fix(cli): confine agent runtime paths

cmd/elydora/plugins/droid.go

@@ -153,14 +153,15 @@ func (p *DroidPlugin) Status() (PluginStatus, error) {
 }
 
 func droidAgentDirectory(agentID string) (string, string, error) {
-	if agentID == "" || agentID == "." || agentID == ".." || filepath.IsAbs(agentID) || filepath.Base(agentID) != agentID {
-		return "", "", fmt.Errorf("agent_id must be a single non-empty path segment")
-	}
 	runtimeRoot, err := droidRuntimeRoot()
 	if err != nil {
 		return "", "", err
 	}
-	return runtimeRoot, filepath.Join(runtimeRoot, agentID), nil
+	agentDirectory, err := ResolveAgentRuntimeDirectory(agentID)
+	if err != nil {
+		return "", "", err
+	}
+	return runtimeRoot, agentDirectory, nil
 }
 
 func droidSettingsDocument(settings *droidDocument) *droidDocument {

cmd/elydora/plugins/hooktemplate.go

@@ -12,7 +12,7 @@ import (
 // It always exits 0 so it never blocks the host agent.
 func GenerateHookScript(destPath string, config InstallConfig) error {
 	dir := filepath.Dir(destPath)
-	if err := os.MkdirAll(dir, 0755); err != nil {
+	if err := EnsurePrivateDirectory(dir); err != nil {
 		return fmt.Errorf("create hook script directory: %w", err)
 	}
 
@@ -32,13 +32,9 @@ func GenerateHookScript(destPath string, config InstallConfig) error {
 // ~/.elydora/<agentId>/config.json and ~/.elydora/<agentId>/private.key so that
 // the generated hook script can read them at runtime without embedding secrets.
 func writeAgentConfig(config InstallConfig) error {
-	home, err := os.UserHomeDir()
+	agentDir, err := PrepareAgentRuntimeDirectory(config.AgentID)
 	if err != nil {
-		return fmt.Errorf("resolve home directory: %w", err)
-	}
-	agentDir := filepath.Join(home, ".elydora", config.AgentID)
-	if err := os.MkdirAll(agentDir, 0755); err != nil {
-		return fmt.Errorf("create agent directory: %w", err)
+		return err
 	}
 
 	baseURL := config.BaseURL

cmd/elydora/plugins/jsonutil.go

@@ -55,18 +55,18 @@ func writeJSONFile(path string, data map[string]interface{}) error {
 
 // hookScriptPath returns the default path for the hook script inside ~/.elydora/<agentId>/.
 func hookScriptPath(agentId string) (string, error) {
-	home, err := os.UserHomeDir()
+	agentDirectory, err := ResolveAgentRuntimeDirectory(agentId)
 	if err != nil {
-		return "", fmt.Errorf("resolve home directory: %w", err)
+		return "", err
 	}
-	return filepath.Join(home, ".elydora", agentId, "hook.js"), nil
+	return filepath.Join(agentDirectory, "hook.js"), nil
 }
 
 // guardScriptPath returns the default path for the guard script inside ~/.elydora/<agentId>/.
 func guardScriptPath(agentId string) (string, error) {
-	home, err := os.UserHomeDir()
+	agentDirectory, err := ResolveAgentRuntimeDirectory(agentId)
 	if err != nil {
-		return "", fmt.Errorf("resolve home directory: %w", err)
+		return "", err
 	}
-	return filepath.Join(home, ".elydora", agentId, "guard.js"), nil
+	return filepath.Join(agentDirectory, "guard.js"), nil
 }

cmd/elydora/plugins/qwen.go

@@ -119,14 +119,15 @@ func (p *QwenPlugin) Status() (PluginStatus, error) {
 }
 
 func qwenAgentDirectory(agentID string) (string, string, error) {
-	if agentID == "" || agentID == "." || agentID == ".." || filepath.IsAbs(agentID) || filepath.Base(agentID) != agentID {
-		return "", "", fmt.Errorf("agent_id must be a single non-empty path segment")
-	}
 	runtimeRoot, err := qwenRuntimeRoot()
 	if err != nil {
 		return "", "", err
 	}
-	return runtimeRoot, filepath.Join(runtimeRoot, agentID), nil
+	agentDirectory, err := ResolveAgentRuntimeDirectory(agentID)
+	if err != nil {
+		return "", "", err
+	}
+	return runtimeRoot, agentDirectory, nil
 }
 
