are locked in is writable.

Use one of the solutions below to make the chroot environment writable:

• Method 1. – The recommended option to allow upload is to keep chroot enabled and configure FTP directories. In this example, we will create an ftp directory inside the user home, which will serve as the chroot and a writable uploads directory for uploading files.

  /etc/vsftpd.conf

  user_sub_token=$USER
  local_root=/home/$USER/ftp

• Method 2. – Another option is to add the following directive in the vsftpd configuration file. Use this option if you must to grant writable access to your user to its home directory.

  /etc/vsftpd.conf

  allow_writeable_chroot=YES

4. Passive FTP Connections #

By default, vsftpd uses active mode. To use passive mode, set the minimum and maximum range of ports:

pasv_min_port=30000
pasv_max_port=31000

vsftpd can use any port for passive FTP connections. When the passive mode is enabled, the FTP client opens a connection to the server on a random port in the range you have chosen.

5. Limiting User Login #

You can configure vsftpd to permit only certain users to log in. To do so, add the following lines at the end of the file:

userlist_enable=YES
userlist_file=/etc/vsftpd.user_list
userlist_deny=NO

When this feature is enabled, you need to explicitly specify which users can log in by adding the user names to the /etc/vsftpd.user_list file (one user per line).

6. Securing Transmissions with SSL/TLS #

To encrypt the FTP transmissions with SSL/TLS, you’ll need to have an SSL certificate and configure the FTP server to use it.

You can use an existing SSL certificate signed by a trusted Certificate Authority or create a self-signed certificate.

If you have a domain or subdomain pointing to the FTP server’s IP address, you can easily generate a free Let’s Encrypt SSL certificate.

In this tutorial, we will generate a self-signed SSL certificate using the openssl command.

Run the following command to create a 2048-bit private key and self signed certificate valid for 10 years. Both the private key and the certificate will be saved in a same file:

sudo openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout /etc/ssl/private/vsftpd.pem -out /etc/ssl/private/vsftpd.pem

Once the files are created, open the configuration file:

sudo nano /etc/vsftpd.conf

Find the rsa_cert_file and rsa_private_key_file directives, change their values to the pam file path and set the ssl_enable directive to YES:

rsa_cert_file=/etc/ssl/private/vsftpd.pem
rsa_private_key_file=/etc/ssl/private/vsftpd.pem
ssl_enable=YES

If not specified otherwise, the FTP server will use only TLS to make secure connections.

Restart the vsftpd service #

Once you are done configuring the server, the vsftpd configuration file (excluding comments) should look something like this:

listen=NO
listen_ipv6=YES
anonymous_enable=NO
local_enable=YES
write_enable=YES
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
chroot_local_user=YES
allow_writeable_chroot=YES
pasv_min_port=30000
pasv_max_port=31000
userlist_enable=YES
userlist_file=/etc/vsftpd.user_list
userlist_deny=NO
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
rsa_cert_file=/etc/ssl/private/vsftpd.pem
rsa_private_key_file=/etc/ssl/private/vsftpd.pem
ssl_enable=YES

Save the file and restart the vsftpd service for changes to take effect:

sudo systemctl restart vsftpd

Opening the Firewall #

If you are running a UFW firewall , you’ll need to allow FTP traffic.

To open port 21 (FTP command port), port 20 (FTP data port), and 30000-31000 (Passive ports range), run the following commands:

sudo ufw allow 20:21/tcpsudo ufw allow 30000:31000/tcp

Reload the UFW rules by disabling and re-enabling UFW:

sudo ufw disablesudo ufw enable

Creating FTP User #

To test the FTP server, we will create a new user.

• If you already have a user that you want to grant FTP access, skip the 1st step.
• If you set allow_writeable_chroot=YES in your configuration file, skip the 3rd step.

1. Create a new user named newftpuser:

   sudo adduser newftpuser

   When prompted, set the user password.

2. Add the user to the allowed FTP users list:

   echo "newftpuser" | sudo tee -a /etc/vsftpd.user_list

3. Create the FTP directory tree and set the correct permissions :

   sudo mkdir -p /home/newftpuser/ftp/uploadsudo chmod 550 /home/newftpuser/ftpsudo chmod 750 /home/newftpuser/ftp/uploadsudo chown -R newftpuser: /home/newftpuser/ftp

   As discussed in the previous section, the user will be able to upload files to the ftp/upload directory.

At this point, your FTP server is fully functional, and you should be able to connect to your server using any FTP client such as FileZilla .

Disabling Shell Access #

By default, when creating a user, if not explicitly specified the user will have SSH access to the device. To disable shell access, create a new shell that will simply print a message telling the user that their account is limited to FTP access only.

Create the /bin/ftponly shell and make it executable:

echo -e '#!/bin/sh\necho "This account is limited to FTP access only."' | sudo tee -a  /bin/ftponlysudo chmod a+x /bin/ftponly

Append the new shell to the list of valid shells in the /etc/shells file:

echo "/bin/ftponly" | sudo tee -a /etc/shells

Change the user shell to /bin/ftponly:

sudo usermod newftpuser -s /bin/ftponly

Use the same command to change the shell of all users you want to give only FTP access.

Conclusion #

We’ve shown you how to install and configure a secure and fast FTP server on your Raspberry Pi system.

If you have any questions or feedback, feel free to leave a comment.