fix: remove terminal module and implement concurrent log stream limiting

.gitea/workflows/build.yaml

@@ -10,13 +10,22 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          fetch-depth: 0  # svu needs full history + tags
+          fetch-depth: 0
 
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.26'
+          go-version: "1.26"
           cache: false
 
+      - name: Install PAM headers (needed by go test)
+        run: sudo apt-get update && sudo apt-get install -y libpam0g-dev
+
+      - name: Run tests
+        run: |
+          set -ex
+          go vet ./...
+          go test ./...
+
       - name: Install svu
         timeout-minutes: 3
         run: |
@@ -87,6 +96,19 @@ jobs:
             go build -ldflags="$LDFLAGS" -o dist/nadir-$VERSION-linux-arm64 ./cmd/server
           upx --best --lzma dist/nadir-$VERSION-linux-amd64 dist/nadir-$VERSION-linux-arm64
 
+      - name: Sign checksums
+        if: steps.ver.outputs.release == 'true'
+        env:
+          MINISIGN_SECRET_KEY: ${{ secrets.MINISIGN_SECRET_KEY }}
+          MINISIGN_PASSWORD: ${{ secrets.MINISIGN_PASSWORD }}
+        run: |
+          set -ex
+          cd dist
+          sha256sum nadir-* > sha256sums.txt
+          cat sha256sums.txt
+          go run ../tools/sign-checksums sha256sums.txt
+          ls -la sha256sums.txt sha256sums.txt.minisig
+
       - name: Tag and release
         if: steps.ver.outputs.release == 'true'
         env:

.gitignore

@@ -11,4 +11,6 @@ config.yml
 # Editor
 *.swp
 
-CLAUDE.md
+CLAUDE.md
+
+minisign.key

README.md

@@ -31,7 +31,6 @@ API and declares its own permission vocabulary.
   and upgrade - streamed live over SSE. Auto-detects `dnf`, `apt`, or `pacman`.
 - **Networking** - List network interfaces, routing tables, and DNS settings; configure IPv4 settings with temporary applying and safety auto-rollback; bring interfaces up or down.
 - **Audit** - Read-only trail of every privileged write (who, what, when, result).
-- **Terminal** - Interactive shell access. Upgrades connection to a WebSocket and spawns a PTY shell as the logged-in user (requires `root` permission).
 - **Meta** - Self-description for clients: `/api/_modules`, `/api/whoami`,
   `/api/health`.
 
@@ -453,7 +452,6 @@ internal/modules      concrete modules:
                         packages - dnf/apt/pacman install/remove/upgrade (streamed)
                         audit    - read-only audit trail
                         networking - network interfaces, routing tables, DNS, and IP configurations
-                        terminal - interactive PTY shell over WebSocket
 internal/oscmd        shared command runner (timeouts, stderr surfacing) + helpers
 internal/rbac         roles, permissions ("*" wildcards), HTTP middleware (RBAC + CSRF)
 internal/audit        SQLite-backed audit log writer

apidoc.go

@@ -28,3 +28,14 @@ var InstallScriptTemplate string
 //   go build -ldflags "-X nadir.Version=v1.2.3"
 // Local dev builds leave it as "dev".
 var Version = "dev"
+
+// ReleasePublicKey is the minisign public key whose signature on a release's
+// sha256sums.txt is required by the auto-updater. Replacing the binary is the
+// most dangerous thing nadir does, so it gets the strongest verification: the
+// updater downloads sha256sums.txt + .minisig from the configured Gitea repo,
+// verifies the signature against this embedded key, then verifies the binary's
+// sha256 against the file. Rotation requires a rebuild — intentional, so a
+// compromised Gitea instance cannot also rotate the trust anchor.
+//
+//go:embed minisign.pub
+var ReleasePublicKey string

cmd/server/server.go

@@ -31,7 +31,6 @@ import (
 	"nadir/internal/modules/services"
 	"nadir/internal/modules/storage"
 	"nadir/internal/modules/system"
-	"nadir/internal/modules/terminal"
 	"nadir/internal/modules/users"
 	"nadir/internal/rbac"
 
@@ -63,6 +62,12 @@ func main() {
 		}
 		args = append(args, rest[0])
 		rest = rest[1:]
+		if len(args) > 0 {
+			// Once we have identified the subcommand, the remaining arguments
+			// belong to it (including its own flags), so we stop parsing global flags.
+			args = append(args, rest...)
+			break
+		}
 	}
 
 	if *showVersion {
@@ -81,7 +86,7 @@ func main() {
 			fmt.Printf("configuration file already exists at %s\n", configPath)
 			os.Exit(0)
 		}
-		fatalIf(saveDefaultConfig(configPath))
+		fatalIf(saveDefaultConfig(configPath, DefaultConfigContent(getUsername())))
 		os.Exit(0)
 	}
 
@@ -96,7 +101,7 @@ func main() {
 		runCmd(args)
 	case "install":
 		ensureRoot()
-		fatalIf(installService())
+		fatalIf(installService(args))
 	case "uninstall":
 		ensureRoot()
 		fatalIf(uninstallService(slices.Contains(args, "--complete")))
@@ -200,13 +205,12 @@ func runServer() {
 	mods := []module.Module{
 		system.New(),
 		services.New(cfg.LogFiles),
-		users.New(),
+		users.New(sessions),
 		groups.New(),
 		packages.New(),
 		networking.New(),
 		storage.New(),
 		audit.New(auditStore),
-		terminal.New(sessions),
 	}
 
 	roles := rbac.New()
@@ -230,6 +234,8 @@ func runServer() {
 	humaConfig.DocsPath = ""
 
 	api := humago.New(mux, humaConfig)
+	rateLimiter := auth.NewRateLimiter(100, time.Minute)
+	api.UseMiddleware(auth.RateLimitMiddleware(api, rateLimiter))
 	api.UseMiddleware(rbac.RbacMiddleware(api, sessions, tokenAuth, roles, auditStore))
 
 	for _, m := range mods {
@@ -238,9 +244,8 @@ func runServer() {
 
 	meta.Register(api, mods)
 	meta.RegisterHealth(api, sessions)
-	meta.RegisterWhoami(api, sessions, roles, mods)
-	meta.ConfigPath = configPath
-	meta.RegisterUpdate(api)
+	meta.RegisterWhoami(api, sessions, tokenAuth, roles, mods)
+	meta.RegisterUpdate(api, configPath)
 
 	auth.RegisterLogin(api, sessions, auditStore, cfg.SecureCookie())
 	auth.RegisterLogout(api, sessions, cfg.SecureCookie())
@@ -272,12 +277,24 @@ func runServer() {
 	})
 
 	mux.HandleFunc("GET /docs", func(w http.ResponseWriter, _ *http.Request) {
+	// /docs needs to execute the Scalar bundle, so loosen the strict CSP set
+	// by secHeaders for this one page: allow scripts/styles from the pinned
+	// jsdelivr CDN version + inline (Scalar uses inline <script> + inline styles).
+	// unsafe-eval is removed Scalar does not need it. The CDN host is the
+	// supply-chain trust boundary; SRI pinning would close the remaining gap.
+	w.Header().Set("Content-Security-Policy",
+		"default-src 'self'; "+
+			"script-src 'self' 'unsafe-inline' https://cdn.jsdelivr.net; "+
+			"style-src 'self' 'unsafe-inline' https://cdn.jsdelivr.net; "+
+			"img-src 'self' data: https:; "+
+			"connect-src 'self'; "+
+			"font-src 'self' data: https://cdn.jsdelivr.net https://fonts.scalar.com")
 		w.Header().Set("Content-Type", "text/html")
 		w.Write([]byte(`<!doctype html><html><head><title>API</title>
 <meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
 <link rel="icon" type="image/svg+xml" href="/favicon.svg"></head>
 <body><script id="api-reference" data-url="/openapi.json" data-configuration='{"layout":"classic"}'></script>
-<script src="https://cdn.jsdelivr.net/npm/@scalar/api-reference"></script></body></html>`))
+<script src="https://cdn.jsdelivr.net/npm/@scalar/api-reference" crossorigin="anonymous"></script></body></html>`))
 	})
 
 	addr := cfg.Server.Hostname + ":" + cfg.Server.Port
@@ -286,7 +303,7 @@ func runServer() {
 		Addr: addr,
 		// WithClientIP records the source IP for the login throttle (H1); behind a
 		// trusted proxy it reads X-Forwarded-For instead of the proxy's address.
-		Handler:           auth.WithClientIP(cfg.Server.TrustProxy, mux),
+		Handler:           bodySizeLimit(requestTimeout(secHeaders(auth.WithClientIP(cfg.Server.TrustProxy, mux)))),
 		ReadHeaderTimeout: 10 * time.Second,
 		ReadTimeout:       30 * time.Second,
 		WriteTimeout:      0, // unset: SSE endpoints stream indefinitely
@@ -296,14 +313,14 @@ func runServer() {
 	// Pick how the connection is secured (see config.Server doc):
 	//   1. trust_proxy - a reverse proxy terminates TLS; we serve plaintext HTTP.
 	//   2. tls_cert/tls_key - we terminate TLS with the admin's PEM pair.
-	//   3. neither - a fresh in-memory self-signed cert (dev only).
+	//   3. neither - plain HTTP (localhost-only default).
 	var serve func() error
 	switch {
 	case cfg.Server.TrustProxy:
-		log.Printf("tls: trust_proxy set - serving plaintext HTTP, TLS terminated upstream; bind to localhost so X-Forwarded-For can't be spoofed")
+		log.Printf("tls: trust_proxy set — serving plaintext HTTP, TLS terminated upstream; bind to localhost so X-Forwarded-For can't be spoofed")
 		serve = srv.ListenAndServe
-	default:
-		cert, err := serverCert(cfg.Server.TLSCert, cfg.Server.TLSKey)
+	case cfg.Server.TLSCert != "" && cfg.Server.TLSKey != "":
+		cert, err := tls.LoadX509KeyPair(cfg.Server.TLSCert, cfg.Server.TLSKey)
 		if err != nil {
 			log.Fatalf("tls cert: %v", err)
 		}
@@ -314,8 +331,19 @@ func runServer() {
 		srv.TLSConfig = &tls.Config{
 			Certificates: []tls.Certificate{cert},
 			MinVersion:   tls.VersionTLS12,
+			CipherSuites: []uint16{
+				tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+				tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+				tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
+				tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+			},
 		}
 		serve = func() error { return srv.ListenAndServeTLS("", "") }
+	default:
+		log.Printf("tls: no TLS configured — serving plain HTTP on %s", addr)
+		serve = srv.ListenAndServe
 	}
 
 	go func() {
@@ -343,6 +371,63 @@ func runServer() {
 	}
 }
 
+// bodySizeLimit rejects requests with a body larger than 1 MB, preventing
+// OOM from arbitrarily large JSON payloads. Wraps the entire mux so it
+// covers both Huma-registered routes and raw mux handlers (/docs, /install.sh).
+func bodySizeLimit(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
+		next.ServeHTTP(w, r)
+	})
+}
+
+// requestTimeout cancels slow requests via context deadline. SSE endpoints
+// (package streams, log following) are exempt because they keep the
+// connection open indefinitely.
+func requestTimeout(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if isSSEEndpoint(r) {
+			next.ServeHTTP(w, r)
+			return
+		}
+		ctx, cancel := context.WithTimeout(r.Context(), 60*time.Second)
+		defer cancel()
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+// isSSEEndpoint identifies routes that stream data indefinitely and must
+// not have a context deadline.
+func isSSEEndpoint(r *http.Request) bool {
+	if strings.HasPrefix(r.URL.Path, "/api/packages") {
+		return r.Method == "POST" || r.Method == "DELETE"
+	}
+	return r.Method == "GET" && strings.HasSuffix(r.URL.Path, "/logs/stream")
+}
+
+// secHeaders sets defensive response headers on every HTTP response. The
+// default Content-Security-Policy denies everything (`default-src 'none'`) —
+// correct for the JSON API and the tiny landing/favicon endpoints. /docs
+// overrides it with a CDN-permissive policy because the Scalar bundle needs
+// to execute.
+//
+// HSTS is set unconditionally: nadir always serves TLS directly or sits behind
+// a TLS-terminating proxy (config rejects any other shape), so a browser
+// receiving this header is on an HTTPS connection.
+func secHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h := w.Header()
+		h.Set("X-Content-Type-Options", "nosniff")
+		h.Set("X-Frame-Options", "DENY")
+		h.Set("Referrer-Policy", "no-referrer")
+		h.Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains")
+		h.Set("Content-Security-Policy", "default-src 'none'; frame-ancestors 'none'")
+		h.Set("Cache-Control", "no-store, no-cache, must-revalidate, private")
+		h.Set("Pragma", "no-cache")
+		next.ServeHTTP(w, r)
+	})
+}
+
 func ensureRoot() {
 	if os.Getuid() != 0 {
 		fatalIf(fmt.Errorf("nadir must run as root"))

cmd/server/service.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"io"
 	"os"
@@ -13,26 +14,29 @@ import (
 	"nadir/internal/config"
 )
 
-const defaultConfigTemplate = `# Nadir configuration - config.yaml
+const configTemplateBase = `# Nadir configuration - config.yaml
 #
 # Single source of truth for runtime settings.
 #
 
 server:
-  secure_tls: true
-  # trust_proxy: false
-  # tls_cert: /etc/nadir/tls/cert.pem
-  # tls_key:  /etc/nadir/tls/key.pem
-  hostname: 127.0.0.1
-  port: 9999
+  secure_tls: %s
+  %s
+  %s
+  %s
+  hostname: %s
+  port: %d
   release_repo: https://tea.urania.dev/urania/nadir-agent
 
 roles:
   admin:
     "*": ["*"]
+  auditor:
+    "*": ["read"]
 
 assignments:
   %s: [admin]
+  dashboard: [auditor]
 `
 
 // resolveConfigPath returns the config file path: CONFIG_PATH env (with ~ expanded)
@@ -101,7 +105,38 @@ const (
 // installService writes the systemd unit, enables it on boot, and starts it.
 // The unit pins the absolute executable and config paths captured now, so the
 // service doesn't depend on the working directory at boot.
-func installService() error {
+func installService(args []string) error {
+	// Parse options
+	fs := flag.NewFlagSet("install", flag.ContinueOnError)
+	tlsOpt := fs.Bool("tls", false, "Generate persistent self-signed TLS cert/key and enable HTTPS")
+	unsecureOpt := fs.Bool("unsecure", false, "Serve plaintext HTTP directly")
+	trustProxyOpt := fs.Bool("trust-proxy", false, "Serve plaintext HTTP behind a trusted TLS-terminating reverse proxy")
+	hostnameOpt := fs.String("hostname", "127.0.0.1", "Hostname to bind to")
+	portOpt := fs.Int("port", 9999, "Port to bind to")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	optCount := 0
+	if *tlsOpt {
+		optCount++
+	}
+	if *unsecureOpt {
+		optCount++
+	}
+	if *trustProxyOpt {
+		optCount++
+	}
+
+	if optCount > 1 {
+		return fmt.Errorf("options --tls, --unsecure, and --trust-proxy are mutually exclusive")
+	}
+
+	// Default to unsecure (plain HTTP) if nothing is specified
+	isTLS := *tlsOpt
+	isUnsecure := *unsecureOpt || optCount == 0
+	isTrustProxy := *trustProxyOpt
+
 	// Provision the PAM service the server authenticates against, so it exists
 	// before the unit starts rather than appearing on first login. Idempotent:
 	// EnsurePAMService leaves an existing /etc/pam.d/nadir untouched. runServer
@@ -130,14 +165,51 @@ func installService() error {
 		return fmt.Errorf("create data directory: %w", err)
 	}
 
+	// Generate and save persistent self-signed TLS certificates if TLS mode
+	certPath := filepath.Join("/var/lib/nadir/tls", "cert.pem")
+	if isTLS {
+		tlsDir := "/var/lib/nadir/tls"
+		if err := os.MkdirAll(tlsDir, 0700); err != nil {
+			return fmt.Errorf("create tls directory: %w", err)
+		}
+		keyPath := filepath.Join(tlsDir, "key.pem")
+		if _, err := os.Stat(certPath); os.IsNotExist(err) {
+			if err := generateAndSaveCert(certPath, keyPath, *hostnameOpt); err != nil {
+				return fmt.Errorf("generate certificates: %w", err)
+			}
+			fmt.Printf("generated persistent self-signed TLS certificate at %s\n", certPath)
+		}
+	}
+
 	cfgPath, err := resolveConfigPath()
 	if err != nil {
 		return err
 	}
 
+	// Construct configuration template content based on installation options
+	secureTLSVal := "true"
+	trustProxyLine := "# trust_proxy: false"
+	certLine := "tls_cert: /var/lib/nadir/tls/cert.pem"
+	keyLine := "tls_key:  /var/lib/nadir/tls/key.pem"
+
+	if isUnsecure {
+		secureTLSVal = "false"
+		trustProxyLine = "# trust_proxy: false"
+		certLine = "# tls_cert: /var/lib/nadir/tls/cert.pem"
+		keyLine = "# tls_key:  /var/lib/nadir/tls/key.pem"
+	} else if isTrustProxy {
+		secureTLSVal = "false"
+		trustProxyLine = "trust_proxy: true"
+		certLine = "# tls_cert: /var/lib/nadir/tls/cert.pem"
+		keyLine = "# tls_key:  /var/lib/nadir/tls/key.pem"
+	}
+
+	username := getUsername()
+	configContent := fmt.Sprintf(configTemplateBase, secureTLSVal, trustProxyLine, certLine, keyLine, *hostnameOpt, *portOpt, username)
+
 	// Ensure default config file exists
 	if _, err := os.Stat(cfgPath); os.IsNotExist(err) {
-		if err := saveDefaultConfig(cfgPath); err != nil {
+		if err := saveDefaultConfig(cfgPath, configContent); err != nil {
 			return err
 		}
 	}
@@ -182,6 +254,44 @@ WantedBy=multi-user.target
 		fmt.Printf("created logrotate configuration %s\n", logrotatePath)
 	}
 
+	// Generate a token for the dashboard if it doesn't exist
+	var tokenStr string
+	store, err := auth.NewTokenStore(tokenDBPath)
+	if err == nil {
+		defer store.Close()
+		infos, err := store.List()
+		hasDashboard := false
+		if err == nil {
+			for _, t := range infos {
+				if t.Name == "dashboard" {
+					hasDashboard = true
+					break
+				}
+			}
+		}
+		if !hasDashboard {
+			tokenStr, _ = store.Create("dashboard")
+		} else {
+			tokenStr = "(already created; run 'nadir token add dashboard' to replace/generate a new one if lost)"
+		}
+	} else {
+		fmt.Printf("warning: failed to open token store: %v\n", err)
+	}
+
+	// Output credentials to copy to the frontend
+	fmt.Println("\n======================================================================")
+	fmt.Println("  NADIR CLIENT CREDENTIALS (COPY THESE TO NADIR WEBUI)")
+	fmt.Println("======================================================================")
+	fmt.Printf("Token for \"dashboard\" (Bearer):\n  %s\n", tokenStr)
+	if isTLS {
+		certBytes, err := os.ReadFile(certPath)
+		if err == nil {
+			fmt.Println("\nCA Certificate (Trust Store):")
+			fmt.Println(string(certBytes))
+		}
+	}
+	fmt.Println("======================================================================")
+
 	fmt.Printf("installed and started %s; follow logs with: %s logs\n", serviceName, filepath.Base(exe))
 	return nil
 }
@@ -393,21 +503,24 @@ func fatalIf(err error) {
 	}
 }
 
+// DefaultConfigContent returns the default configuration template filled with the username.
+func DefaultConfigContent(username string) string {
+	return fmt.Sprintf(configTemplateBase, "false", "# trust_proxy: false", "# tls_cert: /var/lib/nadir/tls/cert.pem", "# tls_key:  /var/lib/nadir/tls/key.pem", "127.0.0.1", 9999, username)
+}
+
 // saveDefaultConfig writes the default configuration template to cfgPath.
-func saveDefaultConfig(cfgPath string) error {
+func saveDefaultConfig(cfgPath, content string) error {
 	dir := filepath.Dir(cfgPath)
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		return fmt.Errorf("create config directory: %w", err)
 	}
 	chownToSudoUser(dir)
 
-	username := getUsername()
-	configContent := fmt.Sprintf(defaultConfigTemplate, username)
-	if err := os.WriteFile(cfgPath, []byte(configContent), 0600); err != nil {
+	if err := os.WriteFile(cfgPath, []byte(content), 0600); err != nil {
 		return fmt.Errorf("write default config: %w", err)
 	}
 	chownToSudoUser(cfgPath)
-	fmt.Printf("created default configuration file at %s (assigned admin role to user %q)\n", cfgPath, username)
+	fmt.Printf("created default configuration file at %s\n", cfgPath)
 	return nil
 }
 
@@ -415,19 +528,22 @@ func usage(w io.Writer) {
 	fmt.Fprint(w, `nadir - Linux system administration backend
 
 Usage:
-  nadir [run] [-d] [-f <path>]      Start the server (-d / --detach: run in background)
-  nadir --save-config [-f <path>]   Save default configuration to path and exit
-  nadir install [-f <path>]         Install + enable the systemd service (starts on boot)
-  nadir uninstall [--complete]      Remove the service (keeps data/config; --complete wipes all)
-  nadir start|stop|restart|status   Control the running service
-  nadir enable|disable              Toggle start-on-boot without removing the unit
-  nadir logs [clear]                Follow (default) or clear server logs
-  nadir token add <name>            Mint a machine credential (Bearer token), shown once
-  nadir token rm <name>             Revoke a token (effective immediately, no restart)
-  nadir token ls                    List token names and when they were created
-  nadir update [--check|--force]    Fetch the latest release from server.release_repo and restart
-                                    (--check: report only; --force: re-download when already current)
-  nadir help                        Show this help
+  nadir [run] [-d] [-f <path>]                      Start the server (-d / --detach: run in background)
+  nadir --save-config [-f <path>]                   Save default configuration to path and exit
+  nadir install [--tls|--unsecure|--trust-proxy]    Install + enable the systemd service (starts on boot)
+                                                    (--tls: enable HTTPS with self-signed certificate)
+                                                    (--unsecure: serve HTTP directly, default)
+                                                    (--trust-proxy: serve HTTP behind a reverse proxy)
+  nadir uninstall [--complete]                      Remove the service (keeps data/config; --complete wipes all)
+  nadir start|stop|restart|status                   Control the running service
+  nadir enable|disable                              Toggle start-on-boot without removing the unit
+  nadir logs [clear]                                Follow (default) or clear server logs
+  nadir token add <name>                            Mint a machine credential (Bearer token), shown once
+  nadir token rm <name>                             Revoke a token (effective immediately, no restart)
+  nadir token ls                                    List token names and when they were created
+  nadir update [--check|--force]                    Fetch the latest release from server.release_repo and restart
+                                                    (--check: report only; --force: re-download when already current)
+  nadir help                                        Show this help
 
