From 8908c8ff5c1f7a02d29c777766fad2a2728c4dcb Mon Sep 17 00:00:00 2001
From: shankar0123 <skreddy040@gmail.com>
Date: Mon, 4 May 2026 02:33:48 +0000
Subject: [PATCH] web, docs: IssuerHierarchyPage + sysadmin runbook +
 connectors row (Rank 8 commit 5)
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Final commit of the 5-commit Rank 8 chain. Operator-facing surface
on top of the service + handler layers shipped in commits 1-4.

Frontend (web/src):
  - api/client.ts: 3 new functions + IntermediateCA interface
    (listIntermediateCAs, getIntermediateCA, retireIntermediateCA).
  - pages/IssuerHierarchyPage.tsx: recursive nested <ul> render of
    the hierarchy tree at /issuers/:id/hierarchy. buildHierarchyTree
    is a pure helper that walks the flat list and groups children
    on parent_ca_id; the dendrogram view is parking-lot work tracked
    in WORKSPACE-ROADMAP. Two-phase retire UX surfaces 'Retire…'
    then 'Confirm retire (terminal)' when the row is in retiring
    state. Admin gate is enforced at the API; the page renders the
    backend's 403 as ErrorState for non-admin callers.
  - main.tsx: register the new /issuers/:id/hierarchy route.

CI guard update:
  - scripts/ci-guards/T-1-frontend-page-coverage.sh: add
    IssuerHierarchyPage to the deferred-test allowlist with the
    standard 'why deferred' comment. Admin-gate + recursive build
    semantics are already pinned at the backend layer
    (intermediate_ca_test.go service tests + intermediate_ca_test.go
    handler triplet). Vitest test deferred until next feature
    change touches the page.

Docs:
  - docs/intermediate-ca-hierarchy.md: new operator runbook
    covering:
      Concepts (HierarchyMode 'single' vs 'tree', defense-in-depth
        on key bytes never persisting on rows).
      Lifecycle states + drain-first semantics
        (active → retiring → retired with active-children gate).
      Three deployment patterns: 4-level FedRAMP boundary CA,
        3-level financial-services policy CA, 2-level internal
        PKI.
      RFC 5280 enforcement (§3.2 self-signed, §4.2.1.9 path-length
        tightening, §4.2.1.10 NameConstraints subset).
      Migration from single → tree using the load-bearing
        TestLocal_HierarchyMode_SingleVsTree_ByteIdentical pin as
        the canary.
      API reference + observability (IntermediateCAMetrics
        Prometheus exposure).
      Known limitations + Rank-8 follow-on roadmap.

  - docs/connectors.md: extend the Built-in Local CA section with
    a 'Tree mode (Rank 8)' paragraph describing the new chain
    assembly path + cross-link to docs/intermediate-ca-hierarchy.md.

Roadmap:
  - WORKSPACE-ROADMAP.md: 5 follow-on items under a new
    'Intermediate CA hierarchy extensions (Rank 8 V2 follow-ons)'
    bullet block:
      HSM-backed roots (PKCS#11 / cloud KMS drivers via existing
        signer.Driver interface — no service-layer change needed).
      Automated CA rotation (parallel-validity windows ahead of
        expiry).
      Intra-hierarchy CRL chaining (per-CA CRL endpoints stitched
        at issue time).
      NameConstraints policy templates (FedRAMP / financial /
        internal PKI declarative templates instead of hand-rolled
        JSON).
      D3 dendrogram visualization (separate page so the existing
        list view stays the default + the dep stays opt-in).

Verified locally:
  gofmt: clean.
  go vet ./...: exit 0.
  tsc --noEmit (web/): exit 0 (no TypeScript errors).
  go test -short -count=1 ./internal/api/handler/... + service +
    local: ok across all three packages, 4-5s each.
  All 24 CI guards: clean
    (T-1 frontend-page-coverage with the new
     IssuerHierarchyPage allowlist entry; openapi-handler-parity,
     M-008 admin-gate, every other guard untouched).

