ファイル名の上限を拡大し、動画の配信・削除を os.Root に置き換え（エピソード ID は 64 バイト上限）

internal/web/library.go

@@ -7,7 +7,6 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
-	"strings"
 
 	"gitea.kazu634.com/kazu634/tver/internal/store"
 	"github.com/jackc/pgx/v5"
@@ -76,12 +75,13 @@ func (s *server) serveVideo(w http.ResponseWriter, r *http.Request) {
 		}
 		return
 	}
-	path, err := secureVideoPath(s.videoDir, *job.FilePath, true)
+	root, err := os.OpenRoot(s.videoDir)
 	if err != nil {
 		http.NotFound(w, r)
 		return
 	}
-	file, err := os.Open(path)
+	defer root.Close()
+	file, err := root.Open(*job.FilePath)
 	if err != nil {
 		http.NotFound(w, r)
 		return
@@ -93,7 +93,7 @@ func (s *server) serveVideo(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	w.Header().Set("Content-Type", "video/mp4")
-	http.ServeContent(w, r, filepath.Base(path), info.ModTime(), file)
+	http.ServeContent(w, r, filepath.Base(*job.FilePath), info.ModTime(), file)
 }
 
 func (s *server) deleteVideo(w http.ResponseWriter, r *http.Request) {
@@ -102,12 +102,24 @@ func (s *server) deleteVideo(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if job.FilePath != nil {
-		path, err := secureVideoPath(s.videoDir, *job.FilePath, false)
+		if !filepath.IsLocal(*job.FilePath) {
+			http.Error(w, "動画ファイルの場所が不正です", http.StatusConflict)
+			return
+		}
+		root, err := os.OpenRoot(s.videoDir)
 		if err != nil {
 			http.Error(w, "動画ファイルの場所が不正です", http.StatusConflict)
 			return
 		}
-		if err := os.Remove(path); err != nil && !errors.Is(err, os.ErrNotExist) {
+		defer root.Close()
+		file, err := root.Open(*job.FilePath)
+		if err == nil {
+			_ = file.Close()
+		} else if !errors.Is(err, os.ErrNotExist) {
+			http.Error(w, "動画ファイルの場所が不正です", http.StatusConflict)
+			return
+		}
+		if err := root.Remove(*job.FilePath); err != nil && !errors.Is(err, os.ErrNotExist) {
 			s.logger.Printf("動画ファイルの削除に失敗: %v", err)
 			http.Error(w, "動画ファイルを削除できませんでした", http.StatusInternalServerError)
 			return
@@ -139,57 +151,3 @@ func (s *server) succeededJob(w http.ResponseWriter, r *http.Request) (store.Job
 	}
 	return job, true
 }
-
-func secureVideoPath(root, relative string, mustExist bool) (string, error) {
-	if relative == "" || filepath.IsAbs(relative) {
-		return "", errors.New("video path must be relative")
-	}
-	clean := filepath.Clean(relative)
-	if clean == "." || clean == ".." || strings.HasPrefix(clean, ".."+string(filepath.Separator)) {
-		return "", errors.New("video path leaves root")
-	}
-	rootAbs, err := filepath.Abs(root)
-	if err != nil {
-		return "", err
-	}
-	rootReal, err := filepath.EvalSymlinks(rootAbs)
-	if err != nil {
-		return "", err
-	}
-	candidate := filepath.Join(rootAbs, clean)
-	if err := insideRoot(rootAbs, candidate); err != nil {
-		return "", err
-	}
-	resolved, err := filepath.EvalSymlinks(candidate)
-	if err == nil {
-		if err := insideRoot(rootReal, resolved); err != nil {
-			return "", err
-		}
-		return candidate, nil
-	}
-	if mustExist || !errors.Is(err, os.ErrNotExist) {
-		return "", err
-	}
-	ancestor := filepath.Dir(candidate)
-	for {
-		resolvedAncestor, evalErr := filepath.EvalSymlinks(ancestor)
-		if evalErr == nil {
-			if err := insideRoot(rootReal, resolvedAncestor); err != nil {
-				return "", err
-			}
-			return candidate, nil
-		}
-		if !errors.Is(evalErr, os.ErrNotExist) || ancestor == rootAbs {
-			return "", evalErr
-		}
-		ancestor = filepath.Dir(ancestor)
-	}
-}
-
-func insideRoot(root, path string) error {
-	rel, err := filepath.Rel(root, path)
-	if err != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
-		return errors.New("path leaves video root")
-	}
-	return nil
-}