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. 01recondistro and OpenSSH version
2. 02reconeffective SSH config (UsePAM yes required)
3. 03reconsshd PAM auth stack (common-auth or password-auth) and 2FA already wired?
4. 04reconPAM module already installed?
5. 05reconthe user exists, has an authorized key (mandatory) and has already enrolled TOTP?
6. 06reconaccounts without a key: they will no longer be able to log in (publickey becomes mandatory)
7. 07reconis sshd_config.d included? existing drop-ins
8. 08reconSELinux enforcing (RHEL): watch for denials after testing
9. 09actEnable EPEL (RHEL/Rocky/Alma only)verify
10. 10actInstall the PAM moduleverify
11. 11actEnroll TOTP (done by the user)verify
12. 12actBack up PAM and sshd_configverify
13. 13actInclude sshd_config.d (only if the Include is missing)verify
14. 14actRequire key + TOTP in sshddestructiveverify
15. 15actReload sshd (without dropping sessions)destructiveverify
16. 16actWire TOTP into the sshd PAM stackdestructiveverify

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. 01verifyEnable EPEL (RHEL/Rocky/Alma only)Verified bydnf repolist enabled | grep -ci epel
2. 02verifyInstall the PAM moduleVerified bycommand -v google-authenticator
3. 03verifyEnroll TOTP (done by the user)Verified bytest -s "$(getent passwd ${user} | cut -d: -f6)/.google_authenticator" && echo enrolled
4. 04verifyBack up PAM and sshd_configVerified byls -1 /etc/pam.d/sshd.bak.* /etc/ssh/sshd_config.bak.*
5. 05verifyInclude sshd_config.d (only if the Include is missing)Verified bygrep -cE '^\s*Include\s+/etc/ssh/sshd_config.d/' /etc/ssh/sshd_config && sshd -t && echo ok
6. 06verifyRequire key + TOTP in sshdVerified bysshd -t && sshd -T | grep -Ei '^(authenticationmethods|passwordauthentication) '
7. 07verifyReload sshd (without dropping sessions)Verified bysystemctl is-active ssh.service sshd.service ssh.socket 2>/dev/null | grep -c '^active'
8. 08verifyWire TOTP into the sshd PAM stackVerified bygrep -cE '^auth\s+required\s+pam_(google_authenticator|permit)\.so' /etc/pam.d/sshd

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 2FA (TOTP) 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.