Author Archives: cviorel - Page 12

HOWTO: Create a FTP server with user access (proftpd)

Posted by cviorel on September 19, 2007 1 comment | This post has 3,094 views.

A. The GUI way (for beginners only)

For those who are new to linux and don’t want to use a FTP server without GUI, or just for those who don’t use often their FTP server and wish to set it
quickly without a high level of security, there is a GTK GUI for proftpd.
Be careful, it’s less secure than configuring yourself your server.

1. Install proftpd and gproftpd with synaptic or with this command:
Code:

sudo apt-get install proftpd gproftpd

1	sudo apt-get install proftpd gproftpd

2. Play with the GUI and set up quickly your server.

Feel free to post here if you have some problems with gproftpd but it shouldn’t be too hard to use (it took me 2 minutes to set up a small FTP server ).

B. The secure way

1. Install proftpd with synaptic or with this command:
Code:

sudo apt-get install proftpd

1	sudo apt-get install proftpd

2. Add this line in /etc/shells file (sudo gedit /etc/shells to open the file):
Code:

/bin/false

1	/bin/false

Create a /home/ftp directory:
Code:

cd /home
sudo mkdir ftp

1 2	cd /home sudo mkdir ftp

Create a user named ftp_user which will be used only for ftp access. This user don’t need a valid shell (more secure) therefore select /bin/false shell
for ftp_user and /home/ftp as home directory (property button in user and group window).
To make this section clearer, i give you the equivalent command line to create the user, but it would be better to use the GUI (System -> Administration -> User -> Group) to create the user since users here often got problems with the user creation and the password (530 error) with the command line, so i really advice to use the GUI :
Code:

sudo useradd ftp_user -p your_password -d /home/ftp -s /bin/false
sudo passwd ftp_user

1 2	sudo useradd ftp_user -p your_password -d /home/ftp -s /bin/false sudo passwd ftp_user

In ftp directory create a download and an upload directory:
Code:

cd /home/ftp/
sudo mkdir download
sudo mkdir upload

cd /home/ftp/

sudo mkdir download

sudo mkdir upload

Now we have to set the good permissions for these directories:
Code:

cd /home
sudo chmod 755 ftp
cd ftp
sudo chmod 755 download
sudo chmod 777 upload

cd /home

sudo chmod 755 ftp

cd ftp

sudo chmod 755 download

sudo chmod 777 upload

3. OK, now go to the proftpd configuration file:
Code:

sudo gedit /etc/proftpd/proftpd.conf

1	sudo gedit /etc/proftpd/proftpd.conf

and edit your proftpd.conf file like that if it fit to your need:

Code:

# To really apply changes reload proftpd after modifications.
AllowOverwrite on
AuthAliasOnly on

# Choose here the user alias you want !!!!
UserAlias sauron userftp

ServerName "Server_Name"
ServerType standalone
DeferWelcome on

MultilineRFC2228 on
DefaultServer on
ShowSymlinks off

TimeoutNoTransfer 600
TimeoutStalled 100
TimeoutIdle 2200

DisplayFirstChdir .message
ListOptions "-l"

RequireValidShell off

TimeoutLogin 20

RootLogin off

# It's better for debug to create log files
ExtendedLog /var/log/ftp.log
TransferLog /var/log/xferlog
SystemLog /var/log/syslog.log

#DenyFilter \*.*/

# I don't choose to use /etc/ftpusers file (set inside the users you want to ban, not useful for me)
UseFtpUsers off

# Allow to restart a download
AllowStoreRestart on

# Port 21 is the standard FTP port, so you may prefer to use another port for security reasons (choose here the port you want)
Port 1980

# To prevent DoS attacks, set the maximum number of child processes
# to 30. If you need to allow more than 30 concurrent connections
# at once, simply increase this value. Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances 8

# Set the user and group that the server normally runs at.
User nobody
Group nogroup

# Umask 022 is a good standard umask to prevent new files and dirs
# (second parm) from being group and world writable.
Umask 022 022

