ASP.NET app cannot see files - asp.net

I have an ASP.NET web app (VS 2017 Framework 4.5) that works fine in development. When I deploy to the web server and try to reference a file like this:
PdfBitmap tiffImage = new PdfBitmap(item.TIFPageLocation);
It returns a "Can't find file error". I even set up an if File.Exists() test and had the same result.
The file is a reference to another server like this: \\myserver\myvolume1\00\12\7A\00127A90.TIF.
When I run this path on the web server in WinExplorer it finds and open the TIF image in the default viewer. However the web app cannot see it for some reason.
This is likely some permissions issue but I'm not sure where.
Any ideas?
Thanks
Carl

Yes, this is likely a permissions issue. Your web app will probably be running under an account that has limited rights (almost certainly without the rights to access anything on the domain).
You either need to:
a) elevate their rights (be very careful with this)
b) run your site under a new user context created specifically for this site with rights to reach the other server
c) put your images somewhere easier to access.

Check your folder permission it should not have read access cross check that it's worked for me

It was the account the app pool identity was associated with. That need to be set properly.

Related

Where should a .NET Web Application store it's (non database) setting

I am building a Web Application that will be installed many times. The application needs to be able to save certain setting itself upon request.
I have an installer (InnoSetup) but I want to very careful about what permissions I give the Web Application.
I can't use a database.
A default install always leaves the web.config as read-only. (Most secure)
The registry can be problematic. Unless there is a set of keys a DotNet webapp can always write to by default (IIS_IUSR)...
I was considering App_Data, but the default permissions are no longer useful and Inno-Setup can't easily fix it correctly:
https://support.microsoft.com/en-us/kb/2005172
Security and Ease of Setup are both big issues..
I also don't want to make a mess of the machines I install to.
A FAILED solution was to write to the user portion of the registry:
Microsoft.Win32.Registry.CurrentUser.CreateSubKey("Software\\MyCo\\MyApp\\");
var reg = Microsoft.Win32.Registry.CurrentUser.OpenSubKey("Software\\MyCo\\MyApp", true);
reg.SetValue("MyValue", (string)dataString, Microsoft.Win32.RegistryValueKind.String);
But I found out that writing to HKEY_CURRENT_USER is also not allowed by default on Server 2012 and likely others. The server error page is helpful and gives options such as explicitly giving the IUSR_{MachineName} explicit permission but this is a no go for me.
So my final solution is to have the installer create a user configurable folder and then assigning all users Read/Write access to that folder. The administrator can always lock it down more if they want.
If anyone has a better option then let me know.
With InnoSetup I created a new Wizard page to suggest and collect a Data folder from the user. The installer then:
Created that folder and gave All Users Read/Write access,
Added a HKLM registry key telling the Web App where to look for the folder,
Notified the user that they should lock the folder down further to prevent abuse.

Run Batch File in Asp.net C#

I am using asp.net C# 4.0
I have a batch which will open a text file.
Batch File query
ECHO OFF
start D:\accounts\request\08__processing\0377e792-4ca9-4550-b78c-de2bdf26611f.txt
ASp.net Code
System.Diagnostics.Process.Start("D:\\bacthFile.bat");
when i double click on the batch file its opening the text file.But when run above code its not opening any notepad.
it is not showing any exception also.
Please Help
Thanks
This is the wrong way to read a text file from ASP.NET, you need to use System.IO and put files you need to read somewhere where ASP.NET can get at them, eg.. App_data. That said, here is how to do it the wrong way: IIS runs on an invisible virtual window--it's a service. There is a way to get some services to display the UI, I forget how. In any case, you'd have to RDP onto the server, to see such a window after starting the service and goosing it into displaying a UI (this trick might not even work for IIS).
Next, as commenters noted, on IIS, you'll have one set of credentials different from your own (depends on what version of IIS)-- in any case, it will have restricted access and be somewhat sandboxed. If you set up impersonation and windows authentication in the web.config, sometimes you can get your request to run with your credentials.
Next, if the web host runs in medium trust, you might not be able to launch arbitrary apps from the asp.net appdomain.
Finally, the only way this could ever work is if your app is always running locally with casinni (the visual studio development server)-- but in that case, you could simplify things a lot by using a console app instead of asp.net unless you really need the HTML templating, say for output.

