Setting Ftp User to Allow Upload to All of Server
Introduction
FTP, brusque for File Transfer Protocol, is a network protocol that was once widely used for moving files between a client and server. Information technology has since been replaced by faster, more than secure, and more user-friendly ways of delivering files. Many casual Internet users expect to download directly from their web browser with https, and command-line users are more likely to use secure protocols such every bit the scp or sFTP.
FTP is still used to support legacy applications and workflows with very specific needs. If you lot accept a choice of what protocol to use, consider exploring the more modern options. When yous practise demand FTP, yet, vsftpd is an excellent choice. Optimized for security, performance, and stability, vsftpd offers potent protection against many security problems establish in other FTP servers and is the default for many Linux distributions.
In this tutorial, nosotros'll show you lot how to configure vsftpd to allow a user to upload files to his or her home directory using FTP with login credentials secured by SSL/TLS.
Prerequisites
To follow along with this tutorial you will need:
- An Ubuntu 16.04 server with a non-root user with
sudoprivileges: You can learn more about how to ready a user with these privileges in our Initial Server Setup with Ubuntu 16.04 guide.
Once you lot have an Ubuntu server in identify, you're set to begin.
Step 1 — Installing vsftpd
Nosotros'll starting time by updating our package list and installing the vsftpd daemon:
- sudo apt-get update
- sudo apt-become install vsftpd
When the installation is complete, we'll copy the configuration file so we can start with a blank configuration, saving the original as a fill-in.
- sudo cp /etc/vsftpd.conf /etc/vsftpd.conf.orig
With a backup of the configuration in place, nosotros're ready to configure the firewall.
Step 2 — Opening the Firewall
Nosotros'll check the firewall status to come across if it'southward enabled. If then, we'll ensure that FTP traffic is permitted so you won't run into firewall rules blocking you when information technology comes time to test.
- sudo ufw status
In this instance, only SSH is allowed through:
Output
Status: active To Action From -- ------ ---- OpenSSH Permit Anywhere OpenSSH (v6) Allow Anywhere (v6) Yous may have other rules in place or no firewall rules at all. Since only ssh traffic is permitted in this case, nosotros'll need to add rules for FTP traffic.
Nosotros'll need to open ports twenty and 21 for FTP, port 990 for later on when we enable TLS, and ports 40000-50000 for the range of passive ports nosotros programme to gear up in the configuration file:
- sudo ufw allow 20/tcp
- sudo ufw allow 21/tcp
- sudo ufw allow 990/tcp
- sudo ufw permit 40000:50000/tcp
- sudo ufw status
At present our firewall rules looks like:
Output
Status: active To Action From -- ------ ---- OpenSSH Let Anywhere 990/tcp Permit Anywhere twenty/tcp Allow Anywhere 21/tcp ALLOW Anywhere 40000:50000/tcp ALLOW Anywhere OpenSSH (v6) Permit Anywhere (v6) xx/tcp (v6) ALLOW Anywhere (v6) 21/tcp (v6) ALLOW Anywhere (v6) 990/tcp (v6) ALLOW Anywhere (v6) 40000:50000/tcp (v6) ALLOW Anywhere (v6) With vsftpd installed and the necessary ports open, we're ready to proceed to the next step.
Step 3 — Preparing the User Directory
For this tutorial, we're going to create a user, just you may already accept a user in demand of FTP access. We'll have care to preserve an existing user's admission to their information in the instructions that follow. Yet, we recommend you start with a new user until you've configured and tested your setup.
Starting time, we'll add together a examination user:
- sudo adduser sammy
Assign a password when prompted and feel free to press "ENTER" through the other prompts.
FTP is generally more than secure when users are restricted to a specific directory.vsftpd accomplishes this with chroot jails. When chroot is enabled for local users, they are restricted to their home directory by default. Withal, because of the manner vsftpd secures the directory, it must non exist writable by the user. This is fine for a new user who should just connect via FTP, but an existing user may demand to write to their abode folder if they also shell access.
In this instance, rather than removing write privileges from the habitation directory, we're volition create an ftp directory to serve as the chroot and a writable files directory to hold the actual files.
