Almalinux9.2_en

1.Disabling SELinux First, disable selinux. selinux is a feature that improves auditing and security in Linux, but when enabled, it places considerable restrictions on the behavior of services and on what can be configured. Therefore, it is basically disabled in many cases. SELinux Operation Mode Enforcing : SELinux functionality is enabled and access control is enabled Permissive : SElinux will warn, but no access restrictions will be placed disabled : Both SElinux function and access control are disabled

Clamav (anti-virus software)Install 1.Clam AntiVirus Install Mail Server Install 1. Postfix 1.1 Install Install Postfix and build an SMTP server Mail Server : Postfix + Clamav + Amavisd+SpamAssassin 1.Real-time scanning of e-mails ①Amavisd ,Clamav Server install

1. .Obtain an SSL certificate ( Let's Encrypt ) Install the latest open ssl 1.1 advance preparation 1.Package management system Snappy installed Since the SSL certificate issuing tool "certbot" of Let's Encrypt is recommended to be installed using "snap" after 2021, install Snapd first.(Can also be installed the traditional way with dnf or yum) 2. Converting Apache to https Install the following just in case 3. SSL/TLS (Let's Encrypt) settings on the mail server 3.1 Obtaining a certificate for the mail server Obtain a certificate for the mail server, but it cannot be obtained in the same way as above, so the following with the "--standalone" option fails.

1.Apache2 Install , Virtual Host Configuration 1.1 Apache2 install 2. Use of CGI Scripts ①CGI availability check 3. PHP installation and configuration 4. Digest authentication with Apache2 Since Basic Authentication, a well-known authentication authorization method for http, sends authentication information in plain text, there is a risk of ID and password leakage if the packet is intercepted. On the other hand, Digest Authentication encrypts and transmits authentication information, so there is almost no risk of information leakage.

1.Website data backup 1-1.Backup under /var/www/html ①Create backup script file # cd /var/www/system # vi backup_html.sh 2.MySQL database backup ①Create backup script file # cd /var/www/system # vi db_my_backup.sh 3.Restore backup files under html ①Store HTML backup files in "/ (root)" directory 4.Restore Mysql backup file ①Save the database backup file to any directory and （In the example, the directory is "/var/www/backup/db_bak".）Extracting data

2. Vsftpd over SSL/TLSLS 2.1 Create self-signed certificates This work is not required if you are using a trusted, legitimate certificate such as Let's Encrypt. 3. File server installation with Samba Build a file server with access rights that requires user authentication with Samba. Installation Procedure ①Create shared folders with access rights that require user authentication ②Accessible group creation ③Creation of users belonging to accessible groups ④Configuration File Editing

1.SSH remote connection SSH is a service for connecting remotely to a server and is basically running immediately after the OS is installed, but the default settings are somewhat insecure. Here we will configure the default settings to increase the security of ssh connections. 1.1 SSH service configuration file changes

Logwatch , DiCe , Disk Usage Check Script

AlmaLinux 9.2 Install AlmaLinux OS is a project launched by CloudLinux in the US as an alternative to CentOS. Currently, the AlmaLinux OS Foundation is the development parent organization.Following the general availability of Red Hat Enterprise Linux 9.0, AlmaLinux 9.0 was released on May 26, 2022. Like Red Hat Enterprise Linux 9, AlmaLinux 9 utilizes the same package versions as the Linux 5.14 kernel, GCC 11, Python 3.9, and RHEL9. Cockpit web management interface, enhanced kernel live patching, improved container and cloud integration, OpenSSL 3, and other security improvements. This time we will install AlmaLinux 9.2 with a minor upgrade on May 11, 2023.

Mysql8 , WordPress Install WordPress Install 1. Create database for Word Press As an example, assume database [wp_db] database user [wp_user] password [?Ww123456]

Suricata SURICATA IDS/IPS is an open source IDS that monitors communications on the network and detects suspicious traffic. The basic mechanism is signature-based, so it can detect predefined unauthorized communications. Suricata is also characterized by its ability to provide protection as well as detection. Tripwire 1.Download and installation Chkrootkit ①Download and install chkrootkit

SSH connection with authentication using public key cryptography  Create public and private key pairs Create a public/private key pair for a user connecting to a Linux server using OpenSSH. Use ssh-keygen to create the key pair. The creation of a public/private key pair must be done as a user with remote login privileges. If you do not specify the destination and file name, id_ed25519 and id_ed25519.pub will be created in /home/(user name)/.ssh/. On the way, enter the password for the key.