Add Serialized SSH Administrative Console

docs/roadmap.md

@@ -38,7 +38,7 @@ These constraints apply across all phases:
 | 5B | Offline xterm.js WebSocket serial terminal | **Complete** |
 | 6 | Authenticated SSH serial transport | **Complete** |
 | 7 | Local display and button interface | **Complete** |
-| 8 | Role-based users and administrative access | **In progress (8A–8B complete; 8C–8E planned)** |
+| 8 | Role-based users and administrative access | **In progress (8A–8B complete; 8C validation pending; 8D–8E planned)** |
 | 9 | Security and production hardening | **Planned** |
 | 10 | Authenticated, rollback-capable OTA | **Planned** |
 | 11 | BLE serial transport and provisioning evaluation | **Planned** |
@@ -179,7 +179,7 @@ The software-crypto build no longer reproduces the HTTPD watchdog stall. This va
 
 ## Current and planned phases
 
-The order below is the current plan. Phase 7, Phase 8A, and Phase 8B are complete; later work remains planned or under evaluation. Detailed requirements should be finalized at the start of each phase, and optional features must not weaken the completed serial and recovery paths.
+The order below is the current plan. Phase 7, Phase 8A, and Phase 8B are complete; Phase 8C is implemented and awaiting target-hardware validation; later work remains planned or under evaluation. Detailed requirements should be finalized at the start of each phase, and optional features must not weaken the completed serial and recovery paths.
 
 ### Phase 7 — Local display and buttons
 
@@ -263,10 +263,14 @@ Implementation sequence:
    - **Completed SSH-key validation:** Ed25519 and ECDSA P-256 public-key login work for both roles, including normal unsigned probe followed by signed proof-of-possession. A public key may be assigned to multiple accounts but cannot be duplicated within one account; the SSH username selects the account principal. Unsupported or incorrect credentials remain rejected without granting a broker client.
    - **Completed ticket and revocation validation:** WebSocket tickets are account-bound, one-time, and expire as intended. Password, role, key, delete, and username-recreation mutations promptly revoke only the affected user's tickets and active network sessions, release any affected writer lease, and leave unrelated users connected.
    - **Completed recovery and concurrency validation:** The database-unavailable path fails closed and retains UART0 recovery. Concurrent USB CDC, WebSocket, SSH, UART1, and UART0 operation preserves normal serial writer/observer behavior. `web credentials rotate --force` remains recovery-only after bootstrap. `web reset --force` restarts HTTPS with a replacement certificate without revoking unrelated SSH sessions; browsers correctly require a fresh TLS certificate acceptance before reconnecting.
-3. **Phase 8C — SSH administrative shell — Planned**
-   - Route authenticated `admin` SSH shell sessions to the same registered administrative command set as UART0, without creating a broker client. Normal users continue to receive the existing broker-backed serial stream.
-   - Serialize command parsing safely because ESP-IDF console internals are process-global. Use bounded per-session input/output queues and a separate command worker; only the SSH owner task may call wolfSSH APIs.
+3. **Phase 8C — SSH administrative shell — Implemented; validation pending**
+   - Authenticated `admin` SSH shell sessions route to a bounded administration worker and never create a broker client or acquire a serial writer lease. Normal `user` sessions retain the existing broker-backed serial stream.
+   - UART0 and admin SSH now submit complete lines to one fixed-length request queue. A single dispatcher task is the sole caller of ESP-IDF's non-reentrant `esp_console_run()` and therefore executes the same registered command handlers for both entry routes. The former separately implemented reduced SSH command dispatcher has been removed.
+   - The worker uses fixed per-session command/input and output buffers. Queue records contain copied secret-free principals and generation-tagged session tokens; late work is discarded after disconnect, slot reuse, role change, password/key mutation, or deletion. Task-local standard streams route canonical handler output into the applicable bounded SSH ring, and only the SSH owner task calls wolfSSH APIs.
+   - Transport policy, rather than duplicate command implementations, restricts operations requiring physical recovery authority, raw UART0 prompts, asynchronous callback output, or mutation of the active SSH service. Remote-safe generated account/password operations and non-interactive Ed25519/ECDSA key import use the canonical `user` handler. Bootstrap, database recovery, manual password/key prompts, recovery credentials, Wi-Fi secrets, reboot, ping, and SSH identity/service mutation remain physical-console-only.
+   - `ssh sessions` and `ssh counters` identify broker versus admin-console routes, worker command state, queued admin output, admission failures, and input backpressure. Admin sessions are checked for a current `admin` principal before command execution and during the active-session reconciliation.
    - Keep SFTP, SCP, `exec`, forwarding, subsystems, and unauthenticated shells disabled.
+   - Pending target-hardware validation: route separation from the broker, administrative command input/editing/output/backpressure, generated user/password/key management including the longest ECDSA P-256 import, physical-only command rejection, targeted self/other-user revocation during queued work, UART0/SSH administration serialization, and concurrent USB/WebSocket/user-SSH/admin-SSH operation.
 4. **Phase 8D — Web user administration — Planned**
    - Add an admin-only user-management interface and typed, bounded APIs for account CRUD, roles, password generation/change, SSH-key management, and revocation. Never expose a generic HTTP endpoint that executes arbitrary CLI text.
    - Hide administrative navigation and controls for normal users, and enforce every authorization decision server-side so hidden UI is not treated as a security boundary.