SEC.01

The playbook

The run starts read-only: the recon probes decide what happens next. The steps that follow are adapted to the distribution and state found — a real machine is rarely clean.

1. 01recondoes the user exist? home folder and shell
2. 02reconkey location (AuthorizedKeysFile may be non-standard)
3. 03reconfingerprints of the current keys
4. 04reconis the new key valid? its SHA256 fingerprint
5. 05reconis the new key already present?
6. 06reconSELinux (restorecon needed on ~/.ssh)
7. 07actBack up the keysverify
8. 08actAdd the new keyverify
9. 09actFix owner and permissionsverify
10. 10actTest the new key (login by the user)verify
11. 11actRemove the old keys (only if remove_old = true and the test passed)destructiveverify

SEC.02

What it verifies

Each step ships its own check. The run only moves on when the check passes, so what the recipe reports as done is what is actually on the server.

1. 01verifyBack up the keysVerified byls -1 "$(getent passwd ${user} | cut -d: -f6)"/.ssh/authorized_keys.bak.*
2. 02verifyAdd the new keyVerified bygrep -cxF '${pubkey}' "$(getent passwd ${user} | cut -d: -f6)/.ssh/authorized_keys"
3. 03verifyFix owner and permissionsVerified byH=$(getent passwd ${user} | cut -d: -f6) && stat -c "%a %U" "$H/.ssh" "$H/.ssh/authorized_keys"
4. 04verifyTest the new key (login by the user)Verified byjournalctl --since '-15 min' --no-pager | grep 'Accepted publickey for ${user}'
5. 05verifyRemove the old keys (only if remove_old = true and the test passed)Verified byssh-keygen -lf "$(getent passwd ${user} | cut -d: -f6)/.ssh/authorized_keys"

SEC.03

Guardrails

Non-negotiable instructions the run must respect, whatever it finds on the server.

SEC.04

Variables

What you choose before launching — the recipe fills in the rest.

SEC.05

How a recipe runs in Servor

Servor is zero-knowledge: the platform cannot execute anything on its own. When you launch this recipe, a run reads the reconnaissance, plans the steps and asks for your approval. Each approved command is signed by your browser — with a key the server never sees — then relayed verbatim to the agent, which verifies the signature locally before executing.

SEC.06

Deploy on Servor button

Maintain SSH key rotation or a project that needs it? Put this button in your README or on your site: one click and your users install it on their own server.

SEC.07

More security recipes

1. 01Harden SSHTurns off password login and root password login, keeps keys. Destructive: verify your key access first.
2. 02fail2banfail2ban with the SSH jail on the right port, active and verified.
3. 03UFW firewallUFW: denies incoming by default, allows the real SSH port + chosen ports, with a safety net. Destructive: keeps SSH open.
4. 04Automatic security updatesEnables automatic security updates: unattended-upgrades (Debian/Ubuntu) or dnf-automatic (RHEL/Fedora).
5. 05CrowdSecCrowdSec collaborative IPS, SSH collections and firewall bouncer.