System.Security.SecurityException when writing to Event Log

I’m working on trying to port an ASP.NET app from Server 2003 (and IIS6) to Server 2008 (IIS7).
When I try and visit the page on the browser I get this:
Server Error in ‘/’ Application.
Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application’s trust level in the configuration file.
Exception Details: System.Security.SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and the location of the exception can be identified using the exception stack trace below.
Stack Trace:
[SecurityException: The source was not found, but some or all event logs could not be searched. Inaccessible logs: Security.]
System.Diagnostics.EventLog.FindSourceRegistration(String source, String machineName, Boolean readOnly) +562
System.Diagnostics.EventLog.SourceExists(String source, String machineName) +251
[snip]
These are the things I’ve done to try and solve it:
Give “Everyone” full access permission to the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Security. This worked. But naturally I can’t do this in production. So I deleted the “Everyone” permission after running the app for a few minutes and the error re-appeared.
I created the source in the Application log and the Security log (and I verified it exists via regedit) during installation with elevated permissions but the error remained.
I gave the app a full trust level in the web.config file (and using appcmd.exe) but to no avail.
Does anyone have an insight as to what could be done here?
PS: This is a follow up to this question. I followed the given answers but to no avail (see #2 above).
To give Network Service read permission on the EventLog/Security key (as suggested by Firenzi and royrules22) follow instructions from http://geekswithblogs.net/timh/archive/2005/10/05/56029.aspx
Open the Registry Editor:
Select Start then Run. Enter regedt32 or regedit
Navigate/expand to the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security
3. Right click on this entry and select Permissions
Add the Network Service user
Give it Read permission
UPDATE: The steps above are ok on developer machines, where you do not use deployment process to install application.
However if you deploy your application to other machine(s), consider to register event log sources during installation as suggested in SailAvid's and Nicole Calinoiu's answers.
I am using PowerShell function (calling in Octopus Deploy.ps1)
function Create-EventSources() {
$eventSources = #("MySource1","MySource2" )
foreach ($source in $eventSources) {
if ([System.Diagnostics.EventLog]::SourceExists($source) -eq $false) {
[System.Diagnostics.EventLog]::CreateEventSource($source, "Application")
}
}
}
See also Microsoft KB 2028427 Fail to write to the Windows event log from an ASP.NET or ASP application
The problem is that the EventLog.SourceExists tries to access the EventLog\Security key, access which is only permitted for an administrator.
A common example for a C# Program logging into EventLog is:
string sSource;
string sLog;
string sEvent;
sSource = "dotNET Sample App";
sLog = "Application";
sEvent = "Sample Event";
if (!EventLog.SourceExists(sSource))
EventLog.CreateEventSource(sSource, sLog);
EventLog.WriteEntry(sSource, sEvent);
EventLog.WriteEntry(sSource, sEvent, EventLogEntryType.Warning, 234);
However, the following lines fail if the program hasn't administrator permissions and the key is not found under EventLog\Application as EventLog.SourceExists will then try to access EventLog\Security.
if (!EventLog.SourceExists(sSource))
EventLog.CreateEventSource(sSource, sLog);
Therefore the recommended way is to create an install script, which creates the corresponding key, namely:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\dotNET Sample App
One can then remove those two lines.
You can also create a .reg file to create the registry key. Simply save the following text into a file create.reg:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\dotNET Sample App]
The solution was to give the "Network Service" account read permission on the EventLog/Security key.
For me ony granting 'Read' permissions for 'NetworkService' to the whole 'EventLog' branch worked.
I had a very similar problem with a console program I develop under VS2010 (upgraded from VS2008 under XP)
My prog uses EnLib to do some logging.
The error was fired because EntLib had not the permission to register a new event source.
So I started once my compiled prog as an Administrator : it registered the event source.
Then I went back developping and debugging from inside VS without problem.
(you may also refer to http://www.blackwasp.co.uk/EventLog_3.aspx, it helped me
This exception was occurring for me from a .NET console app running as a scheduled task, and I was trying to do basically the same thing - create a new Event Source and write to the event log.
In the end, setting full permissions for the user under which the task was running on the following keys did the trick for me:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Security
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog
I try almost everything in here to solve this problem... I share here the answer that help me:
Another way to resolve the issue :
in IIS console, go to application pool managing your site, and note the identity running it (usually Network Service)
make sure this identity can read KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog (rigth-click, authorisations)
now change the identity of this application pool to Local System, apply, and switch back to Network Service
Credentials will be reloaded and EventLog reacheable
in http://geekswithblogs.net/timh/archive/2005/10/05/56029.aspx , thanks Michael Freidgeim
A new key with source name used need to be created under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application in the regEdit when you use System.Diagnostics.EventLog.WriteEntry("SourceName", "ErrorMessage", EventLogEntryType.Error);
So basically your user does not have permission to create the key. The can do the following depending of the user that you are using from the Identity value in the Application Pool Advanced settings:
Run RegEdit and go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog
Right click in EventLog key and the select Permissions... option
3.Add your user with full Control access.
-If you are using "NetworkService" add NETWORK SERVICE user
-If you are usinf "ApplicationPoolIdentity" add IIS APPPOL{name of your app pool} (use local machine location when search the user).
-If you are using "LocalSystem" make sure that the user has Administrator permissions. It is not recommend for vulnerabilities.
