I'm trying to get my MVC app to write a simple text file to another server using System.IO.File.WriteAllText. (A separate process is looking in that folder for text files to grab.) It works fine when debugging on my local machine, but when deployed to IIS on a test server, I always get this error when trying to write the file:
Access to the path '\\server\C$\folder\subfolder\file.txt' is denied.
The answer to at least half a dozen similar questions here on SO was to give the application pool identity account access to that folder. However, the app pool on IIS was already running under a service account that had full permissions to the desired folder but was still getting the error. I even tried changing the app pool to my own account (the one used successfully in debugging) and still get the error.
Anonymous access is turned off, and Windows Authentication is turned on (part of the file.txt is info from the user's AD account). I have tried accessing the app with several AD accounts, both with and without access to \\server\C$\folder\subfolder\ but they all give the same error.
I don't see how the app can be running under an authorized account, and the user can be logged in to the app with an authorized account, but still get the access denied error. Is there any way to get more info about specifically what access is denied or which account is actually being denied? Anything else I'm missing here??
You need to check whether other processes already have the file open, e.g, "A separate process is looking in that folder for text files to grab" - perhaps this separate process already has the file open and is therefore locking out your IIS process? Use Process Monitor (https://learn.microsoft.com/en-us/sysinternals/downloads/procmon) to monitor activity on the file.
Also you give the file location as '\server\C$\folder\subfolder\file.txt'. UNC paths normally begin with a '\\', e.g., '\\server\C$\folder\subfolder\file.txt'. That may just be an artefact of StackOverflow escaping the double slash to a single slash.
As a simple test, can you use notepad with your own account to open the file in the error message and write to the file? What if you use the application pool identity account?
Edit: You run Process Monitor on the server that has the file location. Add a Path filter like this:
Path excludes file.txt then Exclude
Where file.txt is the file name (without the directory) of the file you are monitoring. This filter will only capture events for that file and will exclude everything else. Once an event occurs, right click it, and go to Properties, Process to see the User initiating the event.
First of all, you can try to give write rights to IUSR user on your folder in which you want to write your text file.
There is a way to imitate an user in your asp.net application by using Impersonate tag in your web.config file but I think this can be dangerous.
<identity impersonate="true" userName="nomducompte" password="motdepasse" />
I hope this helps.
Related
I've got an MVC site that i've published to a remote server running IIS, but I've got a problem with the site where I can upload documents to a folder (on that server, within the site header folder) via the site, but I get an "Access is denied" error whenever I try to read that same document.
At first I thought it may have been a simple permissions problem, but I checked the security on the folder and it's showing full control to domain users on it, and when I run the project locally through Visual Studio I can open it up without any problems.
I assumed it may be something to do with the context of the site running under IIS, but I don't know if the changes need to be made in IIS or on the folder permissions themselves.
Can someone help?
EDIT
I'm opening the file using Process.Start like:
System.Diagnostics.Process.Start("FilePath");
EDIT 2
I've edited the app pool that the site is running on and set it to allow the process to interact with the desktop, but this has not worked. I have also tried setting the App Pool to load the user profile based on suggestions I found elsewhere but that has not worked either. The only other suggestion i've found is to set the App Pool identity to "Local System", but people have said this is a security risk so I don't want to do this unless necessary.
In my asp.net application, I'm trying to save a file in a different directory but on the same server and I keep getting a "Access to the path '\\12.34.56.78\d$\blah\subdomains\static\httpdocs\images\upload' is denied.
Both sites run under the same application pool on IIS7. I've added modify permissions on the Images folder for IUSR and Network Service and no change. I also added Full control for Everyone on that folder, but still nothing.
Is there something else I need to amend when uploading files to a location on the server that sits outwith the website? Would FTP be a better solution?
Thanks
EDIT Retrying this answer as the original was on a phone and almost unintelligible.
The path you are providing indicates you are trying to create folders and files via UNC path names within your application. This is not advisable. Typically, only members of a local or domain administrators group are going be authorized to access anything through that administrative share, meaning that permission tweaks to lower-level folders won't solve the problem if the core issue is access through the D$ share itself.
If you are attempting to create folders on the same physical machine, I would recommend that you simply use the machine-specific path, eg D:\folder1\folder2\etc, rather than the UNC path. Also, as an additional point (which I"m assuming is simply a typo), the UNC path provided starts with only a single slash, rather than the normal two slashes, eg \\12.34.56.789\D$...
To begin with, I developed a web application which reads an XML file from specific location and displays the contents on editable web page of the application,which is executed perfectly when the XML file is on the same machine/computer. When I try to read the same file on different computer on the network I cannot read the contents onto my web page.
My Observation:
When I access that file from run window in the computer by entering \xxx.xxx.xx.xx\c$ it gives me the window to connect to the machine asking for credentials and I guess the session is open. So I close the window and when I access the xml file from the web application it's able to read the content.
