A fresh Alma box has firewalld active, and the iptables-based harden-firewall.sh
refused to run there (caught by harden-ssh's '|| warn', so the host firewall was
silently skipped). Use firewalld natively on the rhel family instead of fighting it.
- harden-firewall.sh: family-aware backend. On rhel, apply/allow/deny/list/disable
drive firewall-cmd (deny-by-default zone, SSH + registered ports, ping policy,
source-restricted rich rules); Alpine/Debian keep the iptables engine unchanged.
FW_BACKEND=iptables|firewalld overrides.
- oslib: install_firewalld(); sshguard_backend() prefers sshg-fw-firewalld on rhel
so brute-force blocks land in firewalld (no INPUT->sshguard jump needed).
- Deployments already fall through to a firewall-cmd branch when the iptables
engine is absent, so they need no changes.
- README + script header document the per-family backend.
harden-ssh / harden-jumphost are unchanged -- they call harden-firewall.sh apply
and read sshguard_backend(), so the switch happens underneath them.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
57_Wolve
fe25f35305