Create the ftp folder, set its ownership, and exist certain to remove write permissions with the post-obit commands:
- sudo mkdir /dwelling/sammy/ftp
- sudo chown nobody:nogroup /home/sammy/ftp
- sudo chmod a-w /domicile/sammy/ftp
Permit'southward verify the permissions:
- sudo ls -la /home/sammy/ftp
Output
total eight 4 dr-xr-xr-x two nobody nogroup 4096 Aug 24 21:29 . four drwxr-xr-x 3 sammy sammy 4096 Aug 24 21:29 .. Adjacent, nosotros'll create the directory where files can exist uploaded and assign ownership to the user:
- sudo mkdir /home/sammy/ftp/files
- sudo chown sammy:sammy /abode/sammy/ftp/files
A permissions cheque on the files directory should return the following:
- sudo ls -la /abode/sammy/ftp
Output
full 12 dr-xr-xr-x iii nobody nogroup 4096 Aug 26 14:01 . drwxr-xr-x iii sammy sammy 4096 Aug 26 13:59 .. drwxr-xr-x ii sammy sammy 4096 Aug 26 fourteen:01 files Finally, we'll add together a test.txt file to use when we test later on:
- repeat "vsftpd test file" | sudo tee /domicile/sammy/ftp/files/test.txt
Now that we've secured the ftp directory and allowed the user access to the files directory, we'll turn our attention to configuration.
Step 4 — Configuring FTP Access
We're planning to allow a single user with a local beat out business relationship to connect with FTP. The 2 key settings for this are already set in vsftpd.conf. Offset by opening the config file to verify that the settings in your configuration match those below:
- sudo nano /etc/vsftpd.conf
/etc/vsftpd.conf
. . . # Allow anonymous FTP? (Disabled by default). anonymous_enable=NO # # Uncomment this to let local users to log in. local_enable=YES . . . Side by side nosotros'll need to modify some values in the file. In order to let the user to upload files, we'll uncomment the write_enable setting and then that we take:
/etc/vsftpd.conf
. . . write_enable=Aye . . . We'll also uncomment the chroot to prevent the FTP-connected user from accessing any files or commands exterior the directory tree.
/etc/vsftpd.conf
. . . chroot_local_user=Yes . . . We'll add a user_sub_token in order to insert the username in our local_root directory path so our configuration will work for this user and whatever time to come users that might be added.
/etc/vsftpd.conf
user_sub_token=$USER local_root=/abode/$USER/ftp We'll limit the range of ports that tin can be used for passive FTP to make certain enough connections are available:
/etc/vsftpd.conf
pasv_min_port=40000 pasv_max_port=50000 Note: We pre-opened the ports that we gear up here for the passive port range. If you change the values, exist sure to update your firewall settings.
Since we're only planning to permit FTP access on a case-by-case basis, we'll set the configuration so that access is given to a user simply when they are explicitly added to a listing rather than by default:
/etc/vsftpd.conf
userlist_enable=YES userlist_file=/etc/vsftpd.userlist userlist_deny=NO userlist_deny toggles the logic. When it is set to "Yeah", users on the listing are denied FTP access. When information technology is set to "NO", merely users on the list are allowed access. When y'all're done making the change, save and get out the file.
Finally, nosotros'll create and add our user to the file. We'll utilize the -a flag to append to file:
- echo "sammy" | sudo tee -a /etc/vsftpd.userlist
Double-check that it was added every bit you expected:
cat /etc/vsftpd.userlist Output
sammy Restart the daemon to load the configuration changes:
- sudo systemctl restart vsftpd
Now nosotros're set up for testing.
Step 5 — Testing FTP Access
We've configured the server to allow but the user sammy to connect via FTP. Let's make certain that's the case.
Bearding users should fail to connect: We disabled anonymous admission. Here we'll test that past trying to connect anonymously. If we've done it properly, anonymous users should be denied permission:
- ftp -p 203.0.113.0
Output
Continued to 203.0.113.0. 220 (vsFTPd 3.0.3) Name (203.0.113.0:default): anonymous 530 Permission denied. ftp: Login failed. ftp> Close the connection:
- adieu
Users other than sammy should neglect to connect: Next, nosotros'll endeavor connecting as our sudo user. They, as well, should be denied access, and it should happen before they're allowed to enter their password.
