c# update program files with non administrator user permissions - c#

as you know, C:\Program Files is a restricted folder and Only administrators can modify the contents of this folder.
my c# application has ability to update him self. so i need to download some files programmatically from server and replace them with old files. those files are in Program Files. what can i do about it?

You're pretty stuck, if you need to have your application run anywhere that requires Administrator privilege to update. You are forced to elevate your process's privilege to administrator level to perform your update.
A solution to this problem is to install your application somewhere else--someplace that does not require administrator privilege.

You are going to need to spawn a helper application, that will escalate to get the appropriate permissions, copy the new binary where it needs to go, and exits. Perhaps you can use copy.exe in conjunction with a Process.Start that knows to escalate. This SO article seems to indicate you can do it without too much trouble. However, there is no way around the admin rights if your program lives in C:\Program Files

Related

How to access permission to files after installation?

Today I finally ended creating my app.
To install app I used "setup project" from Visual Studio 2019 (image of project type). App is written in C# .NET 4.7.2 Framework.
So I added some folders and files (image of files and folders here). So I gave my friend *.msi file, he istalled that and something happened - path access denied.
I was surprised because when I installed, everything worked, but on my friend's PC when app is trying to write something in file, it gives result that it cannot open it (just doesn't have permission).
My friend went to properties of those files and he didn't have writing permissions (image here in polish language). In that picture in Polish, zapis
mean "writing", so here is my question: how to make setup project in Visual Studio which gives permission to folders/files to modify them?
In general apps don't have permission to write files to the program folders without elevated permissions. Most apps should write data to the users %appdata% folder you can access that path in c# using:
Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
Every work on files and folders must be in Users\user folders, in Documents\folder or in the registry. You shouldn't give permissions to the user to modify files on the system or Program Files.
Although windows installer is able to set file permissions, you should not write anything in Program Files. And you should not grant write permissions there due to security considerations and best practices. So, you need to inspect your code and change all places where you are trying to write in a Program Files (or in the folder where your application is placed) to write somewhere else. For example, in the %temp% folder, in the Program Data or in specific folder inside a user's Documents folder or even ask user to specify write location explicitly.

Unable to delete files in "Program Files\my app" folder : System.UnauthorizedAccessException :Access to the path '' is denied

I am trying to create an updater which will replace the files in the folder without needing an installer. As part of this process, I need to be able to delete old files and replace them by new files. I tried it and got an UnAuthorizedException. I am runing the updater as administrator. I tried the following
a. Setting the file and folder attribute to Normal
[Access to the path is denied when trying to delete a certain directory
b. Taking ownership of the folder and files contained in it
[Taking ownership of a file or folder
c. Changing the permissions and giving all users full control over the folder and files [Using a custom action in the installer]
[How to give Read/Write permissions to a Folder during installation using .NET
d. Running the updater from a windows service
There is no difference in the results. I keep getting the access denied error. What do I do so that the updater can delete the files?
It's not clear exactly what you mean by "running as administrator", but being logged in as administrator and running a program does not mean that the program is running with elevated privilege, which is what it really needs. But clearly the updater program is not running elevated.
So the issue might be that this updater program of yours needs an elevation manifest so that when you run it, it will ask for elevation with a UAC prompt.
Having said that, simply replacing files that were installed with a Windows installer MSI is not supported. The files must be replaced with a Windows Installer update such as a patch .msp file or an upgraded MSI file. Windows Installer keeps track of every file installed, and it's version and whether it's been updated or not, as well as a filehash. Replacing a file without using Windows Installer can result in unexpected demands for the original MSI file in order that Windows can restore the files to their original installed state. You might find that going to Programs&Features (or right-clicking the MSI file) and choosing repair will also restore them.

Self Deleting Executable (Uninstaller)

I'm trying to make an uninstaller.
I basically need to be able to remove a directory in the program files that contains the uninstaller.
I was thinking to have the uninstaller create a copy of itself to the temp folder,
then have the uninstaller running from the program folder open the uninstaller in temp and close itself where it continues the uninstall.
Problem is, how do I delete the uninstaller in the temp folder...
Check out: https://www.catch22.net/tuts/win32/self-deleting-executables
He has multiple solutions - but mostly aimed at C++ code.
I am currently trying to implement the "DELETE_ON_CLOSE" method in C#.
A comment to all the nay-sayers: MSI does not solve this problem in all cases. In my case, my application needs to install to a network folder, where any network user can run the app. It also needs to support upgrades and uninstalls from any network workstation - not necessarily the same workstation that installed the app. This means I cannot register an Uninstaller into the Add/Remove Programs list on the local machine. I must create an Uninstall.exe that is dropped into the install folder. MSI does not support that, so I have to write my own.
Even though I agree with everyone saying you shouldn't do that, what you can do is:
Have your program create an executable (and config file) in the temporary folder of the OS it's working on.
Have your program start it as an independent process, then exit.
That executable then calls back the actual setup stuff.
Once the setup is done, the temporary executable can delete the setup files.
Since the only trace of your program is now in the temp folder, it will eventually get cleared automatically.