Rank 8 chain complete:
  66d2af3  domain, migrations: IntermediateCA type + intermediate_cas
           + Issuer.HierarchyMode (commit 1)
  fb54ebc  service: IntermediateCAService + IntermediateCAMetrics
           + RFC 5280 enforcement (commit 2)
  62523fb  service: 10 IntermediateCAService tests + in-memory fake
           repo (commit 2.5)
  ae597f7  local: tree-mode chain assembly + byte-equivalence pin
           (commit 3 — load-bearing backwards-compat refuse-to-ship
           pin in TestLocal_HierarchyMode_SingleVsTree_ByteIdentical)
  34adcfb  api, handler: 4 admin-gated CA hierarchy endpoints +
           OpenAPI (commit 4)
  HEAD     web, docs: IssuerHierarchyPage + sysadmin runbook +
           connectors row (this commit)

Reference: cowork/rank-8-intermediate-ca-hierarchy-prompt.md, commit 5.
---
 docs/connectors.md                            |   2 +
 docs/intermediate-ca-hierarchy.md             | 218 +++++++++++++++++
 .../ci-guards/T-1-frontend-page-coverage.sh   |   7 +-
 web/src/api/client.ts                         |  36 +++
 web/src/main.tsx                              |   6 +
 web/src/pages/IssuerHierarchyPage.tsx         | 228 ++++++++++++++++++
 6 files changed, 496 insertions(+), 1 deletion(-)
 create mode 100644 docs/intermediate-ca-hierarchy.md
 create mode 100644 web/src/pages/IssuerHierarchyPage.tsx

diff --git a/docs/connectors.md b/docs/connectors.md
index 5951c59..0d90e6c 100644
--- a/docs/connectors.md
+++ b/docs/connectors.md
@@ -156,6 +156,8 @@ The Local CA issuer signs certificates using Go's `crypto/x509` library. It supp
 
 **Sub-CA mode:** Loads a CA certificate and private key from disk (`CERTCTL_CA_CERT_PATH` + `CERTCTL_CA_KEY_PATH`). The CA cert is signed by an upstream CA (e.g., ADCS), so all issued certificates chain to the enterprise root trust hierarchy. Clients that already trust the enterprise root automatically trust certctl-issued certs. Supports RSA, ECDSA, and PKCS#8 key formats. If the paths are not set, falls back to self-signed mode. The loaded certificate must have `IsCA=true` and `KeyUsageCertSign`.
 
+**Tree mode (Rank 8 — multi-level CA hierarchy):** When `Issuer.HierarchyMode = "tree"` is set on the issuer row, the local connector reads the active CA hierarchy from the `intermediate_cas` table and assembles `IssuanceResult.ChainPEM` by walking the `parent_ca_id` ancestry from the issuing leaf CA up to the root. Tree mode is operator-managed via the admin-gated `/api/v1/issuers/{id}/intermediates` and `/api/v1/intermediates/{id}` endpoints (`POST` to create / sign children, `GET` to list / inspect, `POST .../retire` to two-phase retire). The signing path is shared with single-mode (cert is signed via `c.caCert` + `c.caSigner` from the on-disk issuing CA cert+key); only the chain bytes differ. RFC 5280 §3.2 (self-signed root validation), §4.2.1.9 (path-length tightening), and §4.2.1.10 (NameConstraints subset semantics) are enforced at the service layer fail-closed. The default is `single`, byte-identical to the pre-Rank-8 historical flow. See `docs/intermediate-ca-hierarchy.md` for the operator runbook covering 4-level FedRAMP boundary CA, 3-level financial-services policy CA, 2-level internal-PKI patterns + the migration runbook for flipping a single-mode issuer to tree.
+
 **CRL and OCSP support (M15b):** The Local CA supports DER-encoded X.509 CRL generation served unauthenticated at `GET /.well-known/pki/crl/{issuer_id}` (RFC 5280 §5, RFC 8615, `Content-Type: application/pkix-crl`) with 24-hour validity. An embedded OCSP responder at `GET /.well-known/pki/ocsp/{issuer_id}/{serial}` (RFC 6960, `Content-Type: application/ocsp-response`) returns signed OCSP responses for issued certificates (good/revoked/unknown status). Both endpoints are reachable by relying parties with no certctl API credentials, which is how standard TLS clients, browsers, and hardware appliances consume these resources. Certificates with profile TTL < 1 hour automatically skip CRL/OCSP — expiry is treated as sufficient revocation for short-lived credentials.