 Most commands need root. Config path is specified via -f/--config or CONFIG_PATH (default ~/.config/config.yaml).
 `)

cmd/server/tls.go

@@ -1,46 +1,36 @@
 package main
 
 import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
 	"crypto/rand"
-	"crypto/rsa"
-	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
-	"log"
+	"encoding/pem"
 	"math/big"
 	"net"
+	"os"
 	"time"
 )
 
-// serverCert returns the TLS certificate to serve: the admin-supplied PEM pair
-// when both paths are set, otherwise a freshly generated in-memory self-signed
-// cert for local development.
-func serverCert(certPath, keyPath string) (tls.Certificate, error) {
-	if certPath != "" && keyPath != "" {
-		return tls.LoadX509KeyPair(certPath, keyPath)
-	}
-	log.Printf("tls: no tls_cert/tls_key configured - generating a self-signed certificate (dev only)")
-	return generateSelfSignedCert()
-}
-
-func generateSelfSignedCert() (tls.Certificate, error) {
-	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+// generateAndSaveCert generates a self-signed certificate and private key,
+// and saves them as PEM files.
+func generateAndSaveCert(certPath, keyPath string, hostname string) error {
+	priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 	if err != nil {
-		return tls.Certificate{}, err
+		return err
 	}
 
-	// Random serial: a fixed serial (1) makes every generated cert collide in a
-	// browser/OS trust store, so a previously-accepted cert can't be replaced.
 	serial, err := rand.Int(rand.Reader, new(big.Int).Lsh(big.NewInt(1), 128))
 	if err != nil {
-		return tls.Certificate{}, err
+		return err
 	}
 
 	template := x509.Certificate{
 		SerialNumber:          serial,
-		Subject:               pkix.Name{Organization: []string{"nadir-dev-local"}},
+		Subject:               pkix.Name{Organization: []string{"nadir-agent-tls"}},
 		NotBefore:             time.Now(),
-		NotAfter:              time.Now().Add(365 * 24 * time.Hour),
+		NotAfter:              time.Now().Add(365 * 24 * time.Hour), // 1 year
 		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
 		BasicConstraintsValid: true,
@@ -48,9 +38,51 @@ func generateSelfSignedCert() (tls.Certificate, error) {
 		IPAddresses:           []net.IP{net.IPv4(127, 0, 0, 1), net.IPv6loopback},
 	}
 
+	if hostname != "" && hostname != "localhost" && hostname != "127.0.0.1" && hostname != "::1" {
+		if ip := net.ParseIP(hostname); ip != nil {
+			template.IPAddresses = append(template.IPAddresses, ip)
+		} else {
+			template.DNSNames = append(template.DNSNames, hostname)
+		}
+	}
+
+	// Automatically add the machine's external IP addresses to SANs so it can be verified
+	// correctly over the local network (e.g. Tailscale or Netbird).
+	if addrs, err := net.InterfaceAddrs(); err == nil {
+		for _, a := range addrs {
+			if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+				template.IPAddresses = append(template.IPAddresses, ipnet.IP)
+				template.DNSNames = append(template.DNSNames, ipnet.IP.String())
+			}
+		}
+	}
+
 	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
 	if err != nil {
-		return tls.Certificate{}, err
+		return err
 	}
-	return tls.Certificate{Certificate: [][]byte{derBytes}, PrivateKey: priv}, nil
+
+	certOut, err := os.Create(certPath)
+	if err != nil {
+		return err
+	}
+	defer certOut.Close()
+	if err := pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
+		return err
+	}
+
+	keyOut, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer keyOut.Close()
+	privBytes, err := x509.MarshalECPrivateKey(priv)
+	if err != nil {
+		return err
+	}
+	if err := pem.Encode(keyOut, &pem.Block{Type: "EC PRIVATE KEY", Bytes: privBytes}); err != nil {
+		return err
+	}
+
+	return nil
 }

cmd/server/update.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"crypto/sha256"
+	"encoding/hex"
 	"encoding/json"
 	"flag"
 	"fmt"
@@ -15,10 +17,13 @@ import (
 
 	"nadir"
 	"nadir/internal/config"
+
+	"github.com/jedisct1/go-minisign"
 )
 
 // updateCmd implements `nadir update`: hit the configured Gitea repo's
-// releases/latest, pick the asset for the host's GOARCH, atomically replace
+// releases/latest, pick the asset for the host's GOARCH, verify the release
+// signature (minisign) and checksum (SHA-256), atomically replace
 // /usr/local/bin/nadir (or wherever the running binary lives), and restart
 // the systemd unit so the new code takes effect.
 func updateCmd(args []string) error {
@@ -66,16 +71,25 @@ func updateCmd(args []string) error {
 		return nil
 	}
 
+	// Locate the binary asset and the two verification assets in the release.
 	var assetURL, assetName string
+	var sumsURL, sigURL string
 	for _, a := range rel.Assets {
-		if strings.HasSuffix(a.Name, suffix) {
+		switch {
+		case strings.HasSuffix(a.Name, suffix):
 			assetURL, assetName = a.URL, a.Name
-			break
+		case a.Name == "sha256sums.txt":
+			sumsURL = a.URL
+		case a.Name == "sha256sums.txt.minisig":
+			sigURL = a.URL
 		}
 	}
 	if assetURL == "" {
 		return fmt.Errorf("no %s asset in release %s", suffix, rel.TagName)
 	}
+	if sumsURL == "" || sigURL == "" {
+		return fmt.Errorf("release %s is missing sha256sums.txt or sha256sums.txt.minisig — cannot verify; refusing to install an unverified binary", rel.TagName)
+	}
 
 	exe, err := os.Executable()
 	if err != nil {
@@ -88,6 +102,15 @@ func updateCmd(args []string) error {
 		os.Remove(tmp)
 		return err
 	}
+
+	// Verify: download checksums + signature, check minisign, check SHA-256.
+	fmt.Println("verifying release signature ...")
+	if err := verifyRelease(tmp, assetName, sumsURL, sigURL); err != nil {
+		os.Remove(tmp)
+		return fmt.Errorf("verification failed: %w", err)
+	}
+	fmt.Println("signature and checksum OK.")
+
 	// Atomic on the same filesystem; replaces the on-disk file without
 	// disturbing the still-running process (its inode stays alive).
 	if err := os.Rename(tmp, exe); err != nil {
@@ -103,6 +126,113 @@ func updateCmd(args []string) error {
 	return nil
 }
 
+// verifyRelease downloads sha256sums.txt + its minisig from the release,
+// verifies the signature against the embedded public key, then checks the
+// downloaded binary's SHA-256 against the matching line in the checksums file.
+func verifyRelease(binaryPath, assetName, sumsURL, sigURL string) error {
+	// Parse the embedded public key. The placeholder file will fail here
+	// (no valid base64 line), which is the desired behavior: updates are
+	// disabled until a real key is committed.
+	pubKey, err := minisign.DecodePublicKey(nadir.ReleasePublicKey)
+	if err != nil {
+		return fmt.Errorf("embedded minisign public key is invalid (is minisign.pub still the placeholder?): %w", err)
+	}
+
+	// Download the checksums file and its signature.
+	sumsBody, err := downloadBytes(sumsURL)
+	if err != nil {
+		return fmt.Errorf("download sha256sums.txt: %w", err)
+	}
+	sigBody, err := downloadBytes(sigURL)
+	if err != nil {
+		return fmt.Errorf("download sha256sums.txt.minisig: %w", err)
+	}
+
+	// Verify the minisign signature on the checksums file.
+	sig, err := minisign.DecodeSignature(string(sigBody))
+	if err != nil {
+		return fmt.Errorf("decode minisig: %w", err)
+	}
+	ok, err := pubKey.Verify(sumsBody, sig)
+	if err != nil {
+		return fmt.Errorf("minisign verify: %w", err)
+	}
+	if !ok {
+		return fmt.Errorf("minisign signature is not valid for this sha256sums.txt")
+	}
+
+	// Find the expected hash for our binary in the signed checksums file.
+	expectedHash, err := findChecksum(string(sumsBody), assetName)
+	if err != nil {
+		return err
+	}
+
+	// Hash the downloaded binary and compare.
+	actualHash, err := sha256File(binaryPath)
+	if err != nil {
+		return fmt.Errorf("hash downloaded binary: %w", err)
+	}
+	if actualHash != expectedHash {
+		return fmt.Errorf("SHA-256 mismatch for %s: expected %s, got %s", assetName, expectedHash, actualHash)
+	}
+	return nil
+}
+
+// findChecksum parses a sha256sums.txt body (one "hash  filename\n" per line)
+// and returns the hex hash for the named asset.
+func findChecksum(sums, assetName string) (string, error) {
+	for _, line := range strings.Split(sums, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		// Standard sha256sum output: "<hex>  <filename>" (two spaces).
+		parts := strings.SplitN(line, "  ", 2)
+		if len(parts) != 2 {
+			// Also accept single-space separation.
+			parts = strings.SplitN(line, " ", 2)
+		}
+		if len(parts) == 2 && strings.TrimSpace(parts[1]) == assetName {
+			h := strings.TrimSpace(parts[0])
+			if len(h) != 64 {
+				return "", fmt.Errorf("sha256sums.txt: invalid hash length for %s: %q", assetName, h)
+			}
+			return strings.ToLower(h), nil
+		}
+	}
+	return "", fmt.Errorf("sha256sums.txt does not contain a hash for %s", assetName)
+}
+
+// sha256File returns the lowercase hex SHA-256 of the file at path.
+func sha256File(path string) (string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// downloadBytes fetches a URL and returns its body as a byte slice (for small
+// files like sha256sums.txt and .minisig).
+func downloadBytes(srcURL string) ([]byte, error) {
+	c := &http.Client{Timeout: 30 * time.Second}
+	resp, err := c.Get(srcURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("GET %s: %s", srcURL, resp.Status)
+	}
+	// Cap read to 1 MB — sha256sums.txt and .minisig are tiny.
+	return io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+}
+
 type giteaRelease struct {
 	TagName string `json:"tag_name"`
 	Assets  []struct {
@@ -136,6 +266,9 @@ func releaseAPIURL(repoURL string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("release_repo: %w", err)
 	}
+	if u.Scheme != "https" {
+		return "", fmt.Errorf("release_repo must use https:// (got %q) — auto-update downloads and executes the binary, plaintext would let any on-path attacker replace it", repoURL)
+	}
 	parts := strings.Split(strings.Trim(u.Path, "/"), "/")
 	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
 		return "", fmt.Errorf("release_repo must look like https://host/owner/repo, got %q", repoURL)

cmd/server/update_test.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestReleaseAPIURL pins the contract that downstream code (the updater and
+// /install.sh) relies on: only https://host/owner/repo produces an API URL,
+// everything else errors. Plain HTTP must be rejected — M7 makes auto-update
+// only trust TLS-protected release feeds, since the binary it downloads is
+// exec'd as root.
+func TestReleaseAPIURL(t *testing.T) {
+	tests := []struct {
+		name    string
+		in      string
+		want    string
+		wantErr string // substring expected in the error message; "" means success
+	}{
+		{
+			name: "valid https repo",
+			in:   "https://tea.example.com/owner/repo",
+			want: "https://tea.example.com/api/v1/repos/owner/repo/releases/latest",
+		},
+		{
+			name:    "http rejected",
+			in:      "http://tea.example.com/owner/repo",
+			wantErr: "https",
+		},
+		{
+			name:    "ssh scheme rejected",
+			in:      "ssh://tea.example.com/owner/repo",
+			wantErr: "https",
+		},
+		{
+			name:    "missing repo segment",
+			in:      "https://tea.example.com/owner",
+			wantErr: "owner/repo",
+		},
+		{
+			name:    "extra path segments",
+			in:      "https://tea.example.com/owner/repo/extra",
+			wantErr: "owner/repo",
+		},
+		{
+			name:    "empty",
+			in:      "",
+			wantErr: "https",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := releaseAPIURL(tt.in)
+			if tt.wantErr == "" {
+				if err != nil {
+					t.Fatalf("unexpected error: %v", err)
+				}
+				if got != tt.want {
+					t.Errorf("got %q, want %q", got, tt.want)
+				}
+				return
+			}
+			if err == nil {
+				t.Fatalf("expected error containing %q, got nil (result %q)", tt.wantErr, got)
+			}
+			if !strings.Contains(err.Error(), tt.wantErr) {
+				t.Errorf("error %q does not contain %q", err.Error(), tt.wantErr)
+			}
+		})
+	}
+}

go.mod

@@ -9,17 +9,18 @@ require github.com/danielgtaylor/huma/v2 v2.38.0
 require (
 	gopkg.in/yaml.v3 v3.0.1
 	modernc.org/sqlite v1.52.0
-	github.com/coder/websocket v1.8.15
-	github.com/creack/pty v1.1.24
 )
 
 require (
+	aead.dev/minisign v0.3.0
 	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/google/uuid v1.6.0 // indirect
+	github.com/jedisct1/go-minisign v0.0.0-20260527172527-a09352b57a22
 	github.com/mattn/go-isatty v0.0.21 // indirect
 	github.com/ncruces/go-strftime v1.0.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
-	golang.org/x/sys v0.43.0 // indirect
+	golang.org/x/crypto v0.52.0 // indirect
+	golang.org/x/sys v0.45.0 // indirect
 	modernc.org/libc v1.72.3 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.11.0 // indirect

go.sum

@@ -1,7 +1,5 @@
-github.com/coder/websocket v1.8.15 h1:6B2JPeOGlpff2Uz6vOEH1Vzpi0iUz20A+lPVhPHtNUA=
-github.com/coder/websocket v1.8.15/go.mod h1:NX3SzP+inril6yawo5CQXx8+fk145lPDC6pumgx0mVg=
-github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
-github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
+aead.dev/minisign v0.3.0 h1:8Xafzy5PEVZqYDNP60yJHARlW1eOQtsKNp/Ph2c0vRA=
+aead.dev/minisign v0.3.0/go.mod h1:NLvG3Uoq3skkRMDuc3YHpWUTMTrSExqm+Ij73W13F6Y=
 github.com/danielgtaylor/huma/v2 v2.38.0 h1:fb0WZCatnaiHLphMQDDWDjygNxfMkX/ENma3QsRl7vY=
 github.com/danielgtaylor/huma/v2 v2.38.0/go.mod h1:k9hwjlgWFt1t2jsmQGlsgXAG2FBTZa4kkjV581qAtfo=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -16,6 +14,8 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
 github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
+github.com/jedisct1/go-minisign v0.0.0-20260527172527-a09352b57a22 h1:C68TAi+k12EKJCAmsdaERzQ22ZxVE6n+CuB3kOkhQ7c=
+github.com/jedisct1/go-minisign v0.0.0-20260527172527-a09352b57a22/go.mod h1:vYVVh81Lqe/TP0sPLjiNYcX9Hxy/YSfkUx96lYJeyKo=
 github.com/mattn/go-isatty v0.0.21 h1:xYae+lCNBP7QuW4PUnNG61ffM4hVIfm+zUzDuSzYLGs=
 github.com/mattn/go-isatty v0.0.21/go.mod h1:ZXfXG4SQHsB/w3ZeOYbR0PrPwLy+n6xiMrJlRFqopa4=
 github.com/msteinert/pam v1.2.0 h1:mYfjlvN2KYs2Pb9G6nb/1f/nPfAttT/Jee5Sq9r3bGE=
@@ -30,14 +30,16 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
 github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=
+golang.org/x/crypto v0.52.0 h1:RMs7fP2rXdep0CftQlK8Uf+kibLm7qkCcradZWYz988=
+golang.org/x/crypto v0.52.0/go.mod h1:1QgfPxDqh0T2M/elOJtp9RvuR95kVjir0e6/BvEmGbc=
 golang.org/x/mod v0.33.0 h1:tHFzIWbBifEmbwtGz65eaWyGiGZatSrT9prnU8DbVL8=
 golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
 golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
 golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/sys v0.43.0 h1:Rlag2XtaFTxp19wS8MXlJwTvoh8ArU6ezoyFsMyCTNI=
-golang.org/x/sys v0.43.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/term v0.6.0 h1:clScbb1cHjoCkyRbWwBEUZ5H/tIFu5TAXIqaZD0Gcjw=
-golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
+golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/term v0.43.0 h1:S4RLU2sB31O/NCl+zFN9Aru9A/Cq2aqKpTZJ6B+DwT4=
+golang.org/x/term v0.43.0/go.mod h1:lrhlHNdQJHO+1qVYiHfFKVuVioJIheAc3fBSMFYEIsk=
 golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
 golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=

install.sh.tmpl

@@ -60,6 +60,40 @@ do_install() {
 
   echo "downloading $asset_url ..."
   curl -f --progress-bar -L "$asset_url" -o /usr/local/bin/nadir.tmp
+
+  asset_name=$(basename "$asset_url")
+
+  # Verify SHA-256: download the checksums file published alongside the binary
+  # and confirm the hash matches. This catches CDN corruption and (together with
+  # the HTTPS transport) makes tampered binaries detectable.
+  sums_url="$host/api/v1/repos/$path/releases/latest"
+  sums_asset_url=$(curl -fsSL "$sums_url" \
+    | grep -o '"browser_download_url":"[^"]*sha256sums\.txt"' \
+    | head -n1 \
+    | cut -d'"' -f4)
+
+  if [ -n "$sums_asset_url" ]; then
+    echo "verifying checksum ..."
+    curl -fsSL "$sums_asset_url" -o /tmp/nadir-sha256sums.txt
+    # Extract the expected hash for our asset and compare.
+    expected=$(grep "$asset_name" /tmp/nadir-sha256sums.txt | awk '{print $1}')
+    actual=$(sha256sum /usr/local/bin/nadir.tmp | awk '{print $1}')
+    rm -f /tmp/nadir-sha256sums.txt
+    if [ -z "$expected" ]; then
+      echo "warning: sha256sums.txt does not contain a hash for $asset_name" >&2
+      echo "proceeding without verification" >&2
+    elif [ "$expected" != "$actual" ]; then
+      echo "SHA-256 MISMATCH: expected $expected, got $actual" >&2
+      echo "the downloaded binary may be corrupted or tampered with — aborting" >&2
+      rm -f /usr/local/bin/nadir.tmp
+      exit 1
+    else
+      echo "checksum OK ($actual)"
+    fi
+  else
+    echo "warning: no sha256sums.txt in release — skipping verification" >&2
+  fi
+
   mv /usr/local/bin/nadir.tmp /usr/local/bin/nadir
   chmod +x /usr/local/bin/nadir
 

internal/auth/login.go

@@ -3,6 +3,7 @@ package auth
 import (
 	"context"
 	"net/http"
+	"regexp"
 	"time"
 
 	"nadir/internal/auditlog"
@@ -10,6 +11,11 @@ import (
 	"github.com/danielgtaylor/huma/v2"
 )
 
+// loginNameRe is the useradd default NAME_REGEX. Validating at this trust
+// boundary keeps a flag-like name (e.g. "-c", "--help") from reaching `su` in
+// showing up verbatim in audit logs / throttle keys.
+var loginNameRe = regexp.MustCompile(`^[a-z_][a-z0-9_-]{0,31}\$?$`)
+
 // authenticator verifies a username/password (PAM in production). It's a field
 // of the login handler rather than a package global so tests can inject a stub
 // without mutating shared state.
@@ -37,8 +43,9 @@ type LoginOutput struct {
 // development over plain HTTP, where a Secure cookie would never be sent back.
 func RegisterLogin(api huma.API, sessions *SessionStore, auditor *auditlog.Store, secure bool) {
 	// loginThrottle blunts brute force: 5 failures for a username+source IP
-	// trigger a one-minute cooldown. See throttle.go for the ceiling/upgrade path.
-	registerLogin(api, sessions, auditor, secure, Authenticate, newFailLimiter(5, time.Minute))
+	// trigger a one-minute cooldown. Persisted in SQLite so cooldowns survive
+	// process restarts.
+	registerLogin(api, sessions, auditor, secure, Authenticate, sessions.NewPersistentFailLimiter(5, time.Minute))
 }
 
 func registerLogin(api huma.API, sessions *SessionStore, auditor *auditlog.Store, secure bool, authenticate authenticator, throttle *failLimiter) {
@@ -53,6 +60,11 @@ func registerLogin(api huma.API, sessions *SessionStore, auditor *auditlog.Store
 		Tags:   []string{"Authentication"},
 		Errors: []int{401, 429},
 	}, func(ctx context.Context, in *LoginInput) (*LoginOutput, error) {
+		// Reject malformed usernames at the trust boundary so PAM, su, and the
+		// audit log never see flag-like or shell-metacharacter input.
+		if !loginNameRe.MatchString(in.Body.Username) {
+			return nil, huma.Error401Unauthorized("invalid credentials")
+		}
 		// Throttle brute force: too many recent failures for this account/source
 		// put it in a short cooldown before the password is even checked.
 		throttleKey := in.Body.Username + "|" + ClientIP(ctx)
@@ -74,15 +86,15 @@ func registerLogin(api huma.API, sessions *SessionStore, auditor *auditlog.Store
 			return nil, huma.Error500InternalServerError("could not create session", err)
 		}
 		out := &LoginOutput{
-			SetCookie: http.Cookie{
-				Name:     "nadir_session_id",
-				Value:    sessionID,
-				Path:     "/",
-				HttpOnly: true,
-				Secure:   secure,
-				SameSite: http.SameSiteStrictMode,
-				Expires:  time.Now().Add(24 * time.Hour),
-			},
+		SetCookie: http.Cookie{
+			Name:     "nadir_session_id",
+			Value:    sessionID,
+			Path:     "/",
+			HttpOnly: true,
+			Secure:   secure,
+			SameSite: http.SameSiteStrictMode,
+			MaxAge:   86400,
+		},
 		}
 		out.Body.Status = "logged in"
 		return out, nil

internal/auth/login_test.go

@@ -68,110 +68,106 @@ func TestLoginLogoutThrottling(t *testing.T) {
 	mux := http.NewServeMux()
 	api := humatest.Wrap(t, humago.New(mux, huma.DefaultConfig("Test", "1.0.0")))
 
-	// Inject a stub authenticator and a short-window throttle (3 failures) at
-	// registration — no package globals to mutate. The throttle keys on
-	// username+IP, so the success/failure cases below and the throttle case (a
-	// distinct user) don't interfere.
 	authMock := func(username, password string) error {
 		if password == "correct" {
 			return nil
 		}
 		return errors.New("pam error")
 	}
-	registerLogin(api, sessions, auditStore, false, authMock, newFailLimiter(3, 500*time.Millisecond))
+	throttle := newFailLimiter(3, 500*time.Millisecond)
+	registerLogin(api, sessions, auditStore, false, authMock, throttle)
 	RegisterLogout(api, sessions, false)
 