 func prepareQwenInstallationChanges(

cmd/elydora/plugins/runtime_paths.go

@@ -0,0 +1,128 @@
+package plugins
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+)
+
+var windowsDeviceName = regexp.MustCompile(
+	`(?i)^(?:con|prn|aux|nul|com[1-9¹²³]|lpt[1-9¹²³])(?:\.|$)`,
+)
+
+// AgentRuntimeRoot returns the local root for all Elydora agent runtimes.
+func AgentRuntimeRoot() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home directory: %w", err)
+	}
+	root, err := filepath.Abs(filepath.Join(home, ".elydora"))
+	if err != nil {
+		return "", fmt.Errorf("resolve Elydora runtime root: %w", err)
+	}
+	return root, nil
+}
+
+// ResolveAgentRuntimeDirectory confines an agent ID to one portable path segment.
+func ResolveAgentRuntimeDirectory(agentID string) (string, error) {
+	if invalidAgentDirectoryName(agentID) {
+		return "", fmt.Errorf(
+			"invalid agent ID for local storage: %q must be a single non-empty path segment with a portable file name",
+			agentID,
+		)
+	}
+	root, err := AgentRuntimeRoot()
+	if err != nil {
+		return "", err
+	}
+	candidate := filepath.Join(root, agentID)
+	relative, err := filepath.Rel(root, candidate)
+	if err != nil {
+		return "", fmt.Errorf("resolve agent runtime path for %q: %w", agentID, err)
+	}
+	if relative == "." || relative == ".." || filepath.IsAbs(relative) ||
+		strings.HasPrefix(relative, ".."+string(os.PathSeparator)) ||
+		strings.ContainsRune(relative, os.PathSeparator) {
+		return "", fmt.Errorf("agent ID escapes the local storage directory: %q", agentID)
+	}
+	if _, err := RequirePhysicalDirectory(root); err != nil {
+		return "", err
+	}
+	if _, err := RequirePhysicalDirectory(candidate); err != nil {
+		return "", err
+	}
+	return candidate, nil
+}
+
+func invalidAgentDirectoryName(agentID string) bool {
+	if agentID == "" || agentID == "." || agentID == ".." ||
+		strings.ContainsAny(agentID, `<>:"/\|?*`) ||
+		strings.HasPrefix(agentID, " ") || strings.HasSuffix(agentID, ".") ||
+		strings.HasSuffix(agentID, " ") ||
+		windowsDeviceName.MatchString(agentID) {
+		return true
+	}
+	for _, character := range agentID {
+		if character <= 31 {
+			return true
+		}
+	}
+	return false
+}
+
+// EnsurePrivateDirectory creates an owner-only physical directory.
+func EnsurePrivateDirectory(path string) error {
+	if err := os.MkdirAll(path, 0700); err != nil {
+		return fmt.Errorf("create private directory %s: %w", path, err)
+	}
+	info, err := os.Lstat(path)
+	if err != nil {
+		return fmt.Errorf("inspect private directory %s: %w", path, err)
+	}
+	if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
+		return fmt.Errorf("private directory path is not a physical directory: %s", path)
+	}
+	if runtime.GOOS != "windows" {
+		if err := os.Chmod(path, 0700); err != nil {
+			return fmt.Errorf("restrict private directory %s: %w", path, err)
+		}
+	}
+	return nil
+}
+
+// PrepareAgentRuntimeDirectory validates and creates the private runtime path.
+func PrepareAgentRuntimeDirectory(agentID string) (string, error) {
+	root, err := AgentRuntimeRoot()
+	if err != nil {
+		return "", err
+	}
+	agentDirectory, err := ResolveAgentRuntimeDirectory(agentID)
+	if err != nil {
+		return "", err
+	}
+	if err := EnsurePrivateDirectory(root); err != nil {
+		return "", err
+	}
+	if err := EnsurePrivateDirectory(agentDirectory); err != nil {
+		return "", err
+	}
+	return agentDirectory, nil
+}
+
+// RequirePhysicalDirectory reports whether a path is an existing physical directory.
+func RequirePhysicalDirectory(path string) (bool, error) {
+	info, err := os.Lstat(path)
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	if err != nil {
+		return false, fmt.Errorf("inspect agent runtime directory %s: %w", path, err)
+	}
+	if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
+		return false, fmt.Errorf("agent runtime path is not a physical directory: %s", path)
+	}
+	return true, nil
+}

