fix(security): validate auth file names to prevent unsafe input

internal/api/handlers/management/auth_files.go

@@ -541,10 +541,23 @@ func isRuntimeOnlyAuth(auth *coreauth.Auth) bool {
 	return strings.EqualFold(strings.TrimSpace(auth.Attributes["runtime_only"]), "true")
 }
 
+func isUnsafeAuthFileName(name string) bool {
+	if strings.TrimSpace(name) == "" {
+		return true
+	}
+	if strings.ContainsAny(name, "/\\") {
+		return true
+	}
+	if filepath.VolumeName(name) != "" {
+		return true
+	}
+	return false
+}
+
 // Download single auth file by name
 func (h *Handler) DownloadAuthFile(c *gin.Context) {
-	name := c.Query("name")
-	if name == "" || strings.Contains(name, string(os.PathSeparator)) {
+	name := strings.TrimSpace(c.Query("name"))
+	if isUnsafeAuthFileName(name) {
 		c.JSON(400, gin.H{"error": "invalid name"})
 		return
 	}
@@ -626,8 +639,8 @@ func (h *Handler) UploadAuthFile(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "no files uploaded"})
 		return
 	}
-	name := c.Query("name")
-	if name == "" || strings.Contains(name, string(os.PathSeparator)) {
+	name := strings.TrimSpace(c.Query("name"))
+	if isUnsafeAuthFileName(name) {
 		c.JSON(400, gin.H{"error": "invalid name"})
 		return
 	}
@@ -860,7 +873,7 @@ func uniqueAuthFileNames(names []string) []string {
 
 func (h *Handler) deleteAuthFileByName(ctx context.Context, name string) (string, int, error) {
 	name = strings.TrimSpace(name)
-	if name == "" || strings.Contains(name, string(os.PathSeparator)) {
+	if isUnsafeAuthFileName(name) {
 		return "", http.StatusBadRequest, fmt.Errorf("invalid name")
 	}
 

internal/api/handlers/management/auth_files_download_test.go

@@ -0,0 +1,62 @@
+package management
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+)
+
+func TestDownloadAuthFile_ReturnsFile(t *testing.T) {
+	t.Setenv("MANAGEMENT_PASSWORD", "")
+	gin.SetMode(gin.TestMode)
+
+	authDir := t.TempDir()
+	fileName := "download-user.json"
+	expected := []byte(`{"type":"codex"}`)
+	if err := os.WriteFile(filepath.Join(authDir, fileName), expected, 0o600); err != nil {
+		t.Fatalf("failed to write auth file: %v", err)
+	}
+
+	h := NewHandlerWithoutConfigFilePath(&config.Config{AuthDir: authDir}, nil)
+
+	rec := httptest.NewRecorder()
+	ctx, _ := gin.CreateTestContext(rec)
+	ctx.Request = httptest.NewRequest(http.MethodGet, "/v0/management/auth-files/download?name="+url.QueryEscape(fileName), nil)
+	h.DownloadAuthFile(ctx)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("expected download status %d, got %d with body %s", http.StatusOK, rec.Code, rec.Body.String())
+	}
+	if got := rec.Body.Bytes(); string(got) != string(expected) {
+		t.Fatalf("unexpected download content: %q", string(got))
+	}
+}
+
+func TestDownloadAuthFile_RejectsPathSeparators(t *testing.T) {
+	t.Setenv("MANAGEMENT_PASSWORD", "")
+	gin.SetMode(gin.TestMode)
+
+	h := NewHandlerWithoutConfigFilePath(&config.Config{AuthDir: t.TempDir()}, nil)
+
+	for _, name := range []string{
+		"../external/secret.json",
+		`..\\external\\secret.json`,
+		"nested/secret.json",
+		`nested\\secret.json`,
+	} {
+		rec := httptest.NewRecorder()
+		ctx, _ := gin.CreateTestContext(rec)
+		ctx.Request = httptest.NewRequest(http.MethodGet, "/v0/management/auth-files/download?name="+url.QueryEscape(name), nil)
+		h.DownloadAuthFile(ctx)
+
+		if rec.Code != http.StatusBadRequest {
+			t.Fatalf("expected %d for name %q, got %d with body %s", http.StatusBadRequest, name, rec.Code, rec.Body.String())
+		}
+	}
+}

internal/api/handlers/management/auth_files_download_windows_test.go

@@ -0,0 +1,51 @@
+//go:build windows
+
+package management
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+)
+
+func TestDownloadAuthFile_PreventsWindowsSlashTraversal(t *testing.T) {
+	t.Setenv("MANAGEMENT_PASSWORD", "")
+	gin.SetMode(gin.TestMode)
+
+	tempDir := t.TempDir()
+	authDir := filepath.Join(tempDir, "auth")
+	externalDir := filepath.Join(tempDir, "external")
+	if err := os.MkdirAll(authDir, 0o700); err != nil {
+		t.Fatalf("failed to create auth dir: %v", err)
+	}
+	if err := os.MkdirAll(externalDir, 0o700); err != nil {
+		t.Fatalf("failed to create external dir: %v", err)
+	}
+
+	secretName := "secret.json"
+	secretPath := filepath.Join(externalDir, secretName)
+	if err := os.WriteFile(secretPath, []byte(`{"secret":true}`), 0o600); err != nil {
+		t.Fatalf("failed to write external file: %v", err)
+	}
+
+	h := NewHandlerWithoutConfigFilePath(&config.Config{AuthDir: authDir}, nil)
+
+	rec := httptest.NewRecorder()
+	ctx, _ := gin.CreateTestContext(rec)
+	ctx.Request = httptest.NewRequest(
+		http.MethodGet,
+		"/v0/management/auth-files/download?name="+url.QueryEscape("../external/"+secretName),
+		nil,
+	)
+	h.DownloadAuthFile(ctx)
+
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("expected status %d, got %d with body %s", http.StatusBadRequest, rec.Code, rec.Body.String())
+	}
+}