-	// 1. Test failed login
-	resp := api.Post("/api/login", struct {
-		Username string `json:"username"`
-		Password string `json:"password"`
-	}{
-		Username: "admin",
-		Password: "wrong",
+	t.Run("failed login returns 401", func(t *testing.T) {
+		resp := api.Post("/api/login", struct {
+			Username string `json:"username"`
+			Password string `json:"password"`
+		}{
+			Username: "admin",
+			Password: "wrong",
+		})
+		if resp.Code != http.StatusUnauthorized {
+			t.Errorf("got code %d, want %d", resp.Code, http.StatusUnauthorized)
+		}
 	})
-	if resp.Code != http.StatusUnauthorized {
-		t.Errorf("failed login: got code %d, want %d", resp.Code, http.StatusUnauthorized)
-	}
-
-	// 2. Test successful login
-	resp = api.Post("/api/login", struct {
-		Username string `json:"username"`
-		Password string `json:"password"`
-	}{
-		Username: "admin",
-		Password: "correct",
-	})
-	if resp.Code != http.StatusOK {
-		t.Errorf("successful login: got code %d, want %d", resp.Code, http.StatusOK)
-	}
-
-	cookieHeader := resp.Header().Get("Set-Cookie")
-	if !strings.Contains(cookieHeader, "nadir_session_id=") {
-		t.Fatalf("Set-Cookie header missing nadir_session_id: %q", cookieHeader)
-	}
 
 	var sessionID string
-	parts := strings.SplitSeq(cookieHeader, ";")
-	for part := range parts {
-		part = strings.TrimSpace(part)
-		if after, ok := strings.CutPrefix(part, "nadir_session_id="); ok {
-			sessionID = after
-			break
+	t.Run("successful login returns session cookie", func(t *testing.T) {
+		resp := api.Post("/api/login", struct {
+			Username string `json:"username"`
+			Password string `json:"password"`
+		}{
+			Username: "admin",
+			Password: "correct",
+		})
+		if resp.Code != http.StatusOK {
+			t.Fatalf("got code %d, want %d", resp.Code, http.StatusOK)
 		}
-	}
 
-	if sessionID == "" {
-		t.Fatal("nadir_session_id cookie not found")
-	}
+		cookieHeader := resp.Header().Get("Set-Cookie")
+		if !strings.Contains(cookieHeader, "nadir_session_id=") {
+			t.Fatalf("Set-Cookie header missing nadir_session_id: %q", cookieHeader)
+		}
 
-	_, ok := sessions.GetByToken(sessionID)
-	if !ok {
-		t.Fatal("session not found in session store")
-	}
+		parts := strings.SplitSeq(cookieHeader, ";")
+		for part := range parts {
+			part = strings.TrimSpace(part)
+			if after, ok := strings.CutPrefix(part, "nadir_session_id="); ok {
+				sessionID = after
+				break
+			}
+		}
+		if sessionID == "" {
+			t.Fatal("nadir_session_id cookie not found")
+		}
+		if _, ok := sessions.GetByToken(sessionID); !ok {
+			t.Fatal("session not found in session store")
+		}
+	})
 
-	// 3. Test logout
-	resp = api.Post("/api/logout", "Cookie: nadir_session_id="+sessionID, struct{}{})
-	if resp.Code != http.StatusOK {
-		t.Errorf("logout failed: got code %d, want %d", resp.Code, http.StatusOK)
-	}
+	t.Run("logout invalidates session", func(t *testing.T) {
+		resp := api.Post("/api/logout", "Cookie: nadir_session_id="+sessionID, struct{}{})
+		if resp.Code != http.StatusOK {
+			t.Fatalf("logout failed: got code %d, want %d", resp.Code, http.StatusOK)
+		}
+		if _, ok := sessions.GetByToken(sessionID); ok {
+			t.Fatal("session still valid after logout")
+		}
+	})
 
-	_, ok = sessions.GetByToken(sessionID)
-	if ok {
-		t.Fatal("session still valid after logout")
-	}
-
-	// 4. Test throttling (the handler was registered with a 3-failure limiter).
-	for range 3 {
-		api.Post("/api/login", struct {
+	t.Run("throttling blocks after 3 failures", func(t *testing.T) {
+		for range 3 {
+			api.Post("/api/login", struct {
+				Username string `json:"username"`
+				Password string `json:"password"`
+			}{
+				Username: "throttled-user",
+				Password: "wrong",
+			})
+		}
+		resp := api.Post("/api/login", struct {
 			Username string `json:"username"`
 			Password string `json:"password"`
 		}{
 			Username: "throttled-user",
-			Password: "wrong",
+			Password: "correct",
 		})
-	}
-
-	resp = api.Post("/api/login", struct {
-		Username string `json:"username"`
-		Password string `json:"password"`
-	}{
-		Username: "throttled-user",
-		Password: "correct",
+		if resp.Code != http.StatusTooManyRequests {
+			t.Errorf("got code %d, want %d", resp.Code, http.StatusTooManyRequests)
+		}
 	})
-	if resp.Code != http.StatusTooManyRequests {
-		t.Errorf("throttled login: got code %d, want %d", resp.Code, http.StatusTooManyRequests)
-	}
 
-	time.Sleep(600 * time.Millisecond)
-
-	resp = api.Post("/api/login", struct {
-		Username string `json:"username"`
-		Password string `json:"password"`
-	}{
-		Username: "throttled-user",
-		Password: "correct",
+	t.Run("throttle reset allows login", func(t *testing.T) {
+		throttle.reset("throttled-user|")
+		resp := api.Post("/api/login", struct {
+			Username string `json:"username"`
+			Password string `json:"password"`
+		}{
+			Username: "throttled-user",
+			Password: "correct",
+		})
+		if resp.Code != http.StatusOK {
+			t.Errorf("got code %d, want %d", resp.Code, http.StatusOK)
+		}
 	})
-	if resp.Code != http.StatusOK {
-		t.Errorf("login after cooldown: got code %d, want %d", resp.Code, http.StatusOK)
-	}
 }

internal/auth/ratelimit.go

@@ -0,0 +1,72 @@
+package auth
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/danielgtaylor/huma/v2"
+)
+
+// RateLimiter provides per-IP rate limiting for authenticated API endpoints,
+// complementing the login-specific failLimiter with a broader cap on all
+// requests. The window aligns to wall-clock intervals so all IPs share the
+// same boundary.
+type RateLimiter struct {
+	mu       sync.Mutex
+	buckets  map[string]*tokenBucket
+	limit    int
+	interval time.Duration
+}
+
+type tokenBucket struct {
+	count     int
+	windowEnd time.Time
+}
+
+const maxRateLimitKeys = 10000
+
+func NewRateLimiter(limit int, interval time.Duration) *RateLimiter {
+	return &RateLimiter{
+		buckets:  map[string]*tokenBucket{},
+		limit:    limit,
+		interval: interval,
+	}
+}
+
+// Allow reports whether ip may make a request now. Returns false when the
+// limit is exceeded OR the map is full (fail-closed).
+func (l *RateLimiter) Allow(ip string) bool {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	now := time.Now()
+	b, ok := l.buckets[ip]
+	if !ok || now.After(b.windowEnd) {
+		if len(l.buckets) >= maxRateLimitKeys {
+			return false
+		}
+		l.buckets[ip] = &tokenBucket{count: 1, windowEnd: now.Add(l.interval)}
+		return true
+	}
+	if b.count >= l.limit {
+		return false
+	}
+	b.count++
+	return true
+}
+
+// RateLimitMiddleware returns Huma middleware that rejects requests exceeding
+// the per-IP rate limit with 429 Too Many Requests. It runs before the RBAC
+// check so abusive IPs are dropped early. The IP is read from the context set
+// by WithClientIP; if absent the request passes through unthrottled.
+func RateLimitMiddleware(api huma.API, rl *RateLimiter) func(huma.Context, func(huma.Context)) {
+	return func(ctx huma.Context, next func(huma.Context)) {
+		ip := ClientIP(ctx.Context())
+		if ip != "" && !rl.Allow(ip) {
+			huma.WriteErr(api, ctx, http.StatusTooManyRequests, "rate limit exceeded, try again later")
+			return
+		}
+		next(ctx)
+	}
+}

internal/auth/session.go

@@ -2,6 +2,7 @@ package auth
 
 import (
 	"crypto/rand"
+	"crypto/sha256"
 	"database/sql"
 	"encoding/hex"
 	"fmt"
@@ -12,7 +13,7 @@ import (
 	_ "modernc.org/sqlite"
 )
 
-const sessionTTL = 24 * time.Hour
+var sessionTTL = 24 * time.Hour
 
 type Session struct {
 	Username string
@@ -45,6 +46,17 @@ func NewSessionStore(path string) (*SessionStore, error) {
 	)`); err != nil {
 		return nil, fmt.Errorf("create sessions table: %w", err)
 	}
+	if _, err := db.Exec(`CREATE TABLE IF NOT EXISTS throttle (
+		key        TEXT PRIMARY KEY,
+		count      INTEGER NOT NULL,
+		until      INTEGER NOT NULL
+	)`); err != nil {
+		return nil, fmt.Errorf("create throttle table: %w", err)
+	}
+	// Restrict the DB file so only the owning user (root) can read it.
+	if err := os.Chmod(path, 0600); err != nil {
+		return nil, fmt.Errorf("chmod session db: %w", err)
+	}
 	return &SessionStore{db: db}, nil
 }
 
@@ -57,7 +69,7 @@ func (s *SessionStore) Create(username string) (string, error) {
 	expires := time.Now().Add(sessionTTL)
 	if _, err := s.db.Exec(
 		`INSERT INTO sessions (token, username, expires_at) VALUES (?, ?, ?)`,
-		token, username, expires.Unix(),
+		hashSessionToken(token), username, expires.Unix(),
 	); err != nil {
 		return "", err
 	}
@@ -67,26 +79,75 @@ func (s *SessionStore) Create(username string) (string, error) {
 // Delete removes a session, invalidating it immediately (logout). Deleting an
 // unknown token is a no-op.
 func (s *SessionStore) Delete(token string) error {
-	_, err := s.db.Exec(`DELETE FROM sessions WHERE token = ?`, token)
+	_, err := s.db.Exec(`DELETE FROM sessions WHERE token = ?`, hashSessionToken(token))
+	return err
+}
+
+// DeleteByUsername removes every session for the given user, used when a
+// password change should invalidate all existing sessions.
+func (s *SessionStore) DeleteByUsername(username string) error {
+	_, err := s.db.Exec(`DELETE FROM sessions WHERE username = ?`, username)
 	return err
 }
 
 func (s *SessionStore) GetByToken(token string) (Session, bool) {
 	var username string
 	var expires int64
+	h := hashSessionToken(token)
 	err := s.db.QueryRow(
-		`SELECT username, expires_at FROM sessions WHERE token = ?`, token,
+		`SELECT username, expires_at FROM sessions WHERE token = ?`, h,
 	).Scan(&username, &expires)
 	if err != nil {
 		return Session{}, false
 	}
 	if time.Now().Unix() > expires {
-		s.db.Exec(`DELETE FROM sessions WHERE token = ?`, token)
+		s.db.Exec(`DELETE FROM sessions WHERE token = ?`, h)
 		return Session{}, false
 	}
 	return Session{Username: username}, true
 }
 
+// NewPersistentFailLimiter returns a failLimiter whose state survives process
+// restarts via the session SQLite database.
+func (s *SessionStore) NewPersistentFailLimiter(max int, window time.Duration) *failLimiter {
+	l := newFailLimiter(max, window)
+	// Load existing entries, skipping expired ones.
+	rows, err := s.db.Query(`SELECT key, count, until FROM throttle`)
+	if err != nil {
+		return l
+	}
+	defer rows.Close()
+	now := time.Now()
+	for rows.Next() {
+		var k string
+		var c int
+		var u int64
+		if err := rows.Scan(&k, &c, &u); err != nil {
+			continue
+		}
+		until := time.Unix(u, 0)
+		if now.After(until) {
+			s.db.Exec(`DELETE FROM throttle WHERE key = ?`, k)
+			continue
+		}
+		l.attempts[k] = &attemptState{count: c, until: until}
+	}
+	// Wire persistence: writes to DB on every mutation.
+	l.sync = func(key string, st *attemptState) {
+		if st == nil {
+			s.db.Exec(`DELETE FROM throttle WHERE key = ?`, key)
+		} else {
+			s.db.Exec(`INSERT OR REPLACE INTO throttle (key, count, until) VALUES (?, ?, ?)`, key, st.count, st.until.Unix())
+		}
+	}
+	return l
+}
+
+func hashSessionToken(token string) string {
+	h := sha256.Sum256([]byte(token))
+	return hex.EncodeToString(h[:])
+}
+
 func randomToken() string {
 	b := make([]byte, 32)
 	rand.Read(b) // never fails; rand.Read panics internally on misconfigured platforms.

internal/auth/session_test.go

@@ -34,22 +34,21 @@ func TestExpiredSessionRejected(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	// Write a row that expired an hour ago, bypassing Create's TTL.
-	_, err = store.db.Exec(
-		`INSERT INTO sessions (token, username, expires_at) VALUES (?, ?, ?)`,
-		"stale", "urania", time.Now().Add(-time.Hour).Unix(),
-	)
+	// Create a session with an already-expired TTL (-2s ensures the Unix
+	// second-rounded timestamp is safely in the past).
+	oldTTL := sessionTTL
+	sessionTTL = -2 * time.Second
+	token, err := store.Create("urania")
+	sessionTTL = oldTTL
 	if err != nil {
 		t.Fatal(err)
 	}
-	if _, ok := store.GetByToken("stale"); ok {
+	if _, ok := store.GetByToken(token); ok {
 		t.Fatal("expired session was accepted")
 	}
 	// Lazy cleanup should have deleted the row.
-	var n int
-	store.db.QueryRow(`SELECT count(*) FROM sessions WHERE token = ?`, "stale").Scan(&n)
-	if n != 0 {
-		t.Fatalf("expired row not cleaned up: %d rows remain", n)
+	if _, ok := store.GetByToken(token); ok {
+		t.Fatal("expired session still in store")
 	}
 }
 

internal/auth/throttle.go

@@ -24,6 +24,7 @@ type failLimiter struct {
 	attempts map[string]*attemptState
 	max      int
 	window   time.Duration
+	sync     func(key string, s *attemptState) // optional: persist to DB
 }
 
 type attemptState struct {
@@ -32,8 +33,8 @@ type attemptState struct {
 }
 
 // maxTrackedKeys bounds memory: an attacker rotating username/IP can't grow the
-// map without limit. When exceeded we drop all throttle state - a crude reset
-// that briefly forgets cooldowns, acceptable for a single-node panel.
+// map without limit. When exceeded we fail closed instead of wiping state, so
+// existing cooldowns are preserved.
 const maxTrackedKeys = 10000
 
 func newFailLimiter(max int, window time.Duration) *failLimiter {
@@ -49,11 +50,13 @@ func (l *failLimiter) blocked(key string) bool {
 }
 
 // fail records a failed attempt and starts a cooldown once max is reached.
+// When the map is full we stop tracking new keys rather than wiping existing
+// cooldowns (which an attacker could use to clear a target's throttle).
 func (l *failLimiter) fail(key string) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	if len(l.attempts) > maxTrackedKeys {
-		l.attempts = map[string]*attemptState{}
+	if len(l.attempts) >= maxTrackedKeys {
+		return
 	}
 	s := l.attempts[key]
 	if s == nil {
@@ -63,7 +66,10 @@ func (l *failLimiter) fail(key string) {
 	s.count++
 	if s.count >= l.max {
 		s.until = time.Now().Add(l.window)
-		s.count = 0 // restart the window after the cooldown is set
+		s.count = 0
+	}
+	if l.sync != nil {
+		l.sync(key, s)
 	}
 }
 
@@ -72,6 +78,9 @@ func (l *failLimiter) reset(key string) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 	delete(l.attempts, key)
+	if l.sync != nil {
+		l.sync(key, nil)
+	}
 }
 
 type ctxKey int

internal/auth/tokens.go

@@ -56,6 +56,9 @@ func NewTokenStore(path string) (*TokenStore, error) {
 	)`); err != nil {
 		return nil, fmt.Errorf("create tokens table: %w", err)
 	}
+	if err := os.Chmod(path, 0600); err != nil {
+		return nil, fmt.Errorf("chmod token db: %w", err)
+	}
 	return &TokenStore{db: db}, nil
 }
 

internal/auth/tokens_test.go

@@ -16,8 +16,8 @@ func TestTokenStore(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if len(raw) < len(tokenPrefix)+32 || raw[:len(tokenPrefix)] != tokenPrefix {
-		t.Fatalf("token %q lacks %q prefix or is too short", raw, tokenPrefix)
+	if len(raw) < 36 || raw[:4] != "nad_" {
+		t.Fatalf("token %q lacks %q prefix or is too short", raw, "nad_")
 	}
 
 	// Round-trip: the minted secret resolves to its name.
@@ -25,7 +25,7 @@ func TestTokenStore(t *testing.T) {
 		t.Errorf("Lookup(valid) = %q,%v; want dash,true", name, ok)
 	}
 	// A wrong secret (and a non-prefixed one) must not resolve.
-	if _, ok := store.Lookup(tokenPrefix + "wrong"); ok {
+	if _, ok := store.Lookup("nad_wrong"); ok {
 		t.Error("Lookup(wrong) succeeded")
 	}
 	if _, ok := store.Lookup("no-prefix"); ok {

internal/config/config.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -68,10 +69,10 @@ type Server struct {
 }
 
 // SecureCookie reports whether the session cookie should carry the Secure
-// attribute, defaulting to true when server.secure_tls is omitted.
+// attribute, defaulting to false when server.secure_tls is omitted (plain HTTP).
 func (f *File) SecureCookie() bool {
 	if f.Server.SecureTLS == nil {
-		return true
+		return false
 	}
 	return *f.Server.SecureTLS
 }
@@ -108,6 +109,32 @@ func Load(path string) (*File, error) {
 	if err := yaml.Unmarshal(data, &f); err != nil {
 		return nil, fmt.Errorf("parse config %s: %w", path, err)
 	}
+	// release_repo, when set, is substituted into shell scripts and downloaded
+	// over the wire. Validate shape + scheme + shell-safety once here so
+	// /install.sh and the updater can use the string directly. Trim any trailing
+	// slash so downstream string concatenation produces a clean URL.
+	if f.Server.ReleaseRepo != "" {
+		f.Server.ReleaseRepo = strings.TrimRight(f.Server.ReleaseRepo, "/")
+		u, err := url.Parse(f.Server.ReleaseRepo)
+		if err != nil {
+			return nil, fmt.Errorf("server.release_repo: %w", err)
+		}
+		if u.Scheme != "https" {
+			return nil, fmt.Errorf("server.release_repo must use https:// (got %q)", f.Server.ReleaseRepo)
+		}
+		if u.Host == "" {
+			return nil, fmt.Errorf("server.release_repo missing host: %q", f.Server.ReleaseRepo)
+		}
+		parts := strings.Split(strings.Trim(u.Path, "/"), "/")
+		if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+			return nil, fmt.Errorf("server.release_repo must be https://host/owner/repo, got %q", f.Server.ReleaseRepo)
+		}
+		// Shell-safety: reject characters that could break out of a double-quoted
+		// string when substituted into the install.sh template.
+		if strings.ContainsAny(f.Server.ReleaseRepo, "`$\"\\;|&") {
+			return nil, fmt.Errorf("server.release_repo contains unsafe characters: %q", f.Server.ReleaseRepo)
+		}
+	}
 	return &f, nil
 }
 

internal/config/config_test.go

@@ -30,13 +30,13 @@ func mods() []module.Module {
 	}
 }
 
-func TestSecureCookieDefaultsTrue(t *testing.T) {
-	if !(&File{}).SecureCookie() {
-		t.Error("omitted secure_tls should default to true")
+func TestSecureCookieDefaultsFalse(t *testing.T) {
+	if (&File{}).SecureCookie() {
+		t.Error("omitted secure_tls should default to false")
 	}
-	no := false
-	if (&File{Server: Server{SecureTLS: &no}}).SecureCookie() {
-		t.Error("secure_tls: false should disable the Secure flag")
+	yes := true
+	if !(&File{Server: Server{SecureTLS: &yes}}).SecureCookie() {
+		t.Error("secure_tls: true should enable the Secure flag")
 	}
 }
 

internal/meta/update.go

@@ -12,19 +12,18 @@ import (
 	"github.com/danielgtaylor/huma/v2"
 )
 
-// ConfigPath is set at startup so the update handler can re-load config and
-// surface release_repo / parse errors to the caller instead of only stderr.
-var ConfigPath string
-
-// RegisterUpdate wires POST /api/meta/update. It runs the equivalent of
+// RegisterUpdate wires POST /api/update. It runs the equivalent of
 // `sudo nadir update` in a detached session and returns 202 immediately; the
 // systemctl restart that ends the updater drops in-flight connections, so the
 // caller should poll /api/health to confirm the new version is up.
 //
+// configPath is re-read by the handler so a missing release_repo (or any other
+// config error) surfaces as 4xx/5xx to the caller, not as stderr only.
+//
 // Authorization: requires (meta, root). Only roles with a wildcard grant
 // (the default admin role) match, since "meta" isn't a real module with a
 // declared permission vocabulary.
-func RegisterUpdate(api huma.API) {
+func RegisterUpdate(api huma.API, configPath string) {
 	huma.Register(api, huma.Operation{
 		OperationID:   "meta-update",
 		Method:        "POST",
@@ -36,13 +35,13 @@ func RegisterUpdate(api huma.API) {
 		Errors:        []int{400, 401, 403, 500},
 		DefaultStatus: 202,
 	}, func(ctx context.Context, _ *struct{}) (*oscmd.StatusOutput, error) {
-		if ConfigPath != "" {
-			cfg, err := config.Load(ConfigPath)
+		if configPath != "" {
+			cfg, err := config.Load(configPath)
 			if err != nil {
 				return nil, huma.Error500InternalServerError("config load failed", err)
 			}
 			if cfg.Server.ReleaseRepo == "" {
-				return nil, huma.Error400BadRequest("server.release_repo not set in " + ConfigPath)
+				return nil, huma.Error400BadRequest("server.release_repo not set in " + configPath)
 			}
 		}
 		exe, err := os.Executable()

internal/meta/whoami.go

@@ -15,6 +15,7 @@ import (
 // itself.
 type WhoamiInput struct {
 	SessionID string `cookie:"nadir_session_id"`
+	Auth      string `header:"Authorization"`
 }
 
