I'm developing an application that needs to write to the registry. It works fine on XP, but when I run it on Vista, from Visual Studio, I get a security exception in:
Registry.LocalMachine.OpenSubKey("SOFTWARE", true);
I'm trying to write a new key into that branch of the registry.
What's the right way to do this, firstly so that I can run my application from VS on Vista, and secondly so that my users don't run into problems running on Vista.
Thanks...
On both XP and Vista you need Admin rights to write a new key under LocalMachine.
You'll be finding this works on XP and fails on Vista due to different account defaults.
The quick and dirty solution is to ensure your application runs with Admin rights in both cases, though in on Vista this tends to be frowned upon.
The better solution would be to redesign things slightly - can the new sub key be written by your installer (which runs with Admin rights), or could you store your information somewhere else?
Standard users, and admin's running with UAC on Vista, do not have permission to write the the local machine registry key. This would fail on XP too if you ran as standard user.
Your options are:
Use Registry.CurrentUser instead, if the setting is per-user.
Run your app as administrator
Loosen the ACL on the key so anyone
can write - which is definitely
not recommended, since any malware
on the box can toast the key.
You can only write to that key if you're running as administrator. So you'll need to run VS as administrator and your users will need to run the application as administrator.
My suggestion would be to see if you really need to write to LocalMachine. You can write to CurrentUser without admin rights.
I assume it "works under XP" because everybody runs it as Admin under XP?
You will could try to circumvent (create the key during Setup or use a key under CurrrentUser or something).
You could grant the privilege to your Application during Setup. I'm afraid I'm a little short on details on how to do that.
Use Registry.CurrentUser
Related
I've been wrestling with this issue for a few days and can't find any posts that solve it for me. Maybe what I want isn't possible.
We have developed a WinForms application for internal use at our company.
Most employees do not have admin access in windows.
Our application requires admin access to the machine and needs to automatically start when the user logs on.
Here's what I've tried:
1) Putting a Shortcut in the Startup folder
I can get the app to automatically launch (using a relauncher), but it still requires an admin to be at the computer on every restart (to enter the password).
2) Registry Key
I created a Software\Microsoft\Windows\CurrentVersion\Run registry key to automatically start the application. Whether I run the relauncher or the app itself, UAC demands a password on every restart (or relogin).
3) Scheduled Task
I created a scheduled task to automatically start the app on logon using admin permissions on the machine (under use the following account). I also checked the 'Run with highest privileges' box. UAC still pops up on every restart.
4) Windows Service
I tried to run the app as a windows service, but it has a user interface (which is disabled by windows services).
5) Disable UAC for Specific Program
It looks like you can disable UAC for a specific program but that involves downloading the Application Compatibility Toolkit, creating some kind of database, etc. I'd very much prefer that our IT staff wouldn't have to do that at every machine. At this point, it's probably my only option.
It seems like an admin should be able to install an application so that it runs automatically without a prompt. Am I missing a way to do this?
You should make split your program into a non-admin UI, which runs on user startup, and an admin service, which performs the administrative tasks.
To run admin-requiring code from the UI, use WCF to ask the service to do it.
Beware that hostile parties may impersonate the UI and ask the service to do malicious things; you need to carefully figure out what the service should be able to do in response to IPC calls.
Your problem is not a UAC problem, it is a security problem.
And the answer depends on what your application that "requires admin rights" needs to do.
If your application needs to be able to start, and stop services, then the User needs the ability to start and stop services. In which case you need to give the users that privilege.
If the user's need the ability to alter or delete files, then they need that privilege too. In that case it is easier to grant Full Control permissions to Everyone.
If your application needs the ability to modify registry keys in the HKLM tree then you can, again, grant Full Control to Everyone in the registry.
If you need your users to have the ability to modify items, then they need permissions to modify those locations. Granting them those NTFS permissions is not a bad thing; it is exactly what those permissions exist for - to control access.
But why
But then we ask why? What is it you're doing that users need all the rights of an administrator, and all capabilities of an administrator, all the power of an administrator, but you don't want to make them a member of the Administrator's group?
The answer is almost invariably that your internal use application doesn't need to run as an administrator.
What Would XP Do?
The question becomes:
What would you do on Windows XP?