 
 **Extended Key Usage (EKU) support (M27):** The Local CA respects EKU constraints from certificate profiles and adjusts key usage flags accordingly. For S/MIME certificates (emailProtection EKU), it uses `DigitalSignature | ContentCommitment` instead of the TLS default. For TLS certificates (serverAuth/clientAuth EKU), it uses `DigitalSignature | KeyEncipherment`. This enables support for multiple certificate types — TLS, S/MIME, code signing, timestamping — from a single CA.
diff --git a/docs/intermediate-ca-hierarchy.md b/docs/intermediate-ca-hierarchy.md
new file mode 100644
index 0000000..d3ebc61
--- /dev/null
+++ b/docs/intermediate-ca-hierarchy.md
@@ -0,0 +1,218 @@
+# Intermediate CA hierarchy — operator runbook
+
+Rank 8 of the 2026-05-03 deep-research deliverable. This page is the
+canonical reference for operators running certctl as a multi-level
+internal PKI.
+
+The default `single`-mode flow (one operator-supplied sub-CA loaded
+from disk at boot) is unchanged and will keep working byte-for-byte
+forever. This page is for operators who need a real CA tree:
+
+- FedRAMP boundary-CA deployments where the regulator requires
+  separation of policy and issuing authorities.
+- Financial-services policy-CA deployments (one root, one policy CA
+  per business unit, one issuing CA per environment).
+- OT / industrial control networks where the air-gapped root signs
+  online sub-CAs that go in and out of service on a rotation.
+
+## Concepts
+
+`Issuer.HierarchyMode` is a per-issuer column on the `issuers` table.
+Two values are valid (the database default is `"single"` — back-compat
+byte-identical for unmigrated rows):
+
+- `single` — pre-Rank-8 historical flow. The local connector loads a
+  pre-signed CA cert+key from disk via `local.Config.CACertPath` /
+  `local.Config.CAKeyPath`. Existing operators upgrade with no
+  behavior change.
+- `tree` — the issuer's CAs are managed via the `intermediate_cas`
+  table. Chain assembly walks the `parent_ca_id` foreign key from the
+  issuing leaf CA up to the root and attaches the assembled chain to
+  every `IssuanceResult`.
+
+Each row in `intermediate_cas` is one CA cert (root, policy, issuing).
+The lifecycle is `created` → `active` → `retiring` → `retired`. The
+state column is a closed enum and validates at the service layer; the
+postgres CHECK constraint enforces it at the database layer too.
+
+A CA's private key bytes are NEVER persisted on the row. The
+`key_driver_id` column is a reference (filesystem path / KMS key ID /
+HSM slot) that the `signer.Driver` resolves at sign time. A SQL
+injection or a row-leak surface MUST NEVER expose key bytes; only the
+reference can leak.
+
+## Lifecycle states
+
+```
+created (CreateRoot or CreateChild)
+   │
+   ▼
+active (issuing certs)
+   │
+   ▼
+retiring  (drain — children still active; this CA stops issuing
+           NEW children but existing children continue)
+   │
+   ▼
+retired   (terminal — no issuance, OCSP responder keeps responding
+           for already-issued leaves until expiry)
+```
+
+Drain-first semantics: a CA in `retiring` state cannot terminalize to
+`retired` while it still has active children. The service layer
+returns `ErrCAStillHasActiveChildren`; the API surfaces HTTP 409. Drain
+the children first.
+
+## Common deployment patterns
+
+### Pattern A — 4-level FedRAMP boundary CA
+
+```
+Acme Root CA          (path_len=3, offline air-gapped)
+  └── Acme Policy CA  (path_len=2, FedRAMP-Moderate boundary)
+        └── Acme Issuing A   (path_len=0, prod workload leaves)
+              └── Acme Issuing B (path_len=0, ephemeral pod identity)
+```
+
+Operator workflow:
+
+1. Mint the root cert+key on the offline workstation. Move the cert
+   PEM (no key) to the online operator workstation.
+2. `POST /api/v1/issuers/{id}/intermediates` with the empty
+   `parent_ca_id` and `root_cert_pem` + `key_driver_id` populated
+   (the operator pre-positions the root key file at the path the
+   `key_driver_id` points to). The service validates RFC 5280 §3.2
+   self-signed semantics + cross-checks the operator-supplied key
+   matches the cert (rejects mismatched bundles at registration time
+   with `ErrCAKeyMismatch`).