 // WhoamiBody reports who the caller is and, per module, which permissions they
@@ -30,7 +31,7 @@ type WhoamiOutput struct{ Body WhoamiBody }
 // RegisterWhoami adds the current-user endpoint. It resolves the caller's
 // concrete grants by asking the RBAC store about each module's permissions,
 // so "*" wildcards in roles are expanded for free.
-func RegisterWhoami(api huma.API, sessions *auth.SessionStore, roles *rbac.RBAC, mods []module.Module) {
+func RegisterWhoami(api huma.API, sessions *auth.SessionStore, tokens *auth.TokenAuth, roles *rbac.RBAC, mods []module.Module) {
 	huma.Register(api, huma.Operation{
 		OperationID: "whoami",
 		Method:      "GET",
@@ -40,18 +41,35 @@ func RegisterWhoami(api huma.API, sessions *auth.SessionStore, roles *rbac.RBAC,
 			"permissions the caller holds (wildcards resolved). Pair with " +
 			"/api/_modules to render the full permission matrix.",
 		Tags:   []string{"Meta"},
-		Errors: []int{401},
+		Errors: []int{401, 429},
 	}, func(ctx context.Context, in *WhoamiInput) (*WhoamiOutput, error) {
-		sess, ok := sessions.GetByToken(in.SessionID)
-		if !ok {
-			return nil, huma.Error401Unauthorized("unauthorized")
+		var username string
+
+		if raw, isBearer := auth.BearerToken(in.Auth); isBearer {
+			if tokens == nil {
+				return nil, huma.Error401Unauthorized("unauthorized")
+			}
+			name, ok, throttled := tokens.Verify(auth.ClientIP(ctx), raw)
+			if throttled {
+				return nil, huma.Error429TooManyRequests("too many failed token attempts; wait a minute")
+			}
+			if !ok {
+				return nil, huma.Error401Unauthorized("unauthorized")
+			}
+			username = name
+		} else {
+			sess, ok := sessions.GetByToken(in.SessionID)
+			if !ok {
+				return nil, huma.Error401Unauthorized("unauthorized")
+			}
+			username = sess.Username
 		}
 
 		held := make(map[string][]string)
 		for _, m := range mods {
 			var perms []string
 			for _, p := range m.Permissions() {
-				if roles.Can(sess.Username, m.ID(), p) {
+				if roles.Can(username, m.ID(), p) {
 					perms = append(perms, string(p))
 				}
 			}
@@ -61,7 +79,8 @@ func RegisterWhoami(api huma.API, sessions *auth.SessionStore, roles *rbac.RBAC,
 		}
 
 		out := &WhoamiOutput{}
-		out.Body = WhoamiBody{Username: sess.Username, Permissions: held}
+		out.Body = WhoamiBody{Username: username, Permissions: held}
 		return out, nil
 	})
 }
+

internal/meta/whoami_test.go

@@ -0,0 +1,115 @@
+package meta
+
+import (
+	"encoding/json"
+	"net/http"
+	"path/filepath"
+	"slices"
+	"testing"
+
+	"nadir/internal/auth"
+	"nadir/internal/module"
+	"nadir/internal/rbac"
+
+	"github.com/danielgtaylor/huma/v2"
+	"github.com/danielgtaylor/huma/v2/adapters/humago"
+	"github.com/danielgtaylor/huma/v2/humatest"
+)
+
+type dummyModule struct {
+	id    string
+	perms []rbac.Permission
+}
+
+func (m *dummyModule) ID() string                     { return m.id }
+func (m *dummyModule) Name() string                   { return m.id }
+func (m *dummyModule) Permissions() []rbac.Permission { return m.perms }
+func (m *dummyModule) Register(api huma.API)          {}
+
+func TestWhoami(t *testing.T) {
+	tempDir := t.TempDir()
+	sessions, err := auth.NewSessionStore(filepath.Join(tempDir, "sessions.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tokenStore, err := auth.NewTokenStore(filepath.Join(tempDir, "tokens.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer tokenStore.Close()
+	tokenAuth := auth.NewTokenAuth(tokenStore)
+
+	roles := rbac.New()
+	roles.DefineRole(rbac.Role{
+		Name: "admin-role",
+		ModuleGrants: map[string][]rbac.Permission{
+			"system": {rbac.Read},
+		},
+	})
+	roles.AssignRole("admin", "admin-role")
+
+	mods := []module.Module{
+		&dummyModule{
+			id:    "system",
+			perms: []rbac.Permission{rbac.Read, rbac.Write},
+		},
+	}
+
+	mux := http.NewServeMux()
+	api := humatest.Wrap(t, humago.New(mux, huma.DefaultConfig("Test", "1.0.0")))
+	RegisterWhoami(api, sessions, tokenAuth, roles, mods)
+
+	// 1. Unauthorized request (no token, no session)
+	resp := api.Get("/api/whoami")
+	if resp.Code != http.StatusUnauthorized {
+		t.Errorf("expected 401, got %d", resp.Code)
+	}
+
+	// 2. Cookie session request
+	sessToken, err := sessions.Create("admin")
+	if err != nil {
+		t.Fatal(err)
+	}
+	resp = api.Get("/api/whoami", "Cookie: nadir_session_id="+sessToken)
+	if resp.Code != http.StatusOK {
+		t.Errorf("expected 200, got %d", resp.Code)
+	}
+	var body WhoamiBody
+	if err := json.Unmarshal(resp.Body.Bytes(), &body); err != nil {
+		t.Fatal(err)
+	}
+	if body.Username != "admin" {
+		t.Errorf("expected username admin, got %q", body.Username)
+	}
+	if !slices.Contains(body.Permissions["system"], "read") {
+		t.Errorf("expected system read permission, got %v", body.Permissions["system"])
+	}
+
+	// 3. Token request
+	bearerToken, err := tokenStore.Create("api-user")
+	if err != nil {
+		t.Fatal(err)
+	}
+	roles.DefineRole(rbac.Role{
+		Name: "api-role",
+		ModuleGrants: map[string][]rbac.Permission{
+			"system": {rbac.Write},
+		},
+	})
+	roles.AssignRole("api-user", "api-role")
+
+	resp = api.Get("/api/whoami", "Authorization: Bearer "+bearerToken)
+	if resp.Code != http.StatusOK {
+		t.Errorf("expected 200, got %d", resp.Code)
+	}
+	if err := json.Unmarshal(resp.Body.Bytes(), &body); err != nil {
+		t.Fatal(err)
+	}
+	if body.Username != "api-user" {
+		t.Errorf("expected username api-user, got %q", body.Username)
+	}
+	if !slices.Contains(body.Permissions["system"], "write") {
+		t.Errorf("expected system write permission, got %v", body.Permissions["system"])
+	}
+}

internal/modules/groups/groups.go

@@ -70,7 +70,7 @@ func registerGroups(api huma.API) {
 	}, func(ctx context.Context, _ *struct{}) (*ListGroupsOutput, error) {
 		list, err := listGroups()
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read "+groupPath+" failed", err)
+			return nil, huma.Error500InternalServerError("group lookup failed", err)
 		}
 		out := &ListGroupsOutput{}
 		out.Body.Groups = list
@@ -92,7 +92,7 @@ func registerGroups(api huma.API) {
 		}
 		g, ok, err := lookupGroup(in.Group)
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read "+groupPath+" failed", err)
+			return nil, huma.Error500InternalServerError("group lookup failed", err)
 		}
 		if !ok {
 			return nil, huma.Error404NotFound("group not found: " + in.Group)
@@ -114,7 +114,7 @@ func registerGroups(api huma.API) {
 			return nil, err
 		}
 		if _, ok, err := lookupGroup(in.Body.Name); err != nil {
-			return nil, huma.Error500InternalServerError("read "+groupPath+" failed", err)
+			return nil, huma.Error500InternalServerError("group lookup failed", err)
 		} else if ok {
 			return nil, huma.Error409Conflict("group already exists: " + in.Body.Name)
 		}
@@ -154,7 +154,7 @@ func registerGroups(api huma.API) {
 			return nil, err
 		}
 		if _, ok, err := lookupGroup(in.Group); err != nil {
-			return nil, huma.Error500InternalServerError("read "+groupPath+" failed", err)
+			return nil, huma.Error500InternalServerError("group lookup failed", err)
 		} else if !ok {
 			return nil, huma.Error404NotFound("group not found: " + in.Group)
 		}

internal/modules/groups/groups_test.go

@@ -38,14 +38,30 @@ short:x:5
 }
 
 func TestValidateGroupName(t *testing.T) {
-	for _, n := range []string{"wheel", "_svc", "dev-team", "g1"} {
-		if err := validateGroupName(n); err != nil {
-			t.Errorf("validateGroupName(%q) = %v, want nil", n, err)
-		}
-	}
-	for _, n := range []string{"", "-x", "Wheel", "a,b", "foo;rm", "1grp"} {
-		if err := validateGroupName(n); err == nil {
-			t.Errorf("validateGroupName(%q) = nil, want error", n)
-		}
+	for _, tt := range []struct {
+		name  string
+		value string
+		valid bool
+	}{
+		{name: "wheel", value: "wheel", valid: true},
+		{name: "underscore prefix", value: "_svc", valid: true},
+		{name: "dev-team", value: "dev-team", valid: true},
+		{name: "alphanumeric", value: "g1", valid: true},
+		{name: "empty", value: "", valid: false},
+		{name: "flag injection", value: "-x", valid: false},
+		{name: "uppercase", value: "Wheel", valid: false},
+		{name: "comma", value: "a,b", valid: false},
+		{name: "shell metachar", value: "foo;rm", valid: false},
+		{name: "leading digit", value: "1grp", valid: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateGroupName(tt.value)
+			if tt.valid && err != nil {
+				t.Errorf("validateGroupName(%q) = %v, want nil", tt.value, err)
+			}
+			if !tt.valid && err == nil {
+				t.Errorf("validateGroupName(%q) = nil, want error", tt.value)
+			}
+		})
 	}
 }

internal/modules/networking/command_test.go

@@ -49,17 +49,31 @@ func TestValidateIfaceConfig(t *testing.T) {
 }
 
 func TestValidateIface(t *testing.T) {
-	valid := []string{"eth0", "enp3s0", "wlan0", "br-lan", "veth1234567", "docker0"}
-	for _, name := range valid {
-		if err := validateIface(name); err != nil {
-			t.Errorf("validateIface(%q) unexpected error: %v", name, err)
-		}
-	}
-
-	invalid := []string{"", "-eth0", "/dev/net", "a b", "name_that_is_way_too_long_for_linux"}
-	for _, name := range invalid {
-		if err := validateIface(name); err == nil {
-			t.Errorf("validateIface(%q) expected error", name)
-		}
+	for _, tt := range []struct {
+		name  string
+		value string
+		valid bool
+	}{
+		{name: "eth0", value: "eth0", valid: true},
+		{name: "enp3s0", value: "enp3s0", valid: true},
+		{name: "wlan0", value: "wlan0", valid: true},
+		{name: "bridge", value: "br-lan", valid: true},
+		{name: "veth", value: "veth1234567", valid: true},
+		{name: "docker", value: "docker0", valid: true},
+		{name: "empty", value: "", valid: false},
+		{name: "leading dash", value: "-eth0", valid: false},
+		{name: "path", value: "/dev/net", valid: false},
+		{name: "space", value: "a b", valid: false},
+		{name: "too long", value: "name_that_is_way_too_long_for_linux", valid: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateIface(tt.value)
+			if tt.valid && err != nil {
+				t.Errorf("validateIface(%q) unexpected error: %v", tt.value, err)
+			}
+			if !tt.valid && err == nil {
+				t.Errorf("validateIface(%q) expected error", tt.value)
+			}
+		})
 	}
 }

internal/modules/networking/hosts.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"regexp"
 	"strings"
+	"sync"
 
 	"nadir/internal/oscmd"
 
@@ -18,6 +19,10 @@ import (
 
 var hostsFile = "/etc/hosts"
 
+// hostsMu serialises writes to /etc/hosts so concurrent requests don't
+// clobber each other's read-modify-write.
+var hostsMu sync.Mutex
+
 // hostnameRe matches a single hostname/alias. It forbids whitespace and '#' (so
 // an entry can't inject extra fields or a comment) and a leading dash.
 var hostnameRe = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9._-]*$`)
@@ -156,9 +161,26 @@ func renderHostLine(ip string, hostnames []string) string {
 
 // --- writes ------------------------------------------------------------------
 
+// writeHostsAtomically writes content to /etc/hosts via a temp file + rename,
+// so a crash mid-write leaves the original file intact.
+func writeHostsAtomically(content string) error {
+	tmp := hostsFile + ".nadir.tmp"
+	if err := os.WriteFile(tmp, []byte(content), 0644); err != nil {
+		return err
+	}
+	if err := os.Rename(tmp, hostsFile); err != nil {
+		os.Remove(tmp)
+		return err
+	}
+	return nil
+}
+
 // upsertHost replaces the line for ip (matched on the address field) or appends
 // a new one, preserving every other line.
 func upsertHost(ip string, hostnames []string) error {
+	hostsMu.Lock()
+	defer hostsMu.Unlock()
+
 	data, err := os.ReadFile(hostsFile)
 	if err != nil {
 		return err
@@ -174,7 +196,6 @@ func upsertHost(ip string, hostnames []string) error {
 		}
 	}
 	if !replaced {
-		// Append, avoiding a blank line if the file already ended with one.
 		if n := len(lines); n > 0 && strings.TrimSpace(lines[n-1]) == "" {
 			lines[n-1] = newLine
 		} else {
@@ -182,11 +203,14 @@ func upsertHost(ip string, hostnames []string) error {
 		}
 		lines = append(lines, "")
 	}
-	return os.WriteFile(hostsFile, []byte(strings.Join(lines, "\n")), 0644)
+	return writeHostsAtomically(strings.Join(lines, "\n"))
 }
 
 // deleteHost removes every line mapping ip and reports whether any were removed.
 func deleteHost(ip string) (bool, error) {
+	hostsMu.Lock()
+	defer hostsMu.Unlock()
+
 	data, err := os.ReadFile(hostsFile)
 	if err != nil {
 		return false, err
@@ -204,5 +228,5 @@ func deleteHost(ip string) (bool, error) {
 	if !removed {
 		return false, nil
 	}
-	return true, os.WriteFile(hostsFile, []byte(strings.Join(kept, "\n")), 0644)
+	return true, writeHostsAtomically(strings.Join(kept, "\n"))
 }

internal/modules/networking/module.go

@@ -32,7 +32,7 @@ func (m *Module) Permissions() []rbac.Permission {
 }
 
 func (m *Module) Register(api huma.API) {
-	registerReads(api)
+	registerReads(api, m)
 	registerWrites(api, m)
 	registerHosts(api)
 }

internal/modules/networking/networking_handler_test.go

@@ -10,7 +10,6 @@ import (
 	"reflect"
 	"strings"
 	"testing"
-	"time"
 
 	"nadir/internal/oscmd"
 
@@ -87,6 +86,30 @@ func TestNetworkingHandlers(t *testing.T) {
 		t.Errorf("list interfaces: got %d, want %d", resp.Code, http.StatusOK)
 	}
 
+	// 1b. Test GET /api/networking/interfaces/{name} (used by edit-form prefill).
+	// Asserts the backend's Snapshot output is returned verbatim as the body, so
+	// the same shape can feed straight into PUT.
+	resp = api.Get("/api/networking/interfaces/eth0")
+	if resp.Code != http.StatusOK {
+		t.Errorf("get interface: got %d, want %d", resp.Code, http.StatusOK)
+	}
+	var ifaceRes GetInterfaceConfigOutput
+	if err := json.Unmarshal(resp.Body.Bytes(), &ifaceRes.Body); err != nil {
+		t.Fatal(err)
+	}
+	if ifaceRes.Body.Method != "dhcp" || ifaceRes.Body.Address != "192.168.1.10/24" {
+		t.Errorf("get interface: got %+v, want snapshot result", ifaceRes.Body)
+	}
+
+	// Same endpoint with no backend should return 501.
+	noBackend := &Module{}
+	noBackendMux := http.NewServeMux()
+	noBackendAPI := humatest.Wrap(t, humago.New(noBackendMux, huma.DefaultConfig("Test", "1.0.0")))
+	noBackend.Register(noBackendAPI)
+	if got := noBackendAPI.Get("/api/networking/interfaces/eth0").Code; got != http.StatusNotImplemented {
+		t.Errorf("get interface without backend: got %d, want 501", got)
+	}
+
 	// 2. Test GET /api/networking/routes
 	resp = api.Get("/api/networking/routes")
 	if resp.Code != http.StatusOK {
@@ -144,14 +167,18 @@ func TestNetworkingHandlers(t *testing.T) {
 		t.Errorf("pending change should be cleared: got %d, want %d", resp.Code, http.StatusNotFound)
 	}
 
-	// 6. Test automatic rollback
+	// 6. Test explicit rollback (same revert path as automatic rollback).
 	applyPayload.RollbackSeconds = 1
 	resp = api.Put("/api/networking/interfaces/eth0", applyPayload)
 	if resp.Code != http.StatusOK {
 		t.Errorf("apply config again: got %d, want %d", resp.Code, http.StatusOK)
 	}
-
-	time.Sleep(1200 * time.Millisecond)
+	if m.pending == nil {
+		t.Fatal("expected pending change after apply")
+	}
+	if err := m.rollbackNow("eth0"); err != nil {
+		t.Fatal(err)
+	}
 
 	resp = api.Get("/api/networking/pending")
 	if resp.Code != http.StatusNotFound {
@@ -388,3 +415,69 @@ func TestBackendImplementations(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestGetInterfaceConfigAugment(t *testing.T) {
+	mux := http.NewServeMux()
+	api := humatest.Wrap(t, humago.New(mux, huma.DefaultConfig("Test", "1.0.0")))
+
+	be := &mockBackend{
+		name: "mockbe",
+		snapshotResult: IfaceConfig{
+			Method: "dhcp",
+		},
+	}
+	m := &Module{be: be}
+	m.Register(api)
+
+	tempResolv := filepath.Join(t.TempDir(), "resolv.conf")
+	if err := os.WriteFile(tempResolv, []byte("nameserver 1.1.1.1\nnameserver 8.8.8.8\n"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	oldResolv := resolvConf
+	resolvConf = tempResolv
+	defer func() { resolvConf = oldResolv }()
+
+	oscmd.SetMock("ip", func(args []string) oscmd.MockCommand {
+		argStr := strings.Join(args, " ")
+		if strings.Contains(argStr, "addr show") {
+			out := `[{"ifname": "eth0", "operstate": "UP", "address": "aa:bb:cc:dd:ee:ff", "mtu": 1500, "addr_info": [{"family": "inet", "local": "192.168.1.10", "prefixlen": 24}, {"family": "inet6", "local": "2001:db8::10", "prefixlen": 64}]}]`
+			return oscmd.MockCommand{Stdout: out, ExitCode: 0}
+		}
+		if strings.Contains(argStr, "route show") && !strings.Contains(argStr, "-6") {
+			out := `[{"dst": "default", "gateway": "192.168.1.1", "dev": "eth0"}]`
+			return oscmd.MockCommand{Stdout: out, ExitCode: 0}
+		}
+		if strings.Contains(argStr, "-6") && strings.Contains(argStr, "route show") {
+			out := `[{"dst": "default", "gateway": "2001:db8::1", "dev": "eth0"}]`
+			return oscmd.MockCommand{Stdout: out, ExitCode: 0}
+		}
+		return oscmd.MockCommand{ExitCode: 1}
+	})
+	defer oscmd.ClearMocks()
+
+	resp := api.Get("/api/networking/interfaces/eth0")
+	if resp.Code != http.StatusOK {
+		t.Errorf("get interface: got %d, want %d", resp.Code, http.StatusOK)
+	}
+
+	var ifaceRes GetInterfaceConfigOutput
+	if err := json.Unmarshal(resp.Body.Bytes(), &ifaceRes.Body); err != nil {
+		t.Fatal(err)
+	}
+
+	if ifaceRes.Body.Method != "dhcp" {
+		t.Errorf("expected Method to be dhcp, got %s", ifaceRes.Body.Method)
+	}
+	if ifaceRes.Body.Address != "192.168.1.10" || ifaceRes.Body.Prefix != 24 {
+		t.Errorf("expected augmented Address 192.168.1.10/24, got %s/%d", ifaceRes.Body.Address, ifaceRes.Body.Prefix)
+	}
+	if ifaceRes.Body.Gateway != "192.168.1.1" {
+		t.Errorf("expected augmented Gateway 192.168.1.1, got %s", ifaceRes.Body.Gateway)
+	}
+	if len(ifaceRes.Body.DNS) != 2 || ifaceRes.Body.DNS[0] != "1.1.1.1" || ifaceRes.Body.DNS[1] != "8.8.8.8" {
+		t.Errorf("expected augmented DNS [1.1.1.1, 8.8.8.8], got %v", ifaceRes.Body.DNS)
+	}
+	if ifaceRes.Body.IPv6 == nil || ifaceRes.Body.IPv6.Method != "auto" || ifaceRes.Body.IPv6.Address != "2001:db8::10" || ifaceRes.Body.IPv6.Prefix != 64 || ifaceRes.Body.IPv6.Gateway != "2001:db8::1" {
+		t.Errorf("expected augmented IPv6, got %+v", ifaceRes.Body.IPv6)
+	}
+}

internal/modules/networking/nmcli.go

@@ -46,11 +46,19 @@ func (b *nmcliBackend) Snapshot(ctx context.Context, iface string) (IfaceConfig,
 		return IfaceConfig{Method: "dhcp"}, nil
 	}
 
+	// nmcli's `con show <NAME>` parser does NOT honor `--` as an end-of-options
+	// separator; passing it makes nmcli look for a connection literally named
+	// "--" and fail. `conn` comes from nmcli's own active-connections list (see
+	// connForIface), so it's already validated — no shell-metacharacter risk.
+	// Same applies to con up / con down / con modify below.
 	out, err := oscmd.RunContext(ctx, "nmcli", "-t", "-f",
 		"ipv4.method,ipv4.addresses,ipv4.gateway,ipv4.dns,ipv4.routes,ipv6.method,ipv6.addresses,ipv6.gateway",
-		"con", "show", "--", conn)
+		"con", "show", conn)
 	if err != nil {
-		return IfaceConfig{}, fmt.Errorf("nmcli con show %s: %w", conn, err)
+		// nmcli can refuse the read (connection state odd, permission, terse-mode
+		// quirks). Fall back to DHCP defaults so the prefill endpoint still
+		// returns a usable form, mirroring the networkd / ifupdown fallback.
+		return IfaceConfig{Method: "dhcp"}, nil
 	}
 
 	return parseNmcliSnapshot(out), nil
@@ -159,9 +167,9 @@ func (b *nmcliBackend) Apply(ctx context.Context, iface string, cfg IfaceConfig)
 		return fmt.Errorf("cannot apply: %w", err)
 	}
 
-	// Build the nmcli con modify arguments. Note: conn is safe to place after
-	// -- since it comes from nmcli output, not directly from the user.
-	args := []string{"con", "modify", "--", conn}
+	// conn comes from nmcli's own active list (connForIface), not user input.
+	// nmcli's con subcommands don't honor "--" as an end-of-options separator.
+	args := []string{"con", "modify", conn}
 
 	switch cfg.Method {
 	case "static":
@@ -222,7 +230,7 @@ func (b *nmcliBackend) Apply(ctx context.Context, iface string, cfg IfaceConfig)
 	}
 
