I have an ASP.Net application running in IIS which creates a file in a specified location using CsvWriter. If I use the full UNC path I get error that Access to the path is denied, however if I use Drive letter it works fine. What is puzzling me is that it does work with UNC path in development environment.
This code which creates the file
using (var writer = new StreamWriter(fileName))
using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
{
csv.WriteField("Foo");
csv.WriteField("Bar");
csv.NextRecord();
}
Following advice various posts such as Access to the path is denied and IIS7 Permissions Overview - ApplicationPoolIdentity and MS Documentation: Application Pool Identities. I was initially convinced my problem was security related. This was supported by the fact that the application would run perfectly in development environment (IIS Express) which uses my user credentials but not under IIS which uses Application Pool Identity. I gave MyApplicationPoolIdentity full access to the specific directory to no avail.
However, I discovered that if I use the drive letter (C:\myDirectory\mySubDirectory\myFile.csv) as opposed to the UNC path (\\myServer\myDirectory\mySubDirectory\myFile.csv) in production the file is created perfectly. Even though I have the application working my concern is that I may have some configuration issue with IIS or my server which may bite me later. So my question is what would cause the create file/write to fail using UNC path and not using Drive letter?
I am using Windows Server 2016.
Thanks
Tony
I think it is caused by permission issues. First, did you get any related error messages? Or you can try the following methods：
1.you can use Process Monitor to see which account is being used to access the share and what permission are required.
2.Check to ensure the account that IIS is running under has needed rights to the troublesome UNC.
Related
Im having trouble with writing files to remote directory via network. The following code fails when I try to check if the directory exists:
if (!Directory.Exists(processingPath))
Directory.CreateDirectory(processingPath);
processingPath is composed like
processingPath = xxxObject.serverPath + "processing\\";
xxxObject.serverPath contains something like this
\\machineNetworkName\sharedFolder\
Its working properly, but when many requests are processing (running as tasks asynchronously), it stops working and failing into exception:
System.IO.IOException: The network path was not found.
Could you please help me what could be the problem and why it is failing after some time on network path???
Thanks for your solutions
I got the same error before, it was about authentication problems.
You have to be sure that you set properly the user on IIS, because it use a Default App Pool's identity which can't access to your NFS.
You can also use IIS virtual folders to set the identity.
(on IIS manager, see App Pool settings -> Identity and also virtual folders settings -> identity).
In my case, it worked better by using the Impersonation directly in the code, so I recommend you to use the VladL WrappedImpersonationContext Object: How to provide user name and password when connecting to a network share
Last thing to check, the owner of the files on your NFS server, if they were created under the root user, it might not work.
I had the same problem and solved it. The problem in my code and I see it in yours, too, is that you have the slash at the end of the network path.
Instead of processingPath = xxxObject.serverPath + "processing\\"; write: processingPath = xxxObject.serverPath + "processing";
I want to read file names of pdfs from a folder on a network share that match certain parameters and provide a link to view them on a details page for my model. All I need to get is the file name. I don't need any file management/read/write at this time.
I'm able to display a .pdf in the browser if I have the path (IE will open "file://" links). The part I'm missing is getting file names from the remote (but same domain) directory at run-time.
We've set up a virtual directory for the app to use and that has worked fine in the past if the resolved physical folder is on the same server, but that is not the case here.
I've tried Impersonation, but that doesn't seem to work as I'm still getting an access is denied error.
I realize this would probably be a security issue and is why it isn't allowed, but is there an IIS configuration or other avenue that needs to be set-up to allow this? I can't seem to find a way with just code that opens the directory for reading.
Example code of how I might normally read some info from one file in a virtual directory:
// This example code is inside a controller action, so Server refers to HttpContextBase
var path = Server.MapPath("~/MyVirtualDirectory/" + fileName);
var fileExists = System.IO.File.Exists(path);
var fileLastModified = System.IO.File.LastWriteTime(path);
To enumerate over matching files in a directory, I've used DirectoryInfo
var pdfFileNames = new List<string>();
var dir = new DirectoryInfo(Server.MapPath("~/VirtualDirectory/"));
var pdfs = dir.EnumerateFiles("*.pdf");
foreach (var pdf in pdfs)
{
pdfFileNames.Add(pdf.Name);
}
As I mentioned, these methods work fine when the physical folder is on the same server, but once the directory is on a remote drive, then it no longer works. I have permissions to open the desired directory and my collegue said he gave the appropriate permissions to the virtual directory and server. Not sure what else to try at this point.