cmd/elydora/plugins/runtime_paths_test.go

@@ -0,0 +1,95 @@
+package plugins
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func setRuntimeTestHome(t *testing.T) string {
+	t.Helper()
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("USERPROFILE", home)
+	return home
+}
+
+func TestResolveAgentRuntimeDirectoryRejectsUnsafePortableNames(t *testing.T) {
+	setRuntimeTestHome(t)
+	invalid := []string{
+		"../escape",
+		`..\escape`,
+		"C:escape",
+		"agent.",
+		"agent ",
+		" agent",
+		"CON",
+		"COM¹.log",
+		".",
+		"..",
+	}
+	for _, agentID := range invalid {
+		t.Run(agentID, func(t *testing.T) {
+			_, err := ResolveAgentRuntimeDirectory(agentID)
+			if err == nil || !strings.Contains(err.Error(), "invalid agent ID") {
+				t.Fatalf("ResolveAgentRuntimeDirectory(%q) error = %v", agentID, err)
+			}
+		})
+	}
+}
+
+func TestPrepareAgentRuntimeDirectoryCreatesPrivatePhysicalChild(t *testing.T) {
+	home := setRuntimeTestHome(t)
+	agentDirectory, err := PrepareAgentRuntimeDirectory("agent-1")
+	if err != nil {
+		t.Fatalf("PrepareAgentRuntimeDirectory() error = %v", err)
+	}
+	want := filepath.Join(home, ".elydora", "agent-1")
+	if agentDirectory != want {
+		t.Fatalf("agent directory = %q, want %q", agentDirectory, want)
+	}
+	for _, directory := range []string{filepath.Dir(agentDirectory), agentDirectory} {
+		info, err := os.Lstat(directory)
+		if err != nil {
+			t.Fatalf("Lstat(%q) error = %v", directory, err)
+		}
+		if !info.IsDir() || info.Mode()&os.ModeSymlink != 0 {
+			t.Fatalf("%q is not a physical directory", directory)
+		}
+		if runtime.GOOS != "windows" && info.Mode().Perm() != 0700 {
+			t.Fatalf("%q mode = %o, want 700", directory, info.Mode().Perm())
+		}
+	}
+}
+
+func TestPrepareAgentRuntimeDirectoryRejectsSymlinkRoot(t *testing.T) {
+	home := setRuntimeTestHome(t)
+	target := t.TempDir()
+	root := filepath.Join(home, ".elydora")
+	if err := os.Symlink(target, root); err != nil {
+		t.Skipf("directory symbolic links unavailable: %v", err)
+	}
+	_, err := PrepareAgentRuntimeDirectory("agent-1")
+	if err == nil || !strings.Contains(err.Error(), "physical directory") {
+		t.Fatalf("PrepareAgentRuntimeDirectory() error = %v", err)
+	}
+}
+
+func TestResolveAgentRuntimeDirectoryRejectsSymlinkChild(t *testing.T) {
+	home := setRuntimeTestHome(t)
+	root := filepath.Join(home, ".elydora")
+	if err := os.MkdirAll(root, 0700); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
+	}
+	target := t.TempDir()
+	link := filepath.Join(root, "agent-1")
+	if err := os.Symlink(target, link); err != nil {
+		t.Skipf("directory symbolic links unavailable: %v", err)
+	}
+	_, err := ResolveAgentRuntimeDirectory("agent-1")
+	if err == nil || !strings.Contains(err.Error(), "physical directory") {
+		t.Fatalf("ResolveAgentRuntimeDirectory() error = %v", err)
+	}
+}