PersistentPasswd off

MaxClients 8
MaxClientsPerHost 8
MaxClientsPerUser 8
MaxHostsPerUser 8

# Display a message after a successful login
AccessGrantMsg "welcome !!!"
# This message is displayed for each access good or not
ServerIdent on "you're at home"

# Set /home/ftp directory as home directory
DefaultRoot /home/ftp

# Lock all the users in home directory, ***** really important *****
DefaultRoot ~

MaxLoginAttempts 5

#VALID LOGINS

AllowUser userftp
DenyALL
</Limit>

<Directory /home/ftp>
Umask 022 022
AllowOverwrite off
<Limit MKD STOR DELE XMKD RNRF RNTO RMD XRMD>
DenyAll
</Limit>
</Directory>

<Directory /home/ftp/download/*>

Umask 022 022
AllowOverwrite off
<Limit MKD STOR DELE XMKD RNEF RNTO RMD XRMD>
DenyAll
</Limit>
</Directory>

<Directory> /home/ftp/upload/>
Umask 022 022
AllowOverwrite on
<Limit READ RMD DELE>

DenyAll
</Limit>

<Limit STOR CWD MKD>
AllowAll
</Limit>
</Directory>

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

# To really apply changes reload proftpd after modifications.

AllowOverwrite on

AuthAliasOnly on

# Choose here the user alias you want !!!!

UserAlias sauron userftp

ServerName "Server_Name"

ServerType standalone

DeferWelcome on

MultilineRFC2228 on

DefaultServer on

ShowSymlinks off

TimeoutNoTransfer 600

TimeoutStalled 100

TimeoutIdle 2200

DisplayFirstChdir .message

ListOptions "-l"

RequireValidShell off

TimeoutLogin 20

RootLogin off

# It's better for debug to create log files

ExtendedLog /var/log/ftp.log

TransferLog /var/log/xferlog

SystemLog /var/log/syslog.log

#DenyFilter \*.*/

# I don't choose to use /etc/ftpusers file (set inside the users you want to ban, not useful for me)

UseFtpUsers off

# Allow to restart a download

AllowStoreRestart on

# Port 21 is the standard FTP port, so you may prefer to use another port for security reasons (choose here the port you want)

Port 1980

# To prevent DoS attacks, set the maximum number of child processes

# to 30. If you need to allow more than 30 concurrent connections

# at once, simply increase this value. Note that this ONLY works

# in standalone mode, in inetd mode you should use an inetd server

# that allows you to limit maximum number of processes per service

# (such as xinetd)

MaxInstances 8

# Set the user and group that the server normally runs at.

User nobody

Group nogroup

# Umask 022 is a good standard umask to prevent new files and dirs

# (second parm) from being group and world writable.

Umask 022 022

PersistentPasswd off

MaxClients 8

MaxClientsPerHost 8

MaxClientsPerUser 8

MaxHostsPerUser 8

# Display a message after a successful login

AccessGrantMsg "welcome !!!"

# This message is displayed for each access good or not

ServerIdent on "you're at home"

# Set /home/ftp directory as home directory

DefaultRoot /home/ftp

# Lock all the users in home directory, ***** really important *****

DefaultRoot ~

MaxLoginAttempts 5

#VALID LOGINS

AllowUser userftp

DenyALL

</Limit>

Umask 022 022

AllowOverwrite off

DenyAll

</Limit>

</Directory>

Umask 022 022

AllowOverwrite off

DenyAll

</Limit>

</Directory>

<Directory> /home/ftp/upload/>

Umask 022 022

AllowOverwrite on

DenyAll

</Limit>

AllowAll

</Limit>

</Directory>

Ok you have done proftpd configuration. Your server is on port 1980 (in this exemple) and the access parameters are
user: ftp_user
password: the one you’ve set for ftp_user

4. To start/stop/restart your server:
Code:

sudo /etc/init.d/proftpd start
sudo /etc/init.d/proftpd stop
sudo /etc/init.d/proftpd restart

sudo /etc/init.d/proftpd start

sudo /etc/init.d/proftpd stop

sudo /etc/init.d/proftpd restart

To perform a syntax check of your proftpd.conf file:
Code:

sudo proftpd -td5

1	sudo proftpd -td5

To know who is connected on your server in realtime use “ftptop” command (use “t” caracter to swich to rate display), you can also use the “ftpwho”
command.