A standard user on Windows XP didn't even have the UAC convenience feature. If a user wanted to run an application an administrator: they had to logout and login as an administrator. How did, or how would, the application work on a system with UAC disabled?
Presumably very little of your application needs to run as admin - the rest would be better running as the unprivileged user. This is very common (think self-updating browsers, for example).
The proper way to do this is to install a service to do the privileged bit, and have the UI communicate with the service.
Our application requires admin access to the machine ...
Why?
You cannot bypass the UAC prompt, and this is by design.
See FAQ: Why can’t I bypass the UAC prompt? for a good discussion of why. Excerpt:
If it were possible to mark an application to run with silently-elevated privileges, what would become of all those apps out there with LUA bugs? Answer: they'd all be marked to silently elevate. How would future software for Windows be written? Answer: To silently elevate. Nobody would actually fix their apps, and end-user applications will continue to require and run with full administrative permissions unnecessarily.
We have an application that needs get from an Administrator account to another limited account and the other way around. Currently we are setting the auto logon in the registry, then reboot the machine. This takes up to 3 reboots as the machines are EWF enabled. Our customer support just cannot sit around and wait for the remote machines to reboot while there's an angry customer on the phone.
We have a windows service and a ui running on the machines (written in C#). Most of them are windows 7, but some are windows xp and windows 8.
I was wondering if anybody here knows a way to maybe trick windows into thinking it was just rebooted and auto log into an account. Anybody know of anything? I do know there are tricky ways to log into an account automatically from the login screen, but as far as I understand that's going to require writing a module to replace GINA in windows XP, and in windows vista and up, since GINA was replaced with a "Content Provider", writing a Content Provider or something, both of which seem overkill, but a possible future solution. Any ideas?
NOTE: We are not switching between accounts so that the application can run a process under that account, we are switching between accounts so real people have either administrative access or limited access to the computer. Hope that makes it a little more clear
If you have an application that needs to run between other users and an administrator, you should be creating a launcher application. The launcher application should be using Process.Start() to start your application. You can supply ProcessStartInfo arguments to Process.Start() so that you can run the application using different credentials.
Here'some help. For Xp, there's a simple registry key that does it (search google for AutoLogon), for Win7, it's a bit more complex. See this topic:
http://answers.microsoft.com/en-us/windows/forum/windows_7-security/how-to-turn-on-automatic-logon-in-windows-7/99d4fe75-3f22-499b-85fc-c7a2c4f728af
I think we had something like this running somewhere, but it wasn't my task and the collegue is on vacation this week. Maybe the above link helps, i'll ask him otherwise.
I am using Visual Studio 2010, and I'm writing a program that needs to set (and read) new registry values under HKLM\Software\myapp
The program is .NET 2.0-based and as for now it runs on Windows 7 64-bit. Here is my ocde:
RegistryKey softwareKey = Registry.LocalMachine.OpenSubKey("Software", true);
RegistryKey MyKey = softwareKey.CreateSubKey("MyApp");
RegistryKey = MyKey.CreateSubKey("MyKey");
selfPlacingWindowKey.SetValue("instaldateperson", datestr + usrname);
The problem I have when running Visual Studio 2010, is that it will run the app but logged on as me, I am a user and member of local admin group.. however I cannot create the key (despite I am part of local admin group, who have rights to do so). Neither do I know how to do it as a logon as (but its also not what I want since then I would put Adminuser and password inside the code, and I already am admin ?? so why ??)
If this isn't possible at all, are there options for creating registry keys?
Somehow add them to the project or so ??.. I am a bit confused here.
Just because you're running as Administrator (or using an account with administrative privileges) does not mean that those administrative privileges are always in effect. This is a security measure, preventing malware from exploiting users who foolishly use their computer all the time with administrative privileges.
To wield your administrative privileges, you need to elevate the process. There are two ways to do this:
Use a manifest that indicates your application requires administrative privileges, and thus demand elevation at startup.
This means your application will always run elevated and should only be used when your application needs this. The Windows Registry Editor (RegEdit), for example, does this, because there's little you can do there without administrative privileges.
Find information about how to accomplish this here on MSDN, or in my answer here. Basically, you just want to add the following line to your manifest:
<requestedExecutionLevel level="requireAdministrator" />
If you only need administrative privileges for certain tasks (i.e., saving a particular setting to the registry) and the rest of your application does not require it, you should launch a new elevated process to do this. There is no way to temporarily elevate the current process, so you actually need to spin off a new process.