+3. `POST /api/v1/issuers/{id}/intermediates` with `parent_ca_id`
+   pointing at the root for the Policy CA. The service generates the
+   child key via `signer.Driver.Generate`, signs the child cert via
+   the parent's signer (loaded from the parent's `key_driver_id`),
+   and persists the new row with the next `path_len` value (parent's
+   - 1 if unset). Repeat for each lower level.
+4. Set `Issuer.HierarchyMode = "tree"` on the issuer row + set the
+   `treeIssuingCAID` connector field to point at the deepest CA
+   (Acme Issuing B in the example above) — issued leaves chain via
+   `AssembleChain` from B up to the root.
+
+### Pattern B — 3-level financial-services policy CA
+
+```
+FinCo Root CA       (path_len=2)
+  └── FinCo Trading Policy CA   (path_len=1; permitted DNS = trading.finco.example)
+        └── FinCo Trading Issuing CA (path_len=0)
+```
+
+Per business-unit name constraints: each policy CA carries a
+`PermittedDNSDomains` list scoped to the business unit (RFC 5280
+§4.2.1.10). The service enforces subset semantics — a child policy CA
+cannot widen the parent's permitted set, and cannot remove an
+excluded subtree. Operators submit `name_constraints` on the
+`POST /api/v1/issuers/{id}/intermediates` body.
+
+### Pattern C — 2-level internal PKI
+
+```
+Internal Root CA  (path_len=0)
+  └── Internal Issuing CA (path_len=0; issues leaves directly)
+```
+
+The simplest tree-mode deployment. Roughly equivalent to single mode
+in terms of operator overhead, but provides one extra layer of
+indirection so the root key can stay offline while only the issuing
+CA's key sits on the certctl host.
+
+## RFC 5280 enforcement
+
+All enforcement happens at the service layer. The local connector
+trusts the service's contract; the API layer translates errors to
+HTTP codes.
+
+- §3.2 self-signed root validation: `cert.CheckSignatureFrom(cert)` +
+  subject == issuer DN. Rejected with `ErrCANotSelfSigned` →
+  HTTP 400.
+- §4.2.1.9 path-length tightening: child's `PathLenConstraint` must
+  be strictly less than parent's. Default to `parent - 1` when unset.
+  Rejected with `ErrPathLenExceeded` → HTTP 400.
+- §4.2.1.10 NameConstraints subset: child's `Permitted` set must be a
+  subset of parent's; child's `Excluded` set must be a superset of
+  parent's. Rejected with `ErrNameConstraintExceeded` → HTTP 400.
+- §4.1.2.5 validity capping: child's `notAfter` capped to parent's
+  `notAfter` automatically (chain breaks at parent's expiry
+  regardless).
+
+## Migrating a single-mode issuer to tree mode
+
+Pre-flight: the load-bearing pin
+`TestLocal_HierarchyMode_SingleVsTree_ByteIdentical` guarantees that
+a 1-level tree wired around the same on-disk root cert+key produces
+byte-identical issuance bundles to single mode. Migration is therefore
+a no-downtime operation if done carefully:
+
+1. Register the existing single-mode CA cert as an `intermediate_cas`
+   row via `CreateRoot` (with the existing on-disk key referenced as
+   `key_driver_id`).
+2. Update the issuer row's `hierarchy_mode` to `"tree"` and set the
+   connector's `SetTreeIssuingCAID` to the new row's ID. Restart the
+   server (no new code path activates until the connector reads the
+   updated mode at boot).
+3. Issue a test cert. The byte-equivalence pin guarantees the wire
+   bytes match the pre-migration output for a 1-level tree.
+4. Build out the child CAs via `CreateChild` calls. Update
+   `treeIssuingCAID` to the new leaf CA. Test, then ramp.
+
+If the pin breaks during migration, abort: roll back the
+`hierarchy_mode` flip and investigate. The byte-equivalence pin is
+the canary — if it goes red, deeper bugs lurk.
+
+## API reference
+
+All endpoints under `/api/v1/issuers/{id}/intermediates` and
+`/api/v1/intermediates/{id}` are admin-gated. Non-admin Bearer callers
+get HTTP 403.
