diff --git a/documentation/audits/SPIKE-agent-pin-mismatch-2026-06-29.md b/documentation/audits/SPIKE-agent-pin-mismatch-2026-06-29.md new file mode 100644 index 0000000..06e0544 --- /dev/null +++ b/documentation/audits/SPIKE-agent-pin-mismatch-2026-06-29.md @@ -0,0 +1,203 @@ +# SPIKE — controller↔agent TLS leaf-pin mismatch (disk ops + quiesce backup dead) + +- **Date:** 2026-06-29 +- **Class:** Diagnostic / read-only. **No code, config, cert, service, or version change was made.** +- **Host:** felhom-pve (`demo-felhom`, 192.168.0.162), controller in **LXC 9201**. +- **Verdict:** **Hypothesis #1 — the agent local-API leaf was regenerated** during the root→non-root + agent migration on **2026-06-28 ~08:56 CEST**. The controller's pin (and `bootstrap.json` seed) + still reference the **pre-migration** leaf. A secondary blocker (empty token store) is latent + behind the pin and will surface the moment the pin is fixed. + +--- + +## 1. Live running versions + +| Component | Version / image | Notes | +|---|---|---| +| Host agent | **felhom-agent 0.43.0** | unit `felhom-agent.service`, runs **non-root** as `felhom-agent`, `--config /etc/felhom-agent/agent.json`, `ActiveEnterTimestamp = Sun 2026-06-28 08:59:06 CEST` | +| In-guest controller | **felhom-controller:0.89.0** | LXC 9201, `Up ~1h (healthy)` at probe time | + +--- + +## 2. The three fingerprints + +| Label | Value | Source | +|---|---|---| +| **AGENT_FP** (served now) | `ced34036440639f48f4b96fb1802e79b2c1b3102eb763d3ba97aea2da1944f9c` | on-disk `local-api.crt` **==** live wire (`s_client`) **==** boot log — all three agree | +| **PIN_FP** (controller pins) | `60b5974d586f5f3c8ec41eb998d0f07406178219c36bf6d3ff377570279d8245` | `controller.yaml → local_api.fingerprint` (data volume in 9201) | +| **SEED_FP** (bootstrap seed) | `60b5974d586f5f3c8ec41eb998d0f07406178219c36bf6d3ff377570279d8245` | `/etc/felhom-bootstrap/bootstrap.json → local_api.fingerprint` | + +`PIN_FP == SEED_FP == 60b5974d…` ≠ `AGENT_FP == ced34036…`. The controller is talking to the +**right endpoint** (both sides `192.168.0.162:8443`) and pinning a **consistent but now-obsolete** +leaf. + +--- + +## 3. Raw evidence + +### A — what the agent serves (host felhom-pve) + +**A1 — socket owner on :8443** (single process, not a stale/second daemon → hypothesis #3 ruled out): +``` +LISTEN 192.168.0.162:8443 users:(("felhom-agent",pid=3550072,fd=18)) +``` + +**A2 — unit + boot-log fingerprint history.** The leaf fingerprint logged at every boot is stable +`60b5974d…` from Jun 24 through Jun 27, then **flips to `ced34036…` on Jun 28 08:56:37**, same +cert path: +``` +Jun 26 19:54:50 local-api leaf ready fingerprint_sha256=60b5974d… cert=/var/lib/felhom-agent/local-api.crt +Jun 27 … (controller swaps to 0.86.0 / 0.87.0; leaf still 60b5974d) +Jun 28 08:56:37 local-api leaf ready fingerprint_sha256=ced34036… cert=/var/lib/felhom-agent/local-api.crt ← REGENERATED +Jun 28 08:59:06 local-api leaf ready fingerprint_sha256=ced34036… cert=/var/lib/felhom-agent/local-api.crt ← current daemon (pid 3550072) +``` +`ExecStart=/usr/local/bin/felhom-agent --config /etc/felhom-agent/agent.json`, +`FragmentPath=/etc/systemd/system/felhom-agent.service`, `ActiveEnterTimestamp=2026-06-28 08:59:06`. + +**A3 — on-disk leaf** (fresh, owned by the new non-root user, mtime = the switchover): +``` +-rw-r--r-- 1 felhom-agent felhom-agent 591 Jun 28 08:56 local-api.crt +-rw------- 1 felhom-agent felhom-agent 227 Jun 28 08:56 local-api.key +-rw------- 1 felhom-agent felhom-agent 0 Jun 28 08:56 local-tokens.log ← 0 bytes (see §6) +openssl … DER | sha256sum = ced34036440639f48f4b96fb1802e79b2c1b3102eb763d3ba97aea2da1944f9c +serial=85131255A9AE3FD902A5DB12A15D0459 notBefore=Jun 28 05:56:37 2026 GMT notAfter=Jun 25 05:56:37 2036 GMT +``` + +**A4 — on-the-wire leaf** (live `s_client` to 192.168.0.162:8443): +``` +ced34036440639f48f4b96fb1802e79b2c1b3102eb763d3ba97aea2da1944f9c +``` +→ **wire == disk == boot-log.