The advantage of this method is that your application does not have to run with administrative privileges all the time (which increases security), and that users who do not have administrative privileges will still be able to run your app to do everything else (i.e., everything but the one or two tasks that do require elevation).
You spin off a separate process that contains only the logic needed to write to the registry using the Process class and request elevation for this process using the runas verb. For more information, see this question. I have also written an answer that provides a complete description how to accomplish this from C#, including sample code.
Of course, as other answers have mentioned, it is more likely that the design of your application is incorrect. The whole logic of the Windows security model is that regular applications to not require administrative privileges. They don't need to write to the registry or do other things that could potentially compromise the machine. If you need to persist settings, might I suggest two other possible approaches:
Recognizing that Windows is indeed a multi-user operating system and writing your settings only for the current user. This makes good sense anyway because different users often have different settings and preferences. Instead of the HKEY_LOCAL_MACHINE branch of the registry (which requires administrative privileges to access), you would want to use HKEY_CURRENT_USER. Change your first line of code to:
RegistryKey softwareKey = Registry.CurrentUser.OpenSubKey("Software", true);
Skipping all of the hassle and complication of writing to the registry altogether by using logic built into .NET to persist your application's settings. Start reading the answers here, or here, or on MSDN to learn how to do that. I'd say that this is by far your best option. Don't write complicated code yourself to do something that the framework you use already has built-in support for doing with ease.
The design of your application is probably wrong. Standard desktop apps are not supposed to write to HKEY_LOCAL_MACHINE. Because of UAC, you need to have administrator rights, and be running in an elevated process in order to be able to write to HKLM.
If your application does need to make changes to HKLM then consider doing so at installation time because the installer will be run elevated.
If a desktop application does need to write to HKLM then it should consider separating those parts of the application that need to run elevated into a separate process. Otherwise the users are going to be very fed up with having to go through a UAC dialog in order to run your application. Even if they aren't using the part of the application that writes to HKLM. And if you force the entire app to require elevation then standard users can never run it at all.
The reason you can't create the key under HKEY_LOCAL_MACHINE while running Visual Studio is because Visual Studio isn't running as an elevated process.
For end-users the manifest of the application needs to indicate that full Administrator privileges are required. Here is the documentation on embedding a manifest for UAC
If the registry key doesn't need to be global on the machine consider writing to HKEY_CURRENT_USER instead.
You should to give writable permission adding true value after your key in the method.
Registry.LocalMachine.CreateSubKey(#"YOURKEY", true);
Registry.LocalMachine.OpenSubKey(#"YOURKEY", true);
Also you need elevated permissions to do that, then you can create a .manifest file and setting the level in requireAdministrator like that:
<requestedExecutionLevel level="requireAdministrator" uiAccess="false" />
NOTE:
In your code:
RegistryKey softwareKey = Registry.LocalMachine.OpenSubKey("Software", true);
RegistryKey MyKey = softwareKey.CreateSubKey("MyApp");
RegistryKey = MyKey.CreateSubKey("MyKey");
selfPlacingWindowKey.SetValue("instaldateperson", datestr + usrname);
Check if the object label si correct, you are using the labels softwareKey and MyKey to create an object but to set the value you are using another label selfPlacingWindowKey.
Resuming. Create a .manifest file in your project. Give it the same name as the executable. "name_of_executable.exe.manifest" Finally change or create the tag for:
<requestedExecutionLevel level = "requireAdministrator" uiAccess = "false" />
The previous answers mentioned that you need to specify in the manifest that you require administrator permissions to use HKLM
You can create a manifest by;
Right click on your project,
Going to Add New
Click On General
Click on Application Manifest File
Click Add
Open your manifest file and find and un-comment the requireAdministrator line
The more nuanced thing that may be tripping you up is having Prefer 32bit ticked in your project settings.
This will mean that the Registry can't get the access mask it requires and it will fail silently without an inner exception because the error handler needs the same access mask so it can't be exploited.
You should avoid storing things in this part of the registry unless you absolutely need to persist settings across users, The registry also shouldn't be used to store passwords or other sensitive information as you can NOT reliably control access even with ACLs.
