用户具有读取权限的列表文件(ASP.NET)

时间:2010-02-05 18:02:46

标签: c# asp.net security unauthorized windows-identity

我想列出用户具有读取权限的文件夹中的所有文件。用户访问网站,可以使用表单身份验证的一些方面(例如添加链接等),但我想使用他们的Windows凭据列出给定文件夹中的文件(因为我关闭了匿名访问),隐藏他们无法阅读。

但是,使用Directory.GetFiles时,它还包含无法读取的文件(尽管可以读取元数据(文件大小,创建日期等))。

这就是我所拥有的:

string[] files;
string[] folders;
string rootDir = @"\\server\path\to\dir\";
WindowsIdentity id = (WindowsIdentity)User.Identity ;
using (System.Security.Principal.WindowsImpersonationContext context = System.Security.Principal.WindowsIdentity.Impersonate(id.Token))
{
        files = Directory.GetFiles(rootDir);
        folders = Directory.GetDirectories(rootDir);

        foreach (string file in files)
        {
            FileInfo fi = new FileInfo(file);
            FileSecurity fs = fi.GetAccessControl(AccessControlSections.Access);
            //foreach (FileSystemAccessRule rule in fs.GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier)))
            //{
            //  Response.Write((FileSystemRights.Read & rule.FileSystemRights) + " <br />");
            //}

            Response.Write(file + " " + fi.Length + "<br />");
        }
        context.Undo();
}

当我访问该页面时,即使它应该使用当前用户凭据,我也会在使用UnauthorizedAccessException后立即获得GetAccessControl。取消using失败,因为asp.net帐户无权访问该文件夹。当FileSecurity被注释掉时,它会列出所有文件。

堆栈追踪:

[UnauthorizedAccessException: Attempted to perform an unauthorized operation.]
   System.Security.AccessControl.Win32.GetSecurityInfo(ResourceType resourceType, String name, SafeHandle handle, AccessControlSections accessControlSections, RawSecurityDescriptor& resultSd) +697
   System.Security.AccessControl.NativeObjectSecurity.CreateInternal(ResourceType resourceType, Boolean isContainer, String name, SafeHandle handle, AccessControlSections includeSections, Boolean createByName, ExceptionFromErrorCode exceptionFromErrorCode, Object exceptionContext) +63
   System.Security.AccessControl.FileSystemSecurity..ctor(Boolean isContainer, String name, AccessControlSections includeSections, Boolean isDirectory) +86
   System.Security.AccessControl.FileSecurity..ctor(String fileName, AccessControlSections includeSections) +42
   System.IO.FileInfo.GetAccessControl(AccessControlSections includeSections) +29
   UNCDirectory.Page_Load(Object sender, EventArgs e) +213
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

有关如何执行此操作的任何想法,而不是尝试打开每个文件并捕获发生的异常?

2 个答案:

答案 0 :(得分:2)

管理修复它。当您拒绝读取文件时,它也会拒绝读取权限,因此会UnauthorizedAccessException。所以使用try... catch ...似乎是唯一的选择。

如果Read被拒绝且允许ReadPermissions(在高级设置下完成),则可以防止异常。这处理两个:

string[] files;
string[] folders;
WindowsIdentity id = (WindowsIdentity)User.Identity;
using (System.Security.Principal.WindowsImpersonationContext context = id.Impersonate())
{
    files = Directory.GetFiles(RootDir);
    folders = Directory.GetDirectories(RootDir);

    foreach (string file in files)
    {
        FileInfo fi = new FileInfo(file);
        FileSecurity fs = null;
        try
        {
            fs = fi.GetAccessControl(AccessControlSections.Access);
        }
        catch (UnauthorizedAccessException)
        {
            goto Next;
        }
        foreach (FileSystemAccessRule rule in fs.GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier)))
        {
            if (id.User.CompareTo(rule.IdentityReference as SecurityIdentifier) == 0)
            {
                if(rule.AccessControlType.ToString() == "Deny" &&
                    rule.FileSystemRights.ToString().Contains("ReadData"))
                {
                    goto Next;
                }
            }
        }

        Response.Write(file + " " + fi.Length + "<br />");
        // next in sequence. label for goto
        Next: ;
    }
    context.Undo();
}

现在文件可以列在任何目录中(使用模拟),也不需要提供ASP.NET帐户(通常是网络服务)访问。

答案 1 :(得分:1)

您可能需要在asp.net/IIS中设置Windows /集成身份验证。 http://msdn.microsoft.com/en-us/library/aa292114(VS.71).aspx