diff --git a/docs/ssh-host-certificate-design.md b/docs/ssh-host-certificate-design.md index a905cc8..cf34227 100644 --- a/docs/ssh-host-certificate-design.md +++ b/docs/ssh-host-certificate-design.md @@ -1,6 +1,6 @@ # SSH host-certificate design — killing per-boot TOFU (F-02 / P-17) -> Status: **BENCH-VERIFIED end-to-end 2026-07-11** (`comet-beacon-54`, real TPM): +> Status: **BENCH-VERIFIED end-to-end 2026-07-11 on clean build `28d31e4`** (`comet-beacon-54`, real TPM): > TPM-mTLS → broker → step-ca signing → cert install → admin login **by FQDN with > no TOFU**, and per-boot auto-re-sign across a reboot. Closes SAR finding **F-02** > / POA&M **P-17**. Signing is **broker-mediated** (host → enrol-broker host plane → @@ -122,6 +122,13 @@ automatically. **SELinux confinement is clean** (no AVCs writing `/etc/ssh` + reloading sshd → **no local TE module needed**), and STIG crypto policy accepts the `ecdsa-sha2-nistp256-cert-v01` host cert. +**Re-verified on the rebuilt `28d31e4` image (2026-07-11), not hand-patched:** the +auto-derived FQDN principal (`.`) is baked, so admin login by FQDN +with no TOFU **survives a reboot with zero manual steps** — the exact case the +hand-fixed host regressed on (its manual `SSH_HOSTCERT_PRINCIPALS` edit lived on the +RAM overlay and evaporated). F-02/P-17 is closed on a real build, not just a +hand-fixed host. + Getting there surfaced defects, all fixed on `poam-hardening` (`28d31e4`): | # | Defect (as seen on the bench) | Fix | diff --git a/docs/ssp-annex-a-ism-residual-risk.md b/docs/ssp-annex-a-ism-residual-risk.md index 779c6eb..8d2dc83 100644 --- a/docs/ssp-annex-a-ism-residual-risk.md +++ b/docs/ssp-annex-a-ism-residual-risk.md @@ -115,7 +115,7 @@ ISM/PSPF style). Ratings are **pre-treatment** unless stated; the AO accepts the | Strong machine authentication | ISM-1546*, ISM-0974* | Mutual, certificate-based auth. | **802.1X EAP-TLS**, client key non-exportable in **TPM** (`0x81000100`), cert in TPM NV. The **management-plane agent reuses the same TPM identity** for mTLS (`RequireAndVerifyClientCert` to the fleet CA; server keys inventory off the verified cert serial). One non-exportable key = 802.1X + NVMe hostnqn + agent stream. | Partial | R-01 (not bench-verified; disabled in test builds), R-08 (placeholder CA), R-14 (mgmt plane = connected system) | | Privileged access restricted | ISM-1507*, ISM-0445* | Limit & control admin access. | Single key-only `wheel` admin; root login disabled; admin **confined to `staff_u`** with a sudo `sysadm_r`/`sysadm_t` role/type transition (SELinux context elevates on privilege use). | Partial | R-05 | | Secure remote administration | ISM-1506*, ISM-1232* | Hardened admin channel. | SSH **key-only**, password & keyboard-interactive off, hardened ciphers/MACs/KEX (STIG crypto policy; ECDSA/RSA keys — ed25519 excluded by policy). | Implemented | — | -| Administrative host-key trust (SSH host certs) | ISM-1506*, ISM-1091* | Admins can verify host identity (no persistent TOFU). | Ephemeral overlay ⇒ new sshd host keys each boot; each host's per-boot key is **signed into an OpenSSH host certificate by the fleet SSH CA** at boot, brokered via the **enrol-broker host plane** over **TPM-identity mTLS** (`fleet-ssh-hostcert`). Admins trust one **`@cert-authority`** line; step-ca stays behind the broker; client **fails open** to a bare key if unreachable (no admin lock-out). **Implemented + bench-verified 2026-07-11** (comet-beacon-54: FQDN login/no-TOFU, per-boot re-sign, SELinux clean). | Implemented | **R-16** | +| Administrative host-key trust (SSH host certs) | ISM-1506*, ISM-1091* | Admins can verify host identity (no persistent TOFU). | Ephemeral overlay ⇒ new sshd host keys each boot; each host's per-boot key is **signed into an OpenSSH host certificate by the fleet SSH CA** at boot, brokered via the **enrol-broker host plane** over **TPM-identity mTLS** (`fleet-ssh-hostcert`). Admins trust one **`@cert-authority`** line; step-ca