Edit: Now that it is working, I display the files using the Virtual Directory
http://server/appName/virtualDirectory/pdfFileName
By default, IIS application pools run under a specific local Windows identity named IIS APPPOOL\[NameOfYourAppPool]. This is a local user and it will not be possible to grant permissions to this identity to access resources located on a different machine.
If both servers are inside the same domain, you can try the following solutions:
Run the IIS application under a domain user and grant the required permissions to this domain user.
Run the IIS application under the NetworkService identity and grant permissions to the DOMAIN\MACHINENAME$ account of the IIS server.
I have developed a windows service using local system as Account. I have used
network path of file
FileInfo fi = new FileInfo(#"\\epm-server\penDocuments_LabMeds\" + Convert.ToString(dr["mrn"]) + "\\SyncedXML\\" + Convert.ToString(dr["xmlfile"]));
if (!fi.Exists)
boolFileNotFound = true;
A dynamic path of a file that is built from database.
It works fine when I run Windows Service in Debug Mode, but when I install it then fileNotExists returns TRUE always like the file doesnt exist but infact it does exist.
This is bugging me a lot now. Kindly help me why its not working. Its a server path. Its getting opened in my PC.
Thanks
Did you notice the double backslashes in front and after SyncedXML (\\SyncedXML\\)?
This is probably the cause of your error.
Additionally I'd use string.Format in such cases to reduce the inadvertently addition of unwanted characters:
var path = string.Format(#"\\epm-server\penDocuments_LabMeds\{0}\SyncedXML\{1}", dr[mrn], dr[xmlfile]);
var fi = new FileInfo(path);
Edit:
If it's permission-related, then it's very likely that your local system account (in whose context the service is running) isn't allowed to access the epm-server.
The path is accessible if you're opening it directly or if you're running the service in debug mode as this is happening in your user context (e.g. YOURDOMAIN\vickyshazad), and you're allowed to access the ressource, whereas NT AUTHORITY\SYSTEM is not.
It's usually a good practise to have a special service account for your developed windows service and grant this user only and exactly the required permissions (least privilege). Maybe ask your system administrator for a service user.
Local System (NT AUTHORITY\SYSTEM) is a highly privileged account that's not recommended to use in general (see MSDN).
Most services do not need such a high privilege level. If your service does not need these privileges, and it is not an interactive service, consider using the LocalService account or the NetworkService account.
I am trying to create a file on the remote machine but I am getting The "Network name cannot be found". I checked the network path and I was able to access the path from my machine. Could you please let me know what could be wrong?
Here is my code.
using (StreamWriter sw = new StreamWriter("\\\\servername\\TEST1\\TEST\\NEWFILE.csv", true))
{
sw.WriteLine(sw);
}
Go to \servername\TEST1 and give write permission to the user or aspnet (if you have a web application) on test folder and then re-run your program. It will work.
To give write permissions, just refer to this article:
How to share a folder/File
In case it still does not work, replace servername with server IP address and do the same as stated above.
Give the access rights to the user under which this application runs either it is a IIS pool or windows service etc
it is surely a security isssue. you need to give Write access to the remote machine
While I am trying to upload a registry in my registries using the C# code , the application is throwing the error "a required privilege is not held by the client". If I am using the same code on some other machine it is working fine but not particularly on my machine
I am using below mentioned code to upload the registry files
Process my_p = new Process();
my_p.StartInfo.FileName = "reg";
my_p.StartInfo.Arguments = "load HKLM\TEST C:\Documents and Settings\Administrator\NTUSER.DAT";
my_p.Start();
my_p.WaitForExit();
System.IO.StreamReader srOutPut = my_p.StandardOutput;
System.IO.StreamReader srError = my_p.StandardError;
my_p.Close();
results = srOutPut.ReadToEnd().Trim();
Errors = srError.ReadToEnd().Trim();
Moreover One thing I have noticed that the above code I am using in http based web site, but when I am using it in a File Syatem based web site it is working fine. Please help I am not getting the error.
Regards,
Vikram
You can load RegLoadKey function directly to load the hive as a subkey. Another API is RegLoadAppKey but it works only starting from Windows Vista. Different versions of Reg.exe use the API. How you can read in the description the RegLoadKey you need have SE_RESTORE_NAME and SE_BACKUP_NAME privileges and enable these (see http://msdn.microsoft.com/en-us/library/ms717797.aspx). If you are in the Group of Administrators or Backup Operators you have these privileges. One more problem can be if Reg.exe use RegLoadKey function and you have a local administrative rights, but you start on Vista or Windows 7 a command without admin rights because of UAC (User Account Control).