- ftp -p 203.0.113.0
Output
Connected to 203.0.113.0. 220 (vsFTPd 3.0.three) Proper name (203.0.113.0:default): sudo_user 530 Permission denied. ftp: Login failed. ftp> Close the connection:
- bye
sammy should be able to connect, as well equally read and write files: Hither, we'll make sure that our designated user _can_connect:
- ftp -p 203.0.113.0
Output
Connected to 203.0.113.0. 220 (vsFTPd 3.0.three) Proper noun (203.0.113.0:default): sammy 331 Please specify the password. Password: your_user's_password 230 Login successful. Remote system blazon is UNIX. Using binary mode to transfer files. ftp> We'll change into the files directory, so apply the get command to transfer the test file nosotros created before to our local machine:
- cd files
- get test.txt
Output
227 Entering Passive Mode (203,0,113,0,169,12). 150 Opening BINARY style data connexion for exam.txt (16 bytes). 226 Transfer consummate. xvi bytes received in 0.0101 seconds (1588 bytes/s) ftp> We'll plow right back around and try to upload the file with a new name to examination write permissions:
- put exam.txt upload.txt
Output
227 Entering Passive Style (203,0,113,0,164,71). 150 Ok to send data. 226 Transfer complete. sixteen bytes sent in 0.000894 seconds (17897 bytes/s) Shut the connection:
- bye
Now that we've tested our configuration, nosotros'll take steps to further secure our server.
Step 6 — Securing Transactions
Since FTP does non encrypt any data in transit, including user credentials, we'll enable TTL/SSL to provide that encryption. The first step is to create the SSL certificates for use with vsftpd.
Nosotros'll use openssl to create a new certificate and employ the -days flag to make it valid for ane twelvemonth. In the aforementioned command, we'll add a individual 2048-chip RSA cardinal. And so past setting both the -keyout and -out flags to the same value, the private primal and the document will be located in the same file.
Nosotros'll practice this with the post-obit command:
- sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/vsftpd.pem -out /etc/ssl/private/vsftpd.pem
You'll exist prompted to provide address information for your certificate. Substitute your own information for the questions below:
Output
Generating a 2048 chip RSA individual key ............................................................................+++ ...........+++ writing new private key to '/etc/ssl/individual/vsftpd.pem' ----- Y'all are about to be asked to enter information that will be incorporated into your certificate request. What y'all are almost to enter is what is chosen a Distinguished Name or a DN. There are quite a few fields but y'all tin can go out some bare For some fields there volition be a default value, If you enter '.', the field volition be left blank. ----- Country Name (2 letter lawmaking) [AU]:US Land or Province Name (full name) [Some-Land]:NY Locality Proper name (eg, city) []:New York City Arrangement Proper noun (eg, company) [Internet Widgits Pty Ltd]:DigitalOcean Organizational Unit Name (eg, section) []: Common Proper noun (e.thou. server FQDN or YOUR name) []: your_IP_address Email Address []: For more detailed information about the certificate flags, meet OpenSSL Essentials: Working with SSL Certificates, Private Keys and CSRs
Once yous've created the certificates, open up the vsftpd configuration file over again:
- sudo nano /etc/vsftpd.conf
Toward the bottom of the file, you should two lines that begin with rsa_. Comment them out so they look like:
/etc/vsftpd.conf
# rsa_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem # rsa_private_key_file=/etc/ssl/private/ssl-cert-snakeoil.key Beneath them, add the following lines which point to the certificate and private key we just created:
/etc/vsftpd.conf
rsa_cert_file=/etc/ssl/private/vsftpd.pem rsa_private_key_file=/etc/ssl/private/vsftpd.pem After that, nosotros will forcefulness the utilize of SSL, which will prevent clients that can't deal with TLS from connecting. This is necessary in order to ensure all traffic is encrypted but may force your FTP user to change clients. Change ssl_enable to Aye:
/etc/vsftpd.conf
ssl_enable=Yes Afterwards that, add together the following lines to explicitly deny anonymous connections over SSL and to require SSL for both information transfer and logins:
/etc/vsftpd.conf
allow_anon_ssl=NO force_local_data_ssl=YES force_local_logins_ssl=YES After this we'll configure the server to use TLS, the preferred successor to SSL past adding the post-obit lines:
/etc/vsftpd.conf
ssl_tlsv1=Yes ssl_sslv2=NO ssl_sslv3=NO Finally, nosotros will add ii more options. First, we will not require SSL reuse because it can break many FTP clients. Nosotros will crave "high" encryption nada suites, which currently ways key lengths equal to or greater than 128 bits:
/etc/vsftpd.conf
require_ssl_reuse=NO ssl_ciphers=HIGH When you're done, save and close the file.