stays behind the broker; client **fails open** to a bare key if unreachable (no admin lock-out). **Implemented + bench-verified 2026-07-11 on clean build `28d31e4`** (comet-beacon-54: FQDN login/no-TOFU, **survives reboot unattended**, SELinux clean). | Implemented | **R-16** | | No default/shared credentials | ISM-1304* | No baked credentials. | No per-host secrets in any artifact; identity from TPM at runtime; `machine-id` empty; host keys regenerated at first boot. | Implemented | — | | MFA for privileged users | ISM-1173*, ISM-1504* | MFA on privileged access. | Machine auth is cert+TPM (strong). **Human admin MFA on the management-plane UI now enforced via WebAuthn passkeys** (phishing-resistant, origin-bound, hardware-backed — the manager's admin plane, v0.3). Host **SSH** admin remains key-only (no separate human MFA). | Partial (host SSH) / Implemented (mgmt UI) | R-05 | | Passwordless appliance accounts | — (STIG #10) | Account lockout/aging. | `kiosk`/`fleetadmin` are key-only; password aging/faillock **exempted for these two only**, full policy system-wide otherwise. | Implemented | R-05 (folds into rotatable-access roadmap) | @@ -208,7 +208,7 @@ asked to accept. Treatments map to [docs/TODO.md](TODO.md) (working POA&M). | **R-12** | **No formal Incident Response Plan**; volatile RAM overlay complicates live forensics. | 2.1, 2.6 (ISM-0043*/0109*) | Possible × Moderate → **Medium** | Inherent recovery (reboot → verified state; revert digest); centralised logs survive host wipe. | Author IRP + log-retention + break-glass/forensics procedure suited to stateless hosts. | **Low** | SecOps — *before production* | | **R-14** | **Management/enrolment plane is a connected system, built but not yet separately authorised.** The host now trusts + streams to the fleet-manager and enrols via the broker + **step-ca fleet CA** (a new trust anchor + key material); the broker exposes **one unauthenticated pre-auth CSR endpoint**; InfluxDB holds telemetry + a bearer token. These server-side controls (CA key protection, broker hardening, admin-plane exposure, data-at-rest) are outside this SSP's boundary. | 2.4, 2.5, 2.6, 2.9 (ISM-1546*/1483*/0501*) | Possible × Moderate → **Medium** | Host-side exposure is limited: **outbound-only** mTLS, TPM-bound identity, **read-only** telemetry (no user data), and **commands logged-not-applied in v1**. Broker enrolment is human-anchored (OOB fingerprint + admin mTLS approve; no auto-approval). Mgmt-plane admin UI behind passkey MFA. | Author a **separate SSP/authorisation** for the management plane (CA key protection, broker endpoint hardening + rate-limiting, InfluxDB token/data protection, admin-plane network exposure); TLS everywhere is already in place on this plane. | **Low–Medium** | Platform/SecOps — *before the mgmt plane is production* | | **R-15** | **Deferred agent reconcile actuators.** v1 receives `DesiredState`/`Command` but **only logs** them; when actuation (apply `kiosk_url` / `reboot` / drain) is built, `fleet-agent` becomes a **remote host-mutation channel**. | 2.5 (ISM-1483*/1509*) | Rare × Moderate → **Low** (v1) | v1 performs **no host mutation** — the receive path is inert; the command authZ path (server-authoritative desired-state, verified over mTLS) is designed but not exercised. | At build time, assess the command/authZ path (who can set desired-state, replay/authZ, blast radius of `reboot`/drain) before enabling actuators; keep it behind an explicit flag. | **Low** | Platform team — *at actuator build* | -| **R-16** | Per-boot SSH host keys made admin SSH **perpetual TOFU** — a host key can never be pinned, so a LAN MITM of admin SSH is client-undetectable. **Remediated 2026-07-11** (`poam-hardening`): broker-mediated **SSH host certificates**. | 2.4, 2.9 (ISM-1506*/1091*) | Possible × Moderate → **Medium** (pre-fix) | Each per-boot key is **signed by the fleet SSH CA** via the enrol-broker host plane (TPM-mTLS); admins