Add SSH Access: enable sshd and import keys from GitHub/Launchpad (ssh-import-id)

Offered during first-time install and under Addons -> Remote Access. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_013wi3ZQveYdjfcrEsyazq32
Revert Tailscale/Netbird SSH toggles (misread request)
2026-11-05 21:41:18 +00:00 · 2026-11-05 21:40:49 +00:00
2 changed files with 148 additions and 110 deletions
@@ -350,7 +350,7 @@ provision_configure_kiosk_settings() {
    fi

    if [[ "${KIOSK_UNATTENDED:-0}" != "1" ]]; then
-        remote_ssh_first_time_setup
+        ssh_first_time_setup
    fi

    echo
@@ -1,7 +1,7 @@
 #!/bin/bash
 ################################################################################
 # menus/addon_remote_access.sh - "Remote Access" addon (VNC, WireGuard,
-# Tailscale, Netbird).
+# Tailscale, Netbird) plus SSH Access (GitHub/Launchpad key import).
 #
 # Third Addon migrated, and the biggest so far in scope (4 sub-areas).
 # All four genuinely mutate real system state at fixed paths this project
@@ -31,6 +31,7 @@ VNC_APT_PACKAGES=(x11vnc)
 WIREGUARD_APT_PACKAGES=(wireguard wireguard-tools)

 remote_access_status() {
+    echo "SSH:       $(ssh_status_line)"
    echo "VNC:       $(is_service_active x11vnc && echo "running" || echo "not installed")"
    echo "WireGuard: $(wireguard_connected && echo "connected" || (command -v wg &>/dev/null && echo "installed, not connected" || echo "not installed"))"
    echo "Tailscale: $(command -v tailscale &>/dev/null && echo "installed" || echo "not installed")"
@@ -38,8 +39,8 @@ remote_access_status() {
 }

 remote_access_menu_builder() {
-    MENU_LABELS=("VNC Remote Desktop" "WireGuard VPN" "Tailscale VPN" "Netbird VPN")
-    MENU_HANDLERS=(vnc_menu wireguard_menu tailscale_menu netbird_menu)
+    MENU_LABELS=("SSH Access (GitHub/Launchpad keys)" "VNC Remote Desktop" "WireGuard VPN" "Tailscale VPN" "Netbird VPN")
+    MENU_HANDLERS=(ssh_menu vnc_menu wireguard_menu tailscale_menu netbird_menu)
 }

 remote_access_menu() {
@@ -264,7 +265,6 @@ tailscale_status() {

    if [[ "$(tailscale_backend_state)" == "Running" ]]; then
        echo "Tailscale: connected"
-        echo "  SSH:      $(tailscale_ssh_enabled && echo "enabled" || echo "disabled")"
        echo "  Hostname: $(tailscale status --json 2>/dev/null | jq -r '.Self.HostName // "unknown"')"
        echo "  IP:       $(tailscale ip -4 2>/dev/null)"
    else
@@ -272,40 +272,10 @@ tailscale_status() {
    fi
 }

-# Tailscale SSH: tailscaled itself answers SSH on this machine's tailnet
-# address, authenticated by tailnet identity - no keys to manage. Which
-# users may log in as whom is set by the tailnet's ACL "ssh" rules in the
-# Tailscale admin console (https://login.tailscale.com/admin/acls).
-tailscale_ssh_enabled() {
-    [[ "$(tailscale debug prefs 2>/dev/null | jq -r '.RunSSH // false' 2>/dev/null)" == "true" ]]
-}
-
-# Echoes "--ssh" when the user wants Tailscale SSH, nothing otherwise.
-tailscale_ask_ssh_flag() {
-    if ask_yes_no "Enable Tailscale SSH (log in over the tailnet, no SSH keys)?" "y" >&2; then
-        echo "--ssh"
-    fi
-}
-
-action_tailscale_toggle_ssh() {
-    echo
-    if [[ "$(tailscale_backend_state)" != "Running" ]]; then
-        log_error "Connect Tailscale first (Connect, above)"
-        return 1
-    fi
-    if tailscale_ssh_enabled; then
-        ask_yes_no "Tailscale SSH is ENABLED. Disable it?" "n" || { echo "Cancelled"; return; }
-        sudo tailscale set --ssh=false && log_success "Tailscale SSH disabled"
-    else
-        sudo tailscale set --ssh=true && log_success "Tailscale SSH enabled"
-        echo "Allow it in your tailnet ACL (\"ssh\" rules): https://login.tailscale.com/admin/acls"
-    fi
-}
-
 tailscale_menu_builder() {
    if command -v tailscale &>/dev/null; then
-        MENU_LABELS=("Connect (interactive)" "Connect with auth key" "Enable/disable Tailscale SSH" "Show status" "Uninstall")
-        MENU_HANDLERS=(action_tailscale_connect_interactive action_tailscale_connect_authkey action_tailscale_toggle_ssh action_tailscale_show_status action_tailscale_uninstall)
+        MENU_LABELS=("Connect (interactive)" "Connect with auth key" "Show status" "Uninstall")
+        MENU_HANDLERS=(action_tailscale_connect_interactive action_tailscale_connect_authkey action_tailscale_show_status action_tailscale_uninstall)
    else
        MENU_LABELS=("Install Tailscale")
        MENU_HANDLERS=(action_tailscale_install)
@@ -316,13 +286,9 @@ tailscale_menu() {
    run_menu "TAILSCALE VPN" tailscale_menu_builder tailscale_status
 }

