Linux Security Toolkit

Linux Permissions Calculator converts between chmod's three notations — checkboxes, octal (755), and symbolic (rwxr-xr-x) — including the setuid, setgid, and sticky bits, with the exact chmod command ready to copy. Thinking in terms of a change rather than a final state? chmod Command Generator builds the symbolic command — u+rwx, g-w, o=r — from clauses instead, including -R, -c, and -v. Setting a default for permissions rather than one file's? umask Calculator converts a umask to the permissions new files and directories actually get, and back. Reviewing who can run what as root? Sudoers File Analyzer flags NOPASSWD: ALL grants, wildcard command specs, and well-known privilege-escalation binaries granted unrestricted. Locking down the network side? Firewall Rule Generator builds a complete UFW or firewalld command sequence — with SSH always ordered safely before the firewall enables — and fail2ban Jail Config Validator checks a jail.local file for ban times too short to matter and ignoreip ranges broad enough to disable it entirely. Setting up a whole server rather than one setting? Linux Hardening Checklist Generator builds a downloadable checklist covering updates, SSH, the firewall, user permissions, and logging — with commands specific to Ubuntu, Debian, Fedora, or RHEL.