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To configure vsftpd for virtual users, I followed this link.

Though I succeeded in making the virtual users log into the system but it didn't work exactly the way mentioned in the document I followed.

The document mentions to run the vsftpd by executing the binary file as ./vsftpd But when I ran, it showed error as below:

ravbholua@ravi:/usr/sbin$ which vsftpd
/usr/sbin/vsftpd
ravbholua@ravi:/usr/sbin$ sudo ./vsftpd
500 OOPS: could not bind listening IPv4 socket
ravbholua@ravi:/usr/sbin$ 

Please see below the content of the document mentioned in the link(my issue is at step 5 below):(I have mentioned the content below for your ease so that you may not need to go to link)

This example shows how to set up vsftpd / PAM with "virtual users". A virtual user is a user login which does not exist as a real login on the system. Virtual users can therefore be more secure than real users, beacuse a compromised account can only use the FTP server.

Virtual users are often used to serve content that should be accessible to untrusted users, but not generally accessible to the public.

Step 1) Create the virtual users database. We are going to use pam_userdb to authenticate the virtual users. This needs a username / password file in "db" format - a common database format. To create a "db" format file, first create a plain text files with the usernames and password on alternating lines. See example file "logins.txt" - this specifies "tom" with password "foo" and "fred" with password "bar". Whilst logged in as root, create the actual database file like this:

db_load -T -t hash -f logins.txt /etc/vsftpd_login.db (Requires the Berkeley db program installed). NOTE: Many systems have multiple versions of "db" installed, so you may need to use e.g. db3_load for correct operation. This is known to affect some Debian systems. The core issue is that pam_userdb expects its login database to be a specific db version (often db3, whereas db4 may be installed on your system).

This will create /etc/vsftpd_login.db. Obviously, you may want to make sure the permissions are restricted:

chmod 600 /etc/vsftpd_login.db

For more information on maintaing your login database, look around for documentation on "Berkeley DB", e.g. http://www.sleepycat.com/docs/utility/index.html


Step 2) Create a PAM file which uses your new database.

See the example file vsftpd.pam. It contains two lines:

auth required /lib/security/pam_userdb.so db=/etc/vsftpd_login account required /lib/security/pam_userdb.so db=/etc/vsftpd_login

This tells PAM to authenticate users using our new database. Copy this PAM file to the PAM directory - typically /etc/pam.d/

cp vsftpd.pam /etc/pam.d/ftp

(Note - if you set pam_service_name to e.g. vsftpd instead, you'll need to copy to /etc/pam.d/vsftpd).


Step 3) Set up the location of the files for the virtual users.

useradd -d /home/ftpsite virtual ls -ld /home/ftpsite (which should give): drwx------    3 virtual  virtual      4096 Jul 30 00:39 /home/ftpsite

We have created a user called "virtual" with a home directory "/home/ftpsite". Let's add some content to this download area:

cp /etc/hosts /home/ftpsite chown virtual.virtual /home/ftpsite/hosts


Step 4) Create your vsftpd.conf config file.

See the example in this directory. Let's go through it line by line:

anonymous_enable=NO local_enable=YES

This disables anonymous FTP for security, and enables non-anonymous FTP (which is what virtual users use).

write_enable=NO anon_upload_enable=NO anon_mkdir_write_enable=NO anon_other_write_enable=NO

These ensure that for security purposes, no write commands are allowed.

chroot_local_user=YES

This makes sure that the virtual user is restricted to the virtual FTP area /home/ftpsite we set up above.

guest_enable=YES guest_username=virtual

The guest_enable is very important - it activates virtual users! And guest_username says that all virtual users are mapped to the real user "virtual" that we set up above. This will also determine where on the filesystem the virtual users end up - the home directory of the user "virtual", /home/ftpsite.

listen=YES listen_port=10021

This puts vsftpd in "standalone" mode - i.e. not running from an inetd. This means you just run the vsftpd executable and it will start up. This also makes vsftpd listen for FTP requests on the non-standard port of 10021 (FTP is usually 21).

pasv_min_port=30000 pasv_max_port=30999

These put a port range on passive FTP incoming requests - very useful if you are configuring a firewall.

Copy the example vsftpd.conf file to /etc:

cp vsftpd.conf /etc/


Step 5) Start up vsftpd.

Go to the directory with the vsftpd binary in it, and:

./vsftpd

If all is well, the command will sit there. If all is not well, you will likely see some error message.


Step 6) Test.

Launch another shell session (or background vsftpd with CTRL-Z and then "bg"). Here is an example of an FTP session:

ftp localhost 10021 Connected to localhost (127.0.0.1). 220 ready, dude (vsFTPd 1.1.0: beat me, break me) Name (localhost:chris): tom 331 Please specify the password. Password: 230 Login successful. Have fun. Remote system type is UNIX. Using binary mode to transfer files. ftp> pwd 257 "/" ftp> ls 227 Entering Passive Mode (127,0,0,1,117,135) 150 Here comes the directory listing. 226 Transfer done (but failed to open directory). ftp> size hosts 213 147 ftp>

Comments: The password we gave was "foo". Do not be alarmed by the "failed to open directory". That is because the directory /home/ftpsite is not world readable (we could change this behaviour if we wanted using anon_world_readable_only=NO but maybe we want it this way for security. We can see that we have access to the "hosts" file we copied into the virtual FTP area, via the size command.

Why it didn't run as above thought the document mentions this way to run.

So, I had to run vsftpd as:

ravbholua@ravi:/usr/sbin$ sudo service vsftpd restart

Now, it works and the virtual users created are able to log into the common directory that I had set.

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