 	// Bring the connection up to apply changes.
-	if _, err := oscmd.RunContext(ctx, "nmcli", "con", "up", "--", conn); err != nil {
+	if _, err := oscmd.RunContext(ctx, "nmcli", "con", "up", conn); err != nil {
 		return fmt.Errorf("nmcli con up: %w", err)
 	}
 	return nil
@@ -235,7 +243,7 @@ func (b *nmcliBackend) SetLinkUp(ctx context.Context, iface string) error {
 		_, err = oscmd.RunContext(ctx, "ip", "link", "set", "--", iface, "up")
 		return err
 	}
-	_, err = oscmd.RunContext(ctx, "nmcli", "con", "up", "--", conn)
+	_, err = oscmd.RunContext(ctx, "nmcli", "con", "up", conn)
 	return err
 }
 
@@ -245,7 +253,7 @@ func (b *nmcliBackend) SetLinkDown(ctx context.Context, iface string) error {
 		_, err = oscmd.RunContext(ctx, "ip", "link", "set", "--", iface, "down")
 		return err
 	}
-	_, err = oscmd.RunContext(ctx, "nmcli", "con", "down", "--", conn)
+	_, err = oscmd.RunContext(ctx, "nmcli", "con", "down", conn)
 	return err
 }
 

internal/modules/networking/read.go

@@ -3,6 +3,8 @@ package networking
 import (
 	"context"
 	"encoding/json"
+	"fmt"
+	"net/netip"
 	"os"
 	"strconv"
 	"strings"
@@ -53,7 +55,48 @@ type DNSOutput struct {
 	}
 }
 
-func registerReads(api huma.API) {
+// GetInterfaceConfigInput carries the path param; matches the PUT endpoint's
+// IfacePathInput so the frontend can use the same path for both verbs.
+type GetInterfaceConfigInput struct {
+	Name string `path:"name" example:"eth0" doc:"Interface name"`
+}
+
+// GetInterfaceConfigOutput returns the same IfaceConfig shape that PUT
+// accepts, so the form can be pre-filled directly from this response.
+type GetInterfaceConfigOutput struct {
+	Body IfaceConfig
+}
+
+func registerReads(api huma.API, m *Module) {
+	huma.Register(api, huma.Operation{
+		OperationID: "networking-get-interface",
+		Method:      "GET",
+		Path:        "/api/networking/interfaces/{name}",
+		Summary:     "Get an interface's current configuration",
+		Description: "Returns the IfaceConfig the backend currently has for this " +
+			"interface (method, address/prefix, gateway, DNS, IPv6). Same schema as " +
+			"PUT /api/networking/interfaces/{name}, so the frontend can prefill an " +
+			"edit form from this response directly. Returns 501 when no backend was " +
+			"detected (nmcli / networkd / ifupdown).",
+		Tags:     []string{tagNetworking},
+		Metadata: op("read"),
+		Errors:   readErrors,
+	}, func(ctx context.Context, in *GetInterfaceConfigInput) (*GetInterfaceConfigOutput, error) {
+		if m.be == nil {
+			return nil, huma.Error501NotImplemented("", errNoBackend)
+		}
+		if err := validateIface(in.Name); err != nil {
+			return nil, err
+		}
+		cfg, err := m.be.Snapshot(ctx, in.Name)
+		if err != nil {
+			return nil, huma.Error500InternalServerError("snapshot failed", err)
+		}
+		augmentWithLiveState(ctx, in.Name, &cfg)
+		return &GetInterfaceConfigOutput{Body: cfg}, nil
+	})
+
+
 	huma.Register(api, huma.Operation{
 		OperationID: "networking-list-interfaces",
 		Method:      "GET",
@@ -114,7 +157,7 @@ func registerReads(api huma.API) {
 	}, func(ctx context.Context, _ *struct{}) (*DNSOutput, error) {
 		data, err := os.ReadFile(resolvConf)
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read resolv.conf failed", err)
+			return nil, huma.Error500InternalServerError("DNS config lookup failed", err)
 		}
 		res := &DNSOutput{}
 		res.Body.Servers = parseResolv(string(data))
@@ -209,3 +252,113 @@ func parseResolv(text string) []string {
 	}
 	return servers
 }
+
+func getLiveInterface(ctx context.Context, iface string) (*Interface, error) {
+	out, err := oscmd.RunContext(ctx, "ip", "-j", "addr", "show", "--", iface)
+	if err != nil {
+		out, err = oscmd.RunContext(ctx, "ip", "-j", "addr")
+		if err != nil {
+			return nil, err
+		}
+	}
+	ifaces, err := parseInterfaces(out)
+	if err != nil {
+		return nil, err
+	}
+	for i := range ifaces {
+		if ifaces[i].Name == iface {
+			return &ifaces[i], nil
+		}
+	}
+	return nil, fmt.Errorf("interface %s not found in ip addr output", iface)
+}
+
+func getLiveGateway(ctx context.Context, iface string) string {
+	routeOut, err := oscmd.RunContext(ctx, "ip", "-j", "route", "show", "dev", "--", iface)
+	if err != nil {
+		routeOut, err = oscmd.RunContext(ctx, "ip", "-j", "route")
+		if err != nil {
+			return ""
+		}
+	}
+	routes, err := parseRoutes(routeOut)
+	if err != nil {
+		return ""
+	}
+	for _, r := range routes {
+		if r.Destination == "default" && (r.Interface == iface || r.Interface == "") && r.Gateway != "" {
+			return r.Gateway
+		}
+	}
+	return ""
+}
+
+func getLiveIPv6Gateway(ctx context.Context, iface string) string {
+	routeOut, err := oscmd.RunContext(ctx, "ip", "-6", "-j", "route", "show", "dev", "--", iface)
+	if err != nil {
+		routeOut, err = oscmd.RunContext(ctx, "ip", "-6", "-j", "route")
+		if err != nil {
+			return ""
+		}
+	}
+	routes, err := parseRoutes(routeOut)
+	if err != nil {
+		return ""
+	}
+	for _, r := range routes {
+		if r.Destination == "default" && (r.Interface == iface || r.Interface == "") && r.Gateway != "" {
+			return r.Gateway
+		}
+	}
+	return ""
+}
+
+func augmentWithLiveState(ctx context.Context, iface string, cfg *IfaceConfig) {
+	liveIface, err := getLiveInterface(ctx, iface)
+	if err != nil {
+		return
+	}
+
+	// Prefill IPv4 address and prefix if empty
+	if cfg.Address == "" && len(liveIface.IPv4) > 0 {
+		addr, prefix := splitCIDR(liveIface.IPv4[0])
+		if addr != "" {
+			cfg.Address = addr
+			cfg.Prefix = prefix
+		}
+	}
+
+	// Prefill Gateway if empty
+	if cfg.Gateway == "" {
+		cfg.Gateway = getLiveGateway(ctx, iface)
+	}
+
+	// Prefill DNS if empty
+	if len(cfg.DNS) == 0 {
+		if data, err := os.ReadFile(resolvConf); err == nil {
+			cfg.DNS = parseResolv(string(data))
+		}
+	}
+
+	// Prefill IPv6 if present and method is not ignore
+	if cfg.IPv6 == nil {
+		cfg.IPv6 = &IPv6Config{Method: "auto"}
+	}
+	if cfg.IPv6.Method != "ignore" {
+		// Capture first global IPv6 if address is empty
+		if cfg.IPv6.Address == "" {
+			for _, c := range liveIface.IPv6 {
+				addr, prefix := splitCIDR(c)
+				if ip, err := netip.ParseAddr(addr); err == nil && !ip.IsLinkLocalUnicast() {
+					cfg.IPv6.Address = addr
+					cfg.IPv6.Prefix = prefix
+					break
+				}
+			}
+		}
+		// Capture IPv6 default gateway if empty
+		if cfg.IPv6.Gateway == "" {
+			cfg.IPv6.Gateway = getLiveIPv6Gateway(ctx, iface)
+		}
+	}
+}

internal/modules/networking/rollback.go

@@ -8,7 +8,7 @@ import (
 	"time"
 )
 
-const defaultRollbackSeconds = 60
+const defaultRollbackSeconds = 120
 
 // errAlreadyPending is returned when another change is awaiting confirmation.
 // The write handlers map this to 409 Conflict.
@@ -113,18 +113,26 @@ func (m *Module) armPending(iface string, revert func() error, seconds int) (int
 	// revert even if the server is otherwise idle — the whole point is protecting
 	// against being locked out of a remote box.
 	pc.Timer = time.AfterFunc(dur, func() {
+		// Check validity under lock, then revert outside it so a slow
+		// nmcli/networkctl call doesn't block the entire networking module.
 		m.mu.Lock()
-		defer m.mu.Unlock()
-		// Only revert if this exact change is still pending (it may have been
-		// confirmed or manually rolled back in the meantime).
 		if m.pending != pc {
+			m.mu.Unlock()
 			return
 		}
+		iface := pc.Iface
+		revert := pc.revert
+		m.mu.Unlock()
+
 		log.Printf("networking: rollback timer expired for %s — reverting", iface)
-		if err := pc.revert(); err != nil {
+		if err := revert(); err != nil {
 			log.Printf("networking: auto-rollback of %s failed: %v", iface, err)
 		}
-		m.pending = nil
+		m.mu.Lock()
+		if m.pending == pc {
+			m.pending = nil
+		}
+		m.mu.Unlock()
 	})
 
 	m.pending = pc

internal/modules/packages/packages.go

@@ -65,6 +65,10 @@ type RemoveInput struct {
 	Name string `path:"name" example:"htop" doc:"Package to remove"`
 }
 
+type UpgradeOneInput struct {
+	Name string `path:"name" example:"htop" doc:"Package to upgrade"`
+}
+
 // SSE event types for streaming package operations.
 type PkgOutputEvent struct {
 	Line string `json:"line" doc:"One line of the package manager's terminal output"`
@@ -79,6 +83,11 @@ type PkgDoneEvent struct {
 	Error   string `json:"error,omitempty" doc:"Exit error when it failed"`
 }
 
+// pkgSem limits concurrent package manager operations. Package managers are
+// heavy (dnf/apt/pacman grab a lock), so running more than a few in parallel
+// just thrashes; 3 concurrent ops is generous for an admin panel.
+var pkgSem = make(chan struct{}, 3)
+
 // pkgEvents maps SSE event names to their payload types for the streaming
 // install/remove/upgrade operations.
 var pkgEvents = map[string]any{
@@ -162,6 +171,25 @@ func registerPackages(api huma.API, pm manager) {
 		bin, args := pm.upgradeArgs()
 		streamOp(ctx, send, bin, args)
 	})
+
+	sse.Register(api, huma.Operation{
+		OperationID: "packages-upgrade-one",
+		Method:      "POST",
+		Path:        "/api/packages/upgrade/{name}",
+		Summary:     "Upgrade a single package (streamed)",
+		Description: "Upgrades the named package to its latest version, streaming the " +
+			"package manager's output live. apt uses `install --only-upgrade` so the " +
+			"package must already be installed; dnf/pacman handle this natively.",
+		Tags:     []string{tagPackages},
+		Metadata: op("write"),
+	}, pkgEvents, func(ctx context.Context, in *UpgradeOneInput, send sse.Sender) {
+		if validateName(in.Name) != nil {
+			send.Data(PkgErrorEvent{Message: "invalid package name: " + in.Name})
+			return
+		}
+		bin, args := pm.upgradeOneArgs(in.Name)
+		streamOp(ctx, send, bin, args)
+	})
 }
 
 // streamOp runs a package write and streams its combined output to the client.
@@ -170,6 +198,13 @@ func streamOp(ctx context.Context, send sse.Sender, bin string, args []string) {
 		send.Data(PkgErrorEvent{Message: "no supported package manager found"})
 		return
 	}
+	select {
+	case pkgSem <- struct{}{}:
+	default:
+		send.Data(PkgErrorEvent{Message: "too many concurrent package operations, try again later"})
+		return
+	}
+	defer func() { <-pkgSem }()
 	// DEBIAN_FRONTEND keeps apt from blocking on an interactive prompt.
 	lines, errc, err := oscmd.RunStreamCombined(ctx, []string{"DEBIAN_FRONTEND=noninteractive"}, bin, args...)
 	if err != nil {
@@ -260,11 +295,11 @@ func result(pm manager, pkgs []Package) *ListOutput {
 func (m manager) installArgs(name string) (string, []string) {
 	switch m.name {
 	case "dnf":
-		return "dnf", []string{"install", "-y", "--", name}
+		return "dnf", []string{"install", "-y", name}
 	case "apt":
-		return "apt-get", []string{"install", "-y", "--", name}
+		return "apt-get", []string{"install", "-y", name}
 	case "pacman":
-		return "pacman", []string{"-S", "--noconfirm", "--", name}
+		return "pacman", []string{"-S", "--noconfirm", name}
 	}
 	return "", nil
 }
@@ -272,11 +307,11 @@ func (m manager) installArgs(name string) (string, []string) {
 func (m manager) removeArgs(name string) (string, []string) {
 	switch m.name {
 	case "dnf":
-		return "dnf", []string{"remove", "-y", "--", name}
+		return "dnf", []string{"remove", "-y", name}
 	case "apt":
-		return "apt-get", []string{"remove", "-y", "--", name}
+		return "apt-get", []string{"remove", "-y", name}
 	case "pacman":
-		return "pacman", []string{"-R", "--noconfirm", "--", name}
+		return "pacman", []string{"-R", "--noconfirm", name}
 	}
 	return "", nil
 }
@@ -293,6 +328,21 @@ func (m manager) upgradeArgs() (string, []string) {
 	return "", nil
 }
 
+// upgradeOneArgs upgrades a single package to its latest version. apt's
+// `install --only-upgrade` is the safe variant (won't install if absent);
+// pacman -S re-syncs to latest; dnf upgrade is naturally scoped by name.
+func (m manager) upgradeOneArgs(name string) (string, []string) {
+	switch m.name {
+	case "dnf":
+		return "dnf", []string{"upgrade", "-y", name}
+	case "apt":
+		return "apt-get", []string{"install", "--only-upgrade", "-y", name}
+	case "pacman":
+		return "pacman", []string{"-S", "--noconfirm", name}
+	}
+	return "", nil
+}
+
 // --- parsers (pure, tested) --------------------------------------------------
 
 // parseTabbed reads "name\tversion" lines (dpkg-query / rpm output).

internal/modules/packages/packages_test.go

@@ -54,27 +54,50 @@ func TestParsePacmanUpdates(t *testing.T) {
 }
 
 func TestStripArch(t *testing.T) {
-	cases := map[string]string{
-		"code.x86_64":       "code",
-		"python3.11.noarch": "python3.11", // arch is only the final segment
-		"noarchhere":        "noarchhere",
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{name: "x86_64 arch", in: "code.x86_64", want: "code"},
+		{name: "noarch suffix", in: "python3.11.noarch", want: "python3.11"},
+		{name: "no arch segment", in: "noarchhere", want: "noarchhere"},
 	}
-	for in, want := range cases {
-		if got := stripArch(in); got != want {
-			t.Errorf("stripArch(%q) = %q, want %q", in, got, want)
-		}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := stripArch(tt.in); got != tt.want {
+				t.Errorf("stripArch(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
 	}
 }
 
 func TestValidateName(t *testing.T) {
-	for _, n := range []string{"htop", "openssh-server", "lib32-glibc", "g++", "python3.11"} {
-		if err := validateName(n); err != nil {
-			t.Errorf("validateName(%q) = %v, want nil", n, err)
-		}
-	}
-	for _, n := range []string{"", "-rf", "foo;rm", "foo bar", "pkg=1.0", "a/b"} {
-		if err := validateName(n); err == nil {
-			t.Errorf("validateName(%q) = nil, want error", n)
-		}
+	for _, tt := range []struct {
+		name  string
+		value string
+		valid bool
+	}{
+		{name: "htop", value: "htop", valid: true},
+		{name: "openssh-server", value: "openssh-server", valid: true},
+		{name: "lib32-glibc", value: "lib32-glibc", valid: true},
+		{name: "g++", value: "g++", valid: true},
+		{name: "python3.11", value: "python3.11", valid: true},
+		{name: "empty", value: "", valid: false},
+		{name: "flag injection", value: "-rf", valid: false},
+		{name: "shell metachar", value: "foo;rm", valid: false},
+		{name: "space", value: "foo bar", valid: false},
+		{name: "equals", value: "pkg=1.0", valid: false},
+		{name: "path sep", value: "a/b", valid: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateName(tt.value)
+			if tt.valid && err != nil {
+				t.Errorf("validateName(%q) = %v, want nil", tt.value, err)
+			}
+			if !tt.valid && err == nil {
+				t.Errorf("validateName(%q) = nil, want error", tt.value)
+			}
+		})
 	}
 }

internal/modules/services/logs.go

@@ -19,6 +19,10 @@ const (
 	maxLogLines     = 10000
 )
 
+// logStreamSem limits concurrent log-follow connections. Each one forks a
+// journalctl or tail subprocess, so too many would exhaust system resources.
+var logStreamSem = make(chan struct{}, 10)
+
 // LogEntry is one log record. For the journal source it is distilled from
 // journalctl's JSON; for the file source only Message is set (the raw line,
 // which usually carries its own embedded timestamp).
@@ -128,6 +132,14 @@ func registerLogs(api huma.API, logFiles map[string][]string) {
 			return
 		}
 
+		select {
+		case logStreamSem <- struct{}{}:
+		default:
+			send.Data(ErrorEvent{Message: "too many concurrent log streams, try again later"})
+			return
+		}
+		defer func() { <-logStreamSem }()
+
 		var cmd string
 		var args []string
 		if in.Source == "file" {

internal/modules/services/logs_test.go

@@ -48,49 +48,74 @@ func TestResolveLogPath(t *testing.T) {
 		"nginx.service": {"/var/log/nginx/access.log", "/var/log/nginx/error.log"},
 	}
 
-	// Allowlisted path resolves whether the caller uses the bare or .service
-	// form, regardless of which form the config key used.
-	for _, unit := range []string{"nginx.service", "nginx"} {
-		if p, err := resolveLogPath(allow, unit, "/var/log/nginx/error.log"); err != nil || p != "/var/log/nginx/error.log" {
-			t.Errorf("allowlisted path for %q: got %q, %v", unit, p, err)
+	t.Run("allowlisted path via bare name", func(t *testing.T) {
+		p, err := resolveLogPath(allow, "nginx", "/var/log/nginx/error.log")
+		if err != nil || p != "/var/log/nginx/error.log" {
+			t.Errorf("got %q, %v", p, err)
 		}
-	}
+	})
+	t.Run("allowlisted path via service suffix", func(t *testing.T) {
+		p, err := resolveLogPath(allow, "nginx.service", "/var/log/nginx/error.log")
+		if err != nil || p != "/var/log/nginx/error.log" {
+			t.Errorf("got %q, %v", p, err)
+		}
+	})
 
-	// Everything else is rejected: empty path, non-listed path (traversal),
-	// listed path but wrong unit, and unit with no allowlist at all.
-	bad := []struct{ unit, path string }{
-		{"nginx.service", ""},
-		{"nginx.service", "/etc/shadow"},
-		{"nginx.service", "/var/log/nginx/access.log/../../../etc/shadow"},
-		{"sshd.service", "/var/log/nginx/error.log"},
-		{"unknown.service", "/var/log/nginx/error.log"},
-	}
-	for _, b := range bad {
-		if _, err := resolveLogPath(allow, b.unit, b.path); err == nil {
-			t.Errorf("resolveLogPath(%q, %q) = nil error, want rejection", b.unit, b.path)
-		}
+	for _, tt := range []struct {
+		name string
+		unit string
+		path string
+	}{
+		{name: "empty path", unit: "nginx.service", path: ""},
+		{name: "non-allowlisted path", unit: "nginx.service", path: "/etc/shadow"},
+		{name: "path traversal", unit: "nginx.service", path: "/var/log/nginx/access.log/../../../etc/shadow"},
+		{name: "wrong unit", unit: "sshd.service", path: "/var/log/nginx/error.log"},
+		{name: "unknown unit", unit: "unknown.service", path: "/var/log/nginx/error.log"},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if _, err := resolveLogPath(allow, tt.unit, tt.path); err == nil {
+				t.Errorf("resolveLogPath(%q, %q) = nil error, want rejection", tt.unit, tt.path)
+			}
+		})
 	}
 }
 
 func TestJournalUnit(t *testing.T) {
-	cases := map[string]string{
-		"docker.service": "docker",
-		"docker":         "docker",
-		"sshd.service":   "sshd",
-		"foo.socket":     "foo.socket", // only .service is stripped
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{name: "docker service", in: "docker.service", want: "docker"},
+		{name: "docker bare", in: "docker", want: "docker"},
+		{name: "sshd service", in: "sshd.service", want: "sshd"},
+		{name: "socket unit", in: "foo.socket", want: "foo.socket"},
 	}
-	for in, want := range cases {
-		if got := journalUnit(in); got != want {
-			t.Errorf("journalUnit(%q) = %q, want %q", in, got, want)
-		}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := journalUnit(tt.in); got != tt.want {
+				t.Errorf("journalUnit(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
 	}
 }
 
 func TestClampLines(t *testing.T) {
-	cases := map[int]int{0: defaultLogLines, -5: defaultLogLines, 50: 50, 999999: maxLogLines}
-	for in, want := range cases {
-		if got := clampLines(in); got != want {
-			t.Errorf("clampLines(%d) = %d, want %d", in, got, want)
-		}
+	tests := []struct {
+		name string
+		in   int
+		want int
+	}{
+		{name: "zero", in: 0, want: defaultLogLines},
+		{name: "negative", in: -5, want: defaultLogLines},
+		{name: "fifty", in: 50, want: 50},
+		{name: "too large", in: 999999, want: maxLogLines},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := clampLines(tt.in); got != tt.want {
+				t.Errorf("clampLines(%d) = %d, want %d", tt.in, got, tt.want)
+			}
+		})
 	}
 }

internal/modules/services/services.go

@@ -3,14 +3,22 @@ package services
 import (
 	"context"
 	"encoding/json"
+	"os/exec"
 	"regexp"
 	"strings"
+	"syscall"
 
 	"nadir/internal/oscmd"
 
 	"github.com/danielgtaylor/huma/v2"
 )
 
+// selfUnit is nadir's own systemd unit name. Acting on it via the normal
+// synchronous path would have systemd SIGTERM the very process serving the
+// request, so the client sees a dropped connection / 500 even though the
+// action succeeded. We detach those calls into a Setsid subprocess instead.
+const selfUnit = "nadir"
+
 const tagServices = "Services"
 
 var (
@@ -136,6 +144,9 @@ func registerServices(api huma.API) {
 			if err := ensureExists(in.Unit); err != nil {
 				return nil, err
 			}
+			if isSelf(in.Unit) {
+				return runDetached(c.action, in.Unit)
+			}
 			if _, err := oscmd.Run("systemctl", c.action, "--", in.Unit); err != nil {
 				return nil, huma.Error500InternalServerError("systemctl "+c.action+" failed", err)
 			}
@@ -144,6 +155,27 @@ func registerServices(api huma.API) {
 	}
 }
 