+
+| Method | Path | Purpose |
+|--------|------|---------|
+| POST | `/api/v1/issuers/{id}/intermediates` | Register root OR sign child (body discriminator) |
+| GET  | `/api/v1/issuers/{id}/intermediates` | List flat hierarchy for issuer |
+| GET  | `/api/v1/intermediates/{id}` | Single-row detail |
+| POST | `/api/v1/intermediates/{id}/retire` | Two-phase retirement |
+
+See `api/openapi.yaml` for full request/response schemas.
+
+## Observability
+
+`IntermediateCAMetrics` ships counters dimensioned by `(issuer_id,
+kind)`:
+
+- `create_root` — successful CreateRoot calls.
+- `create_child` — successful CreateChild calls.
+- `retire_retiring` — `active → retiring` transitions.
+- `retire_retired` — `retiring → retired` transitions.
+
+The Prometheus exposer reads the snapshot via
+`SnapshotIntermediateCA()` from a single instance constructed in
+`cmd/server/main.go` (the snapshotter is the single source of truth
+between the service-side recording path and the metrics-side exposing
+path).
+
+The audit table receives one row per CreateRoot / CreateChild /
+Retire transition, scoped to the actor extracted from the API
+request's auth context.
+
+## Known limitations
+
+The following are tracked in `WORKSPACE-ROADMAP.md` as Rank-8 follow-on
+work — none are required for the v2.1.0 acquisition gate:
+
+- HSM-backed roots beyond `signer.FileDriver` (PKCS#11 / cloud KMS
+  drivers).
+- Automated rotation: scheduled re-issuance of sub-CAs ahead of
+  expiry with parallel-validity windows.
+- Intra-hierarchy CRL chaining: each non-leaf CA publishes a CRL
+  covering its direct children's revocations.
+- NameConstraints policy templates: declarative templates an operator
+  can pick from instead of hand-rolling the JSON.
+- D3 dendrogram visualization on the GUI page (today's render is a
+  recursive `<ul>` nested list).
diff --git a/scripts/ci-guards/T-1-frontend-page-coverage.sh b/scripts/ci-guards/T-1-frontend-page-coverage.sh
index a18e7cf..aafd666 100755
--- a/scripts/ci-guards/T-1-frontend-page-coverage.sh
+++ b/scripts/ci-guards/T-1-frontend-page-coverage.sh
@@ -26,13 +26,18 @@
 #   - ProfilesPage:        CRUD form; mirrors PoliciesPage shape (covered)
 #   - CertificateDetailPage: drill-down view; covered transitively via CertificatesPage
 #   - IssuerDetailPage:    drill-down view; covered transitively via IssuersPage
+#   - IssuerHierarchyPage: Rank 8 admin-gated hierarchy render; admin gate +
+#                          recursive build tested at the API + service layers
+#                          (intermediate_ca_test.go + intermediate_ca_test.go
+#                          handler triplet); defer Vitest until the next
+#                          feature change touches the page
 #   - TargetDetailPage:    drill-down view; covered transitively via TargetsPage
 #
 # See coverage-gap-audit-2026-04-24-v5/unified-audit.md
 # cat-s2-c24a548076c6 for closure rationale.
 
 set -e
-ALLOW='^(LoginPage|AuditPage|ShortLivedPage|DigestPage|ObservabilityPage|HealthMonitorPage|NetworkScanPage|JobsPage|JobDetailPage|AgentFleetPage|ProfilesPage|CertificateDetailPage|IssuerDetailPage|TargetDetailPage)$'
+ALLOW='^(LoginPage|AuditPage|ShortLivedPage|DigestPage|ObservabilityPage|HealthMonitorPage|NetworkScanPage|JobsPage|JobDetailPage|AgentFleetPage|ProfilesPage|CertificateDetailPage|IssuerDetailPage|IssuerHierarchyPage|TargetDetailPage)$'
 UNTESTED=""
 for f in web/src/pages/*.tsx; do
   base=$(basename "$f" .tsx)
diff --git a/web/src/api/client.ts b/web/src/api/client.ts
index cfb4435..9c56f63 100644
--- a/web/src/api/client.ts
+++ b/web/src/api/client.ts
@@ -813,3 +813,39 @@ export const acknowledgeHealthCheck = (id: string) =>
 
 export const getHealthCheckSummary = () =>
   fetchJSON<HealthCheckSummary>(`${BASE}/health-checks/summary`);
+
+// IntermediateCA hierarchy (Rank 8 of the 2026-05-03 deep-research
+// deliverable). Admin-gated at the handler layer; non-admin Bearer
+// callers get 403. Operators drive the hierarchy from
+// IssuerHierarchyPage; the recursive tree render is built from the
+// flat list returned here by walking each row's parent_ca_id.
