a3808842c1
server-setup.sh configured ufw and stopped there, which leaves SSH open
to unlimited password guessing and the kernel on defaults that are wrong
for an internet-facing host.
Adds three drop-in files, so a re-run replaces its own config and never
edits a distro file in place:
/etc/ssh/sshd_config.d/10-marketplaces-hardening.conf
password and keyboard-interactive auth off, root key-only,
no agent/X11 forwarding, MaxAuthTries 3, 30s login grace
/etc/fail2ban/jail.d/marketplaces.local
sshd, nginx-http-auth, nginx-bad-request; 5 in 10m, 1h ban
/etc/sysctl.d/99-marketplaces-hardening.conf
no redirects or source routing, rp_filter, SYN cookies,
forwarding off, restricted kernel pointers and dmesg
Both accounts on the host are key-only by construction - the deploy user
is created with no password at all - so disabling password auth cannot
lock anyone out. It only closes guessing against a credential nobody
intended to exist.
The sshd block runs `sshd -t` first and removes its own drop-in if the
test fails. A bad sshd config that takes effect on a remote box is how
people lock themselves out permanently.
DEPLOYMENT.md §3.2 documents all three plus the post-provision checks.
Not copied from the reference implementation: its hardcoded server IP.
Kept as-is because ours is already better: add-domain.sh pre-checks the
DNS A record and runs nginx -t before and after.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>