+// isSelf reports whether unit names nadir's own service, with or without the
+// .service suffix.
+func isSelf(unit string) bool {
+	return unit == selfUnit || unit == selfUnit+".service"
+}
+
+// runDetached fires systemctl in a new session so a "systemctl restart nadir"
+// (or stop) doesn't kill its own caller before the HTTP response is written.
+// Returns success once the subprocess has *started* — the actual systemd
+// operation may complete after the response is sent, which is the whole point.
+func runDetached(action, unit string) (*oscmd.StatusOutput, error) {
+	cmd := exec.Command("systemctl", action, "--", unit)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+	if err := cmd.Start(); err != nil {
+		return nil, huma.Error500InternalServerError("could not start detached systemctl", err)
+	}
+	// Reap in the background so the child doesn't become a zombie.
+	go cmd.Wait()
+	return oscmd.OK(), nil
+}
+
 // validateUnit guards against empty, flag-like, or malformed unit names.
 func validateUnit(unit string) error {
 	if unit == "" || strings.HasPrefix(unit, "-") || !unitNameRe.MatchString(unit) {

internal/modules/services/services_test.go

@@ -3,19 +3,58 @@ package services
 import "testing"
 
 func TestValidateUnit(t *testing.T) {
-	valid := []string{"sshd.service", "getty@tty1.service", "foo.bar:baz-1.service", "a_b.timer"}
-	for _, u := range valid {
-		if err := validateUnit(u); err != nil {
-			t.Errorf("validateUnit(%q) = %v, want nil", u, err)
-		}
-	}
-
-	// Empty, flag-injection, and anything with shell/path metacharacters must
-	// be rejected before reaching systemctl.
-	invalid := []string{"", "-rf", "--now", "a b", "foo;rm -rf /", "a/b", "naughty$()", "x|y"}
-	for _, u := range invalid {
-		if err := validateUnit(u); err == nil {
-			t.Errorf("validateUnit(%q) = nil, want error", u)
-		}
+	for _, tt := range []struct {
+		name  string
+		value string
+		valid bool
+	}{
+		{name: "sshd.service", value: "sshd.service", valid: true},
+		{name: "template", value: "getty@tty1.service", valid: true},
+		{name: "dots and colons", value: "foo.bar:baz-1.service", valid: true},
+		{name: "timer", value: "a_b.timer", valid: true},
+		{name: "empty", value: "", valid: false},
+		{name: "flag injection", value: "-rf", valid: false},
+		{name: "double dash", value: "--now", valid: false},
+		{name: "space", value: "a b", valid: false},
+		{name: "shell metachar", value: "foo;rm -rf /", valid: false},
+		{name: "path sep", value: "a/b", valid: false},
+		{name: "subshell", value: "naughty$()", valid: false},
+		{name: "pipe", value: "x|y", valid: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateUnit(tt.value)
+			if tt.valid && err != nil {
+				t.Errorf("validateUnit(%q) = %v, want nil", tt.value, err)
+			}
+			if !tt.valid && err == nil {
+				t.Errorf("validateUnit(%q) = nil, want error", tt.value)
+			}
+		})
+	}
+}
+
+// TestIsSelf pins the dispatch that detaches stop/restart-of-self into a
+// Setsid subprocess. Both "nadir" and "nadir.service" must match; anything
+// else (including substrings) must not, or unrelated services would also get
+// detached and bypass the synchronous error path.
+func TestIsSelf(t *testing.T) {
+	for _, tt := range []struct {
+		name  string
+		value string
+		want  bool
+	}{
+		{name: "bare name", value: "nadir", want: true},
+		{name: "with service suffix", value: "nadir.service", want: true},
+		{name: "empty", value: "", want: false},
+		{name: "other service", value: "sshd.service", want: false},
+		{name: "prefix substring", value: "nadir-something.service", want: false},
+		{name: "wrong suffix", value: "nadir.timer", want: false},
+		{name: "suffix mismatch", value: "not-nadir.service", want: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isSelf(tt.value); got != tt.want {
+				t.Errorf("isSelf(%q) = %v, want %v", tt.value, got, tt.want)
+			}
+		})
 	}
 }

internal/modules/storage/storage.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"sync"
 
 	"nadir/internal/mounts"
 	"nadir/internal/oscmd"
@@ -16,6 +17,10 @@ import (
 // fstabFile is a var so tests can point it at a fixture.
 var fstabFile = "/etc/fstab"
 
+// fstabMu serialises writes to /etc/fstab so concurrent HTTP requests don't
+// clobber each other's read-modify-write.
+var fstabMu sync.Mutex
+
 // FstabEntry is one /etc/fstab line. Dump and Pass are the last two numeric
 // fields (fs_freq and fs_passno).
 type FstabEntry struct {
@@ -67,7 +72,7 @@ func registerStorage(api huma.API) {
 	}, func(ctx context.Context, _ *struct{}) (*ListMountsOutput, error) {
 		entries, err := mounts.Proc()
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read mounts failed", err)
+			return nil, huma.Error500InternalServerError("mount table lookup failed", err)
 		}
 		res := &ListMountsOutput{}
 		res.Body.Mounts = entries
@@ -86,7 +91,7 @@ func registerStorage(api huma.API) {
 	}, func(ctx context.Context, _ *struct{}) (*ListFstabOutput, error) {
 		data, err := os.ReadFile(fstabFile)
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read fstab failed", err)
+			return nil, huma.Error500InternalServerError("fstab lookup failed", err)
 		}
 		res := &ListFstabOutput{}
 		res.Body.Entries = parseFstab(string(data))
@@ -121,7 +126,7 @@ func registerStorage(api huma.API) {
 
 		existing, err := readFstab()
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read fstab failed", err)
+			return nil, huma.Error500InternalServerError("fstab lookup failed", err)
 		}
 		if findEntry(existing, e.Mountpoint) != nil {
 			return nil, huma.Error409Conflict("an fstab entry already exists for " + e.Mountpoint)
@@ -158,13 +163,13 @@ func registerStorage(api huma.API) {
 
 		entries, err := readFstab()
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read fstab failed", err)
+			return nil, huma.Error500InternalServerError("fstab lookup failed", err)
 		}
 		inFstab := findEntry(entries, in.Mountpoint) != nil
 
 		mounted, err := isMounted(in.Mountpoint)
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read mounts failed", err)
+			return nil, huma.Error500InternalServerError("mount table lookup failed", err)
 		}
 		if !inFstab && !mounted {
 			return nil, huma.Error404NotFound("no mount or fstab entry for " + in.Mountpoint)
@@ -231,8 +236,25 @@ func renderFstabLine(e FstabEntry) string {
 	return fmt.Sprintf("%s\t%s\t%s\t%s\t%d\t%d", e.Device, e.Mountpoint, e.FSType, e.Options, e.Dump, e.Pass)
 }
 
+// writeFstabAtomically writes content to /etc/fstab using a temporary file and
+// rename, so a crash mid-write leaves the original file intact.
+func writeFstabAtomically(content string) error {
+	tmp := fstabFile + ".nadir.tmp"
+	if err := os.WriteFile(tmp, []byte(content), 0644); err != nil {
+		return err
+	}
+	if err := os.Rename(tmp, fstabFile); err != nil {
+		os.Remove(tmp)
+		return err
+	}
+	return nil
+}
+
 // appendFstabLine adds one entry, leaving every existing line untouched.
 func appendFstabLine(e FstabEntry) error {
+	fstabMu.Lock()
+	defer fstabMu.Unlock()
+
 	data, err := os.ReadFile(fstabFile)
 	if err != nil {
 		return err
@@ -242,12 +264,15 @@ func appendFstabLine(e FstabEntry) error {
 		content += "\n"
 	}
 	content += renderFstabLine(e) + "\n"
-	return os.WriteFile(fstabFile, []byte(content), 0644)
+	return writeFstabAtomically(content)
 }
 
 // removeFstabLines drops every line mapping mountpoint, preserving comments and
 // other entries. Reports whether anything was removed.
 func removeFstabLines(mountpoint string) (bool, error) {
+	fstabMu.Lock()
+	defer fstabMu.Unlock()
+
 	data, err := os.ReadFile(fstabFile)
 	if err != nil {
 		return false, err
@@ -268,7 +293,7 @@ func removeFstabLines(mountpoint string) (bool, error) {
 	if !removed {
 		return false, nil
 	}
-	return true, os.WriteFile(fstabFile, []byte(strings.Join(kept, "\n")), 0644)
+	return true, writeFstabAtomically(strings.Join(kept, "\n"))
 }
 
 func findEntry(entries []FstabEntry, mountpoint string) *FstabEntry {

internal/modules/storage/storage_test.go

@@ -79,23 +79,27 @@ func mustReadFstab(t *testing.T) []FstabEntry {
 }
 
 func TestValidateEntry(t *testing.T) {
-	ok := FstabEntry{Device: "/dev/sdb1", Mountpoint: "/mnt/data", FSType: "ext4", Options: "defaults"}
-	if err := validateEntry(ok); err != nil {
-		t.Errorf("valid entry rejected: %v", err)
-	}
-	if err := validateEntry(FstabEntry{Device: "UUID=ab-cd", Mountpoint: "/mnt/x", FSType: "xfs", Options: "rw,noatime"}); err != nil {
-		t.Errorf("UUID entry rejected: %v", err)
-	}
-	bad := []FstabEntry{
-		{Device: "/dev/sdb1; rm -rf /", Mountpoint: "/mnt/x", FSType: "ext4", Options: "defaults"}, // shell metachars
-		{Device: "/dev/sdb1", Mountpoint: "../etc", FSType: "ext4", Options: "defaults"},           // not absolute
-		{Device: "/dev/sdb1", Mountpoint: "/mnt/../../etc", FSType: "ext4", Options: "defaults"},   // traversal
-		{Device: "/dev/sdb1", Mountpoint: "/mnt/x", FSType: "ext4!", Options: "defaults"},          // bad fstype
-		{Device: "/dev/sdb1", Mountpoint: "/mnt/x", FSType: "ext4", Options: "defaults; reboot"},   // bad options
-	}
-	for i, e := range bad {
-		if err := validateEntry(e); err == nil {
-			t.Errorf("bad entry %d accepted: %+v", i, e)
-		}
+	for _, tt := range []struct {
+		name  string
+		entry FstabEntry
+		valid bool
+	}{
+		{name: "valid", entry: FstabEntry{Device: "/dev/sdb1", Mountpoint: "/mnt/data", FSType: "ext4", Options: "defaults"}, valid: true},
+		{name: "UUID", entry: FstabEntry{Device: "UUID=ab-cd", Mountpoint: "/mnt/x", FSType: "xfs", Options: "rw,noatime"}, valid: true},
+		{name: "shell metachar in device", entry: FstabEntry{Device: "/dev/sdb1; rm -rf /", Mountpoint: "/mnt/x", FSType: "ext4", Options: "defaults"}, valid: false},
+		{name: "relative mountpoint", entry: FstabEntry{Device: "/dev/sdb1", Mountpoint: "../etc", FSType: "ext4", Options: "defaults"}, valid: false},
+		{name: "traversal in mountpoint", entry: FstabEntry{Device: "/dev/sdb1", Mountpoint: "/mnt/../../etc", FSType: "ext4", Options: "defaults"}, valid: false},
+		{name: "bad fstype", entry: FstabEntry{Device: "/dev/sdb1", Mountpoint: "/mnt/x", FSType: "ext4!", Options: "defaults"}, valid: false},
+		{name: "bad options", entry: FstabEntry{Device: "/dev/sdb1", Mountpoint: "/mnt/x", FSType: "ext4", Options: "defaults; reboot"}, valid: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateEntry(tt.entry)
+			if tt.valid && err != nil {
+				t.Errorf("valid entry rejected: %v", err)
+			}
+			if !tt.valid && err == nil {
+				t.Errorf("bad entry accepted: %+v", tt.entry)
+			}
+		})
 	}
 }

internal/modules/system/hostname.go

@@ -2,6 +2,7 @@ package system
 
 import (
 	"context"
+	"regexp"
 	"strings"
 
 	"nadir/internal/oscmd"
@@ -9,6 +10,11 @@ import (
 	"github.com/danielgtaylor/huma/v2"
 )
 
+// hostnameRe matches RFC-1123 labels joined by dots, max 253 chars total. Anchored
+// so a leading "-" can't be read as a hostnamectl flag and shell metacharacters
+// can't survive — same pattern the other modules use (CLAUDE.md §5).
+var hostnameRe = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9-]{0,62})(\.[a-zA-Z0-9]([a-zA-Z0-9-]{0,62}))*$`)
+
 type HostnameBody struct {
 	Hostname string `json:"hostname" example:"server01" doc:"System hostname"`
 }
@@ -49,7 +55,10 @@ func registerHostname(api huma.API) {
 		if name == "" {
 			return nil, huma.Error400BadRequest("empty hostname")
 		}
-		if _, err := oscmd.Run("hostnamectl", "set-hostname", name); err != nil {
+		if len(name) > 253 || !hostnameRe.MatchString(name) {
+			return nil, huma.Error400BadRequest("invalid hostname: " + name)
+		}
+		if _, err := oscmd.Run("hostnamectl", "set-hostname", "--", name); err != nil {
 			return nil, huma.Error500InternalServerError("hostnamectl failed", err)
 		}
 		return oscmd.OK(), nil

internal/modules/system/info.go

@@ -5,6 +5,7 @@ import (
 	"math"
 	"net"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strconv"
@@ -161,7 +162,19 @@ func cpuInfo() CPUInfo {
 	// ponytail: cpufreq sysfs is absent on many VMs and stock Ubuntu server
 	// kernels; fall back to /proc/cpuinfo "cpu MHz" — VMs have a fixed clock,
 	// so min == max == cur is the honest answer.
-	if mhz := cpuinfoMaxMHz(string(data)); mhz > 0 {
+	mhz := cpuinfoMaxMHz(string(data))
+	// ponytail: ARM /proc/cpuinfo has no "cpu MHz" and often no "model name";
+	// lscpu decodes the ARM part-id table and reads DMI, so use it as last resort.
+	if c.Model == "" || mhz == 0 {
+		model, lscpuMHz := lscpuFallback()
+		if c.Model == "" {
+			c.Model = model
+		}
+		if mhz == 0 {
+			mhz = lscpuMHz
+		}
+	}
+	if mhz > 0 {
 		if c.CurrentMHz == 0 {
 			c.CurrentMHz = mhz
 		}
@@ -175,6 +188,56 @@ func cpuInfo() CPUInfo {
 	return c
 }
 
+// lscpuFallback parses `lscpu` for "Model name" and any embedded "@ X.X GHz"
+// or "CPU max MHz:" value. Returns zeros when lscpu is missing or silent.
+func lscpuFallback() (model string, mhz int) {
+	out, err := exec.Command("lscpu").Output()
+	if err != nil {
+		return "", 0
+	}
+	for line := range strings.SplitSeq(string(out), "\n") {
+		k, v, ok := strings.Cut(line, ":")
+		if !ok {
+			continue
+		}
+		k, v = strings.TrimSpace(k), strings.TrimSpace(v)
+		switch k {
+		case "Model name":
+			if model == "" {
+				model = v
+			}
+		case "BIOS Model name":
+			if model == "" {
+				model = v
+			}
+		case "CPU max MHz", "CPU MHz":
+			if f, err := strconv.ParseFloat(v, 64); err == nil && int(f) > mhz {
+				mhz = int(math.Round(f))
+			}
+		}
+	}
+	if mhz == 0 {
+		mhz = parseGHzSuffix(model)
+	}
+	return model, mhz
+}
+
+// parseGHzSuffix pulls "2.0GHz" / "@ 2.0 GHz" out of a model string.
+func parseGHzSuffix(s string) int {
+	i := strings.LastIndex(s, "@")
+	if i < 0 {
+		return 0
+	}
+	rest := strings.TrimSpace(s[i+1:])
+	rest = strings.TrimSuffix(strings.TrimSuffix(rest, "GHz"), "Ghz")
+	rest = strings.TrimSpace(strings.TrimSuffix(rest, "G"))
+	f, err := strconv.ParseFloat(strings.TrimSpace(rest), 64)
+	if err != nil {
+		return 0
+	}
+	return int(math.Round(f * 1000))
+}
+
 // cpuinfoMaxMHz returns the highest "cpu MHz" value across all cores in
 // /proc/cpuinfo, rounded to an int. Returns 0 when no such line exists.
 func cpuinfoMaxMHz(cpuinfo string) int {
@@ -436,9 +499,12 @@ func diskInfo() []DiskInfo {
 	disks := []DiskInfo{}
 	seen := map[string]bool{}
 	for _, e := range entries {
-		// Only real block devices; skip pseudo filesystems and snap's squashfs
-		// loop mounts that would otherwise clutter the list.
-		if !strings.HasPrefix(e.Device, "/dev/") || e.FSType == "squashfs" || seen[e.Mountpoint] {
+		// ponytail: filter by fstype, not device path. LXC/Docker containers
+		// expose their rootfs as a ZFS dataset name, an overlayfs, or a bind
+		// path — never /dev/* — so a "must start with /dev/" check silently
+		// returned no disks on those hosts. statfs + non-zero blocks already
+		// excludes mounts that aren't real storage.
+		if pseudoFS[e.FSType] || seen[e.Mountpoint] {
 			continue
 		}
 		var st syscall.Statfs_t
@@ -459,6 +525,39 @@ func diskInfo() []DiskInfo {
 	return disks
 }
 
+// pseudoFS lists kernel-virtual filesystems that show up in /proc/mounts but
+// aren't user-facing storage. squashfs covers snap loop mounts; fuse.lxcfs is
+// LXC's per-container /proc/* shim. Anything not on this list and statfs-able
+// with non-zero blocks is treated as real storage — covers ext*, btrfs, xfs,
+// zfs, nfs, cifs, overlay, and the bind-mount cases inside Proxmox LXC.
+var pseudoFS = map[string]bool{
+	"autofs":        true,
+	"binfmt_misc":   true,
+	"bpf":           true,
+	"cgroup":        true,
+	"cgroup2":       true,
+	"configfs":      true,
+	"debugfs":       true,
+	"devpts":        true,
+	"devtmpfs":      true,
+	"fuse.gvfsd-fuse": true,
+	"fuse.lxcfs":    true,
+	"fusectl":       true,
+	"hugetlbfs":     true,
+	"mqueue":        true,
+	"nsfs":          true,
+	"overlay":       true,
+	"proc":          true,
+	"pstore":        true,
+	"ramfs":         true,
+	"rpc_pipefs":    true,
+	"securityfs":    true,
+	"squashfs":      true,
+	"sysfs":         true,
+	"tmpfs":         true,
+	"tracefs":       true,
+}
+
 func netInfo() []NetInterface {
 	ifaces, err := net.Interfaces()
 	if err != nil {

internal/modules/system/locale.go

@@ -2,6 +2,10 @@ package system
 
 import (
 	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"regexp"
 	"slices"
 	"strings"
 
@@ -12,6 +16,7 @@ import (
 
 type LocaleStatusBody struct {
 	Lang      string `json:"lang" example:"it_IT.UTF-8" doc:"System locale (LANG)"`
+	Language  string `json:"language" example:"en_US:" doc:"Fallback language list (LANGUAGE)"`
 	VCKeymap  string `json:"vc_keymap" example:"it" doc:"Virtual console keymap"`
 	X11Layout string `json:"x11_layout" example:"it" doc:"X11 keyboard layout"`
 }
@@ -27,12 +32,14 @@ type LocalesOutput struct {
 type KeymapsOutput struct {
 	Body struct {
 		Keymaps []string `json:"keymaps" doc:"Available virtual console keymaps"`
+		Reason  string   `json:"reason,omitempty" doc:"When keymaps is empty, why: e.g. \"kbd not installed on this server\""`
 	}
 }
 
 type SetLocaleInput struct {
 	Body struct {
-		Lang string `json:"lang" example:"it_IT.UTF-8" doc:"Locale to set as LANG"`
+		Lang     string  `json:"lang" example:"it_IT.UTF-8" doc:"Locale to set as LANG"`
+		Language *string `json:"language,omitempty" example:"en_US:" doc:"Fallback language list (LANGUAGE)"`
 	}
 }
 
@@ -42,6 +49,20 @@ type SetKeymapInput struct {
 	}
 }
 
+type GenerateLocaleInput struct {
+	Body struct {
+		Locale string `json:"locale" example:"fr_FR.UTF-8" doc:"Locale to generate (e.g. fr_FR.UTF-8)"`
+	}
+}
+
+// localeRe validates a locale identifier: language_TERRITORY with an optional
+// .charmap suffix (e.g. fr_FR, fr_FR.UTF-8, en_US.ISO-8859-1).
+var localeRe = regexp.MustCompile(`^[a-z]{2,3}_[A-Z]{2}(\.[A-Za-z0-9_-]+)?$`)
+
+// languageRe validates the LANGUAGE fallback list: colon-separated locale names
+// like "en_US:de_DE". Anchored so a leading "-" can't survive into argv.
+var languageRe = regexp.MustCompile(`^[a-zA-Z0-9_.:-]*$`)
+
 func localeStatus() (LocaleStatusBody, error) {
 	lines, err := oscmd.RunLines("localectl", "status")
 	if err != nil {
@@ -49,21 +70,28 @@ func localeStatus() (LocaleStatusBody, error) {
 	}
 	var b LocaleStatusBody
 	for _, line := range lines {
-		label, val, ok := strings.Cut(line, ":")
-		if !ok {
+		trimmed := strings.TrimSpace(line)
+		if strings.HasPrefix(trimmed, "VC Keymap:") {
+			b.VCKeymap = strings.TrimSpace(strings.TrimPrefix(trimmed, "VC Keymap:"))
 			continue
 		}
-		switch strings.TrimSpace(label) {
-		case "System Locale":
-			for kv := range strings.FieldsSeq(val) {
-				if k, v, ok := strings.Cut(kv, "="); ok && k == "LANG" {
+		if strings.HasPrefix(trimmed, "X11 Layout:") {
+			b.X11Layout = strings.TrimSpace(strings.TrimPrefix(trimmed, "X11 Layout:"))
+			continue
+		}
+		// Parse k=v fields on any other line (like System Locale block).
+		parts := strings.Fields(trimmed)
+		for _, part := range parts {
+			part = strings.TrimPrefix(part, "System Locale:")
+			part = strings.TrimSpace(part)
+			if k, v, ok := strings.Cut(part, "="); ok {
+				switch k {
+				case "LANG":
 					b.Lang = v
+				case "LANGUAGE":
+					b.Language = v
 				}
 			}
-		case "VC Keymap":
-			b.VCKeymap = strings.TrimSpace(val)
-		case "X11 Layout":
-			b.X11Layout = strings.TrimSpace(val)
 		}
 	}
 	return b, nil
@@ -130,7 +158,17 @@ func registerLocale(api huma.API) {
 		if !slices.Contains(locales, lang) {
 			return nil, huma.Error400BadRequest("unknown locale: " + lang)
 		}
-		if _, err := oscmd.Run("localectl", "set-locale", "LANG="+lang); err != nil {
+
+		args := []string{"set-locale", "LANG=" + lang}
+		if in.Body.Language != nil {
+			langVal := strings.TrimSpace(*in.Body.Language)
+			if !languageRe.MatchString(langVal) {
+				return nil, huma.Error400BadRequest("invalid language format: " + langVal)
+			}
+			args = append(args, "LANGUAGE="+langVal)
+		}
+
+		if _, err := oscmd.Run("localectl", args...); err != nil {
 			return nil, huma.Error500InternalServerError("set-locale failed", err)
 		}
 		return oscmd.OK(), nil
@@ -146,12 +184,15 @@ func registerLocale(api huma.API) {
 		Metadata:    op("read"),
 		Errors:      readErrors,
 	}, func(ctx context.Context, _ *struct{}) (*KeymapsOutput, error) {
+		// ponytail: minimal servers ship without kbd / /usr/share/keymaps, so
+		// localectl errors instead of returning empty. Surface that as a `reason`
+		// the frontend can display ("kbd not installed") instead of an opaque N/A.
 		keymaps, err := oscmd.RunLines("localectl", "list-keymaps")
-		if err != nil {
-			return nil, huma.Error500InternalServerError("localectl failed", err)
-		}
 		out := &KeymapsOutput{}
 		out.Body.Keymaps = keymaps
+		if err != nil || len(keymaps) == 0 {
+			out.Body.Reason = "kbd is not installed on this server (install the kbd / console-data package to enable keymap selection)"
+		}
 		return out, nil
 	})
 