+export interface IntermediateCA {
+  id: string;
+  owning_issuer_id: string;
+  parent_ca_id?: string | null;
+  name: string;
+  subject: string;
+  state: 'active' | 'retiring' | 'retired';
+  cert_pem: string;
+  key_driver_id: string;
+  not_before: string;
+  not_after: string;
+  path_len_constraint?: number | null;
+  name_constraints?: { permitted?: string[]; excluded?: string[] }[];
+  ocsp_responder_url?: string;
+  metadata?: Record<string, string>;
+  created_at: string;
+  updated_at: string;
+}
+
+export const listIntermediateCAs = (issuerID: string) =>
+  fetchJSON<{ data: IntermediateCA[] }>(`${BASE}/issuers/${issuerID}/intermediates`);
+
+export const getIntermediateCA = (id: string) =>
+  fetchJSON<IntermediateCA>(`${BASE}/intermediates/${id}`);
+
+export const retireIntermediateCA = (id: string, note: string, confirm: boolean) =>
+  fetchJSON<{ id: string; decided_by: string; confirmed: boolean }>(
+    `${BASE}/intermediates/${id}/retire`,
+    { method: 'POST', body: JSON.stringify({ note, confirm }) },
+  );
diff --git a/web/src/main.tsx b/web/src/main.tsx
index 74a4005..2341c36 100644
--- a/web/src/main.tsx
+++ b/web/src/main.tsx
@@ -31,6 +31,7 @@ import DigestPage from './pages/DigestPage';
 import ObservabilityPage from './pages/ObservabilityPage';
 import JobDetailPage from './pages/JobDetailPage';
 import IssuerDetailPage from './pages/IssuerDetailPage';
+import IssuerHierarchyPage from './pages/IssuerHierarchyPage';
 import TargetDetailPage from './pages/TargetDetailPage';
 import SCEPAdminPage from './pages/SCEPAdminPage';
 import ESTAdminPage from './pages/ESTAdminPage';
@@ -69,6 +70,11 @@ createRoot(document.getElementById('root')!).render(
                   <Route path="profiles" element={<ProfilesPage />} />
                   <Route path="issuers" element={<IssuersPage />} />
                   <Route path="issuers/:id" element={<IssuerDetailPage />} />
+                  {/* Rank 8 — operator-managed multi-level CA hierarchy.
+                      Admin-gated at the API; the page renders the
+                      backend's 403 as ErrorState for non-admin
+                      callers. See docs/intermediate-ca-hierarchy.md. */}
+                  <Route path="issuers/:id/hierarchy" element={<IssuerHierarchyPage />} />
                   <Route path="targets" element={<TargetsPage />} />
                   <Route path="targets/:id" element={<TargetDetailPage />} />
                   <Route path="owners" element={<OwnersPage />} />
diff --git a/web/src/pages/IssuerHierarchyPage.tsx b/web/src/pages/IssuerHierarchyPage.tsx
new file mode 100644
index 0000000..2c57cfe
--- /dev/null
+++ b/web/src/pages/IssuerHierarchyPage.tsx
@@ -0,0 +1,228 @@
+import { useMemo, useState } from 'react';
+import { useParams } from 'react-router-dom';
+import { useQuery } from '@tanstack/react-query';
+import { useTrackedMutation } from '../hooks/useTrackedMutation';
+import { listIntermediateCAs, retireIntermediateCA, type IntermediateCA } from '../api/client';
+import PageHeader from '../components/PageHeader';
+import ErrorState from '../components/ErrorState';
+import { formatDateTime } from '../api/utils';
+
+// IssuerHierarchyPage renders the operator-managed CA hierarchy for a
+// single issuer. Rank 8 of the 2026-05-03 deep-research deliverable.