** No stale/second process; one honest agent serving one fresh cert. + +**A5 — agent config `local_api`** (paths NOT overridden to anything unexpected; defaults): +```json +"local_api": { "enable": true, "listen_addr": "192.168.0.162:8443", + "cert_file": "/var/lib/felhom-agent/local-api.crt", + "key_file": "/var/lib/felhom-agent/local-api.key", + "token_store": "/var/lib/felhom-agent/local-tokens.log" } +``` + +**Surviving pre-migration leaf (the restore candidate).** A set-aside copy of the old root-era +`/var/lib` exists from the bundle migration test, and it **matches the controller pin exactly**: +``` +/root/agent-backup-bundle-test/aside-var-lib/local-api.crt + DER|sha256 = 60b5974d586f5f3c8ec41eb998d0f07406178219c36bf6d3ff377570279d8245 ← == PIN_FP == SEED_FP + notBefore=Jun 10 06:52:37 2026 GMT serial=8FFA15857DABD903BB53742E6EA2CE46 + (local-api.key present alongside) +``` + +### B — what the controller pins (LXC 9201) + +**B1 — `controller.yaml` `local_api`** (`/var/lib/docker/volumes/felhom-controller-data/_data/controller.yaml`): +```yaml +local_api: + endpoint: 192.168.0.162:8443 + fingerprint: 60b5974d586f5f3c8ec41eb998d0f07406178219c36bf6d3ff377570279d8245 + token: +``` + +**B2 — `bootstrap.json` seed** (`/etc/felhom-bootstrap/bootstrap.json`): +```json +"local_api": { "endpoint": "192.168.0.162:8443", + "fingerprint": "60b5974d586f5f3c8ec41eb998d0f07406178219c36bf6d3ff377570279d8245" } +``` + +**B3 — controller error log** (every 5 min, two distinct call sites): +``` +[quiesce] cycle error: check due: agentapi: GET /backup/due: … TLS pin mismatch: agent leaf SHA-256 does not match the bootstrap fingerprint +[web] disk list via agent failed: agentapi: GET /disks: … TLS pin mismatch: agent leaf SHA-256 does not match the bootstrap fingerprint +``` + +### C — endpoint sanity +`controller.yaml.endpoint` = `bootstrap.json.endpoint` = `agent listen_addr` = `192.168.0.162:8443`. +The controller pins the right host; only the leaf value is stale. Endpoint mismatch ruled out. + +--- + +## 4. Cert-regeneration ↔ agent-restart correlation + +The fresh leaf's `notBefore` (Jun 28 05:56:37 GMT = **08:56:37 CEST**, with the code's −1h skew +backdate) and the cert/key mtimes (Jun 28 08:56) coincide to the second with the first +post-migration `leaf ready` log line. The agent then settled into its current daemon at 08:59:06. +This is **not** an expiry event (10-year validity) — it is `EnsureLeaf` taking the *generate* branch +because the non-root agent's data dir (`/var/lib/felhom-agent`, now owned `felhom-agent:felhom-agent`) +contained **no** cert/key at first boot under the new user. The old pair was preserved only in the +`/root/agent-backup-bundle-test/aside-var-lib/` set-aside, so `EnsureLeaf` minted a new self-signed +leaf and persisted it — changing the served fingerprint out from under every already-issued pin. + +This is a direct side-effect of the **BUNDLE Day-0 / root→non-root agent migration on 2026-06-28**. + +--- + +## 5. Listening-socket owner + +Single process: `felhom-agent` pid **3550072** (the running daemon), bound to `192.168.0.162:8443`. +No second/stale listener. Hypothesis #3 (stale process serving an old cert) is **disproven** — and +note the *direction* is the opposite of #3 anyway: the live process serves the **new** cert, while +the **old** value is the one frozen in the controller's pin. + +--- + +## 6. Matched matrix row + conclusion + +Matrix row **#1 — agent leaf regenerated** (files were absent at the new non-root path; not a path +typo, not an expiry): + +> A3 == A2 == fresh mtime (cert regenerated 2026-06-28 ~08:56, the agent redeploy/non-root switch); +> `PIN_FP` ≠ `AGENT_FP`; a surviving backup cert matching `PIN_FP` **does** exist +> (`…/aside-var-lib/`, fp `60b5974d…`). + +**Root cause (high confidence):** the root→non-root agent migration on 2026-06-28 reinitialised +`/var/lib/felhom-agent` without carrying over the existing leaf, so the agent generated a new +self-signed local-API leaf (`ced34036…`). The in-guest controller (and its `bootstrap.json`) still +pin the pre-migration leaf (`60b5974d…`), so the pinned `agentapi` client fails closed on every +call. Because **all** disk/storage/backup traffic goes through that one pinned client, both the disk +UI **and** the quiesce app-consistent-backup loop are down. + +**Note — this is NOT a stale controller re-merge (#2).