Repeat the steps from 1 to 3 for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Security
For debugging with Visual Studio I use "NetworkService" (it is ASP.NET user) and when the site is published I used "AppicationPoolIdentity".
I ran into the same issue, but I had to go up one level and give full access to everyone to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\ key, instead of going down to security, that cleared up the issue for me.
Same issue on Windows 7 64bits.
Run as administrator solved the problem.
There does appear to be a glaringly obvious solution to this that I've yet to see a huge downside, at least where it's not practical to obtain administrative rights in order to create your own event source: Use one that's already there.
The two which I've started to make use of are ".Net Runtime" and "Application Error", both of which seem like they will be present on most machines.
Main disadvantages are inability to group by that event, and that you probably don't have an associated Event ID, which means the log entry may very well be prefixed with something to the effect of "The description for Event ID 0 from source .Net Runtime cannot be found...." if you omit it, but the log goes in, and the output looks broadly sensible.
The resultant code ends up looking like:
EventLog.WriteEntry(
".Net Runtime",
"Some message text here, maybe an exception you want to log",
EventLogEntryType.Error
);
Of course, since there's always a chance you're on a machine that doesn't have those event sources for whatever reason, you probably want to try {} catch{} wrap it in case it fails and makes things worse, but events are now saveable.
FYI...my problem was that accidently selected "Local Service" as the Account on properties of the ProcessInstaller instead of "Local System". Just mentioning for anyone else who followed the MSDN tutorial as the Local Service selection shows first and I wasn't paying close attention....
I'm not working on IIS, but I do have an application that throws the same error on a 2K8 box. It works just fine on a 2K3 box, go figure.
My resolution was to "Run as administrator" to give the application elevated rights and everything works happily. I hope this helps lead you in the right direction.
Windows 2008 is rights/permissions/elevation is really different from Windows 2003, gar.
Hi I ran into the same problem when I was developing an application and wanted to install it on a remote PC, I fixed it by doing the following:
1) Goto your registry, locate: HKLM\System\CurrentControlSet\Services\EventLog\Application(???YOUR_SERVICE_OR_APP_NAME???)
Note that "(???YOUR_SERVICE_OR_APP_NAME???)" is your application service name as you defined it when you created your .NET deployment, for example, if you named your new application "My new App" then the key would be: HKLM\System\CurrentControlSet\Services\EventLog\Application\My New app
Note2: Depending on which eventLog you are writing into, you may find on your DEV box, \Application\ (as noted above), or also (\System) or (\Security) depending on what event your application is writing into, mostly, (\Application) should be fine all the times.
2) Being on the key above, From the menu; Select "FILE" -> "Export", and then save the file. (Note: This would create your necessary registry settings when the application would need to access this key to write into the Event Viewer), the new file will be a .REG file, for the argument sake, call it "My New App.REG"
3) When deploying on PRODuction, consult the Server's System's administrator (SA), hand over the "My New App.REG" file along with the application, and ask the SA to install this REG file, once done (as admin) this would create the key for your applicaion.
4) Run your application, it should not need to access anything else other than this key.
Problem should be resolved by now.
Cause:
When developing an application that writes anything into the EventLog, it would require a KEY for it under the Eventlog registry if this key isn't found, it would try to create it, which then fails for having no permissions to do so. The above process, is similar to deploying an application (manually) whereas we are creating this ourselves, and no need to have a headache since you are not tweaking the registry by adding permissions to EVERYONE which is a securty risk on production servers.
I hope this helps resolving it.
Though the installer answer is a good answer, it is not always practical when dealing with software you did not write. A simple answer is to create the log and the event source using the PowerShell command New-EventLog (http://technet.microsoft.com/en-us/library/hh849768.aspx)
Run PowerShell as an Administrator and run the following command changing out the log name and source that you need.
New-EventLog -LogName Application -Source TFSAggregator
I used it to solve the Event Log Exception when Aggregator runs issue from codeplex.
Had a similar issue with all of our 2008 servers. The security log stopped working altogether because of a GPO that took the group Authenticated Users and read permission away from the key HKLM\System\CurrentControlSet\Services\EventLog\security
Putting this back per Microsoft's recommendation corrected the issue. I suspect giving all authenticated users read at a higher level will also correct your problem.
I hit similar issue - in my case Source contained <, > characters. 64 bit machines are using new even log - xml base I would say and these characters (set from string) create invalid xml which causes exception. Arguably this should be consider Microsoft issue - not handling the Source (name/string) correctly.
My app gets installed on client web servers. Rather than fiddling with Network Service permissions and the registry, I opted to check SourceExists and run CreateEventSource in my installer.
I also added a try/catch around log.source = "xx" in the app to set it to a known source if my event source wasn't created (This would only come up if I hot swapped a .dll instead of re-installing).
Solution is very simple - Run Visual Studio Application in Admin mode !
I had a console application where I also had done a "Publish" to create an Install disk.
I was getting the same error at the OP:
The solution was right click setup.exe and click Run as Administrator
This enabled the install process the necessary privilege's.
I had this issue when running an app within VS. All I had to do was run the program as Administrator once, then I could run from within VS.
To run as Administrator, just navigate to your debug folder in windows explorer. Right-click on the program and choose Run as administrator.
try below in web.config
<system.web>
<trust level="Full"/>
</system.web>
Rebuilding the solution worked for me