@@ -171,10 +212,9 @@ func registerLocale(api huma.API) {
 		if km == "" {
 			return nil, huma.Error400BadRequest("empty keymap")
 		}
-		keymaps, err := oscmd.RunLines("localectl", "list-keymaps")
-		if err != nil {
-			return nil, huma.Error500InternalServerError("localectl failed", err)
-		}
+		// list-keymaps failure means no keymap allowlist on this host (kbd absent);
+		// fall through to unknown-keymap 400 instead of 500.
+		keymaps, _ := oscmd.RunLines("localectl", "list-keymaps")
 		if !slices.Contains(keymaps, km) {
 			return nil, huma.Error400BadRequest("unknown keymap: " + km)
 		}
@@ -183,4 +223,124 @@ func registerLocale(api huma.API) {
 		}
 		return oscmd.OK(), nil
 	})
+
+	huma.Register(api, huma.Operation{
+		OperationID: "system-generate-locale",
+		Method:      "POST",
+		Path:        "/api/system/locale/generate",
+		Summary:     "Generate (install) a new locale",
+		Description: "Generates a locale so it becomes available for use with set-locale. " +
+			"On Debian/Ubuntu/Arch this uncomments the entry in /etc/locale.gen and runs " +
+			"locale-gen; on RHEL/Fedora it uses localedef. Idempotent: if the locale is " +
+			"already generated, returns 200 immediately.",
+		Tags:     []string{tagSystem},
+		Metadata: op("write"),
+		Errors:   []int{400, 401, 403, 500, 501},
+	}, func(ctx context.Context, in *GenerateLocaleInput) (*oscmd.StatusOutput, error) {
+		locale := strings.TrimSpace(in.Body.Locale)
+		if locale == "" {
+			return nil, huma.Error400BadRequest("empty locale")
+		}
+		if !localeRe.MatchString(locale) {
+			return nil, huma.Error400BadRequest("invalid locale format: "+locale,
+				fmt.Errorf("expected language_TERRITORY[.charmap], e.g. fr_FR.UTF-8"))
+		}
+
+		// Idempotency: already generated → success.
+		existing, err := oscmd.RunLines("localectl", "list-locales")
+		if err != nil {
+			return nil, huma.Error500InternalServerError("localectl failed", err)
+		}
+		if slices.Contains(existing, locale) {
+			return oscmd.OK(), nil
+		}
+
+		// Detect which generation path the host supports.
+		localeGenFile := "/etc/locale.gen"
+		_, hasFile := os.Stat(localeGenFile)
+		_, hasLocaleGen := exec.LookPath("locale-gen")
+		_, hasLocaledef := exec.LookPath("localedef")
+
+		switch {
+		case hasFile == nil && hasLocaleGen == nil:
+			if err := enableLocaleGen(localeGenFile, locale); err != nil {
+				return nil, err
+			}
+		case hasLocaledef == nil:
+			if err := generateLocaledef(locale); err != nil {
+				return nil, err
+			}
+		default:
+			return nil, huma.Error501NotImplemented(
+				"locale generation not supported on this host (no locale-gen or localedef found)")
+		}
+		return oscmd.OK(), nil
+	})
+}
+
+// enableLocaleGen uncomments the locale in /etc/locale.gen and runs locale-gen.
+// This is the Debian/Ubuntu/Arch path.
+func enableLocaleGen(path, locale string) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return huma.Error500InternalServerError("reading locale.gen failed", err)
+	}
+	newContent, found := uncommentLocaleGen(string(data), locale)
+	if !found {
+		return huma.Error400BadRequest("locale not available for generation: " + locale)
+	}
+	// Write atomically: a crash mid-write would leave /etc/locale.gen truncated
+	// and break every subsequent locale-gen on the host.
+	tmp := path + ".nadir.tmp"
+	if err := os.WriteFile(tmp, []byte(newContent), 0644); err != nil {
+		return huma.Error500InternalServerError("writing locale.gen failed", err)
+	}
+	if err := os.Rename(tmp, path); err != nil {
+		os.Remove(tmp)
+		return huma.Error500InternalServerError("replacing locale.gen failed", err)
+	}
+	if _, err := oscmd.Run("locale-gen"); err != nil {
+		return huma.Error500InternalServerError("locale-gen failed", err)
+	}
+	return nil
+}
+
+// uncommentLocaleGen finds a commented-out line for the given locale in a
+// locale.gen file and uncomments it. Returns the modified content and whether
+// a matching line was found. Pure function for testability.
+func uncommentLocaleGen(content, locale string) (string, bool) {
+	lines := strings.Split(content, "\n")
+	found := false
+	for i, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		// Match lines like "# fr_FR.UTF-8 UTF-8" or "#fr_FR.UTF-8 UTF-8".
+		if !strings.HasPrefix(trimmed, "#") {
+			// Also check if already uncommented (idempotent at the file level).
+			if strings.HasPrefix(trimmed, locale+" ") || trimmed == locale {
+				found = true
+			}
+			continue
+		}
+		uncommented := strings.TrimSpace(strings.TrimPrefix(trimmed, "#"))
+		if strings.HasPrefix(uncommented, locale+" ") || uncommented == locale {
+			lines[i] = uncommented
+			found = true
+		}
+	}
+	return strings.Join(lines, "\n"), found
+}
+
+// generateLocaledef generates a locale using localedef. This is the RHEL/Fedora
+// path where there is no /etc/locale.gen.
+func generateLocaledef(locale string) error {
+	// Parse "fr_FR.UTF-8" into language_territory="fr_FR" and charmap="UTF-8".
+	// If there is no dot, default to UTF-8 (the common case on modern systems).
+	langTerritory, charmap, _ := strings.Cut(locale, ".")
+	if charmap == "" {
+		charmap = "UTF-8"
+	}
+	if _, err := oscmd.Run("localedef", "-i", langTerritory, "-f", charmap, locale); err != nil {
+		return huma.Error500InternalServerError("localedef failed", err)
+	}
+	return nil
 }

internal/modules/system/power_test.go

@@ -3,16 +3,34 @@ package system
 import "testing"
 
 func TestWhenRe(t *testing.T) {
-	valid := []string{"now", "+0", "+5", "+120", "0:00", "9:30", "23:59", "07:05"}
-	for _, w := range valid {
-		if !whenRe.MatchString(w) {
-			t.Errorf("whenRe.MatchString(%q) = false, want true", w)
-		}
-	}
-	invalid := []string{"", "-r", "-h", "--help", "24:00", "9:60", "+5; reboot", "now ", "5", "1:2"}
-	for _, w := range invalid {
-		if whenRe.MatchString(w) {
-			t.Errorf("whenRe.MatchString(%q) = true, want false", w)
-		}
+	for _, tt := range []struct {
+		name  string
+		value string
+		want  bool
+	}{
+		{name: "now", value: "now", want: true},
+		{name: "plus zero", value: "+0", want: true},
+		{name: "plus five", value: "+5", want: true},
+		{name: "plus 120", value: "+120", want: true},
+		{name: "0:00", value: "0:00", want: true},
+		{name: "9:30", value: "9:30", want: true},
+		{name: "23:59", value: "23:59", want: true},
+		{name: "07:05", value: "07:05", want: true},
+		{name: "empty", value: "", want: false},
+		{name: "flag r", value: "-r", want: false},
+		{name: "flag h", value: "-h", want: false},
+		{name: "help", value: "--help", want: false},
+		{name: "24:00", value: "24:00", want: false},
+		{name: "9:60", value: "9:60", want: false},
+		{name: "injected command", value: "+5; reboot", want: false},
+		{name: "trailing space", value: "now ", want: false},
+		{name: "just digit", value: "5", want: false},
+		{name: "single colon", value: "1:2", want: false},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := whenRe.MatchString(tt.value); got != tt.want {
+				t.Errorf("whenRe.MatchString(%q) = %v, want %v", tt.value, got, tt.want)
+			}
+		})
 	}
 }

internal/modules/system/system_handler_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"reflect"
+	"strings"
 	"testing"
 
 	"nadir/internal/oscmd"
@@ -46,7 +47,7 @@ func TestSystemHandlers(t *testing.T) {
 		if reflect.DeepEqual(args, []string{"hostname"}) {
 			return oscmd.MockCommand{Stdout: "server01\n", ExitCode: 0}
 		}
-		if reflect.DeepEqual(args, []string{"set-hostname", "server02"}) {
+		if reflect.DeepEqual(args, []string{"set-hostname", "--", "server02"}) {
 			return oscmd.MockCommand{ExitCode: 0}
 		}
 		return oscmd.MockCommand{ExitCode: 1}
@@ -141,7 +142,7 @@ func TestSystemHandlers(t *testing.T) {
 	// 4. Test GET & POST /api/system/locale
 	oscmd.SetMock("localectl", func(args []string) oscmd.MockCommand {
 		if reflect.DeepEqual(args, []string{"status"}) {
-			statusOut := "   System Locale: LANG=it_IT.UTF-8\n       VC Keymap: it\n      X11 Layout: it\n"
+			statusOut := "   System Locale: LANG=it_IT.UTF-8\n                  LANGUAGE=en_US:\n       VC Keymap: it\n      X11 Layout: it\n"
 			return oscmd.MockCommand{Stdout: statusOut, ExitCode: 0}
 		}
 		if reflect.DeepEqual(args, []string{"list-locales"}) {
@@ -150,6 +151,9 @@ func TestSystemHandlers(t *testing.T) {
 		if reflect.DeepEqual(args, []string{"set-locale", "LANG=it_IT.UTF-8"}) {
 			return oscmd.MockCommand{ExitCode: 0}
 		}
+		if reflect.DeepEqual(args, []string{"set-locale", "LANG=it_IT.UTF-8", "LANGUAGE=en_US:"}) {
+			return oscmd.MockCommand{ExitCode: 0}
+		}
 		if reflect.DeepEqual(args, []string{"list-keymaps"}) {
 			return oscmd.MockCommand{Stdout: "it\nus\n", ExitCode: 0}
 		}
@@ -167,7 +171,7 @@ func TestSystemHandlers(t *testing.T) {
 	if err := json.Unmarshal(resp.Body.Bytes(), &localeRes.Body); err != nil {
 		t.Fatal(err)
 	}
-	if localeRes.Body.Lang != "it_IT.UTF-8" || localeRes.Body.VCKeymap != "it" {
+	if localeRes.Body.Lang != "it_IT.UTF-8" || localeRes.Body.Language != "en_US:" || localeRes.Body.VCKeymap != "it" {
 		t.Errorf("got locale status: %+v", localeRes.Body)
 	}
 
@@ -185,6 +189,17 @@ func TestSystemHandlers(t *testing.T) {
 		t.Errorf("set locale: got %d, want %d", resp.Code, http.StatusOK)
 	}
 
+	resp = api.Post("/api/system/locale", struct {
+		Lang     string `json:"lang"`
+		Language string `json:"language"`
+	}{
+		Lang:     "it_IT.UTF-8",
+		Language: "en_US:",
+	})
+	if resp.Code != http.StatusOK {
+		t.Errorf("set locale with language: got %d, want %d", resp.Code, http.StatusOK)
+	}
+
 	resp = api.Get("/api/system/keymaps")
 	if resp.Code != http.StatusOK {
 		t.Errorf("list keymaps: got %d, want %d", resp.Code, http.StatusOK)
@@ -199,6 +214,37 @@ func TestSystemHandlers(t *testing.T) {
 		t.Errorf("set keymap: got %d, want %d", resp.Code, http.StatusOK)
 	}
 
+	// 4b. Test POST /api/system/locale/generate (validation & idempotent)
+	// Empty locale → 422 (huma validates non-empty before handler runs)
+	resp = api.Post("/api/system/locale/generate", struct {
+		Locale string `json:"locale"`
+	}{
+		Locale: "",
+	})
+	if resp.Code != http.StatusBadRequest && resp.Code != http.StatusUnprocessableEntity {
+		t.Errorf("generate empty locale: got %d, want 400 or 422", resp.Code)
+	}
+
+	// Invalid format → 400
+	resp = api.Post("/api/system/locale/generate", struct {
+		Locale string `json:"locale"`
+	}{
+		Locale: "not-a-locale!!",
+	})
+	if resp.Code != http.StatusBadRequest {
+		t.Errorf("generate invalid locale: got %d, want %d", resp.Code, http.StatusBadRequest)
+	}
+
+	// Already generated (it_IT.UTF-8 is in list-locales mock) → 200 (idempotent)
+	resp = api.Post("/api/system/locale/generate", struct {
+		Locale string `json:"locale"`
+	}{
+		Locale: "it_IT.UTF-8",
+	})
+	if resp.Code != http.StatusOK {
+		t.Errorf("generate existing locale (idempotent): got %d, want %d", resp.Code, http.StatusOK)
+	}
+
 	// 5. Test POST /api/system/reboot and /api/system/poweroff
 	oscmd.SetMock("shutdown", func(args []string) oscmd.MockCommand {
 		if reflect.DeepEqual(args, []string{"-r", "now"}) || reflect.DeepEqual(args, []string{"-h", "now"}) {
@@ -225,3 +271,58 @@ func TestSystemHandlers(t *testing.T) {
 		t.Errorf("poweroff: got %d, want %d", resp.Code, http.StatusOK)
 	}
 }
+
+func TestUncommentLocaleGen(t *testing.T) {
+	const sampleLocaleGen = `# This file lists locales that you wish to have built.
+#
+# en_US.UTF-8 UTF-8
+# fr_FR.UTF-8 UTF-8
+# de_DE.UTF-8 UTF-8
+it_IT.UTF-8 UTF-8
+`
+
+	tests := []struct {
+		name       string
+		locale     string
+		wantFound  bool
+		wantSubstr string // substring that should appear uncommented
+	}{
+		{
+			name:       "uncomment commented locale",
+			locale:     "fr_FR.UTF-8",
+			wantFound:  true,
+			wantSubstr: "\nfr_FR.UTF-8 UTF-8\n",
+		},
+		{
+			name:      "already uncommented",
+			locale:    "it_IT.UTF-8",
+			wantFound: true,
+		},
+		{
+			name:      "locale not in file",
+			locale:    "ja_JP.UTF-8",
+			wantFound: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, found := uncommentLocaleGen(sampleLocaleGen, tt.locale)
+			if found != tt.wantFound {
+				t.Errorf("found = %v, want %v", found, tt.wantFound)
+			}
+			if tt.wantSubstr != "" && !contains(result, tt.wantSubstr) {
+				t.Errorf("result does not contain %q:\n%s", tt.wantSubstr, result)
+			}
+			// The commented versions of OTHER locales should remain commented.
+			if tt.locale == "fr_FR.UTF-8" && !contains(result, "# en_US.UTF-8 UTF-8") {
+				t.Errorf("other locales should stay commented:\n%s", result)
+			}
+		})
+	}
+}
+
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) && (s == substr || len(substr) == 0 ||
+		(len(s) > 0 && strings.Contains(s, substr)))
+}

internal/modules/terminal/terminal.go

@@ -1,209 +0,0 @@
-package terminal
-
-import (
-	"context"
-	"encoding/json"
-	"net/http"
-	"os/exec"
-	"strings"
-	"sync/atomic"
-	"time"
-
-	"nadir/internal/auth"
-	"nadir/internal/module"
-	"nadir/internal/rbac"
-
-	"github.com/coder/websocket"
-	"github.com/creack/pty"
-	"github.com/danielgtaylor/huma/v2"
-	"github.com/danielgtaylor/huma/v2/adapters/humago"
-)
-
-// tagTerminal is the OpenAPI tag for this module (registered in server.go),
-// keeping tags 1:1 with modules per the project convention.
-const tagTerminal = "Terminal"
-
-const (
-	// maxTerminals caps concurrent shells so a buggy frontend or careless admin
-	// can't pile up PTYs (guideline: limit everything). Raise if it's ever a real
-	// limit in practice.
-	maxTerminals = 10
-	// idleTimeout closes a session after this long with no I/O in either
-	// direction, reclaiming abandoned shells.
-	idleTimeout = 15 * time.Minute
-)
-
-// terminalSem is the concurrency limiter; a slot is held for the life of a session.
-var terminalSem = make(chan struct{}, maxTerminals)
-
-type terminalModule struct {
-	sessions *auth.SessionStore
-}
-
-// New creates a new Terminal module that allows interactive shell access.
-func New(sessions *auth.SessionStore) module.Module {
-	return &terminalModule{sessions: sessions}
-}
-
-func (m *terminalModule) ID() string   { return "terminal" }
-
-func (m *terminalModule) Permissions() []rbac.Permission {
-	return []rbac.Permission{rbac.Root}
-}
-
-type TerminalInput struct {
-	Ctx huma.Context `json:"-"`
-}
-
-// Resolve extracts the huma.Context into the input struct.
-func (i *TerminalInput) Resolve(ctx huma.Context) []error {
-	i.Ctx = ctx
-	return nil
-}
-
-type resizeMessage struct {
-	Cols uint16 `json:"cols"`
-	Rows uint16 `json:"rows"`
-}
-
-func (m *terminalModule) Register(api huma.API) {
-	huma.Register(api, huma.Operation{
-		OperationID: "terminal-connect",
-		Method:      "GET",
-		Path:        "/api/terminal",
-		Summary:     "Connect to an interactive terminal",
-		Description: "Upgrades the connection to a WebSocket and spawns a PTY shell as the logged-in user. Send JSON `{cols, rows}` text messages to resize, and raw binary/text messages for stdin. This is a raw WebSocket endpoint — it cannot be exercised from the API docs \"Try it\" panel; use a WebSocket client.",
-		Tags:        []string{tagTerminal},
-		Metadata:    map[string]any{"module": m.ID(), "permission": string(rbac.Root)},
-		Errors:      []int{401, 403, 426, 500},
-	}, func(ctx context.Context, in *TerminalInput) (*struct{}, error) {
-		// The RBAC middleware already authenticated this request and enforced the
-		// "root" permission before we got here. We re-read the session only to get
-		// the username for `su`; the 401 below is the fallback for when the module
-		// is mounted without the middleware (e.g. in unit tests).
-		cookie, err := huma.ReadCookie(in.Ctx, "nadir_session_id")
-		if err != nil || cookie == nil {
-			return nil, huma.Error401Unauthorized("unauthorized")
-		}
-
-		sess, ok := m.sessions.GetByToken(cookie.Value)
-		if !ok {
-			return nil, huma.Error401Unauthorized("unauthorized")
-		}
-
-		req, res := humago.Unwrap(in.Ctx)
-		if req == nil || res == nil {
-			return nil, huma.Error500InternalServerError("missing http context")
-		}
-
-		// Reject plain GETs (e.g. the docs "Try it" button) with a clear 426 rather
-		// than letting websocket.Accept emit a raw protocol-violation error.
-		if !strings.EqualFold(req.Header.Get("Upgrade"), "websocket") {
-			return nil, huma.NewError(http.StatusUpgradeRequired,
-				"this endpoint requires a WebSocket connection; connect with a WebSocket client")
-		}
-
-		// InsecureSkipVerify is deliberately NOT set: coder/websocket then enforces
-		// that the Origin host matches the request Host, rejecting cross-site upgrade
-		// attempts. Defense-in-depth on top of the SameSite=Strict session cookie —
-		// important because this endpoint hands out an interactive shell.
-		conn, err := websocket.Accept(res, req, nil)
-		if err != nil {
-			// websocket.Accept already wrote the error response (e.g. 403 on an
-			// Origin mismatch). Just stop; writing again would corrupt the response.
-			return nil, nil
-		}
-		defer conn.CloseNow()
-
-		// Bound concurrent shells: take a slot or reject (don't pile up PTYs).
-		select {
-		case terminalSem <- struct{}{}:
-			defer func() { <-terminalSem }()
-		default:
-			conn.Close(websocket.StatusTryAgainLater, "too many terminal sessions")
-			return nil, nil
-		}
-
-		// Launch the user's login shell via su.
-		// "su - <username>" ensures we get their actual environment and shell.
-		cmd := exec.CommandContext(req.Context(), "su", "-", sess.Username)
-
-		// Start the command with a PTY.
-		ptmx, err := pty.Start(cmd)
-		if err != nil {
-			conn.Close(websocket.StatusInternalError, "failed to start pty")
-			return nil, nil
-		}
-		defer ptmx.Close()
-
-		// lastActive is bumped by both pumps; the watchdog uses it to close idle
-		// sessions. Output activity (e.g. `top`) counts, so it isn't killed.
-		var lastActive atomic.Int64
-		lastActive.Store(time.Now().UnixNano())
-		go func() {
-			tick := time.NewTicker(idleTimeout / 4)
-			defer tick.Stop()
-			for {
-				select {
-				case <-req.Context().Done():
-					return
-				case <-tick.C:
-					if time.Since(time.Unix(0, lastActive.Load())) > idleTimeout {
-						conn.Close(websocket.StatusGoingAway, "idle timeout")
-						return
-					}
-				}
-			}
-		}()
-
-		// Pump stdout/stderr from PTY to WebSocket.
-		go func() {
-			buf := make([]byte, 8192)
-			for {
-				n, err := ptmx.Read(buf)
-				if err != nil {
-					break
-				}
-				lastActive.Store(time.Now().UnixNano())
-				// We write PTY output as binary messages. The frontend (e.g., xterm.js)
-				// can handle UTF-8 binary or text transparently.
-				err = conn.Write(req.Context(), websocket.MessageBinary, buf[:n])
-				if err != nil {
-					break
-				}
-			}
-			conn.Close(websocket.StatusNormalClosure, "")
-		}()
-
-		// Pump stdin and resize commands from WebSocket to PTY.
-		for {
-			typ, b, err := conn.Read(req.Context())
-			if err != nil {
-				break
-			}
-			lastActive.Store(time.Now().UnixNano())
-
-			if typ == websocket.MessageText {
-				var resize resizeMessage
-				if err := json.Unmarshal(b, &resize); err == nil && resize.Cols > 0 && resize.Rows > 0 {
-					// Handle resize
-					_ = pty.Setsize(ptmx, &pty.Winsize{
-						Cols: resize.Cols,
-						Rows: resize.Rows,
-					})
-					continue
-				}
-			}
-
-			// If not a valid resize message, or if it's MessageBinary, pass to PTY stdin.
-			_, _ = ptmx.Write(b)
-		}
-
-		// The read loop has ended (client gone or PTY closed). Tear down the shell
-		// and reap it: closing the PTY sends EOF, Kill covers shells that ignore it.
-		_ = ptmx.Close()
-		_ = cmd.Process.Kill()
-		_ = cmd.Wait()
-		return nil, nil
-	})
-}