trust one **`@cert-authority`** line; step-ca behind the single front door; client **fails open** to a bare key (no lock-out) if broker/CA unreachable. | **Bench-verified 2026-07-11** (comet-beacon-54: FQDN login/no-TOFU, per-boot re-sign across reboot, SELinux clean). Remaining: broker-side principal validation (defence-in-depth) + roll the `@cert-authority` anchor to admins. Design B deferred, not required. | **Low** | Platform team — *done; roll anchor* | +| **R-16** | Per-boot SSH host keys made admin SSH **perpetual TOFU** — a host key can never be pinned, so a LAN MITM of admin SSH is client-undetectable. **Remediated 2026-07-11** (`poam-hardening`): broker-mediated **SSH host certificates**. | 2.4, 2.9 (ISM-1506*/1091*) | Possible × Moderate → **Medium** (pre-fix) | Each per-boot key is **signed by the fleet SSH CA** via the enrol-broker host plane (TPM-mTLS); admins trust one **`@cert-authority`** line; step-ca behind the single front door; client **fails open** to a bare key (no lock-out) if broker/CA unreachable. | **Bench-verified 2026-07-11 on clean build `28d31e4`** (comet-beacon-54: FQDN login/no-TOFU, **survives reboot unattended** — auto-derived FQDN principal, not a manual edit; SELinux clean). Remaining: broker-side principal validation (defence-in-depth) + roll the `@cert-authority` anchor to admins. Design B deferred, not required. | **Low** | Platform team — *done; roll anchor* | | **R-17** | **Time source was unauthenticated** (DHCP-handed NTP, no NTS) — an attacker spoofing DHCP/NTP could shift the clock to make expired/revoked certs validate (time feeds EAP-TLS, agent mTLS, future log TLS). **Remediated 2026-07-11** (`secure-ntp`): **NTS (RFC 8915)**. | 2.9 (ISM-1453*/1139*) | Possible × Moderate → **Low–Medium** (pre-fix) | Serving NTP presents a **fleet-CA-signed** NTS-KE cert; host (`secure_ntp=true`) verifies against `radius-ca.pem` and **no longer mixes in** the unauthenticated DHCP source; server name derived from the DHCP domain (no baked FQDN). A spoofer can only **DoS**, not shift time. Compensating meanwhile: isolated LAN + cert-serial inventory gate. | **Bench-verify** `chronyc authdata` NTS cookies, tcp/4460, cold-clock `nocerttimecheck`, STIG chrony compat; issue the per-environment NTS server cert (F-03/P-18 M3). | **Low** | Platform team — *bench-verify* | ### 3.1 Risk heatmap (post-treatment targets) diff --git a/docs/ssp.md b/docs/ssp.md index 6ae47f5..fc99166 100644 --- a/docs/ssp.md +++ b/docs/ssp.md @@ -18,7 +18,7 @@ | Version | 0.4 (DRAFT — pre-assessment) | | Date | 2026-07-11 | | Author / maintainer | System Owner (delegate) | -| Status | Lab / pre-production. STIG hardening applied + bench-verified; **UEFI Secure Boot signing verified enforcing on real hardware** (VM HTTP + EliteBook 820 PXE); secure path (802.1X/MACsec) not yet bench-verified. **v0.3 adds the fleet-management plane** (on-host `fleet-agent` telemetry over TPM-mTLS — bench-verified on hardware 2026-07-10; server-side manager with **WebAuthn-passkey** admin MFA + TPM enrolment broker) and July hardening changes (three local SELinux modules; fapolicyd overlay exec-guard fix). **v0.4** adds two host-identity/time hardening features (both implemented 2026-07-11): broker-mediated **SSH host certificates** (F-02/P-17 — **bench-verified 2026-07-11** on `comet-beacon-54`) and **NTS authenticated time** (F-03/P-18 — bench-verify pending). | +| Status | Lab / pre-production. STIG hardening applied + bench-verified; **UEFI Secure Boot signing verified enforcing on real hardware** (VM HTTP + EliteBook 820 PXE); secure path (802.1X/MACsec) not yet bench-verified. **v0.3 adds the fleet-management plane** (on-host `fleet-agent` telemetry over TPM-mTLS — bench-verified on hardware 2026-07-10; server-side manager with **WebAuthn-passkey** admin MFA + TPM enrolment broker) and July hardening changes (three local SELinux modules; fapolicyd overlay exec-guard fix). **v0.4** adds two