How to disable root login and enable key authentication on Dedicated server?
Refer following steps to disable direct root login.
1. SSH into your server as root user.
2. Open file sshd_config in your favorite editor
pico /etc/ssh/sshd_config
3. Find the line
Protocol 2, 1
4. Uncomment line and change it to look like
Protocol 2
5. Now find the line
PermitRootLogin yes
6. And Uncomment libe and make it look like as
PermitRootLogin no
7. Save the file sshd_config file,
8. Restart SSH service
/etc/rc.d/init.d/sshd restart
Once root login disabled on server generate authentication key by using following steps.
1. Add user for example we will add user support
useradd support
2.Assigne user support in wheel group.
usermod -G wheel support
3. Set correct permission for sudoers files.
chmod 644 /etc/sudoers
4. Now open sudoers file and set followings line in sudoers file.
pico /etc/sudoers
# User privilege specification
root ALL=(ALL) ALL
# Same thing without a password
%wheel ALL=(ALL) NOPASSWD: ALL
5. Make sure that sudo file binery file is secure.
chmod 4111 /usr/bin/sudo
If you are not sure about sudo binery path then run commamd to confirm the path.
which sudo
6.Now create .ssh directory in support users home directory.
cd /home/support
mkdir .ssh
7. Now generate the key by using PuTTYgen software and save the key on your local machine as support.ppk file.
8. Create authorized_keys file in .ssh directory and copy content from file support.ppk to authorized_keys file.
9. Confirm permission and ownership for files.
cd /home
ll | grep support
The ownership shuold be
drwx—— 7 support support 4096 Jul 10 03:44 support
cd /home/support
ll | grep .ssh
drwxr-xr-x 2 root root 4096 Jul 12 3:34 .ssh/
ll .ssh
The ownership shoud be
drwxr-xr-x 2 root root 4096 Jul 12 03:22 ./
drwx—— 7 support support 4096 Jul 12 03:44 ../
-rw-r–r– 1 root root 224 Jul 12 03:40 authorized_keys
Note : Do not close current Shell until you are able to access server with the support.ppk key.
While creating new subdomain from cPanel we are missing cgi-bin directory. At that time refer following steps.
Login in to WHM and check the domains hosting account package allow “CGI Privilege” or not. If not then enable “CGI Privilege” by editing packages.
WHM >> Account Functions >> Modify An Account and select the user from list and check box following option.
CGI Privilege
And save the package. Now you will able to creaet subdomain with the cgi-bin directory.
Note : As well as plesae set “Y” in WHM >> Main >> Server Configuration >> Basic cPanel/WHM Setup >>CGI Script Alias section.
——————
CGI Script Alias * Automatically create a cgi-bin script alias. This setting can be individually overridden during account creation.
——————
While running following command.
mysqladmin -i3 pr
We are getting result.
056 | unauthenticated user | localhost | | Connect | | Reading from net |
To avoid such problem add following lines in /etc/my.cnf file to avoid access for unauthenticated user.
root@server [~]# pico /etc/my.cnf
skip-networking
skip-name-resolve
skip-host-cache
skip-locking
Now restart the mysql service and check mysql process logs again.
While uploading images we are receiving “Not a valid image” error message. To resolve error message refer following steps.
First login into Joomla admin section and check box following option.
Global Config > System
- restrict uploads = No
- check mime types = No
Second edit configuration.php file and change.
From
var $ftp_enable = ’1′;
To
var $ftp_enable = ’0′;
Third comment following line in php.ini file if you are using customize php.ini file (mostly used on SuExec server).
;upload_tmp_dir = tmp
And now try to upload the image.