ClearCase dynamic view contents not visible to ASP.NET web application

I am running an asp.net application (VS2008/.net 3.5) and when running it under VS in debug more it works fine.
It reads files and directories from a network share happily.
I can run "cleartool startview [dynamic view name]" ok, I can "cleartool mount [vob]" happily.
But if I try to test for the existance of a file within the vob it can't see it.
So I tried something different, I now run "cleartool ls -short -vob_only [filename]" to test for existance.
For both of those it works fine running under VS2008 but won't work when running under IIS post deployment.
I have the set and the user has valid access to ClearCase.
Any ideas?
If you use the built-in webserver (Cassini) during development the webserver is running as you and have access to your networked drives etc. IIS on the other hand uses a different user account and doesn't share your user profile including your ClearCase views etc. That may explain your problems.
I found the problem and a resolution to this. The problem is that ClearCase is using the process user for authentication whereas the shared drive access mentioned in the original question is using the thread user.
The reason for this is the when accessing ClearCase it spawns off a new process - and child processes always use the parents process security context and not the current thread's.
The way around this was to run the web application within its own application pool which is running as a user with rights to access ClearCase. An inflation of rights beyond what should be really necessary however it did the trick.

Should the Network Service Account receive temp file permissions by default?

Recently I was working with generating a PDF from Crystal Reports through a webform. It was failing, which I determined to be caused by the permissions settings on the c:\windows\temp dir. I gave the Network Service account full access to this folder, which promptly fixed the issue. But is there a reason the Network Service account didn't have these permissions by default?
Rick Strahl asks this question here. It sounds like there shouldn't be any issues with doing this, but Rick wasn't clear on why the default is set that way.
Web Server is Windows Server 2003
These days, the default option will tend to be the more secure one. I don't think there's any other reason.
I've had the same issue as you, and in my environment just gave the permission and moved on.
This post suggests it is the fault of Crystal Reports, which is explicitly referencing %WINDIR%\Temp instead of using an API such as Path.GetTempPath(). In fact I have seen Path.GetTempPath() return %WINDIR%\Temp when running under the Network Service account on Windows 2003.
This post on creating temp files has comments that support using the windows temp folder.
An msdn article on using the Network Service account states that "if your ASP.NET application needs to use files or folders in other locations, you must specifically enable access" This tells me that the default restriction to the temp folder isn't because the temp folder was singled out, but that all other locations besides the IIS root folder are restricted by default.
%windows%\temp is not for general temp'ing and barfing around. It is crystal clear that Crystal Reports is abusing that directory. This happens a lot when developers are too lazy to boot up their machines with anything but an admin account.
Every user (including Network Service) has their own temp space, with full access rights, under Documents & Settings. Winners don't act like CR, and use their own temp spaces.
In short, there is nothing wrong with default permissions on win\temp. I believe it is simply meant for Windows' internal workings. (Then again, it would be much better for everyone concerned, if that directory never existed in the first place.)

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