We are about to roll out several hundred new machines running windows 7, with the OS installed via WDS so at the moment we can make changes and sysprep them into the build.
The problem is a .Net app we wrote years ago which itself spawns a modified command shell. That shell runs a dataflex application that itself needs to run with elevated permissions.
We don't grant users any general admin rights.
Is there a mechanism where we can pre-allow our .Net app to run as administrator so that the command control runs as Administrator?
I'm aware of the changes I can make in the app.manifest to require that the program runs as Administrator. I'm not aware of how I can (as an Administrator) configure the machine to allow that to happen without giving the user more rights or credentials than I would want them to have.
Does the application have to run as Administrator, or does it just need access to specific things? If it has a spurious "am I admin" check at startup, you can probably use a shim from the Application Compatibility Toolkit to lie to it, and then configure access permissions to the things that it actually needs.
If that looks like it'll fly, then you'd be better off taking further questions over to serverfault.
What Roger is getting at is that many people assume that if an app doesn't work as a normal user, they have to give it Administrator rights.That's not true in many, if not most cases. You have to find out WHAT specific rights it's failing with, and then assign those rights. This is more work, but it avoids giving general administrator rights to people.
I didnt get correct answer and got lots of answers like "we can not do like this" for my previous questions.
Thats why I decided to explain in detail about my problem please help me if you can or please ask your friend who can answer this.
Now my problem:
Step 1:
I created a C# program which edits various windows registries.
For editing windows registries we must have an Admin privilege.
My program is running fine in Administrator mode without any problem.
Step 2:
I want my program to be run into limited user mode also. If few people didnt get what I am saying here is that I want to run my above C# code into Guest mode.
In guest mode there is a restriction that We can not change Windows Registries.
So as I am executing my Application, I am getting one notification which is asking for Admin Password.
After inserting Admin Password my application is working fine.
Step 3:
I want that my application must not ask Admin password every time in Guest/limited account.
I also want that in Guest mode my Application should work.
I also want that in Guest mode my Application should be able to access and change Windows Registries.
Step 4:
Lot of people replied me that we can not do this in Guest mode since Windows is restricting users to edit windows registries for security purpose. So please if you also feel like this then please do not reply to this question.
I am answering to those people that, all good antivirus which run into Guest mode has access to Windows Registries.
Step 5:
Since I know Admin Password so is there any way of saving Admin password in our C# code and bypass popup message of asking Admin password again and again.
Is there any way that we will instruct Windows that our application will be running in Admin mode and do not ask for Admin password again and again
How Antivirus application running in Guest mode do all the operation like deleting virus from system32 folder and resetting registries after Virus attack. These antivirus application never asks for "We found a virus in System32 folder, Since I am running in Guest mode and unable to delete virus, so please enter Admin password so that I can delete virus"
I hope you understood what i mean to ask?
I want to develop a C# application which should run in any mode (Admin/Guest/Limited) and should be able to Create, Edit and Delete Windows Registries.
Note: Please do not answer this with "right click and Run As Administrator".
To the best of my knowledge, antivirus software solves this problem by running two (or more) processes: a user interface program running as the guest user, and a privileged process (usually a Windows service). The user program is not able to actually manipulate privilege-restricted resources (like secure registry hives) -- instead, it communicates with the privileged process (hopefully in some secure way) and the privileged process performs the privileged action on behalf of the user.
This is the same kind of technique by which programs ever access privileged resources, such as hardware. Your user-level process doesn't (usually) have the right to perform various hardware actions, like remapping memory in the MMU, but the OS does, and you can get the OS to do what you want by asking it to. System calls thunk into kernel mode, which is fully privileged. However, the system call interface limits the kinds of privileged actions which you can take.
I cant help but saying, NO, you cant do admin things under a guest account. And no- you cant programmatically bypass UAC.
Maybe the following 2 workarounds are interresting for you?
I believe antivirus software runs under the System account (can only be installed by an administrator). For your application, you can create a server/client architecture (both running no the same machine) where the server is installed by the administrator (as part of the whole package) and runs by default under the System account. Then you can use the client on the quest account to send commands to the server.
One other solution might be not to use the registry directly but use another underlying datastore which is accessible by a guest account and synchronize that on demand with the registry (startup and shutdown?), so you only need the admin to login once or twice during the run of your app.