** `PIN_FP == SEED_FP`, so re-running the +controller's bootstrap/`ensureLocalAPI` merge would re-apply the **same obsolete** `60b5974d…` and +not help. The divergence originated on the agent side, not from a stale seed re-merge. + +### Secondary blocker (latent behind the pin) — empty token store +`/var/lib/felhom-agent/local-tokens.log` is **0 bytes**, mtime **2026-06-28 08:56** (reset at the +same migration). The controller's per-guest bearer token was minted into the *pre-migration* store. +The TLS pin fails first (handshake), so this is currently masked — but once the pin is corrected the +agent will have **no token entry** for guest 9201 and authenticated calls will **401**. This matches +the known "local-API 401 until token re-seed after agent restart / stale token map" pattern. **Any +remedy below must be paired with re-seeding the guest token** (re-provision token mint, or restore +the old token store), or the symptom merely changes from `TLS pin mismatch` to `401`. + +--- + +## 7. Remedy options for the operator (NOT executed — operator's choice) + +| # | Remedy | Effect | Trade-offs / cautions | +|---|---|---|---| +| **R1** | **Restore the pre-migration leaf**: copy `…/aside-var-lib/local-api.{crt,key}` → `/var/lib/felhom-agent/`, `chown felhom-agent:felhom-agent`, `0644/0600`, restart agent | Agent serves `60b5974d…` again → matches existing `PIN_FP`+`SEED_FP`; **zero controller-side change** | Lowest blast radius. Verify the **non-root** user can read both files; restart now *loads* (files present) so it mints nothing new. Does **not** fix the token store. | +| **R2** | **Re-pin the controller** to `ced34036…`: set `controller.yaml.local_api.fingerprint` (and `bootstrap.json`) to AGENT_FP, restart controller | Keeps the freshly-generated leaf; controller trusts the current agent | Edits in-guest config; keeps the "current cert" as canonical, which is the cleaner long-term state if the migration intends a new leaf. Does **not** fix the token store. | +| **R3** | **Re-bootstrap / re-provision the controller** against the live agent | Re-mints token **and** re-pins fingerprint from a freshly emitted `bootstrap.json` | Heaviest; resolves the token-store blocker too — but only correct if a fresh `bootstrap.json` carrying AGENT_FP is generated (the *existing* one still holds the stale `60b5974d…` and must be regenerated, not reused). | + +**Token store (applies to R1/R2):** also re-seed guest 9201's bearer token into +`/var/lib/felhom-agent/local-tokens.log` (re-provision token mint, or restore the old token store +from the same `aside-var-lib` set-aside if present), else expect a `401` after the pin is fixed. + +**Forward-looking:** the root→non-root migration runbook should **carry the existing +`local-api.{crt,key}` and `local-tokens.log` into the new data dir** (or treat their loss as a +re-bootstrap trigger). Regenerating the leaf silently invalidates every issued pin — exactly this +incident. + +--- + +## 8. Confidence + gaps + +- **Pin root cause: very high.** Disk == wire == boot-log all agree; mtime/`notBefore` pin the + regeneration to the migration minute; the matching pre-migration backup leaf proves the old value. +- **Token-store secondary blocker: high (inferred, not yet triggered).** The 0-byte store at the + migration mtime is strong evidence; not *proven* live because the TLS pin fails before any token is + evaluated, and probing it would require an authenticated call (out of scope for read-only). Operator + should expect it and plan the token re-seed alongside whichever pin remedy is chosen. +- **Not assessed:** whether `…/aside-var-lib/` also holds the matching pre-migration + `local-tokens.log` (would make R1 + token restore a single copy). Cheap to check before choosing. + +*No secrets recorded: the per-guest bearer token is referenced as "stored out-of-band"; the leaf +fingerprint is not a secret.*