Sunday 10 September 2017

File/Directory Compression and Archiving with Zip

Compressed files use less disk space and download faster than large, uncompressed files. You can compress Linux files with one of the popular open-source compression tool Zip.

Friday 8 September 2017

How to Restrict PHP Information Leakage

By Default PHP installation exposes to the world that PHP is installed on the server. Need to modify the php.ini and set the expose_php variable to Off. For Centos/RHEL, the file is /etc/php.ini. This will remove the X-Powered-By line and PHP version.

Tuesday 5 September 2017

How to Setup Linux SSH Login Banner on Centos/RHEL 7

Most of the system administrator whenever configure Linux Servers always use login banner for sending a message before authentication. The banner contains some security warning information or general information. This option is only available for protocol version 2. By default, no banner is configured in SSH.

Sunday 3 September 2017

How to configure SFTP Server on Centos/RHEL - Multiple users

SSH File Transfer Protocol (SFTP) is application protocol designed to allow easily transfer files between computers. Many users prefer to use SFTP. SFTP provides file access, transfer, and management tools that resemble FTP through a secure SSH connection. However, SFTP is not merely FTP over SSH. Instead, it is an entirely separate protocol. 

Saturday 2 September 2017

How to Set Password Policy in /etc/login.defs on Centos/RHEL

The password aging controls and password length are defined in /etc/login.defs file. The password policy required to defining the number of days a password is valid, minimum length of a password, the strength of a password, and number of warning days before the password expires. To apply password policy, edit /etc/login.defs file and set PASS values.