internal/modules/terminal/terminal_test.go

@@ -1,124 +0,0 @@
-package terminal
-
-import (
-	"context"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-	"time"
-
-	"nadir/internal/auth"
-
-	"github.com/coder/websocket"
-	"github.com/danielgtaylor/huma/v2"
-	"github.com/danielgtaylor/huma/v2/adapters/humago"
-)
-
-func TestTerminalConnectUnauthorized(t *testing.T) {
-	sessions, err := auth.NewSessionStore("file::memory:?cache=shared")
-	if err != nil {
-		t.Fatalf("session db: %v", err)
-	}
-
-	mux := http.NewServeMux()
-	api := humago.New(mux, huma.DefaultConfig("Test", "1.0.0"))
-	mod := New(sessions)
-	mod.Register(api)
-
-	srv := httptest.NewServer(mux)
-	defer srv.Close()
-
-	wsURL := strings.Replace(srv.URL, "http://", "ws://", 1) + "/api/terminal"
-
-	// Try without cookie
-	ctx, cancel := context.WithTimeout(t.Context(), 2*time.Second)
-	defer cancel()
-
-	_, resp, err := websocket.Dial(ctx, wsURL, nil)
-	if err == nil {
-		t.Fatal("expected error, got success")
-	}
-	if resp != nil && resp.StatusCode != http.StatusUnauthorized {
-		t.Errorf("expected 401, got %d", resp.StatusCode)
-	}
-}
-
-func TestTerminalConnectPlainGET(t *testing.T) {
-	// An authenticated but non-WebSocket GET (e.g. the docs "Try it" button) must
-	// get a clean 426 Upgrade Required, not a raw websocket protocol error.
-	sessions, err := auth.NewSessionStore("file::memory:?cache=shared")
-	if err != nil {
-		t.Fatalf("session db: %v", err)
-	}
-	token, err := sessions.Create("root")
-	if err != nil {
-		t.Fatalf("create session: %v", err)
-	}
-
-	mux := http.NewServeMux()
-	api := humago.New(mux, huma.DefaultConfig("Test", "1.0.0"))
-	New(sessions).Register(api)
-
-	srv := httptest.NewServer(mux)
-	defer srv.Close()
-
-	req, _ := http.NewRequest(http.MethodGet, srv.URL+"/api/terminal", nil)
-	req.Header.Set("Cookie", "nadir_session_id="+token)
-	resp, err := http.DefaultClient.Do(req)
-	if err != nil {
-		t.Fatalf("GET failed: %v", err)
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode != http.StatusUpgradeRequired {
-		t.Errorf("expected 426, got %d", resp.StatusCode)
-	}
-}
-
-func TestTerminalConnectAuthorized(t *testing.T) {
-	// Root or specific system configs might cause PTY or su to fail if run in constrained environments.
-	// But we expect the websocket upgrade to succeed and then maybe close with an error if PTY fails.
-	sessions, err := auth.NewSessionStore("file::memory:?cache=shared")
-	if err != nil {
-		t.Fatalf("session db: %v", err)
-	}
-
-	token, err := sessions.Create("root")
-	if err != nil {
-		t.Fatalf("create session: %v", err)
-	}
-
-	mux := http.NewServeMux()
-	api := humago.New(mux, huma.DefaultConfig("Test", "1.0.0"))
-	mod := New(sessions)
-	mod.Register(api)
-
-	srv := httptest.NewServer(mux)
-	defer srv.Close()
-
-	wsURL := strings.Replace(srv.URL, "http://", "ws://", 1) + "/api/terminal"
-
-	ctx, cancel := context.WithTimeout(t.Context(), 2*time.Second)
-	defer cancel()
-
-	opts := &websocket.DialOptions{
-		HTTPHeader: http.Header{},
-	}
-	opts.HTTPHeader.Set("Cookie", "nadir_session_id="+token)
-
-	conn, resp, err := websocket.Dial(ctx, wsURL, opts)
-	if err != nil {
-		// Depending on the test environment, "su" or "pty" might fail, but
-		// the websocket upgrade itself should succeed before it drops.
-		// If it fails to upgrade, that's a real error.
-		t.Fatalf("dial failed: %v (status %d)", err, resp.StatusCode)
-	}
-	defer conn.CloseNow()
-
-	// The connection was upgraded successfully.
-	// If PTY allocation failed or su failed, the server might close the connection immediately.
-	// We just verify the upgrade succeeded.
-	if resp.StatusCode != http.StatusSwitchingProtocols {
-		t.Errorf("expected 101, got %d", resp.StatusCode)
-	}
-}

internal/modules/users/module.go

@@ -8,9 +8,17 @@ import (
 
 const ModuleID = "users"
 
-type Module struct{}
+// sessionStore is the subset of SessionStore that password changes need:
+// invalidate all existing sessions for a user whose password just changed.
+type sessionStore interface {
+	DeleteByUsername(username string) error
+}
 
-func New() *Module { return &Module{} }
+type Module struct {
+	sessions sessionStore
+}
+
+func New(sessions sessionStore) *Module { return &Module{sessions: sessions} }
 
 func (m *Module) ID() string   { return ModuleID }
 
@@ -21,7 +29,7 @@ func (m *Module) Permissions() []rbac.Permission {
 }
 
 func (m *Module) Register(api huma.API) {
-	registerUsers(api)
+	registerUsers(api, m.sessions)
 }
 
 func op(permission string) map[string]any {

internal/modules/users/users.go

@@ -2,6 +2,7 @@ package users
 
 import (
 	"context"
+	"log"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -91,7 +92,7 @@ type UserGroupsOutput struct {
 	}
 }
 
-func registerUsers(api huma.API) {
+func registerUsers(api huma.API, sessions sessionStore) {
 	huma.Register(api, huma.Operation{
 		OperationID: "users-list",
 		Method:      "GET",
@@ -105,7 +106,7 @@ func registerUsers(api huma.API) {
 	}, func(ctx context.Context, _ *struct{}) (*ListUsersOutput, error) {
 		list, err := listUsers()
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		}
 		out := &ListUsersOutput{}
 		out.Body.Users = list
@@ -127,7 +128,7 @@ func registerUsers(api huma.API) {
 		}
 		u, ok, err := lookupUser(in.Username)
 		if err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		}
 		if !ok {
 			return nil, huma.Error404NotFound("user not found: " + in.Username)
@@ -163,7 +164,7 @@ func registerUsers(api huma.API) {
 			return nil, huma.Error400BadRequest("home must be an absolute path")
 		}
 		if _, ok, err := lookupUser(in.Body.Username); err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		} else if ok {
 			return nil, huma.Error409Conflict("user already exists: " + in.Body.Username)
 		}
@@ -212,7 +213,7 @@ func registerUsers(api huma.API) {
 			return nil, err
 		}
 		if _, ok, err := lookupUser(in.Username); err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		} else if !ok {
 			return nil, huma.Error404NotFound("user not found: " + in.Username)
 		}
@@ -253,7 +254,7 @@ func registerUsers(api huma.API) {
 			return nil, huma.Error400BadRequest("password may not contain newlines")
 		}
 		if _, ok, err := lookupUser(in.Username); err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		} else if !ok {
 			return nil, huma.Error404NotFound("user not found: " + in.Username)
 		}
@@ -261,6 +262,11 @@ func registerUsers(api huma.API) {
 		if _, err := oscmd.RunStdin(in.Username+":"+in.Body.Password+"\n", "chpasswd"); err != nil {
 			return nil, huma.Error500InternalServerError("chpasswd failed", err)
 		}
+		if sessions != nil {
+			if err := sessions.DeleteByUsername(in.Username); err != nil {
+				log.Printf("failed to invalidate sessions for %s: %v", in.Username, err)
+			}
+		}
 		return oscmd.OK(), nil
 	})
 
@@ -290,7 +296,7 @@ func registerUsers(api huma.API) {
 			}
 		}
 		if _, ok, err := lookupUser(in.Username); err != nil {
-			return nil, huma.Error500InternalServerError("read "+passwdPath+" failed", err)
+			return nil, huma.Error500InternalServerError("user lookup failed", err)
 		} else if !ok {
 			return nil, huma.Error404NotFound("user not found: " + in.Username)
 		}

internal/modules/users/users_handler_test.go

@@ -28,7 +28,7 @@ func TestUsersHandlers(t *testing.T) {
 
 	mux := http.NewServeMux()
 	api := humatest.Wrap(t, humago.New(mux, huma.DefaultConfig("Test", "1.0.0")))
-	registerUsers(api)
+	registerUsers(api, nil)
 
 	// 1. Test GET /api/users
 	resp := api.Get("/api/users")

internal/modules/users/users_test.go

@@ -28,26 +28,34 @@ short:x:2:2
 }
 
 func TestValidateUsername(t *testing.T) {
-	valid := []string{"alice", "_svc", "user-1", "a", "machine$", "abc_def"}
-	for _, n := range valid {
-		if err := validateUsername(n); err != nil {
-			t.Errorf("validateUsername(%q) = %v, want nil", n, err)
-		}
-	}
-
-	invalid := []string{
-		"",       // empty
-		"-rf",    // leading dash (flag injection)
-		"Alice",  // uppercase
-		"1user",  // leading digit
-		"a b",    // space
-		"foo;rm", // shell metachar
-		"root:x", // colon (passwd separator)
-		"waytoolongusernamethatexceedsthirtytwochars", // >32
-	}
-	for _, n := range invalid {
-		if err := validateUsername(n); err == nil {
-			t.Errorf("validateUsername(%q) = nil, want error", n)
-		}
+	for _, n := range []struct {
+		name  string
+		value string
+		valid bool
+	}{
+		{name: "alice", value: "alice", valid: true},
+		{name: "underscore prefix", value: "_svc", valid: true},
+		{name: "hyphen", value: "user-1", valid: true},
+		{name: "single char", value: "a", valid: true},
+		{name: "dollar suffix", value: "machine$", valid: true},
+		{name: "underscore", value: "abc_def", valid: true},
+		{name: "empty", value: "", valid: false},
+		{name: "leading dash", value: "-rf", valid: false},
+		{name: "uppercase", value: "Alice", valid: false},
+		{name: "leading digit", value: "1user", valid: false},
+		{name: "space", value: "a b", valid: false},
+		{name: "shell metachar", value: "foo;rm", valid: false},
+		{name: "colon", value: "root:x", valid: false},
+		{name: "too long", value: "waytoolongusernamethatexceedsthirtytwochars", valid: false},
+	} {
+		t.Run(n.name, func(t *testing.T) {
+			err := validateUsername(n.value)
+			if n.valid && err != nil {
+				t.Errorf("validateUsername(%q) = %v, want nil", n.value, err)
+			}
+			if !n.valid && err == nil {
+				t.Errorf("validateUsername(%q) = nil, want error", n.value)
+			}
+		})
 	}
 }

internal/mounts/mounts_test.go

@@ -25,16 +25,22 @@ func TestParseProc(t *testing.T) {
 }
 
 func TestUnescape(t *testing.T) {
-	cases := map[string]string{
-		`/mnt/my\040disk`: "/mnt/my disk",
-		`/no/escapes`:     "/no/escapes",
-		`tab\011here`:     "tab\there",
-		`back\134slash`:   `back\slash`,
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{name: "octal space", in: `/mnt/my\040disk`, want: "/mnt/my disk"},
+		{name: "no escapes", in: `/no/escapes`, want: "/no/escapes"},
+		{name: "tab", in: `tab\011here`, want: "tab\there"},
+		{name: "backslash", in: `back\134slash`, want: `back\slash`},
 	}
-	for in, want := range cases {
-		if got := Unescape(in); got != want {
-			t.Errorf("Unescape(%q) = %q, want %q", in, got, want)
-		}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Unescape(tt.in); got != tt.want {
+				t.Errorf("Unescape(%q) = %q, want %q", tt.in, got, tt.want)
+			}
+		})
 	}
 }
 

internal/openapitest/openapi_test.go

@@ -21,7 +21,6 @@ import (
 	"nadir/internal/modules/services"
 	"nadir/internal/modules/storage"
 	"nadir/internal/modules/system"
-	"nadir/internal/modules/terminal"
 	"nadir/internal/modules/users"
 	"nadir/internal/rbac"
 
@@ -44,13 +43,12 @@ func TestOpenAPISchemaNoCollisions(t *testing.T) {
 	mods := []module.Module{
 		system.New(),
 		services.New(nil),
-		users.New(),
+		users.New(nil),
 		groups.New(),
 		packages.New(),
 		networking.New(),
 		storage.New(),
 		audit.New(auditStore),
-		terminal.New(sessions),
 	}
 
 	mux := http.NewServeMux()
@@ -60,7 +58,7 @@ func TestOpenAPISchemaNoCollisions(t *testing.T) {
 	}
 	meta.Register(api, mods)
 	meta.RegisterHealth(api, sessions)
-	meta.RegisterWhoami(api, sessions, roles, mods)
+	meta.RegisterWhoami(api, sessions, nil, roles, mods)
 	auth.RegisterLogin(api, sessions, auditStore, true)
 	auth.RegisterLogout(api, sessions, true)
 

internal/rbac/middleware_test.go

@@ -41,8 +41,6 @@ func TestRbacMiddleware(t *testing.T) {
 		},
 	})
 	r.AssignRole("alice", "test-role")
-	// A machine credential is just another RBAC subject: the token name is
-	// assigned a role exactly like a username.
 	r.AssignRole("dash", "test-role")
 
 	mux := http.NewServeMux()
@@ -76,81 +74,91 @@ func TestRbacMiddleware(t *testing.T) {
 		return &struct{ Body string }{Body: "gated-write"}, nil
 	})
 
-	// 1. Test public route
-	resp := api.Get("/public")
-	if resp.Code != http.StatusOK {
-		t.Errorf("public GET: got status %d, want %d", resp.Code, http.StatusOK)
-	}
+	t.Run("public route", func(t *testing.T) {
+		resp := api.Get("/public")
+		if resp.Code != http.StatusOK {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusOK)
+		}
+	})
 
-	// 2. Test gated route without cookie -> 401 Unauthorized
-	resp = api.Get("/gated-read")
-	if resp.Code != http.StatusUnauthorized {
-		t.Errorf("gated GET no cookie: got status %d, want %d", resp.Code, http.StatusUnauthorized)
-	}
+	t.Run("no auth returns 401", func(t *testing.T) {
+		resp := api.Get("/gated-read")
+		if resp.Code != http.StatusUnauthorized {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusUnauthorized)
+		}
+	})
 
-	// 3. Test gated route with invalid cookie -> 401 Unauthorized
-	resp = api.Get("/gated-read", "Cookie: nadir_session_id=invalid")
-	if resp.Code != http.StatusUnauthorized {
-		t.Errorf("gated GET invalid cookie: got status %d, want %d", resp.Code, http.StatusUnauthorized)
-	}
+	t.Run("invalid cookie returns 401", func(t *testing.T) {
+		resp := api.Get("/gated-read", "Cookie: nadir_session_id=invalid")
+		if resp.Code != http.StatusUnauthorized {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusUnauthorized)
+		}
+	})
 
-	// Create valid session
-	token, err := sessions.Create("alice")
-	if err != nil {
-		t.Fatal(err)
-	}
+	var aliceToken string
+	t.Run("valid session returns 200", func(t *testing.T) {
+		var err error
+		aliceToken, err = sessions.Create("alice")
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp := api.Get("/gated-read", "Cookie: nadir_session_id="+aliceToken)
+		if resp.Code != http.StatusOK {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusOK)
+		}
+	})
 
-	// 4. Test gated route with valid cookie -> 200 OK
-	resp = api.Get("/gated-read", "Cookie: nadir_session_id="+token)
-	if resp.Code != http.StatusOK {
-		t.Errorf("gated GET valid cookie: got status %d, want %d", resp.Code, http.StatusOK)
-	}
+	t.Run("csrf mismatched origin returns 403", func(t *testing.T) {
+		resp := api.Post("/gated-write", "Cookie: nadir_session_id="+aliceToken, "Origin: http://evil.com", "Host: example.com", struct{}{})
+		if resp.Code != http.StatusForbidden {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusForbidden)
+		}
+	})
 
-	// 5. Test CSRF violation: POST with mismatched Origin header -> 403 Forbidden
-	resp = api.Post("/gated-write", "Cookie: nadir_session_id="+token, "Origin: http://evil.com", "Host: example.com", struct{}{})
-	if resp.Code != http.StatusForbidden {
-		t.Errorf("CSRF mismatched Origin: got status %d, want %d", resp.Code, http.StatusForbidden)
-	}
+	t.Run("csrf matching origin returns 200", func(t *testing.T) {
+		resp := api.Post("/gated-write", "Cookie: nadir_session_id="+aliceToken, "Origin: http://example.com", "Host: example.com", struct{}{})
+		if resp.Code != http.StatusOK {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusOK)
+		}
+	})
 
-	// 6. Test CSRF success: POST with matching Origin header -> 200 OK
-	resp = api.Post("/gated-write", "Cookie: nadir_session_id="+token, "Origin: http://example.com", "Host: example.com", struct{}{})
-	if resp.Code != http.StatusOK {
-		t.Errorf("CSRF matching Origin: got status %d, want %d", resp.Code, http.StatusOK)
-	}
+	t.Run("unauthorized user returns 403", func(t *testing.T) {
+		bobToken, err := sessions.Create("bob")
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp := api.Get("/gated-read", "Cookie: nadir_session_id="+bobToken)
+		if resp.Code != http.StatusForbidden {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusForbidden)
+		}
+	})
 
-	// 7. Test gated route with unauthorized user -> 403 Forbidden
-	tokenBob, err := sessions.Create("bob")
-	if err != nil {
-		t.Fatal(err)
-	}
-	resp = api.Get("/gated-read", "Cookie: nadir_session_id="+tokenBob)
-	if resp.Code != http.StatusForbidden {
-		t.Errorf("bob unauthorized GET: got status %d, want %d", resp.Code, http.StatusForbidden)
-	}
+	t.Run("valid bearer token returns 200", func(t *testing.T) {
+		rawToken, err := tokenStore.Create("dash")
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp := api.Get("/gated-read", "Authorization: Bearer "+rawToken)
+		if resp.Code != http.StatusOK {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusOK)
+		}
+	})
 
-	// 8. Bearer token for an assigned name -> 200 OK
-	rawToken, err := tokenStore.Create("dash")
-	if err != nil {
-		t.Fatal(err)
-	}
-	resp = api.Get("/gated-read", "Authorization: Bearer "+rawToken)
-	if resp.Code != http.StatusOK {
-		t.Errorf("valid bearer GET: got status %d, want %d", resp.Code, http.StatusOK)
-	}
+	t.Run("bogus bearer token returns 401", func(t *testing.T) {
+		resp := api.Get("/gated-read", "Authorization: Bearer nad_deadbeef")
+		if resp.Code != http.StatusUnauthorized {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusUnauthorized)
+		}
+	})
 
-	// 9. Bogus bearer token -> 401 Unauthorized
-	resp = api.Get("/gated-read", "Authorization: Bearer nad_deadbeef")
-	if resp.Code != http.StatusUnauthorized {
-		t.Errorf("bogus bearer GET: got status %d, want %d", resp.Code, http.StatusUnauthorized)
-	}
-
-	// 10. Bearer token with no role assignment -> 403 Forbidden
-	rawUnassigned, err := tokenStore.Create("orphan")
-	if err != nil {
-		t.Fatal(err)
-	}
-	resp = api.Get("/gated-read", "Authorization: Bearer "+rawUnassigned)
-	if resp.Code != http.StatusForbidden {
-		t.Errorf("unassigned bearer GET: got status %d, want %d", resp.Code, http.StatusForbidden)
-	}
+	t.Run("unassigned bearer token returns 403", func(t *testing.T) {
+		rawUnassigned, err := tokenStore.Create("orphan")
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp := api.Get("/gated-read", "Authorization: Bearer "+rawUnassigned)
+		if resp.Code != http.StatusForbidden {
+			t.Errorf("got status %d, want %d", resp.Code, http.StatusForbidden)
+		}
+	})
 }

minisign.pub

@@ -0,0 +1,2 @@
+untrusted comment: minisign public key: 702ABD7F45200669
+RWRpBiBFf70qcEXS0cOS+8tZ1hpoLj9mX0V5OiE8qYIIZsetU8hNA4Ou

tools/sign-checksums/main.go

@@ -0,0 +1,54 @@
+// Command sign-checksums is a CI helper that signs a file using minisign.
+//
+// The minisign CLI reads passwords from /dev/tty, which doesn't exist in CI
+// runners. This program uses the library directly: password and encrypted
+// secret key come from environment variables, no terminal required.
+//
+// Usage (in CI):
+//
+//	MINISIGN_SECRET_KEY=... MINISIGN_PASSWORD=... go run ./tools/sign-checksums dist/sha256sums.txt
+//
+// Produces dist/sha256sums.txt.minisig alongside the input.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"aead.dev/minisign"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "usage: sign-checksums <file>\n")
+		os.Exit(2)
+	}
+	filePath := os.Args[1]
+
+	password := os.Getenv("MINISIGN_PASSWORD")
+	keyBytes := []byte(os.Getenv("MINISIGN_SECRET_KEY"))
+	if len(keyBytes) == 0 {
+		fmt.Fprintln(os.Stderr, "MINISIGN_SECRET_KEY is not set")
+		os.Exit(1)
+	}
+
+	key, err := minisign.DecryptKey(password, keyBytes)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "decrypt key: %v\n", err)
+		os.Exit(1)
+	}
+
+	message, err := os.ReadFile(filePath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "read %s: %v\n", filePath, err)
+		os.Exit(1)
+	}
+
+	sig := minisign.Sign(key, message)
+	sigPath := filePath + ".minisig"
+	if err := os.WriteFile(sigPath, sig, 0644); err != nil {
+		fmt.Fprintf(os.Stderr, "write %s: %v\n", sigPath, err)
+		os.Exit(1)
+	}
+	fmt.Printf("signed %s -> %s\n", filePath, sigPath)
+}