Hi Guys any help would be much appreciated.
We have an application that’s installed at several locations but we are having an issue at one particular site. In short the application settings (My.) are not being saved after a reboot. The application is build in VB.Net v3.5 Framework and we are not experiencing any issues elsewhere.
This particular site is using roaming profiles and the network administrator ensures us that the correct permissions are applied to the user account(s) and all application data is being saved to the server. I’ve asked the network admin to check for the existence of the user settings file user.config in the Application Data directory and he says it doesn’t exist.
In our application we store the connection string to the database in the application settings under the user scope. If no connection string is present or if one is present and a connection to the database cannot be made then a form is shown asking the user for the database credentials. Each morning when the users boot the machine and opens the application for the first time they are asked for these credentials but if they close the application and restart it they are not asked for them. This indicates to us that the settings are being saved but once the pc is rebooted and the application is opened for the first time they are asked for the database credentials. This seems like the settings are not persisting after a reboot.
Any thoughts/feedback would be much appreciated.
I'm wondering if it's Code Access Security preventing the file from being written?
If the sysadmin at trouble site has implemented group policy folder redirection, the user's local/roaming profile could be getting stored on a network fileshare. Code Access Security is fairly picky about letting code read/write to/from network resources.
I'm sorry that I don't have more details than this, and I didn't find any sure-fire hits on google, but searching for "code access security", "fulltrust" and any network/fileshare keywords you can think of may get you farther.
Related
Sorry if this is a repeat but I'm not seeing anything else relating to this. Running the diagnostics page, it reports that the license file could not be written to app_data due to lack of permissions. The app is running under windows auth with impersonation, and the logged in user definitely has write/modify permission on app_data (many other files are written in there by the user).
So what does this mean? It suggests to me that the file write is not using the impersonated credentials. If so, then what credentials is it using?
Thanks for your help.
Chris
I have a database sitting on a domain which is to be used by a VB application.
The domain is not a company wide domain, it is just in use by people at that site.
This application now has to be used by other members of staff who are not on the domain and are not on the same site. When attempting to log into the application the following error message is appearing
The Microsoft office access database engine cannot open or write to the file [Database Path] It is already opened exclusively by another user, or you need permission to view and write its data
The connection string in the application is
"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=\\ServerIP\Folder\Filename.accdb; persist security info = false;"
So I am assuming that this is being blocked by the domain, I have give the folder where the database sits full user permissions for the NETWORK SERVICE user hoping this would fix it but to no avail, so how can I fix it for users to log into the app? Can I make a user on the domain and tell the application to connect as that user? if so can anyone give me an example of some code or point me towards an example? or is there another way to do this that I havent thought of?
I am attempting to set up an IIS 6.0 application running on Windows Server 2003 to use impersonation in order to avoid having to give users direct read/write access to the shared folders where the DB and web pages are stored. Can anyone provide me with details of how this can be set up to work in conjunction with Windows Integrated Authentication?
So far, I can tell that the web.config file (not sure whether it's the correct one) has the two lines mentioned on this thread (Impersonation in IIS 7.0) to allow impersonation and use the Windows logon method. However, users are still prompted for a logon and then told they are not authorized to view web pages. They can view pages if we turn anonymous logon "on", but then their user credentials aren't passed on to the site and therefore they can't access most of it.
I'm fairly inexperienced, so I'm a bit lost here. Thank you very much in advance for the help!
Thanks to intervention from Microsoft (definitely worth the flat fee they charge per incident), we were able to identify the problem. Instead of using the network path to identify the website location on the "Home Directory" tab of the IIS properties, we were using the local drive path. That was all that needed to be changed.
Once we switched to the network path and added a dedicated service account to "Connect As...", impersonation started working right away. Users pass their logged on credentials via integrated authentication (no logon required) and the service account takes care of executing their actions on the database file.
Access to the shared folder is limited to a brief list of administrators, and data access on the web application is limited based on user names.
If anyone is stuck with this and needs help, let me know!
This message appears every time I try to save the data to the DB.
Failed to update database because the database is read only
Note: This error comes only when the application is installed to C drive.
Front End: VB.NET
Back End:SQL Server
Is there any way to overcome this issue?
Or any way to restrict the user from installing the application on C drive?
I would check the file system privileges. I suppose you talk about an SQL server file database. You receive the message because the account trying to access your file database does not have the file system permissions to do so.
In order to confirm my suggestion, you allow everyone to access the specific directory with full permissions.
Then, you have to check what is the account trying to do the actual access. Probably it's a system account (user ASPNET or NETWORK SERVICE). You have to give the respective permissions to the specific account.
Then, restart IIS.
If you want to do this for a distributed stand-alone application. Then these permissions would have to change on each machine where the program would be installed. In order to avoid putting users in such a fuss, the setup program should do it. I am not an expert on setup programs, but even the simplest ones would give you the option to do it, after asking the system adminstrator's approval. I suppose you could build a custom action during the setup program which would change the specific folder's permissions, perhaps by using xcacls.exe.
Hope I helped!
When an ASP.NET application is running under IIS6.0 in Windows 2003 Server with impersonation, what user account is relevant for deciding file read/write/execute access privileges? I have two scenarios where I am trying to understand what access to grant/revoke. I thought the most relevant user is probably the identity specified in the Application Pool, but that doesn't seem to be the whole story.
The first issue concerns executing a local batch file via System.Diagnostics.Process.Start()--I can't do so when the AppPool is set to IWAM_WIN2K3WEB user, but it works fine if it is set to the Network Service identity. I of course made sure that the IWAM user has execute rights on the file.
The second involves writing to a file on the local hard drive--I'd like to be able to prevent doing so via the access control list via folder properties, but even when I set up all users in the folder as "read" (no users/groups with "write" at all), our ASP.NET still writes out the file no problem. How can it if it doesn't have write access?
Google search turns up bits and pieces but never the whole story.
what user account is relevant for [..] file read/write/execute access
As a rule: Always the user account the application/page runs under.
The IWAM account is pretty limited. I don't think it has permissions to start an external process. File access rights are irrelevant at this point.
If a user account (Network Service in your case) owns a file (i.e. has created it), it can do anything to this file, even if not explicitly allowed. Check who owns your file.
Process Monitor from Microsoft is a great tool to track down subtleties like this one.
A bit more searching reveals that the IWAM user isn't that well documented and we should stick with NETWORK SERVICE or a manually-supplied identity if we want to specify permissions for that user.