-# $1 = "noconfirm" skips the "Install?" question (first-time install
-# has already asked).
 action_tailscale_install() {
    echo
-    if [[ "${1:-}" != "noconfirm" ]]; then
-        ask_yes_no "Install Tailscale?" "n" || { echo "Cancelled"; return; }
-    fi
+    ask_yes_no "Install Tailscale?" "n" || { echo "Cancelled"; return; }

    if ! curl -fsSL https://tailscale.com/install.sh | sh; then
        log_error "Tailscale installation failed"
@@ -345,10 +311,7 @@ action_tailscale_install() {

 action_tailscale_connect_interactive() {
    echo
-    local ssh_flag
-    ssh_flag=$(tailscale_ask_ssh_flag)
-    # shellcheck disable=SC2086 # ssh_flag is empty or exactly "--ssh"
-    if sudo tailscale up $ssh_flag; then
+    if sudo tailscale up; then
        log_success "Tailscale connected"
    else
        log_error "Tailscale connection failed"
@@ -365,10 +328,7 @@ action_tailscale_connect_authkey() {
        return
    fi

-    local ssh_flag
-    ssh_flag=$(tailscale_ask_ssh_flag)
-    # shellcheck disable=SC2086 # ssh_flag is empty or exactly "--ssh"
-    if sudo tailscale up --authkey="$authkey" $ssh_flag; then
+    if sudo tailscale up --authkey="$authkey"; then
        log_success "Tailscale connected"
    else
        log_error "Tailscale connection failed"
@@ -409,48 +369,16 @@ netbird_status() {

    if netbird_connected; then
        echo "Netbird: connected"
-        echo "  SSH:      $(netbird_ssh_enabled && echo "enabled" || echo "disabled")"
        netbird status 2>/dev/null | grep -E "NetBird IP:|Public key:" | sed 's/^/  /' || true
    else
        echo "Netbird: installed, not connected"
    fi
 }

-# Netbird's built-in SSH server listens on port 22022 on the Netbird
-# interface (wt0). ufw's default-deny-incoming (lib/provision.sh) would
-# block it, so open that port on wt0 only.
-netbird_ssh_enabled() {
-    netbird status 2>/dev/null | grep -qiE '^SSH Server:.*(enabled|true)' ||
-        sudo -n grep -qE '"ServerSSHAllowed": *true' /var/lib/netbird/default.json 2>/dev/null
-}
-
-netbird_open_ssh_firewall() {
-    if command -v ufw &>/dev/null && sudo ufw status 2>/dev/null | grep -q "Status: active"; then
-        sudo ufw allow in on wt0 to any port 22022 proto tcp >/dev/null &&
-            log_info "Firewall: allowed Netbird SSH (22022) on wt0 only"
-    fi
-}
-
-action_netbird_toggle_ssh() {
-    echo
-    if ! netbird_connected; then
-        log_error "Connect Netbird first (Connect, above)"
-        return 1
-    fi
-    if netbird_ssh_enabled; then
-        ask_yes_no "Netbird SSH is ENABLED. Disable it?" "n" || { echo "Cancelled"; return; }
-        sudo netbird up --allow-server-ssh=false && log_success "Netbird SSH disabled"
-    else
-        sudo netbird up --allow-server-ssh && log_success "Netbird SSH enabled" &&
-            netbird_open_ssh_firewall
-        echo "Connect from another Netbird peer: ssh <user>@<netbird-ip> (port 22022 if your client needs it)"
-    fi
-}
-
 netbird_menu_builder() {
    if command -v netbird &>/dev/null; then
-        MENU_LABELS=("Connect with setup key" "Enable/disable Netbird SSH" "Show status" "Uninstall")
-        MENU_HANDLERS=(action_netbird_connect action_netbird_toggle_ssh action_netbird_show_status action_netbird_uninstall)
+        MENU_LABELS=("Connect with setup key" "Show status" "Uninstall")
+        MENU_HANDLERS=(action_netbird_connect action_netbird_show_status action_netbird_uninstall)
    else
        MENU_LABELS=("Install Netbird")
        MENU_HANDLERS=(action_netbird_install)
@@ -461,13 +389,9 @@ netbird_menu() {
    run_menu "NETBIRD VPN" netbird_menu_builder netbird_status
 }