Is there a way to bypass this authentication mechanism which is part of windows when I use my web app to read the XML file or is there a way to accommodate the extra step to configure the authentication in my application?
I would be glad if someone can guide me to the solution.
Check the user your web application is running under and if this user is also permitted to access this location.
If you are using IIS to host the page you have to check the "AppPool" user and also the users which are used at the "Web Site" and "Application"
Just change IIS application pool user to "enough rights" user (right click current app pool - advanced settings - identity) or specify impersonation in the same name section in web.config.
Could it be possible to change your logic,
By storing file from different network to local machine where your code is running, through uploading file and process it.
I use this simple line of code inside my HttpHandler:
Directory.CreateDirectory(#"\\srv-001\dev\folderToCreate\");
I receive an UnauthoridezAccessException telling me that the access to the path is denied.
From here, I create a little Dos application in C# doing the same thing and I was able to create the folder. So, I thought that it might be that IIS is running on a different user than myself. I went to IIS and changed the Application pool to a Custom user, myself. But, unfortunately, I got the same exception.
I have try to create a Share folder on my computer and I can create directory. Also, when debugging I can see that System.Threading.Thread.CurrentPrincipal.Identity have its AuthenticationType to "", IsAuthenticated to false and name to "".
So, with all those tests I can conclude that the HttpHandler that receive the file cannot create a directory because of some security access.
How can I grand access to my HttpHandler to be able to create a directory (and files) to a network folder?
actually, i thought of one other thing to check. not only is there the app pool identity, but there is also an identity associated with anonymous authentication. if you are on iis 7/7.5, you should be able to see the authentication icon for the web application and doubleclick that. selecting anonymous authentication and then clicking edit will reveal a dialog that gives you the option of specifying a user or the app pool user. i bet if you choose app pool user, that will fix it.
if you are on iis 6, i don't recall as clearly, but i'll give it a shot. don't have iis 6 in front of me to verify, but i remember there being an anonymous access button you can click that would bring up a dialog where you could specify the user. don't think you had the option there of using the app pool identity and had to specify the account explicitly.
I have a web service using .net c# and I want to write to a text file on the server, but I cannot get this to work. I believe it's a permission problem.
Specifically, I think the problem is I am using System.IO.Directory.GetCurrentDirectory().
Is there a better alternative?
Try granting the ASP.NET user (or whatever account IIS is running as) permission to write to the folder you are trying to write to.
If this is a network share, try to run IIS as a domain user that can write to the share.
Remember the principle of granting minimal permission (dont use Admin level access).
If you don't specify a destination folder I assume your web service wants to write to "C:\Windows\System32\" or something of that kind. That's why a UnauthorizedAccessException will be thrown on the server. In order to write to the "home"-directory of the web service you have to find out where that is first.
The following works for me but you also find other suggestions here.
Add the reference System.Web, and get the current directory by calling:
strFileDestination = System.Web.Hosting.HostingEnvironment.ApplicationPhysicalPath + strFileName;
Remember to give your service write permission in IIS.
If you're running on Windows 2003 and haven't turned on ASP.NET impersonation, and are running the app in the DefaultAppPool or an application pool that is configured to run under the identity of "Network Service", then you'll need to give the "Network Service" account write permission to the destination folder. If you're running the site in an app pool that is using an identity other than "Network Service" then that account may require write permissions to the destination folder.
If you're running windows 2000 then the '<MACHINENAME>\ASPNET' account will need write permissions to the destination folder.
If you've got impersonation turned on then you'll need to give the site's anonymous user account write permissions to the destination folder instead.
To check if impersonation is turned on, open (assuming ASP.NET 2.0) then check your machine.config file (C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG) to see if you have the following setting:
<identity impersonate="true"/>
This may also be overridden in your application's web.config.
Additionally if you're running in a partial trust environment then you'll likely only be able to write to the website's application folder because the default FileIOPermission is usually set to $AppDir$, i.e. you can't modify files anywhere else, even with the correct NTFS permissions.
If you're writing to a network share then StingyJack has the answer for you, but the partial trust environment considerations still apply.
But check your NTFS perms first, that's probably the best bet.
Hope this helps
Kev
Stuart, instead of using System.IO.Directory.GetCurrentDirectory(), you may want to use Server.MapPath. You can give Server.MapPath the directory relative to the location of your web service where you want to save the file, otherwise you probably need to pass a full file path "C:\Files\file.txt". As far as the permissions issue, I am usually able to resolve this by adding write access to the folder I'm writing the file to for IIS_WPG and ASPNET users (These usernames may be different on your server).
You should be able to write files from web services. This is most likely a permissions or trust issue. If you are in a limited trust (i.e., Medium trust) ensure that you are writing to a patch in or below your web root. If you are already doing that, or are in a full trust environment check to make sure that the directory has permissions for the IIS worker process to write to it.