Now, we need to restart the server for the changes to take effect:
- sudo systemctl restart vsftpd
At this point, we will no longer be able to connect with an insecure command-line client. If we tried, nosotros'd see something like:
- ftp -p 203.0.113.0
- Connected to 203.0.113.0.
- 220 (vsFTPd iii.0.three)
- Proper name ( 203.0.113.0:default): sammy
- 530 Non-anonymous sessions must use encryption.
- ftp: Login failed.
- 421 Service not bachelor, remote server has closed connection
- ftp>
Adjacent, we'll verify that nosotros tin connect using a client that supports TLS.
Footstep vii — Testing TLS with FileZilla
Most modern FTP clients tin can be configured to use TLS encryption. Nosotros will demonstrate how to connect using FileZilla considering of its cross platform support. Consult the documentation for other clients.
When yous first open FileZilla, notice the Site Manager icon just beneath the word File, the left-most icon on the height row. Click it:
A new window will open. Click the "New Site" button in the lesser correct corner:
Under "My Sites" a new icon with the words "New site" will appear. You lot tin can name it now or return later and utilize the Rename button.
You lot must fill out the "Host" field with the name or IP address. Under the "Encryption" drop downwardly menu, select "Require explicit FTP over TLS".
For "Logon Type", select "Ask for password". Fill up in the FTP user you lot created in the "User" field:
Click "Connect" at the lesser of the interface. You will be asked for the user's password:
Click "OK" to connect. Y'all should at present be connected with your server with TLS/SSL encryption.
When you've accustomed the document, double-click the files folder and drag upload.txt to the left to ostend that you're able to download files.
When you've done that, right-click on the local copy, rename it to upload-tls.txt` and drag information technology dorsum to the server to confirm that y'all can upload files.
You've now confirmed that you can securely and successfully transfer files with SSL/TLS enabled.
Step 8 — Disabling Shell Access (Optional)
If you're unable to utilise TLS because of client requirements, you can gain some security past disabling the FTP user's ability to log in whatever other way. One relatively straightforward way to prevent information technology is by creating a custom beat. This volition not provide any encryption, but it volition limit the access of a compromised account to files accessible by FTP.
First, open up a file chosen ftponly in the bin directory:
- sudo nano /bin/ftponly
We'll add together a message telling the user why they are unable to log in. Paste in the post-obit:
#!/bin/sh echo "This account is limited to FTP access but." Change the permissions to brand the file executable:
- sudo chmod a+x /bin/ftponly
Open up the list of valid shells:
- sudo nano /etc/shells
At the lesser, add:
/etc/shells
. . . /bin/ftponly Update the user's shell with the following command:
- sudo usermod sammy -southward /bin/ftponly
Now endeavour logging in every bit sammy:
- ssh sammy@203.0.113.0
Y'all should see something like:
Output
This account is limited to FTP access only. Connection to 203.0.113.0 closed. This confirms that the user can no longer ssh to the server and is limited to FTP admission only.
Conclusion
In this tutorial we covered setting up FTP for users with a local business relationship. If you need to apply an external authentication source, you might want to wait into vsftpd's back up of virtual users. This offers a rich ready of options through the use of PAM, the Pluggable Authentication Modules, and is a good option if yous manage users in another organisation such as LDAP or Kerberos.
Source: https://www.digitalocean.com/community/tutorials/how-to-set-up-vsftpd-for-a-user-s-directory-on-ubuntu-16-04
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