-# $1 = "noconfirm" skips the "Install?" question (first-time install
-# has already asked).
 action_netbird_install() {
    echo
-    if [[ "${1:-}" != "noconfirm" ]]; then
-        ask_yes_no "Install Netbird?" "n" || { echo "Cancelled"; return; }
-    fi
+    ask_yes_no "Install Netbird?" "n" || { echo "Cancelled"; return; }

    if ! curl -fsSL https://pkgs.netbird.io/install.sh | sh; then
        log_error "Netbird installation failed"
@@ -491,13 +415,8 @@ action_netbird_connect() {
        return
    fi

-    local ssh_flag=()
-    if ask_yes_no "Enable Netbird SSH (log in over the Netbird network)?" "y"; then
-        ssh_flag=(--allow-server-ssh)
-    fi
-    if sudo netbird up --setup-key "$setup_key" "${ssh_flag[@]}"; then
+    if sudo netbird up --setup-key "$setup_key" --allow-server-ssh; then
        log_success "Netbird connected"
-        if [[ ${#ssh_flag[@]} -gt 0 ]]; then netbird_open_ssh_firewall; fi
    else
        log_error "Netbird connection failed"
    fi
@@ -522,22 +441,141 @@ netbird_do_uninstall() {
 }

 ################################################################################
-# First-time install hook (called from lib/provision.sh): offer to set up
-# one of the two mesh-VPN providers with SSH enabled, so the kiosk is
-# reachable remotely right after install.
+# SSH Access - openssh-server plus public keys imported from GitHub or
+# Launchpad with ssh-import-id (the same "Import SSH identity" choice
+# Ubuntu's own installer offers). Keys go to the admin user running this
+# menu (~/.ssh/authorized_keys), never to the restricted `kiosk` user.
+# The key sets published by those services are fetched over HTTPS and
+# are public data, so no secret is handled here.
 ################################################################################
-remote_ssh_first_time_setup() {
+
+SSH_KEYS_ONLY_CONF="${SSHD_CONFIG_DIR:-/etc/ssh/sshd_config.d}/10-kiosk-keys-only.conf"
+SSH_AUTH_KEYS="${SSH_AUTH_KEYS:-$HOME/.ssh/authorized_keys}"
+
+ssh_key_count() {
+    [[ -f "$SSH_AUTH_KEYS" ]] && grep -cE '^(ssh-|ecdsa-|sk-)' "$SSH_AUTH_KEYS" || echo 0
+}
+
+ssh_status_line() {
+    local state="not installed"
+    if is_service_active ssh || is_service_active sshd; then
+        state="running"
+    elif dpkg -s openssh-server &>/dev/null; then
+        state="installed, not running"
+    fi
+    local pw="password login on"
+    [[ -f "$SSH_KEYS_ONLY_CONF" ]] && pw="keys only"
+    echo "$state, $(ssh_key_count) key(s), $pw"
+}
+
+ssh_status() {
+    echo "SSH: $(ssh_status_line)"
+    echo "  Keys go to: $SSH_AUTH_KEYS"
+}
+
+ssh_menu_builder() {
+    MENU_LABELS=("Enable SSH server" "Import keys from GitHub" "Import keys from Launchpad" "List authorized keys" "Require keys (disable password login)" "Allow password login again")
+    MENU_HANDLERS=(action_ssh_enable action_ssh_import_github action_ssh_import_launchpad action_ssh_list_keys action_ssh_keys_only action_ssh_allow_passwords)
+}
+
+ssh_menu() {
+    run_menu "SSH ACCESS" ssh_menu_builder ssh_status
+}
+
+action_ssh_enable() {
    echo
-    echo "Remote SSH access over a mesh VPN lets you manage the kiosk from"
-    echo "anywhere with no port forwarding:"
-    echo "  1. Tailscale (with Tailscale SSH)"
-    echo "  2. Netbird   (with Netbird SSH)"
-    echo "  3. Skip (configure later: Addons -> Remote Access)"
+    sudo apt install -y openssh-server ssh-import-id || { log_error "Could not install openssh-server"; return 1; }
+    sudo systemctl enable --now ssh || { log_error "Could not start the SSH server"; return 1; }
+    # provision_configure_firewall already allows ssh; harmless if repeated.