File redirection from Program data to AppData\Local\VirtualStore\ProgramData

I am using C# with .net 3.5
I am saving my program data in a file under: C:\Program Data\MyProgramName\fileName.xml
After installing and running my application one time I uninstalled it (during uninstallation I'm removing all the files from "program data")
and then I reinstall the application, and ran it.
The strange thig is that my application started as if the files in program data existed - means, I had old data in my app even though the data file was deleted.
When running:
File.Exists("C:\Program Data\MyProgramName\fileName.xml")
I got "true" even though I knew for sure that the file does not exist.
The thing became stranger when I ran the application as admin and then the file didn't exist.
After a research, I found out that when running my application with no admin priviliges instead of getting: "C:\Program Data\MyProgramName\fileName.xml" I get "C:\Users\userName\AppData\Local\VirtualStore\ProgramData\MyProgramName\fileName.xml"
and indeed there was a file that existed from the previous installation (that I obviously didn't delete ,because I didn't know it existed).
So apparentlly there is some virtual path to the file under program data.
EDIT :
I found out that after deleting the old file in the virtual store, my application is suddenly able to find the correct file. (I didn't make any changes in the file under Program Data.
My question is:
why is it happen.
How can I prevent it from happening
Thanks in advance
Do you actually have to write to the per-system Program Data folder instead of the per-user Application Data folder(s)?
You might want to take a look at Environment.GetFolderPath and the following Environment.SpecialFolders:
Environment.SpecialFolder.ApplicationData - data folder for application data, synchronized onto domain controller if the user profile is roaming
Environment.SpecialFolder.LocalApplicationData - data folder for application data, local and not synchronized (useful for, for instance, caches)
EDIT:
Tested on Windows 7 x64, non-administrator user.
var appData = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData);
var myFolder = Path.Combine(appData, "MyApp");
if(!Directory.Exists(myFolder)) Directory.CreateDirectory(myFolder);
File.WriteAllText(Path.Combine(myFolder, "Test.txt"), "Test.");
This does what is expected, ie. writes into C:\ProgramData\MyApp\Test.txt. As far as I can tell (Administrator mode Command Prompt), there's no UAC virtualization going on either.
Double edit:
I guess what's happened is that at some point an Administrator user has written the files into your ProgramData folder, and as such, UAC file system virtualization kicks in and redirects the non-administrator writes into the VirtualStore.
Does your uninstaller run as Administrator? If it does, you might have to check both the VirtualStore path for the user who initiates the uninstall, and the actual file system path for program data to remove. I'm not sure if there's an official way to do this, though...
I found the reason for the bug.
the application is trying to take ownership on the file and then the other file is created.
I removed that line and now everything works just fine.

C# vista does not giving access to create folder

In my project I have to create some files and directories into my app folder which is into program files. But in vista it is giving me error that I dont have access to create file.
What should I do now for giving access ? Also it not let me access the registry !!
The program folder is not the place to store application data. There is an %APPDATA% folder for that - you are supposed to store your data there.
Use System.Environment.SpecialFolder and System.Environment.GetFolderPath to obtain the path leading to the correct directory.
Also, you need to differentiate between just creating a folder and putting some files in there (for example during installation) or writing to the program folder at runtime, while typically running under a limited account.
The reason for this difference is simply that installation routines and setups run with elevated privileges under Vista / Windows 7, thus those are allowed to create folders and files there. Still, those files are not supposed to be written to at runtime of your application.
So, what is it you want to do? Write data at runtime, or put some files (i.e. dependencies) in your application folder at a single time? If it's the first, comply with the rules and use the %APPDATA% folder. If it's the second, create an installer / setup routine.
Vista and Win 7 have the Program Files folder locked down so you can't write to it with a basic user account. If you need to create folders there, then you should do it in the installer. Otherwise you can use the user's Application Data folder in their profile.
The only other way is to modify the permissions on the installation folder at install time.
Can you turn the UAC off? Or Login as administrator? The chances are that you are creating the folder in the wrong place.

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