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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 update
sudo 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 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:
/etc/vsftpd.conf
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.
/etc/vsftpd.conf
3. Chroot Jail #
To prevent the FTP users from accessing files outside of their home directories, uncomment the chroot
directive.
/etc/vsftpd.conf
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 writableuploads
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:
/etc/vsftpd.conf
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:
/etc/vsftpd.conf
userlist_enable=YES
userlist_file=/etc/vsftpd.user_list
userlist_deny=NO
/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
:
/etc/vsftpd.conf
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:
/etc/vsftpd.conf
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/tcp
sudo ufw allow 30000:31000/tcp
Reload the UFW rules by disabling and re-enabling UFW:
sudo ufw disable
sudo 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.
-
Create a new user named
newftpuser
:sudo adduser newftpuser
When prompted, set the user password.
-
Add the user to the allowed FTP users list:
echo "newftpuser" | sudo tee -a /etc/vsftpd.user_list
-
Create the FTP directory tree and set the correct permissions
:sudo mkdir -p /home/newftpuser/ftp/upload
sudo chmod 550 /home/newftpuser/ftp
sudo chmod 750 /home/newftpuser/ftp/upload
sudo 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/shnecho "This account is limited to FTP access only."' | sudo tee -a /bin/ftponly
sudo 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.
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