+    if command -v ufw &>/dev/null && sudo ufw status 2>/dev/null | grep -q "Status: active"; then
+        sudo ufw allow ssh >/dev/null
+    fi
+    log_success "SSH server enabled"
+}
+
+# $1 = "gh" or "lp", $2 = label for messages.
+ssh_import_from() {
+    local prefix="$1" label="$2" user
+    echo
+    if ! command -v ssh-import-id &>/dev/null; then
+        sudo apt install -y ssh-import-id || { log_error "Could not install ssh-import-id"; return 1; }
+    fi
+    read -r -p "$label username (blank to cancel): " user
+    [[ -z "$user" ]] && { echo "Cancelled"; return; }
+    if [[ ! "$user" =~ ^[A-Za-z0-9][A-Za-z0-9._-]*$ ]]; then
+        log_error "That doesn't look like a valid $label username"
+        return 1
+    fi
+    if ssh-import-id "${prefix}:${user}"; then
+        log_success "Imported $label keys for $user ($(ssh_key_count) key(s) now authorized)"
+    else
+        log_error "Import failed - check the username and that this machine can reach $label"
+        return 1
+    fi
+}
+
+action_ssh_import_github()    { ssh_import_from gh "GitHub"; }
+action_ssh_import_launchpad() { ssh_import_from lp "Launchpad"; }
+
+action_ssh_list_keys() {
+    echo
+    if [[ "$(ssh_key_count)" == "0" ]]; then
+        echo "No authorized keys for $USER yet."
+    else
+        ssh-keygen -lf "$SSH_AUTH_KEYS"
+    fi
+}
+
+action_ssh_keys_only() {
+    echo
+    if [[ "$(ssh_key_count)" == "0" ]]; then
+        log_error "No authorized keys yet - import some first, or you'd lock yourself out"
+        return 1
+    fi
+    echo "Log in from another machine with a key BEFORE doing this; password"
+    echo "logins over SSH will stop working."
+    ask_yes_no "Disable SSH password login?" "n" || { echo "Cancelled"; return; }
+    printf 'PasswordAuthentication no\nKbdInteractiveAuthentication no\n' |
+        sudo install -D -m 644 /dev/stdin "$SSH_KEYS_ONLY_CONF"
+    if sudo sshd -t && sudo systemctl reload ssh; then
+        log_success "SSH now requires a key"
+    else
+        sudo rm -f "$SSH_KEYS_ONLY_CONF"
+        log_error "sshd rejected the config - reverted"
+        return 1
+    fi
+}
+
+action_ssh_allow_passwords() {
+    echo
+    sudo rm -f "$SSH_KEYS_ONLY_CONF"
+    sudo systemctl reload ssh 2>/dev/null || true
+    log_success "SSH password login allowed again"
+}
+
+# First-time install hook (called from lib/provision.sh).
+ssh_first_time_setup() {
+    echo
+    echo "SSH lets you manage the kiosk remotely. Ubuntu can import your"
+    echo "public keys from GitHub or Launchpad so you can log in with no password."
+    ask_yes_no "Enable SSH and import keys now?" "y" || { log_info "Configure later: Addons -> Remote Access -> SSH Access"; return; }
+    action_ssh_enable || return 0
    local choice
-    choice=$(ask_integer "Choose" "3" 1 3)
-    case "$choice" in
-        1) action_tailscale_install noconfirm ;;
-        2) action_netbird_install noconfirm ;;
-        *) log_info "Configure later: Addons -> Remote Access" ;;
-    esac
+    while true; do
+        echo
+        echo "Import keys from:"
+        echo "  1. GitHub"
+        echo "  2. Launchpad"
+        echo "  3. Done"
+        choice=$(ask_integer "Choose" "3" 1 3)
+        case "$choice" in
+            1) action_ssh_import_github || true ;;
+            2) action_ssh_import_launchpad || true ;;
+            *) break ;;
+        esac
+    done
+    if [[ "$(ssh_key_count)" != "0" ]]; then
+        echo "Tip: Remote Access -> SSH Access can switch SSH to key-only login"
+        echo "once you've confirmed a key works."
+    fi
 }