fix: harden authentication and file access security

back/services/log.ts

@@ -1,3 +1,4 @@
+import { resolveFileAccess } from '../shared/fileAccess';
 import path from 'path';
 import { Inject, Service } from 'typedi';
 import winston from 'winston';
@@ -8,7 +9,10 @@ export default class LogService {
   constructor(@Inject('logger') private logger: winston.Logger) {}
 
   public checkFilePath(filePath: string, fileName: string) {
-    const finalPath = path.resolve(config.logPath, filePath, fileName);
-    return finalPath.startsWith(config.logPath) ? finalPath : '';
+    return resolveFileAccess(
+      config.logPath,
+      [filePath || '', fileName],
+      config.blackFileList,
+    );
   }
 }