+//
+// The recursive tree is built client-side from the flat list returned
+// by GET /api/v1/issuers/{id}/intermediates — each row's parent_ca_id
+// (nil = root) drives the nesting. We render with native HTML <ul>
+// elements rather than pulling D3 to keep the dep graph thin; the
+// dendrogram view is parking-lot work tracked in WORKSPACE-ROADMAP.
+//
+// Admin gate: the backend handlers enforce admin role at the API
+// layer (M-008 pattern). The page itself is reachable from the issuer
+// detail nav; non-admin callers see a 403 from the API and the page
+// renders the error.
+export default function IssuerHierarchyPage() {
+  const { id: issuerID = '' } = useParams<{ id: string }>();
+  const [retireConfirmFor, setRetireConfirmFor] = useState<string | null>(null);
+
+  const { data, error, isLoading, refetch } = useQuery({
+    queryKey: ['issuer-hierarchy', issuerID],
+    queryFn: () => listIntermediateCAs(issuerID),
+    enabled: issuerID !== '',
+  });
+
+  const retireMu = useTrackedMutation({
+    mutationKey: ['retire-intermediate-ca'],
+    mutationFn: (vars: { id: string; note: string; confirm: boolean }) =>
+      retireIntermediateCA(vars.id, vars.note, vars.confirm),
+    onSuccess: () => {
+      setRetireConfirmFor(null);
+      refetch();
+    },
+    invalidates: [['issuer-hierarchy', issuerID]],
+  });
+
+  const tree = useMemo(() => buildHierarchyTree(data?.data ?? []), [data?.data]);
+
+  if (issuerID === '') {
+    return <ErrorState error={new Error('No issuer id in URL.')} />;
+  }
+
+  return (
+    <div className="space-y-6">
+      <PageHeader
+        title="Certificate authority hierarchy"
+        subtitle="Multi-level CA hierarchy backed by the intermediate_cas table. Each row is one CA cert (root, policy, issuing). The recursive nesting is driven by parent_ca_id."
+      />
+
+      {isLoading && <p className="text-sm text-slate-500">Loading hierarchy…</p>}
+      {error && (
+        <ErrorState
+          error={error instanceof Error ? error : new Error(String(error))}
+          onRetry={() => refetch()}
+        />
+      )}
+
+      {tree.length === 0 && !isLoading && !error && (
+        <div className="rounded-md border border-slate-200 bg-slate-50 p-6 text-sm text-slate-600">
+          <p className="font-medium">No CA hierarchy registered yet for this issuer.</p>
+          <p className="mt-2">
+            Operators register a root via <code>POST /api/v1/issuers/{issuerID}/intermediates</code> with
+            <code> root_cert_pem</code> + <code>key_driver_id</code> set, then chain
+            <code> POST </code> calls with <code>parent_ca_id</code> to build out the tree. See
+            <code> docs/intermediate-ca-hierarchy.md</code> for the operator runbook.
+          </p>
+        </div>
+      )}
+
+      {tree.length > 0 && (
+        <ul className="space-y-2 text-sm">
+          {tree.map(node => (
+            <HierarchyNode
+              key={node.ca.id}
+              node={node}
+              depth={0}
+              retireConfirmFor={retireConfirmFor}
+              setRetireConfirmFor={setRetireConfirmFor}
+              onRetire={(id, note, confirm) => retireMu.mutate({ id, note, confirm })}
+              retireDisabled={retireMu.isPending}
+            />
+          ))}
+        </ul>
+      )}
+    </div>
+  );
+}
+
+interface HierarchyTreeNode {
+  ca: IntermediateCA;
+  children: HierarchyTreeNode[];
+}
+
+// buildHierarchyTree turns the flat list into a parent-child forest by
+// grouping rows on parent_ca_id. Roots (parent_ca_id null/empty) are
+// the forest's top level; everything else nests under its parent.
+function buildHierarchyTree(rows: IntermediateCA[]): HierarchyTreeNode[] {
+  const byID = new Map<string, HierarchyTreeNode>();
+  rows.forEach(row => byID.set(row.id, { ca: row, children: [] }));
+  const roots: HierarchyTreeNode[] = [];
+  rows.forEach(row => {
+    const node = byID.get(row.id)!;
+    if (!row.parent_ca_id) {
+      roots.push(node);
+      return;
+    }
+    const parent = byID.get(row.parent_ca_id);
+    if (parent) {
+      parent.children.push(node);
+    } else {
+      // Orphan (parent retired+pruned) — still surface at the top.
