阻止任意文件下载漏洞

ruoyi-admin/src/main/java/com/ruoyi/web/controller/common/CommonController.java

@@ -5,6 +5,7 @@ import javax.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -41,17 +42,15 @@ public class CommonController
     {
         try
         {
-            if (!FileUtils.isValidFilename(fileName))
+            if (!FileUtils.checkAllowDownload(fileName))
             {
                 throw new Exception(StringUtils.format("文件名称({})非法，不允许下载。 ", fileName));
             }
             String realFileName = System.currentTimeMillis() + fileName.substring(fileName.indexOf("_") + 1);
             String filePath = RuoYiConfig.getDownloadPath() + fileName;
 
-            response.setCharacterEncoding("utf-8");
-            response.setContentType("multipart/form-data");
-            response.setHeader("Content-Disposition",
-                    "attachment;fileName=" + FileUtils.setFileDownloadHeader(request, realFileName));
+            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
+            FileUtils.setAttachmentResponseHeader(response, realFileName);
             FileUtils.writeBytes(filePath, response.getOutputStream());
             if (delete)
             {
@@ -92,18 +91,28 @@ public class CommonController
      * 本地资源通用下载
      */
     @GetMapping("/common/download/resource")
-    public void resourceDownload(String name, HttpServletRequest request, HttpServletResponse response) throws Exception
+    public void resourceDownload(String resource, HttpServletRequest request, HttpServletResponse response)
+            throws Exception
     {
+        try
+        {
+            if (!FileUtils.checkAllowDownload(resource))
+            {
+                throw new Exception(StringUtils.format("资源文件({})非法，不允许下载。 ", resource));
+            }
             // 本地资源路径
             String localPath = RuoYiConfig.getProfile();
             // 数据库资源地址
-        String downloadPath = localPath + StringUtils.substringAfter(name, Constants.RESOURCE_PREFIX);
+            String downloadPath = localPath + StringUtils.substringAfter(resource, Constants.RESOURCE_PREFIX);
             // 下载名称
             String downloadName = StringUtils.substringAfterLast(downloadPath, "/");
-        response.setCharacterEncoding("utf-8");
-        response.setContentType("multipart/form-data");
-        response.setHeader("Content-Disposition",
-                "attachment;fileName=" + FileUtils.setFileDownloadHeader(request, downloadName));
+            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
+            FileUtils.setAttachmentResponseHeader(response, downloadName);
             FileUtils.writeBytes(downloadPath, response.getOutputStream());
         }
+        catch (Exception e)
+        {
+            log.error("下载文件失败", e);
+        }
+    }
 }

ruoyi-common/src/main/java/com/ruoyi/common/utils/file/FileTypeUtils.java

@@ -0,0 +1,47 @@
+package com.ruoyi.common.utils.file;
+
+import java.io.File;
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * 文件类型工具类
+ *
+ * @author ruoyi
+ */
+public class FileTypeUtils
+{
+    /**
+     * 获取文件类型
+     * <p>
+     * 例如: ruoyi.txt, 返回: txt
+     * 
+     * @param file 文件名
+     * @return 后缀（不含".")
+     */
+    public static String getFileType(File file)
+    {
+        if (null == file)
+        {
+            return StringUtils.EMPTY;
+        }
+        return getFileType(file.getName());
+    }
+
+    /**
+     * 获取文件类型
+     * <p>
+     * 例如: ruoyi.txt, 返回: txt
+     *
+     * @param fileName 文件名
+     * @return 后缀（不含".")
+     */
+    public static String getFileType(String fileName)
+    {
+        int separatorIndex = fileName.lastIndexOf(".");
+        if (separatorIndex < 0)
+        {
+            return "";
+        }
+        return fileName.substring(separatorIndex + 1).toLowerCase();
+    }
+}

ruoyi-common/src/main/java/com/ruoyi/common/utils/file/FileUtils.java

@@ -7,7 +7,11 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
 import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import org.apache.commons.lang3.ArrayUtils;
+import com.ruoyi.common.utils.StringUtils;
 
 /**
  * 文件处理工具类
@@ -104,6 +108,30 @@ public class FileUtils extends org.apache.commons.io.FileUtils
         return filename.matches(FILENAME_PATTERN);
     }
 
+    /**
+     * 检查文件是否可下载
+     * 
+     * @param resource 需要下载的文件
+     * @return true 正常 false 非法
+     */
+    public static boolean checkAllowDownload(String resource)
+    {
+        // 禁止目录上跳级别
+        if (StringUtils.contains(resource, ".."))
+        {
+            return false;
+        }
+
+        // 检查允许下载的文件规则
+        if (ArrayUtils.contains(MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION, FileTypeUtils.getFileType(resource)))
+        {
+            return true;
+        }
+
+        // 不在允许下载的文件规则
+        return false;
+    }
+
     /**
      * 下载文件名重新编码
      * 
@@ -111,8 +139,7 @@ public class FileUtils extends org.apache.commons.io.FileUtils
      * @param fileName 文件名
      * @return 编码后的文件名
      */
-    public static String setFileDownloadHeader(HttpServletRequest request, String fileName)
-            throws UnsupportedEncodingException
+    public static String setFileDownloadHeader(HttpServletRequest request, String fileName) throws UnsupportedEncodingException
     {
         final String agent = request.getHeader("USER-AGENT");
         String filename = fileName;
@@ -139,4 +166,38 @@ public class FileUtils extends org.apache.commons.io.FileUtils
         }
         return filename;
     }
+
+    /**
+     * 下载文件名重新编码
+     *
+     * @param response 响应对象
+     * @param realFileName 真实文件名
+     * @return
+     */
+    public static void setAttachmentResponseHeader(HttpServletResponse response, String realFileName) throws UnsupportedEncodingException
+    {
+        String percentEncodedFileName = percentEncode(realFileName);
+
+        StringBuilder contentDispositionValue = new StringBuilder();
+        contentDispositionValue.append("attachment; filename=")
+                .append(percentEncodedFileName)
+                .append(";")
+                .append("filename*=")
+                .append("utf-8''")
+                .append(percentEncodedFileName);
+
+        response.setHeader("Content-disposition", contentDispositionValue.toString());
+    }
+
+    /**
+     * 百分号编码工具方法
+     *
+     * @param s 需要百分号编码的字符串
+     * @return 百分号编码后的字符串
+     */
+    public static String percentEncode(String s) throws UnsupportedEncodingException
+    {
+        String encode = URLEncoder.encode(s, StandardCharsets.UTF_8.toString());
+        return encode.replaceAll("\\+", "%20");
+    }
 }