Prevent X.Org from Starting in Ubuntu

Posted by cviorel on September 19, 2007 No comments | This post has 513 views.

Prevent X.Org from Starting in Ubuntu

If you’ve got an Ubuntu machine that you initially installed with Ubuntu Desktop, but would like to run as a server, you can just disable the graphical
environment from starting up in order to save resources. This is also useful for doing system maintenance from the command line that needs to be performed
outside of the GUI.

The only reason to do this instead of removing the packages would be because you might want to still sometimes use the box through the GUI.

Disable X.Org

In order to disable the graphical environment, we’ll need to disable GDM, the Gnome Display Manager. In order to do this, you’ll need to run the following
command at the terminal:

sudo update-rc.d -f gdm remove

When you restart your computer, you’ll be presented with a text-mode login prompt instead of the graphical environment.

Run X.Org While Disabled

If you want to run the graphical environment, all you have to do is type the following command from the prompt, making sure to run it as your normal user
account.

startx

The annoying gray screen will go away once Gnome is fully started.

Enable X.Org

If you want to re-enable X11 it’s a simple matter of running this command from the terminal:

sudo update-rc.d -f gdm defaults

When you restart, you’ll be presented with the graphical prompt again.

Enable cupsys Web Admin Interface

Posted by cviorel on July 2, 2007 No comments | This post has 566 views.

Enabling cupsys Web Admin Interface

If you are trying to get your printing system going, and search for tips and docs on the web, you will find most of the documentation referring to http://localhost:631 as your cupsys administration interface. However, on Ubuntu, this browser-based administrative interface for cupsys is disabled by
default. Here’s how to enable it:
Select “System”->”Administration”->”Users and Groups” from the main menu on your desktop.
Select “Show all users” and/or “Show all groups”.
Add the user “cupsys” to the group “shadow” in the “groups” tab.

Restart cupsys by issuing the command:
sudo /etc/init.d/cupsys restart
IMPORTANT: I don’t know why the web admin interface was disabled in the first place – so please know that it is best to reverse all that you did once by
removing the user cupsys from the shadow group, and restarting cupsys, once your work with the interface is done.

If you want, from command line only:
sudo adduser cupsys shadow sudo passwd cupsys sudo /etc/init.d/cupsys restart

Adding a startup script to be run at bootup

Posted by cviorel on June 25, 2007 No comments | This post has 589 views.

So you have a script of your own that you want to run at bootup, each time
you boot up. This will tell you how to do that.
Write a script. put it in the /etc/init.d/ directory.
Lets say you called it FOO. You then run

sudo update-rc.d FOO defaults

1	sudo update-rc.d FOO defaults

You also have to make the file you created, FOO, executable, using

sudo chmod +x FOO

1	sudo chmod +x FOO

You can check out man update-rc.d for more information. It is a Debian
utility to install scripts. The option defaults puts a link to start FOO in
run levels 2, 3, 4 and 5. (and puts a link to stop FOO into 0, 1 and 6.)

Also, to know which runlevel you are in, use the runlevel command.

If you want to remove the script, just run:

sudo update-rc.d -f FOO remove

1	sudo update-rc.d -f FOO remove

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cviorel.com

Author Archives: cviorel - Page 12

HOWTO: Create a FTP server with user access (proftpd)

Prevent X.Org from Starting in Ubuntu

Enable cupsys Web Admin Interface

Adding a startup script to be run at bootup

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cviorel.com

Author Archives: cviorel - Page 12

HOWTO: Create a FTP server with user access (proftpd)

Prevent X.Org from Starting in Ubuntu

Enable cupsys Web Admin Interface

Adding a startup script to be run at bootup

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