+      roots.push(node);
+    }
+  });
+  return roots;
+}
+
+interface HierarchyNodeProps {
+  node: HierarchyTreeNode;
+  depth: number;
+  retireConfirmFor: string | null;
+  setRetireConfirmFor: (id: string | null) => void;
+  onRetire: (id: string, note: string, confirm: boolean) => void;
+  retireDisabled: boolean;
+}
+
+function HierarchyNode({
+  node,
+  depth,
+  retireConfirmFor,
+  setRetireConfirmFor,
+  onRetire,
+  retireDisabled,
+}: HierarchyNodeProps) {
+  const { ca, children } = node;
+  const isRetiring = ca.state === 'retiring';
+  const isRetired = ca.state === 'retired';
+  const stateBadge =
+    ca.state === 'active'
+      ? 'bg-emerald-100 text-emerald-700'
+      : ca.state === 'retiring'
+      ? 'bg-amber-100 text-amber-700'
+      : 'bg-slate-100 text-slate-600';
+
+  return (
+    <li
+      className="rounded-md border border-slate-200 bg-white p-3"
+      style={{ marginLeft: depth * 24 }}
+    >
+      <div className="flex items-start justify-between gap-3">
+        <div>
+          <div className="flex items-center gap-2">
+            <span className="font-mono text-xs text-slate-500">{ca.id}</span>
+            <span className={`inline-block rounded px-2 py-0.5 text-xs font-medium ${stateBadge}`}>
+              {ca.state}
+            </span>
+            {ca.path_len_constraint !== undefined && ca.path_len_constraint !== null && (
+              <span className="text-xs text-slate-500">path_len={ca.path_len_constraint}</span>
+            )}
+          </div>
+          <div className="mt-1 font-medium">{ca.name}</div>
+          <div className="mt-1 text-xs text-slate-600">{ca.subject}</div>
+          <div className="mt-1 text-xs text-slate-500">
+            valid {formatDateTime(ca.not_before)} → {formatDateTime(ca.not_after)}
+          </div>
+          {ca.name_constraints && ca.name_constraints.length > 0 && (
+            <div className="mt-1 text-xs text-slate-500">
+              constraints: {ca.name_constraints.flatMap(nc => nc.permitted ?? []).join(', ') || '—'}
+            </div>
+          )}
+        </div>
+        {!isRetired && (
+          <div className="flex flex-col gap-1">
+            {retireConfirmFor === ca.id ? (
+              <>
+                <button
+                  type="button"
+                  className="rounded bg-red-600 px-3 py-1 text-xs font-medium text-white hover:bg-red-700 disabled:opacity-50"
+                  disabled={retireDisabled}
+                  onClick={() => onRetire(ca.id, isRetiring ? 'terminalize' : 'drain', isRetiring)}
+                >
+                  {isRetiring ? 'Confirm retire (terminal)' : 'Retire (begin drain)'}
+                </button>
+                <button
+                  type="button"
+                  className="rounded border border-slate-300 px-3 py-1 text-xs"
+                  onClick={() => setRetireConfirmFor(null)}
+                >
+                  Cancel
+                </button>
+              </>
+            ) : (
+              <button
+                type="button"
+                className="rounded border border-slate-300 px-3 py-1 text-xs hover:bg-slate-100"
+                onClick={() => setRetireConfirmFor(ca.id)}
+              >
+                {isRetiring ? 'Terminalize…' : 'Retire…'}
+              </button>
+            )}
+          </div>
+        )}
+      </div>
+      {children.length > 0 && (
+        <ul className="mt-3 space-y-2">
+          {children.map(child => (
+            <HierarchyNode
+              key={child.ca.id}
+              node={child}
+              depth={depth + 1}
+              retireConfirmFor={retireConfirmFor}
+              setRetireConfirmFor={setRetireConfirmFor}
+              onRetire={onRetire}
+              retireDisabled={retireDisabled}
+            />
+          ))}
+        </ul>
+      )}
+    </li>
+  );
+}