host-identity/time hardening features (both implemented 2026-07-11): broker-mediated **SSH host certificates** (F-02/P-17 — **bench-verified 2026-07-11** on `comet-beacon-54`, clean build `28d31e4`) and **NTS authenticated time** (F-03/P-18 — bench-verify pending). | | Companion documents | [Annex A — ISM control cross-reference & residual risk](ssp-annex-a-ism-residual-risk.md); [Architecture design v2](diskless-fleet-design-v2.pdf); [Design errata](design-v2-errata.md); [Fleet-management design](fleet-management-design.md); [TPM enrolment design](tpm-enrolment-design.md); [STIG deviation register](stig-deviations.md); [Backlog / POA&M source](TODO.md) | > **Currency caveat (read before relying on control numbers).** This SSP and its @@ -410,7 +410,7 @@ production ATO: | R-13 | **Boot-chain signing not yet the standing default.** Signing + Secure Boot enforcement **verified end-to-end on hardware** (VM HTTP UKI 2026-06-20; 820 PXE signed iPXE→UKI 2026-06-22), but unsigned/SB-OFF lab builds are still possible (CI signs only when `SB_KEY`/`SB_CERT` are set) and not all hosts have `db` enrolled. | **Low** | Treat — make signed + Secure-Boot-on the default for all production builds/hosts (set CI secrets; enrol `db` fleet-wide). | | R-14 | **Management/enrolment plane is a connected system, built but not yet separately authorised.** The host now trusts + streams to the fleet-manager and enrols via the broker/**step-ca fleet CA** (a new trust anchor + key material) whose one **unauthenticated pre-auth CSR endpoint** is a new server-side surface. Host-side exposure is limited (outbound-only mTLS, read-only telemetry, commands logged-not-applied in v1). | **Medium** | Treat — separate SSP/authorisation for the management plane (CA key protection, broker endpoint hardening, InfluxDB token/data, admin-plane exposure). | | R-15 | **Deferred agent reconcile actuators.** v1 receives `DesiredState`/`Command` but only logs them; when actuation (apply kiosk_url / reboot / drain) is built, the agent becomes a **remote host-mutation channel** needing re-assessment. | **Low** (v1) | Treat at build time — assess the command/authZ path before enabling actuators. | -| R-16 | Per-boot SSH host keys made admin SSH perpetual **TOFU** (LAN MITM client-undetectable). **Remediated 2026-07-11**: broker-mediated **SSH host certificates** (`enable_ssh_hostcert=true`) — per-boot key signed by the fleet SSH CA via the enrol-broker host plane (TPM-mTLS); admins trust one `@cert-authority` line. **Bench-verified 2026-07-11** (comet-beacon-54: FQDN login, no TOFU; per-boot re-sign across reboot; SELinux clean). | **Low** | Treat — roll the `@cert-authority` anchor to admins; broker-side principal validation is a defence-in-depth TODO (F-02/P-17). | +| R-16 | Per-boot SSH host keys made admin SSH perpetual **TOFU** (LAN MITM client-undetectable). **Remediated 2026-07-11**: broker-mediated **SSH host certificates** (`enable_ssh_hostcert=true`) — per-boot key signed by the fleet SSH CA via the enrol-broker host plane (TPM-mTLS); admins trust one `@cert-authority` line. **Bench-verified 2026-07-11 on clean build `28d31e4`** (comet-beacon-54: FQDN login by name, no TOFU, **survives reboot unattended**; SELinux clean). | **Low** | Treat — roll the `@cert-authority` anchor to admins; broker-side principal validation is a defence-in-depth TODO (F-02/P-17). | | R-17 | Time source was **unauthenticated** (DHCP-handed NTP) — the clock feeds every certificate-validity decision. **Remediated 2026-07-11**: **NTS** (RFC 8915, `secure_ntp=true`) — fleet-CA-signed NTS-KE cert verified against `radius-ca.pem`; server name derived from the DHCP domain (no baked FQDN); a spoofer can only DoS. **Bench-verify pending.** | **Low** (once verified) | Treat — bench-verify `chronyc authdata` cookies + tcp/4460 + cold-clock + STIG chrony; issue the per-env NTS cert (F-03/P-18). | Each is detailed, ISM-cross-referenced, rated and assigned a treatment in Annex A.