2022-11

SSH connection with authentication using public key cryptographyCreation of public and private key pairsCreate a public/private key pair for a user connecting to the Linux server using OpenSSH.Use ssh-keygen to create key pairs.Creation of public/private key pairs is performed with remote login user privileges。If you do not specify the destination and file name, id_ed25519 and id_eed25519.pub will be created in /home/(user name)/.ssh/. On the way, enter the password for the key.

Rocky Linux9.0The Rocky Release Engineering team announced the latest version of Rocky Linux 9.0 on July 14, 2022.Rocky Linux is a Linux distribution compatible with Red Hat Enterprise Linux; Rocky Linux 9 is a compatible release with RHEL 9 released in May and will be supported until the end of May 2032.In security, password-based root user authentication via SSH is now disabled by default.SSH keys can be used to access remote systems instead of root passwords.OpenSSL supports version 3.0.1, enhanced support for HTTPS clients, and a new FIPS module.

1.Disabling SELinuxFirst, 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 operating modesEnforcing : SELinux functionality is enabled and access control is enabledPermissive : SElinux will warn, but no access restrictions will be placeddisabled : Both SElinux function and access control are disabled2.System ModernizationPackage updates are performed as soon as possible immediately after OS installation.However, when a dnf update is performed, a kernel update is also performed at the same time.A kernel update may require rebooting the system or stopping services, or worse, a kernel panic may occur and the system may not boot. It is wiser to exclude the kernel from the update.The kernel can be excluded from updates by running dnf -y update with "--exclude=kernel*" after it.