Harden SSH Admission And Credential Input

docs/command_reference.md

@@ -32,7 +32,7 @@ Browser `web` allows only status/stop/exact forced certificate rotation; `wifi`/
 | `user key clear <username> --force` | Delete all public keys for an account. |
 | `user recover --force` | When normal user-database initialization failed, explicitly replace only its blob with an empty database; UART0-only, refuses a healthy database. |
 
-Usernames must match `[a-z][a-z0-9_-]{0,15}`. Passwords contain 12–64 printable ASCII characters. The fixed database supports eight users and three SSH keys per user; initial key types are `ssh-ed25519` and `ecdsa-sha2-nistp256`. A key may be assigned to multiple accounts but cannot be duplicated within one account. Password verifiers, salts, raw key blobs, and passwords are absent from ordinary status output. `Ctrl-C` cancels a password or key prompt, and generated passwords are shown once.
+Usernames must match `[a-z][a-z0-9_-]{0,15}`. Passwords contain 12–64 printable ASCII characters. Hidden console prompts reject overflow or unsupported bytes rather than accepting a truncated/normalized prefix, even if later editing reduces the length; submit or cancel and start again. CR/LF submits, Backspace/Delete edits, and Ctrl-C cancels. The fixed database supports eight users and three SSH keys per user; initial key types are `ssh-ed25519` and `ecdsa-sha2-nistp256`. A key may be assigned to multiple accounts but cannot be duplicated within one account. Password verifiers, salts, raw key blobs, and passwords are absent from ordinary status output. `Ctrl-C` cancels a password or key prompt, and generated passwords are shown once.
 
 Missing `user_db/database` storage is committed empty. On UART0 run `user add <username> admin`, optionally with `--generate`, to create the first administrator. There is no bootstrap command, imported shared credential, or synchronization with HTTPS material. Existing valid v1 user databases load unchanged, including previously migrated role-`user` accounts; no account is silently promoted.
 
@@ -157,6 +157,10 @@ HTTPS listens on port 443 only. Authenticate with any current user-database user
 
 SSH listens on port 22 and accepts user-database passwords plus stored `ssh-ed25519` and `ecdsa-sha2-nistp256` public keys. wolfSSH verifies key possession after the database authorizes the username/key pair; unsigned key probes do not complete authentication. A `user` receives the broker-backed UART1 serial stream. An `admin` receives the administration shell instead, does not become a broker client, and cannot acquire a UART1 writer lease.
 
+SSH admission uses global boot-lifetime token buckets: handshakes and password/signed-key requests each allow a burst of six and refill one token per ten seconds; unsigned-key probes allow twelve and refill one per five seconds. The existing three-counted-attempt failure closure remains per connection. Reconnect, `ssh stop`/`ssh start`, host-key rotation and `ssh clear-counters` do not replenish these budgets. Rate denial closes the authenticating connection, not an established stream. Restrict hostile traffic and allow natural refill; repeatedly reconnecting consumes shared capacity and can prevent other users from logging in.
+
+`ssh counters` separates handshake/verification/probe admissions and rate rejections, attempt-limit closures, backend errors and rejected methods. Admitted work is not necessarily successful or completed; probes/rate denials are not completed `auth-attempts`. These counters expose no submitted credentials and clearing them does not change enforcement. Keyboard-interactive is explicitly rejected, not merely omitted from the advertised list. See [policy and validation](security_hardening.md#9b-ssh-admission-and-credential-handling).
+
 UART0 and admin SSH submit to one bounded queue, and one dispatcher task is the sole caller of `esp_console_run()`. Consequently, SSH commands execute the canonical UART0 handlers and produce the same status and mutation behavior rather than using a second command implementation. Remote output is routed into the authenticated session's bounded output ring; only the SSH transport task accesses wolfSSH.
 
 UART0 and admin SSH use shared whole-line Tab completion. A unique/common prefix expands inline; a Tab that cannot extend an ambiguous prefix prints the matching candidates and redraws the unchanged input line instead of cycling candidates. Admin SSH additionally supports four-entry per-session command history with Up/Down, inline cursor editing with Left/Right, Home/End (including Pos1/Ende terminal sequences), Backspace/Delete, Ctrl-C, and visible or no-echo interactive prompts. Its history is RAM-only, private to the session, and wiped on disconnect. Ping callbacks enqueue bounded typed results so all formatting remains on the dispatcher task.